U.S. patent application number 09/963793 was filed with the patent office on 2003-07-17 for disposable cartridge for a blood perfusion system.
Invention is credited to Carson, Gary A., Ellingboe, Bruce S., Kappus, John J., Kollar, Kevin J..
Application Number | 20030135152 09/963793 |
Document ID | / |
Family ID | 38271702 |
Filed Date | 2003-07-17 |
United States Patent
Application |
20030135152 |
Kind Code |
A1 |
Kollar, Kevin J. ; et
al. |
July 17, 2003 |
Disposable cartridge for a blood perfusion system
Abstract
A disposable cartridge for use in extracorporeal blood
perfusions systems that have a control unit for controlling the
flow of fluids. The cartridge has a housing defining a plurality of
internal passageways that connect to a cardiopulmonary circuit, a
cardioplegia circuit and a suction circuit. The cartridge may be
fitted with one or more of a bubble trap, a filter, and a
valve.
Inventors: |
Kollar, Kevin J.; (Ada,
MI) ; Ellingboe, Bruce S.; (Littleton, CO) ;
Kappus, John J.; (Denver, CO) ; Carson, Gary A.;
(Golden, CO) |
Correspondence
Address: |
POPOVICH & WILES, PA
80 SOUTH 8TH STREET
SUITE 1902
MINNEAPOLIS
MN
55402
|
Family ID: |
38271702 |
Appl. No.: |
09/963793 |
Filed: |
September 26, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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60235838 |
Sep 27, 2000 |
|
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Current U.S.
Class: |
604/35 |
Current CPC
Class: |
A61M 1/3624 20130101;
A61M 1/3639 20130101; A61M 1/3644 20140204; A61M 1/3621 20130101;
A61M 1/3641 20140204; A61M 1/3632 20140204; A61M 2205/128 20130101;
A61M 2209/082 20130101; A61M 2205/707 20130101; A61M 1/322
20140204; A61M 1/3666 20130101; A61M 2205/123 20130101; A61M 1/3664
20130101; A61M 1/3643 20130101; A61M 1/3613 20140204; A61M 1/3626
20130101; A61M 2205/505 20130101; A61M 1/3663 20130101; A61M 1/3667
20140204; A61M 2205/3389 20130101; A61M 1/32 20130101; A61M
2205/705 20130101 |
Class at
Publication: |
604/35 |
International
Class: |
A61M 001/00 |
Claims
What is claimed is:
1. A disposable cartridge for use in an extracorporeal blood
perfusion system having a cardiopulmonary circuit for receiving
venous blood from a patient, oxygenating the blood and returning
the oxygenated blood to the patient, a cardioplegia circuit for
delivering a cardioplegia solution to the patient, and a suction
circuit for withdrawing blood or fluids from the patient or
surgical site, the perfusion system having a control unit for
controlling the flow of fluids in one or more of the circuits, the
disposable cartridge comprising: a housing defining a plurality of
internal passageways, a first internal passageway being configured
for connection to the cardiopulmonary circuit, a second internal
passageway being configured for connection to the cardioplegia
circuit and a third internal passageway being configured for
connection to the suction circuit.
2. The disposable cartridge of claim 1 further comprising: a filter
configured for filtering fluid flowing through at least one of the
plurality of internal passageways.
3. The disposable cartridge of claim 1 further comprising: a bubble
trap configured for removing bubbles from fluid in at least one of
the plurality of internal passageways.
4. The disposable cartridge of claim 1 wherein the housing
comprises a first rigid portion connected to a second flexible
portion.
5. The disposable cartridge of claim 4 wherein the first portion
comprises a translucent material configured to allow viewing of
fluid in the internal passageways.
6. The disposable cartridge of claim 1 further comprising at least
one valve interconnected to at least two of the plurality of
internal passageways, the valve being configured for selectively
preventing fluid flow in at least one of the plurality of internal
passageways.
7. The disposable cartridge of claim 1 wherein the housing defines
a plurality of fluid inlet ports and outlet ports.
8. The disposable cartridge of claim 1 wherein the housing further
defines an internal reservoir fluidly connected to at least one of
the internal passageways.
9. The disposable cartridge of claim 1 further comprising a sample
port configured for withdrawing a fluid sample from at least one of
the plurality of internal passageways.
10. The disposable cartridge of claim 4 wherein the control unit of
the perfusion system includes at least one fluid pressure sensor
and wherein the disposable cartridge further includes at least one
pressure sensing station connected to at least one of the plurality
of internal passageways, the pressure sensing station being
configured to interface with the pressure sensor on the control
unit through the flexible portion of the housing.
Description
FIELD OF THE INVENTION
[0001] This invention relates to blood perfusion systems. In
particular, this invention relates to a disposable cartridge for
the flow of fluids in a blood perfusion system.
BACKGROUND OF THE INVENTION
[0002] In general, blood perfusion entails forcing blood through
the vessels of a bodily organ. For such purposes, blood perfusion
systems typically entail the use of one or more pumps in an
extracorporeal circuit that is interconnected with the vascular
system of a patient.
[0003] Of particular interest, cardiopulmonary bypass surgery
requires a perfusion system that provides for the temporary
cessation of the heart to create a still operating field by
replacing the function of the heart and lungs. Such isolation
allows for the surgical correction of vascular stenosis, valvular
disorders, and congenital heart defects. In perfusion systems used
for cardiopulmonary bypass surgery, an extracorporeal blood circuit
is established that includes at least one pump and an oxygenation
device to replace the functions of the heart and lungs.
[0004] More specifically, in cardiopulmonary bypass procedures
oxygen-poor blood, i.e., venous blood, is gravity-drained or
suctioned from a large vein entering the heart or other veins in
the body (e.g., femoral) and is transferred through a venous line
in the extracorporeal circuit. The venous blood is pumped to an
oxygenator that provides for oxygen transfer to the blood. Oxygen
may be introduced into the blood by transfer across a membrane or,
less frequently, by bubbling oxygen through the blood.
Concurrently, CO.sub.2 is removed across the membrane. The
oxygenated blood is then returned through an arterial line to the
aorta, femoral, or other artery.
[0005] In addition to the above-noted components, extracorporeal
fluid circuits used for cardiopulmonary bypass procedures also
typically provide for the flow of a cardioplegia mixture through a
cardioplegia line into the root of the aorta, coronaries and/or
coronary sinus in order to nourish, arrest, and maintain the arrest
of the heart. The cardioplegia mixture is typically circulated
through a heat exchanger prior to patient delivery. Additional
devices that can be employed include a reservoir to hold the venous
blood, a heat exchanger to cool or heat the returned blood, and
various filters to keep particles greater than a predetermined size
from passage into the patient.
[0006] Further, extracorporeal fluid circuits utilized during
cardiopulmonary bypass procedures may also include various suction
lines. Such lines are employed to remove blood that collects in the
thoracic cavity during surgery. Such blood may contain debris such
as skin, air, bone chips, etc. and may be salvaged via filtering
and routed to a reservoir for subsequent washing and/or oxygenation
and return to the patient. A vent line may also be utilized to
remove blood that accumulates in the heart or vasculature (e.g.,
aortic root, pulmonary artery, etc.) during the bypass procedure.
Removal of such accumulated blood may be important to avoid heart
distention. The vented blood may be routed to a reservoir for
subsequent oxygenation and return to the patient or washing. In
addition to the above-noted components, extracorporeal fluid
circuits utilized in connection with cardiopulmonary bypass
procedures may include components for the introduction into the
blood of various nutrients and pharmaceuticals.
[0007] The various fluid circuitry and components of an
extracorporeal circuit are set up by medical personnel prior to the
bypass procedure. This can be a time consuming process since many
of the connections are made by hand. As will be appreciated, this
set-up procedure is also the source of potential error. Any
incorrect or leaky connection can jeopardize both the success of
the surgical procedure and the safety of the patient. Further, such
an approach has entailed the separate setup and monitoring of each
circuit by medical personnel during the course of a cardiopulmonary
bypass procedure. Further, establishment of the operative
interrelationships between the various circuits has been left to
the attention and coordination of medical personnel. In view of the
foregoing it would be desirable to have an integrated perfusion
system which is easy to set-up, use and monitor during the bypass
procedure. Such a system should eliminate many of the sources of
error in the set-up, monitoring and use of conventional
extracorporeal perfusion circuits as well as improve system
monitoring and safety. The present invention comprises an
integrated perfusion system which overcomes many of the
disadvantages of present perfusion systems.
SUMMARY OF THE INVENTION
[0008] In view of the foregoing, one objective of the present
invention is to provide a blood perfusion system that provides for
simplified set-up and interconnection/disconnection of various
disposable components with monitoring/control components.
[0009] Relatedly, another objective of the present invention is to
provide a blood perfusion system that provides for both
enhanced/simplified monitoring and control over various operating
parameters during a medical procedure, and that concomitantly
yields system performance advantages.
[0010] Yet another objective of the present invention is to provide
a blood perfusion system that readily provides medical personnel
with information to facilitate setup and/or to facilitate
operation, parameter monitoring and alarm response during perfusion
procedures.
[0011] An additional objective of the present invention is to
provide a blood perfusion system that maintains a wide range of
configurability for customized use by medical personnel on a
patient-specific basis.
[0012] One or more of the above-noted objectives and additional
advantages are provided by the blood perfusion system disclosed
herein. The system integrates one or more fluid lines and
flow-through components in a disposable assembly that operatively
interfaces with integrated fluid monitoring/flow control components
of a control unit. Additional objectives and advantages may also be
realized in the present invention via the provision of a
multifunctional, graphic user interface that is operatively
interconnected with fluid monitoring/flow control componentry in
the disclosed system.
[0013] In one aspect, this invention is a disposable cartridge for
use in an extracorporeal blood perfusion system having a
cardiopulmonary circuit for receiving venous blood from a patient,
oxygenating the blood and returning the oxygenated blood to the
patient, a cardioplegia circuit for delivering a cardioplegia
solution to the patient, and a suction circuit for withdrawing
blood or fluids from the patient or surgical site, the perfusion
system having a control unit for controlling the flow of fluids in
one or more of the circuits, the disposable cartridge comprising a
housing defining a plurality of internal passageways, a first
internal passageway being configured for connection to the
cardiopulmonary circuit, a second internal passageway being
configured for connection to the cardioplegia circuit and a third
internal passageway being configured for connection to the suction
circuit.
[0014] The disposable cartridge may further comprise a filter
configured for filtering fluid flowing through at least one of the
plurality of internal passageways and/or a bubble trap configured
for removing bubbles from fluid in at least one of the plurality of
internal passageways. The housing may comprise a first rigid
portion connected to a second flexible portion. The first portion
may comprise a translucent material configured to allow viewing of
fluid in the internal passageways. The disposable cartridge may
further include at least one valve interconnected to at least two
of the plurality of internal passageways, the valve being
configured for selectively preventing fluid flow in at least one of
the plurality of internal passageways. The housing may define a
plurality of fluid inlet ports and outlet ports. The housing may
further define an internal reservoir fluidly connected to at least
one of the internal passageways.
[0015] The disposable cartridge may further comprise a sample port
configured for withdrawing a fluid sample from at least one of the
plurality of internal passageways. The control unit of the
perfusion system may include at least one fluid pressure sensor and
the disposable cartridge may further include at least one pressure
sensing station connected to at least one of the plurality of
internal passageways, the pressure sensing station being configured
to interface with the pressure sensor on the control unit through
the flexible portion of the housing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 illustrates a cardiopulmonary bypass system
embodiment of the present invention.
[0017] FIG. 2A illustrates one embodiment of a disposable assembly
for use in the system embodiment of FIG. 1.
[0018] FIG. 2B illustrates the disposable assembly of FIG. 2A
[0019] FIG. 3A is a schematic diagram illustrating the interface
between components of the disposable assembly and component
interface region embodiments of FIGS. 2A and 2B, respectively.
[0020] FIG. 3B is a schematic diagram illustrating the interface
between components of an alternate embodiment of a disposable
assembly and a corresponding alternate embodiment of a component
interface region.
[0021] FIG. 4 is a perspective view of the component interface
region of the embodiment of FIG. 3A showing the cartridge, valve,
arterial filter, and sensor interfaces.
[0022] FIGS. 5A and 5B are perspective views of the venous entry
module of FIGS. 3A and 3B; FIGS. 5C and 5D perspective views of the
mounting bracket for the module of FIGS. 5A and 5B; FIG. 5E is a
sectional view of the module of FIGS. 5A and 5B; and FIG. 5F is a
cross sectional view along line F-F of the view of FIG. 5E.
[0023] FIGS. 6A to 6E are views of the venous line clamp.
[0024] FIGS. 7A to 7C are views of the venous reservoir
bracket/mount
[0025] FIGS. 8A to 8E are views of the oxygenator
mount/interface.
[0026] FIGS. 9A to 9F are views of the tubing clips.
[0027] FIGS. 10A to 10D are views of the cartridge cam locks and
tabs.
[0028] FIG. 11 is a block diagram of an alternative embodiment
wherein the venous reservoir is connected to a vacuum source for
use in vacuum assisted drainage procedures.
[0029] FIG. 12 is a functional diagram of the continuous level
sensor used to measure fluid level in the venous reservoir.
[0030] FIG. 13 is a front perspective view of cartridge 120.
[0031] FIG. 14 is a front plan view of cartridge 120.
[0032] FIGS. 15 and 16 are right and left side views, respectively,
of cartridge 120.
[0033] FIGS. 17 and 18 are top and bottom views, respectively, of
cartridge 120.
[0034] FIGS. 19A and 19B are back plan and back perspective views,
respectively, of cartridge 120.
[0035] FIG. 20A is a cross-sectional view of cartridge 120 taken
along line A-A of FIG. 19A.
[0036] FIG. 20B is an enlarged view of detail B of FIG. 20A.
[0037] FIG. 21 is a cross-sectional view of cartridge 120 taken
along line BB of FIG. 19A.
[0038] FIG. 22 is a back plan view of cartridge 120 with the
flexible back layer removed.
[0039] FIGS. 23A, 23B, 24A and 24B are partial views of a valve
station in cartridge 120.
[0040] FIG. 25 is a block diagram of the system architecture of the
blood perfusion system of the present invention.
[0041] FIG. 26 illustrates a schematic block diagram for the gas
circuit shown in FIG. 25.
[0042] FIGS. 27 to 33 illustrate various operational examples of
one embodiment of the system user interface 50. In particular, FIG.
27 illustrates the three display regions of display 54 of the user
interface.
[0043] FIGS. 28A-28F illustrate a variety of alarm and status
messages displayed in the first region of display 54.
[0044] FIG. 29 illustrates information sets displayed in the second
region of display 54.
[0045] FIGS. 30A-30L illustrate various context-driven information
sets and corresponding context-driven user control options
displayed in the third region of display 54.
[0046] FIGS. 31A-31F, FIGS. 32A-32E and FIGS. 33A-33F illustrate
various features of context-driven portion 243.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0047] The present invention is an integrated vertical perfusion
system. The main components of the system are a console which
houses the various pumps, control circuitry, sensors and other
nondisposable hardware, and a disposable assembly which connects to
and interfaces with the console. The disposable assembly includes
all of the disposable components used in the extracorporeal blood
circuit including, for example, a venous reservoir, a blood
oxygenator, a heat exchanger and an arterial blood filter, as well
as the tubing which connects the various components and which forms
the extracorporeal blood flow path. The disposable assembly also
includes a dedicated disposable cartridge which provides a primary
interface between the disposable assembly and the console. The
cartridge is provided with multiple fluid flow paths through which
the various fluid circuits of the system flow. Sensors which
interface with the fluid flow paths monitor certain characteristics
of the system such as pressure, temperature, fluid level and the
presence of bubbles in various locations in the system. These
characteristics provide an indication of whether the system is
operating within acceptable ranges. Should these monitored
characteristics deviate from acceptable ranges the system is
provided with feedback control features which cause the system to
automatically return pressure, flow, and fluid levels back to safe
and acceptable ranges. After any deviation, the system will alert
the user and go into a safe mode if necessary/appropriate. The
system will facilitate any required intervention by the user to
return to safe and acceptable ranges.
[0048] The perfusion system of the present invention will now be
described. For purposes of clarity an overview of the system will
first be provided. Then the various components and features of the
system will be described including the disposable assembly and
component interface, the system control, the user interface and an
operational summary of the perfusion system.
[0049] I. Perfusion System Overview
[0050] FIG. 1 illustrates a perfusion system 1 for use during
cardiopulmonary bypass surgery. The system comprises one embodiment
of various aspects of the present invention. Other applications and
embodiments of the inventive aspects will be apparent to those
skilled in the art.
[0051] The system 1 comprises a console or control unit 10 and a
disposable assembly 100. Disposable assembly 100 is best seen in
FIG. 2A which shows the disposable assembly prior to attachment to
control unit 10. In the illustrated embodiment, control unit 10 is
"left-handed," thereby permitting placement in an operating room so
that it allows a user (e.g., perfusionist) to visually monitor the
disposable assembly 100 when interfaced with control unit 10 during
operations, and to readily maintain a direct line-of-sight with a
head surgeon who is located in a sterile surgical field surrounding
a patient table (not shown). In this regard, and by way of example
only, control unit 10 is provided with wheels 5 and may be oriented
at an angle relative to the patient table, as desired. As will be
appreciated, control unit 10 may also be designed to be
"right-handed" or universal.
[0052] Control unit 10 includes various sensors and mounting
hardware for supportably receiving and/or operatively interfacing
with disposable assembly 100. More particularly, an upper component
interface plate 12 shown in FIG. 4 includes a cartridge interface
region 20 for receiving a cartridge 120 which forms a part of
disposable assembly 100. The cartridge interface region 20 includes
various sensors for monitoring parameters of fluid flowing through
the cartridge 120 during use as will be explained in more detail
hereafter. Further, control unit 10 includes additional sensors for
monitoring fluid parameters and various valves for controlling the
flow of fluid through disposable assembly 100.
[0053] Control unit 10 includes a plurality of vertically "stacked"
roller pump assemblies 31-36. Each pump assembly comprises a
rotatable control knob 31a-36a and a pump information display
3lb-36b, respectively.
[0054] The control unit 10 further includes one or more embedded
processor(s) and a user interface 50 having a main display 54, user
control knob 52, and a back up display 55. User interface 50 may be
incorporated into the main housing of control unit 10 or may be
provided in a separate housing 51 that it can be selectively
interconnected at a desired height and angular orientation relative
to an outboard pole 11 or other pole or mounting bracket located in
a desired position on control unit 10 such as shown in FIG. 1. As
will be further described, main display 54 and backup display 55 of
user interface 50 may be provided with various graphic user
interface (GUI) features, including touch-screen capabilities,
which together with user control knob 52 may be selectively
employed with the embedded processor(s) to establish/modify various
settings for monitoring and controlling various parameters in a
cardiopulmonary bypass procedure.
[0055] In general, set-up of the system 1 entails removal of
disposable assembly 100 from sterile packaging, e.g., a disposable
tray, and positioning of the various components of the disposable
assembly 100 relative to corresponding interfacing components of
control unit 10 as will be discussed in more detail hereafter. In
general, three primary fluid flow circuits are defined by the
disposable assembly 100: a venous circuit (i.e., for receiving
venous blood from a patient), an arterial circuit (i.e., for
returning oxygenated blood to a patient) and a cardioplegia circuit
(i.e., for delivery of cardioplegia to a patient). The arterial and
venous circuits may be combinatively referred to as the
arterial-venous, or "AV" circuit. Secondary circuits defined by
disposable assembly 100 include two suction circuits (i.e., for
selective suctioning of fluids from a patient by medical
personnel), and a vent circuit (i.e., for venting accumulated blood
or fluid from a patient's heart or vasculature). Another circuit
comprising a fluid management or priming circuit is used prior to
bypass to prime disposable assembly 100. As will be further
described, for flow control purposes through the fluid circuits,
positioning of the disposable assembly 100 on control unit 10
includes the placement of various looped tubing lines within pump
assemblies 31-36 and positioning of various tubing lines into
various valve assemblies on control unit 10.
[0056] Additionally, for monitoring various parameters within the
fluid circuits, the cartridge 120 and various tubing lines and
other components of disposable assembly 100 are positioned in
operative relationship to various pressure, temperature, bubble,
fluid level, hematocrit, oxygen saturation and other sensors
included in control unit 10. Further, an oxygenation device and one
or more heat exchangers included within disposable assembly 100 are
connected to gas and/or fluid inlet/outlet ports on control unit
10. After initial connections are made between the disposable
assemblies and control unit 10, the various fluid circuits defined
by the disposable assembly 100 are primed (i.e., filled with liquid
to remove air), according to predetermined protocols. Thereafter,
various tubing lines may be interconnected to a patient to provide
for the flow of fluids to/from the patient and disposable assembly
100.
[0057] II. Disposable Assembly
[0058] One embodiment of the disposable assembly 100 is shown in
FIGS. 2A and 2B. Disposable assembly 100 comprises various
extracorporeal blood circuit components interconnected by tubing to
create a blood flow path. FIG. 2A is a view of disposable assembly
100 before it is interfaced with control unit 10. FIG. 2B is
similar to FIG. 2A except that the tubing has been removed to more
clearly show the disposable components of the assembly. These
disposable components include disposable cartridge 120, venous
entry module 108, pre-bypass filter 168, venous blood reservoir
106, a combined oxygenator and heat exchanger 112, an arterial
blood filter 118 and tubing clips 111a-111f. Note that although the
oxygenator and heat exchanger are shown as an integrated unit,
separate devices could be used as is known in the art. The venous
entry module 108, cartridge 120 and tubing clips 111 are unique to
the perfusion system of the present invention and are discussed in
more detail hereafter.
[0059] III. Hardware Interface and Mounting Assemblies
[0060] Control unit 10 is provided with various structural elements
including line clamps, sensors and mounting brackets for
interfacing with components of disposable assembly 100. Many of
those sensors and interfacing structures are located on upper
component interface plate 12 as seen in FIG. 4. Interface plate 12
includes a cardioplegia-valve tubing block 195. Tubing block 195
includes a cardioplegia air bubble sensor 158, a cardioplegia
temperature sensor 153 and a motorized cardioplegia line valve 96.
Arterial valve tubing block 196 includes an arterial line air
bubble sensor 126, arterial temperature sensor 88,and a motorized
arterial patient line valve 92. Venous entry module mounting
bracket 550 includes oxygen saturation-hematocrit standardization
surface 83,oxygen saturation-hematocrit optical sensor 85 and a
venous temperature sensor 81. Interface plate 12 includes a
motorized pre-bypass filter valve 95 positioned above venous line
clamp 46 and pre-bypass filter mount 70. Located at the bottom
portion of plate 12 is an arterial filter mounting arm 760.
[0061] Upper component interface plate 12 includes a disposable
cartridge interface region 20. Interface region 20 includes those
components of control unit 10 which interface directly with
cartridge 120. Cartridge mounting assembly 21 is used to secure the
cartridge to region 20 in a manner discussed hereafter with regards
to FIGS. 10A-10D. Region 20 includes numerous pressure sensors for
sensing line pressure in various circuit locations. These sensors
include venous reservoir pressure sensor 89, first suction pump
pressure sensor 40, second suction pump pressure sensor 42, vent
pump pressure sensor 44, arterial line pressure sensor 14, and
cardioplegia line pressure sensor 18. Each of these pressure
sensors function in the same manner except that the sensors in the
suction circuits sense negative pressure. Each sensor includes a
load cell in control unit 10 and a load cell stem or cylinder
magnetically coupled thereto (not shown). The load cell stem is
aligned with the cartridge at the location pressure is to be
sensed. Pressure affects the vinyl backing of the cartridge causing
a force to be exerted against the load cell stem. This force is
converted to an electrical signal by the load cell. This electrical
signal is then converted to a pressure by a microprocessor. An
example of such a pressure sensor is described in U.S. Pat. No.
5,676,644 (Toavs et al.) which is incorporated herein by
reference.
[0062] A plurality of solenoid valve plungers are also included
within region 20. These valve plungers interface with complimentary
valve structures within cartridge 120 to open and close valves in
various fluid circuits within cartridge 120. These valve assemblies
include cardioplegia bubble trap purge valve 404, vent pump to
sequestration reservoir valve 402, vent pump to venous reservoir
valve 403, low flow purge valve 405, high flow purge valve 406 and
sequestration reservoir drain valve 401. Additional valve
assemblies could be included. For example, valve assemblies could
be included from the suction pump to sequestration reservoir and/or
suction pump to venous reservoir (not shown).
[0063] Cartridge interface region 20 includes several components
which interface directly with a sequestration reservoir located
within cartridge 120. First and second sequestration level sensors
320 and 322 are used to monitor the fluid level in the
sequestration reservoir. A defoamer push bar 790 is used to apply
pressure to a defoamer within the sequestration reservoir to ensure
that fluid which enters the sequestration reservoir is caused to
pass through the defoamer. Means is provided in control unit 10 for
bringing the cartridge 120 into automatic operative engagement with
the various components in interface region 20 by advancing such
components through plate 12 into contact with the cartridge.
[0064] At the upper portion of cartridge interface region 20 are
motorized priming solution (or other solution) bag line valves 98
and cardioplegia crystalloid bag line valves 99. Water connections
147a and 147b are provided for connecting to a cardioplegia heat
exchanger. Water connections 147a and 147b are designed to mate
with ports 149a and 149b on cardioplegia heat exchanger 148 in a
manner similar to that which will be described hereafter with
respect to the water connections made to heat exchanger 505 shown
in FIGS. 8A-8E
[0065] Control unit 10 includes additional structural elements for
interfacing with disposable assembly 100. For example, the
structure of the venous entry module 108 and the mounting bracket
with which it is attached to control unit 10 are shown in FIGS.
5A-5F. The structure and operation of the venous line clamps 46 and
the mounting bracket for the pre-bypass filter 168 are shown in
FIGS. 6A-6E. The mounting bracket for the venous reservoir is shown
in FIGS. 7A-7B. The mounting hardware for the combined
oxygenator/heat exchanger 112 is shown in FIGS. 8A-8E. The mounting
hardware for the arterial filter 118 is shown in FIGS. 1 and 4. The
manner in which cartridge 120 is mounted and interfaced with
control unit 10 is shown in FIGS. 10A-10D. Finally, the structure
of tubing clamps 111a-111f is shown in FIGS. 9A-9F. A discussion of
these components and their mounting and interface with control unit
10 follows.
[0066] Although certain sensors, valves, etc., are packaged
together in blocks in this embodiment, they could be provided as
individual components or combined together in any variety of
integrated assemblies or in one common assembly.
[0067] 1. Venous Entry Module
[0068] The venous entry module 108 is a unique component which
allows multiple functions to be accomplished within a single
circuit component. The structure and features of the venous entry
module can best be understood with reference to FIGS. 5A and 5B.
The manner in which the venous entry module is mounted and
interfaced with control unit 10 is shown in FIGS. 5C-5F.
[0069] With particular reference to FIGS. 5A and 5B which are
perspective views of the top and bottom portions of the venous
entry module it can be seen that the venous entry module has inlet
and outlet ports 530 and 532, respectively, which may be barbed.
Housing 534 defines a lumen or conduit between the inlet and outlet
ports which comprises the primary flow passage for venous blood
entering reservoir 106. A secondary flow port 536 is provided
allowing the flow through the venous entry module to be diverted
through the pre-bypass filter during priming of the disposable
assembly 100 as described more fully hereafter. Housing 534 is also
provided with sampling/infusion fluid addition/removal ports 538,
540 and 542. These ports are connected to stopcock valves 539, 541
and 543, respectively. These valves allow access to the venous line
for the addition of medication or fluids or removal of blood. For
example, these valves allow a venous blood sample to be taken,
allow fluids or drugs to be infused during the bypass procedure,
allow blood to be removed for pre-donation sequestration prior to
the procedure, and allow fluid to be added at some later point in
the procedure. Mounting tabs 544 and 546 on the side portions of
housing 534 are located and sized to provide a handhold for easy
loading and to ensure proper positioning of the venous entry module
in upper and lower mounting clips 548 and 552 of mounting bracket
550 as shown in FIGS. 5C and 5D.
[0070] As shown in FIGS. 5B and 5C, housing 534 includes an oxygen
saturation-hematocrit sensing window 554 and a temperature sensing
window 556. Window 554 is aligned with optical sensor 85 on
mounting bracket 550 so that hematocrit and oxygen saturation of
the venous blood flowing through the venous entry module can be
measured. The manner of sensing oxygen saturation-hematocrit is
described in detail in U.S. Pat. No. 5,356,593 (Heiberger et al.),
the entirety of which is incorporated herein by reference. Window
556 is aligned with infrared temperature sensor 81 to allow the
temperature of the venous blood to be monitored. This temperature
sensor is of conventional design and need not be described in
detail herein.
[0071] As best seen in FIGS. 5C and 5D the venous entry module is
held in place in clips 548 and 552 by arms 548a, 548b, 552a and
552b. FIG. 5E is a front view of venous entry module 108 in bracket
550. FIG. 5F is a sectional view taken along line F-F of FIG. 5E.
The distance between the adjacent arms is slightly less than the
outer dimension of the portion of the venous entry module
positioned between the arms. Therefore, the venous entry module is
snap fit into bracket 550 and held by the adjacent arms. Bracket
550 includes a block 558 having a sliding portion 560. Sliding
portion 560 is spring loaded by virtue of spring 559 acting on
stationary surface 561. Portion 560 includes a lower surface to
which is mounted standardization surface 83. During power up prior
to insertion of the venous entry module standardization surface 83
is positioned over sensor 85 to allow the sensor to automatically
standardize at power up. The light reflects off the standardization
surface which allows the device to standardize. As the venous entry
module is installed, the sliding portion moves out of the way so
that window 554 is positioned over sensor 85.
[0072] 2. Pre-Bypass Filter and Venous Line Clamp
[0073] As noted above, the component interface region includes a
venous line clamp assembly (VLC) 46 for receiving tubing line 104
therewithin and a bracket for mounting the pre-bypass filter to
control unit 10. The tubing size of the portion of line 104 between
VLC 46 and venous reservoir 108 is preferably larger in diameter
than the portion from the patient to VLC 46. For example, the
portion from the patient to VLC 46 may be a one-half inch line
while the portion from the VLC to the venous reservoir may be
five-eighth inch. In general, VLC 46 is provided to control the
passage of venous blood from a patient to the venous reservoir 106
during bypass procedures. FIGS. 6A-6E illustrate one embodiment of
a VLC 46, which comprises a housing 71 for receiving venous tubing
line 104 through a slot 72 provided in the housing 71. A lid 73 may
be hingedly interconnected to housing 71. Housing 71 includes a
bracket 70 into which pre-bypass filter 168 may be secured. Bracket
70 is substantially cylindrically shaped and forms slightly more
than 180.degree. of the circumference of a cylinder. The dimensions
of this cylindrical configuration are chosen so that the pre-bypass
filter can be snap fit into the bracket and held without further
attachment. A lid latch 74 may be interconnected to housing 71,
wherein a lip portion 74a is adapted for selectively retaining lid
73 in a closed condition relative to housing 71. As will be
appreciated, when lid 73 is in such a closed condition, a venous
tubing line 104 may be retained within the slot 72 of the housing
71.
[0074] The VLC 46 further includes a stepper motor 75. One end of a
lead screw 76 may be positioned in the stepper motor 75 and the
other end of lead screw 76 may be interconnected to a plunger 77,
wherein the stepper motor 75 may be selectively operated for
advancement/retraction of plunger 77. The plunger 77 is sized and
oriented to pass through an opening in the back of the housing 71,
wherein selective operation of the stepper motor 75 allows the
plunger 77 to be advanced across/retracted from the slot 72 passing
through housing 71. By virtue of such selective ability to position
plunger 77, the VLC 46 provides for the selective occlusion of a
tubing line 104 positioned within the slot 72 housing 71. More
particularly, when tubing line 104 is positioned through slot 72
and lid 73 is secured in a closed position by the latch 74, actual
advancement of plunger 77 by stepper motor 75 will cause the tubing
line 104 to be pinched between plunger 77 and lid 73 so as to
occlude the tubing line 104 to a desired, selective extent. The lid
73 can be opened at anytime, anywhere from the venous line clamp
being fully open or closed. This allows removal of the venous line
in the event of a failure so it can be manually clamped. The lid 73
is also clear so the user can verify venous line clamp actuation
and open/closed status. In order to facilitate calibration at VLC
46 (e.g., to accommodate varying wall thickness in tubing line
104), VLC 46 may further include an optical encoder 78, wherein a
calibration procedure may be carried out to determine the desired
positioning of lead screw 76 for a given procedure.
[0075] 3. Venous Reservoir
[0076] The mounting assembly of venous reservoir 106 is shown in
FIGS. 7A and 7B. FIG. 7A is a perspective view of reservoir
mounting bracket 602 spaced from reservoir 106 prior to reservoir
106 being inserted into bracket 602. FIG. 7B is a perspective view
of reservoir 106 attached to mounting bracket 602. For purposes of
illustrating clearly the mounting structure mounting bracket 602 is
shown detached from control unit 10. During use it will be
understood that bracket 602 is affixed to control unit 10 in the
position shown in FIG. 1.
[0077] As shown in FIGS. 7A and 7B mounting bracket 602 includes
flexible arms 604 and 606. The arms are provided with grooves 606a
and 604a which are shaped to received the circumferential edge 107a
of a lid 107 at the top of reservoir 106. Reservoir 106 is mounted
by sliding edge 107a into grooves 604a and 606a. Flexible arms 604
and 606 are slightly curved and extend more than 180.degree. around
edge 107a so that reservoir 106 is held in a snap fit configuration
by arms 604 and 606.
[0078] 4. Oxygenator/Heat Exchanger
[0079] The mounting assembly for the combined oxygenator/heat
exchanger is shown in FIGS. 8A-8E. FIG. 8A is a perspective view of
oxygenator/heat exchanger 112 separated from mounting bracket 500.
FIG. 8B is a back perspective view of oxygenator/heat exchanger 112
showing the location of the various gas and water inlet and outlet
ports. FIG. 8C is a front view of mounting bracket 500 showing the
location of gas and water connections. FIG. 8D is a front view of
the oxygenator/heat exchanger 112 mounted on bracket 500 and FIG.
8E is a cross-sectional view taken along line E-E of FIG. 8D.
[0080] In the embodiment shown in FIGS. 8A and 8B mounting assembly
500 includes a lower portion 501 which is configured to receive the
heat exchanger. Portion 501 has a heat exchanger receiving slot 502
with lower grooves 502a and 502b. Between grooves 502a and 502b is
a ledge 503 for retaining the heat exchanger. Slotted side portions
504a and 504b are configured to receive heat exchanger mounting
tabs 505a and 505b. Thus, to mount oxygenator/heat exchanger 112 on
lower portion 501 the heat exchanger 505 is inserted in slot 502
with heat exchangers tabs 505a and 505b above slotted side portions
504a and 504b. The heat exchanger is then moved in a downward
direction so that the heat exchanger tabs mounting 505a and 505b
are received in slots 504a and 504b, respectively, and so that
retaining ledge 503 is positioned between the heat exchanger and
the oxygenator.
[0081] As best seen in FIG. 8C mounting assembly 500 includes gas
fittings 508a and 508b for providing oxygen-containing gas to the
oxygenator and removing carbon dioxide therefrom. Additionally
fittings 509a and 509b are provided for circulating heating/cooling
fluid through the heat exchanger. Motorized oxygenator vent line
valve 507 is provided to receive vent line 105 connected between
the oxygenator and venous reservoir. Loading of the vent line into
the vent line valve is facilitated by vent line loading element 506
which is slotted to receive and route the vent line through slots
507a and 507b of valve 507. Valve 507 includes a roller 525
eccentrically mounted on a rotating member (not shown) that, when
rotated, causes the roller to pinch the tubing to occlude or
partially occlude flow.
[0082] Fittings 508a, 508b, 509a and 509b are tapered at their end
portions and have O-rings 512, 513, 514 and 515 disposed
thereabout. The tapered ends of fittings 508a and 508b are designed
to sealingly engage gas inlet and outlet ports 518a and 518b on the
oxygenator while tapered fittings 509a and 509b are designed to
sealingly engage water inlet and outlet ports 519a and 519b of the
heat exchanger. Mounting assembly 500 is designed to automatically
engage the tapered fittings with the corresponding ports of the
oxygenator and heat exchanger. Mounting assembly 500 includes a
stationary face plate 510 and a moveable carriage member 511. The
carriage member may be advanced or retracted with respect to face
plate 510 by operation of a stepper motor 516 acting on a lead
screw 517 as shown in FIGS. 8A and 8E.
[0083] The carriage member rides on guide rods (not shown) which
are pressed into the face place. Forward and reverse limit switches
(not shown) are used to indicate when the carriage member is
forward or fully retracted. The carriage member must be retracted
to load an oxygenator into the bracket.
[0084] As best seen in FIG. 8E, the water and gas fittings are
spring loaded along the fitting axes and able to move freely
perpendicular to the axes. All of the fitting axes are parallel to
allow them all to engage the oxygenator or heat exchanger in a
single motion. Each fitting is mounted in a flanged bushing, such
as 520a, 520b, and 520c. The inside diameter of the bushing is
larger than the outside diameter of the fitting at the inserted
section, so that the fitting can move freely inside the
bushing.
[0085] Axial motion of the fitting relative to the bushing is
prevented in one direction by a flange on the fitting (i.e., 521a,
521b, 521c) which mates with a flange on the bushing. Motion in the
opposite direction is limited by a retaining ring (not shown)
attached to the fitting which collides with the back surface of the
bushing.
[0086] The fitting assembly is spring loaded towards the mating
port with a compression spring (i.e., 522a, 522b, 522c). The
compression spring exerts a force on the back side of the bushing
flange. The opposite end of the spring pushes against a surface of
the fitting base which is fixedly attached to the carriage
member.
[0087] The heat exchanger water fittings are machined from a single
piece of material. However, the gas supply fitting and scavenge
line fitting are made from an assembly of a machined fitting piece
and a standard pipe nipple. The pipe nipple rides inside the
flanged bushing. The back portion of the gas fitting rides against
the flange face of the flanged bushing.
[0088] The gas and water fittings are connected to the carriage
member so that they are caused to advance or retract by movement of
the carriage member. Thus, once the heat exchanger has been mounted
on lower portion 501 the connections for water and gas may be
automatically made by advancing the carriage so that the fittings
are caused to engage with the corresponding ports on the oxygenator
and heat exchanger.
[0089] 5. Arterial Blood Filter
[0090] The manner in which the arterial blood filter 118 is mounted
and interfaced with control unit 10 can best be understood with
reference to FIGS. 1 and 4. Blood filter 118 held by mounting arm
760. Arm 760 extends from a lower portion of upper component
mounting plate 12. Arm 760 includes a first straight portion 761
and a second flexible curved portion 762. Curved portion 762 is
provided with a groove 762a which is sized to accommodate an
outwardly extending lip on the cover of filter 118. Curved portion
762 is substantially semicircular and extends slightly past
180.degree.. Therefore, the outwardly extending lip may be snapped
into place in groove 762a so that the arterial filter is held
securely by arm 760.
[0091] A rotating assembly means 763 is activated during the
priming of disposable assembly 100 to cause arm 760 along with
arterial filter 118 to rotate 180.degree.. This facilitates removal
of air bubbles from filter 118. By flipping the filter 180.degree.
during an automated priming procedure, even though priming fluid
follows an antegrade path through the filter from the inlet to the
outlet the direction is from bottom to top. In conventional priming
techniques retrograde flow of priming fluid from outlet to inlet is
required in order to get bottom to top flow. In conventional
systems, this requires extra set up for priming of the filter and a
bypass line with extra ports.
[0092] In order to enhance the efficiency of bubble removal during
priming portion 761 is angled about 221/2.degree. from the
horizontal and portion 762 is angled about 45.degree. from the
horizontal to allow air to rise to the arterial filter purge
outlet. This results in filter 118 being held at an angle during
bypass as shown in FIG. 1. However, during the priming procedure
discussed in more detail hereafter, when arm 760 is rotated
180.degree. the angled portions 761 and 762 cause filter 118 to be
held such that its longitudinal axis is perpendicular to an
intersecting horizontal plane. This allows priming fluid (and
bubbles) to flow vertically and upwardly through the filter from
the inlet to the outlet which lessens the chance of bubbles being
trapped within the filter during priming.
[0093] 6. Tubing Clips
[0094] As indicated hereinabove, clips 111a-fmay be provided to
define predetermined U-shaped configurations for tubing loops 110,
132, 140, 178, 180, and 190, respectively. One embodiment that may
be employed for tubing clips 111a-f is illustrated in FIGS. 9A-9F.
As shown, the exemplary tubing clip 700 may include a central body
member 702 having two tubing connector wings 704 extending from
opposing sides of the central body member 702. Each of the tubing
connector wings 704 may define a longitudinally-extending J-shaped
channel for receiving a tubing length therethrough. One or more
wedge-shaped members 706 may be disposed within each of the
J-shaped channels of the tubing connector wings 704 for retaining
tubing positioned through the channels. Alternatively, the tubing
may be glued within the channels to prevent movement. The tubing
connector wings 704 may be oriented at an angle relative to the
main body member 702 so that the center axis of each of the
channels are angled. This allows the tubing entering the pump to
conform to the pump raceway. This allows a desired tubing loop
configuration to be formed when the clip is applied to the tubing
thus facilitating the loading of the tubing loop into one of the
pump assemblies 3136. The central body member 702 may include a
projecting grip tab 708 contoured in an hourglass configuration to
facilitate handling and placement of the clip 700 in a pump
assembly. In the latter regard, the central body member may include
a hollow bottom portion to matingly fit over a projection provided
on a pump assembly. The clip 700 may be integrally formed (e.g.,
via molding, etc.). The tubing clips may be color coded to match
corresponding color coding on control unit 10 to ensure correct
placement of the pump loops.
[0095] 7. Cartridge
[0096] The perfusion cartridge 120 allows for automation of the
perfusion system because the compact and standardized format of the
positioning of the passageways in the cartridge 120 allows computer
controlled sensors and actuators to interact with the cartridge
120. It is important that the interface between cartridge 120 and
control unit 10 be precise and secure. The manner in which
cartridge 120 is mounted on control unit 10 is shown in FIGS. 10A
and 10D. In this regard, cartridge mounting assembly 21 secures the
perfusion cartridge 120, as shown in FIG. 10A, to cartridge
interface region 20. Interface region 20 contains temperature
and/or pressure sensors located to interface mount with sensor
stations on the cartridge 120. Region 20 also contains valve
plungers positioned to interface with valve stations on the
cartridge.
[0097] FIG. 10A shows cartridge 120 contained within mounting
assembly 21. Although interface region 20 and mounting assembly 21
are part of upper component interface plate 12 for purposes of
illustration and to facilitate an understanding of the mounting of
cartridge 120 only mounting assembly 21, interface region 20 and
cartridge 120 are shown in FIGS. 10A-10A-D.
[0098] FIG. 10C shows cartridge 120 spaced apart from mounting
assembly 21. To facilitate mounting cartridge 120 is provided with
mounting tabs 121. Assembly 21 has openings 115 which expose slots
117 which are sized to securely accept tabs 121 of cartridge 120.
To load cartridge 120 into mounting assembly 21 tabs 121 are
aligned with openings 115. The cartridge is then moved in the
direction of interface region 20 until the tabs 121 align with
slots 117. Once so aligned the cartridge is moved downward in the
direction of arrow 131 (FIG. 10D). This secures each of the tabs in
corresponding slots and holds cartridge 120 against interface
region 20.
[0099] To insure that cartridge 120 is properly positioned with
respect to interface region 20 and that it maintains the proper
position during the bypass procedure a positioning mechanism is
provided. As shown in FIG. 10B, which is an enlarged portion of
FIG. 10A, motorized cardioplegia crystalloid valves 99 include an
angled bottom surface 124. When cartridge 120 is loaded into
mounting assembly 21 valves 99 are retracted so that they do not
extend beyond the surface of interface region 20. Once cartridge
120 has been loaded into mounting assembly 21 the continuing set up
of the system results in valves 99 being advanced past the surface
of interface region 20 until they reach the position shown in FIG.
10B. As the valves advance angled surface 124 abuts against surface
127 on cartridge 120 resulting in a downward pressure being exerted
on cartridge 120. This ensures that cartridge 120 is in its proper
position and that it does not move during the bypass procedure.
[0100] Valves 99 are roller valves similar in structure to valve
507 and include rollers 101 and slots 99a and 99b. Valves 98 are
roller valves similar to valves 99 although the specific structure
is not shown in FIG. 10B. The cartridge includes tubing retainers
102a-d which hold the crystalloid solution and priming lines in the
proper alignment for loading to valves 98 and 99.
[0101] IV. Functional Integration of Disposable Assembly and
Control Unit
[0102] FIGS. 3A and 3B are schematic diagrams of different
embodiments of the functional interface between disposable assembly
100 and control unit 10. The embodiment of FIG. 3A relates to the
functional interface of a system using the cartridge 120 as
disclosed in the drawing figures herein. The embodiment of FIG. 3B
relates to a version of the perfusion system using a cartridge
modified in a manner disclosed herein.
[0103] As shown in FIG. 3A, disposable assembly 100 includes a
number of tubing lines that either alone or in combination with the
integral passageways of cartridge 120 define a number of fluid
circuits. In particular, tubing line 104 extends from a cannula
assembly at a distal end (not shown) to a venous reservoir 106 via
a venous entry module 108. As previously described the venous entry
module includes sensing windows 554 and 556 which interface with
oxygen saturation-hematocrit sensor 85 and temperature sensor 81
located in cartridge interface region 20. These sensors can provide
feedback for use in various control circuits. For example, a user
can set alarm limits which provide an alarm if a low oxygen
saturation and/or hematocrit condition exists. Further, if oxygen
saturation is low the system can be set to automatically increase
the speed of the arterial blood pump 31 an incremental amount
and/or automatically adjust the gas blender to increase gas flow or
FiO.sub.2 concentration through the oxygenator, until the condition
is corrected. Additionally, when blood is detected as flowing
through the venous entry module by sensor 85 all pre-bypass
activity is automatically inhibited (i.e., pre-bypass filter valve
95 is closed so that flow through the pre-bypass filter is
discontinued). The venous entry module also allows pre-donation
blood to be collected for reinfusion to the patient at the end of
the procedure through a large bore stopcock 543 on the front of the
venous entry module. Pre-donation is the collection of a portion of
the patients blood, usually about one liter but is based on
calculating what the patient can give up without lowering the
hematocrit below some predetermined value, as the blood first comes
down the venous line. This blood is sequestered and usually
reinfused back into the patient at the end of the procedure.
[0104] For purposes hereof, all components upstream of oxygenator
112 collectively comprise the "venous circuit". During a
cardiopulmonary bypass procedure, tubing line 104 will transfer
venous blood from one or more of the large veins entering the heart
(e.g., the venae cava) or other veins of a patient to venous
reservoir 106. As described with respect to FIGS. 6A-6E, the flow
of venous blood though line 104 may be selectively regulated by a
venous line clamp (VLC) 46. Flow may also be regulated by using a
vacuum system interconnected to the venous reservoir 106 as
discussed hereafter with respect to FIG. 11, or a pump (not shown)
that regulates venous blood flow through line 104 upstream of the
venous reservoir 106. The VLC is an integral part in the automatic
control of the perfusion system. Once the bypass has been initiated
the VLC is automatically kept open when arterial pump 31 is
running. If pump 31 shuts down for any reason the VLC may
automatically be closed by the system control. The VLC may be
closed when the level sensor in the venous reservoir senses that
the reservoir is full. Additionally, the rate of flow of blood to
the venous reservoir can be controlled by the extent to which line
104 is occluded by the VLC. The control can be automatic such as a
system initiated response due to a high blood level condition being
sensed in the venous reservoir, or can be manual through user
settings at the user interface.
[0105] Tubing line 104 may be constructed from a clear, flexible
tubing to allow for selective occlusion by the VLC 46 and to
otherwise allow for visual inspection of fluid passage therethrough
by a user. In this regard, the VLC 46 may include a transparent lid
73.
[0106] Reservoir 106 may be of a hard shell or soft, plastic
construction, and may be partially transparent with volumetric
markings to facilitate visual monitoring of volume content by a
user during a bypass procedure. The reservoir 106 may include a gas
vent at a top end thereof to allow for the venting of any
accumulated gas. Alternatively, the reservoir may be sealed, and
may further include a top port for interconnection with a vacuum
source for optional use in vacuum assisted venous drainage
procedures. The vacuum source may comprise a vacuum pump (e.g.,
within control unit 10) or a regulator that may be selectively
interconnected with a facility vacuum line.
[0107] FIG. 11 shows an alternative embodiment where reservoir 106
is connected to a vacuum source for use in vacuum assisted drainage
procedures. In FIG. 11, vacuum line 721 is attached to the vacuum
port of venous reservoir 106, connecting the venous reservoir to
the vacuum system. The system comprises vacuum line 721
interconnected to float valve 722, hydrophobic filter 726,
electronic vacuum regulator 727, and to an external vacuum source
728. The float valve 722 automatically closes to prevent fluid from
entering the vacuum system in the event of a venous reservoir
overflow. The hydrophobic filter 726 also prevents fluid from
passing further into the vacuum system. The electronic vacuum
regulator 727 provides continuously adjustable control of the
vacuum level in the venous reservoir as measured by vacuum sensor
725, and as discussed hereafter, can be activated to provide level
control within the venous reservoir. Also incorporated in the
vacuum circuit are positive pressure relief valve 723 and excess
vacuum relief valve 724. These valves will automatically open if
required to provide additional control to prevent vacuum from
exceeding a predetermined upper or lower limit.
[0108] The venous reservoir can be provided with a level sensor 87
as will be described in more detail hereafter with respect to FIG.
12. The sensed level can be used to activate alarms at the user
interface indicative of, for example, full reservoir, empty
reservoir, and low level. The sensed level can also be used in the
closed loop feedback control of other parts of the perfusion system
which affect the level of blood in the reservoir. For example, the
sensed level can be used to control the fluid level in the
reservoir by controlling VLC occlusion, arterial pump speed or the
amount of vacuum if the reservoir is vacuum assisted in order to
maintain, increase or decrease the reservoir volume or level as
needed to transfer fluid back and forth to the patient or maintain
a safe reservoir level to prevent emptying.
[0109] A reservoir filter pressure sensor 89 is included in
integral passageway 164 in the embodiment of FIG. 3A. During bypass
if suctioned cardiotomy blood is routed to the venous reservoir the
reservoir filter can clog. This cardiotomy blood is gravity drained
from the sequestration reservoir and if the venous reservoir filter
becomes clogged, pressure can build. Sensor 89 senses the increased
pressure from a clogged filter and provides an alarm on user
interface 50. In the event of any alarm, the suction and vent pumps
may be stopped and/or valve 401 may be automatically closed, and/or
valve 98 may be automatically closed.
[0110] Connected to the bottom end of reservoir 106 is an
interconnect tubing line 110 which carries blood from venous
reservoir 106 to an oxygenator 112. Although referred to herein as
oxygenator 112 it should be understood that the oxygenator may
include an integral heat exchanger. As will be further described,
the flow of blood through the interconnect tubing line 110 is
selectively regulated by arterial pump 31. Tubing line 110 may
include a clip 111a as described with respect to FIGS. 9A-9F for
retaining a predetermined tubing length in a predetermined u-shaped
configuration for ready interface with the arterial pump assembly
31. Further, such clip may be color-coded (e.g., red for arterial)
and configured to facilitate ready pump interface identification
and clip placement during loading procedures.
[0111] Pressure sensor 84 may be provided to sense the pressure in
tubing loop 110 downstream of the arterial pump 31 and upstream of
the oxygenator device 112. In this regard, the monitored pressure
may be compared to predetermined minimum and maximum values. A
monitored pressure below the predetermined minimum value indicates
that pump 31 may not be occluding tubing loop 110 as desired or may
not otherwise be operating at a rate set by use of control 31a,
resulting in an alarm/indication at interface 50. A monitored
pressure that exceeds the predetermined maximum value indicates
that the arterial circuit downstream of sensor 84 may be
undesirably occluded (e.g., partially or fully), and may effect
automated stoppage or slow down of pump 31 and result in an
alarm/indication at interface 50.
[0112] Oxygenation device 112 is fluidly interconnected at its
outlet port to outlet tubing line 116 which is connected to the
inlet of arterial filter 118. Outlet tubing line 116 may be
retainably positioned relative to a bubble sensor 114 located on
control unit 10. Bubble sensor 114 serves several functions. First,
if bubbles are detected an alarm may be activated at user interface
50. Second, detected bubbles may cause an auto air shunt feature to
be activated as described in more detail hereafter.
[0113] The embodiment of FIG. 3A includes an oxygenator vent tubing
line 105 from the oxygenator to the venous reservoir. Tubing line
105 passes through oxygenator vent valve 507. Vent valve 507 has
several functions. First, it is automatically opened during priming
to remove air from the oxygenator and is closed after a
predetermined time. Second, it can be manually opened by the user
during bypass if, for example, the venous reservoir emptied causing
air to enter the system necessitating that the system be reprimed
or, repriming the oxygenator after oxygenator replacement.
[0114] Arterial filter 118 is designed to filter particles greater
than a predetermined size (e.g., having a maximum cross-sectional
thickness greater than 50 microns), and is fluidly interconnected
to outlet tubing lines 122, 128, and 119a. Outlet tubing line 122
is provided for the return of oxygenated blood to a patient via a
cannula assembly at a distal end (not shown). Tubing line 122 may
be retainably positioned in a bubble sensor 126 located on control
unit 10. If bubbles are sensed by sensor 126 an alarm at user
interface 50 will be activated. Additionally, a signal will be fed
to the control unit 10 which will cause the arterial pump 31 to
stop. The system is designed so that anytime the arterial pump is
stopped, purge valves 405 and 406 and the arterial patient valve 92
may be closed. It should be noted that anytime a detected alarm
condition causes the system to automatically stop a pump or close a
valve that action can be overridden by the user at the user
interface.
[0115] In the event a user would like to draw a sample of the blood
passing through arterial filter 118, a user may open a stopcock
valve 310 or 311 provided on cartridge 120. If the sample is to be
taken from valve 310, either valves 405 or 406 must be open. For
purposes of hemoconcentration, a user may also manually open valve
310 or 311 provided on cartridge 120 to provide for the flow of
arterial blood therethrough. In this regard, the user may provide a
separate hemoconcentrator unit (not shown) having inlet tubing
connected to stopcock valve 310 or 311 and outlet tubing
interconnected to a transfer bag (not shown) or interconnected to
an inlet port provided at venous entry module 108 or venous
reservoir 106.
[0116] For purposes hereof, the noted components downstream from
oxygenator 112 through outlet tubing line 122 collectively,
comprise the "arterial circuit". To facilitate priming procedures,
tubing lines 104 and 122 may be initially fluidly connected via a
connector 175 which is removed after priming and prior to cannula
placement.
[0117] In order to monitor the temperature of the oxygenated blood
returned to a patient, the upper component interface plate 12 may
also include temperature sensor 88 located in tubing line 122.
Alternatively, the sensor 88 may be positioned for sensing
temperatures at arterial filter 118. The monitored temperature of
returned blood is compared to predetermined minimum/maximum range
values, wherein an alarm or other indication (e.g., an indication
of potential responsive action) can be provided at user interface
50 upon the detection of out-of-range conditions. Similarly, valve
assembly 92 may be included to receive tubing line 122 downstream
of the bubble sensor 126, and may be selectively and automatically
opened/closed to control the flow of oxygenated blood through
tubing line 122, including for example, closure both during pre- or
post-bypass procedures and when bubble sensor 126 detects gaseous
bubbles in the oxygenated blood during bypass procedures.
[0118] Tubing lines 119a and 119b are provided for fluid flow from
arterial filter 118 to cartridge 120, and from cartridge 120 to
reservoir 106, respectively. Adjoining integral passageways 309a
and 309b are provided in cartridge 120 to selectively receive fluid
flowing through tubing line 119a. In order to control the flow of
fluid through passageways 309a and 309b, cartridge interface region
20 includes interface valve assemblies 405 and 406. When opened,
valve 405 provides for a relatively low flow rate through
passageway 309b. Valve 406 provides for a relatively high flow rate
through passageway 309a when valve 406 is open. During bypass
procedures, valves 405 and 406 typically remain open and closed,
respectively; provided pressure sensor 14 senses a pressure greater
than a predetermined minimum value. If a pressure lower than the
minimum value is sensed both valves 405 and 406 automatically close
in order to prevent air from being sucked from the venous reservoir
into the arterial filter. A user may selectively change these
states via user interface 50, as will be further described. In
order to purge air from tubing line 116 and arterial filter 118
(e.g., upon bubble sensing by bubble sensor 114), valve 92 may be
closed (e.g., automatically), and valves 405 and 406 may be opened
(e.g., automatically), wherein blood will flow through tubing line
119a, integrated passageway spurs 309a and 309b, and tubing line
119b into venous reservoir 106 via an inlet port. Additionally, in
the event that air is detected in tubing line 122, valves 92 and 96
may be closed and valve 404 opened so as to cause blood to flow
retrograde from the patient through tubing line 122 through filter
118, flow tubing line 128, integral passageway 130 and ultimately
through integral passageways 164 and 308 for return to venous
reservoir 106 through line 129. It should be noted that valve 406
may be selectively opened for recirculation purposes or otherwise
by a user.
[0119] As noted, arterial filter 118 is also interconnected to
outlet tubing line 128, which in turn is interconnected with one
end of an integral passageway 130 defined within the cartridge 120
to provide the blood supply for the cardioplegia system.
[0120] Pressure sensor 14 is provided in cartridge interface region
20 for monitoring the fluid pressure within fluid passageway 130
and tubing lines 128 and 122 fluidly interconnected thereto. During
cardioplegia blood delivery via tubing line 128 and pump 35, the
monitored pressure may be compared to a predetermined value to
insure that an adequate blood delivery pressure is provided. If the
pressure falls below a predetermined minimum value, pump 35 may be
stopped and/or an alarm/indication may be provided at user
interface 50. Additionally, if the arterial blood circuit has
become occluded, automated stoppage of pump 31 may be provided and
an alarm/indication may be provided at user interface 50 if the
pressure exceeds a predetermined maximum value.
[0121] Tubing line 128, cartridge passageway 130 and tubing loop
132 are provided for the flow of blood therethrough for selective
downstream mixture with a heart-arresting solution (e.g., a
cardioplegic crystalloid solution) and/or a substrate enhancing
solution (e.g., nutritional solution) in an integral passageway 142
of cartridge 120. As will be further described, tubing loop 132
interfaces with a cardioplegia blood pump assembly 35 of component
interface region 12 to control mixture ratios. Tubing loop 132 may
include a clip 111b to establish the desired unshaped configuration
for the pump interface, and the clip may be color-coded (e.g., red)
to facilitate ready loading.
[0122] Disposable assembly 100 further includes one or more spiked
tubing lengths 133 for interconnection between one or more
corresponding bags 136 of a heart-arresting solution (e.g.,
crystalloid solution) and a fluid passageway 138 integrally defined
within cartridge 120. One or more substrate enhancing solutions
(not shown) may also be fluidly interconnected by spiked tubing
lengths 133 to the integral passageway 138 of cartridge 120. When
multiple bags 136 are provided they may contain solutions of
different concentration and/or ingredients. The user is able to
select the desired solution concentration by selecting at the user
interface which one of valves 99 is opened. The user is able to
select a volume or time bolus of solution and the opened valve 99
automatically closes when delivery is completed or interrupted such
as when one or more of pumps 31, 35 or 36 is stopped. The user is
also able to manually select and deliver the cardioplegia
solution.
[0123] Passageway 138 is interconnected to a tubing loop 140 that
flows heart-arresting or substrate enhancing solution out of and
back into the cartridge 120 and interfaces therebetween with a pump
assembly 36 on control unit 10 that regulates the flow rate through
the tubing loop 140. Tubing loop 140 may include a clip 111c to
establish the desired u-shaped configuration for pump interface,
and the clip 111c may be color-coded to facilitate loading.
[0124] Integral passageway 142 is also interconnected to the
above-mentioned tubing loop 132 for establishing a desired mixture
between the cardioplegic crystalloid solution and blood pumped into
the integral passageway 142. In this regard, it should be
appreciated that cardioplegia provided to a patient may comprise
predetermined (or dynamically adjusted) relative amounts of a
heart-arresting solution (crystalloid) and blood, and may
alternatively comprise only a heart-arresting solution
(crystalloid), or alternatively comprise only oxygenated blood.
[0125] In this regard, a tubing line 146 is provided for the
passage of a cardioplegia solution out of the cartridge 120,
through a cardioplegia heat exchanger 148 and a bubble trap 152,
and back into the cartridge 120. In an alternate arrangement, heat
exchanger 148 and/or bubble trap 152 may be integrated into
cartridge 120.
[0126] Of additional note, the embodiment of FIG. 3A includes a
stopcock valve 302 in fluid communication with the bubble trap 152
through which the cardioplegia mixture flows during operations. The
inclusion of stopcock valve 302 allows a user to selectively infuse
drugs into the cardioplegia mixture. Further, stopcock valve 302
may be selectively employed by a user for interconnection of an
auxiliary pressure sensor (i.e., monitor the cardioplegia pressure)
or it can be used to sample the cardioplegia solution or can be
connected to a hemoconcentrator (not shown). Relatedly, it is noted
that the cartridge 120 in the FIG. 3A embodiment also includes an
added integral passageway 308 that interfaces with a corresponding
valve assembly 404 provided in the cartridge interface region 20.
More particularly, valve 404 can be selectively opened/closed in
opposing or same relation to valve 96 in a number of situations.
For example, valve 96 may be closed and valve 404 opened during
priming so as to cause fluid flowing through integral passageway
150 to flow through integral passageway 308 and into integral
passageway 164. Additionally, during cardioplegia delivery, if a
user observes a build-up of gas in bubble trap 152, a user may open
valve 404, thereby causing at least some fluid to be diverted
through integral passageway 308 into integral passage 164, thereby
purging the air from bubble trap 152. If the fluid pressure is too
low to effect purging, valve 404 may be automatically closed to
prevent the introduction of air into the circuit.
[0127] At its downstream end, tubing line 146 is connected from
bubble trap 152 to another integral passageway 150 of cartridge
120. In the embodiment disclosed the bubble trap 152 and
cardioplegia heat exchanger 148 are combined in a single unit which
is separate from cartridge 120 but that fits into the cartridge and
interfaces directly with control unit 10 at cartridge interface
region 20. Bubble trap 152 may be equipped with a bubble sensor
(not shown) that, upon sensing bubbles would cause cardioplegia
purge valve 404 to open and cardioplegia patient valve 96 to close
thus routing the cardioplegia solution to the venous reservoir
through line 164. Air bubbles may be manually purged from bubble
trap 152 by activation of a button (not shown) on user interface
50. Bubble trap 152 may include a filter screen (e.g., a 200 micron
screen) to trap particulates and air and may include a vent (e.g.,
a one-way valve) having a hydrophobic membrane.
[0128] Pressure sensor 18 is provided in cartridge interface region
20 to sense the pressure within passageway 150. During cardioplegia
delivery the monitored pressure may be compared with a
predetermined maximum value to identify if the cardioplegia circuit
has become occluded (e.g., wherein automated stoppage of pumps 36
and/or 35 may be effected and an alarm/indication may be provided
at interface 50). Additionally, the pressure may be monitored
during cardioplegia delivery to insure an adequate cardioplegia
delivery pressure. In the event the monitored pressure falls
outside of user set limits an alarm/indication may be provided at
interface 50 and/or the speed of one or both of pumps 35 and 36 is
either increased or decreased in order to maintain the desired
pressure. For example, the user may set at the user interface a
high pressure limit of 150 mmHg, a low pressure limit of 20 mmHg
and a control point of 100 mmHg. By utilizing the monitored
pressure as a feedback control parameter the system will
automatically adjust the speed of the pumps to maintain pressure at
the control point. If the pressure exceeds for any reason the upper
or lower limit an alarm is activated at the user interface.
[0129] A temperature sensor 153 is provided in cardioplegia valve
block 195 to monitor the temperature of the fluid in line 156. High
and low temperature alarm limits may be set by the user at the user
interface and if those limits are exceeded an alarm is activated at
user interface 50.
[0130] Additionally, if the pressure sensed by cardioplegia line
sensor 18 is below the minimum limit the system automatically
causes either or both the cardioplegia patient valve 96 and
cardioplegia purge valve 404 to close. This prevents retrograde air
from being introduced into the cardioplegia circuit through patient
tube line 156, cardioplegia sample/infusion valve 302 or
cardioplegia purge line 308. Integral passageway 150 is
interconnected to tubing line 156 having a catheter assembly (not
shown) at its distal end for the delivery of the cardioplegia
mixture to a patient.
[0131] Tubing line 156 may be fluidly interconnected via tubing
connector 175 to tubing line 104 and 122 for priming purposes,
wherein tubing line 156 is disconnected from tubing connector 175
after priming. Tubing line 156 may be retainably positioned in
cardioplegia valve block 195 containing a cardioplegia patient
valve 96, a temperature sensor 153, and a bubble sensor 158
provided in the upper component interface plate 12, as described.
If bubbles greater than an acceptable size are detected at sensor
158 the system automatically stops one or both of pumps 35 and 36
and provides an alarm at user interface 50. For purposes hereof,
the above-described components that provide for the flow of blood
from tubing line 128 and crystalloid solution from bags 136,
through tubing line 156, collectively comprise the "cardioplegia
circuit".
[0132] For priming purposes and/or adding blood or other solutions,
disposable assembly 100 further includes one or more spiked tubing
line lengths 160 for interconnection between one or more bags 162
of priming fluid or other solutions and a fluid passageway 164
integrally defined within cartridge 120. An outlet of fluid
passageway 164 is interconnected to a filtered inlet of reservoir
106. Relatedly, it is also noted that the disposable assembly 100
includes a tubing spur 166 interconnected with the venous entry
module 108 of the component interface region for the selective
passage of priming fluid therethrough during priming operations.
Further in this regard, tubing spur 166 includes a pre-bypass
filter 168 for filtering the priming solution to ensure that
particles having a size greater than a predetermined value (e.g.,
greater than 5 microns) are filtered from the system prior to the
initiation of bypass procedures. During priming flow is
automatically directed through pre-bypass filter 168 by closing VLC
46 and opening pre-bypass filter valve 95. Since the pores of the
pre-bypass filter are very fine and would be clogged by blood, as
soon as the presence of blood is sensed at sensor 85 of the venous
entry module valve 95 is closed and the VLC 46 is opened thus
routing the blood directly to the venous reservoir 106.
[0133] For purposes of priming and for filtering in conjunction
with priming, valve assembly 95 is provided to receive tubing line
166 for selective and automatic closure/opening. Similarly, valve
assembly 96 is provided to receive cardioplegia tubing line 156 and
is selectively and automatically operable for opening/closure,
including for example, automatic closure upon detection of gaseous
bubbles in the cardioplegia mixture by bubble sensor 158. One or
more valve assemblies 98 are also provided in component interface
region 12 for automatically and selectively controlling the flow of
priming solution from one or more priming solution bags 162 through
tubing line(s) 160. Similarly, one or more valve assemblies 99 are
provided for selectively and automatically controlling the flow of
crystalloid solution from the one or more crystalloid solution bags
136 through tubing line(s) 133.
[0134] The disposable assembly 100 also includes first and second
tubing suction lines 170 and 172, respectively, each of which are
interconnectable at their distal ends to corresponding suctioning
devices (not shown) for removing fluid from a patient surgical
site. The first and second tubing lines 170, 172 are initially
plugged at the end to allow leak testing, occlusion testing of the
suction pumps 32 and 34 and testing to ensure that the pump loops
are loaded in the pumps in the correct direction. Each of such
tubing lines 170 and 172 are interconnected to corresponding
integral passageways 174 and 176, respectively, within the
cartridge 120, which passageways are in turn interconnected with
tubing loops 178 and 180, respectively.
[0135] Pressure sensors 40 and 42 are provided in cartridge
interface region 20 to monitor the pressures within suction tubing
lines 170 and 172, respectively, which are interconnected with
passageways 174 and 176, respectively. In this regard, the
monitored pressures may be compared with a predetermined negative
pressure value (e.g., corresponding with a risk of blood trauma or
tissue damage or indicating that a suction wand is occluded against
tissue), wherein automated stoppage of pump 32 or 34, respectively,
may be effected upon detection of a pressure that is below the
predetermined negative pressure value and an alarm/indicator may be
otherwise provided at interface 50. A positive pressure may
indicate that a pump is operating in reverse wherein automated
stoppage of pumps 32 and 34 may be effected upon detection of that
positive pressure and an alarm indicator may be otherwise provided
at user interface 50. Further, the user may set at the user
interface a high pressure limit and a low pressure limit and a
desired control point therebetween. The monitored pressure is used
as a feedback control parameter to automatically adjust pump speed
(32 or 34) to maintain pressure at the control point.
[0136] Tubing loops 178 and 180 interface with suction pumps 32 and
34 in the component interface region 12 to provide for the desired
suction. The tubing loops 178 and 180 may be provided with clips
111d and 111e that define the desired unshaped configuration for
the pump interface. Each of such clips 11 id, 111e, may be
color-coded (e.g., yellow for suction) and otherwise configured to
facilitate loading of the tubing loops 178 and 180. The downstream
ends of tubing loops 178 and 180 are interconnected to integral
passageways 182 and 184 of cartridge 120, which passageways 182,
184 are in turn each fluidly interconnected with the integral
passageway 185 for the passage of suctioned blood to sequestration
reservoir 301.
[0137] Disposable assembly 100 may also include a third suction
tubing line 186 having a cannula assembly for interconnection with
the left ventricle or vasculature of a patient's heart so as to
provide for the venting of blood or fluid that may accumulate
therewithin. The third suction tubing line 186 may initially be
plugged at the end to allow leak testing, occlusion testing of the
suction pump 33, and testing to ensure that the pump loop 140 is
loading in pump 33 in the correct direction. Tubing line 186 is
interconnected to an internal passageway 188 of cartridge 120 which
in turn is interconnected to tubing loop 190. Pressure sensor 44 is
provided to monitor the pressure within the suction line 186 which
is interconnected with the passageway 188. Again, the monitored
pressure may be compared to predetermined negative and positive
pressure values, as previously described with respect to suction
lines 170 and 172, wherein automated stoppage of pump 33 may be
effected upon detection of a pressure that is below the
predetermined negative pressure value or above the positive
pressure value and an alarm/indication may be provided at interface
50 upon detection of an out-of-range condition (e.g., either above
the positive pressure value or below the negative pressure
value).
[0138] It should be noted that pressure sensors 40, 42 and 44
function in a manner similar to sensors 14 and 18 except that they
measure both negative and positive pressure values. Tubing loop 190
interfaces with the vent pump 33 provided in component interface
region 12 to provide the desired suction in tubing line 186, as
will be further described. Tubing loop 190 may be provided with a
clip 111f to define a predetermined unshaped configuration for pump
interface. The clip 111f may be color-coded (e.g., green) and
otherwise configured to facilitate loading. The downstream end of
tubing line 190 is interconnected to an internal passageway 192
which, in turn, splits into two passageways 192a and 192b. Flow
through these passageways is controlled with valves 402 and 403,
respectively, to route the fluid either to the sequestration
reservoir 301 or the filtered inlet of the venous reservoir 106, at
the user's option.
[0139] The cartridge 120 in the embodiment illustrated in FIG. 3A
comprises an integral sequestration reservoir 301 for receiving
fluids removed from a patient through first and second tubing
suction lines 170 and 172, respectively, as well as through left
ventricle tubing line 186. In this regard, it can be seen that
integral passageways 182, 184 and 192 are fluidly interconnected to
the sequestration reservoir 301.
[0140] The inclusion of sequestration reservoir 301 in the
embodiment of FIG. 3A allows for selective, discretionary use of
fluids collected therein. For example, such fluids may be processed
to wash and separate red blood cells and other desired components
for later reinfusion. More particularly, it can be seen that
stopcock valve 303 may be provided on cartridge 120, in fluid
connection with sequestration reservoir 301, to provide for the
selective flow of accumulated fluids from sequestration reservoir
301 to a transfer bag (not shown) for subsequent autologous blood
salvage procedures and return of the desired components to the
patient; or for flow directly to an autologous blood salvage
system.
[0141] Alternatively, the embodiment illustrated in FIG. 3A allows
for the return of fluids collected in sequestration reservoir 301
directly to venous reservoir 106 via the inclusion of a valve
assembly 401 in cartridge interface region 20 that interfaces with
an added integral passageway 305 in cartridge 120. Valve 401 may be
selectively opened/closed by a user or maybe automatically opened
when the sequestration reservoir is full. When valve 401 is open,
fluids collected in sequestration reservoir 301 will flow through
the integral passageway 305 within cartridge 120, and then through
tubing line 129 to a filtered inlet port at venous reservoir
106.
[0142] A vent 307 is provided at the top of sequestration reservoir
301 to vent gas that may accumulate in the reservoir 301.
Additionally, the cartridge interface region 20 may be provided
with one or more level sensors for monitoring the fluid level
within sequestration reservoir 301. In this regard, a first level
sensor 320 may be disposed adjacent to the top end of sequestration
reservoir 301, wherein upon sensing of fluid at a predetermined
level within reservoir 301, control unit 10 will operate so as to
automatically open valve 401 so as to flow fluid from sequestration
reservoir 301 to venous reservoir 106. The system may be set up by
the user so that, upon sensing fluid at the upper level sensor, the
control unit 10 may stop the suction and vent pumps and provide an
alarm so that the user can empty the sequestration reservoir.
Alternatively, instead of stopping the vent pump 33, the control
unit 10 may automatically close valve 402 and open valve 403 to
re-route the vent pump outlet from the sequestration reservoir to
the venous reservoir. A second level sensor 322 may also be
provided and disposed downward from the first sensor, wherein upon
the detection of fluid, an alarm/indication may be provided at user
interface 50. Alternatively, sequestration reservoir 301 may be
provided with a continuous level sensor such as that described in
connection with FIG. 12. Alternatively, the level in the
sequestration reservoir 301 could be sensed continuously by
measuring the pressure at the bottom of the reservoir through the
membrane with a pressure sensor.
[0143] Sequestration reservoir 301 includes a defoamer element 795
which may be vertically disposed to facilitate in the removal of
gas from fluid accumulating in venous reservoir 301. After
cartridge 120 is loaded into its mounting assembly 21, defoamer
push bar 790 is advanced to a position where it applies pressure
through the vinyl backing of cartridge 120 against the side of
defoamer 795. This pressure ensures that there are no flow paths
between defoamer 795 and the vinyl backing and that any fluid which
enters sequestration reservoir 301 is caused to flow through the
defoamer.
[0144] It should also be noted that, since in many potential
applications, the blood collected through left ventricle tubing
line 186 may be of a high quality nature, the embodiment
illustrated in FIG. 3A comprises further features that allow for
the selective, direct flow of such blood from the cartridge 120 to
venous reservoir 106. In particular, FIG. 3A illustrates the
inclusion of integral passageway spurs 192a and 192b, each of which
interface with a corresponding valve assembly 402 and 403,
respectively, provided in the cartridge interface region 20. In the
event that a user would like blood collected from the left
ventricle to be collected in sequestration reservoir 301, the user
may selectively control valve 403 to be closed and valve 402 to be
open whereupon the collected blood will flow through integral
passageway spur 192a into integral passageway 185 to sequestration
reservoir 301. Alternatively, a user may selectively cause valve
402 to close and valve 403 to open whereupon the collected blood
will flow through integral passageway spur 192b, adjoining integral
passageway 164, and out of cartridge 120 through tubing line 129 to
a filtered inlet port of venous reservoir 106.
[0145] The component interface region may comprise a level sensing
assembly 87 positioned in immediate, predetermined relation to the
region in which venous reservoir 106 is mounted. In this regard,
the level sensing assembly 87 is operable to monitor the level of
fluid within the venous reservoir 106 on an ongoing basis during
procedures. Such monitored fluid level may be presented both
graphically and in volumetric measure terms at user interface 50.
Additionally, the fluid level value may be monitored in relation to
predetermined minimum and maximum values, wherein automated stowage
or stoppage of pump 31 may be effected when the fluid level drops
below corresponding predetermined minimum values and wherein an
alarm/indicator may be otherwise provided at user interface 50 upon
detection of an out-of-range condition.
[0146] One embodiment of such a level sensor is illustrated in
function form in FIG. 12. In this embodiment, level sensor 87
operates on the theory of time domain reflectometry which uses
pulses of electromagnetic energy to measure distances or fluid
levels. The level sensor 87 generates an initial pulse 97a. When
the initial pulse reaches the surface of the blood in reservoir
106, part of the pulse is reflected. The level in the reservoir is
determined by the measured differential of the reflected pulse 97c
and the transmitted pulse 97b in a manner known to those of skill
in the art. Level sensor 87 is mounted internally to the control
unit 10 in a location adjacent to the venous reservoir 106. The
level sensor 87 is oriented such that the level sensor is
approximately parallel to the vertical wall of the venous reservoir
and extends from the lower most portion to the upper most portion
of the venous reservoir. In between the level sensor 87 and the
venous reservoir 106 is a thin wall, covering or coating that is
thin enough and made of a material (e.g. plastic) permitting the
transmission of signals into the venous reservoir from the sensor
as well as receiving reflected signals from the venous reservoir,
in particular reflections from the fluid level in the venous
reservoir. The thin wall, covering, or coating would allow
positioning the level sensor as close as possible to the external
wall of the venous reservoir to aid in signal transmission and
reception. The wall could be a part of control unit 10. The level
sensor is positioned approximately in a vertical plane such that
the transmitting and receiving portions of the sensor would cover
the entire height of the venous reservoir to ensure the venous
reservoir level could be sensed from a full to empty condition.
While a vertical orientation is described, an angled orientation
would also functionally work and may add resolution to the level
signal.
[0147] As previously noted, user interface 50 includes a main
display 54, user control knob 52 and backup display 55. The main
display 54 and backup display 55 may be provided to display
monitored parameters regarding one or more of the fluid circuits
discussed hereinabove, to provide alarm indications as noted
hereinabove, and to establish predetermined minimum/maximum or
control values for monitoring and control purposes. Of particular
note, the backup display 55 is located immediately adjacent to
control knob 52, wherein when a given parameter is being
established via control knob 52, a user may readily observe the
backup display 55 as the knob 52 is being manipulated.
[0148] Another embodiment of the disposable assembly 100 and
component interface of control unit 10 are schematically
illustrated in FIG. 3B. As can be seen, the embodiment illustrated
in FIG. 3B is similar in many respects to the embodiment
illustrated in FIG. 3A. As such, components having common
functionality between the two embodiments are labeled with the same
reference number and the corresponding description of such
components set forth above is applicable. Features unique to the
embodiment illustrated in FIG. 3B are described below.
[0149] As shown in FIG. 3B, tubing line 116 includes a first spur
116a interconnected to an upstream side of an arterial filter 118,
and a second tubing spur 116b interconnected to a downstream side
of arterial filter 118. Second tubing spur 116b may be utilized for
replacement/bypass of arterial filter 118, while the first tubing
spur 116a is utilized during oxygenated blood return to a patient
during cardiopulmonary bypass procedures. In particular, valve
assembly 90 is provided to receive tubing spur 116a, and valve
assembly 91 is provided to receive tubing spur 116b, wherein valve
assemblies 90, 91 may be selectively and/or automatically
opened/closed together with other valve assemblies, to establish
the desired fluid flow (e.g., through tubing spurs 116b during
filter replacement, and through tubing spur 116a during bypass
procedures).
[0150] Valve assembly 93 is provided to receive tubing line 125 and
may be selectively and automatically opened/closed, including, for
example, selectively opened for retrograde cerebral perfusion or to
quickly reprime the venous tubing line 104 after initial bypass
procedure ends in the event the patient needs to go back on
bypass.
[0151] During bypass procedure control unit 10 may operate to close
tubing line 122 and direct blood flow from arterial filter 118
through purge line 119 when bubbles are detected by sensor 114.
Further, in the embodiment of FIG. 3B, control unit 10 may operate
to close tubing line 122 by closing arterial line valve 92 when
gaseous bubbles are detected by sensor 114 and/or sensor 126
thereby causing blood to flow back to the reservoir 106 via tubing
line 125. For such purposes, tubing line 125 is interconnected to
the venous entry module 108 of the venous circuit as described
hereinabove. During cardioplegia delivery (e.g., when pump 35 is
operating and valve 96 is open) and/or during hemoconcentration
procedures (e.g., when pumps 37 and 38 are operating to circulate
blood through a tubing hemoconcentration assembly 134), the
monitored pressure may be compared with a corresponding
predetermined minimum value to insure an adequate fluid pressure at
cartridge 120 (e.g., so as to reduce any risk of cavitation or air
transfer across the membrane of oxygenator 112). In the event the
monitored pressure is below the desired level, automated stoppage
of pump 35 (e.g., in the case of cardioplegia delivery) and
automated stoppage of pumps 37 and 38 and closure of valve 96
(e.g., in the case of hemoconcentration procedures) may be effected
and an alarm/indication may be provided at interface 50.
[0152] Integral passageway 130 is fluidly interconnected to a
tubing loop 132, and may also be fluidly interconnected to a
tubing/hemoconcentrator assembly 134. In the later regard,
tubing/hemoconcentrator assembly 134 may be optionally
interconnected to the disposable assembly 100 when use of a
hemoconcentrator 134a and waste bag 134b is desired.
[0153] Pressure sensor 86 may also be provided to sense the
pressure within the tubing/hemoconcentrator assembly 134 in the
event that a hemoconcentrator is employed. In this regard, the
monitored pressure may be compared with a predetermined minimum
pressure value necessary to insure flow through the membrane of
hemoconcentrator 134a, wherein if the pressure falls below the
minimum an alarm or other indication may be provided at user
interface 50. Further, the monitored pressure in assembly 134 may
be compared with a predetermined maximum pressure value. A
monitored pressure that exceeds the maximum value may indicate that
the outlet of hemoconcentrator 134a has become occluded, wherein
automated stoppage of pump 37 and pump 38 may be effected and an
alarm or other indication may be provided at user interface 50.
[0154] In the embodiment of FIG. 3B the downstream end of tubing
loop 140 is interconnected with integral passageway 142 having a
filter 144 interposed therewithin. Filter 144 serves to filter
particulates greater than a predetermined size (e.g., greater than
0.2 microns via a filter screen). Filter 144 may also comprise at
least one vent (not shown) having a hydrophobic membrane for
venting air bubbles. In this regard, filter 144 may include two
hydrophobic vents (not shown), one on each side of a vertical
filter screen, for venting air bubbles from a priming solution
during priming and for venting air bubbles from solutions passing
therethrough (e.g., cardioplegic crystalloid solution during
cardioplegia delivery).
[0155] Pressure sensor 16 is provided in cartridge interface region
20 for sensing the fluid pressure within integral passageway 142.
The monitored pressure may be compared with a predetermined value
during cardioplegia delivery (e.g., when pump 36 is operating and
valve 96 and one of the valves 99 are open). If the monitored
pressure exceeds the predetermined value (e.g., indicating the
filter 144 is clogged), then an alarm/indication can be provided at
interface 50, and the filter 144 may be automatically or manually
bypassed (e.g., via operation of valve 93 so as to open bypass line
143).
[0156] For purposes of priming and for filtering in conjunction
with priming, valve assemblies 94 and 95, respectively, are
provided to receive tubing lines 119 and 166, respectively, for
selective and automatic closure/opening.
[0157] With further regard to the delivery of the crystalloid
solution, valve assembly 93 is provided to receive crystalloid
bypass tubing line 143 for selective and automatic opening/closure
thereof, including for example opening upon clogging of crystalloid
filter 144, as detected by pressure sensor 16. That is, in the
event sensor 16 detects a pressure greater than a predetermined
value, valve assembly 93 can be automatically and/or selectively
opened wherein crystalloid solution will flow through bypass tubing
line 143 and back into integral passageway 146.
[0158] The downstream ends of tubing loops 178 and 180 are
interconnected to integral passageways 182 and 184 of cartridge
120, which passageways 182, 184 are in turn each fluidly
interconnected with the integral passageway 164 for the passage of
suctioned blood out of cartridge 120 and through tubing line 129 to
the filtered inlet of venous reservoir 106 for reuse.
[0159] Further, passageway 164 may be interconnected to an outlet
(not shown) that may be selectively utilized for passing suctioned
blood into a separate reservoir (not shown).
[0160] Finally, disposable assembly 100 may also include a transfer
bag/tubing assembly 194 (not shown in FIGS. 2A and 2B) that may be
utilized for receiving blood from passageway 130 of cartridge 120.
The transfer bag/tubing assembly 194 may be employed, for example,
to remove excess fluid from the circuit during bypass procedures,
to retrieve blood from the circuit post bypass for later reinfusion
to the patient or for cell-saving procedures.
[0161] Pressure sensor 14 may also be used as a means of checking
for proper arterial cannula placement before going on bypass. When
arterial patient valve 92 is open during test connection mode as
described hereafter, the patient pressure at the cannula can be
read at sensor 14.
[0162] While FIGS. 3A and 3B correspond with embodiments
implementing various aspects of the present invention, other
potential embodiments which incorporate one or more of the
inventive features of the present invention would be apparent to
those skilled in the art.
[0163] V. Disposable Cartridge
[0164] As illustrated in FIGS. 13-24, the perfusion cartridge 120
can be made of a variety of materials including polymeric
materials, metals and composite materials. In a preferred
embodiment, the perfusion cartridge 120 of the present invention is
formed from polymeric materials which are thermoformed medical
grade plastics. Cartridge 120 has a plurality of fluid passageways
integrally defined therewithin. By way of example, cartridge 120
may be constructed from a clear, molded front piece (e.g., molded
plastic which defines all but a back side of each integral
passageway), and an interconnected, pliable back layer (e.g., a
vinyl sheet that defines a back side of each integral passageway)
attached thereto. In addition to the integral passageways,
cartridge 120 may include one or more passive components. Such
components may include one or more filters and bubble traps.
Various conduits may be formed into the perfusion cartridge 120
during manufacturing such that each of the top and bottom plates or
pieces partially define portions of the conduits. Typically, the
front portion 802 is translucent to allow for visual inspection of
each of the conduits that flow through the cartridge 120. In
addition, the integrated fluid conduits are located at various
depths and can pass above or below each other.
[0165] FIGS. 13-24 are various views of cartridge 120. FIG. 13 is a
front perspective view. FIG. 14 is a front plan view. FIGS. 15 and
16 are right and left side views, respectively. FIGS. 17 and 18 are
top and bottom views, respectively. FIG. 19A is a back plan view
and FIG. 19B is a back perspective view. FIG. 20A is a
cross-sectional view along line A-A of FIG. 19A. FIG. 20B is a
detail view of a portion of FIG. 20A. FIG. 21 is a cross-sectional
view taken along lines B-B of FIG. 19A. FIG. 22 is a back plan view
with the flexible back layer removed to better show the various
fluid channels and related components within cartridge 120. FIGS.
23A, 23B, 24A, and 24B are partial views of a valve station located
in cartridge 120.
[0166] In each of these figures, components that have been
previously described retain the same reference numerals. This
includes the various internal passageways or fluid conduits formed
by the cartridge. The various inlet and outlet ports of the
cartridge have been labeled with the reference numeral of the
external tubing line connected at the port. Those portions of the
cartridge which interface with pressure or temperature sensors or
with valves comprise sensor or valve stations and are labeled
individually with the reference numeral of the sensor or valve with
which they interface followed by a small "a". Thus, for example,
the sensor station interfacing with cardioplegia line pressure
sensor 18 is referenced as 18a. Features of cartridge 120 not
previously described are discussed below.
[0167] Cartridge 120 includes a front substantially rigid portion
802. Front portion 802 defines substantially all of the structure
of the various components and passageways of the cartridge. For
example, front portion 802 defines the shape and contour of
sequestration reservoir 301 except for the back portion thereof. A
flexible back layer 804 is connected to the back side of front
portion 802. Any flexible, durable, fluid impermeable material
which is suitable for contact with a patient's blood may be used. A
suitable material is a sheet of vinyl. The sheet can be attached to
the front portion by use of medical adhesives or welding techniques
known to those of skill in the art. The back layer may be comprised
of a flat sheet or, alternatively, can be formed into a contoured
shape. Formed elements in the vinyl can assume various formed
shapes and can include pressure diaphragms as shown in FIGS. 19A
and 19B, valve diaphragms as shown in FIGS. 23A, 24A, 23B, and 24B,
fluid passageways matching those on the cartridge as shown in FIGS.
19B and 20B, sequestration reservoir 301 and sequestration
reservoir defoamer 790 as shown in FIGS. 15 to 21. The pressure
diaphragms isolate the pressure sensor from the cartridge to
provide more accurate pressure readings. The valve diaphragms help
lower the resistance to valve opening and closing, and can provide
a transition zone in the fluid flowing from the passageway through
the valve. Fluid passageways can be shaped to smooth fluid flow
and/or provide a more consistent cross sectional fluid volume
through passageways particularly where entering or exiting other
features such as ports, pressure sensing regions or valve regions.
The sequestration reservoir volume may be increased and/or flow
enhanced through vinyl forming. In particular, by forming a pocket
in the vinyl, the defoamer may be placed into the pocket as best
seen in FIG. 20A. A pocket also helps form a sealing interface when
positioned against defoamer push bar 790 located in the cartridge
interface region 20. Vinyl forming may be accomplished by forming
techniques known to those skilled in the art.
[0168] As seen in FIGS. 20A and 21, the sequestration reservoir
includes a defoamer support element 806. Support element 806
comprises a plurality of struts 806a and 806b which are spaced
apart on either side of defoamer 790 and which support defoamer 790
in the sequestration reservoir 301.
[0169] As shown in FIGS. 23A, 23B, 24A, and 24B, the valve stations
include a valve chamber 808 in the cartridge 120. The valve chamber
808 includes at least first 810 and second 812 passageways. A
flexible member 804 is positioned over the valve chamber 808 above
first 810 and second 812 passageways.
[0170] Typically, first passageway 810 contains a raised lip
portion 816 which extends toward flexible back layer 804. A portion
of backlayer 804 adjacent raised lip portion 816 is formed as a
flexible pleated member 814. A plunger 818 provided in the
structural interface is located over the valve chamber 808. To
close the valve, plunger 818 is caused to impact and deflect the
flexible member 814 to contact the raised lip portion 816 of the
first passageway 810. This deflection and contact prevents fluid
from flowing out of or into the first conduit 810. To open the
valve, the plunger 818 is retracted from the raised lip portion 816
such that fluid pressure displaces the flexible member 814 from the
raised lip portion 816 of the fluid conduit 810.
[0171] In a further embodiment of the present invention, the
cartridge 120 includes a first integral passageway path which
occurs in a first plane. The first integral passageway has an entry
port and an exit port from the cartridge 120. The first integral
passageway, thus, defines first and second areas in cartridge 120,
both lying in the first plane and being separated by the first
integral passageway. Cartridge 120 also includes a second integral
passageway which has an entry port and an exit port from the
cartridge. The entry port of the second integral passageway occurs
in the first area of the first plane, and the exit port of the
second integral passageway occurs in the second area of the first
plane. Thus, the first and second conduit paths crossover at a
point. At the point of cross-over of the first and second integral
passageways, the second integral passageway occurs in a second
plane.
[0172] In the present invention, as shown in FIGS. 13-24, the
perfusion cartridge 120 can be interconnected with a number of
fluid circuits. The fluid circuits include a cardiopulmonary
circuit which include the venous and arterial circuits, a
cardioplegia circuit, a cardiotomy or suction/vent circuit and a
fluid management or priming circuit all as previously discussed.
The cardiopulmonary circuit is designed to functionally replace
and/or supplement the heart and lungs during heart surgery. The
cardioplegia circuit delivers cardioplegia to the heart to
discontinue beating in a manner that will facilitate operative
procedures and minimize damage to the myocardium. The cardiotomy
circuit is used to withdraw or suction blood and other fluids from
the open heart or chest cavity and deliver it to the
cardiopulmonary circuit. The fluid management circuit is used to
provide priming fluid, i.e., blood, to the disposable assembly 100
and maintain a proper flow of fluid in the other circuits. In
another embodiment, two cartridge assemblies may be interconnected.
For example, a first cartridge assembly including the cardioplegia
circuit may be connected to a second cartridge assembly including a
cardiopulmonary circuit, a cardiotomy circuit and a fluid
management circuit can be interconnected.
[0173] In the embodiment described herein the cardiopulmonary
(arterial and venous) circuit is not interconnected with the
disposable cartridge 120 except for air purge and fluid sampling
functions. However, it should be appreciated that the
cardiopulmonary (arterial and venous) circuit could be included
within the cartridge 120.
[0174] VI. System Architecture.
[0175] Control unit 10 includes a plurality of processors which
together with system user interface 50, pump user interfaces
31b-36b and pump control knobs 31a-36a operate to control various
components of the control unit 10 according to preprogrammed and/or
user established instruction sets and user input. In this regard,
and referring now to the block diagram of FIG. 25, a control unit
10 comprising processors 300, 306, 304 and 312 is illustrated.
Processor 300 is provided to interface with the main display 54 of
the user interface 50, and may be a personal computer provided with
graphics to facilitate operation of the main display 54.
Monitor/control processors 306 are separately provided for
automated monitoring and control, respectively, of the various
components comprising control unit 10. Backup display 55 may also
be provided with redundant monitoring/control processors 304,
separate from processors 300 and 306. It is also noted that valves,
sensors, flow control components, temperature control components,
gas circuit components or other components comprising component
interface region 12 may also be separately provided with separate
monitoring and control processing chips. Each pump 31-36 also has
its own monitor/control processor pairs 312. All of the
above-mentioned processors are interconnected through a
communications network.
[0176] Processors 300, 306, 304, and 312 are interconnected to
receive monitoring signals from the various pressure, bubble,
temperature, oxygen saturation, hematocrit, level, flow, and other
sensors 314 that comprise the control unit 10, and that interface
with the disposable assembly 100. In this regard, the monitored
signals provide an indication of measured values which may be
processed at one or more of the processors in relation to one or
more predetermined maximum/minimum values so that one or more of
the processors may issue control signals to flow control components
380, temperature control systems 330 or gas circuit components 340
based on preprogrammed instruction sets and/or other indication
signals to system user interface 50 and/or pump user interface
31b-36b to prompt a user regarding a monitored condition of
potential concern. As will be described, system user interface 50
allows a user to input or modify one or more of the processors
parameter settings which one or more of the processors rely upon in
issuing instruction signals to flow control components 380,
temperature control systems 330 and/or gas circuit components 340
and indication/alarm signals to system user interface 50.
[0177] As indicated in FIG. 25, the flow components 380 comprising
the control unit 10 include the various pumps and valve assemblies
described hereinabove, as well as the venous line clamp 46. Based
on signals received from the various pumps or pressure sensors, the
processors may be preprogrammed to automatically calculate flow
rates in the various fluid circuit lines for monitoring and display
at user interface 50. The temperature control systems 330 include
controls for establishing the temperature and flow of
heating/cooling fluid through the cardioplegia heat exchanger 148
and for controlling the temperature and flow of the heating/cooling
fluid circulated through a heat exchanger interconnected to or
integrally provided with oxygenator 112. Other features and
functions of the system architecture are described in other
sections herein.
[0178] 1. Gas Circuit
[0179] Referring now to FIG. 26, a schematic block diagram for the
gas circuit 340 referenced in FIG. 25 will be briefly described.
The gas circuit 340 may comprise a plurality of external gas
sources for air (342a), for O.sub.2 (342b) and for an
O.sub.2/CO.sub.2 mixture (342c), having corresponding in-line
filters 344a, 344b and 344c, and pressure regulators 346a, 346b,
and 346c, for flowing the respective gases via corresponding check
valves 348a, 348b, and 348c into a valve manifold 350. Valve
manifold 350 includes valves 352a, 352b and 352c set to establish
the desired flow/relative percentage of each gas type. Flow meters
354b and 354c may be provided upstream (as shown) or downstream of
valve manifold 350 for the O.sub.2/CO.sub.2 source line and O.sub.2
source line and/or air source line. As illustrated, the three gas
source lines may flow into a common line downstream of the manifold
350. The common line then passes through a total flow meter 356.
From flow meter 356 the single stream may be passed through a
vaporizer 358 outside of control unit 10 for introduction of an
anesthetic agent. A pressure sensor 360 may be provided to monitor
the fluid pressure at filter 362. In the event the pressure exceeds
a predetermined maximum value (e.g., indicating that filter 362 is
clogged), an alarm or other indicator may be provided at user
interface 50. Additionally, to insure the desired pressure at
oxygenator 112, an additional pressure sensor 364 may be utilized
downstream of the filter 362 and upstream of the oxygenator 112. In
the event the pressure exceeds a predetermined maximum value,
valves 352a, 352b, and 352c may be closed partially or fully to
prevent gas bubbles from crossing the oxygenator membrane into the
blood. The gas from filter 362 then flows into the oxygenator 112
via inlet port 518a provided in the control unit 10 through the
oxygenator 112, and into the control unit 10 via the outlet port
518b (on FIG. 8B). At that point, the gas flow stream will comprise
the oxygen-depleted, CO.sub.2-containing exhaust from oxygenator
112. Such exhaust may then be passed through a liquid leak detector
366 for monitoring purposes (e.g., to detect any leakage through
the oxygenator membrane of blood or priming fluid), and into a
scavenge line. An optional gas concentration monitoring system may
be included having sampling pumps 368a and 368b to draw gas samples
downstream and upstream, respectively, of oxygenator 112. The gas
samples may be passed through a dryer 369, analyzed by monitor 370,
and returned to the scavenge line. The flow meters 354b, 354c, 356,
and monitor 370 may be interconnected to user interface 50 to
provide information for display and monitoring for alarm
indications. The information provided by the flow meters and
concentration sensors, combined with the known blood flow rate,
venous saturation, hematocrit and temperature, can be used to
estimate arterial blood gas concentrations (e.g., pO.sub.2 and
PCO.sub.2). The gas concentrations measured by the monitor 370 can
be compared to the concentrations calculated from the flow rates
measured by flow meters 354b, 354c, and 356. If the difference
between measured and calculated concentration exceeds a
predetermined maximum value, an alarm/indicator may be provided at
user interface 50. The arrangement of flow meters and valves allows
a comparison of flow meter measurements to verify correct operation
of individual flow meters. For example, valves 352c and 352a could
be closed, allowing flow only from the O.sub.2 source through flow
meters 354b and 356. The measured flow rates from meters 354b and
356 should be equal if the flow meters are operating properly.
Similar checks/tests could be performed with respect to verifying
gas source composition and connection.
[0180] VII. System User Interface.
[0181] The system user interface 50 includes a control knob 52 and
user displays 54 and 55 that provide for the automatic redundant
display of alarm indications and certain monitored parameters, and
provide for selective user control of various system components.
Both main display 54 and backup display 55 may provide a functional
user interface (e.g., via touch screen capabilities). Important
subsets of the various features described below with respect to
main display 54 may also be provided at backup display 55, either
all the time or if failure of main display 54 is detected by the
system or by the user. In addition to its backup display functions,
display 55 serves primarily as a numeric data entry screen, as
described below.
[0182] Numeric data entry is accomplished by using the control knob
52 and both user displays 54 and 55, as follows. The user contacts
a touch screen button on either display 54 or 55 to initiate
modification of a particular numeric value represented by that
button. The value being modified then appears (usually in a large
font) on display 55, as well as appearing within the button
originally contacted on display 54 (or its analog on 54, if the
original button was on display 55). At this point, the knob 52 may
be turned to affect changes in the value displayed in both places.
This dual display concept is to provide redundant display of
important data parameters as are they are being adjusted, thereby
giving an important safety cross-check against incorrect data
entry. In most cases, as the number is being adjusted on the
screens, it is also taking immediate effect in the system (on-line
adjustment). For example, turning the knob to adjust venous line
clamp position causes the clamp to move immediately to the value
entered. Data entry is terminated by pressing the knob 52 in, or by
touching the original touch button or anywhere else on the touch
screen. Because of the on-line nature of such adjustments,
terminating the data entry is not in anyway "confirming" or
"setting" the value entered; that has already happened. Terminating
the data entry simply exits the adjustment mode for that particular
value. There are many examples of specific data entry actions
throughout this section.
[0183] FIGS. 27-33 illustrate examples of one embodiment of the
system user interface 50, and are presented for illustrative
purposes. The arrangement, controls, and information presented on
the user interface are not limited to that shown here.
[0184] As shown in FIG. 27, processor-driven display 54 is
controlled to define three display regions for information
presentation and user control. The screen of display 54 comprises a
first region 200, a second region 220, and a third region 240. The
first region 200 provides for automatic alarm status messages and
corresponding user control buttons that are presented when
monitored system parameters exceed/fall below predetermined
established values (e.g., factory set values or user established
values). The second region 220 and third region 240 will be
described further hereinbelow.
[0185] Alarms:
[0186] The first region 200 of display 54 provides alarm and status
messages that are presented when certain monitored system
parameters exceed/fall below selectable, predetermined established
values and/or an otherwise undesired condition is detected. FIGS.
28A-28F illustrate a variety of such messages. In this regard, it
should be noted that the messages are presented in relation to
their relative degree of importance. That is, in the illustrated
embodiment, messages which are of predetermined "critical" nature
are displayed against a red box background while messages of a
predetermined "warning" nature are displayed against a yellow box
background. Further, it should be generally noted that when a
condition is detected that would trigger a "critical" message such
message will be presented together with a touch screen button that
may be immediately contacted by a user to override the alarm. That
is, detection of a "critical" condition may result in automatic
stoppage of a given system component (e.g., pump 31 or pumps 35 and
36), in which case, the "critical" message may be presented with a
touch screen button that may be contacted to restart the stopped
component. Alternatively, detection of a "critical" condition may
result in display of a button (e.g., with the "critical message")
that may be contacted by a user to effect an immediate stoppage of
a predetermined component displayed with the message (turn off the
override). Additionally, it should be noted that with respect to
the "critical" messages, a predetermined hierarchy is preferably
established wherein the order of presentation of such "critical"
messages will be determined in relation to the hierarchy as
preprogrammed at the embedded processor.
[0187] The following are examples of "critical" conditions that may
trigger an automatic response and a "critical" alarm message. Many
other critical alarms may exist in the system:
[0188] 1. Detection of an air bubble in tubing line 122 or tubing
line 156. Such a detected condition may automatically trigger
stoppage of pump 31 and/or pumps 35 and 36. Selective, user
response buttons may be provided with the corresponding "critical"
messages to provide a user with the touch screen capability to
restart the stopped pump.
[0189] 2. Detection of a pressure in line 122 or of a pressure in
line 156 that exceeds a corresponding predetermined maximum value.
Detection of this condition may trigger an automatic stoppage of
pump 31 and/or pumps 35 and 36. Alternatively, the pump may slow
until the desired range is re-achieved. Again, button displays may
be provided for selective, user restart of the affected pumps.
[0190] 3. Detection of a volume level in venous reservoir 106 that
exceeds or falls below a predetermined level.
[0191] Various detected conditions are reflected by FIGS.
28A-28F.
[0192] Referring specifically to FIG. 28A, a "critical" alarm box
202a' is presented with the message:
[0193] "LOW LEVEL-Pump Stopped"
[0194] This message indicates that the volume in reservoir 106 has
been detected to have fallen below a predetermined alarm value. The
message also indicates that pump 31 has been automatically stopped.
It should also be noted that the message box 202a' provides a touch
screen button entitled "Restart Pump" 202a". Button 202a" allows a
user to immediately take responsive action, i.e., to contact the
"Restart Pump" button 202a" so as to start arterial pump 31, by
overriding the alarm.
[0195] At this point, it should also be noted that in the event of
a "critical" message (e.g., the message is displayed against a red
background), the control unit 10 may provide for a first audible
alarm to a user. Further, in the event of a non-critical message
(e.g., a "warning" message displayed against a yellow background),
control unit 10 may provide a second audible alarm that is
different than the first. Correspondingly, the first region 200 of
display 54 may be provided with a touch screen "Mute" button 204
which allows a user to selectively disable the most recent audible
alarm. That is, audible alarms may be successively and separately
"muted" in relation to each successive triggering-alarm event. The
"Mute" button 204 only appears when there is one or more audible
alarms currently sounding, and it disappears after being pressed
(thereby stopping the audible signal) until the next triggering
event occurs causing a new alarm and audible to occur. Thus, the
"Mute" button only appears when needed.
[0196] FIG. 28B illustrates an alarm box 202b' with the
message:
[0197] "LOW LEVEL-Pump On".
[0198] This message indicates that the volume in reservoir 106 has
been detected to have fallen below a predetermined value and that
pump 31 is on (because the alarm is overridden). Block 202b' also
provides a touch screen button entitled "Stop Pump" 202b" to allow
a user to immediately stop arterial pump 31 upon contact with
button 202b".
[0199] In FIG. 28C an alarm box 202c' is presented with the
message:
[0200] "LEVEL OK-Pump Stop Disabled".
[0201] This message indicates that the volume in reservoir 106 is
within an acceptable range but that the automatic pump stoppage
feature of control unit 10 has been overridden (e.g., the user has
contacted the button 202a" shown in FIG. 28A). To reactivate the
automated pump control feature (turn off the override), a user may
contact button 202c".
[0202] FIG. 28D illustrates a plurality of "critical" alarm boxes
corresponding to response buttons 203a", 203b", and 203c" each of
which would be illustrated against a red background, and a single
"warning" alarm box 206a' which would be presented against a yellow
background. FIG. 28E illustrates a plurality of "critical" alarm
boxes and a plurality "warning" alarm boxes. The presence of the
"MORE button 208a indicates that there are more alarms than can be
displayed within region 200, which can be selectively cascaded into
the second display region 220 via contact with the "MORE" button
208a, as shown in FIG. 28F. Pressing the "LESS" button 208b in FIG.
28F will collapse the alarms back within region 200, as shown in
FIG. 28E.
[0203] Dedicated Area:
[0204] The second region 220 presents selected, predetermined
important information sets to monitor bypass parameters, including
values corresponding with selected fluid flow parameters monitored
by various components of control unit 10, as well as other
parameters monitored by external systems. More particularly, in the
screen display embodiment illustrated in FIG. 29, five different
information sets are presented in five corresponding sub-regions
222, 224, 226, 228 and 230, having the sub-region headings of
"Venous", "Arterial", "Cardioplegia", "Blender" and "Other",
respectively. The alphanumeric information in the different
sub-regions may be color coded for ready observation (e.g., the
alphanumeric information may be blue in "Venous" sub-region 222,
red in "Arterial" sub-region 224, yellow in "Cardioplegia"
sub-region 226 and white in "Blender" and "Other" sub-regions 228
and 230, respectively).
[0205] The information displayed in sub-region 222 under the
"Venous" heading pertains to parameters of the venous blood flowing
from a patient into venous reservoir 106 of disposable assembly 100
during a bypass procedure. More particularly, the monitored venous
blood values include a measure of the venous blood oxygen
saturation (i.e., "SAT"), venous blood hematocrit (i.e., "HCT") and
venous blood temperature (i.e., "Temp"). Such values are monitored
by corresponding oxygen saturation hematocrit and temperature
sensors 85 and 81, respectively, in the component interface region
12. Of note, information regarding the volumetric content of venous
reservoir 106 is provided both in an animated manner and
numerically by the graphic reservoir in sub-region 222. That is, as
the level of fluid raises and lowers in venous reservoir 106 during
a bypass procedure, a corresponding animated fluid level (e.g.,
illustrated in red) will be presented in the graphic venous
reservoir shown in sub-region 222. Additionally, a numeric
representation of the volumetric level within venous reservoir 106
will be increased/decreased. The volumetric level of fluid within
reservoir 106 is determined via the level sensor 87 located in
component interface region 12.
[0206] The "Venous" sub-region 222 further includes object buttons
222a, 222b and 222c having touch screen capabilities to allow a
user to selectively control venous line clamp 46 of the component
interface region 12 on control unit 10. In particular, the "Full
Open" and "Full Close" buttons 222a and 222c, respectively, allow a
user to selectively, fully open and fully close venous line clamp
46 upon screen contact. Object button 222b allows a user to select
a desired percent of fluid passage through venous tubing line 104
at venous line clamp 46. That is, pursuant to contact with button
222b, a user may then utilize the control knob 52 on system user
interface 50 to set a desired percentage for fluid passage through
tubing line 104 at venous line clamp 46. The desired percentage is
established by dialing/rotating knob 52 until the desired value is
displayed by main display 54 and back up display 55. The VLC is
moved immediately to the desired position as the knob is moved. A
user may then either push the knob 52 or contact button 222b or any
other touch screen portion of display 54 to exit the adjustment
mode. For example, if venous line clamp 46 is in an open position
and a user desires to reduce the flow of venous blood flow into
venous reservoir 106 (e.g., due to a detected high level of fluid
within venous reservoir 106), a user could contact button 222b and
"close" venous line clamp 46a desired amount via rotation of
control knob 52. The set flow percentage will be presented in an
illuminated manner within the center of object button 222b and on
the back up display 55. The percentage is displayed as a percent of
flow expected if the venous line clamp was fully (100%) open.
[0207] The information presented within sub-region 224 under the
heading "Arterial" pertains to ongoing monitored parameters of the
blood passing from venous reservoir 106 through oxygenator 112 for
return to a patient. More particularly, the monitored parameters
include the pressure of the oxygenated blood in line 122 (i.e.,
"Pressure"), the flow rate of the blood at pump 31 (i.e., "Flow")
and the temperature of the blood in line 122 (i.e., "Temp."). The
pressure and temperature values are monitored on an ongoing basis
by the pressure sensor 14 and temperature sensor 88 provided in
component interface region 12 of control unit 10. The flow rate may
be automatically determined by monitoring the RPMs of arterial pump
31 at the pump processor 312 and by using the monitored RPM values
with stored stroke volume-values corresponding with pump 31 to
calculate flow rate, or to display the flow rate from a flow meter.
Such flow rate may be automatically adjusted to compensate for any
blood flow downstream of pump 31 that is not directed through
arterial tubing line 122. Arterial blood flow may be adjusted to
compensate for the flow diverted to the cardioplegia circuit (or
other circuits). This is done by monitoring the flow through
cardioplegia blood pump 35, and adding that much flow to arterial
pump 31 so that the flow to the patient remains the same. Assuming
a flow meter is not available, the flow displayed in sub-region 224
will be this calculated patient line flow.
[0208] The information set provided under the "Cardioplegia"
heading within sub-region 226 includes information corresponding
with monitored and preset values corresponding with the
cardioplegia mixture flowed through cardioplegia tubing line 156 to
a patient. Such parameters include the pressure of the cardioplegia
mixture (i.e., "Pressure"), the flow rate of the cardioplegia
mixture (i.e., "Flow") and the temperature of the cardioplegia
mixture (i.e., "Temp."). Such information is obtained via
monitoring signals received from pressure sensor 18, pumps 35 and
36 and temperature sensor 153. Again, the signals from pumps 35 and
36 reflect RPMs which can be employed with stroke volume-related
values for pumps 35 and 36 to determine cardioplegia flow rate, or
the flow rate from a flow meter may be displayed. Sub-region 226
also provides for the display of information relating to a
patient's coronary sinus pressure (i.e., "Coronary Sinus"). Such
pressure may be obtained from an auxiliary sensor connected to unit
10 or from a conventional operating room patient monitor
interconnected to unit 10. Additionally, sub-region 226 displays
values showing a target amount of cardioplegia mixture to be
delivered in a given increment (i.e., "Bolus"), the total amount of
cardioplegia delivered throughout the case (i.e., "Total"), and the
amount of time that has passed between cardioplegia delivery
periods (i.e., "Ischemic Time"). The "Ischemic Time" is
automatically determined by timing the interval between when pump
35 or 36, or both pumps 35 and 36, stop and subsequently
restart.
[0209] In the sub-region 228 corresponding with the "Blender"
heading, monitored and preset values are presented which pertain to
the flow of gas to the oxygenator 112. In particular, in the gas
circuit of FIG. 26, the flow rate of the gas supplied to the
oxygenator 112 is monitored by flow meter 356. Such amount may be
displayed in sub-region 228 (i.e., "Flow"). Further, the desired,
preset oxygen percentage for the inspired oxygen supplied to
oxygenator 112 is displayed (i.e., "FiO.sub.2"), and the desired
preset CO.sub.2 percentage of the inspired carbon dioxide supplied
to oxygenator 112 is displayed (i.e., "FiCO.sub.2"). Such
percentages may be displayed via signals provided to one or more of
the processors of unit 10 from valves 352a-352c in the gas circuit
shown in FIG. 26.
[0210] The "Other" sub-region 230 is provided to display other
monitored values and is re-configurable by a user. In FIG. 29, the
"Other" sub-region has been configured to display values
corresponding with a patient's arterial blood pressure (i.e.,
"Patient Arterial") and temperature ("Patient Temp."). Such values
may be monitored via an external system (e.g., an operating room
monitor) which is interconnected to the embedded processor in
control unit 10. Further, the monitored percentage of CO.sub.2 in
the expired oxygen passing out of oxygenator 112 may be displayed
(i.e., "FeCO.sub.2"). Such percentage may be provided by monitor
320 in the gas circuit shown in FIG. 26.
[0211] Tabbed Area:
[0212] The third region 240 of display 54 provides for the
selective display of various context-driven, information sets and
corresponding context-driven user-control options. During a bypass
procedure, such information sets and control options may be
navigated via selective contact with a plurality of context-driven
touch screen tabs, as will be further described.
[0213] Referring to FIG. 30A, when initiating a procedure, a first
tab 242 will present a title that changes in corresponding relation
to predetermined, pre-bypass steps to be completed. When these
steps are completed as described below, the first tab 242 will
present the title "Main" until bypass and post-bypass are complete,
when it will present the title "Unload". In addition to tab 242, a
plurality of other tabs may be selectively employed to access
different screen sets. As will be further described, tabs 244, 246,
248, 250, 252, and 254 are available for selection and use at any
time during setup or during bypass procedures and will illuminate
upon selection.
[0214] "A-V": Tab 244 may be employed to display a pictorial and/or
alphanumeric representation of and selectively control certain
control unit 10 functions relating to the venous and arterial
circuits, collectively, arterial-venous circuit. Additionally,
touch key buttons are displayed for immediate user control of
selected other functions.
[0215] "CPG": Tab 246 may be employed to a display pictorial and/or
alphanumeric representation of and selectively control certain
control unit 10 functions relating to the cardioplegia circuit,
e.g., including settings such as cardioplegia ratios or bolus
values. Additionally, touch key buttons are displayed for immediate
user control of selected other functions.
[0216] "Suction/Fluids": Tab 248 may be employed to display
pictorial and/or alphanumeric representations of and selectively
control certain control unit 10 functions relating to the suction
and left ventricular circuits. Additionally, touch key areas are
displayed for immediate user control of selected other functions,
including the addition of fluids through the prime lines.
[0217] "Gases": Tab 250 may be employed to display pictorial and/or
alphanumeric representations of and selectively control certain
control unit 10 functions relating to the gas circuit. By way of
example, tab 250 may be employed to establish the gas sweep rate
and/or defined FiO.sub.2 flow for oxygenator 112. Additionally, gas
combination ratios, relative concentration values and mass flow
rate relative to fluid flow rate may be established for gas circuit
340. For example, the user may establish a desired mixture of
O.sub.2/CO.sub.2, and air to be established at valves 352c, 352b,
and 352a. Additionally, tab 250 may be employed to present various
monitored gas pressure readings, including readings taken by
pressure sensors 360 and 364 comprising gas circuit 340.
[0218] "Waveforms": Tab 252 may be employed to display graphical
waveforms and trend settings, and alphanumeric representations,
including waveforms corresponding with patient pressure,
temperature and ECG signals received by the embedded processor from
external or internal systems.
[0219] "Settings": Tab 254 may be employed to display a pictorial
and/or alphanumeric representation of and selectively control
certain control unit 10 functions relating to the various system
parameter settings. Additionally, touch key buttons are displayed
for immediate user control of other parameter settings.
[0220] Main Tab: Tab 242 in region 240 is used to guide the
operator through a sequence of steps to setup, load, and prime the
tubing set, run the bypass procedure, run post-bypass steps, and,
finally, unload the tubing set. In this regard, the title of tab
242 changes to "User Setup", "Load", "Auto-Prime", "Main", and
"Unload" as the major steps of the procedure are executed, and
where "Main" covers both bypass and post-bypass operations.
[0221] Many of the operations encompassed by the Main tab are
sequential in nature, meaning that one step must be completed
before the next step(s) can be accomplished. Therefore, the screens
in tab 242 enforce this sequential nature by both the instructions
presented in message block 245, and by not "enabling" touch screen
buttons corresponding to later steps until the required
prerequisite steps are completed. A button that is not enabled does
nothing when touched, and also has a "dimmed out" look, where the
text on the button is in a gray color, rather than bright white as
exhibited on buttons that are "enabled". The figures discussed
below will illustrate this concept many times.
[0222] User Setup:
[0223] As noted above, upon initiating a procedure the first tab
242 will present a sequence of titles corresponding with certain
pre-bypass procedures to be completed. As illustrated in FIG. 30A,
the first such title to be presented by tab 242 is "User Set Up".
While the "User Set-Up" title is presented, the context-driven
portion 243 of the third region 240 presents information in both
graphic and narrative form regarding steps to be completed by a
user. In particular, in the embodiment shown in FIG. 30A, there are
seven set-up steps presented:
[0224] 1. "Insert oxygenator and venous reservoir in holders."
Together with this narrative a graphic depiction is provided
corresponding with venous reservoir 106 and oxygenator 112 (with
heat exchanger when used) to prompt a user to mount the reservoir
106 in mounting bracket 602 and to interconnect the oxygenator 112
to the bracket 500.
[0225] 2. "Snap in pre-bypass filter and venous entry module in
holders and place venous line in clamp and close cover." Together
with this narrative a graphic depiction is presented that
corresponds with venous entry module 108 and tubing line 104
positioned within venous line clamp 46, thereby prompting a user to
complete the tasks.
[0226] 3. "Insert cartridge and arterial filter in holders."
Together with this narrative instruction a graphic depiction is
presented corresponding with cartridge 120 to prompt a user to
mount the cartridge 120 in the loading assembly 21 provided in
component interface region 12, and prompting a user to place
arterial filter 118 in bracket 760 of component interface region
12.
[0227] 4. "Connect lines to A) arterial filter, B) venous entry
module, and C) venous reservoir (2)." Together with this narrative
a graphic depiction is presented corresponding with arterial filter
118, venous entry module 108, and venous reservoir 106, prompting
the user to connect oxygenator outlet line 116 to arterial filter
118, venous line 104 to venous entry module 108, purge tubing line
119b to venous reservoir 106, and tubing line 129 to filtered input
of venous reservoir 106.
[0228] 5. "Place line in bubble sensor and close cover." Together
with this narrative, a graphic depiction is presented corresponding
with bubble sensor 114, prompting the user to place tubing line 116
relative to bubble sensor 114.
[0229] 6. "Place arterial and cardioplegia table lines in clamps
and close covers." Together with this narrative, a graphic
depiction is presented corresponding with arterial valve block 196
and cardioplegia valve block 195, prompting the user to place
arterial patient line 122 relative to arterial valve block 196, and
cardioplegia to patient line 156 relative to cardioplegia valve
block 195.
[0230] 7. "Install pump loops and close all lids. Hang table pack
on console." Together with this narrative, a graphic depiction is
presented that corresponds with a tubing loop (e.g., 110, 178, 190,
180, 132 or 140) positioned within a pump assembly (e.g., 31, 32,
33, 34, 35 or 36), so as to prompt a user to complete all tubing
loop/pump installations.
[0231] As will be appreciated, the graphic depictions not only
prompt a user to complete a given step, but additionally facilitate
disposable component recognition and a ready review of the
necessary step.
[0232] Touch screen buttons found in the lower right corner of the
"Main" tab screens being defined here are known as "navigational"
buttons, in that they are used to navigate from one "Main" tab
screen to the next, or back again. In this regard, it should be
noted that the context portion 243 of the "User Set-Up" tab 242
comprises a message block 245 comprising the directive: "Follow
instructions and then press "Load" to go to Load screen."
Correspondingly, a navigational touch screen button 256a entitled
"Load" is provided that can be contacted by the user so as to
proceed from "User Set-Up" procedure step, to an "Auto-Load"
procedure step. The "Unload" navigational button may be used to
return the Unload screen shown in FIGS. 30K and 30L.
[0233] Load:
[0234] When the "Load" button 256a is pushed by user, the first tab
242 will present an "Auto-Load" title with the corresponding
procedure-related information presented in context portion 243, as
illustrated in FIG. 30B. In the context portion 243 of the
"Auto-Load" tab screen steps are contemplated, (where only the
first button 260b' is enabled initially):
[0235] 1. "Load Cartridge and oxygenator". Of note, this step is
presented in the form of a graphic button 260b' having touch screen
capabilities, wherein a user may simply contact the button 260b' so
as to cause cartridge 120 to be automatically retracted or loading
assembly 21 to be automatically advanced into operative relation
with the cartridge interface region 20, and to cause oxygenator 112
to be automatically retracted or moveable carriage member 511 to be
automatically advanced into operative relation with the stationary
face plate 510. In this regard, the message block 245 comprises the
directive "Press `Load cartridge and oxygenator` to automatically
load cartridge and oxygenator into system." While loading is
progressing, message block 245 may automatically display a series
of messages indicating the automatic configuration steps being
completed by control unit 10 (e.g., opening of valves, zeroing
pressure sensors, calibrating VLC 46). Block 245 may also include a
graphic, percent-of-completion or time-to-completion bar (called a
progress bar--see FIG. 30F for an example of one) that
automatically fills an outlined region in corresponding relation to
the degree of completion of task (e.g., as determined by a
comparison of elapsed time to a predetermined or predicted time for
completion). When this step is completed, a graphic check-mark will
be presented within the "Load Cartridge" button 260b' and the
"Pressure sensor zeroed, VLC set" box, so as to indicate to the
user that these steps have been successfully completed, and the
"Load pump loops" button 260b" is enabled, as shown in FIG.
30C.
[0236] 2. "Pressure sensor zeroed, VLC set". This narrative,
presented with a check mark, indicates that the steps described
have been successfully completed automatically upon completion of
the cartridge/oxygenator load process.
[0237] 3. "Check pump loops, close all lids". This narrative
corresponds with a tubing loop (e.g., 110, 178, 190, 180, 132 or
140) positioned within a pump assembly (e.g., 31, 32, 33, 34, 35 or
36), so as to prompt a user to check all tubing loop/pump
installations.
[0238] 4. "Load Pump Loops". Of note, this procedural step is
presented in the form of a loop touch screen button 260b". In this
regard, upon touching the "Load Pump Loops" button 260b" the
various tubing loops 110, 178, 190, 180, 132 and 140 will be
automatically loaded within the corresponding pumping assemblies
31, 32, 33, 34, 35 and 36, respectively. In this regard, while
automatic loading is being completed, message block 245 may include
the message "Loading Pump Loops." or other messages indicating the
progress of the pump loading and circuit test procedure.
Additionally, message block 245 may include a graphic progress bar
(as described above and illustrated in FIG. 30F) that automatically
fills an outlined region in corresponding relation to the degree of
completion of the task. When pump loading is completed, a graphic
checkmark will be presented within the Load Pump Loops button
260b", indicating completion of the task, as shown FIG. 30C.
[0239] 5. "Adjust Arterial pump to fully occluded for Prime."
Together with this narrative a pictorial graphic is presented with
content that prompts the user to adjust the occlusion setting wheel
on the arterial pump rotor to a position that is fully
occlusive.
[0240] As illustrated in FIGS. 30B-30C, the context portion 243 of
the "AutoLoad" screen tab includes a "Set-Up" graphic navigational
button 258b and a "Auto-Prime" graphic navigational button 256b
having touch screen functionality. The "Set-Up" button 258b is
provided to permit a user to return to the previously described
"Set-Up" tab screen shown in FIG. 30A. The "Auto-Prime" button 256b
allows a user to selectively proceed to the next pre-bypass
procedural step, but only after the various loading procedures
contemplated by FIGS. 30B-30C have been completed.
[0241] Auto-Prime:
[0242] As shown in FIG. 30D, the "Auto-Prime" tab screen includes a
context portion 243 that identifies the following procedural
steps:
[0243] 1. "Spike prime and cardioplegia bags." Together with this
narrative a corresponding graphic depiction is presented to
prompt/facilitate a user's interconnection of priming solution bags
162, and crystalloid bags 136 to the corresponding tubing lines
interconnected with cartridge 120.
[0244] 2. "Open water valves." Pressing this button causes the
valves connecting the temperature control systems 330 to the
oxygenator and cardioplegia heat exchangers to be opened. After a
press, the button changes to "Close water valves" (as shown in FIG.
30E) to allow the user to reverse the process.
[0245] 3. "Check oxygenator and cardioplegia heat exchangers for
water leaks." Together with this narrative a pictorial graphic is
presented with content that prompts a user to operate the
heater/cooler lines connected to oxygenator 112 (e.g., via ports
519a, 519b to insure there are no water leaks across the blood side
of oxygenator 112 via the heat exchanger thereof, and similarly for
the cardioplegia heat exchanger. The user must press the button
labeled "Pass" to confirm that there are no leaks, before the
"Start priming" button will be valid.
[0246] 4. "Start Priming." This procedural step is presented in the
form of a graphic touch screen button 260c'. Upon pushing the
button 260c' the various fluid circuits of disposable assembly 100
will be automatically primed with priming solution from bags 162
according to a predetermined protocol. Message block 245 may
display messages indicating the progress through the automated
priming algorithm steps, as seen in FIG. 30F. Additionally, message
block 245 may include a graphic progress bar that automatically
fills an outlined region in relation to the degree of completion of
the priming sequence steps, as seen in FIG. 30F. Upon completion of
such priming, a completion check-mark will be presented in the
middle of button 260c', as seen in FIG. 30G.
[0247] 5. "Check occlusion." Pressing this button starts the
Arterial pump occlusion setting assist algorithm, including
progress messages and progress bar in message block 245, as shown
in FIG. 30H.
[0248] 6. "Pre-Bypass Filter." Of note, this step is presented in
the form of a touch screen button 260c" that will be activated and
illuminated, or highlighted upon completion of step 4 noted above.
Upon pushing the illuminated button 260c" the control unit 10 will
automatically initiate pre-bypass filtering of the priming fluid
through the pre-bypass filter 168 according to a predetermined
protocol. Upon completion of such pre-bypass filtering, a
completion check-mark will be presented in button 260c".
[0249] Upon completion of step 6, the message block 245 will read:
"Pre-Bypass Filter completed, press `Bypass`." Correspondingly, a
user may proceed to bypass operations via pushing a graphic touch
screen navigational button 256c entitled "Bypass". Alternatively, a
user may go back to the prior step of "Auto-Load", by contacting
the graphic navigational button 258c presented. It should be noted
that if a user determines it necessary to proceed immediately to
bypass during pre-bypass procedures, the user may contact button
256c to interrupt the pre-bypass filtering and initiate bypass.
[0250] On Bypass:
[0251] Once the "Bypass" button 256c is pressed, the first tab 242
will present the title "Main" as shown in FIG. 30I. Thereafter, the
first tab 242 will continue to present the "Main" title in a
highlighted manner when selected, until the Unload screen is
activated.
[0252] As shown in FIG. 30I, "Main" tab 242 selection causes
context portion 243 to present narrative instructions in message
box 245 and to present graphic touch screen buttons and other
information in three rows entitled "System", "User Defined" and
"Timers". In particular, the narrative box 245 would normally start
with the following instruction:
[0253] "To begin Bypass, turn on the arterial flow".
[0254] At this point, the system is ready for bypass operations and
the user may proceed to interconnect the patient with the various
cannula assemblies that are interconnected with tubing line 104,
arterial patient blood line 122, cardioplegia tubing line 156 and
vent tubing line 186. Additionally, prior to or at this time
suction tubing lines 170 and 172 will be readied for use. The
patient's venous pressure will initiate the flow of venous blood
into tubing line 104 wherein the blood is then gravity drained to
venous reservoir 106. Alternatively, blood flow may be initiated
via the application of vacuum conditions at reservoir 106 or the
operation of an optional pump interfacing with venous tubing line
104. To initiate arterial, or oxygenated, blood flow to the patient
a user would need to manually start arterial pump 31 on control
unit 10 via use of the control knob 31a, or a pre-selected
automated start bypass procedure as will be further described.
[0255] The user may also select other operations. For example, and
as illustrated in FIG. 30I, the "System" row of graphic touch
screen buttons provide the following options:
[0256] "Pre-Bypass Filter." Of note, this step is presented in the
form of a touch screen button 262a. Upon pushing the illuminated
button 262a the control unit 10 will automatically initiate
pre-bypass filtering of the priming fluid through the pre-bypass
filter 168, by a predetermined protocol and the flow set by the
user using arterial pump speed knob 31a.
[0257] "System Recirc." button 262b: This button provides a user
with the ability to cause the recirculation of oxygenated blood
within the disposable assembly 100. When the button 262b is
activated, pump 31 will operate with valve 92 closed causing
oxygenated blood to recirculate in a closed loop through tubing
line 119a and 119b (for the FIG. 3A embodiment) reservoir 106,
oxygenator 112 and arterial filter 118. Such recirculation will
occur when the button 262b is graphically presented in a depressed,
or activated state, and will continue until the button 262b is
further contacted, whereupon the button will be presented in an
non-depressed, or inactive, state. By way of example, this option
may be utilized after set-up procedures, but prior to actual
cannula placement.
[0258] "Test Arterial Connection" button 262c: This button provides
the user with the ability to effect an automatic test of the
interconnection established between the cannula assembly
corresponding with tubing line 122 and a patient. When button 262c
is activated, with valve 92 opened and with pump 31 off, pressure
sensor 14 will sense a fluid pressure which should correspond with
the patient's blood pressure. As such, the user may compare the
sensed pressure value with a predetermined or monitored value or
range to determine if the patient interconnection is correct. A
user may momentarily operate pump 31 at a low rate while monitoring
the pressure sensed by sensor 14 to further insure proper
interconnection. Valve 92 must not be left open for an extended
period of time because there is a danger of draining the patient
through the under-occluded arterial pump. Therefore, button 262c
should operate as a press-and-hold (meaning valve 92 only stays
open while the user is holding button 262c down) and/or logic must
be included to automatically shut the valve after a predefined time
(e.g., 3-5 seconds).
[0259] The "System" row of buttons also includes the following
buttons:
[0260] "Patient Info." button 262d: This button provides the user
with the ability to immediately access a screen comprising specific
patient vital information (e.g., height, weight, name, patient ID
or social security number, lab data, etc.). In this regard, patient
information may be input/modified via touch screen functionalities
and/or interconnection of a keyboard to control unit 10.
[0261] "Log Event" button 262e: This button provides the user the
ability to access a screen for the input/display of specific events
which a user may want to keep track of during a procedure (e.g.,
drug delivery times/amounts). Again, the input of events may be
affected with touch screen capabilities and/or a keyboard or other
input device interconnected to control unit 10.
[0262] The "User Defined" row of graphic touch screen buttons may
comprise any of a number of features that may be pre-selected by a
user (e.g., via a "Settings" tab as described below). In the
embodiment shown in FIG. 30I the touch screen buttons provide a
user with the following control options:
[0263] "CPG Target" button 264a: This button provides the user with
the ability to set the amount of cardioplegia to be dispensed to a
patient during any given increment. Upon pushing the button 264a,
the button will be presented in a depressed, or activated state,
whereupon a user may then utilize control knob 52 to set the
desired amount of cardioplegia bolus to be delivered during the
given increment. When the desired amount is displayed in the middle
to button 264a, the user may again push button 264a or control knob
52 to exit the adjustment mode.
[0264] "CPG Delivery" button 264b' with "Reset" button 264b":
Button 264b' provides a user with the ability to initiate the
delivery of cardioplegia to a patient upon depression of button
264b'. When contacted, button 264b' will be graphically presented
in a depressed, or activated, state, and will effect the operation
of pump 36 or both pumps 35 and 36, to achieve the desired
cardioplegia mixture (i.e., of crystalloid and blood), as may be
pre-selected by a user. Additionally, when button 264b' is
activated, valve 96 will be opened. Cardioplegia will then flow to
a patient through tubing line 156 until the targeted bolus amount
set via use of control button 264a has been delivered, whereupon
cardioplegia delivery will be automatically stopped. The amount of
volume delivered (or yet to be delivered) will be displayed on the
control button, and also in the dedicated area. A user may also
manually stop cardioplegia delivery at any time by contacting
button 264b' or controlling knobs 35a and/or 36a of pumps 35 and
36, respectively. The amount of cardioplegia delivered during a
given increment will be displayed on an updated basis in the middle
of button 264b'. To reset the volume delivered display to a full
bolus amount (e.g., after the dispensation of an incomplete bolus
of cardioplegia), a user may push "Reset" button 264b". As shown in
FIG. 30I, an animated light indicator may be provided to indicate
when cardioplegia is being delivered (e.g., indicated via green
illumination) and when delivery is stopped (e.g., indicated via red
illumination).
[0265] "Test CPG Connection" button, when depressed, holds
cardioplegia patient line valve 96 open, so that distal pressure
may be read on cardioplegia pressure sensor 18. Valve 96 must not
be left open for an extended period of time because there is a
danger of draining the patient through the CPG patient line.
Therefore, button "Test CPG Connection" should operate as a
press-and-hold (meaning valve 96 only stays open while the user is
holding the button down) and/or logic must be included to
automatically shut the valve after a predefined time (e.g., 3-5
seconds).
[0266] "Cardioplegia Delivery Mode" region with "Antegrade" button
264c' and "Retrograde" buttons 264c": Buttons 264c' and 264c"
provide a user with the ability to select different alarm limits
for the pressure in tubing line 156 (e.g., via sensing by pressure
sensor 18) when cardioplegia is in either antegrade and/or
retrograde mode, respectively. In addition, the buttons may tell
the system to use a different pressure sensor for alarming and/or
limiting cardioplegia flow (e.g., use line pressure for Antegrade,
coronary sinus pressure for Retrograde).
[0267] The "Timers" row of graphic touch screen buttons can be
configured to provide a user with various display options. For
example, in the embodiment of FIG. 30I the following features are
presented:
[0268] "On Bypass" timer 266a': Timer 266a' provides for the
automatic display of a timed duration that a patient is on-bypass.
Timer 266a' may be automatically started when arterial pump 31 is
operated after priming and pre-bypass filtering with valve 92 open.
Timer 266a' will automatically stop when arterial pump 31 is
stopped, with valve 92 closed, and will automatically start again
when pump 31 is restarted with valve 92 open (e.g., with the timer
beginning where it left off). The user may also manually start the
On-Bypass timer simply by depressing button 266a', whereupon the
timer will start. To stop the timer, a user may inactivate button
266a' via contact. To reset the timer, a user may contact button
266a".
[0269] "X-Clamp" button 266b' and timer with "reset" button 266b":
Button 266b' provides a user with the ability to time the duration
the patient has been cross-clamped during a bypass procedure. To do
so, a user may simply depress button 266b', whereupon the timer
will start. To stop the timer, a user may inactivate button 266b'
via contact. To reset the timer, a user may contact button
266b".
[0270] "Off-Bypass" timer 266c': Timer 266c' may be provided to
provide a user with a timed duration display showing the amount of
time that a given patient has been off bypass. Timer 266c' may be
automatically started when valve 92 is closed, and may
automatically stop when valve 92 is reopened. Timer 266c' will
automatically reset when started again. The user may also manually
start the Off-Bypass timer simply by depressing button 266c',
whereupon the timer will start. To stop the timer, a user may
inactivate button 266c' via contact. To reset the timer, a user may
contact button 266c".
[0271] "Auxiliary" timer 266d' with "reset" button 266d": Button
266d' and reset button 266d" are provided to allow a user to
selectively time any given procedure being conducted during a
procedure. To initiate the timer, button 266d" may be contacted by
a user. To stop the timer, button 266d" may again be contacted so
as to deactivate the timer. To reset the time to zero, reset button
266d" may be contacted. When bypass is complete, the user may press
the navigational button
[0272] "Go to Post Bypass" to move to the Post-Bypass screen
described in FIG. 30J.
[0273] Post-Bypass:
[0274] As shown in FIG. 30J, "Main" tab 242 now shows the
Post-Bypass screen, which is similar to the Bypass except for the
User Defined row of buttons and the navigational buttons. The User
Defined buttons are defined as follows:
[0275] "Fill Patient" region with "Bolus" button 264d' and
"Deliver" button 264d": Button 264d' provides a user with the
ability to set a targeted amount of blood bolus to be dispensed to
a patient via tubing line 122. Upon contacting button 264d' a user
may utilize control knob 52 to establish the desired amount of
bolus to be delivered. The center of button 264d' will present the
selected amount. To exit the adjustment mode button 264d' may again
be pushed or control knob 52 may be pushed. In order to initiate
the delivery of a bolus amount, a user may simply contact button
264d". Button 264d" includes an illuminated display to show the
amount of bolus that has been delivered during a bolus delivery
period. To stop bolus delivery, a user may contact button 264d" so
as to trigger an inactive state. Alternatively, a user may manually
stop the delivery of bolus via manual stoppage of pump 31, or just
start/stop manually within using the bolus control logic.
[0276] "Chase" region operates similarly to Fill Patient, but
activates an additional algorithm whereby as fluid is removed from
the venous reservoir 108 the prime bag valves are opened to let
priming solution in to maintain the initial reservoir level (when
Chase was initiated), thereby "chasing" blood out of the reservoir
with saline.
[0277] "To Bags": This button adds an additional mode to the Fill
Patient and Chase modes, whereby instead of "filling" or "chasing"
blood down the arterial patient line 122, the arterial line valve
stays closed, and the user connects a transfer bag and/or
hemoconcentrator to the stopcock provided for such, and then the
system is "filling" or "chasing" blood to the
bag/hemoconcentrator.
[0278] The navigational button "Return to Bypass" will move back to
the Bypass screen described in FIG. 30I. The navigational button
"Move to Unloading" will move forward to the Unload screen
described in FIG. 30K.
[0279] Unload:
[0280] When the "Move to Unloading" button is pushed by user, the
first tab 242 will present an "Unload" title with the corresponding
procedure-related information presented in context portion 243, as
illustrated in FIGS. 30K-30L. In the context portion 243 of the
"Unload" tab screen steps are included:
[0281] "Clamp prime and cardioplegia bag lines." Together with this
narrative, a graphic depiction is provided corresponding with
crystalloid tubing lines 133 and prime bag lines 160 so as to
prompt a user to clamp off the bag lines before the cartridge is
disengaged from the platform.
[0282] "Remove pump loops." Together with this narrative, a graphic
depiction is presented that corresponds with a tubing loop (e.g.,
110, 178, 190, 180, 132 or 140) positioned within a pump assembly
(e.g., 31, 32, 33, 34, 35 or 36), so as to prompt a user to remove
all tubing loops from the pumps.
[0283] "Unload cartridge." Of note, this step is presented in the
form of a graphic button having touch screen capabilities, wherein
a user may simply contact the button so as to cause cartridge 120
to be automatically advanced away from the machine or loading
assembly 21 to be automatically retracted away from the cartridge
120, and to cause oxygenator 112 to be automatically advanced away
from the machine or moveable carriage member 511 to be
automatically retracted away from the stationary face plate 510. In
this regard, the message block 245 comprises the directive
"Complete steps below, then press `Unload cartridge and
oxygenator.`" While unloading is progressing, message block 245 may
automatically display a series of messages indicating the automatic
configuration steps being completed by control unit 10. Block 245
may also include a graphic progress bar that automatically fills an
outlined region in corresponding relation to the degree of
completion of task (e.g., as determined by a comparison of elapsed
time to a predetermined or predicted time for completion). When
this step is completed, a graphic check-mark will be presented
within the "Unload Cartridge and Oxygenator" button, so as to
indicate to the user that the step has been successfully completed,
as shown in FIG. 30L.
[0284] The navigational button "Post-Bypass" in FIG. 30K will be
presented before the cartridge is unloaded, to allow the user to
move back to the Post-Bypass screen in FIG. 30J. The button will be
hidden after the cartridge is unloaded (as shown in FIG. 30L),
unless it is reloaded by pressing "Unload cartridge" again.
[0285] The navigational button "Set-Up" in FIG. 30L will be
presented after the cartridge is unloaded, and allows the user to
move back to the beginning screen for a new case (FIG. 30A).
[0286] AV Tab:
[0287] As previously noted, the "A-V" tab 244 provides for the
pictorial depiction of components of the venous and arterial fluid
circuits and interfacing flow control and sensor components of
component interface region 12, as well as a plurality of touch
screen control buttons. As shown in FIG. 31A, the context driven
portion 243 of the "A-V" tab 244 comprises a column of touch screen
buttons 262a'-262e' in a first sub-region 267, and a fluid circuit
illustration in sub-region 268. Buttons 262a'-262e' provide for
direct user access to the same functionalities described above in
corresponding relation to buttons 262a-262e of FIG. 30I.
[0288] With particular reference to the fluid circuit sub-region
268, it can be seen that a number of graphic objects corresponding
with components of the arterial-venous circuit defined by
disposable assembly 100 are graphically depicted together with
graphic objects corresponding with selected flow control and
sensing components provided by component interface region 12. The
various graphic objects are presented with fluid flow lines
therebetween having arrowheads to indicate the direction of fluid
flow. The fluid flow lines are color-coded to indicate venous
circuit blood flow (e.g., indicated by use of blue fluid flow
lines) and arterial circuit blood flow (e.g., indicated by use of
red fluid flow lines). As will be further described, certain of the
graphic objects have touch screen functionality.
[0289] In particular, the objects entitled "Venous Assembly" 270a,
"Oxygenator" 270b, "Arterial Filter Assembly" 270c and "Air Shunt"
270d may be contacted by a user to provide additional detail
regarding the various corresponding components. More particularly,
FIG. 31B illustrates the further componentry that will be visually
represented upon contact with each of the three noted objects. Such
additional componentry is shown in FIG. 31B corresponding with
those described in relation to the disposable assembly 100 and
component interface region 12 descriptions hereinabove. Of note, it
can be seen that the pictorial representations corresponding with
various valve assemblies are illustrated in a manner that indicates
whether valve assemblies are in an open or closed state. Further in
this regard, it is important to note that the visual depictions of
at least some of the valve assemblies are provided with touch
screen functionality (e.g., as indicated by a three-dimensional
depiction), wherein upon contact with a given one of such graphic
representations, the corresponding valve assemblies within the
component interface region 20 will automatically change its open or
closed state to the opposite state (e.g., if opened upon contact
the flow control assembly will close), unless such change of state
would present a predetermined undesired condition in which case a
change of state would not be effected. In the latter case, a pop-up
window may appear describing why the change of state requested
would be undesirable, but also allowing the operator to override
this constraint and cause the valve to move anyway. Such
functionality provides a user with the capability to selectively,
manually control the flow of fluids through the system by
effectively interfacing only with display 54.
[0290] Level Pop-Up:
[0291] The venous reservoir object 270e corresponding with venous
reservoir 106 is also provided with touch screen functionality.
More particularly, FIG. 31C illustrates a pop-up interface window
272 that will be presented upon contact with the venous reservoir
object 270e. Such window may be utilized to establish the desired
level of fluid to be maintained in venous reservoir. Such pop-up
window 272 also allows a user to specify whether the desired level
is to be maintained by automatic operation of the arterial pump 31,
by the venous line clamp 46 within component interface region 20,
or by the vacuum regulator described in FIG. 11.
[0292] More particularly, as illustrated in FIG. 31C the pop-up
window 272 comprises the following touch screen buttons (one and
only one of the four level control buttons 272a, 272b, 272f, and
272g will be presented in a depressed state, to show the current
mode of level control):
[0293] "Art Pump" button 272a allows a user to readily select the
option of having the desired fluid level in venous reservoir 106
established or maintained via automatic operation of arterial pump
31. Upon activation, button 272a will be presented in a depressed
state. To deactivate, "Off" button 272g may be contacted so as to
turn level control off.
[0294] "VLC" button 272b allows a user to readily select the option
to have the desired fluid level in venous reservoir 106 established
or maintained by the automatic operation of venous line clamp 46.
Upon activation, button 272b will be presented in a depressed
state. To deactivate, "Off" button 272g may be contacted so as to
turn level control off.
[0295] "Vacuum" button 272f allows a user to readily select the
option to have the desired fluid level in venous reservoir 106
established or maintained by the automatic operation of the vacuum
regulator, when Vacuum-Assisted Venous Drainage (VAVD) is being
used. Upon activation, button 272f will be presented in a depressed
state. To deactivate, "Off" button 272g may be contacted so as to
turn level control off.
[0296] "Off" button 272g is used to stop level control by any
method. When no level control mode is active, button 272g will be
presented in a depressed state.
[0297] "Level control=reservoir level" button 272c allows a user to
automatically set the desired fluid level for reservoir 106 to be
whatever the then-current level is within reservoir 106. As such,
upon activation of button 272c, level sensor 87 in the component
interface region 12 of unit 10 will detect the current fluid level
in reservoir 106 and such fluid level will be utilized for purposes
of automatic operation of arterial pump 31 or venous line clamp
46.
[0298] "Settings" button 272d may be utilized by user as a shortcut
to a screen for establishing various sensor settings corresponding
with reservoir 106. For example, high level and low level settings
may be set by a user and monitored by the system to provide for
automated system response and the provision of alarm messages as
discussed hereinabove. The establishment of settings will be
further described hereinbelow.
[0299] Level control button 272e may be utilized by a user to
establish the desired fluid level to be maintained in reservoir
106. In particular, the user may activate 272e and then utilize
control knob 52 to raise or lower the level control point. As knob
52 is manipulated, the level control button 272e will go up and
down relative to reservoir 106 to provide a visual indication of
the desired level point. Additionally, the center of level control
button 272e will illuminate with the volume setting corresponding
with the position of the level control button 272e relative to
reservoir 106. Again, to exit adjustment mode, button 272e or
control knob 52 may be contacted.
[0300] Pressure Pop-Up:
[0301] If a pressure sensor is contacted on the graphic depictions
in these tabs, an associated pressure sensor pop-up window is
displayed. For example, if the arterial pressure sensor on FIG. 31B
is touched, the pop-up window shown in FIG. 31D is displayed. This
pop-up allows the user to see the pressure limit and control
settings, directly turn pressure control on or off for this sensor,
or go to the full pressure sensor settings page (FIG. 33D)
described hereinbelow by pressing the "Settings" button.
[0302] Temperature Pop-Up:
[0303] If a temperature sensor is contacted on the graphic
depictions in these tabs, an associated temperature sensor pop-up
window is displayed. For example, if the venous temperature sensor
on FIG. 31B is touched, the pop-up window shown in FIG. 31E is
displayed. This pop-up allows the user to see the temperature limit
settings, or go to the full temperature sensor settings page (FIG.
33E) described hereinbelow by pressing the "Settings" button.
[0304] Sat/Hct Pop-Up:
[0305] If the Sat/Hct sensor on FIG. 31B is touched, the pop-up
window shown in FIG. 31F is displayed. This pop-up duplicates the
front panel of the standalone Sat/Hct device, allowing the user to
standardize and calibrate the device, or go to the full Sat/Hct
sensor settings page (not shown) by pressing the "Settings"
button.
[0306] CPG Tab:
[0307] Referring now to FIG. 32A, CPG tab 246 and its corresponding
display are illustrated. As noted above, the CPG tab display
provides information relating to the cardioplegia circuit defined
by various components of the disposable assembly 100 as well as
interfacing components of component interface region 12. The
context region 243 of the CPG tab screen comprises a first
sub-region 267 that includes various touch screen, graphic buttons
and a second region 268 that provides a visual representation of
the cardioplegia circuit with objects corresponding with various
components of disposable assembly 100 and component interface
region 12 graphically represented. In this regard, it can be seen
that the circuit illustration region 268 comprises the following
graphic objects: "CPG Cardio Outlet Assembly" 274b and "Totals"
274c. Each of these objects may be contacted by a user to access a
more detailed illustration of pictorial presentations of
corresponding components of the disposable assembly 100 and
component interface region 20, as shown in FIG. 32B. The graphic
objects noted above are interconnected with fluid flow lines having
arrows indicating the direction of fluid flow therebetween. Such
fluid flow lines may be color coded in a manner to indicate the
type of fluid (e.g., yellow fluid flow line indicates crystalloid
and cardioplegia mixture flow and red fluid line indicates arterial
blood fluid flow).
[0308] As noted the CPG tab 246 shown in FIG. 32A also includes a
number of pictorial representations corresponding with various
components of the component interface region 20. Such pictorial
representations correspond with cardioplegia crystalloid pump 36,
cardioplegia blood pump 35, pressure sensor 18 and control valve
assembly 96. Valve assembly 96 representation is provided with
touch screen capabilities to permit opening and closing of valve 96
upon contact. The CPG tab screen shown in FIG. 32A may include
animated representations corresponding with cardioplegia
crystalloid bags 136. In this regard, the volume contents within
each of the bags 136 may be monitored on an on-going basis via
interface of the embedded processor with crystalloid pump 36
wherein volumetric contents may be represented graphically and
numerically in the pictorial representations of the crystalloid
bags 136.
[0309] Referring now to the first sub-region 267 shown in FIG. 32A,
it can be seen that a plurality of graphic object buttons are
presented. Several of these buttons correspond in type and
functionality with the second row of graphic object buttons
presented in the "Main" tab screen illustrated in FIG. 30I.
Additionally, of importance, a graphic button entitled "Ratio" 276
is presented which indicates the ratio of blood to crystalloid
solution to be established for the cardioplegia fluid delivered to
a patient utilizing the current settings. In the event that a user
would like to selectively change such ratio at any time, the
"Ratio" touch screen button 276 may be contacted and the user may
then utilize control knob 52 to increase or decrease the ratio to
the desired level (as shown in FIG. 32B), which will take effect
immediately if a bolus is currently in progress. Pushing in the
control knob 52 or pushing or touching another area on the touch
screen will exit the adjustment mode. Buttons 464a, 464b' and
464b", and 464c' and 464c", operate in the same functional manner
as described above in relation to buttons 264a, 264b' and 264b",
264c' and 264c", respectively. Further, the "Deliver Blood Only"
button in FIG. 32A allows the user to deliver cardioplegia blood
continuously (non-bolused) through only the cardioplegia blood pump
35, with no crystalloid added (non-ratioed), until the "Deliver
Blood Only" button is touched again to terminate the blood only
mode.
[0310] As noted above, the "CPG Cardio Outlet Assembly" object 274b
and "Totals" object 274c of the CPG tab screen shown in FIG. 32A
may be contacted by a user. FIG. 32B illustrates the additional
information that would be conveyed upon contact with each of the
two objects.
[0311] Suction/Fluids Tab:
[0312] Continuing now to FIG. 32C, the "Suction/Fluids" tab screen
and corresponding context driven display region 243 is presented.
Region 243 provides graphic representations corresponding with a
first suction tubing line 170 and corresponding pump 32, the second
suction line 172 and corresponding suction pump 34 and the left
ventricle tubing line 186 and corresponding pump 33, along with the
three negative pressure sensors associated with these three
suction/vent lines. Also depicted are the sequestration reservoir
and sequestration drain valve, the two valves that direct the vent
pump to either reservoir, and prime bags and associated prime bag
valves, and the reservoir filter pressure sensor.
[0313] In the alternative circuit embodiment shown in FIG. 3B, a
modified user interface could contain the following buttons (not
shown):
[0314] "Hemoconcentrator to Reservoir" button allows a user to
initiate automated hemoconcentration, wherein upon contacting the
button pumps 37 and 38 will operate at pre-selected rates to pump
the hemoconcentrated blood to reservoir 106.
[0315] "Hemoconcentrator to Transfer Bag" button allows a user to
initiate automated hemoconcentration, wherein upon contacting the
button pumps 37 and 38 will operate at pre-selected rates to pump
the hemoconcentrated blood to transfer bag 194.
[0316] "Transfer Bag to Reservoir" button allows a user to
selectively initiate the flow of fluid from transfer bag 194 to
reservoir 106.
[0317] "Reservoir to Transfer Bag" button: This button allows a
user to selectively effect the transfer of fluid from reservoir 106
to transfer bag 194.
[0318] "Off" button allows a user to stop any and all of the
functions associated with the four buttons listed above.
[0319] Gases Tab:
[0320] FIG. 32D illustrates the "Gases" tab 250 and a corresponding
context driven region 243. Again the context driven portion 243
includes a first sub-region 267 with a plurality of touch screen
buttons 468a-468c, and a second sub-region 268 which presents a
visual representation of a gas circuit servicing oxygenator
112.
[0321] Waveforms Tab:
[0322] FIG. 32E illustrates the "Waveforms" tab 252 and
corresponding context driven region 243. Again, the context driven
portion 243 includes a first sub-region 267 with a plurality of
touch screen buttons 282a-282c, and a second sub-region 268 which
presents a visual representation of one or more monitored
waveforms. More particularly, button 282a may be contacted to
access a screen which allows the user to select sensors for which
corresponding monitored waveforms are to be presented. The user may
select from a plurality of sensors, including for example, sensors
to monitor a patient's temperature, blood pressure and ECG
readings. Upon selection of a sensed parameter for waveform
presentation, the user may utilize buttons 282b and 282c to enlarge
and reduce, selectively, a given portion of the presented
waveforms.
[0323] FIG. 32E also shows a "Backward" button, that, for trending
waveforms, allows the user to display waveform activity earlier in
time than that currently shown, and a "Forward" button that allows
the user to return forward to the waveforms showing data currently
being collected.
[0324] Settings Tab:
[0325] Finally, FIGS. 33A-33F illustrate the "Settings" tab 254 and
corresponding context driven region 243 options accessible to a
user. In particular, the context-driven portion 243 shown in FIGS.
33A-33F includes a first sub-region 284 comprising a row of touch
screen buttons, and a second sub-region 286 which provides a
listing of further touch screen options corresponding with the
particular button 284a-284f within sub-region 284 that has been
contacted by user.
[0326] Protocol Settings:
[0327] For example, FIG. 33A shows a second sub-region 286 that
would be presented upon contact with the "Protocol" button 284a
presented in the first sub-region 284. A "Protocol" is a named,
stored set of all the parameter settings that may be established by
the user through the settings pages described hereinbelow. This
includes all sensor limit settings, configuration of user-defined
and configurable sections of the screen, and all other settings
from these screens. The "Current Protocol" item 286a at the top of
sub-region 286 indicates the name of the last protocol that was
established for current use ("Loaded"), and will also have a
asterisk next to it if any parameters settings have been modified
since the last protocol was loaded. Such setting modifications are
temporary, and will be overwritten if another (or the same) named
protocol is loaded. Such temporary settings may save into a new or
existing protocol with the "Save Protocol" control 286e described
below.
[0328] The touch screen options presented in the second sub-region
286 allow a user to select a protocol set to establish upon
power-up of the machine (the "Wake-Up" protocol 286b), establish a
different named protocol to be used currently ("Load Protocol"
286c), examine the details of any named protocol ("Display
Protocol" 286d), and save the current settings as a new named
protocol ("Save Protocol" 286e). Contacting the down arrow (286b',
286c', 286d', 286e') to right of each of these four controls
displays what is known as a "pull-down list", which drops down on
top of whatever is below, and provides a scrollable list of all
currently saved named protocols, including one or more "Factory
Default" protocols which are pre-set at the factory, and may not be
modified. Selecting a protocol from one of these four lists causes
the named protocol to be established as the Wake-Up protocol,
loaded as the current protocol, have its parameters displayed, or
be overwritten with the current parameter settings, respectively.
Additionally, the "Save Protocol" pull-down list will have an item
called "New", which, when selected, will allow the user to save a
new protocol, and give it a new name using an externally connected
or on-screen alphanumeric keyboard.
[0329] Sensor Settings:
[0330] In order to adjust individual component settings, a user may
contact one or more of the other buttons of the first sub-region
284. For example, upon contact with the "Sensors" button 284b
represented in the first sub-region, the options set forth in FIG.
33B will be presented. In this regard, and as shown in FIG. 33B,
the various sensors may be grouped as follows: "air detectors",
"pressure sensors", "level detectors", "blender/gas", "temp.
sensors" and "SAT/HCT". The various sensors that correspond with
each of these categories may be presented via contact with an
adjacent down arrow button, wherein a full listing of the various
sensors comprising a given group will be listed, each with
corresponding buttons. This is demonstrated in FIG. 33C with the
air detectors pull-down list. The user may then contact the graphic
button corresponding with a given sensor to establish the desired
settings. By way of example, FIG. 33D illustrates the display
accessible when a user contacts the button for "Arterial Line"
pressure sensor, and FIG. 33E illustrates the display accessible
when a user contacts the button for "Venous" temperature
sensor.
[0331] Pressure Sensor Settings:
[0332] As shown in FIG. 33D, a number of arterial pressure settings
can be established. In particular, the display corresponding with
FIG. 33D provides for establishing four different, predetermined
pressure settings to be monitored by pressure sensor 14. In order
to modify a given setting, a user may simply contact the
corresponding set button (e.g., the "low warning") button and then
establish the desired setting via control knob 52. As the control
knob 52 is adjusted, the corresponding pressure setting button will
move along the depicted pressure scale. When the desired pressure
setting has been reached, a user may again push the corresponding
pressure setting button or control knob 52. In addition to setting
the desired pressure levels, a user may further select from a
variety of sensor control functions as indicated by the various
touch screen buttons.
[0333] Temperature Sensor Settings:
[0334] As shown in FIG. 33E, a number of venous temperature
settings can be established. In particular, the display
corresponding with FIG. 33E provides for establishing high and low
alarm limit settings to be monitored by the venous temperature
sensor in venous entry module 108. Settings methods and options are
similar to those described for FIG. 33D.
[0335] As will be appreciated, similar screens may be provided for
establishing the settings of and control over the operation of the
various other types of sensors comprising control unit 10, and
generally noted by the groups indicated by FIG. 33B.
[0336] CPG Settings:
[0337] FIG. 33F-CPG Settings (accessed from CPG button 284c on
Settings tab FIG. 33A) gives the ability to specify the
constituents, starting volume, and default ratio for the
crystalloid bags, and change the bolus mode between volume, time or
continuous, count up or count down, as well as other settings.
[0338] More Settings (Not Shown):
[0339] Timers button 284d on Settings tab FIG. 33A accesses a Timer
Settings screen that gives timer on/off time/date tracking history,
and the ability to set timer alarms.
[0340] Pulse button 284e on Settings tab FIG. 33A accesses a
Pulsatile Flow Settings screen that lets the user set the Pulsatile
flow parameters for the arterial pump, such as BPM, duty cycle, and
baseline flow.
[0341] Other button 284f on the Settings tab FIG. 33A accesses a
Miscellaneous Settings screen that lets the user set the system
date and time, language to use, and other miscellaneous
settings.
[0342] VIII. Summary of Control Protocols and Algorithms
[0343] The perfusion system uses automated procedures described
below.
[0344] 1. Auto Prime
[0345] The "Auto-Prime" procedure, initiated by contacting graphic
button 260c' on the "Auto-Prime" tab screen shown in (FIG. 30D)
will result in the automatic priming of the venous, arterial and
cardioplegia fluid circuits. As will be appreciated, the automatic
priming will be controlled in accordance with predetermined
protocols stored in memory, and will entail automated steps.
[0346] Such steps will include the opening/closing of the priming
solution valves 98 so as to cause the priming solution to flow
through the integral passageway 164 of cartridge 120 and line 129
into the venous reservoir 106 and fill the venous reservoir 106 to
a predetermined volume. Operation of the arterial pump 31 and the
opening/closing of the various valve assemblies on control unit 10
will be completed according to the predetermined protocols so as to
prime line 110, oxygenator 112, line 116, arterial filter 118,
arterial patient line 122, venous patient line 104, venous entry
module 108, pre-bypass filter 168, line 166 and the air purge
tubing line 119a, integral passageways 309a and 309b of cartridge
120, and line 119b.
[0347] In this regard, it should be noted that the disposable
assembly 100 will initially provide for a fluid interconnect
between arterial patient tubing line 122 and venous tubing line
104, wherein the priming solution may flow through patient tubing
line 122, connector 175 and into venous tubing line 104. As will be
appreciated, venous line clamp 46 and valve assembly 95 may be
employed to direct the priming fluid through tubing lines 166 and
104 for priming purposes. Connector 175 will be disposed for
selective removal after priming when patient interconnect for
bypass is desired.
[0348] The automatic priming protocol will include inverting the
arterial filter 118 and reinverting the arterial filter 118 to the
up-right position multiple times during the priming sequence to
facilitate priming and removing air from the arterial filter. As
priming of the arterial filter 118 is initiated, the filter will be
inverted by rotating mounting arm 762 as previously described
herein such that the inlet from line 116 and air purge outlet
connecting to line 119a of the arterial filter is down, and the
outlet connecting to line 122 of the arterial filter is at the top.
During the bypass procedure the arterial filter inlet and air purge
outlet are located on the top of the arterial filter and the outlet
is located at the bottom of the arterial filter. As previously
described, initially during the automatic priming procedure the
arterial filter is inverted. Flow enters the arterial filter from
the inlet and due to the inverted positioning of the arterial
filter the flow fills the arterial filter from the bottom up
forcing air to naturally rise to the top of the arterial filter and
out the outlet of the arterial filter. At some point after the
arterial filter has been primed in the described manner the
arterial filter is reinverted to the up-right position where air in
the arterial filter can rise to the top and be purged out line
119a. The inverting and reinverting to the upright position is
repeated multiple times at high and/or low flow rates to ensure the
arterial filter is completely primed and air is removed.
[0349] Automatic priming will also entail the selective operation
of cardioplegia blood pump 35, cardioplegia crystalloid pump 36,
arterial pump 31 and the selective opening/closing of appropriate
valves comprising control unit 10 so as to direct priming solution
from venous reservoir 106 through tubing line 128, and integral
passageway 130. Such operation will effect priming of the
cardioplegia circuit portion including integral passageways 142,
and 150, tubing lines 146, cardioplegia heat exchanger 148, bubble
trap 152 as well as tubing loop 132. Similarly, the cardioplegia
tubing line 156 will be primed through connector 175 fluidly
interconnected with venous line 104 and returning fluid to venous
reservoir 106. Similarly, the cardioplegia crystalloid circuit
including crystalloid lines 133, integral passageways 138, and 142,
and tubing loop 140 will be primed with crystalloid solution.
[0350] 2. Pre-Bypass Filter
[0351] After the "Auto-Prime" procedures, a user may contact the
"Pre-Bypass Filter" button 260c" illustrated in (FIG. 30H), thereby
causing the priming solution present in the arterial-venous circuit
to be filtered via passage through pre-bypass filter 168 for a user
selected time at a user selected flow rate by operation of arterial
pump 31. In particular, valve 46 will close and valve 95 will open,
thereby diverting priming solution which flows into venous entry
module to flow through the pre bypass filter 168 and line 166 into
venous reservoir 106. The priming solution may then circulate from
venous reservoir 106 through tubing lines 110, 116, and 122, and
through the connector 175 that interconnects arterial patient line
122 and venous line 104, through venous entry module 108 and back
to pre-bypass filter 168.
[0352] Additionally, while pre-bypass filtering described herein
above, the cardioplegia blood pump 35 may be operated causing the
priming solution in the cardioplegia circuit to flow through
pre-bypass filter 168. In particular, cardioplegia blood pump 35
may be operated and valve 96 opened thereby causing the priming
solution to be diverted through line 128, integral passageways 130,
142, 150; tubing lines 146, pump tubing loop 132, cardioplegia
patient line 156, through connector 175, and into the venous line
104 for return to the pre-bypass filter 168.
[0353] 3. Start/Stop Bypass
[0354] To initiate bypass, the various cannula assemblies provided
on cardioplegia tubing line 156, venous tubing line 104 and
arterial tubing line 122 may be located as appropriate within the
body cavity of the patient.
[0355] Thereafter, to initiate actual bypass blood flow, venous
line clamp 46 may be manually operated by contacting graphic button
222a or button 222b and adjusting knob 52 to initiate and sustain
the necessary flow of venous blood through tubing line 104 to
venous reservoir 106. Arterial pump 31 may also be manually
operated by adjusting knob 31a and automatically or manually
opening valve 92 to initiate and sustain the necessary flow to
return blood to the patient through arterial patient line 122.
[0356] Additionally, while a user may start or stop a bypass
procedure via manual control of venous line clamp 46 and arterial
pump 31 and valve 92, a user may initiate an automatic start or
stop bypass procedure. The automatic start procedure, initiated
and/or enabled by contacting a graphic button (not shown) on user
interface 50, will result in the automatic start of the arterial
pump 31 and/or the automatic opening of the venous line clamp 46.
As will be appreciated, the automatic start procedure will be
controlled in accordance with predetermined protocols stored in
memory, and will entail automated steps. The control unit 10 may
then begin automated start or automated stop of the bypass
procedure if the procedure is currently in progress. For example,
at the outset of bypass, the starting up of arterial pump 31 is
controlled according to a predetermined ramp rate protocol. Such
ramp rate, the speed or flow increase per unit time, may be
selected by a user by contacting graphic buttons (not shown) and/or
adjustment of knob 52 on user interface 50 tab 254. Similarly, at
the outset of bypass, the opening of the venous line clamp 46 may
occur according to a predetermined ramp rate protocol stored in
memory after contacting a graphic button (not shown) on user
interface 50. Such ramp rate, the opening rate per unit time, may
be selected by a user by contacting graphic buttons (not shown)
and/or adjustment of knob 52 on user interface 50.
[0357] The automatic/manual operation described herein above of the
venous line clamp 46 and arterial pump 31 to start bypass may occur
in any combination. More specifically bypass may be initiated by
manual operation of both the venous line clamp 46 and arterial pump
31, manual operation of the venous line clamp 46 with automatic
operation of the arterial pump 31, automatic operation of the
venous line clamp 46 with manual operation of the arterial pump 31,
or automatic operation of both the venous line clamp 46 and
arterial pump 31.
[0358] The manual/automatic methods herein described above to start
bypass may be similarly used to stop the bypass procedure. More
specifically, the venous line clamp 46 may be manually operated to
reduce or terminate the flow of blood from the patient and the
arterial pump 31 may be manually operated to reduce or terminate
the flow of blood to the patient as necessary to stop bypass.
Similarly, the automatic means to start bypass through the
automatic operation of the venous line clamp 46 and the arterial
pump 31 may be used to stop bypass using the ramp methods described
herein above to reduce or terminate the blood flow to or from the
patient as necessary to stop bypass. The manual and automatic ramp
methods of operating the venous line clamp 46 and arterial pump 31
described herein above to start or initiate bypass may also be used
in the same combinations as described herein above to reduce or
terminate flow as necessary to stop bypass.
[0359] 4. Auto Start/Stop Bypass Using Venous Line Clamp to Control
Venous Reservoir Level
[0360] This is a method of either starting or stopping bypass while
maintaining the venous reservoir 106 level at a pre-selected value
through increasing or decreasing the amount of restriction of the
venous line 104 using venous line clamp 46 control. More
specifically, prior to initiating bypass, the user would select the
desired venous reservoir level to maintain while starting bypass by
contacting graphic buttons (not shown) and/or adjusting knob 52 on
user interface 50. The pre-selected venous reservoir level could be
set to the current reservoir level, or a reservoir level either
above or below the current level as desired by the user. The venous
line clamp reservoir level control procedure, initiated and/or
enabled by contacting a graphic button (not shown) on user
interface 50, will result in venous reservoir level control by
automatic opening or closing of venous line clamp 46. As will be
appreciated, the automatic level control will be controlled in
accordance with predetermined protocols stored in memory, and will
entail automated steps.
[0361] As bypass is started, the user would manually operate the
arterial pump 31 to begin bypass flow and slowly or quickly
increase flow to the user desired flow rate. While the user started
flow by increasing the speed through operation of knob 31a on
arterial pump 31, the venous line clamp 46 would automatically
begin to open to the amount necessary to maintain the venous
reservoir 106 level at the pre-selected value. As the venous
reservoir level fluctuates either due to adjustment of the arterial
pump 31 flow rate or due to other volumetric changes in the patient
or bypass circuit, venous line clamp 46 would automatically
increase or decrease the amount of restriction in venous line 104
to either increase or decrease the flow into the venous reservoir
to maintain the venous reservoir level at the pre-selected
value.
[0362] Conversely, in order to stop bypass, the venous line clamp
reservoir level control procedure, initiated by contacting a
graphic button (not shown) on user interface 50, will result in
venous reservoir level control by automatic opening or closing of
venous line clamp 46. Prior to stopping bypass, the user would
select the desired venous reservoir level to maintain while
stopping bypass by contacting graphic buttons (not shown) and/or
adjusting knob 52 on user interface 50. While the user decreases
the flow by reducing the arterial pump flow rate through operation
of the knob 31a on arterial pump 31, the venous line clamp 46 would
automatically begin to close to the restriction necessary to
maintain the venous reservoir 106 level at the pre-selected value.
As the venous reservoir level fluctuates either due to continued
slow down of the arterial pump 31 flow rate or due to other
volumetric changes in the patient or bypass circuit, venous line
clamp 46 would automatically decrease or increase the amount of
restriction in venous line 104 to either increase or decrease the
flow into the venous reservoir to maintain the venous reservoir
level at the user pre-selected value.
[0363] 5. Auto Start/Stop Bypass Using Arterial Pump to Control
Venous Reservoir Level
[0364] This is a method of either starting or stopping bypass while
maintaining the venous reservoir 106 level at a pre-selected value
through increasing or decreasing the flow into and out of venous
reservoir 106 through automatic control of arterial pump 31 flow
rate. More specifically, prior to initiating bypass, the user would
select the desired venous reservoir level to maintain while
starting bypass by contacting graphic buttons (not shown) and/or
adjusting knob 52 on user interface 50. The pre-selected venous
reservoir level could be set to the current reservoir level, or a
reservoir level either above or below the current level as desired
by the user. The arterial pump reservoir level control procedure,
initiated and/or enabled by contacting a graphic button (not shown)
on user interface 50, will result in venous reservoir level control
by automatic increasing or decreasing flow of arterial pump 31. As
will be appreciated, the automatic level control will be controlled
in accordance with predetermined protocols stored in memory, and
will entail automated steps.
[0365] As bypass is started, the user would manually begin to open
venous line clamp 46 to begin bypass flow and slowly or quickly
increase venous flow to the user desired flow rate. While the user
started flow by decreasing the restriction in venous line 104
through manual operation of venous line clamp 46, the arterial pump
31 would automatically begin to increase flow to the amount
necessary to maintain the venous reservoir 106 level at the
pre-selected value. As the venous reservoir level fluctuates either
due to adjustment of venous line clamp 46 or due to other
volumetric changes in the patient or bypass circuit, arterial pump
31 would automatically increase or decrease the amount of flow 104
to either increase or decrease the flow out of the venous reservoir
to maintain the venous reservoir level at the pre-selected
value.
[0366] Conversely, in order to stop bypass, the arterial pump
reservoir level control procedure, initiated by contacting a
graphic button (not shown) on user interface 50, will result in
venous reservoir level control by automatic increasing or
decreasing flow by operation of arterial pump 31. Prior to stopping
bypass, the user would select the desired venous reservoir level to
maintain while stopping bypass by contacting graphic buttons (not
shown) and/or adjusting knob 52 on user interface 50. While the
user decreases the flow into the venous reservoir 106 by reducing
the restriction in venous line 104 through manual operation of the
venous line clamp 46, the arterial pump 31 would automatically
begin to reduce flow to the amount necessary to maintain the venous
reservoir 106 level at the pre-selected value. As the venous
reservoir level fluctuates either due to continued restriction of
venous line 104 through operation of venous line clamp 46 or due to
other volumetric changes in the patient or bypass circuit, arterial
pump 31 would automatically decrease or increase the flow exiting
venous reservoir 106 to maintain the venous reservoir level at the
pre-selected value.
[0367] 6. Cardioplegia Pressure Protection
[0368] The "Cardioplegia Pressure Protection" procedure, initiated
and/or enabled by contacting a graphic button (not shown) on user
interface 50 will result in the automatic control of cardioplegia
pumps 35, 36 to prevent negative pressure occurring on oxygenator
112. As will be appreciated, the automatic cardioplegia pressure
protection procedure will be controlled in accordance with
predetermined protocols stored in memory, and will entail automated
steps.
[0369] If enabled, the cardioplegia pressure protection procedure
may provide an automated monitoring function, wherein if the
pressure in the arterial tubing line 122, as monitored by pressure
sensor 14 falls below a predetermined low limit, the cardioplegia
blood pump 35 and/or crystalloid pump 36 will automatically slow
down while maintaining their respective flow rate ratios such that
the flow of the cardioplegia blood pump 35 does not cause the
pressure in line 122 as monitored by pressure sensor 14 to fall
below a predetermined low pressure limit. Alternatively, if the
pressure monitored by pressure sensor 14 falls below a
predetermined low limit, the cardioplegia blood pump 35 and/or
crystalloid pump 36 will automatically stop. Such automatic control
reduces the risk that a negative pressure will act upon the
membrane within the oxygenator 112 so as to introduce air into the
arterial blood. If the pressure monitored by pressure sensor 14
falls below a predetermined low pressure limit an alarm will occur
on user interface 50.
[0370] 7. Cardioplegia-Arterial Pump Interlock
[0371] The "Cardioplegia-Arterial Pump Interlock" procedure,
initiated and/or enabled by contacting a graphic button (not shown)
on user interface 50 will result in the automatic control of
cardioplegia pumps 35, 36 to prevent negative pressure occurring on
oxygenator 112. As will be appreciated, the automatic
cardioplegia-arterial pump interlock procedure will be controlled
in accordance with predetermined protocols stored in memory, and
will entail automated steps.
[0372] If enabled, the cardioplegia-arterial pump interlock
procedure may provide an automated monitoring function, wherein if
the arterial pump stops or slows to a flow rate below the flow rate
of the cardioplegia blood pump 35, the cardioplegia blood pump 35
and/or the crystalloid pump 36 may stop. Alternatively, if the
arterial pump stops or slows to a speed or flow rate below the flow
rate of the cardioplegia blood pump 35, the cardioplegia blood pump
35 and/or the crystalloid pump 36 may slow down to a combined flow
rate, while maintaining their respective flow rate ratios, such
that the cardioplegia blood pump 35 flow rate is less than the
arterial pump flow rate 31. Such automatic control reduces the risk
that a negative pressure will act upon the membrane within the
oxygenator 112 so as to introduce air into the arterial blood.
[0373] 8. Post Bypass Fluid Recovery
[0374] Upon completion of a bypass procedure, additional automated
operations may be completed. For example, specific protocols may be
followed to recover as much usable blood as possible from the fluid
circuits. Such procedures may include the drainage of blood from a
sequestration reservoir 301 into venous reservoir 106 via selective
control over valve 401 by contacting a graphic button (not shown)
on user interface 50. Additionally, a user may drain blood from the
venous tubing line 104 into the venous reservoir 106 by opening
venous line clamp 46 by contacting graphic buttons (not shown)
and/or adjusting knob 52 on user interface 50. Cardioplegia blood
pump 35 and arterial pump 31 may also be selectively operated in
reverse by contacting graphic buttons (not shown) on user interface
50 resulting in the automatic operation of cardioplegia blood pump
35 and arterial pump 31 and cardioplegia patient line valve 96. As
will be appreciated, the procedure will be controlled in accordance
with predetermined protocols stored in memory, and will entail
automated steps by contacting graphic buttons (not shown) on user
interface 50 as to empty the cardioplegia circuit blood through
integral passageway 130 to tubing line 128, arterial filter 118,
tubing lines 116 and 118, and back into the venous reservoir 106.
The collected body fluid may then be diverted to a transfer bag
through valve 311 or through line 122 or through connection
directly to an autologous blood salvage device for subsequent
washing for later return to the patient.
[0375] 9. Sequestration Level Sensing
[0376] The "Sequestration Level Sensing" procedure, initiated
and/or enabled by contacting a graphic button (not shown) on user
interface 50, will result in the automatic control of suction and
vent pumps 32, 33, and 34 and/or sequestration drain valve 401 to
prevent over filling of the sequestration reservoir. As will be
appreciated, the automatic sequestration level sensing procedure
will be controlled in accordance with predetermined protocols
stored in memory, and will entail automated steps.
[0377] If enabled, the sequestration level sensing procedure may
provide an automated function. If the lower level sensor 322
detects fluid an advisory alarm occurs to alert the user that the
level in sequestration reservoir 301 is rising. The user may then
open drain valve 401 and empty the contents through integral
passageway 305 and tubing line 129 into the venous reservoir 106 or
drain off contents to a transfer bag or cell washing device through
manual valve 303.
[0378] If the higher level sensor 320 detects fluid an advisory
alarm occurs at user interface 50 indicating that sequestration
reservoir 301 is full. The sequestration drain valve 401
automatically opens causing the contents of sequestration reservoir
301 to flow into venous reservoir 106 until the fluid level drops
below the lower level sensor 322 or until all suction pumps are
stopped. Alternatively, if the operator prefers that the
sequestered blood not be automatically added to the venous
reservoir, the suction pumps 32 and 43 could be selectively stopped
automatically. The vent pump 33 could also be automatically stopped
or the fluid re-routed to the venous reservoir 106 through integral
passageway 192b and line 129 by opening valve 403 and closing valve
402.
[0379] The user options described herein above could be selected by
contacting graphic buttons (not shown) on user interface 50 to
enable the desired options.
[0380] 10. Automatic Air Shunt
[0381] The "Automatic Air Shunt" procedure will result in the
automatic shunting of air through automatic control of arterial
pump 31 and valves 405 and 406 to remove air from the circuit and
prevent air from entering the patient. As will be appreciated, the
automatic air shunt procedure will be controlled in accordance with
predetermined protocols stored in memory, and will entail automated
steps.
[0382] When a predetermined small amount of air (i.e., small amount
of air is a given volume of air in a given amount of time where
most of the air would flow through the air shunt circuit line 119a,
integral passageways 309a and optionally 309b and line 119b without
a significant amount of air entering the arterial filter then
transiting the arterial filter medium and exiting the arterial
filter), is detected at oxygenator bubble sensor 114 the high flow
arterial filter purge valve 406 and optionally the low flow
arterial filter purge valve 405 opens and the air/fluid is routed
through line 116, arterial filter 118, line 119a, integral
passageways 309a and/or 309b, line 119b to venous reservoir 106. An
alarm condition will be generated and displayed on user interface
50. Valve 406 and optionally valve 405 remain open until a
predetermined amount of time after no air is present at the bubble
sensor 114 to ensure that all air is removed from the circuit.
[0383] When a predetermined large amount of air (i.e., large amount
of air is a given volume of air in a given amount of time that
would exceed the amount of air that could flow through the air
shunt circuit line 119a, integral passageways 309a and optionally
309b and line 119b resulting in a significant amount of air
entering the arterial filter and transiting the arterial filter
medium then exiting the arterial filter and potentially into the
arterial patient line 122), or a continuous amount of small air is
detected at oxygenator bubble sensor 114 the high flow arterial
filter purge valve 406 and optionally low flow arterial filter
purge valve 405 opens and the air/fluid is routed through line 116,
arterial filter 118, line 119a, integral passageways 309a and/or
309b, line 119b to venous reservoir 106. Additionally, arterial
pump 31 slows to a flow that will not generate a pressure that
exceeds a predetermined value as seen at pressure sensor 114 and
valve 92 is closed. An alarm condition will be generated and
displayed on user interface 50. After a predetermined amount of
time after no air is present at bubble sensor 114 valves 406 and
optionally valve 405 close. After the air condition has cleared,
valve 92 is opened and arterial pump speed returns to the pre-air
flow rate either automatically or manually by the user.
Alternatively, instead of slowing down arterial pump 31, arterial
pump 31 may be stopped and valve 92 closed.
[0384] In each case where the arterial pump 31 is slowed or stopped
and valves 405 and 406 opened or closed, the user can override the
automated procedure by contacting graphic buttons (not shown) on
user interface 50 which returns the arterial pump and/or valves to
their pre automatic air shunt condition settings.
[0385] If the arterial line pressure as measured at pressure sensor
14 is not sufficiently high enough to prevent retrograde flow of
air through purge valves 405 and 406, valves 405 and 406 could be
closed if the arterial line pressure falls below a predetermined
value.
[0386] In addition, when air is detected at bubble sensor 114 blood
cardioplegia delivery is automatically interrupted to prevent air
from reaching the cardioplegia system if the amount of air exceeds
a predetermined amount that could transition the arterial filter
and potentially enter the cardioplegia blood supply line 128.
[0387] 11. Automatic Fill Patient
[0388] The "Automatic Fill Patient" procedure, initiated and/or
enabled by contacting graphic button 264d" on user interface 50
will result in the automatic control of arterial pump 31 and
arterial patient line valve 92 to deliver preselect volume to the
patient. As will be appreciated, the automatic fill patient
procedure will be controlled in accordance with predetermined
protocols stored in memory, and will entail automated steps. The
user would select the desired volume to transfer to the patient by
contacting graphic buttons (not shown) and/or adjusting knob 52 on
user interface 50.
[0389] If enabled, this protocol automatically returns fluid to the
patient at a user-selected bolus volume and flow rate at the end of
the procedure. The user initiates the auto fill procedure by
touching the 264d" button at the user interface 50. This
automatically causes arterial line valve 92 in arterial patient
line 122 to open and arterial pump 31 to run at the user-selected
flow rate set at control knob 31a. After the selected bolus volume
is delivered the arterial pump 31 stops and valve 92 is closed. As
the bolus is delivered, the current, and/or accumulated amount can
be displayed on user interface 50.
[0390] 12. Positive and Negative Pressure Control
[0391] The "Pressure Control" procedures, initiated and/or enabled
by contacting a graphic button (not shown) on user interface 50
will result in the automatic control of any pump to control the
pressures in the respective pump circuits. As will be appreciated,
the pressure control procedures will be controlled in accordance
with predetermined protocols stored in memory, and will entail
automated steps. The user would select the desired pressure control
settings by contacting graphic buttons (not shown) and/or adjusting
knob 52 on user interface 50.
[0392] This control protocol is useful to control pressure in
various circuits in the perfusion system by controlling pump speed.
This control algorithm may be used in any pump circuit. This is
more desirable than stopping the pumps on an overpressure condition
since a complete stop of the pump results in completely stopping
fluid flow in the circuit and potentially creating vastly
fluctuating pressures.
[0393] This control protocol allows the pump to be controlled to a
speed lower than its user-set speed in order to control to a
programmable set point pressure. This pressure set point may be
either positive (for arterial or cardioplegia pumps) or negative
(for suction or vent pumps). The maximum pump speed is the user-set
speed at pump knobs 31a-36a. The pump will run at this speed unless
the measured pressure increases over the set point pressure (or
decreases below the set point for negative pressure control.). When
measured pressure exceeds set point pressure a pressure control
loop is enabled. Use of this control algorithm requires a pressure
transducer calibrated in appropriate units, having an appropriate
sample rate (i.e., 40 Hz).
[0394] The monitored pressure is used as a feedback control
parameter to automatically adjust pump speed to maintain pressure
at the control point. In the event the monitored pressure falls
outside of user set limits an alarm/indication may be provided at
interface 50 and/or the speed of one or more (e.g., both
cardioplegia pumps simultaneously) is either increased or decreased
in order to maintain the desired pressure. For example, the user
may set at the user interface a high pressure limit of 150 mmHg, a
low pressure limit of 20 mmHg and a control point of 100 mmHg. By
utilizing the monitored pressure as a feedback control parameter
the system will automatically adjust the speed of the pumps to
maintain pressure at the control point. If the pressure exceeds for
any reason the upper or lower limit an alarm is activated at the
user interface.
[0395] 13. Venous Reservoir Level Control by Arterial Pump
[0396] The venous reservoir level control by arterial pump
procedure, initiated and/or enabled by contacting a graphic button
(not shown) on user interface 50 will result in the automatic
control of arterial pump 31 to maintain the desired level or volume
in the venous reservoir. As will be appreciated, the level control
procedure will be controlled in accordance with predetermined
protocols stored in memory, and will entail automated steps. The
user would select the desired venous reservoir level to maintain by
contacting graphic buttons (not shown) and/or adjusting knob 52 on
user interface 50.
[0397] This control protocol maintains the level in the venous
reservoir 106 at a pre-selected value by controlling the speed of
arterial pump 31. The continuous level control is an operational
mode by which the level of the reservoir is not allowed to increase
above or decrease below the pre-selected value which can be
adjusted by the user. Use of this mode requires that a continuous
level sensor such as that described with respect to FIG. 12 is
present on the system to provide feedback of the current level of
fluid in the reservoir. The pump's maximum flow rate is set by the
user at pump knob 31a. As the level increases above or decreases
below the pre-selected value, a software and/or hardware
implemented PID (Proportional, Integral, Differential) servo slows
the pump down or speeds up the pump and adjusts the pump speed to
maintain the pre-selected reservoir level resulting in the flow
rate out of the reservoir closely matching the flow into the
reservoir. If the flow into the reservoir increases substantially,
then the level may rise above the set point because the pump flow
rate is limited by the setting of the pump knob 31a.
[0398] The advantage of this method of level control is that the
level in the reservoir can be controlled to any level. The level
can also be changed at any time and there will be a smooth
transition between the old and new levels. Use of the pump
continuous level control system also increases patient safety
because it will prevent emptying of the venous reservoir 106 in
case of temporary user inattention.
[0399] 14. Venous Reservoir Level Control by Venous Line Clamp
[0400] The venous reservoir level control by venous line clamp
procedure, initiated and/or enabled by contacting a graphic button
(not shown) on user interface 50 will result in the automatic
control of venous line clamp 46 to maintain the desired level or
volume in the venous reservoir. As will be appreciated, the level
control procedure will be controlled in accordance with
predetermined protocols stored in memory, and will entail automated
steps. The user would select the desired venous reservoir level to
maintain by contacting graphic buttons (not shown) and/or adjusting
knob 52 on user interface 50.
[0401] This control protocol maintains the level in the venous
reservoir 106 at a pre-selected value by controlling the venous
line clamp 46. The continuous level control is an operational mode
by which the level of the reservoir is not allowed to decrease
below or increase above some pre-selected value which can be
adjusted by the user. Use of this mode requires that a continuous
level sensor such as that described with respect to FIG. 12 is
present on the system to provide feedback of the current level of
fluid in the reservoir. As the level increases above or decreases
below the pre-selected value, a software and/or hardware
implemented PID (Proportional, Integral, Differential) servo
partially or completely opens or closes venous line clamp 46 to
maintain the pre-selected reservoir level resulting in the flow
rate into the reservoir closely matching the flow out of the
reservoir.
[0402] The advantage of this method of level control is that the
level in the reservoir can be controlled to any level. The level
can also be changed at any time and there will be a smooth
transition between the old and new levels. Use of the venous line
clamp continuous level control system also increases patient safety
because it will prevent emptying of the venous reservoir 106 in
case of temporary user inattention.
[0403] 15. Venous Reservoir Level Control by Venous Reservoir
Vacuum
[0404] The venous reservoir level control by venous reservoir
vacuum procedure, initiated and/or enabled by contacting a graphic
button (not shown) on user interface 50 will result in the
automatic control of venous reservoir vacuum to maintain the
desired level or volume in the venous reservoir. As will be
appreciated, the level control procedure will be controlled in
accordance with predetermined protocols stored in memory, and will
entail automated steps. The user would select the desired venous
reservoir level to maintain by contacting graphic buttons (not
shown) and/or adjusting knob 52 on user interface 50.
[0405] This control protocol maintains the level in the venous
reservoir 106 at a pre-selected value by controlling the level of
vacuum in the venous reservoir. Typically, vacuum level control
would most likely be used when vacuum is already in use for vacuum
assisted venous drainage procedures in order for vacuum to have an
effect on increasing or lowering level. The continuous level
control is an operational mode by which the level of the reservoir
is not allowed to decrease below or increase above some
pre-selected value that can be adjusted by the user. Use of this
mode requires that a continuous level sensor such as that described
with respect to FIG. 12 is present on the system to provide
feedback of the current level of fluid in the reservoir. As the
level increases above or decreases below the pre-selected value, a
software and/or hardware implemented PID (Proportional, Integral,
Differential) servo increases or decreases the vacuum in the venous
reservoir to maintain the preselected reservoir level resulting in
the flow rate into the reservoir closely matching the flow out of
the reservoir. If vacuum is not currently in use in the venous
reservoir, the ability to reduce vacuum to lower the reservoir
level would not exist. In this case vacuum reservoir level control
would only be one sided whereby vacuum could only be added and used
to increase the level in the reservoir level.
[0406] The advantage of this method of level control is that the
level in the reservoir can be controlled to any level. The level
can also be changed at any time and there will be a smooth
transition between the old and new levels. Use of the venous
reservoir vacuum continuous level control system also increases
patient safety because it will prevent emptying of the venous
reservoir 106 in case of temporary user inattention.
[0407] 16. Automatic Fluid Shuttling
[0408] The automatic fluid shuttling procedure, initiated and/or
enabled by contacting a graphic button (not shown) on user
interface 50 will result in the automatic control of venous line
clamp 46 to transfer a preselected volume of fluid to or from the
bypass circuit to the patient during bypass. As will be
appreciated, the automatic fluid shuttling procedure will be
controlled in accordance with predetermined protocols stored in
memory, and will entail automated steps. The user would select the
desired volume to transfer by contacting graphic buttons (not
shown) and/or adjusting knob 52 on user interface 50.
[0409] To transfer fluid to the patient, the system control
automatically senses the current level in the venous reservoir 106
and causes the venous line clamp 46 to reduce flow by restricting
the venous line and/or the arterial pump to increase flow by
increasing the pump speed until the selected volume has been
transferred to the patient. Either the venous line clamp 46 setting
or the arterial pump 31 flow setting mode is selectable by the user
by contacting graphic buttons (not shown) and/or adjusting knob 52
on user interface 50. At completion of the volume transfer the
venous line clamp and/or the arterial pump will return to their
previous settings. To transfer fluid from the patient, the system
control automatically senses the current level in the venous
reservoir and causes the venous line clamp 46 to increase flow
and/or the arterial pump 31 to decrease flow until the selected
volume has been transferred from the patient. The venous line clamp
46 setting or the arterial pump 31 flow setting, which ever mode
was used, will return to the previous settings after completing the
volume transfer.
[0410] 17. Variable Minimum Reservoir Level
[0411] The variable minimum reservoir level control procedure,
initiated and/or enabled by contacting a graphic button (not shown)
on user interface 50 will result in the automatic control of
arterial pump 31 to a safe flow rate to prevent emptying the venous
reservoir and ensure that air is not introduced into the venous
reservoir outlet line. As will be appreciated, the variable minimum
reservoir level procedure will be controlled in accordance with
predetermined protocols stored in memory, and will entail automated
steps.
[0412] To ensure the venous reservoir 106 is not emptied when
operating at lower levels in the venous reservoir and to ensure
that air is not introduced into the venous reservoir outlet line
110 due to high flow rates causing air generation from vortexing or
entrained air to enter the venous reservoir outlet, the arterial
pump 31 flow is automatically reduced as the venous reservoir level
decreases. Typically, the automatic slow down of arterial pump 31
occurs at levels below 200 mt to 500 mt. For example, as the venous
reservoir level decreases below 200 mt, the arterial pump would
begin to reduce flow to a safe flow rate. As the level in the
reservoir continues to decrease, the arterial pump flow would also
continue to decrease flow until the safe flow rate for that level
in the reservoir is reached. The safe flow rate for the arterial
pump 31 at a given venous reservoir level is based on determining
the current volume in venous reservoir 106, and determining the
time it would take to safely stop the arterial pump (i.e., how fast
the arterial pump 31 can be stopped without emptying the venous
reservoir) and determining the maximum operable flow rate where air
would be prevented from entering the venous reservoir outlet tubing
110 due to vortexing or air entrainment. From the venous reservoir
level, the time required to safely stop the arterial pump, and the
maximum operable flow rate for a given level, the safe arterial
pump flow rate for a given venous reservoir level can be
determined.
[0413] The advantage of using this low level slow down technique is
that the arterial pump flow rate is reduced depending upon the
reservoir level and there are no abrupt stops and starts of the
arterial pump. This smoother control helps improve safety with less
chance of entraining air into the venous reservoir outlet tubing
110.
[0414] Existing systems that do not have an available continuous
level sensor cannot provide an equivalent form of pump slow down at
low reservoir levels. A discreet single level sensor, used on some
perfusion systems, can only provide a pump shut down at that level,
with the possibility of reverting to some sort of oscillation of
the pump around that level.
[0415] Alternatively, a system using two discreet level sensors
could be used to provide a form of level control to maintain level
between the locations of these two sensors. The control point is
then fixed and no advanced slow down of the pump is possible using
this configuration as described above but the arterial pump flow
could be increased or reduced to keep the venous reservoir level
essentially between the two discrete level sensors.
[0416] 18. Auto Arterial Line Clamp With Arterial Pump Stop
[0417] The automatic arterial line clamp with arterial pump stop
procedure, initiated and/or enabled by contacting a graphic button
(not shown) on user interface 50 will result in the automatic open
or close arterial line clamp 92 if arterial pump 31 is started or
stopped. As will be appreciated, the automatic line clamp procedure
will be controlled in accordance with predetermined protocols
stored in memory, and will entail automated steps.
[0418] This protocol may automatically close the arterial line
clamp 92 in arterial line 122 when arterial pump 31 is stopped.
This prevents draining the patient through the under occluded pump
or possibly drawing air through the cannula purse strings if
arterial pump 31 is stopped. Conversely, arterial line clamp 92 in
arterial line 122 may open when arterial pump 31 is started.
[0419] 19. Auto Venous Line Clamp With Arterial Pump Stop
[0420] The automatic venous line clamp with arterial pump stop
procedure, initiated and/or enabled by contacting a graphic button
(not shown) on user interface 50 will result in the automatic open
or close of venous line clamp 46 if arterial pump 31 is started or
stopped. As will be appreciated, the automatic venous line clamp
procedure will be controlled in accordance with predetermined
protocols stored in memory, and will entail automated steps.
[0421] This protocol may automatically close venous line clamp 46
in venous line 104 when arterial pump 31 is stopped. This prevents
exsanguination of the patient or overflowing the venous reservoir
106 if arterial pump 31 was stopped and venous line clamp 46 was
left open. Conversely, venous line clamp 46 in venous line 104 may
open when arterial pump 31 is started.
[0422] 20. Automatic Cardioplegia Delivery
[0423] The automatic cardioplegia delivery procedures herein
described below, initiated and/or enabled by contacting graphic
buttons (not shown) on user interface 50 will result in the
automatic control of cardioplegia circuit pumps and valves to
facilitate delivery of cardioplegia delivery solutions. As will be
appreciated, the automatic cardioplegia delivery procedures will be
controlled in accordance with predetermined protocols stored in
memory, and will entail automated steps. The user would select the
cardioplegia delivery parameters by contacting graphic buttons (not
shown) and/or adjusting knob 52 on user interface 50.
[0424] In one automatic cardioplegia delivery procedure, the
cardioplegia patient valve 96 and pre-selected crystalloid solution
valve 99 can be automatically opened when delivery begins (i.e.,
when cardioplegia pumps 35 and or 36 are operated) and both the
cardioplegia patient valve 96 and the pre-selected crystalloid
solution valve 99 can be automatically closed when delivery stops
(i.e., when cardioplegia pumps 35 and 36 are stopped).
[0425] In another cardioplegia automated feature, the user can
pre-select different ratios for each of the cardioplegia
crystalloid bags 136. During cardioplegia delivery, control unit 10
will automatically invoke the pre-selected ratio for the respective
crystalloid bag 136 selected for delivery to the patient.
[0426] Additionally, cardioplegia may be automatically delivered to
the patient by either volume delivery (i.e., where a pre-selected
bolus volume is delivered to the patient and when the pre-selected
volume is delivered, cardioplegia delivery is terminated) or time
delivery (i.e., where a cardioplegia bolus is delivered for a
pre-selected amount of time and at the end of the pre-selected
time, cardioplegia delivery is terminated) or cardioplegia may be
delivered manually where the user manually starts cardioplegia
until a volume or time has expired and whereby the user manually
terminates cardioplegia delivery.
[0427] Additionally, cardioplegia crystalloid valves 99 can be
alternately opened and closed while operating crystalloid pump 36
to allow variable concentration, fixed dilution delivery. The first
crystalloid valve 99 is opened to draw in a specific volume of
crystalloid solution containing a first set of constituent
ingredients. Then the second valve 99 is opened to draw in a second
specific volume of crystalloid solution second set of constituent
ingredients. Typically, the two crystalloid solutions contain one
or more different constituent ingredients whereby the mixing of the
two crystalloid solutions at the pre selected proportions will
yield the desired concentrations for cardioplegia delivery. The
proportion of the volumes drawn from each crystalloid bag 136
determines the resultant crystalloid constituent
concentration(s).
[0428] 21. Vacuum Assisted Venous Drainage (VAVD)
Feedback/Control
[0429] During vacuum assisted venous drainage the vacuum is used to
augment the venous return from the patient to ensure there is
adequate flow from the patient to maintain the patient on bypass.
When flow rates are reduced during the procedure while moving or
filling the heart, at the end of the procedure, or any other
reason, the vacuum may not be necessary to maintain flow and may
create unsafe vacuum levels on circuit components which may cause
air to enter the patient circuits.
[0430] The automatic vacuum assisted venous drainage (VAVD)
feedback/control procedure, initiated and/or enabled by contacting
a graphic button (not shown) on user interface 50 will result in
the automatic control of the venous reservoir vacuum pump or
pressure regulator to prevent adverse effects of vacuum on various
circuit components. As will be appreciated, the automatic vacuum
assisted venous drainage (VAVD) feedback/control procedure will be
controlled in accordance with predetermined protocols stored in
memory, and will entail automated steps.
[0431] To prevent the possibility of negative effects from the
vacuum, such as creating a negative pressure acting on the
oxygenator membrane and drawing air across membrane into the blood
lines, the vacuum can be reduced or stopped through control of a
vacuum regulator (not shown) or vacuum pump (not shown) as the
arterial pump 31 flow is reduced. Once the system detects the
arterial pump 31 is slowing down, the vacuum can be reduced to
maintain the level in the reservoir. This control method is similar
to venous reservoir level control with vacuum as previously
described herein.
[0432] Additionally, if arterial pump 31 is stopped the venous
reservoir vacuum can be turned off to ensure negative pressure is
not applied to the oxygenator or other circuit elements that may
not operate properly under negative pressure. In addition to
turning the vacuum off control unit 10 can also vent the venous
reservoir to atmosphere to quickly relieve the vacuum in the venous
reservoir through the operation of a vacuum regulator or valve (not
shown).
[0433] Additionally, if positive pressure is created in the venous
reservoir for example due to a malfunction of a passive pressure
relief valve, the positive pressure can be automatically released
by the vacuum regulator or valve (not shown) to prevent pressure
build up inside the venous reservoir as the pressure exceeds a
predetermined value.
[0434] 22. Automatic Hemoconcentration
[0435] The automatic hemconcentration procedures herein described
below, initiated and/or enabled by contacting graphic buttons (not
shown) on user interface 50 will result in the automatic control of
hemoconcentrator pumps and valves to facilitate hemoconcentration.
As will be appreciated, the automatic hemoconcentration delivery
procedures will be controlled in accordance with predetermined
protocols stored in memory, and will entail automated steps. The
user would select the hemoconcentration parameters by contacting
graphic buttons (not shown) and/or adjusting knob 52 on user
interface 50.
[0436] A two pump hemoconcentration system as described previously
with respect to FIG. 3B uses a blood inflow pump 37 to the
hemoconcentrator and a blood outflow pump 38 from the
hemoconcentrator. It has a pressure monitor 86 on the
hemoconcentrator blood inlet. The pressure sensor monitors the
inlet pressure to ensure the pressure does not exceed a
predetermined value where an alarm would occur on user interface 50
and/or both the inflow and outflow pumps could be slowed or
stopped. There is also a valve 39 on the waste line which is closed
during a portion of the priming sequence to prevent the prime
solution from being passed through the hemoconcentrator and later
opened to allow priming across the hemoconcentrator membrane or the
valve could be used to provide a restriction on the
hemoconcentrator effluent line to reduce effluent flow. Effluent
rate and volume could be precisely controlled and determined by
controlling the inflow and outflow pump flow rates. The inflow pump
flow rate would be greater than the outflow pump flow rate to
ensure air is not drawn into the hemoconcentrator circuit across
the hemoconcentrator membrane. The effluent rate or ultrafiltrate
rate equals the difference between inflow and outflow blood pump
rates. The control unit 10 could automatically operate both pumps
at respective flow rates to deliver a user selected effluent rate
or a user selected effluent volume in a user selected period of
time. A scale could be added on the ultrafiltrate waste bag to
weigh the effluent to determine the effluent volume.
[0437] Alternatively, the outflow pump could be replaced with a
variable restrictor valve (not shown) on the blood out flow line
from the hemoconcentrator to change the transmembrane pressure
(TMP) which is the driving force of the effluent across the
hemoconcentrator membrane. Restricting the valve would increase
TMP, subsequently increasing effluent rate and opening the valve
would decrease TMP, subsequently decreasing effluent rate.
[0438] Additionally, a hematocrit sensor (not shown) could be added
in the circuit to measure the hematocrit at the outlet of the
hemoconcentrator. The control unit 10 could use the outlet
hematocrit information and the inlet hematocrit information as
measured at hematocrit sensor 85 or only the hemoconcentrator
outlet hematocrit to feedback to and automatically adjust the
hemoconcentrator inlet and outlet flow rate to yield a user
selected hematocrit of the blood exiting the hemoconcentrator.
[0439] 23. Correct Pump Load and Circuit Test
[0440] This is a series of automatic tests performed by control
unit 10 in conjunction with disposable assembly 100 to determine if
the pump headers are loaded properly, if the suction, vent and
cardioplegia pumps are fully occluded, and if the arterial pump is
overoccluded or underoccluded.
[0441] The automatic pump load and circuit test procedures herein
described below, may be automatically initiated during or after
disposable load and/or priming will result in the automatic
operation of any pump or valve to test the disposable assembly for
proper loading and or function. As will be appreciated, the
automatic pump load and circuit test procedures will be controlled
in accordance with predetermined protocols stored in memory, and
will entail automated steps. The user would select the user
settable pump load and circuit test parameters by contacting
graphic buttons (not shown) and/or adjusting knob 52 on user
interface 50.
[0442] After loading disposable assembly 100 on control unit 10 the
suction and vent pumps can be automatically operated to test for
correct loading or for leaks in their respective circuits. The
patient lines 170, 172 and 186 of these circuits are sealed by
connection to plugs or some other connector or connectors that seal
the ends of lines 170, 172, and 186. The sealing may occur during
assembly of disposable assembly 100 or the lines could be clamped
by the user during the test. The test is performed by operating the
two suction pumps and vent pump at a predetermined or user selected
speed or flow rate over a predetermined or user selected time
period. As the pumps are operated a vacuum is generated in the
suction and vent circuits and measured at pressure sensors 40, 42,
and 44 until a predetermined pressure is reached where the
respective pumps are stopped. If a positive pressure is generated
this indicates the pump tubing lines 178, 180, and 190 are probably
loaded incorrectly (i.e., reversed) and an alarm occurs advising
the user of the condition and any appropriate checks or corrective
actions that should occur. If the predetermined pressure cannot be
reached during the predetermined test time period this indicates a
leak exists in the circuit and an alarm occurs advising the user of
the test failure which may include advisory messages in checking
for the leak or resolution of the problem. If the predetermined
pressure is reached the pumps are stopped and a pressure decay test
is performed which monitors the pressure at sensors 40, 42, and 44
and if a predetermined pressure loss over a predetermined time
occurs a leak may exist in the circuit and an alarm occurs advising
the user of the test failure and any appropriate checks or
corrective actions that should occur. If the pressure at sensors
40, 42, and 44 reach the predetermined pressure limit and no
significant pressure decay occurs, the circuit is not leaking, the
pump tubing has been loaded correctly and the pump is fully
occlusive on the pump tubing.
[0443] A similar test is performed on the cardioplegia circuit. For
the cardioplegia circuit the cardioplegia patient valve 96 is
closed and the pumps (35, 36) are operated at a predetermined flow
one pump at a time which creates a positive pressure in the circuit
to a predetermined pressure as measured at pressure sensor 18. If
the predetermined pressure cannot be reached during the
predetermined test time period this indicates a leak exists in the
circuit and an alarm occurs advising the user of the test failure
which may include advisory messages in checking for the leak or
resolution of the problem. If the predetermined pressure is reached
the pumps are stopped and a pressure decay test is performed which
monitors the pressure at sensor 18 and if a predetermined pressure
loss over a predetermined time occurs a leak may exist in the
circuit and an alarm occurs advising the user of the test failure
and any appropriate checks or corrective actions that should occur.
If the pressure at 18 reaches the predetermined pressure limit and
no significant pressure decay occurs, the circuit is not leaking,
the pump tubing has been loaded correctly and the pump is fully
occlusive on the pump tubing. This test is repeated for the second
cardioplegia pump. The test is performed one cardioplegia pump at a
time because the two pumps share the same outlet connection which
if the two pumps are operated simultaneously they may mask a small
leak.
[0444] The arterial-venous circuit (A-V circuit) could be checked
in a similar manner as herein described once the arterial circuit
has been primed. The circuit requires priming because air alone
would not hold pressure since the pressure would leak across the
oxygenator membrane. The test would be conducted in a similar
manner as described herein with similar alarm messages.
[0445] Alternatively, a pressure sensor (not shown) could be added
to the A-V circuit on the outlet of the arterial pump 31 between
the arterial pump and the oxygenator 112 and a valve (not shown)
could be added and positioned downstream of the pressure sensor
just described. Using this pressure sensor and valve, a similar
circuit pressure test as previously described herein for the
cardioplegia pumps could be performed to check for circuit leaks,
correct loading of the tubing line and pump occlusion in the A-V
circuit.
[0446] After auto prime, the system may be checked for leaks by
closing various valves, and operating various pumps in various
combinations and monitoring respective pressures and pressure decay
rates and providing alarms advising the user of circuit or
equipment problems if the predetermined pressure limits are not
reached or the pressure decay rates exceeded.
[0447] Additionally, by pressurizing the priming solution in the
oxygenator to a predetermined value, leaks in the membrane can be
detected with the liquid leak detector 366 shown on FIG. 26 as
fluid would transverse a leaky oxygenator membrane at a
predetermined pressure.
[0448] 24. Arterial Pump Occlusion Setting Assist
[0449] The automatic pump occlusion setting assist procedures
herein described below, initiated and/or enabled by contacting the
graphic "check occlusion" button on user interface 50 will result
in the automatic control of arterial pump 31 and valves 92, 405 and
406 while monitoring pressure at pressure sensor 14 to aid in
setting the arterial pump occlusion. As will be appreciated, the
automatic pump occlusion setting assist procedures will be
controlled in accordance with predetermined protocols stored in
memory, and will entail automated steps. The user would select the
user settable parameters by contacting graphic buttons (not shown)
and/or adjusting knob 52 on user interface 50. The occlusion check
normally occurs after priming but could occur after loading
disposable assembly 100 and before prime.
[0450] After initiation of the automatic pump occlusion setting
assist, arterial patient line valve 92, and purge valves 405, 406
are closed and arterial pump 31 is operated at a predetermined
speed for a predetermine time. If the arterial pump outlet pressure
as measured at pressure sensor 14 exceeds a predetermined pressure
value, the pump is stopped and purge valves 405 and/or 406 are
opened to release the pressure and the occlusion is determined to
be over occluded. The user is advised through user interface 50 of
the overoccluded condition and the user is instructed to reduce the
occlusion by a predetermined amount and to repeat the test by
contacting the check occlusion button (#) on user interface 50. If
the predetermined pressure value is not reached, the average
pressure is calculated. If the average pressure is greater than a
second predetermined pressure value, the user is instructed to
reduce the occlusion by a predetermined amount and to repeat the
test by contacting the check occlusion button on user interface 50.
If the average pressure is less than a third predetermined pressure
value, the user is instructed to increase the occlusion by a
predetermined amount. If the average pressure is between the second
and third pressure values, the occlusion setting is determined to
be acceptable and the user is advised of that on user interface 50.
The occlusion test is repeated until the pressure is in the
predetermined acceptable range or the user ends the test.
[0451] A polynomial is used to determine the occlusion adjustment
amount for both reducing or increasing occlusion for an over
pressure condition or under pressure condition respectively.
[0452] Alternatively, a method of measuring occlusion is to close
the arterial line valve 92 and the purge valves 405 and 406, then
operate arterial pump 31 until a predetermined pressure has been
reached. The arterial pump is then stopped and the pressure decay
(i.e., pressure drop over a period of time) is determined by
recording the measured pressure at pressure sensor 14 at
predetermined time intervals. A decay rate of a predetermined range
of values would result in an acceptable occlusion. A decay rate
exceeding the predetermined decay rate range of values would
indicate an underocclusion setting and the user would be instructed
to increase occlusion as described herein above. A decay rate less
than the predetermined decay rate range of values would indicate an
over occlusion setting and the user would be instructed to decrease
occlusion as described herein above.
[0453] 25. Arterial Pump Occlusion Setting Methods Using the
Cardioplegia Blood Pump.
[0454] The automatic pump occlusion setting assist procedures
herein described below, initiated and/or enabled by contacting a
graphic "check occlusion" button on user interface 50 will result
in the automatic control of cardioplegia blood pump 34 and valves
92, 405 and 406 while monitoring pressure at pressure sensor 14 to
aid in setting the arterial pump occlusion. As will be appreciated,
the automatic pump occlusion setting assist procedures will be
controlled in accordance with predetermined protocols stored in
memory, and will entail automated steps. The user would select the
user setable parameters by contacting graphic buttons (not shown)
and/or adjusting knob 52 on user interface 50. The occlusion check
normally occurs after priming but could occur after loading
disposable assembly 100 and before prime.
[0455] The cardioplegia blood pump 34 can be operated in reverse,
pumping fluid backwards through the under-occluded arterial pump,
while monitoring the arterial line pressure as measured at pressure
sensor 14 and with arterial patient valve 92, purge valves 405 and
406 all closed. The flow rate and pressure generated would indicate
the occlusion as in a similar manner as previously described
herein.
[0456] Alternatively, the cardioplegia blood pump can be operated
in the forward direction, with the arterial pump pumping at a
predetermined RPM and the arterial outlet line clamped. The speed
of the cardioplegia blood pump can be varied to maintain a constant
pressure in the arterial line as measured at pressure sensor 14.
The difference between the predicted arterial pump flow at full
occlusion and the cardioplegia pump flow rate would be the leakage
rate due to under-occlusion. (A positive pressure must be
maintained to prevent air passing across the oxygenator
membrane.)
[0457] The description provided above is strictly for exemplary
purposes. Numerous modifications, extensions and adaptations of the
present invention will be apparent to those skilled in the art upon
consideration, and are intended to be within the scope of the
present invention.
* * * * *