U.S. patent application number 10/461939 was filed with the patent office on 2004-02-19 for integrated medication delivery system.
Invention is credited to Staunton, Doug, Toman, Jason.
Application Number | 20040034331 10/461939 |
Document ID | / |
Family ID | 46299432 |
Filed Date | 2004-02-19 |
United States Patent
Application |
20040034331 |
Kind Code |
A1 |
Toman, Jason ; et
al. |
February 19, 2004 |
Integrated medication delivery system
Abstract
A medication delivery system includes a reservoir for storing a
supply of medication and a pump assembly coupled to the reservoir.
The pump assembly has a pump inlet and a pump outlet and is
controllable to provide a flow of medication in the form of a
series of pulses. The pump outlet is subdivided into a plurality of
legs. A controller is coupled to the pump assembly for controlling
the pump assembly and receives a desired flow of medication and
responsively controls the pump assembly to provide a series of
pulses of medication to provide the desired flow of medication. The
series of pulses are determined to provide an outlet pressure at
the pump outlet adapted to reduce an effect of any differential
pressure between the legs.
Inventors: |
Toman, Jason; (Portage,
MI) ; Staunton, Doug; (Kalamazoo, MI) |
Correspondence
Address: |
HOWARD & HOWARD ATTORNEYS, P.C.
THE PINEHURST OFFICE CENTER, SUITE #101
39400 WOODWARD AVENUE
BLOOMFIELD HILLS
MI
48304-5151
US
|
Family ID: |
46299432 |
Appl. No.: |
10/461939 |
Filed: |
June 13, 2003 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
10461939 |
Jun 13, 2003 |
|
|
|
10083266 |
Feb 23, 2002 |
|
|
|
60271187 |
Feb 23, 2001 |
|
|
|
60451161 |
Feb 28, 2003 |
|
|
|
Current U.S.
Class: |
604/500 ;
604/151 |
Current CPC
Class: |
A61M 5/1684 20130101;
A61M 39/223 20130101; A61M 5/16854 20130101; A61M 39/16 20130101;
A61M 5/16881 20130101; A61M 5/14228 20130101; A61M 5/14216
20130101; A61M 5/14244 20130101 |
Class at
Publication: |
604/500 ;
604/151 |
International
Class: |
A61M 031/00; A61M
001/00 |
Claims
What is claimed is:
1. A medication delivery system, comprising: a reservoir for
storing a supply of medication; a pump assembly being coupled to
the reservoir and having a pump inlet and a pump outlet, the pump
assembly being controllable to provide a flow of medication in the
form of a series of pulses, the pump outlet being subdivided into a
plurality of legs; and, a controller coupled to the pump assembly
for controlling the pump assembly, the controller receiving a
desired flow of medication and responsively controlling the pump
assembly to provide a series of pulses of medication to provide the
desired flow of medication, wherein the series of pulses are
determined to provide an outlet pressure at the pump outlet adapted
to reduce an effect of any differential pressure between the
legs.
2. A medication delivery system, as set forth in claim 1, wherein
the controller determines a period of time between a start of each
pulse, wherein the period of time is determined such that each
pulse begins before a predetermined drop in fluid pressure level
occurs.
3. A medication delivery system, as set forth in claim 1, wherein
the series of pulses includes first and second groups of pulses, a
start of each pulse within each group being separated by a first
period of time and a start of the first pulse in each group being
separated by a second period of time.
4. A medication delivery system, as set forth in claim 3, wherein
each group has a predetermined number of pulses.
5. A medication delivery system, as set forth in claim 4, wherein
the controller determines the second period as a function of the
desired fluid flow.
6. A medication delivery system, as set forth in claim 1, wherein
the pump assembly includes: a motor; a cam shaft coupled to the
motor; and, first and second pinch levers in engagement with the
cam shaft.
7. A medication delivery system, as set forth in claim 6, wherein
each of the first and second pinch levers comprise a cam follower,
said cam followers being engaged by said cam shaft for alternating
movement of said first and second pinch levers between said open
and closed positions such that the medication can be delivered to
the patient.
8. A medication delivery system, as set forth in claim 7, wherein
the pump assembly further includes a piston, the motor moving the
piston to draw the medication into the pump assembly when the first
pinch lever is in the open position and the second pinch lever is
in the closed position, and to displace the medication from the
pump assembly when the first pinch lever is in the closed position
and said second pinch lever is in the open position.
9. A medication delivery system, as set forth in claim 1, further
comprising a multiple site infusion apparatus coupled between the
pump outlet and the legs.
10. A medication delivery system, as set forth in claim 9, wherein
the multiple site infusion apparatus includes: a valve housing
having a first end and a second end, the first end including first
and second outlet orifices; and, a flexible diaphragm coupled
between the cap and the valve housing and being movable from a
closed position to and open position, the flexible diaphragm
sealing the pressure chamber from the first and second outlet
passageways when in the closed position and opening the first and
second passageways to the pressure chamber when in the open
position, the second end of the valve housing and the flexible
diaphragm forming a pressure chamber, the valve housing further
including an inlet passageway coupled to the pressure chamber and
at least one outlet passageway coupled to the pressure chamber.
11. A medication delivery system, as set forth in claim 10, further
including a cap having a closed end and an open end and being
coupled to the valve housing at the open end.
12. A medication delivery system, as set forth in claim 10, wherein
the outlet passageways of the multiple site infusion apparatus
contain restrictive orifices.
13. A medication delivery system, as set forth in claim 1, further
comprising a valve system coupled to the pump outlet for providing
flow restriction and anti-siphoning characteristics.
14. A medication delivery system, as set forth in claim 13, the
valve system including a divider for dividing the flow of
medication into each leg and a check valve in each leg.
15. A mediciation delivery system, as set forth in claim 13,
wherein the valve system includes a divider for dividing the flow
of medication into each leg and a flow restrictor in each leg.
16. A method for delivering medication using a medication delivery
system, including the steps of: storing a supply of medication;
receiving a desired flow rate of medication; and, providing a flow
of medication from the supply of medication in the form of a series
of pulses, the flow being provided through an outlet and subdivided
into a plurality of legs, wherein the series of pulses are
determined to provide an outlet pressure at the pump outlet adapted
to reduce an effect of any differential pressure between the
legs.
17. A method, as set forth in claim 13, including the step of
determining a period of time between a start of each pulse, wherein
the period of time is determined such that each pulse begins before
a predetermined drop in fluid pressure level occurs.
18. A method, as set forth in claim 14, wherein the series of
pulses is subdivided into groups of pulses, a start of each pulse
within each group being separated by a first period of time and a
start of the first pulse in each group being separated by a second
period of time.
19. A method, as set forth in claim 14, wherein the second period
of time is determined as a function of the desired fluid flow.
Description
RELATED APPLICATIONS
[0001] This patent application claims priority to U.S. Provisional
Patent Application Serial No. 60/451,161 ("TWO SITE INFUSION
APPARATUS") filed Feb. 28, 2003 and is a continuation-in-part
application of U.S. patent application Ser. No. 10/083,266, filed
Feb. 23, 2002, which claims priority to and all advantages of U.S.
Provisional Patent Application No. 60/271,187 which was filed on
Feb. 23, 2001.
FIELD OF THE INVENTION
[0002] The present invention relates generally to the delivery of a
pulsatile fluid pulse, and more particularly to an apparatus for
controllably dividing a pulsatile fluid flow into two or more
pulsatile fluid flows.
BACKGROUND OF THE INVENTION
[0003] Medication delivery systems are known in the art. Medication
delivery systems are used to deliver pain control medication and
other medications intra-operatively, subcutaneously, and
percutaneously to a patient after a surgical, or some other
medical, procedure.
[0004] It is sometimes desirable to deliver a fluid using a
pulsatile fluid flow or series of pulses. For example, some
medication delivery systems which utilize a series of pulsatile
fluid pulses to deliver medication, are known in the art.
Medication delivery systems may be used to deliver pain control
medication and other medications intra-operatively or
post-operatively, subcutaneously, and percutaneously to a patient
after a surgical, or some other medical, procedure.
[0005] For example, U.S. Pat. No. 5,807,075 to Jacobsen et al.
discloses a conventional medication delivery system that includes a
base housing and a cassette. The base housing of the '075 patent
houses electronic components, such as an electric motor, a power
source, and an electronic controller, and the cassette of the '075
patent interacts with a supply of the medication to deliver the
medication to the patient.
[0006] A further example of a conventional medication delivery
system is disclosed in U.S. Pat. No. 4,650,469 to Berg et al. This
patent discloses a medication delivery system that includes a
control module and a reservoir module removably connected to the
control module. The control module includes a pump mechanism,
valves, a power source, electronic controls, and the like, and the
reservoir module includes a container that supplies the medication
to be delivered to the patient.
[0007] It is known to use an electric motor in such medication
delivery systems, where a predetermined number at revolutions or
cycles of the motor delivers a preset amount of medication. Such
systems are known as positive displacement systems. In such
systems, pressurization of the medication is a function of the
restrictions in the flow path and the time dependent flow of
medication through the system.
[0008] Generally, conventional medication delivery systems provide
a flow of medication through an output tube which then is delivered
to the patient, as required. However in some procedures, medication
is required at two locations with respect to the patient, for
example, breast augmentation or reconstruction. Another such
procedure where medication delivery is desirable at two sites is an
autologous graft procedure where it is desirable to deliver
medication at both the graft and the donor sites. If the medication
provided by the delivery system is pumped through a "Y" connection,
then there are several reasons that the medication may not be
delivered to each site or location in the desired proportion.
First, unequal pressure at the two infusion sites due to elevation
or intracompartmental pressure sets up a siphon where flow occurs
from one side to the other side in the period between pulses.
Furthermore, natural or unintended variations in flow restriction
between the two sides of the "Y" and/or the previously mentioned
unequal infusion site pressures may shift the proportion of the
flow split, as more flow will follow the path of decreased
resistance. This is undesirable.
[0009] In a mechanical system experiencing laminar flow of a
non-compressible fluid, a similar phenomenon occurs whereby the
pressure between two points is directly proportional to the mass
flow rate through the system and the flow restriction between the
two points.
[0010] This can be expressed as .DELTA.P={dot over (M)}R, where
[0011] .DELTA.P=Pressure Differential (psi)
[0012] M Mass Flow Rate (cc/sec)
[0013] R=Flow Restriction (psi/[cc/sec])
[0014] Similarly, 1 M . = P R
[0015] In other words, the instantaneous flow rate in a
single-lumen system is directly related to the instantaneous
pressure between two points separated by a known flow restriction,
and it is inversely proportional to the value of the restriction
between those two points.
[0016] In a scenario where more than one distal site is linked to
the fluid path, the overall flow rate to both sites as well as the
percent flow reaching each site is also related to pressure and
restriction. Though capacitance in the system may cause a phase
shift in the instantaneous flow rate from location to location, the
overall flow from the lumen upstream of the branching node will
equal the sum of the overall flow coming through each outlet lumen
(leg).
[0017] In this scenario, the instantaneous flow rate along each leg
will be directly related to the difference in pressure between the
branching node and the distal outlet of the leg, and it will be
inversely proportional to the flow restriction along that leg. The
mass flow rate through any given outlet lumen may be calculated as
follows: 2 M i . = P i R i = P 0 - P i R i
[0018] where
[0019] .DELTA.Pi=P0-Pi
[0020] P0=Pressure at branching node (psi gage)
[0021] Pi=Pressure at outlet of lumen i (psi gage)
[0022] Ri=Flow Restriction of outlet lumen i (psi/[cc/sec])
[0023] The total flow through all legs is then 3 M . total = i = 1
n M . i = i = 1 n P 0 - P i R i ,
[0024] and the percent flow to any given outlet lumen is 4 % F = (
100 ) M i . M . total .
[0025] If a pump with a pulsatile flow delivery system is connected
to a fluid delivery path, and it is desired to controllably divide
the flow between the multiple outlet sites, the flow restrictions
in each outlet lumen may be designed so as to facilitate the
desired flow distribution. With each pulse of fluid flow from the
pump, the pressure in the inlet lumen and the branching node will
rise--with a lower system capacitance before the node leading to a
more steep pressure rise. After the pump finishes introducing fluid
to the path, a pressure drop will be observed as fluid drains
through the outlet lumens, emptying the fluid stored by the
capacitance of the system. As stated before, the instantaneous flow
rate during this process is related to the pressure differential
and the flow restriction; as the pressure drops asymptotically to
an equilibrium level, so will the flow decrease proportionally.
[0026] If the pressure at all outlet sites is the same, then
.DELTA.P will be the same for each outlet lumen and the flow
distribution may be directly controlled by the flow restrictors
alone.
[0027] However, if the pressures of the outlets are not equal and
not constant, then additional measures are required to equally or
accurately distribute the flow as desired to all sites. This can be
accomplished by making the pressure at the node high enough that
the variation in pressures at each site do not contribute greatly
to percent variation in pressure differential. In other words, if
P.sub.1.noteq.P.sub.2 but P.sub.0>>P.sub.1 and
P.sub.0>>P.sub.2, then .DELTA.P.sub.1=.DELTA.P.sub.2. If
.DELTA.P1 and .DELTA.P2 are then similar, the restriction level of
each lumen may once again be relied upon to provide the control
necessary to balance the flow percentage to each lumen outlet.
[0028] However, in the case of a pulsatile pump, the time-dependent
pressure profile may not provide the necessary conditions to keep
P.sub.0>>P.sub.1 and P.sub.0>>P.sub.2. A substantial
portion of fluid flow occurs as the pressure profile drops during
the drain cycle mentioned above, and as the pressure drops, the
.DELTA.Pi of the various paths will deviate farther and farther
from each other, in relation to the difference in Pi at each outlet
location.
[0029] One solution would be to provide a check valve in each leg
after the "Y" connection. This solution presents several problems,
namely, there is a time delay added by the opening and closing of
the check valve and differences in manufacturing tolerances
contributing to the delay may also lead to uneven delivery of the
medication. Furthermore, most check valves restrict flow when open,
and unequal or uncontrollable variations in this restriction would
lead to unequal flow.
[0030] Another solution would be to provide a large fluid resistor
(small orifice) in each leg. Correctly sizing this orifice would
cause the pressure to rise substantially higher than the downstream
pressure differences. This pressure could be driven up over several
pulses. If the pressure remained higher than the highest downstream
pressure, no backflow due to siphoning could occur. Furthermore,
the difference in the pressure drop in the two downstream legs
could be controlled to remain relatively equal. This solution
presents several problems. First, if the pump has a user selectable
flow rate, the size of the glass orifice must be fixed to work with
the lowest possible flow rate. If a higher flow rate were then
selected, the level of restriction would cause an increase in
pressure beyond acceptable limits for safety or function the system
or its components, including features such as an occlusion
sensor.
[0031] The present invention is aimed at one or more of the
problems set forth above.
SUMMARY OF THE INVENTION AND ADVANTAGES
[0032] In one aspect of the present invention, a medication
delivery system is provided. The system includes a reservoir for
storing a supply of medication and a pump assembly coupled to the
reservoir. The pump assembly has a pump inlet and a pump outlet and
is controllable to provide a flow of medication in the form of a
series of pulses. The pump outlet is subdivided into a plurality of
legs. A controller is coupled to the pump assembly for controlling
the pump assembly and receives a desired flow of medication and
responsively controls the pump assembly to provide a series of
pulses of medication to provide the desired flow of medication. The
series of pulses are determined to provide an outlet pressure at
the pump outlet adapted to reduce an effect of any differential
pressure between the legs.
[0033] In another aspect of the present invention, a method for
delivering medication using a medication delivery system is
provided. The method includes the steps of storing a supply of
medication, receiving a desired flow of medication, and providing a
flow of medication from the supply of medication in the form of a
series of pulses. The flow is provided through an outlet and
subdivided into a plurality of legs. The series of pulses are
determined to provide an outlet pressure at the pump outlet adapted
to reduce an effect of any differential pressure between the
legs.
BRIEF DESCRIPTION OF THE DRAWINGS
[0034] Other advantages of the present invention will be readily
appreciated as the same becomes better understood by reference to
the following detailed description when considered in connection
with the accompanying drawings wherein:
[0035] FIG. 1A is a perspective view of an integrated medication
delivery system according to the subject invention with an infusion
tube set;
[0036] FIG. 1B is a perspective view of an underside of the system
illustrating a system mounting clip for securing the system to a
patient;
[0037] FIG. 2A is an exploded perspective view of the system
illustrating a medication reservoir, a base housing, reservoir
casings, a pump assembly, and a carrying strap of the system;
[0038] FIG. 2B is an exploded perspective view of the system
illustrating a removable overlay label, a patient label, and a top
housing of the base housing for assembly to the system;
[0039] FIG. 3 is an exploded perspective view of the system
illustrating a port, a plunger, the pump assembly including a motor
and first and second pinch levers, an actuator, and the base
housing including an integral storage cavity for the carrying
strap;
[0040] FIG. 4 is an exploded perspective view of the system
illustrating an underside of the top housing, at least one control
button, an electronic controller and display, and a detection film
having a cantilever portion;
[0041] FIG. 5 is an exploded perspective view of the pump
assembly;
[0042] FIG. 6A is a partially cross-sectional side view of a cam
shaft, the pump assembly, and the first and second pinch levers
illustrating the pinch levers in a closed position to pinch
medication inlet and outlet tubes;
[0043] FIG. 6B is a partially cross-sectional side view of the
system, as disclosed in FIG. 6A, illustrating the first pinch lever
in an open position and the second pinch lever in a closed position
to draw medication into the pump assembly;
[0044] FIG. 6C is a partially cross-sectional side view of the
system, as disclosed in FIG. 6A, illustrating the first pinch lever
in a closed position and the second pinch lever in an open position
to displace medication from the pump assembly;
[0045] FIG. 6D is a partially cross-sectional side view of the
system, as disclosed in FIG. 6A, in combination with the plunger
and the actuator, with the actuator retaining the pinch levers in
the open position;
[0046] FIG. 7 is a partially cross-sectional side view of the pump
assembly;
[0047] FIG. 8 is an exploded perspective view of the port and the
plunger;
[0048] FIG. 9 is an enlarged partially cross-sectional top view of
the plunger disposed in the port illustrating a first, second, and
third fluid connector;
[0049] FIG. 10 is a partially cross-sectional side view taken along
line 10-10 in FIG. 9 illustrating a seal disposed about the plunger
being depressed by leak ribs extending from the port;
[0050] FIG. 11A is a partially cross-sectional top view of the
system with the plunger in an off-position;
[0051] FIG. 11B is a partially cross-sectional view of the port and
the plunger disposed in the port in the off-position from FIG.
11A;
[0052] FIG. 12A is a partially cross-sectional top view of the
system with the plunger in a fill-position such that the system can
be sterilized and filled with medication;
[0053] FIG. 12B is a partially cross-sectional view of the port and
the plunger disposed in the port in the fill-position from FIG. 12A
additionally illustrating a syringe for moving the plunger into the
fill-position and a fluid cap for sterilization;
[0054] FIG. 13A is a partially cross-sectional top view of the
system with the plunger in a fluid delivery-position such that the
medication can be delivered to the patient;
[0055] FIG. 13B is a partially cross-sectional view of the port and
the plunger disposed in the port in the fluid delivery-position
from FIG. 13A additionally illustrating a connector from the
infusion tubing set;
[0056] FIG. 14A is an enlarged perspective view of the
actuator;
[0057] FIG. 14B is a perspective view of an alternative embodiment
for the actuator including a control contact disposed at a distal
end of an actuation arm;
[0058] FIG. 15A is a partially cross-sectional side view of a
blockage detection system according to the subject invention when
the medication outlet tube is in a normal condition;
[0059] FIG. 15B is a partially cross-sectional side view of the
blockage detection system of FIG. 15A when the medication outlet
tube is in an expanded condition due to a blockage;
[0060] FIG. 16A is a partially cross-sectional side view of an
empty detection system according to the subject invention when the
medication inlet tube is in a normal condition;
[0061] FIG. 16B is a partially cross-sectional side view of the
empty detection system of FIG. 16A when the medication inlet tube
is in a collapsed condition due to a depletion in the supply of the
medication;
[0062] FIG. 17 is a perspective view of a support platform with the
medication inlet and outlet tubes which also illustrates
alternative embodiments for the blockage detection system and the
empty detection system where a coating is applied to the medication
inlet and outlet tubes;
[0063] FIG. 18A is a top perspective view of the system engaged
with a testing instrument for confirming proper operation of the
system after assembly and prior to use;
[0064] FIG. 18B is a bottom perspective view of the system engaged
with a second testing instrument for confirming proper operation of
the system after assembly and prior to use;
[0065] FIG. 19 is a perspective view of the patient using the
carrying strap as a shoulder strap to carry the system;
[0066] FIG. 20 is an enlarged top perspective view of the integral
storage cavity defined within the base housing of the system;
[0067] FIG. 21 is a perspective view of a surgeon or patient
removing the removable overlay label to reveal the patient
label;
[0068] FIG. 22 is a plan view of one embodiment of the removable
overlay label having a one version of a first set of explanatory
indicia;
[0069] FIG. 23 is a plan view of a further embodiment of the
removable overlay label having another version of a first set of
explanatory indicia;
[0070] FIG. 24 is a plan view of the patient label having a second
set of explanatory indicia;
[0071] FIG. 25 is a block diagram schematically illustrating a
control system for the integrated medication delivery system of the
subject invention;
[0072] FIG. 26 is an electrical diagram illustrating portions of a
watchdog circuit of the control system; and
[0073] FIG. 27 is an electrical diagram illustrating further
portions of the watchdog circuit of the control system.
[0074] FIG. 28 is graphical illustration of a tube set divided into
a plurality of legs, according to an embodiment of the present
invention;
[0075] FIG. 29A is a graph illustrating a series of pulses divided
into first and second groups, according to an embodiment of the
present invention;
[0076] FIG. 29B is a graph of an exemplary pressure profile during
a group of pulses in which the system pressure is allowed to drop
to the outlet pressure after the group;
[0077] FIG. 29C is a graph of an exemplary pressure profile during
2 groups of pulses in which a mechanism is in place to hold system
pressure at or above a predetermined level after the first
group;
[0078] FIG. 29D is a diagrammatical illustration of a tube set
having a Y-divider, at least one check valve and a flow restrictor
in each leg, according to an embodiment of the present
invention;
[0079] FIG. 30 is a first isometric view of a two site infusion
apparatus, according to an embodiment of the present invention;
[0080] FIG. 31 is second isometric view of the two site infusion
apparatus of FIG. 1;
[0081] FIG. 32 is a top down view of the two site infusion
apparatus of FIG. 1;
[0082] FIG. 33 is a side view of the two site infusion apparatus of
FIG. 1;
[0083] FIG. 34 is a bottom view of the two site infusion apparatus
of FIG. 1;
[0084] FIG. 35 is a first cut-away view of the two site infusion
apparatus of FIG. 1; and,
[0085] FIG. 36 is a second cut-away view of the two site infusion
apparatus of FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
[0086] Referring to the Figures, wherein like numerals indicate
like or corresponding parts throughout the several views, an
integrated medication delivery system 10 is generally disclosed at
10. The integrated medication delivery system 10, hereinafter
described as the system 10, delivers medication to a patient 12
(refer to FIG. 19). More specifically, the system 10 is primarily
used throughout the medical profession to deliver pain control
medication and other medications to the patient 12 after a
surgical, or some other medical, procedure. As disclosed in FIG.
1B, the system 10 is used in combination with an infusion tube set
14 to deliver the medication to the patient 12. The infusion tube
set 14 is described below.
[0087] The system 10 of the subject invention is also suitable for
complete sterilization by a sterilization fluid including, but not
limited to, ethylene oxide (EtO) gas. Although not ideal, certain
liquids may even be used to sterilize the system 10. For
descriptive purposes only, the terminology of "medication" and of
"sterilization" fluid may also be described throughout simply as a
fluid.
[0088] Referring primarily to FIGS. 2A-3, the system 10 includes a
base housing 16. The base housing 16 is further defined as a bottom
housing 18, a middle housing 20 mounted to the bottom housing 18
and a top housing 22, i.e., a cover. The housings 18, 20, 22 are
preferably mounted together via screws 23. The system 10 also
includes a medication reservoir 24 disposed about the base housing
16. More specifically, the reservoir 24 is disposed about the
middle housing 20. The reservoir 24 stores the supply of medication
that is to be delivered to the patient 12. Preferably, the
reservoir 24 is formed of a flexible, yet durable plastic material.
The system 10 further includes a reservoir casing 26 disposed
between the bottom and top housings 18, 22. The reservoir casing 26
at least partially surrounds the reservoir 24 to protect the
medication that is to be delivered to the patient 12. The preferred
embodiment of the subject invention includes two reservoir casings
26 that surround the reservoir 24 to protect the medication. Of
course, it is to be understood that the reservoir casing 26 may be
a unitary component and still adequately surround the reservoir 24
to protect the medication. The reservoir casing 26 is particularly
useful when the patient 12 is carrying the system 10. Carrying of
the system 10 is described below.
[0089] Referring primarily to FIGS. 2A, 3, and 5-6D, a pump
assembly 28 is supported by the base housing 16. Specifically, the
pump assembly 28 is mounted to the bottom housing 18. As understood
by those skilled in the art, the pump assembly 28 is responsible
for delivering the medication to the patient 12. As described
below, the pump assembly 28 also serves to prevent inadvertent
delivery of the medication to the patient 12.
[0090] As disclosed best in FIG. 5, the pump assembly 28 includes a
pump housing 30 having a pump inlet 32 and a pump outlet 34. The
pump housing 30 also has at least one detent 36. The at least one
detent 36 is described below. The pump inlet 32 and the pump outlet
34 alternate between an open and a closed state to deliver the
medication to the patient 12. Referring now to FIGS. 3, and 6A-6D,
a first pinch lever 38, also referred to as a pinch valve, is
disposed at the pump inlet 32 and a second pinch lever 40 or valve
is disposed at the pump outlet 34. The first pinch lever 38
functions to alternate the pump inlet 32 between the open and the
closed state, and the second pinch lever 40 functions to alternate
the pump outlet 34 between the open and the closed state.
[0091] As FIGS. 6B and 6C disclose, the first pinch lever 38 is
moveable between an open position (FIG. 6B) and a closed position
(FIG. 6C) to control a flow of the medication into the pump housing
30 through the pump inlet 32, and the second pinch lever 40 is
moveable between an open position (FIG. 6C) and a closed position
(FIG. 6B) to control a flow of the medication from the pump housing
30 through the pump outlet 34. The pump assembly 28 further
includes a motor 42 that is operatively engaged to the first and
second pinch levers 38, 40 for moving these levers 38, 40 into the
open position such that the medication can be delivered to the
patient 12. The motor 42 includes a driving output shaft, not shown
in the Figures, for driving the pump assembly 28. A power source 43
is integrated into the system 10 to provide power to the system 10,
including the motor 42. Preferably, the power source includes
batteries 45 and battery contacts 47.
[0092] As shown in FIG. 6A, the first pinch lever 38 is
normally-biased to maintain the pump inlet 32 in the closed state
and the second pinch lever 40 is normally-biased to maintain the
pump outlet 34 in the closed state. To accomplish this, at least
one biasing device 44 is included in the pump assembly 28.
Preferably, the at least one biasing device 44 is a compression
spring as shown, but not numbered, throughout the Figures. However,
it is to be understood that the at least one biasing device 44 may
be any device that is suitable for normally-biasing at least one,
if not both, of the first and second pinch levers 38, 40 into the
closed position. The at least one biasing 44 device engages at
least one of the first and second pinch levers 38, 40 and works in
conjunction with the motor 42 to normally bias at least one of the
first and second pinch levers 38, 40 into the closed position. As
such, if the motor 42 fails during delivery of the medication, then
the first and second pinch levers 38, 40 are biased into and
thereafter maintained in the closed position to prevent the
inadvertent delivery of the medication to the patient 12. The motor
42 is able to move the first and second pinch levers 38, 40 into
the open position despite the bias of the at least one biasing
device 44.
[0093] In the preferred embodiment of the subject invention, the at
least one biasing device 44 comprises a first 46 and a second 48
biasing device. The first biasing device 46, preferably a
compression spring, engages the first pinch lever 38, and the
second biasing device 48, also preferably a compression spring,
engages the second pinch lever 40. As disclosed in FIG. 6A, the
first and second biasing devices 46, 48 maintain the first and
second pinch levers 38, 40 in the closed position during failure of
the motor 42 thereby preventing the inadvertent delivery of the
medication to the patient 12. More specifically, the closed first
pinch lever 38 prevents the medication from being drawn into the
pump assembly 28 through the pump inlet 32, and the closed second
pinch lever 40 prevents the medication from being displaced from
the pump assembly 28 through the pump outlet 34.
[0094] Referring primarily to FIGS. 5-6D, to effectively operate
the system 10 and move the first and second pinch levers 38, 40 for
delivery of the medication to the patient 12, the pump assembly 28
of the subject invention further includes a cam shaft 50 supported
on the pump housing 30. The cam shaft 50 is geared to the motor 42,
via a number of gears 52, to operatively engage the motor 42 to the
first and second pinch levers 38, 40. The cam shaft 50 is described
in greater detail below.
[0095] As disclosed best in FIGS. 5 and 7, the pump assembly 28
also includes a piston 54 disposed in the pump housing 30. The
motor 42 moves the piston 54 within the pump housing 30 to draw the
medication into the pump housing 30 when the first pinch lever 38
is in the open position and the second pinch lever 40 is in the
closed position (see FIG. 6B). The motor 42 also moves the piston
54 within the pump housing 30 to displace the medication from the
pump housing 30 when the first pinch lever 38 is in the closed
position and the second pinch lever 40 is in the open position (see
FIG. 6C). The piston 54 includes an actuation end 56 and a pumping
end 58. A diaphragm seal 60 is disposed at the pumping end 58 of
the piston 54. The diaphragm seal 60 is secured at the pumping end
58 of the piston 54 by a piston cap 62. The piston 54 also includes
at least one slot 62 at the actuation end 56. The at least one
detent 36 of the pump housing 30, originally introduced above,
engages the at least one slot 62 at the actuation end 56 of the
piston 54 to prevent unwanted rotation of the piston 54 as the
piston 54 is moved within the pump housing 30 by the motor 42 and
the cam shaft 50.
[0096] The cam shaft 50 supports first and second outside cams 64,
66 and an inside cam 68. The inside cam 68 of the cam shaft 50 is
disposed between the first and second outside cams 64, 66. The
first outside cam 64 engages the first pinch lever 38 to move the
first pinch lever 38 between the open and closed position, and the
second outside cam 66 engages the second pinch lever 40 to move the
second pinch lever 40 between the open and closed positions. The
inside cam 68 engages the actuation end 56 of the piston 54 to move
the piston 54 within the pump housing 30.
[0097] Referring to FIG. 5, the first and second outside cams 64,
66 include a plurality of slits 70 along an outer circumference 72
of the cams 64, 66. These slits 70 are used during assembly and
testing of the system 10 to confirm dimensional tuning of the cams
64, 66. Also, at least one of the first and second outside cams 64,
66, preferably the first outside cam 64, includes an assembly slot
74 defined within the outer circumference 72 of the cams 64, 66.
This assembly slot 74 facilitates assembly of the pump assembly 28.
In particular, this assembly slot 74 facilitates mounting of the
cam shaft 50, including the cams 64, 66, after the first and second
pinch levers 38, 40 have already been incorporated into the system
10.
[0098] Each of the first and second pinch levers 38, 40 comprise a
cam follower 76 and lever guides 78. The lever guides 78 are
described below. The cam followers 76 of the pinch levers 38, 40
are engaged by the cam shaft 50 for alternating movement of the
first and second pinch levers 38, 40 between the open and closed
positions such that the medication can be delivered to the patient
12. More specifically, the cam follower 76 of the first pinch lever
38 is engaged by the first outside cam 64 for alternating movement
of the first pinch lever 38 between the open and closed positions,
and the cam follower 76 of the second pinch lever 40 is engaged by
the second outside cam 66 for alternating movement of the second
pinch lever 40 between the open and closed positions. Even more
specifically, each of the first and second outside cams 64, 66
include internal cam surfaces 80. As disclosed in FIGS. 6A-6D, the
cam follower 76 of the first pinch lever 38 rides within the
internal cam surface 80 of the first outside cam 64 for alternating
movement of the first pinch lever 38, and the cam follower 76 of
the second pinch lever 40 rides within the internal cam surface 80
of the second outside cam 66 for alternating movement of the second
pinch lever 40.
[0099] Referring primarily to FIGS. 3, and 8-10, the system 10
further includes a port assembly 82 that enables various fluids,
such as the medication or the sterilization fluid, to flow into,
from, and within the system 10. The port assembly 82, hereinafter
described as the port 82, extends from the base housing 16. More
specifically, the port 82 extends from the middle housing 20. The
port 82 is in fluid communication with the reservoir 24 and the
pump assembly 28. During sterilization, the port 82 provides access
for the sterilization fluid to flow into the reservoir 24 and the
pump assembly 28. During filling, the port 82 provides access for
the medication to flow into the reservoir 24 and the pump assembly
28. During delivery of the medication to the patient 12, the port
82 provides access for the medication to be delivered to the
patient 12.
[0100] Referring particularly to FIGS. 9, and 11A-13B, the port 82
includes an elongated housing 84. The elongated housing 84 includes
a proximate end 86, a distal end 88, and an interior wall 90
defining a fluid chamber 92 between the proximate and distal ends
86, 88. It is the proximate end 86 of the elongated housing 84 that
extends from the system 10 to provide access for the fluid to flow
both into and from the system 10. The port 82 further includes a
first fluid connector 94, a second fluid connector 96, and a third
fluid connector 98. The first fluid connector 94, alternatively
referred to as an outlet of the port 82, extends from the elongated
housing 84 to allow the fluid to flow from the fluid chamber 92
into the pump assembly 28. The second fluid connector 96,
alternatively referred to as an inlet to the port 82, extends from
the elongated housing 84 to allow the fluid to flow from the pump
assembly 28 into the fluid chamber 92. The third fluid connector
98, alternatively referred to as an access to the reservoir 24,
extends from the elongated housing 84 to allow the fluid to flow
between the fluid chamber 92 and the reservoir 24. In the preferred
embodiment of the subject invention, there are two third fluid
connectors 98, one third fluid connector 98 extending from opposite
sides of the elongated housing 84.
[0101] Referring primarily to FIGS. 3, 6D, 8-10, and 11A-13B, the
port 82 further includes a plunger 100. The plunger 100 is disposed
in the fluid chamber 92 of the port 82 and is moveable between an
off-position (FIGS. 11A-11B), a fill-position (FIGS. 12A-12B), and
a fluid delivery-position (FIGS. 13A-13B). As disclosed in FIGS.
11A-11B, in the off-position, the first, second, and third fluid
connectors 94, 96, 98 are isolated from the proximate end 86 of the
elongated housing 84 by the plunger 100. As a result, the flow of
fluid through the port 82 is prevented. As disclosed in FIGS.
12A-12B, in the fill-position, the first and third fluid connectors
94, 98 are in fluid communication with the proximate end 86 of the
elongated housing 84. As a result, a fluid flow path, shown but not
numbered in FIGS. 12A-12B, is provided between the proximate end 86
of the elongated housing 84, the medication reservoir 24, and the
pump assembly 28 such that the fluid can be filled through the
proximate end 86 of the housing and into the medication reservoir
24 and the pump assembly 28. This fluid flow path is defined
between the port 82, the reservoir 24, and the pump assembly 28
such that the flow of sterilization fluid through the fluid flow
path is continuous during sterilization of the system 10. The
fill-position of the plunger 100 is utilized when the system 10 is
being sterilized with the sterilization fluid and also when the
system 10 is being filled with medication. As disclosed in FIGS.
13A-13B, in the fluid delivery position, the first, second, and
third fluid connectors 94, 96, 98 are in fluid communication with
the proximate end 86 of the elongated housing 84 and with each
other for supplying the pump assembly 28 and for delivering the
fluid to the patient 12.
[0102] Referring primarily to FIGS. 3, 6D, 11A, 12A, 13A, and
14A-14B, the system 10 further includes an actuator 102 disposed in
the base housing 16. The actuator 102 is moveable between a
disengaged position and an engaged position. The disengaged
position of the actuator 102 is described below. As disclosed in
FIG. 6D, in the engaged position, the actuator 102 operatively
engages the pump inlet 32 and the pump outlet 34 to retain, i.e.,
lock, both the pump inlet 32 and the pump outlet 34 in the open
state during sterilization. With the pump inlet 32 and the pump
outlet 34 in the open state, the sterilization fluid can penetrate
throughout the entire system 10 to completely sterilize the system
10. That is, the sterilization fluid can penetrate into the
reservoir 24, the pump inlet 32, the pump housing 30, and the pump
outlet 34 to completely sterilize the system 10.
[0103] More specifically, the actuator 102 interacts with the first
and second pinch levers 38, 40 to retain both the pump inlet 32 and
the pump outlet 34 in the open state during sterilization. In the
engaged position, the actuator 102 moves the first pinch lever 38
away from the pump inlet 32 into the open position to retain the
pump inlet 32 in the open state, and the actuator 102 moves the
second pinch lever 40 away from the pump outlet 34 into the open
position to retain the pump outlet 34 in the open state. The
actuator 102 retains both the first and second pinch levers 38, 40
in the open position for sterilization despite the bias of the at
least one biasing device 44.
[0104] On the other hand, when the actuator 102 is in the
disengaged position, as indicated by the absence of the actuator
102 from FIGS. 6B-6C, the actuator 102 is operatively disengaged
from the pump inlet 32 and the pump outlet 34. The actuator 102 is
in the disengaged position when it is necessary to deliver the
medication to the patient 12 such that the pump inlet 32 and the
pump outlet 34 can alternate between the open and closed states to
deliver the medication the patient 12. Disengagement of the
actuator 102 permits the pump inlet 32 and the pump outlet 34 to
alternate between the open and closed states.
[0105] Referring particularly to FIGS. 14A-14B, the actuator 102 is
disclosed in greater detail. The actuator 102 includes a base
portion 104 and at least one engagement arm 106 extending from the
base portion 104. The at least one engagement arm 106 of the
actuator 102 operatively engages the pump assembly 28 to retain the
pump inlet 32 and the pump outlet 34 in the open state during
sterilization. In the preferred embodiment of the subject
invention, the actuator 102 more specifically includes first and
second engagement arms 108, 110, respectively, extending from the
base portion 104. In the preferred embodiment, the actuator 102
also includes an actuation arm 112. The actuation arm 112 extends
from the base portion 104 between the first and second engagement
arms 108, 110. As shown in the Figures, the actuation arm 112
extends upwardly from the base portion 104 between the first and
second engagement arms 108, 110.
[0106] During sterilization, the first engagement arm 108 of the
actuator 102 engages the first pinch lever 38 to move the first
pinch lever 38 away from the pump inlet 32 to retain the pump inlet
32 in the open state. Similarly, during sterilization, the second
engagement arm 110 of the actuator 102 engages the second pinch
lever 40 to move the second pinch lever 40 away from the pump
outlet 34 to retain the pump outlet 34 in the open state.
[0107] After sterilization it is desirable to move the actuator 102
into the disengaged position such that the pump assembly 28 can
operate and the medication can be delivered to the patient 12. As
indicated by the arrow (A) in FIG. 6D, the plunger 100 moves to
displace the actuator 102 from the engaged position thereby moving
the actuator 102 into the disengaged position. To displace the
actuator 102, the plunger 100 engages the actuation arm 112. The
plunger 100 displaces the actuator 102 from the operative
engagement with the pump assembly 28 after sterilization such that
the pump inlet 32 and the pump outlet 34 can alternate between the
open and the closed state to deliver the medication to the patient
12. More specifically, the plunger 100 displaces the actuator 102
from the engagement with the first and second pinch levers 38, 40
after sterilization such that medication can be delivered to the
patient 12. As such, the motor 42, which is operatively engaged to
the first and second pinch levers 38, 40, can move these levers 38,
40 for drawing the medication into the pump housing 30 through the
pump inlet 32 and for displacing the medication from the pump
housing 30 through the pump outlet 34.
[0108] Referring now to FIG. 14B, a control contact 114, preferably
a spring-like control contact 114, may be disposed at a distal end
116 of the actuation arm 112 away from the base portion 104 to
indicate to the system 10 whether the actuator 102 is in the
engaged or the disengaged position. The control contact 114
interacts with the actuation arm 112 of the actuator 102 upon the
movement of the actuator 102 between the engaged or the disengaged
position. If the control contact 114 is included, it is preferred
that when the actuator 102 is disengaged from the first and second
pinch levers 38, 40, i.e., when the actuator 102 is in the
disengaged position, it contacts the control contact 114 to active
an electronic controller 118. The electronic controller 118 is
activated to permit the pump assembly 28 to operate for delivering
the medication to the patient 12. As indicated above, it is
preferred that the actuation arm 112 of the actuator 102 is in
contact with the control contact 114 when the actuator 102 is in
the disengaged position. Of course, it is to be understood that the
opposite could be true. That is, the system 10 can be designed such
that the actuation arm 112 of the actuator 102 is in contact with
the control contact 114 when the actuator 102 is in the engaged
position.
[0109] The system 10 further includes a medication inlet tube 120
and a medication outlet tube 122. The medication inlet tube 120 is
connected between the port 82 and the pump inlet 32 to provide
access for the sterilization fluid to flow from the port 82 into
the pump assembly 28, specifically into the pump inlet 32. The
medication outlet tube 122 is connected between the pump outlet 34
and the port 82 to provide access for the sterilization fluid to
flow from the pump assembly 28, specifically from the pump outlet
34, into the port 82. The medication inlet tube 120 and the first
pinch lever 38 together establish the pump inlet 32, and the
medication outlet tube 122 and the second pinch lever 40 together
establish the pump outlet 34.
[0110] When the at least one biasing device 44 engages the first
pinch lever 38 to normally-bias the first pinch lever 38 into the
closed position, the medication inlet tube 120 is pinched. As such,
the pump inlet 32 is maintained in the closed state. Similarly,
when the at least one biasing device 44 engages the second pinch
lever 40 to normally-bias the second pinch lever 40 into the closed
position, the medication outlet tube 122 is pinched. As such, the
pump outlet 34 is maintained in the closed state. However, as
disclosed in FIG. 6D, when the actuator 102 is in the engaged
position during sterilization, the actuator 42 overcomes the bias
of the at least one biasing device 44 to move the first pinch lever
38 away from the medication inlet tube 120 such that the pump inlet
32 remains in the open state, and the actuator 102 overcomes the
bias of the at least one biasing device 44 to move the second pinch
lever 40 away from the medication outlet tube 122 such that the
pump outlet 34 remains in the open state.
[0111] Referring particularly to FIGS. 3, and 8-10, the port 82 and
the plunger 100 are described in greater detail. The plunger 100
includes a length L, a circumference C, and a plurality of seats
124 disposed along the length L and about the circumference C of
the plunger 100. The seats 124 extend outwardly from the
circumference C of the plunger 100 to the interior wall 90 of the
elongated housing 84 of the port 82 to segregate the fluid chamber
92 of the elongated housing 84. A fluid passage, not numbered, is
defined between each of the seats 124 and the interior wall 90 of
the housing. These fluid passages control the flow of fluid within
the port 82. Although the seats 124 may suitably segregate the
fluid chamber 92, it is preferred that seals 126 are disposed about
each of the seats 126 to assist with sealing the fluid passages
from one another. In the most preferred embodiment, which is shown
in the Figures, these seals are O-rings. At least one leak rib 128
extends at least partially along the interior wall 90 of the
elongated housing 84. The at least one leak rib 128 selectively
causes at least one of the seals 126 to leak when the plunger 100
is in the fill-position. As disclosed in the Figures, preferably
there are two leak ribs 128 that extend along the interior wall 90
of the elongated housing 84.
[0112] As shown in FIGS. 11A-13B, the plunger 100 is at least
partially hollow. As such, the plunger 100 defines an internal
fluid bore 130 that extends within the plunger 100 between the
seats 124. The plunger 100 further includes an access end 132 and a
plunger actuation end 134. A plunger biasing device 136, preferably
a compression spring, is disposed about the plunger actuation end
134 of the plunger 100 to bias the plunger 100 into the
off-position. The internal fluid bore 130 extends from the access
end 132, where the fluid flows into and from the internal fluid
bore 130, toward the plunger actuation end 134. The internal fluid
bore 130 includes a fluid duct 138 in fluid communication with one
of the fluid passages such that the flow can flow into and from the
internal fluid bore 130.
[0113] In the most preferred embodiment of the subject invention,
the plurality of seats 124 are further defined as a first, second,
third, and fourth seat 140, 142, 144, 146, respectively. The first
seat 140 is disposed toward the access end 132 of the plunger 100,
the fourth seat 146 is disposed toward the plunger actuation end
134 of the plunger 100, and the second and third seats 142, 144 are
disposed successively between the first and fourth seats 140, 146.
In this embodiment, the fluid passages are further defined as a
first, second, and third fluid passage 148, 150, 152, respectively.
The first fluid passage 148 is defined between the first and second
seats 140, 142 and the interior wall 90, the second fluid passage
150 is defined between the second and third seats 142, 144 and the
interior wall 90, and the third fluid passage 152 is defined
between the third and fourth seats 144, 146 and the interior wall
90.
[0114] A first seal 154 is disposed about the first seat 140 for
sealing the first fluid passage 148 from the access end 132 of the
plunger 100, a second seal 156 is disposed about the second seat
142 for sealing the first and second fluid passages 148, 150 from
one another, a third seal 158 is disposed about the third seat 144
for sealing the second and third fluid passages 150, 152 from one
another, and a fourth seal 160 is disposed about the fourth seat
146 for sealing the third fluid passage 152 from the plunger
actuation end 134 of the plunger 100. In this embodiment, the at
least one leak rib 128 extends along the interior wall 90 of the
elongated housing 84 from the proximate end 86 toward the distal
end 88 just beyond the first seal 154 such that only the first seal
154 selectively leaks when the plunger 100 is in the
fill-position.
[0115] In this most preferred embodiment, the internal fluid bore
130 extends within the plunger 100 from the access end 132 to the
third seat 144. As such, the fluid duct 138 is in fluid
communication with the second fluid passage 150 defined between the
second and third seats 142, 144 and the interior wall 90 such that
the fluid can flow into and from the internal fluid bore 130 at the
second fluid passage 150.
[0116] The off-, fill-, and fluid delivery-positions of the plunger
100 are now described in the context of this most preferred
embodiment having four seats 140, 142, 144, 146, three fluid
passages 148, 150, 152, and four seals 154, 156, 158, 160.
Referring to FIGS. 11A-11B, when the plunger 100 is in the
off-position, the first, second, and third fluid connectors 94, 96,
98 are isolated from the proximate end 86 of the elongated housing
84 and from the access end 132 of the plunger 100 by the first,
second, and third seats 140, 142, 144. In this off-position, the
first and third fluid connectors 94, 98 are aligned with the third
fluid passage 152.
[0117] Referring to FIGS. 12A-12B, when the plunger 100 is in the
fill-position, the first and third fluid connectors 94, 98 are in
fluid communication with the proximate end 86 of the elongated
housing 84 and with the access end 132 of the plunger 100 through
the second fluid passage 150 and the fluid duct 138 of the internal
fluid bore 130. In this fill-position, the first and third fluid
connectors 94, 98 are aligned with the second fluid passage 150. As
such, the fluid can be filled through the access end 132 of the
plunger 100, through the internal fluid bore 130 and the fluid duct
138, and into the reservoir 24 and the pump assembly 28. In the
fill-position, the second fluid connector 96 is isolated from the
proximate end 86 of the elongated housing 84, from the access end
132 of the plunger 100, and from the first and third fluid
connectors 94, 98 by the third and fourth seats 144, 146.
[0118] Referring to FIGS. 13A-13B, when the plunger 100 is in the
fluid delivery-position, the second fluid connector 96 is in fluid
communication with the proximate end 86 of the housing and with the
access end 132 of the plunger 100 through said second fluid passage
150 and the fluid duct 138 of the internal fluid bore 130. In the
fluid delivery-position, the medication is delivered from the pump
assembly 28 to the patient 12. In the fluid delivery-position, the
first and third fluid connectors 94, 98 are isolated from the
proximate end 86 of the housing and from the access end 132 of the
plunger 100 by the first and second seats 140, 142. However, the
first and third fluid connectors 94, 98 are in fluid communication
with the reservoir 24 through the first fluid passage 148 to supply
the pump assembly 28 with the fluid, i.e., with the medication.
That is, in the fluid delivery-position, the first and third fluid
connectors 94, 98 are aligned with the first fluid passage 148.
[0119] A fluid filling device, shown generally in FIG. 12B at 162,
engages the proximate end 86 of the housing to automatically move
the plunger 100 into the fill-position for filling the reservoir 24
and the pump assembly 28. If the system 10 is being sterilized,
then the fluid filling device 162 is preferably a fluid, or
sterilization, cap 164 (shown detached from the system 10 in FIG.
12B) that moves the plunger 100 into the fill-position to enable a
sterilization fluid to penetrate into the reservoir 24 and the pump
assembly 28. The fluid cap 164, by design, automatically moves the
plunger 100 into the fill-position. Therefore, when the system 10
is introduced into a chamber filled with the sterilization fluid,
preferably EtO gas, then the sterilization fluid flows, or seeps,
through the fluid cap 164, through the proximate end 86 of the
elongated housing 84 and the access end 132 of the plunger 100,
through the internal fluid bore 130 and the fluid duct 138, into
the second fluid passage 150, through the third fluid connector 98
into the reservoir 24, and through the first fluid connector 94
into the pump assembly 28.
[0120] If the system 10 is being filled with medication, then the
fluid filling device 162 is preferably a syringe 166 that moves the
plunger 100 into the fill-position for filling the reservoir 24 and
the pump assembly 28. The syringe 166 (shown attached to the system
10 in FIG. 12B) engages the access end 132 of the plunger 100 and,
by design, automatically moves the plunger 100 into the
fill-position for filling the reservoir 24 and the pump assembly 28
through the internal fluid bore 130. Therefore, when the system 10
is being filled, the syringe 166 interacts with the proximate end
86 of the elongated housing 84 and the access end 132 of the
plunger 100 and, as the syringe plunger is depressed, the
medication flows through the internal fluid bore 130 and the fluid
duct 138, into the second fluid passage 150, through the third
fluid connector 98 into the reservoir 24, and through the first
fluid connector 94 into the pump assembly 28.
[0121] To deliver the medication to the patient 12, the system 10
is utilized in combination with the infusion tube set 14. Referring
back to FIG. 1A, the infusion tube set 14 includes a fluid end 168
and a patient end 170. The fluid end 168 of the tube set 14,
through a delivery connector 172, engages the proximate end 86 of
the elongated housing 84 and the access end 132 of the plunger 100
to automatically move the plunger 100 into the fluid
delivery-position for delivering the medication to the patient 12.
Therefore, as shown in FIGS. 13A-13B, when the pump assembly 28 is
operating, the medication is drawn from the reservoir 24 through
the third fluid connector 98 into the port 82 at the first fluid
passage 148, and through the first fluid connector 94 into the pump
inlet 32. The medication is then displaced out of the pump assembly
28 through the pump outlet 34, through the second fluid connector
96 into the port 82 at the second fluid passage 150, through the
fluid duct 138 and the internal fluid bore 130 of the plunger 100,
and out the access end 132 of the plunger 100 at the fluid end 168
of the infusion tube set 14. From there, the medication flows
through the infusion tube set 14, out the patient end 170, and to
the patient 12.
[0122] Referring back to FIG. 4, the system 10 further includes the
electronic controller 118. The electronic controller 118 controls
an amount of the medication that is to be delivered to the patient
12. The electronic controller 118 is mounted to the base housing
16, specifically to the top housing 22 of the base housing 16.
Furthermore, the electronic controller 118 remains mounted to the
base housing 16 during sterilization such that the entire system
10, including all mechanical components, the reservoir 24, and the
electronic controller 118, is simultaneously sterilized. An
electronic display 174 and at least one control button 176 are
mounted to the base housing 16. The electronic display 174 and the
control button 176 interact with the electronic controller 118 to
control the amount of the medication to be delivered to the patient
12. As with the electronic controller 118, the electronic display
174 and the control button 176 also remain mounted to the base
housing 16 during sterilization.
[0123] The subject invention also provides a blockage detection
system which is generally disclosed at 178 in FIGS. 15A-15B. The
blockage detection system 178 detects a blockage in the flow of the
medication to the patient 12. The blockage detection system 178
comprises the base housing 16, the reservoir 24, the port 82, the
pump assembly 28, the medication outlet tube 122, and the
electronic controller 118. The blockage detection system 178 also
includes a detection film 180 which is described below.
[0124] In the blockage detection system 178, the electronic
controller 118 is mounted to the base housing 16 adjacent the
outlet tube 122. The outlet tube 122 is mounted to the base housing
16 and, as described above, is connected between the pump assembly
28 and the port 82 to provide access for the medication to flow
from the pump assembly 28 into the port 82 and to the patient 12.
The outlet tube 122 has a diameter that is contractible and
expandable between a normal condition (see FIG. 15A) and an
expanded condition (see FIG. 15B). The diameter of the outlet tube
122 contracts and expands in response to variations in pressure
that result from the flow of the medication from the reservoir 24
through the pump assembly 28 into the port 82 and to the patient
12.
[0125] As disclosed in the Figures, the outlet tube 122 is mounted
to the base housing 16 via a support platform 182. That is, the
support platform 182 is mounted on the base housing 16 to support
the outlet tube 122 on the base housing 16. The support platform
182 includes at least one tube slot 184. The at least one tube slot
184 houses the diameter of the outlet tube 122. The outlet tube 122
is mounted in the tube slot 184 such that at least a portion, not
numbered, of the diameter of the outlet tube 122 is exposed to the
detection film 180.
[0126] The detection film 180 is disposed between the electronic
controller 118 and the outlet tube 122. The detection film 180 is
in contact with the outlet tube 122 and remains spaced from the
electronic controller 118 when the diameter of the outlet tube 122
is in the normal condition, as in FIG. 15A. On the other hand, the
detection film 180 is in contact with the outlet tube 122 and
contacts the electronic controller 118 to activate the electronic
controller 118 when the diameter of the outlet tube 122 is in the
expanded condition, as in FIG. 15B, in response to increased
pressure resulting from the blockage in the flow of the medication
to the patient 12. More specifically, it is preferred that an
electronic switch 186 is embedded in the electronic controller 118
between the electronic controller 118 and the detection film 180.
The detection film 180 interacts with the electronic controller 118
by contacting the electronic switch 186 to activate the electronic
controller 118 when the diameter of the outlet tube 122 is in the
expanded condition.
[0127] For activating the electronic controller 118 when the
diameter of the outlet tube 122 is in the expanded condition, it is
also preferred that the detection film 180 is conductive. Once
activated by the detection film 180, the electronic controller 118
deactivates the pump assembly 28 to prevent delivery of the
medication to the patient 12 when the diameter of the outlet tube
122 is in the expanded condition. Deactivation of the pump assembly
28 prevents further blockage and further increases in pressure. To
properly ensure that the there is a blockage in the outlet tube
122, it is most preferred that the electronic controller 118, and
therefore the pump assembly 28, are deactivated only if the
diameter of the outlet tube 122 is in the expanded condition for
more than at least one cycle of the pump assembly 28. This
additional measure avoids false readings and the deactivation of
the pump assembly 28 when the outlet tube 122 is truly not
blocked.
[0128] Additionally, once activated by the detection film 180, the
electronic controller 118 may also activate an alarm 188, shown
schematically in the Figures. The alarm 188, which can be audible
and/or visually displayed on the electronic display 174, would
indicate the blockage that is due to the blockage in the flow of
the medication to the patient 12.
[0129] It is preferred that the detection film 180 is mounted to
the electronic controller 118. Although the detection film 180 is
mounted to the electronic controller 118, a portion, not numbered,
of the detection film 180 remains at least partially-spaced from
the electronic controller 118 when the diameter of the outlet tube
122 is in the normal condition. The detection film 180 is mounted
to the electronic controller 118 with an adhesive layer 190. The
adhesive layer 190 also establishes a thickness that is necessary
to space the detection film 180, specifically the portion of the
detection film 180, from the electronic controller 118 when the
diameter of the outlet tube 122 is in the normal condition. The
portion of the detection film 180 contacts the electronic
controller 118 to activate the electronic controller 118 when the
diameter of the outlet tube 122 is in the expanded condition in
response to increased pressure in the outlet tube 122.
[0130] An alternative embodiment for the blockage detection system
178 is disclosed in FIG. 17. In this alternative embodiment, the
detection film 180 is eliminated, and a coating 192 is included.
The coating 192 is applied to the outlet tube 122. The coating 192
activates the electronic controller 118 when the diameter of the
outlet tube 122 is in the expanded condition in response to
increased pressure resulting from the blockage in the flow of the
medication to the patient 12. As with the detection film 180, the
coating 192 is preferably conductive. If the coating 192 is
present, it is most preferred that the coating 192 is formed of
conductive carbon. However, other coatings may be used that impart
conductive properties to the coating 192.
[0131] For the most part, the other characteristics of this
alternative embodiment for the blockage detection system 178 are
identical to the characteristics that were described above in the
preferred embodiment for the blockage detection system 178.
Notably, the outlet tube 122 is mounted in the tube slot 184 in
this alternative embodiment such that at least a portion of the
coating 192 is exposed beyond the tube slot 184.
[0132] The subject invention also provides an empty detection
system which is generally disclosed at 194 in FIGS. 16A-16B. The
empty detection system 194 determines when a supply of the
medication has been depleted. The empty detection system 194
comprises the base housing 16, the reservoir 24 for storing the
supply of the medication to be delivered to the patient 12, the
port 82, the pump assembly 28, the medication inlet tube 120, and
the electronic controller 118. As with the blockage detection
system 178, the preferred embodiment of the empty detection system
194 also includes a detection film, also numbered 180, which is
described below.
[0133] In the empty detection system 194, the electronic controller
118 is mounted to the base housing 16 adjacent the inlet tube 120.
The inlet tube 120 is mounted to the base housing 16 and, as
described above, is connected between the reservoir 24 and the pump
assembly 28 to provide access for the medication to flow from the
reservoir 24 into the pump assembly 28 and to the patient 12. The
inlet tube 120 has a diameter that is contractible and expandable
between a normal condition (see FIG. 16A) and a collapsed condition
(see FIG. 16B). The inlet tube 120 contracts into the collapsed
condition and expands from the collapsed condition into the normal
condition. The diameter of the inlet tube 120 contracts and expands
in response to variations in pressure that result from a lack of
the flow of the medication from the reservoir 24 through the pump
assembly 28 and to the patient 12.
[0134] As disclosed in the Figures, the inlet tube 120 is mounted
to the base housing 16 via the support platform 182. That is, the
support platform 182 is mounted on the base housing 16 to support
the inlet tube 120 on the base housing 16. The support platform 182
includes the at least one tube slot 184. The at least one tube slot
184 houses the diameter of the inlet tube 120. The inlet tube 120
is mounted in the tube slot 184 such that at least a portion of the
diameter of the inlet tube 120 is exposed to the detection film
180.
[0135] The detection film 180 is disposed between the electronic
controller 118 and the inlet tube 120. As shown in FIG. 16A, the
detection film 180 is in contact with the inlet tube 120 and
contacts the electronic controller 118 to activate the electronic
controller 118 when the diameter of the inlet tube 120 is in the
normal condition. On the other hand, as shown in FIG. 16B, the
detection film 180 becomes spaced from the electronic controller
118 to deactivate the electronic controller 118 when the diameter
of the inlet tube 120 is in the collapsed condition in response to
the lack of flow of the medication that results from the supply of
the medication being depleted.
[0136] It is preferred that an electronic switch 186 is embedded in
the electronic controller 118 between the electronic controller 118
and the detection film 180. The detection film 180 contacts the
electronic switch 186 to activate the electronic controller 118
when the diameter of the inlet tube 120 is in the normal condition,
and the detection film 180 becomes spaced from the electronic
switch 186 to deactivate the electronic controller 118 when the
diameter of the inlet tube 120 is in the collapsed condition.
[0137] As best disclosed in FIG. 4, the detection film 180 more
specifically includes a film base portion 196 and a cantilever
portion 198. The film base portion 196 of the detection film 180 is
mounted to the electronic controller 118 away from the electronic
switch 186, and the cantilever portion 198 of the detection film
180 is adjacent the electronic switch 186. More specifically, the
cantilever portion 198 extends from the film base portion 104 to
contact the electronic switch 186 when the diameter of the inlet
tube 120 is in the normal condition. It is the cantilever portion
198 of the detection film 180 that becomes spaced from the
electronic controller 118 to deactivate the electronic controller
118 when the diameter of the inlet tube 120 is in the collapsed
condition. For activating the electronic controller 118 when the
diameter of the inlet tube 120 is in the normal condition, it is
also preferred that the detection film 180, specifically the
cantilever portion 198 of the detection film 180, is conductive.
Preferably, the detection film 180 is mounted to the electronic
controller 118 with an adhesive layer 190. Of course, it is the
film base portion 196 of the detection film 180 that is directly
mounted to the electronic controller 118. The cantilever portion
198 of the detection film 180 is not directly mounted, or otherwise
adhered, to the electronic controller 118 such that this portion of
the detection film 180 can become spaced from the electronic
controller 118 when the diameter of the inlet tube 120 is in the
collapsed condition.
[0138] Once the detection film 180 becomes spaced from the
electronic controller 118, i.e., when the diameter of the inlet
tube 120 is in the collapsed condition, the portion of the
electronic controller 118 that interacts with the pump assembly 28
is deactivated such that the pump assembly 28 is deactivated.
Deactivation of the pump assembly 28 after it has been determined
that the supply of the medication has been depleted prevents a
build up of air in the system. To properly ensure that the supply
of the medication has been depleted, it is most preferred that the
electronic controller 118, and therefore the pump assembly 28, are
deactivated only if the diameter of the inlet tube 120 is in the
collapsed condition for more than at least one cycle of the pump
assembly 28. This additional measure avoids false readings and the
deactivation of the pump assembly 28 when the supply of the
medication is truly not depleted.
[0139] Additionally, deactivation of the portion of the electronic
controller 118 that interacts with the pump assembly 28 may also
cause the electronic controller 118 to activate the alarm 188. The
alarm 188, which can be audible and/or visually displayed on the
electronic display 174, would indicate the lack of flow of the
medication when the diameter of the inlet tube 120 is in the
collapsed condition due to the lack of flow of the medication to
the patient 12.
[0140] An alternative embodiment for the empty detection system 194
is disclosed in FIG. 17. In this alternative embodiment, the
detection film 180 is eliminated, and the coating 192 is included.
The coating 192 is applied to the inlet tube 120. The coating 192
contacts the electronic controller 118 to activate the electronic
controller 118 when the diameter of the inlet tube 120 is in the
normal condition. On the other hand, the coating 192 becomes spaced
from the electronic controller 118 to deactivate the electronic
controller 118 when the diameter of the inlet tube 120 is in the
collapsed condition in response to the lack of flow of the
medication resulting from the supply of the medication being
depleted. As with the detection film 180, the coating 192 is
preferably conductive. If the coating 192 is present, it is most
preferred that the coating 192 is formed of conductive carbon.
However, other coatings may be used that impart conductive
properties to the coating 192.
[0141] For the most part, the other characteristics of this
alternative embodiment for the empty detection system 194 are
identical to the characteristics that were described above in the
preferred embodiment for the empty detection system 194. Notably,
the inlet tube 120 is mounted in the tube slot 184 in this
alternative embodiment such that at least a portion of the coating
192 is exposed beyond the tube slot 184.
[0142] Referring now to FIGS. 1B, 6A-6D, and 18A-18B, the system 10
of the subject invention can be tested using a testing instrument
200 after assembly of the system 10. The system 10 is tested after
assembly and prior to shipment and use by the surgeons, patients,
and the like to confirm various operations of the system 10. In the
preferred embodiment, to test the system 10, the system 10 is
mounted onto the testing instrument 200. One operation of the
system 10 that is confirmed after assembly of the system 10 is the
operation of the pump assembly 28.
[0143] To confirm these operations, the system 10 includes at least
one testing access port 202. The at least one testing access port
202 is defined within the base housing 16 and is aligned with at
least one of the pump inlet 32, the pump outlet 34, and the
actuator 102. Preferably, the at least one testing access port 202
is aligned with all three of the pump inlet 32, the pump outlet 34,
and the actuator 102. The at least one testing access port 202
provides access for the testing instrument 200 to move the actuator
102 between the disengaged position and the engaged position. If
the at least one testing access port 202 is aligned with the pump
inlet 32 and the pump outlet 34 then it is aligned with the first
and second pinch levers 38, 40, respectively. Also, as for the
alignment with the actuator 102, the at least one testing access
port 202 is more specifically aligned with the at least one
engagement arm 106 of the actuator 102. This provides access for
the testing instrument 200 to move the actuator 102 between the
disengaged position and the engaged position.
[0144] The system 10 is preferably assembled with the actuator 102
in the engaged position such that the first and second pinch levers
38, 40 are in the open position and the resiliency and life of the
medication inlet and outlet tubes 120, 122 is not compromised.
Because the at least one testing access port 202 provides access
for the testing instrument 200 to move the actuator 102 between the
disengaged position and the engaged position, the testing
instrument 200 can be inserted into the at least one testing access
port 202 to disengage the actuator 102, i.e., to move the actuator
102 into the disengaged position. As such, the pump inlet 32 and
the pump outlet 34 can alternate between the open and closed states
after assembly and during testing of the system 10.
[0145] The at least one testing access port also provides access
for the testing instrument 200 such that the pump inlet 32 and the
pump outlet 34 can be retained in the open state after the system
10 has been tested to prepare the system 10 for sterilization. That
is, after the system 10 has been tested, the actuator 102 is moved
from the disengaged position back into the engaged position to
prepare the system 10 for sterilization. In the engaged position,
the first and second pinch levers 38, 40 are retained in the open
state.
[0146] In the preferred embodiment, the at least one testing access
port 202 is further defined as first, second, and third testing
access ports 204, 206, 208, respectively. The first testing access
port 204 is aligned with the pump inlet 32, the second testing
access port 206 is aligned with the pump outlet 34, and the third
testing access port 208 is aligned with the actuator 102 for
providing access to the testing instrument 200 to move the actuator
102 into the engaged position. More specifically, the first testing
access port 204 is aligned with the first pinch lever 38 such that
the first pinch lever 38 is engaged by the testing instrument 200.
Once inside the first testing access port 204, the testing
instrument 200 forces the first pinch lever 38 away from the pump
inlet 32 and forces the pump inlet 32 into the open state.
Similarly, the second testing access port 206 is aligned with the
second pinch lever 40 such that the second pinch lever 40 is
engaged by the testing instrument 200. Once inside the second
testing access port 206, the testing instrument 200 forces the
second pinch lever 40 away from the pump outlet 34 and forces the
pump outlet 34 into the open state. The first and second pinch
levers 38, 40 include the lever guides 78 opposite the cam follower
76 of each pinch lever 38, 40. To move the first and second pinch
levers 38, 40, the testing instrument 200 engages the lever guides
78 upon insertion into the first and second testing access ports
204, 206. After the testing instrument 200 forces the first and
second pinch levers 38, 40 away from the pump inlet 32 and the pump
outlet 34, respectively, the testing instrument 200 is introduced
into the third testing access port 208 and the actuator 102 is
moved into the engaged position to engage and retain the pinch
levers 38, 40 in the open position such that the system 10 is now
prepared for sterilization. It is to be understood by those skilled
in the art that the testing instrument 200 includes male prongs,
generally indicated at 210, that are introduced into the testing
access ports 204, 206, 208.
[0147] The system 10 further includes at least one controller
access port 212 defined within the base housing 16. In the
preferred embodiment, the at least one controller access port 212
is defined within the top housing 22 or cover. The at least one
controller access port 212 is aligned with the electronic
controller 118 to provide access for a second testing instrument
214. It is to be understood that the second testing instrument 214
and the testing instrument 200 may be a unitary component, as
disclosed in the Figures. The second testing instrument 214 causes
the electronic controller 118 to activate the motor 42 such that
the motor 42 is powered to alternate the pump inlet 32 and the pump
outlet 34 between the open and closed states after assembly and
during testing of the system 10. The second testing instrument 214
also preferably includes male prongs 210 that are introduced into
the controller access ports 212.
[0148] Referring primarily to FIGS. 2A-3, and 19-20, the system 10
of the subject invention is also suitable to be carried by the
patient 12. To facilitate carrying of the system 10 so the patient
12 can remain ambulatory, a carrying strap 216 is mounted within
the base housing 16 for the carrying of the system 10 by the
patient 12. An integral storage cavity 218 is defined within the
base housing 16. The carrying strap 216 is at least partially
disposed in the integral storage cavity 218. The carrying strap 216
at least partially extends from the integral storage cavity 218 to
interact with the patient 12 for carrying the system 10.
[0149] The system 10 further includes a plurality of cavity walls.
The cavity walls extend from the bottom housing 18 to define the
integral storage cavity 218 between the bottom 18 and top 22
housings. Referring particularly to FIG. 20, the cavity walls are
further defined as a front wall 220, a rear wall 222, and first and
second side walls 224 extending between the front and rear walls
220, 222 to support the front and rear walls 220, 222 and to define
the integral storage cavity 218. At least one strap slot 226 is
defined within the front wall 220 such that at least a portion, not
numbered, of the carrying strap 216 extends from the integral
storage cavity 218 and through the strap slot 226. The patient 12
can then access the portion of the carrying strap 216 when
desired.
[0150] In interacting with the carrying strap 216, the patient 12
simply manipulates, or grabs, the portion of the carrying strap 216
to pull a length of the carrying strap 216 from the integral
storage cavity 218. This length is then looped about the head of
the patient 12 as specifically disclosed in FIG. 19. In the
preferred embodiment, the carrying strap 216 is retractable into
the integral storage cavity 218 after the length has been pulled
from the integral storage cavity 218 by the patient 12. The system
10 further includes a clip 228 that connects opposing ends of the
carrying strap 216 such that the carrying strap 216 is adjustable
to fit patients 12 of all sizes. In the most preferred embodiment
of the subject invention, which is disclosed in FIG. 19, the
carrying strap 216 is further defined as a shoulder strap. The
shoulder strap suspends from a shoulder of the patient 12 for
carrying the system 10.
[0151] Also, as particularly disclosed in FIG. 1B, the system 10
may also further include a system mounting clip 230 that extends
from an exterior facing 232 of the base housing 16. The system
mounting clip 230 can be mounted to a belt 234 of the patient 12.
Of course, it is to be understood that the system mounting clip 230
is not to be limited to a clip for a belt 234. Instead, the system
mounting clip 230 may be mounted to a shirt, a pocket, and the
like.
[0152] Referring to FIGS. 2B, and 21-24, the subject invention
further provides a method of controlling the system 10. This method
is designed to be convenient for both the surgeon, or other medical
professional, and the patient 12. A patient label 236, having a
second set of explanatory indicia, i.e., instructions, is mounted,
preferably adhered, to the system 10. A removable overlay label
238, having a first set of explanatory indicia, i.e., instructions,
is mounted, preferably adhered, to the patient label 236 to at
least partially cover the patient label 236.
[0153] The method includes the steps of selecting the amount of the
medication in accordance with the first set of explanatory indicia
on the removable overlay label 238. The medical professional
selects the amount of the medication. As such, the first set of
explanatory indicia is intended to be readily understood by the
medical professional. Typically, the amount of the medication is
selected by selecting the flow rate for the medication. Other
parameters including, but not limited to, the bolus amount, the
drug or medication concentration, and like, can also be
selected.
[0154] Throughout the step of selecting, the medical professional
and/or patient 12 interfaces with the electronic display 174 to
view his or her selections. More specifically, the electronic
display 174 presents a readable output for the medical professional
and the patient 12. The readable output displayed on the electronic
display 174 is correlated with the removable overlay label 238 and
the patient label 236. That is, the readable output is correlated
to the first and second sets of instructions. A first readable
output is presented on the electronic display 174. The first
readable output is linked with the first set of explanatory indicia
when the removable overlay label 238 is displayed. Similarly, a
second readable output is presented on the electronic display 174.
The second readable output is linked with the second set of
explanatory indicia after the system 10 has been locked. Locking
the system 10 is described immediately below.
[0155] After the amount of the medication has been selected, the
system 10 is locked such that selected amount of the medication to
be delivered to the patient 12 is unable to be modified. After the
medical professional is satisfied with his or her selection, the
medical professional depresses the "LOCK" portion of the first set
of explanatory indicia on the removable overlay label 238 to lock
the system 10.
[0156] Once the system 10 is locked, either the medical
professional or the patient 12 can remove the removable overlay
label 238 to reveal the patient label 236 (as shown in FIG. 21). To
accomplish this, the user, either the medical professional or the
patient 12, simply pulls the removable overlay label 238 off the
patient label 236. This reveals the control button 176 that was
originally masked under the removable overlay label 238. The system
10 is then operated in accordance with a second set of explanatory
indicia on the patient label 236. The second set of explanatory
indicia is intended to be readily understood by the patient 12.
Once the system 10 is locked, the system 10 is designed to be
convenient for use by the patient 12.
[0157] Upon locking the system 10, a functionality of the control
button 176 is modified. As such, the functionality of the control
button 176 is different when the removable overlay label 238 is
displayed on the system 10 as compared to when the patient label
236 is displayed on the system 10. In other words, the
functionality of the control button 176 is different when the
medical professional interacts with the system 10 via the removable
overlay label 238 as compared to when the patient 12 interacts with
the system 10 via the patient label 236. When the removable overlay
label 238 is displayed on the system 10, the control button 176 is
at least tri-functional. On the other hand, after the system 10 has
been locked and the patient label 236 is displayed on the system
10, the functionality of the control button 176 is converted from
being at least tri-functional to being bi-functional.
[0158] In operating the system 10, the system 10 may be
deactivated, if necessary, to stop delivery of the medication to
the patient 12. To deactivate the system 10, the patient 12
depresses the "ON/OFF" portion of the, now bi-functional, control
button 176 in response to the second set of explanatory indicia on
the patient label 236. If the system 10 is deactivated, then the
patient 12 may also use the control button 176 to activate the
system 10 to re-start delivery of the medication to the patient 12.
To accomplish this, the patient 12 depresses the "ON/OFF" portion
of the control button 176 again.
[0159] Alternatively, in operating the system 10, the patient 12
may request an additional amount of the medication relative to the
selected amount of the medication, and provided the Bolus amount
will not be violated, the patient 12 will receive an additional
amount of the medication. To request an additional amount of the
medication relative to the selected amount, the patient 12 actuates
the control button 176.
[0160] With specific reference to FIG. 25, a control system 240 for
the system 10, according to an embodiment of the present invention
is shown. The control system 240 includes the electronic controller
118 and a motor control circuit 242. The electronic controller 118
controls operation of the system 10 as described above.
[0161] In one embodiment, the electronic controller 118 includes a
microprocessor 244. One suitable microprocessor 244 is available
from Philips Semiconductor of Sunnyvale, Calif. as model no.
87LPC764. The electronic controller 118 is programmed to control
operation of the motor control circuit 242 with a computer software
program. In general, the electronic controller 118 generates
control signals in accordance with the computer software program
and delivers the control signals to the motor control circuit
242.
[0162] The motor control circuit 242 includes a first switch 246.
The first switch 246 has an open state and a closed state.
[0163] The control system 240 also includes a watchdog circuit 248
coupled to the electronic controller 118. The watchdog circuit 248
includes a monitor circuit 250 and a second switch 252. The second
switch 252 has an open state and a closed state and is coupled to
the first switch 246. The monitor circuit 250 is adapted to detect
an abnormal condition of the control system 240 and to turn the
second switch 252 off if the abnormal condition is detected.
Examples of an abnormal condition include, but are not limited to,
too many revolutions of the motor 42, failure of the electronic
controller 118, failure of the first switch 246, or failure of a
motor sensor 254 (see below).
[0164] The motor control circuit 242 is adapted to receive control
signals from the electronic controller 118 and to responsively
supply power to the motor 42 by placing the first switch 246 in the
closed state. Power is supplied to the motor 42 if the first and
second switches 246, 252 are in the closed state.
[0165] With reference to FIGS. 26 and 27, in one embodiment the
first and second switches 246, 252 are field effect transistors
(FETs) 256, 258. In one embodiment, the control system 240 includes
the control buttons 176. A user such as the surgeon or the patient
12 is able to program the control system 240 to deliver medication
at the desired flow rate. Based on the desired flow rate, the
electronic controller 118 controls energization of the motor 42 to
deliver the medication.
[0166] In one embodiment, each revolution of the motor 42 delivers
a set amount of the medication during a known period of time. A
predetermined number of revolutions of the motor 42 delivers a
"pulse" of medication. In order to meet the desired flow rate, the
electronic controller 118 calculates a period of time between
revolutions of the motor 42.
[0167] In one embodiment of the present invention, the period of
time calculated by the controller 118 (between pulses) is constant
fixed for the desired flow rate.
[0168] In one aspect of the present invention, the controller 118
controls the pump assembly 28 to provide a series of pulses of
medication to provide the desired flow of medication. With
reference to FIGS. 28, 29A, 29B, and 29C, the fluid flow output of
the system 10 may be subdivided. As shown, the fluid flow from the
tube set 14 may be divided by a flow divider 288 to provide fluid
flow to a plurality of legs 290. In the illustrated embodiment,
there are n legs each having a respective fluid flowrate of {dot
over (M)}.sub.n.
[0169] In one embodiment, the series of pulses are determined to
provide an outlet pressure at the pump outlet adapted to reduce the
effect of any differential pressure between the legs. In other
words, a differential pressure across two legs, e.g., Leg 1 and Leg
2, may result in a differential flow rate through each leg. The
controller 118 manipulates the pulses to maintain the total
pressure through the tube set 14 high enough for a long enough
period of time to reduce the effect of the differential pressure at
the legs. For example, the pulses may be spaced together closely
enough so that each pulse begins before a significant drop in fluid
pressure level occurs following the previous pulse.
[0170] With reference to FIG. 29A in another aspect of the present
invention, the controller 118 controls the pump assembly 28 to
provide groups 292 of pulses. In one embodiment, the number of
pulses in a group 292 is predetermined. For exemplary purposes
only, first and second groups 292A, 292B are shown with eight
pulses each. A first time period, t1, separates the start of each
pulse within a group 292 and a second time period, t2, separates
the start of each group. The first and second time periods may be
determined by the controller 118 to provide the desired flow rate
while maintaining the desired flow through each leg 290 and
reducing the effect of any pressure differential. For example, the
number of pulses in each group 290 may be 10, the first time period
may be equal to 1.8 seconds and the second time period may be 100
to 1300 seconds. Of course, the numbers are for explanation
purposes only. The present invention is not limited to any such
examples.
[0171] In another embodiment, the first time period is fixed and
the controller 118 determines the second period as a function of
the desired fluid flow.
[0172] In another aspect of the present invention, a method for
delivering medication using a medication delivery system 10
including the steps of storing a supply of medication, receiving a
desired flow of medication, and providing a flow of medication from
the supply of medication in the form of a series of pulses. The
flow is provided through an outlet and is subdivided into a
plurality of legs 290. The series of pulses are determined to
provide an outlet pressure at the pump outlet adapted to reduce an
effect of any differential pressure between the legs.
[0173] Since a higher pulse frequency may lead to an average flow
rate during pulsing that is higher than the desired flow rate, the
pulses may be delivered in groups of a given number of pulses (see
above); the time elapsing between each group may be set as a
function of the overall time-averaged flow rate desired from the
pump (see above). This grouping of pulses can negatively affect the
flow distribution to the various sites because the final pulse in a
group will conclude with an asymptotic pressure drain during which
the flow balance degrades as the pressure drops. To compensate for
this, a group size may be selected so that the amount of flow
occurring during the steady-state period of intermittent pulsing
will sufficiently reduce the effect of the imbalanced flow that
happens subsequent to the final pulse. With reference to FIGS. 29B
and 29C, a representative sketch of a pressure profile during a
group of pulses is shown. Pcritical represents a pressure level
above which acceptable flow distribution may be assured. This value
is dependent upon the desired level of accuracy and the level of
variation in the outlet pressures.
[0174] The pump pulse method described above controls pressure and
provides good flow splitting characteristics. In one embodiment of
the present invention, the flow divider 288 may be designed to, in
conjunction with the pump pulse method described above, to provide
back pressure assistance, anti-siphon characteristics, and
controlled restriction.
[0175] With reference to FIG. 29D, in one aspect of the present
invention, the flow divider 288 includes a valve system 294 which
provides flow restriction and anti-siphoning components to control
flow split. In the illustrated embodiment, the valve system 294
includes two legs each leading to an extended fenestration catheter
296.
[0176] As shown, in the illustrated embodiment, the infusion tube
set 14 includes a priming adapter 294A, an on/off clamp 294B, and a
filter 294C. A divider, shown as a Y-connector, 294D is coupled to
the filter 294C.
[0177] Each leg of the infusion set 14 after the Y-connector may
include one or more low resistance, low cracking check valves 294E.
The check valves 294E alleviates the siphoning problems during
inactivity of the pump assembly 28 (see above).
[0178] Although the pressure deteriorates nearly to zero after the
last pulse in a group, the number of pulses and the spacing of the
pulses in a group may be determined so that the average pressure is
great enough to provide adequate distribution of flow to each leg
(see FIG. 29B and discussion above).
[0179] Each leg may also include a flow restrictor 294F. In the
illustrated embodiment, the flow restrictors 294F are coupled to
one of the check valves 294E. The flow restrictors 294F have an
orifice (not shown) with a predetermined flow restriction value.
The predetermined flow restriction value may be coordinated with
the average flow rate during a group of pulses to keep the average
pressure differential at a desired level for flow balance.
[0180] With reference to FIGS. 30-36, in another aspect of the
present invention, the infusion tube set 14 may include a multiple
site infusion apparatus 310. The multiple site infusion apparatus
310 may be coupled to an output tube 312 of the system 10 to split
the medication delivered from the delivery system 10 and deliver
the medicine through first and second outlet passageways 314A,
314B. In the illustrated embodiment, the apparatus 310 is shown as
a two site infusion apparatus 310, however, it should be noted that
the present invention may provide medicine to a plurality of
sites.
[0181] The apparatus 310 includes a valve housing 316. The valve
housing 316 includes a first end 318 and a second end 320. The
first end 318 includes the first and second outlet passageways
314A, 314B.
[0182] An end cap 330 has a closed end 332 and an open end 334. The
end cap 330 is coupled to the valve housing 316 at the open end
334. A flexible diaphragm 336 is coupled between the end cap 330
and the valve housing 316 and is movable from a closed position to
and an open position by the fluid energy of the pulse. The second
end 320 of the valve housing 316 and the flexible diaphragm 336
form a pressure chamber 322. The valve housing 316 further includes
an inlet passageway 324. The inlet passageway 324 is coupled to the
pressure chamber 322. The first and second outlet passageways 314A,
314B are coupled to the pressure chamber 322 by first and second
outlet conduits 328A, 328B, respectively. The flexible diaphragm
336 seals the pressure chamber 322 from the first and second outlet
conduits 328A, 328B when the flexible diaphragm 336 is in the
closed position and opens the first and second outlet conduits
328A, 328B to the pressure chamber 322 when the flexible diaphragm
336 is in the open position.
[0183] The valve housing 316 also includes a routing passageway 326
adjacent the inlet passage 324. The routing passageway 326 allows
the medication delivery system inlet tube 312 to be secured within
the valve housing 316. In one embodiment of the present invention,
the end of the inlet tube 312 coated with a solvent and inserted
through the inlet of passageway 324. The inlet passageway 324 and
the output tube 312 have an interference fit. The solvent bonds the
inlet tube 312 and the inlet passageway 324.
[0184] As shown, in one embodiment of the present invention, the
open end 334 of the cap 330 has an outer perimeter 338. The outer
perimeter 338 includes a ridge 340. The second end 320 of the valve
housing 316 includes a detent 342 along its outer perimeter 344.
The detent 342 receives the ridge 340 which allows the valve
housing 316 and the end cap 330 to be snapped together.
[0185] In another aspect of the present invention, the apparatus
310 includes a biasing mechanism 344 coupled between the cap 330
and the flexible diaphragm 336 for biasing the flexible diaphragm
336 towards the closed position. In one embodiment of the present
invention, the biasing mechanism 344 includes a biasing spring 346.
The biasing spring 346 may be either tubular or conical.
[0186] In another aspect of the present invention, a piston 348 may
be juxtaposed between the biasing spring 346 and the flexible
diaphragm 336. In one embodiment, the flexible diaphragm 336
includes a piston receiving aperture 350 for receiving a first end
352 of the piston 348.
[0187] As shown, in one embodiment, the piston 348 is hollow and
includes a spring receiving chamber 354. The end cap 330 includes a
spring positioning pin 356. One end of the spring 346 is seated
within the spring receiving chamber 354 and the other end is
centered on the spring position pin 356.
[0188] In another aspect of the present invention, the apparatus
310 includes first and second bushings 358A, 358B which are located
within and have an interference fit with the first and second
outlet passageway 314A,314B. First and second restriction orifices
360A, 360B are positioned within and have an interference fit with
the first and second bushings 358A, 358B, respectively. Flexible
outlet tubes (not shown) are coupled to the passageways 314A, 314B
to deliver medication to the sites, as needed.
[0189] In one aspect of the present invention, the inner diameter
of the orifice 360A, 360B are relatively small, e.g., 0.001 to
0.005 inches with a small manufacturing tolerance. The orifices
360A, 360B are dimensioned to provide a large resistance to the
flow of medication relative to resistance provided by the flexible
outlet tubes and the sites where the medication is delivered. This
assists in controlling the back pressure and thus minimizing the
risk of an unequal amount of medication to be delivered to the two
sites.
[0190] In another aspect of the present invention, the flexible
diaphragm 336 includes an integrally molded O-ring 362 around its
outer perimeter 364. The O-ring 362 is press fit within a circular
groove 366 in the valve housing 316. The valve housing 316 includes
one or more air release apertures 368 which allow air to escape the
groove 366 as the O-ring 362 is pressed into the groove 366. The
O-ring 362 and the groove 366 ensures that the outer perimeter 364
is coupled to the valve housing, thereby forming the pressure
chamber 322.
[0191] In operation, the medication delivery system delivers
medication through the inlet tube 312 in pulses. With reference to
FIG. 35, when the flexible diaphragm 336 is in the closed position,
the flexible diaphragm 336 creates a seal on the outlet valve
seats. As fluid is pumped in, a pressure is created (Pinlet) within
the pressure chamber 322. With the flexible diaphragm 336 in the
closed position, no flow of medication is allowed from the pressure
chamber 322 to the output passageways 314A, 314B. Thus, while the
flexible diaphragm 336 is in the closed position, the pressure at
the outlet conduits 328A, 328B (Poutlet) is substantially zero.
[0192] When the "pulse" of medication from the medication delivery
system begins, Pinlet quickly ramps up from a non-zero value. When
the force exerted by the pressurized medication within the pressure
chamber 322 on the flexible diaphragm 336 is great enough to
overcome the force exerted by the biasing mechanism 344, the
flexible diaphragm 336 is moved from the closed position towards
the open position. After the flexible diaphragm 336 is moved away
from the closed position, fluid flows out of the valve and pressure
decays down towards a non-zero value until the force exerted by the
biasing mechanism 344 overcomes the force exerted on the flexible
diaphragm by the medication within the pressure chamber 322 such
that the diaphragm closes over the passageways 314A, 314B. The rate
of fluid flow and therefore pressure decrease is controlled by the
restrictors 360A, 360B. This control is important since too low of
a restriction would not force a complete opening of the valve. In
that case the restriction of flow across the valve seats would be
significant and minor variations in manufacturing tolerances and/or
finishes would control the flow resistance and resultant
distribution. With proper flow restrictor selection, the apparatus
310 fully opens and this does not occur.
[0193] Likewise, when the flexible diaphragm 36 is moved away from
the closed position, Poutlet (in conduits 328A, 328B) quickly ramps
up to a pressure substantially equal to or slightly less than
Pinlet. While the flexible diaphragm 336 is open, Pinlet tracks
Poutlet. Since the resistance seen within the first and second
passageways 314A, 314B is a result of the resistance of the first
and second orifices 360A, 360B, Poutlet at the first and second
outlet passageways 314A, 314B are substantially equal. Once the
flexible diaphragm 336 closes, Poutlet quickly drops back down to
substantially zero.
[0194] The pulsing method discussed above may be used in
applications in which the medication delivery system 10 delivers
medicine to more than one site. The pulsing method may be used to
control pressure and to facilitate the desired flow splitting
characteristics. Additionally, the infusion tube set 14 may include
enhanced features to provide controlled restriction and
anti-siphoning characteristics. As described above, in one
embodiment the infusion tube set 14 includes check valves and flow
restrictors to provide the desired characteristics. In another
embodiment, the infusion tub set includes the multiple site
infusion apparatus 310.
[0195] Returning to FIGS. 4 and 5, in one embodiment, the motor
control circuit 242 includes the motor sensor 254 (see FIG. 4). The
motor sensor 254 is coupled to the motor 42 and is adapted to
detect a revolution of the motor 42 and to responsively generate a
motor revolution signal in response to completion of the motor 42
revolution. In one embodiment, the motor sensor 254 is a
opto-coupler sensor which is adapted to detect the presence of an
indicating flag 260 (see FIG. 5) connected to the motor 42. The
indicating flag 260 extends from one of the first and second
outside cams 64, 66 to assist in monitoring the amount of the
medication that has been delivered to the patient 12. The sensor
254 is optically-coupled with the indicating flag 260 to count
revolutions of the indicating flag 260. One suitable sensor 254 is
available from Omron of Schaumburg, Ill., as model no.
EE-SX1109.
[0196] In one embodiment, the electronic controller 118 is adapted
to reset the watchdog circuit 248 prior to sending control signals
to the motor 42 control circuit to energize the motor 42. The
watchdog circuit 248 is adapted to place the second switch 252 in
the opened state if two motor revolution signals are received
without the watchdog circuit 248 being reset.
[0197] In other words, the electronic controller 118 must reset the
watchdog circuit 248 prior to or between each revolution of the
motor 42. Thus, if a failure of the electronic controller 118 or
the microprocessor 244 erroneously causes a control signal to be
delivered to the motor control circuit 242 to continuously place
the first switch 246 in the closed state, and thus, to erroneously
energize the motor 42, the second switch 252 will be placed in the
opened state. With the second switch 252 in the opened state, power
will not be delivered to the motor 42.
[0198] Additionally, if a failure of the first switch 246 leaves
the first switch 246 in the closed state, successive motor
revolution signals will be received by the watchdog circuit 248
without the watchdog circuit 248 being reset and the watchdog
circuit 248 will place the second switch 252 in the opened state,
thus preventing power from being supplied to the motor 42.
[0199] In one embodiment, the electronic controller 118 is adapted
to track the time after a motor control signal has been sent and to
enter a disabled state if the time between the sent control signal
and received motor revolution signal exceeds a predetermined
threshold.
[0200] With specific reference to FIG. 26, in one embodiment the
monitor circuit 248 includes first and second flip-flops 262, 264.
The first flip-flop 262 is coupled to the electronic controller 118
and the second flip-flop 264. The second flip-flop 264 is coupled
to the second FET 258.
[0201] In the illustrated embodiment, the first and second
flip-flops 262, 264 are JK flip-flops. The inverse output (Q) of
the second flip-flop 264 is connected to the gate of the second FET
258. The clock input (CLK) of the second flip-flop 264 is coupled
to the output (Q) of the first flip-flop 262. Power is supplied by
the microprocessor 244 to the first and second flip-flops 262, 264
to the J and K inputs of the first flop 262 and to the J input of
the second flip-flop 264. The drain of the second FET 258 is
coupled to the first FET 256 and the source of the second FET 258
is connected to electrical ground.
[0202] The watchdog circuit 248 is reset by shutting off and
restoring power to the first and second flip-flops 262, 264, to the
J and K inputs of the first flop 262, and to the J input of the
second flip-flop 264. In one embodiment, the electronic controller
118 shuts off power to the first and second flip-flops 262, 264
after each revolution of the motor 42 and supplies power prior to
turning on the first switch 246 to begin the next cycle. This has
two effects: conserving power and resetting the first and second
flip-flops 262, 264.
[0203] The clock input (CLK) of the first flip-flop 262 is
connected to the output of the motor sensor 254. The clock input
(CLK) of the first flip-flop 262 is also connected to the
microprocessor 244 via a third FET 266. The third FET 266 provides
isolation between the microprocessor 244 and the motor sensor 254
and the monitor circuit 248. This isolation prevents a shorted pin
on the electronic controller 118 from preventing revolution pulses
from reaching the flip-flops 262, 264.
[0204] The inverse clear input ({overscore (CLR)}) of the first and
second flip-flops 262, 264 are coupled to the microprocessor 244
via a buffer circuit 268. In the illustrated embodiment, the buffer
circuit 268 includes a first buffer 270, a first resistor 272 and a
capacitor 274. The electronic controller 118 may continuous supply
power to the motor 42 by turning on the first switch 246 and
continuously resetting the first and second flip-flops 262, 264
through the inverse clear inputs without turning off power to the
flip-flops 262, 264.
[0205] In one embodiment, the flip-flops 262, 264 are triggered by
logic level high ("HIGH") to logic level low ("LOW") transitions.
The buffer circuit 268 prevents erroneous signal transitions when
the input to the buffer circuit 268 is held HIGH by the
microprocessor 244.
[0206] With specific reference to FIG. 27, the motor control
circuit 242 includes the first FET 256 and the opto-coupler sensor
276. A flashback diode 278 is coupled across first and second motor
junctions 280A, 280B. The opto-coupler sensor 276 is coupled to the
second motor junction 280B. The transmitting diode of the opto
coupler sensor 276 is coupled to power (V+) and ground through
switch 256. In this arrangement the sensor 276 is only powered
during the time the motor 42 is running thus conserving battery
life. An output of the opto-coupler sensor 276 is coupled to the
third transistor 266 via a second buffer 282.
[0207] The gate of the first FET 256 is coupled to the
microprocessor 244. The drain of the first FET 256 is coupled to
the motor 42 and the source of the first FET 256 is connected to
the drain of the second FET 258.
[0208] As described above, the electronic controller 118 is adapted
to supply medication by energizing the motor 42. A desired flow
rate is achieved by energizing the motor 42 and waiting between
revolutions of the motor 42 for a calculated period of time. The
motor 42 is energized by turning on the first FET 256. In the
illustrated embodiment, the first FET 256 is turned on by the
microprocessor 244 by changing the state of the gate of the first
FET 256 from LOW to HIGH. If the second FET 258 is also on, then
power flows through the motor 42 and the first and second FETs 256,
258. When the motor 42 has made one (1) complete revolution, then
the output of the motor sensor 254 transitions from HIGH to LOW. In
the illustrated embodiment, this transition is the motor revolution
signal. The motor revolution signal is also transmitted to the
microprocessor 244 via the third FET 266. After receiving the motor
revolution signal the microprocessor 244 turns off the first FET
256 by changing the state of the gate of the first FET 256 from
HIGH to LOW.
[0209] During normal operation, the microprocessor 244 then turns
off power to the first and second flip-flops 262, 264. As described
above, based on the desired flow rate and the known quantity of
medication delivered per revolution of the motor 42, the
microprocessor 244 calculates a wait period between motor
revolutions. After the wait period (or right before the wait period
ends), the microprocessor 244 restores power to the first and
second flip-flops 262, 264. As discussed above, this resets the
first and second flip-flops 262, 264. Then the microprocessor 244
may again turn on the first FET 256 to energize the motor 42.
[0210] If a failure condition of the control system 240 exists,
such as a microprocessor 244 failure or other failure, and the
watchdog circuit 248 is not reset, then watchdog circuit 248 turns
off the second FET 258, thereby preventing power from being
supplied to the motor 42.
[0211] For example, if the microprocessor 244 fails while the first
FET 256 is on, then the motor 42 will continue to be energized. The
motor sensor 254 will generate motor revolution signals each time a
motor revolution is completed. However, the microprocessor 244 does
not or is unable to reset the watchdog circuit 248. Two successive
motor revolution signals received on the CLK input of the first
flip-flop 262 without the watchdog circuit 248 being reset will
flip the inverse output of the second flip-flop 264 (from HIGH to
LOW) and thus turn off the second FET 258.
[0212] Likewise, a failure of the first transistor 256 in the
closed state will continuously energize the motor 42. If the
microprocessor 244 does not reset the watchdog circuit 248, then
successive motor revolution signals received on the CLK input of
the first flip-flop 262 will flip the inverse output of the second
flip-flop 264 and thus turn off the second FET 258.
[0213] With the second FET 258 in the off state, power will not be
delivered to the motor 42.
[0214] Returning to FIG. 25, the control system 240 further
includes a key 284 which is connected to the electronic controller
118 only during initialization. In one embodiment, the key 284 is
part of the testing instrument 200 which is also used to test the
control system 240 after it has been assembled and the batteries 45
are installed. Upon initial power-up, the control system 240 will
only initialize if the key 284 is present. If the key 284 is not
present, then the control system 240 enters a disabled mode and
medication cannot be delivered.
[0215] In one embodiment, upon initial power-up the control system
240 sends a signal to the key 284. If present, the key 284 delivers
a return signal to the control system 240 indicating its presence.
The use of the key 284 ensures that the system 10 cannot be
improperly reset by removing and then re-inserting the batteries 45
or other power supply 43. If this occurs and the key 284 is not
present, the system 10 will not work.
[0216] The control system 240 includes a crystal 285 coupled to the
microprocessor 244. The crystal 285 controls the frequency at which
the microprocessor 244 operates in a conventional manner. However,
if the crystal 285 is operating improperly, the microprocessor 244
could begin to operate at either a higher frequency or a lower
frequency than intended. The microprocessor 244 also includes an
internal oscillator 286. In one embodiment, the control system 240
is adapted to compare a frequency of the crystal 285 with a
frequency associated with the internal oscillator 286. The
electronic controller 118 adapted to compare a difference between
the first and second frequencies and enter a disabled state if the
difference is greater than a predetermined threshold. Thus, if the
crystal 285 experiences a failure, the control system 10 will be
disabled.
[0217] The invention has been described in an illustrative manner,
and it is to be understood that the terminology which has been used
is intended to be in the nature of words of description rather than
of limitation.
[0218] Obviously, many modifications and variations of the present
invention are possible in light of the above teachings. It is,
therefore, to be understood that reference numerals are merely for
convenience and are not to be in any way limiting, the invention
may be practiced otherwise than as specifically described.
* * * * *