U.S. patent application number 14/471102 was filed with the patent office on 2016-03-03 for low-cost ambulatory medical pump.
The applicant listed for this patent is Zyno Medical, LLC.. Invention is credited to Chaoyoung Lee, Mei Zhang.
Application Number | 20160058940 14/471102 |
Document ID | / |
Family ID | 55401298 |
Filed Date | 2016-03-03 |
United States Patent
Application |
20160058940 |
Kind Code |
A1 |
Zhang; Mei ; et al. |
March 3, 2016 |
LOW-COST AMBULATORY MEDICAL PUMP
Abstract
A low-cost medical pump for ambulatory use provides reduced life
components combined with a pump lockout enforcing a safe operating
limit and preventing reuse after that limit is exceeded. An
improved IV line clamp portion minimizes unsupported clamp
structure length and provides a dual lock system preventing
inadvertent clamp release.
Inventors: |
Zhang; Mei; (Sharon, MA)
; Lee; Chaoyoung; (Weston, MA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Zyno Medical, LLC. |
Natick |
MA |
US |
|
|
Family ID: |
55401298 |
Appl. No.: |
14/471102 |
Filed: |
August 28, 2014 |
Current U.S.
Class: |
604/67 |
Current CPC
Class: |
F04B 43/0072 20130101;
A61M 5/1413 20130101; A61M 2205/52 20130101; F04B 43/082 20130101;
A61M 39/284 20130101; A61M 2005/14292 20130101; A61M 5/14228
20130101; A61M 2205/502 20130101; A61M 2205/507 20130101; A61M
2205/505 20130101; A61M 5/14244 20130101; F04B 43/12 20130101 |
International
Class: |
A61M 5/142 20060101
A61M005/142; A61M 5/14 20060101 A61M005/14; A61M 39/28 20060101
A61M039/28 |
Claims
1. An ambulatory infusion pump comprising: a housing holding: (a)
an IV line support structure receiving an IV line set communicating
between an IV bag and a patient connection; (b) a fluid pump
communicating with the IV support structure to pump fluid through
the IV line when the IV line is held in the IV line support
structure; (c) a user interface for receiving programming commands
from a clinician; and (d) an electronic computer communicating with
the fluid pump and the user interface and executing a program
stored in non-transient medium to: (i) monitor operation of the
fluid pump to store at least one cumulative pump operation value
indicating a cumulative operation of the fluid pump from a time of
manufacture of the ambulatory infusion pump; (ii) receive treatment
protocol instructions through the user interface describing an
intended future operating limit of the fluid pump to pump fluid
through an IV line in a treatment protocol; (iii) determine whether
an amount of operation of the fluid pump necessary to implement
received treatment protocol instructions will exceed a
predetermined software-enforced service life of the ambulatory
fluid pump reduced by the at least one cumulative pump operation
value; and (iv) when the amount of operation of the fluid pump
necessary to implement the treatment protocol exceeds the
software-enforced service life of the ambulatory fluid pump reduced
by the at least one cumulative pump operation value; prevent
operation of the fluid pump.
2. The ambulatory infusion pump of claim 1 further providing an
indication to an individual providing the fluid pump operation
instructions through the user interface that the pump has rejected
the received treatment protocol instructions.
3. The ambulatory infusion pump of claim 2 wherein the indication
is a visual display.
4. The ambulatory infusion pump of claim 1 wherein the
software-enforced service life and the at least one cumulative pump
operation value cannot be reset using the user interface.
5. The ambulatory infusion pump of claim 4 wherein the
software-enforced service life and the at least one cumulative pump
operation value are stored in nonvolatile memory.
6. The ambulatory infusion pump of claim 5 wherein the
software-enforced service life and the at least one cumulative pump
operation value cannot be altered without disassembly of the pump
to access internal electronic components.
7. The ambulatory infusion pump of claim 1 wherein the
software-enforced service life and the at least one cumulative pump
operation value are units of volume of fluid pumped by the fluid
pump.
8. The ambulatory infusion pump of claim 7 wherein the
software-enforced service life is a predetermined value of less
than 100 liters.
9. The ambulatory infusion pump of claim 1 wherein the
software-enforced service life and the at least one cumulative pump
operation value are units of time of operation of the fluid
pump.
10. The ambulatory infusion pump of claim 9 wherein the
software-enforced service life is less than a predetermined value
of 1000 hours.
11. The ambulatory infusion pump of claim 9 wherein the
software-enforced service life and cumulative pump operation value
are a combination of volume of fluid pumped by the fluid pump and
time of operation of the fluid pump and wherein the program step
(iii) compares both a volume of fluid to be pumped by the fluid
pump needed to implement the treatment protocol against a volume of
fluid of the software-enforced service life, and a time of
operation of the fluid pump needed to implement the treatment
protocol against a time of operation of the of the
software-enforced service life, each reduced by respective
cumulative pump operation values; and (iv) when the amount of
operation of the fluid pump necessary to implement the treatment
protocol exceeds either of the reduced software-enforced service
lives of the ambulatory fluid pump, prevent operation of the fluid
pump.
12. The ambulatory infusion pump of claim 1 wherein the program
further operates to allow entry through the user interface of a
maximum flow rate for delivering medicament by control of the fluid
pump according to that value.
13. The ambulatory infusion pump of claim 1 wherein the user
interface consists solely of manually operated electronic switches
receiving user input.
14. The ambulatory infusion pump of claim 13 wherein the computer
program further executes to require entry of a password sequence
through the user interface for accepting or changing treatment
protocol instructions.
15. The ambulatory infusion pump of claim 14 wherein the password
sequence makes use of manually operated switches labeled for other
purposes.
16. The ambulatory infusion pump of claim 1 wherein the housing
further holds a battery for operating all electronics of the
ambulatory infusion pump.
17. The ambulatory infusion pump of claim 1 wherein the pump has a
total weight less than one pound.
18. The ambulatory infusion pump of claim 1 wherein the housing
provides a generally rectangular volume having an upper active
portion and a lower clamp portion attachable to the upper active
portion to hold the IV line therebetween extending along a
longitudinal axis and wherein the upper active portion and lower
clamp portion releasably attach to each other at multiple points
along opposed longitudinal interfacing edges.
19. The ambulatory infusion pump of claim 1 wherein the upper
active portion and lower clamp portion releasably attach along a
front longitudinal edge by inter-engaging sliding hooks and tabs
and wherein a front face of the housing exposes a slide operator
movable in a first direction to slide the hooks and a safety stop
movable against a spring in a second direction different from the
first direction to a state allowing sliding of the hooks; whereby
two distinct operations are required to release the lower clamp
portion.
Description
CROSS-REFERENCE TO RELATED APPLICATION
Background of the Invention
[0001] The present invention relates to compact infusion pumps for
ambulatory use and in particular to an infusion pump design to
reduce the costs of medical care delivery.
[0002] Medical pumps, such as infusion pumps, are known for
computer-controlled delivery of medication (henceforth medicaments)
to patients over a period of time. Recently, battery-powered
compact infusion pumps have become available that permit the
patient to remain active (ambulatory), for example, in a home
environment away from a clinic or hospital during the
treatment.
[0003] Typically the medicament is provided in a flexible bag that
may be connected to an IV line which in turn attaches to a needle
or port communicating with the patient. A nurse or other healthcare
professional ministering to the patient receives the medicament,
reviews the medicament description for correctness, and enters the
desired dose and rate into the pump. The IV line is then installed
in the portable pump and the assembly placed in a pack or other
carrying apparatus that may be retained on the patient. The
medicament may be delivered as the patient proceeds through normal
life activities until the full dose is complete. The patient may
then return the assembly to the nurse or health care professional
who may provide a new bag of medicament and IV line, and may
reprogram the pump for new treatment.
[0004] Pumps suitable for ambulatory use can have high total
operating costs driven in part by the cost of the pump itself which
must meet exacting medical standards while being compact,
lightweight, and ruggedized for portable use. The present inventors
have determined further that the recovery rate of ambulatory pumps
is historically low. Failure to recover the pump can occur when
pumps are used in end-of-life treatment, or are damaged or lost in
the field.
[0005] High operating costs associated with ambulatory pumps
necessarily limit the availability of the use of such medical
devices to some individuals even though the pump could greatly
improve the quality of care.
SUMMARY OF THE INVENTION
[0006] The present invention provides a cost-reduced ambulatory
pump intended to increase availability and acceptability of
ambulatory infusion. Lower cost is obtained by designing the pump
with a component's short operating life specification, recognizing
that the field operating life of such pumps is relatively short as
biased by low pump recovery rates. Safety is ensured by
incorporating absolute operating life limits into the pump that
prevent the pump from being used in excess of its design life. In
particular, maximum pump volume and maximum operating time may be
monitored and used to block further use of the pump if that use
would exceed safe operating limits. The pump also provides an
improved IV line clamp system reducing the material costs of a
significant mechanical component of the pump.
[0007] Specifically, the invention provides an ambulatory infusion
pump having a housing that holds an IV line support structure
receiving an IV line set and a fluid pump communicating with the IV
support structure to pump fluid through an IV line. The housing
also includes an electronic computer commuting with the fluid pump
and with a user interface for receiving programming commands from a
clinician. During operation, the electronic computer monitors
operation of the fluid pump to store at least one cumulative pump
operation value indicating a cumulative operation of the fluid pump
from a time of manufacture. The computer determines whether an
amount of operation of the fluid pump necessary to implement
received treatment protocol instructions will exceed the
software-enforced service life of the ambulatory fluid pump reduced
by at least one cumulative pump operation value, and if so,
prevents further operation of the fluid pump.
[0008] It is thus a feature of at least one object of the invention
to provide look-ahead lockout of the programming of the pump, and
when such programming is for a treatment protocol that would exceed
the design pump operating life value, such design pump operating
life is set to allow the safe use of durability components.
[0009] The computer may further provide an indication to an
individual providing the fluid pump operation instructions through
the user interface that the pump has rejected the received
treatment protocol instructions.
[0010] It is thus a feature of at least one embodiment of the
invention to clearly indicate the occurrence of the lockout, for
example, so that it is not interpreted as the need for service,
increasing pump-associated costs.
[0011] The software-enforced service life and at least one
cumulative pump operation value cannot be reset using the user
interface.
[0012] It is thus a feature of at least one embodiment of the
invention to prevent unauthorized recycling of unsafe pumps or
unsafe modification of the pump.
[0013] The indication may be a visual display
[0014] It is thus a feature of at least one embodiment of the
invention to make use of a pre-existing user program element to
provide an indication of pump lockout.
[0015] The software-enforced service life and at least one
cumulative pump operation value may be stored in nonvolatile
memory.
[0016] It is thus a feature of at least one embodiment of the
invention to reduce the chance of inadvertent or intentional
resetting of the service limits by removing power from the
pump.
[0017] The software-enforced service life and at least one
cumulative pump operation value are stored so that they cannot be
altered without disassembly of the pump to access internal
electronic components.
[0018] It is thus a feature of at least one embodiment of the
invention to provide hardware barriers to reuse of the pump beyond
its safe service life.
[0019] The software-enforced service life and at least one
cumulative pump operation value may be in units of volume of fluid
pumped by the fluid pump.
[0020] It is thus a feature of at least one embodiment of the
invention to provide a measure of pump operation which reveals wear
of the critical pump element.
[0021] The software-enforced service life may be less than 100
liters.
[0022] It is thus a feature of at least one embodiment of the
invention to limit pump operation to permit the use of lower-cost
pump elements subject to more rapid wear, for example, employing
lower-cost motors, simpler bearings and less expensive material
subject to wear.
[0023] Alternatively or in addition, the software-enforced service
life and at least one cumulative pump operation value may be units
of time of operation of the fluid pump.
[0024] It is thus a feature of at least one embodiment of the
invention to provide a measurement of pump field life that reveals
exposure of the pump to environmental contaminants and the aging of
pump components regardless of wear.
[0025] The software-enforced service life may be less than 1000
hours.
[0026] It is thus a feature of at least one embodiment of the
invention to limit pump operation to accommodate pump element
contamination and material aging.
[0027] The software-enforced service life and at least one
cumulative pump operation value may be a combination of volume of
fluid pumped by the fluid pump and time of operation of the fluid
pump, and the program may compare both a volume of fluid to be
pumped by the fluid pump against a volume of fluid of the
software-enforced service life and compare a time of operation of
the fluid pump against a time of operation of the ambulatory fluid
pump, each service life reduced by respective cumulative pump
operation values. When the amount of operation of the fluid pump
necessary to implement the treatment protocol exceeds either
adjusted software-enforced service lives, operation of the fluid
pump is prevented.
[0028] It is thus a feature of at least one embodiment of the
invention to combine two measures of service life together to
provide a more robust definition of the life of the pump.
[0029] The program may further operate to allow entry through the
user interface of a maximum flow rate for delivering
medicament.
[0030] It is thus a feature of at least one embodiment of the
invention to permit other safeguards to be determined by the
clinician programming the pump.
[0031] The user interface may consist solely of manually operated
electronic switches for the purpose of receiving user input.
[0032] It is thus a feature of at least one embodiment of the
invention to provide a cost-reduced control commensurate with the
desired low-cost design of the pump.
[0033] The computer program may further execute to require entry of
a password sequence through the user interface for accepting or
changing treatment protocol instructions.
[0034] It is thus a feature of at least one embodiment of the
invention to provide pump programming consistent with use in an
unsupervised setting.
[0035] The password sequence may make use of manually operated
switches labeled for other purposes.
[0036] It is thus a feature of at least one embodiment of the
invention to provide for password-secured settings without the need
for additional password input capabilities.
[0037] In some embodiments, the housing may provide a generally
rectangular volume having a an upper active portion and a lower
clamp portion attachable to the upper active portion to hold the IV
line therebetween extending along a longitudinal axis, and the
upper active portion and lower clamp portion may releasably attach
to each other at multiple points along opposed longitudinal
interfacing edges.
[0038] It is thus a feature of at least one embodiment of the
invention to provide a more robust IV line clamping system by
minimizing the unsupported span of the clamp portion.
[0039] The upper active portion and lower clamp portion may
releasably attach along a front longitudinal edge by inter-engaging
sliding hooks and tabs wherein a front face of the housing exposes
a slide operator movable in a first direction to slide the hooks,
and a safety stop movable against a spring in a second direction
different from the first direction to a state allowing sliding of
the hooks.
[0040] It is thus a feature of at least one embodiment of the
invention to better prevent accidental disengagement of the clamp
portion and IV line during ambulatory use.
[0041] These particular objects and advantages may apply to only
some embodiments falling within the claims and thus do not define
the scope of the invention.
BRIEF DESCRIPTION OF THE FIGURES
[0042] FIG. 1 is a simplified perspective view of the ambulatory
pump assembly as provided to a patient;
[0043] FIG. 2 is a front elevational view of the ambulatory pump
showing inter-assembly of an upper active portion and lower clamp
portion of the housing as separated by operation of dual release
elements and showing a user interface comprising a display and
manually operated buttons;
[0044] FIG. 3 is a simplified block diagram of the electronics of
the pump of FIGS. 1 and 2 as controlled by internal electronic
computer executing a stored program;
[0045] FIG. 4 is a flowchart of the stored program of FIG. 3 and
the data structures used by that program;
[0046] FIG. 5 is a first fragmentary cross-sectional view taken
along 5-5 of FIG. 1 and a second perpendicular cross-section
aligned therewith showing operation of the dual release elements of
FIG. 2; and
[0047] FIG. 6 is a perspective fragmentary view of the upper active
portion and lower clamp portion as released showing various
elements thereof.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0048] Referring now to FIG. 1, an ambulatory pump 10 may operate
in conjunction with a medicament bag 12 communicating with an IV
line 14. The medicament bag 12 may be, for example, a flexible
plastic bag of the type used to hold IV solutions, and the IV line
14 provides a flexible tube allowing the flow of medicament from
the medicament bag 12 and a patient connector 16 that may
communicate with the patient through a needle or port or the like.
The IV line 14 may include a bubble filter 17 for removing included
air bubbles, limiting the need for air bubble sensing.
[0049] The ambulatory pump 10 provides a two-part housing having an
upper electronics portion 18 that may attach to a lower clamp
portion 20 to receive the IV line 14 therebetween along a
longitudinal axis 22 being generally the longest dimension of the
housing of the ambulatory pump 10. As so received, the ambulatory
pump 10 may pump liquid through the IV line 14 by peristaltic
action.
[0050] In one embodiment, the ambulatory pump 10 is constructed to
weigh less than a half pound and preferably less than
1.5''.times.2''.times.5'' so as to be easily carried by the
patient, for example, in a pouch 24 also sized to receive the
medicament bag 12.
[0051] Referring now to FIG. 2, the housing of the upper active
portion may present on its front surface a user interface 26
comprising, for example, a liquid crystal type display 28 for
displaying symbols and alphanumeric characters under computer
control. The user interface 26 also provides multiple membrane
switch pushbuttons 30 that may be activated by a user. Generally,
the pushbuttons include a limited number of controls including, in
one embodiment, run and stop pushbuttons 30a and 30b, respectively,
that will stop and start operation of the pump as will be described
below; a rate pushbutton 30c allows setting of the maximum pumping
rate of the ambulatory pump 10 in milliliters per hour by cycling
through menu standard rates with each push (?). The pushbuttons
also include a "volume to be infused" pushbutton 30d allowing user
control of the maximum volume to be infused during a treatment
protocol, also by cycling through standard settings with each push,
as well as an information pushbutton 30 allowing the display of
detailed information about the pump including remaining pump life
(?). Pushbutton 30f allows the unit to be turned on and off to
conserve power. A bolus pushbutton 30 allows short operation of the
pump to deliver medicament in fixed patient controlled bolus
quantities (?).
[0052] A lower edge of the upper electronics portion 18 provides
for a clamp release slide 32 as will be described below and safety
lock 34 that must be simultaneously activated to remove the lower
clamp portion 20.
[0053] Referring now to FIG. 3, the ambulatory pump 10 may include
a microcontroller 36 being an electronic computer having a
self-contained nonvolatile memory 38 holding an operating program
40 and necessary storage variables as will be described below. The
nonvolatile memory may comprise, for example, flash memory and/or
read only memory, or other similar nonvolatile memory as context
requires, which may store data values to be retained even in the
absence of electrical power.
[0054] The microcontroller 36 also provides various inputs and
output lines communicating, for example, with the display 28 for
providing display information thereon and various pushbuttons 30
for receiving data related to their activation by user. In
addition, the microcontroller 36 may provide control lines to the
pump assembly 42 having, for example, an internal DC electric motor
(not shown) operating through a gear system to activate peristaltic
plunger elements 44 that may press against the contained IV line 14
to push fluid therethrough. As is understood in the art, generally
the peristaltic plunger elements 44 extend in an undulating
serpentine fashion to compress and release the tubing thereby
moving fluid therethrough.
[0055] The microcontroller 36 may also communicate electrically
with various sensors. For example, upstream and downstream pressure
sensors 46 and 48 which can be used to ensure proper operation of
the pump by detecting abnormal pressures. Generally each of the
pressure sensors 46 and 48 may provide a spring-loaded plunger that
presses into the outer wall of the IV line 14 to sense pressure.
This through-wall measurement avoids the need for separate
connections to the fluid-contacting pressure sensor and the
problems of sterilization of a fluid-contacting pressure sensor. In
such a through-tubing sensing system, the spring-loaded plunger
deforms a portion of a wall of the IV line 14 as held against a
backstop. Under a known spring biasing force, the amount of
deflection of the wall may be measured to deduce internal pressure.
Generally, lower pressures of the contained medicament will allow
greater deflection of the wall of the IV line 14 and higher
pressures of contained medicament will allow less deflection of the
wall of the IV line 14. The system may be calibrated for a
particular material of the IV line 14.
[0056] All electrical components in the upper electronics portion
18 maybe supplied with power by a contained storage battery 49 that
may provide its power directly or through standard power processing
circuits such as regulators and the like.
[0057] Referring now to FIG. 4, during normal operation, a
clinician will enter a total volume to be infused 52 and an
infusion rate 54, as shown by process block 50, by using the user
interface 26 shown in FIG. 2. In order to prevent tampering or
inadvertent change in these values, their entry is accomplished
through a password which must be entered first, indicated by
process block 56. The password may employ a predetermined sequence
of pressing of the pushbuttons 30 (for example, after the unit is
turned on but before it is programmed) such as pressing the run
pushbutton 30a once and the stop pushbutton 30b twice. Such use of
the pushbuttons 30 may be without regard to the actual labels of
the button as, in this example, "run" and "stop".
[0058] The total volume to be infused 52 and the infusion rate 54
are then used to compute a total infusion time 58 that may, but
need not be, a continuous time period but which may also be a
cumulative time necessary for the infusion, contemplating that the
infusion may be started and stopped by the patient. The total
volume to be infused 52 and the infusion time 58 represent received
protocol instructions (either direct or indirect) from a clinician
describing the intended operating limits of the fluid pump in a
treatment protocol.
[0059] At succeeding process block 60, the total volume to be
infused 52 is compared against a preset software-enforced volume
limit 62 of the pump 10 after the software-enforced volume limit 62
is reduced by the cumulative pumped volume 66. The cumulative
pumped volume 66 is set to zero when the ambulatory pump 10 is
manufactured and then increases with operation of the pump assembly
42. Similarly, the total infusion time 58 is compared against a
preset software-enforced time limit 64 as reduced by the cumulative
pump operation time 68. The cumulative pump operation time is also
set to zero when the ambulatory pump 10 is manufactured and then
increases with operation of the ambulatory pump 10 determined from
activation of the on pushbutton 30f not necessarily including
activation of the pump assembly 42. The net effect of process block
60 is to see if the intended treatment protocol can be performed
before the service life of the pump has been exceeded.
[0060] If either the use-adjusted, software-enforced volume limit
62 or software-enforced time limit 64 have been exceeded, as
determined at decision block 70, the program 40 proceeds to process
block 72 and provides a warning that the treatment protocol may not
be implemented as displayed on the display 28 of FIG. 2. The
program 40 then returns the process block 50 without operation of
the pump assembly 42 and a new password and new values must be
entered if operation is to be continued. Decision block 70 may also
check for adequate remaining battery energy for the protocol using
an internal time-to-ampere-hour conversions based on the current
drain of the ambulatory pump and comparing that against the
estimated total ampere-hours of the battery.
[0061] If at decision block 70, the treatment protocol may be
performed within the service limits of the pump 10, then the
program proceeds to decision block 74 and may begin operation as
indicated by process block 76, when the run pushbuttons 30a is
pressed. The program loops until the run pushbutton 30a is pressed
or the unit is switched off.
[0062] It will generally be understood that except through
operation of the program 40 executing on the microcontroller 36,
the values 66, 68, 62, and 64 contained in memory 38 may not be
changed and the program 40 does not allow these values to be
changed by the operator through the user interface 26. More
generally, these values may not be changed by removing power from
the ambulatory pump 10 (e.g. removing battery 49 shown in FIG. 3)
and generally require disassembly of the pump 10 to obtain direct
access to the pin structure of the microcontroller 36 and
specialized equipment to access the memory directly if that is even
possible. It is contemplated that these values may be stored in a
way that cannot be changed without destruction of the ambulatory
pump 10 or microcontroller 36.
[0063] The operation of the pump at process block 76 will normally
monitor the pressure sensors 48 and 46 to ensure there is no
upstream or downstream occlusion of medicament flow. Any such
obstruction will cause a ceasing of the operation of the pump
assembly 42 which may be reactivated after correction by the user.
During process block 76, pump flow-rate is controlled by
controlling the speed of the pump assembly 42 in open loop fashion
according to the entered infusion rate 54. During operation, the
pump's 76 accumulated time and pumping volume per process block 77
are used to update cumulative pumped volume 66 and cumulative pump
operation time 68.
[0064] Periodically during operation of the pump at process block
76 (or enforced on an interrupt basis), decision block 78 may be
polled to see if the stop pushbutton 30b has been pressed in which
case the pump assembly 42 stops and the program 40 returns to
decision block 74.
[0065] If the stop pushbutton 30b of decision block 78 has not been
pressed, the program 40 proceeds to decision block 80 to determine
whether the total volume through the ambulatory pump 10 during this
treatment protocol has reached the total volume to be infused 52.
If so, the program 40 loops back to process block 50, but if not
the program returns to process block 76.
[0066] It should be noted that the updating of the cumulative
values per process block 77 looks at actual rather than estimated
hours and volumes pumped in contrast to the calculation of process
block 60.
[0067] Referring now to FIGS. 2 and 6, the upper surface of the
lower clamp portion 20 may provide for a shallow tray having
upstanding peripheral longitudinally-opposed end walls 90 and 92,
these walls separating the opposed upstanding peripheral
longitudinally-extending sidewalls 94 and 96. The end walls 90 may
include notches receiving retention bushings 98a and 98 formed in
the IV line 14 to prevent longitudinal movement of the IV line 14
with respect to the lower clamp portion 20 along the longitudinal
axis 22.
[0068] Between the bushings 98a and 98b, the material of the IV
line 14 may be replaced with a silicon material that is softer and
more conducive to peristaltic pumping and through-wall pressure
sensing. The portion of the IV line 14 within the tray of the lower
clamp portion 20 may be held by guides 100 which form notches to
align and retain the IV line 14 with the peristaltic plunger
elements 44 and the downwardly extending operators of the pressure
sensors 46 and 48 held in the bottom wall 101 of upper electronics
portion 18. The guides 100 may also provide for backstops holding
the IV line 14 against the pressure of the downwardly extending
operators of the pressure sensors 46 and 48 and the peristaltic
plunger elements 44.
[0069] The IV line 14 may pass through a spring bias clamp element
102 that automatically clamps the IV line 14 when the lower clamp
portion 20 is separated from the upper electronics portion 18.
[0070] Rear sidewall 96 includes upwardly extending open hinge
collars 104 spaced along its edge that may attached to and hinge
about hinge pin 106 supported at a rear edge of the bottom wall 101
of the upper electronics portion 18, spaced below the bottom wall
101 and generally parallel to the longitudinal axis 22.
[0071] Front sidewall 94 includes longitudinally-extending tabs 107
that may be engaged by corresponding hooks 108 extending down from
the front edge of the bottom wall 101 of the upper electronics
portion 18 and activated by release slide 32 as will be described
to move generally along the longitudinal axis 22. When the lower
clamp portion 20 is attached by the interconnection of open hinge
collars 104 and hinge pin 106 and pivoted upward toward the bottom
101, the hooks 108 may pass over and attach to the tabs 107 to
retain the upper electronics portion 18 and lower clamp portion 20
together with the IV line 14 in proper alignment and clamp
therebetween.
[0072] By attaching the lower clamp portion 20 to the upper
electronics portion 18 at multiple points across the narrower
dimension of the lower clamp portion 20, reduced flexure of the
lower clamp portion 20 may be obtained (as opposed to attachment at
end walls 92 and 90) against the forces of the peristaltic plunger
elements 44 and pressure sensors 46 and 48 providing better
alignment against minor tolerances and reduced flexure caused by
the reduced unsupported span of the polymer material of the lower
clamp portion 20. This allows reduced material costs for the lower
clamp portion 20 and provides increased accuracy, for example, in
the pressure sensing.
[0073] Referring now to FIG. 5, the downwardly extending hooks 108
may be attached to a common driver bar 110 that is longitudinally
spring biased by a spring 112 into engagement with the tabs 107
tending to hold the lower clamp portion 20 against the upper
electronics portion 18. The bar 110 may communicate with release
slide 32 which may be pressed rightward against the biasing spring
112 to allow release of the hooks 108 from the tabs 107. Leftward
motion of the bar 110 is only possible, however, when safety lock
34 is pressed inward against biasing spring 112 in a direction
perpendicular to the longitudinal axis 22 allowing a
longitudinally-extending opening 114 in the safety lock 34 to align
with the driver bar 110 permitting rightward movement of an
extension of the common driver bar 110 through the
longitudinally-extending opening 14. Because the motion of the
clamp release slide 32 and safety lock 34 are in different
directions and they are located in separated positions, accidental
release of the lower clamp portion 20 is greatly reduced.
[0074] Certain terminology is used herein for purposes of reference
only, and thus is not intended to be limiting. For example, terms
such as "upper", "lower", "above", and "below" refer to directions
in the drawings to which reference is made. Terms such as "front",
"back", "rear", "bottom" and "side", describe the orientation of
portions of the component within a consistent but arbitrary frame
of reference which is made clear by reference to the text and the
associated drawings describing the component under discussion. Such
terminology may include the words specifically mentioned above,
derivatives thereof, and words of similar import. Similarly, the
terms "first", "second" and other such numerical terms referring to
structures do not imply a sequence or order unless clearly
indicated by the context. Indication is used herein to mean any
type of sense to indication including an audio alarm, visual
display or other computer-controlled activation (motor buzz,
etc.)
[0075] When introducing elements or features of the present
disclosure and the exemplary embodiments, the articles "a", "an",
"the" and "said" are intended to mean that there are one or more of
such elements or features. The terms "comprising", "including" and
"having" are intended to be inclusive and mean that there may be
additional elements or features other than those specifically
noted. It is further to be understood that the method steps,
processes, and operations described herein are not to be construed
as necessarily requiring their performance in the particular order
discussed or illustrated, unless specifically identified as an
order of performance. It is also to be understood that additional
or alternative steps may be employed.
[0076] References to "a microprocessor" and "a processor" or "the
microprocessor" and "the processor," can be understood to include
one or more microprocessors or other types of computers, gate
arrays or the like that can execute programs and communicate with
each other. Furthermore, references to memory, unless otherwise
specified, can include one or more processor-readable and
accessible memory elements and/or components that can be internal
to the processor-controlled device, external to the
processor-controlled device, and can be accessed via a wired or
wireless network. The term manual pushbuttons means buttons that
may be operated by finger touch or the like including touchscreen
and passive switch and mechanical switch.
[0077] It will be appreciated that the look-ahead operation of the
ambulatory pump 10 described herein is consistent both with
anticipatory locking of the pump so that the pump does not exceed
the service values, as well as setting the service values to a
value below the actual longest desired service value by amount of
the typical treatment protocol and allowing the treatment protocol
to exceed the service value once, and then locking out pump. In
this latter case, the pump lockout anticipates that the next
treatment protocol would exceed the remaining operating time or
volume (which is a negative value) and need not actually accept a
new protocol.
[0078] It is specifically intended that the present invention not
be limited to the embodiments and illustrations contained herein
and the claims should be understood to include modified forms of
those embodiments including portions of the embodiments and
combinations of elements of different embodiments as come within
the scope of the following claims. All of the publications
described herein, including patents and non-patent publications,
are hereby incorporated herein by reference in their
entireties.
* * * * *