US20160058940A1 - Low-cost ambulatory medical pump - Google Patents

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.

Description

CROSS-REFERENCE TO RELATED APPLICATIONBackground of the Invention
• 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.
• 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.
• 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.
• 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.
• 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
• 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.
• 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.
• 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.
• 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.
• 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.
• The software-enforced service life and at least one cumulative pump operation value cannot be reset using the user interface.
• 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.
• The indication may be a visual display
• 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.
• The software-enforced service life and at least one cumulative pump operation value may be stored in nonvolatile memory.
• 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.
• 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.
• 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.
• 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.
• 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.
• The software-enforced service life may be less than 100 liters.
• 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.
• 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.
• 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.
• The software-enforced service life may be less than 1000 hours.
• 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.
• 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.
• 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.
• The program may further operate to allow entry through the user interface of a maximum flow rate for delivering medicament.
• 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.
• The user interface may consist solely of manually operated electronic switches for the purpose of receiving user input.
• 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.
• The computer program may further execute to require entry of a password sequence through the user interface for accepting or changing treatment protocol instructions.
• It is thus a feature of at least one embodiment of the invention to provide pump programming consistent with use in an unsupervised setting.
• The password sequence may make use of manually operated switches labeled for other purposes.
• 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.
• 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.
• 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.
• 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.
• 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.
• 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
• FIG. 1 is a simplified perspective view of the ambulatory pump assembly as provided to a patient;
• 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;
• FIG. 3 is a simplified block diagram of the electronics of the pump ofFIGS. 1 and 2 as controlled by internal electronic computer executing a stored program;
• FIG. 4 is a flowchart of the stored program ofFIG. 3 and the data structures used by that program;
• FIG. 5 is a first fragmentary cross-sectional view taken along5-5 ofFIG. 1 and a second perpendicular cross-section aligned therewith showing operation of the dual release elements ofFIG. 2; and
• 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
• Referring now toFIG. 1, anambulatory pump10 may operate in conjunction with amedicament bag12 communicating with anIV line14. Themedicament bag12 may be, for example, a flexible plastic bag of the type used to hold IV solutions, and theIV line14 provides a flexible tube allowing the flow of medicament from themedicament bag12 and apatient connector16 that may communicate with the patient through a needle or port or the like. TheIV line14 may include abubble filter17 for removing included air bubbles, limiting the need for air bubble sensing.
• Theambulatory pump10 provides a two-part housing having anupper electronics portion18 that may attach to alower clamp portion20 to receive theIV line14 therebetween along alongitudinal axis22 being generally the longest dimension of the housing of theambulatory pump10. As so received, theambulatory pump10 may pump liquid through theIV line14 by peristaltic action.
• In one embodiment, theambulatory pump10 is constructed to weigh less than a half pound and preferably less than 1.5″×2″×5″ so as to be easily carried by the patient, for example, in apouch24 also sized to receive themedicament bag12.
• Referring now toFIG. 2, the housing of the upper active portion may present on its front surface auser interface26 comprising, for example, a liquidcrystal type display28 for displaying symbols and alphanumeric characters under computer control. Theuser interface26 also provides multiplemembrane switch pushbuttons30 that may be activated by a user. Generally, the pushbuttons include a limited number of controls including, in one embodiment, run and stoppushbuttons30aand30b, respectively, that will stop and start operation of the pump as will be described below; arate pushbutton30callows setting of the maximum pumping rate of theambulatory pump10 in milliliters per hour by cycling through menu standard rates with each push (?). The pushbuttons also include a “volume to be infused”pushbutton30dallowing 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 aninformation pushbutton30 allowing the display of detailed information about the pump including remaining pump life (?).Pushbutton30fallows the unit to be turned on and off to conserve power. Abolus pushbutton30 allows short operation of the pump to deliver medicament in fixed patient controlled bolus quantities (?).
• A lower edge of theupper electronics portion18 provides for aclamp release slide32 as will be described below andsafety lock34 that must be simultaneously activated to remove thelower clamp portion20.
• Referring now toFIG. 3, theambulatory pump10 may include amicrocontroller36 being an electronic computer having a self-containednonvolatile memory38 holding anoperating program40 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.
• Themicrocontroller36 also provides various inputs and output lines communicating, for example, with thedisplay28 for providing display information thereon andvarious pushbuttons30 for receiving data related to their activation by user. In addition, themicrocontroller36 may provide control lines to thepump assembly42 having, for example, an internal DC electric motor (not shown) operating through a gear system to activateperistaltic plunger elements44 that may press against the containedIV line14 to push fluid therethrough. As is understood in the art, generally theperistaltic plunger elements44 extend in an undulating serpentine fashion to compress and release the tubing thereby moving fluid therethrough.
• Themicrocontroller36 may also communicate electrically with various sensors. For example, upstream anddownstream pressure sensors46 and48 which can be used to ensure proper operation of the pump by detecting abnormal pressures. Generally each of thepressure sensors46 and48 may provide a spring-loaded plunger that presses into the outer wall of theIV line14 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 theIV line14 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 theIV line14 and higher pressures of contained medicament will allow less deflection of the wall of theIV line14. The system may be calibrated for a particular material of theIV line14.
• All electrical components in theupper electronics portion18 maybe supplied with power by a containedstorage battery49 that may provide its power directly or through standard power processing circuits such as regulators and the like.
• Referring now toFIG. 4, during normal operation, a clinician will enter a total volume to be infused52 and an infusion rate54, as shown byprocess block50, by using theuser interface26 shown inFIG. 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 byprocess block56. The password may employ a predetermined sequence of pressing of the pushbuttons30 (for example, after the unit is turned on but before it is programmed) such as pressing therun pushbutton30aonce and thestop pushbutton30btwice. Such use of thepushbuttons30 may be without regard to the actual labels of the button as, in this example, “run” and “stop”.
• The total volume to be infused52 and the infusion rate54 are then used to compute atotal infusion time58 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 infused52 and theinfusion time58 represent received protocol instructions (either direct or indirect) from a clinician describing the intended operating limits of the fluid pump in a treatment protocol.
• At succeedingprocess block60, the total volume to be infused52 is compared against a preset software-enforcedvolume limit62 of thepump10 after the software-enforcedvolume limit62 is reduced by the cumulative pumpedvolume66. The cumulative pumpedvolume66 is set to zero when theambulatory pump10 is manufactured and then increases with operation of thepump assembly42. Similarly, thetotal infusion time58 is compared against a preset software-enforcedtime limit64 as reduced by the cumulativepump operation time68. The cumulative pump operation time is also set to zero when theambulatory pump10 is manufactured and then increases with operation of theambulatory pump10 determined from activation of the onpushbutton30fnot necessarily including activation of thepump assembly42. The net effect ofprocess block60 is to see if the intended treatment protocol can be performed before the service life of the pump has been exceeded.
• If either the use-adjusted, software-enforcedvolume limit62 or software-enforcedtime limit64 have been exceeded, as determined atdecision block70, theprogram40 proceeds to processblock72 and provides a warning that the treatment protocol may not be implemented as displayed on thedisplay28 ofFIG. 2. Theprogram40 then returns theprocess block50 without operation of thepump assembly42 and a new password and new values must be entered if operation is to be continued.Decision block70 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.
• If atdecision block70, the treatment protocol may be performed within the service limits of thepump10, then the program proceeds todecision block74 and may begin operation as indicated byprocess block76, when therun pushbuttons30ais pressed. The program loops until therun pushbutton30ais pressed or the unit is switched off.
• It will generally be understood that except through operation of theprogram40 executing on themicrocontroller36, thevalues66,68,62, and64 contained inmemory38 may not be changed and theprogram40 does not allow these values to be changed by the operator through theuser interface26. More generally, these values may not be changed by removing power from the ambulatory pump10 (e.g. removing battery49 shown inFIG. 3) and generally require disassembly of thepump10 to obtain direct access to the pin structure of themicrocontroller36 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 theambulatory pump10 ormicrocontroller36.
• The operation of the pump atprocess block76 will normally monitor thepressure sensors48 and46 to ensure there is no upstream or downstream occlusion of medicament flow. Any such obstruction will cause a ceasing of the operation of thepump assembly42 which may be reactivated after correction by the user. Duringprocess block76, pump flow-rate is controlled by controlling the speed of thepump assembly42 in open loop fashion according to the entered infusion rate54. During operation, the pump's76 accumulated time and pumping volume perprocess block77 are used to update cumulative pumpedvolume66 and cumulativepump operation time68.
• Periodically during operation of the pump at process block76 (or enforced on an interrupt basis),decision block78 may be polled to see if thestop pushbutton30bhas been pressed in which case thepump assembly42 stops and theprogram40 returns todecision block74.
• If thestop pushbutton30bofdecision block78 has not been pressed, theprogram40 proceeds todecision block80 to determine whether the total volume through theambulatory pump10 during this treatment protocol has reached the total volume to be infused52. If so, theprogram40 loops back toprocess block50, but if not the program returns to processblock76.
• It should be noted that the updating of the cumulative values perprocess block77 looks at actual rather than estimated hours and volumes pumped in contrast to the calculation ofprocess block60.
• Referring now toFIGS. 2 and 6, the upper surface of thelower clamp portion20 may provide for a shallow tray having upstanding peripheral longitudinally-opposedend walls90 and92, these walls separating the opposed upstanding peripheral longitudinally-extendingsidewalls94 and96. Theend walls90 may include notches receivingretention bushings98aand98 formed in theIV line14 to prevent longitudinal movement of theIV line14 with respect to thelower clamp portion20 along thelongitudinal axis22.
• Between thebushings98aand98b, the material of theIV line14 may be replaced with a silicon material that is softer and more conducive to peristaltic pumping and through-wall pressure sensing. The portion of theIV line14 within the tray of thelower clamp portion20 may be held byguides100 which form notches to align and retain theIV line14 with theperistaltic plunger elements44 and the downwardly extending operators of thepressure sensors46 and48 held in thebottom wall101 ofupper electronics portion18. Theguides100 may also provide for backstops holding theIV line14 against the pressure of the downwardly extending operators of thepressure sensors46 and48 and theperistaltic plunger elements44.
• TheIV line14 may pass through a springbias clamp element102 that automatically clamps theIV line14 when thelower clamp portion20 is separated from theupper electronics portion18.
• Rear sidewall96 includes upwardly extendingopen hinge collars104 spaced along its edge that may attached to and hinge abouthinge pin106 supported at a rear edge of thebottom wall101 of theupper electronics portion18, spaced below thebottom wall101 and generally parallel to thelongitudinal axis22.
• Front sidewall94 includes longitudinally-extendingtabs107 that may be engaged by correspondinghooks108 extending down from the front edge of thebottom wall101 of theupper electronics portion18 and activated byrelease slide32 as will be described to move generally along thelongitudinal axis22. When thelower clamp portion20 is attached by the interconnection ofopen hinge collars104 andhinge pin106 and pivoted upward toward the bottom101, thehooks108 may pass over and attach to thetabs107 to retain theupper electronics portion18 andlower clamp portion20 together with theIV line14 in proper alignment and clamp therebetween.
• By attaching thelower clamp portion20 to theupper electronics portion18 at multiple points across the narrower dimension of thelower clamp portion20, reduced flexure of thelower clamp portion20 may be obtained (as opposed to attachment atend walls92 and90) against the forces of theperistaltic plunger elements44 andpressure sensors46 and48 providing better alignment against minor tolerances and reduced flexure caused by the reduced unsupported span of the polymer material of thelower clamp portion20. This allows reduced material costs for thelower clamp portion20 and provides increased accuracy, for example, in the pressure sensing.
• Referring now toFIG. 5, the downwardly extendinghooks108 may be attached to acommon driver bar110 that is longitudinally spring biased by aspring112 into engagement with thetabs107 tending to hold thelower clamp portion20 against theupper electronics portion18. Thebar110 may communicate withrelease slide32 which may be pressed rightward against the biasingspring112 to allow release of thehooks108 from thetabs107. Leftward motion of thebar110 is only possible, however, whensafety lock34 is pressed inward against biasingspring112 in a direction perpendicular to thelongitudinal axis22 allowing a longitudinally-extendingopening114 in thesafety lock34 to align with thedriver bar110 permitting rightward movement of an extension of thecommon driver bar110 through the longitudinally-extendingopening14. Because the motion of theclamp release slide32 andsafety lock34 are in different directions and they are located in separated positions, accidental release of thelower clamp portion20 is greatly reduced.
• 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.)
• 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.
• 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.
• It will be appreciated that the look-ahead operation of theambulatory pump10 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.
• 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.

Claims (19)

We claim:

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 ofclaim 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 ofclaim 2 wherein the indication is a visual display.

4. The ambulatory infusion pump ofclaim 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 ofclaim 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 ofclaim 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 ofclaim 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 ofclaim 7 wherein the software-enforced service life is a predetermined value of less than 100 liters.

9. The ambulatory infusion pump ofclaim 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 ofclaim 9 wherein the software-enforced service life is less than a predetermined value of 1000 hours.

11. The ambulatory infusion pump ofclaim 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 ofclaim 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 ofclaim 1 wherein the user interface consists solely of manually operated electronic switches receiving user input.

14. The ambulatory infusion pump ofclaim 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 ofclaim 14 wherein the password sequence makes use of manually operated switches labeled for other purposes.

16. The ambulatory infusion pump ofclaim 1 wherein the housing further holds a battery for operating all electronics of the ambulatory infusion pump.

17. The ambulatory infusion pump ofclaim 1 wherein the pump has a total weight less than one pound.

18. The ambulatory infusion pump ofclaim 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 ofclaim 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.

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