Infusion pump system including temperature compensation for infusion rate adjustment

Abstract

To provide an infusion pump system including temperature compensation for infusion rate adjustment.SOLUTION: An infusion pump system is disclosed. The system includes a syringe having a plunger within a syringe barrel, the syringe having as an exit end at least one temperature determination device adjacent to the syringe, at least one device to determine the distance the plunger has traveled relatively to the syringe barrel, and a pump processor in communication with the at least one temperature determination device and the at least one optical sensor. When the controller determines a change in temperature and a corresponding plunger movement, the controller increases or decreases a preprogrammed basal rate of the infusion pump by a predetermined amount for a predetermined time.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] (CROSS REFERENCE TO RELATED APPLICATIONS) This application is a non-provisional patent application that claims priority to U.S. Provisional Patent Application No. 61 / 297,387, filed Jan. 22, 2010, entitled "Infusion Pump Apparatus, Method and System," Attorney Docket No. H83, which is incorporated herein by reference in its entirety.

[0002] (Technical field) The present disclosure relates to medical devices, and more particularly, to infusion pump apparatus, methods and systems. [Background technology]

[0003] (Background information) Many potentially valuable drugs or compounds, including biologics, are not orally effective due to poor absorption, hepatic metabolism, or other pharmacokinetic factors. Furthermore, some therapeutic compounds can be absorbed orally, but may need to be administered frequently, making it difficult for patients to maintain the desired schedule. In such cases, parenteral delivery is often employed or can be employed.

[0004] Effective parenteral routes of drug delivery and other fluids and compounds, such as subcutaneous injection, intramuscular injection, and intravenous (IV) administration, involve puncturing the skin with a needle or stylet. Insulin is an example of a therapeutic fluid that is self-injected by millions of diabetic patients. Users of parenterally delivered drugs could benefit from a wearable device that would automatically deliver the needed drug / compound over a period of time.

[0005] To this end, efforts have been made to design portable and wearable devices for the controlled release of therapeutic agents. Such devices are known to have a reservoir, such as a cartridge, syringe, or bag, and are electronically controlled. These devices suffer from several drawbacks, including failure rates. Reducing the size, weight, and cost of these devices is also a continuing challenge. Furthermore, these devices are often applied to the skin, presenting the challenge of frequent repositioning for application. Summary of the Invention [Means for solving the problem]

[0006] According to one aspect of the invention, an infusion pump system is disclosed that includes a syringe having a plunger within the syringe barrel, the syringe having an outlet end, at least one temperature determining device adjacent the syringe, at least one device for determining a distance the plunger has traveled relative to the syringe barrel, a pump processor in communication with the at least one temperature determining device and at least one optical sensor, and when the controller determines a temperature change and corresponding plunger movement, the controller increases or decreases a preprogrammed basal rate of the infusion pump by a predetermined amount for a predetermined time.

[0007] Some embodiments may include one or more of the following: When the pump processor determines an upward temperature change and corresponding plunger movement away from the syringe outlet, the pump processor increases the preprogrammed basal rate of the infusion pump by a predetermined amount for a predetermined time. When the pump processor determines a downward temperature change and corresponding plunger movement toward the syringe outlet, the pump processor decreases the preprogrammed basal rate of the infusion pump by a predetermined amount for a predetermined time. The at least one temperature determining device is a thermistor. The at least one device for determining the distance the plunger has moved relative to the syringe barrel is an optical sensor.

[0008] In accordance with one aspect of the present invention, an infusion pump system is disclosed that includes a syringe having an outlet end and a plunger movable within the syringe, at least one temperature determining device, at least one device for determining the effect of temperature changes on movement of the plunger, and a pump processor for compensating for movement of the plunger based on the temperature changes.

[0009] Some embodiments may include one or more of the following: The pump processor commands the plunger to move a predetermined distance away from the syringe outlet and compensates for the movement of the plunger based on temperature changes. The pump processor reduces the preprogrammed basal rate by a predetermined amount for a predetermined time based on the movement of the plunger based on the temperature change. The at least one temperature determining device is located adjacent to the syringe. The at least one temperature determining device is a thermistor. The at least one device for determining the effect of temperature changes on the movement of the plunger is an optical sensor.

[0010] In accordance with one aspect of the present invention, an infusion pump system is disclosed that includes a syringe having an outlet end and a plunger movable within the syringe, at least one temperature determining device, at least one device for determining the effect of temperature changes on movement of the plunger, and a pump processor in communication with the at least one temperature determining device and the at least one device for determining the effect of temperature changes on movement of the plunger.

[0011] Some embodiments may include one or more of the following: The at least one device for determining the effect of temperature changes on the movement of the plunger is a flow sensor located downstream from the syringe outlet. The at least one device for determining the effect of temperature changes on the movement of the plunger is an occlusion device located downstream from the syringe outlet, the occlusion device occluding the flow path, the occlusion device being controlled by the pump processor. The at least one device for determining the effect of temperature changes on the movement of the plunger is at least one binary valve located downstream from the syringe outlet, the at least one binary valve occluding the flow path, the at least one binary valve being controlled by the pump processor. The at least one device for determining the effect of temperature changes on the movement of the plunger is a strain beam located in a force relationship with the plunger. The at least one device for determining the effect of temperature changes on the movement of the plunger is at least one potentiometer. The plunger further comprises a volume of material that undergoes a phase change during a temperature change event. The material is a wax that undergoes a phase change to move the plunger forward a predetermined distance, the resulting change compensating for volume changes in the syringe due to temperature changes.

[0012] According to one aspect of the invention, an infusion pump system is disclosed that includes a syringe having an outlet end and a plunger movable within the syringe, an occluder located downstream from the syringe outlet, at least one temperature determining device, and a pump processor in communication with the occluder and the at least one temperature determining device, the pump processor actuating the occluder based on a temperature signal from the at least one temperature determining device.

[0013] Some embodiments may include one or more of the following: the pump controller activates the occluder when the at least one temperature determining device signal indicates a temperature change above a predetermined threshold; the pump controller activates the occluder during pump delivery.

[0014] According to one aspect of the invention, a method for delivery of fluid by an infusion pump is disclosed, the method including the steps of determining a distance a plunger should travel to deliver a target volume, determining a volume of fluid to be delivered as temperature changes, determining a target plunger position, and adjusting the target plunger position based on the actual travel of the temperature change.

[0015] According to one aspect of the present invention, a method for delivery of a fluid by an infusion pump is disclosed, the method including the steps of determining a temperature change, determining that a rate of change exceeds a threshold, and adjusting a basal rate.

[0016] According to one aspect of the present invention, a system, method, and apparatus for temperature compensation in an infusion pump and an infusion pump having temperature compensation are disclosed. The system includes at least one temperature sensor in communication with at least one processor. The processor may determine a target plunger position based on at least a communication from the temperature sensor and may modify the target plunger position based on the sensed temperature.

[0017] Some embodiments may include one or more of an occluder and / or a binary outlet valve, at least one optical sensor, and at least one flow sensor.

[0018] According to one aspect of the invention, a system for temperature compensation in an infusion pump is disclosed. The system includes characterization of the infusion pump at various temperatures, including characterization of the volume of fluid pumped based on demand or temperature changes. Also includes at least one temperature sensor that collects data indicative of temperature inside or outside the infusion pump and communicates the data to a processor. The processor may compare the data to the characterization and determine to adjust a target plunger position based on the temperature. Some embodiments may include an occluder and / or a binary outlet valve.

[0019] In accordance with one aspect of the present invention, an apparatus for insulating an infusion pump is disclosed. The apparatus includes a housing of a predetermined size for receiving the infusion pump, the housing having at least one insulating layer. The housing includes an opening of a predetermined size for receiving tubing.

[0020] Some embodiments may include one or more of a strap, the strap is adjustable, the strap includes a buckle, the device includes an insulating layer constructed from a material that provides a cooling effect on the housing when moistened and refrigerated or frozen.

[0021] According to one aspect of the invention, an infusion pump having a heater includes a heating device and at least one temperature sensor such that the temperature is communicated to a processor which controls the heating device and activates the heating device for a period of time sufficient to maintain the temperature of the infusion pump at a predetermined temperature.

[0022] According to one aspect of the invention, a temperature label for a vial of fluid is disclosed. The temperature label visually indicates the temperature of the vial. Some embodiments of this aspect of the invention may include that the temperature label is non-reversible.

[0023] These aspects of the invention are not meant to be exclusive, and other features, aspects, and advantages of the present invention will become readily apparent to those of ordinary skill in the art when read in conjunction with the appended claims and accompanying drawings. For example, the present invention provides the following: (Item 1) 1. An infusion pump system, comprising: a syringe having a plunger movable within a syringe barrel, the syringe having an outlet end; at least one temperature determining device adjacent to the syringe; at least one device for determining the distance the plunger has traveled relative to the syringe barrel; a pump processor in communication with the at least one temperature determining device and the at least one optical sensor; wherein when a controller determines a change in temperature and corresponding plunger movement, the controller increases or decreases a preprogrammed basal rate of the infusion pump by a predetermined amount for a predetermined time. (Item 2) 2. The system of claim 1, further comprising: when the pump processor determines an upward change in temperature and corresponding plunger movement away from the syringe outlet, the pump processor increases the preprogrammed basal rate of the infusion pump by a predetermined amount for a predetermined time. (Item 3) 2. The system of claim 1, further comprising: when the pump processor determines a downward change in temperature and corresponding plunger movement toward the syringe outlet, the pump processor reduces the preprogrammed basal rate of the infusion pump by a predetermined amount for a predetermined time. (Item 4) 2. The system of claim 1, further comprising: the at least one temperature determining device being a thermistor. (Item 5) 2. The system of claim 1, further comprising: at least one device for determining a distance the plunger has moved relative to the syringe barrel is an optical sensor. (Item 6) 1. An infusion pump system, comprising: a syringe having an outlet end and a plunger movable within the syringe; at least one temperature determining device; at least one device for determining the effect of temperature changes on the movement of the plunger; a pump processor for compensating for the movement of the plunger based on temperature changes; Including, the system. (Item 7) 7. The system of claim 6, wherein the pump processor compensates for movement of the plunger based on temperature changes by commanding the plunger to move a predetermined distance away from the syringe outlet. (Item 8) 7. The system of claim 6, wherein the pump processor decreases the preprogrammed basal rate by a predetermined amount for a predetermined time based on movement of the plunger based on temperature change. (Item 9) 7. The system of claim 6, wherein the at least one temperature determination device is located adjacent to the syringe. (Item 10) 7. The system of claim 6, wherein the at least one temperature determining device is a thermistor. (Item 11) 7. The system of claim 6, wherein at least one device for determining the effect of temperature changes on the movement of the plunger is an optical sensor. (Item 12) 1. An infusion pump system, comprising: a syringe having an outlet end and a plunger movable within the syringe; at least one temperature determining device; at least one device for determining the effect of temperature changes on the movement of the plunger; a pump processor in communication with the at least one temperature determining device and with at least one device for determining an effect of temperature changes on the movement of the plunger; Including, the system. (Item 13) 2. The system of claim 1, wherein at least one device for detecting the effect of temperature changes on the movement of the plunger is a flow sensor located downstream from the syringe outlet. (Item 14) 2. The system of claim 1, wherein the at least one device for detecting the effect of temperature changes on the movement of the plunger is an occlusion device located downstream from the syringe outlet, the occlusion device occluding the flow path, and the occlusion device is controlled by the pump processor. (Item 15) 2. The system of claim 1, wherein the at least one device for detecting the effect of temperature changes on the movement of the plunger is at least one binary valve located downstream from the syringe outlet, the at least one binary valve occluding a flow path, and the at least one binary valve is controlled by the pump processor. (Item 16) 2. The system of claim 1, wherein the at least one device for determining the effect of temperature change on the movement of the plunger is a strain beam positioned in a force relationship with the plunger. (Item 17) 2. The system of claim 1, wherein the at least one device for determining the effect of temperature change on the movement of the plunger is at least one potentiometer. (Item 18) Item 13. The system of item 1, wherein the plunger further comprises a volume of material that undergoes a phase change during a temperature change event. (Item 19) Item 19. The system of item 18, wherein the material is a wax that undergoes a phase change to move the plunger forward a predetermined distance, whereby the resulting change compensates for volume changes in the syringe due to temperature changes. (Item 20) 1. An infusion pump system, comprising: a syringe having an outlet end and a plunger movable within the syringe; an occluder located downstream from the syringe outlet; at least one temperature determining device; a pump processor in communication with the occluder and the at least one temperature determining device, the pump processor activating the occluder based on a temperature signal from the at least one temperature determining device; Including, the system. (Item 21) 21. The system of claim 20, wherein the pump controller activates the occluder when the signal of the at least one temperature determining device indicates a temperature change exceeding a predetermined threshold. (Item 22) 21. The system of claim 20, wherein a pump controller activates the occluder during pump delivery. (Item 23) 1. A method for delivery of a fluid by an infusion pump, the method comprising: determining a distance that the plunger should travel to deliver a target volume; Determining a volume of fluid delivered as the temperature changes; Determining a target plunger position; adjusting the target plunger position based on actual movement with respect to temperature changes; A method comprising: (Item 24) 1. A method for delivery of a fluid by an infusion pump, the method comprising: Determining a temperature change; determining that the rate of change exceeds a threshold; Adjusting the basal rate A method comprising: (Item 25) 1. A system for temperature compensation of an infusion pump, the system comprising: At least one temperature sensor; at least one processor in communication with the temperature sensor; wherein the processor determines a target plunger position and modifies the target plunger position based on a sensed temperature based at least on communications from the temperature sensor.

[0024] These and other features and advantages of the present invention will be better understood from the following detailed description taken in conjunction with the following drawings. [Brief description of the drawings]

[0025] [Figure 1-1] 1A-1B are front and back isometric views of one embodiment of an infusion pump. [Figure 1-2] 1C-1E are side and front views of the infusion pump assembly of FIG 1. FIG 1F is a front isometric view of the infusion pump assembly of FIG 1. [Diagram 3] FIG. 3 is an illustration of one embodiment of a remote control assembly. [Figure 4] FIG. 4 is a diagram of the infusion pump assembly of FIG. [Figure 10] 10A-10E depict several hook and loop fastener configurations, according to some embodiments. [Figure 11] FIG. 11 is an illustration of one embodiment of a holder. [Figure 12] FIG. 12 is an illustration of one embodiment of a user wearing the holder. [Figure 13] FIG. 13 is an illustration of one embodiment of the back side of the holder. [Figure 14] FIG. 14 is an illustration of one embodiment of a vial with a thermometer / label. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] (definition) As used in this description and the appended claims, the following terms shall have the meanings indicated, unless the context otherwise requires.

[0027] "Device" is intended to mean a medical device, including but not limited to an infusion pump and / or a controller, i.e., a device for wireless control of another medical device. In some embodiments, the word "device" is used interchangeably with "pump," "infusion pump," and / or "controller," and / or "companion," and / or "remote controller device," and / or "remote controller assembly."

[0028] "Companion" shall mean a device for wireless control of another medical device. In an exemplary embodiment, the companion may also include a glucose meter / strip reader.

[0029] An "input" of a device may include any mechanism by which a user of the device or other operator / caregiver may control the functions of the device. User inputs may include mechanical arrangements (e.g., switches, push buttons, jog wheel(s)), electrical arrangements (e.g., sliders, touch screens), wireless interfaces for communication with remote controllers (e.g., RF, infrared), acoustic interfaces (e.g., with voice recognition), computer network interfaces (e.g., USB ports), and other types of interfaces.

[0030] A "button" in the context of an input such as what is referred to as a "bolus button" described below may be any type of user input capable of performing a desired function, and is not limited to a push button, slider, switch, touch screen, or jog wheel.

[0031] An "alarm" includes any mechanism by which an alert to a user or third party may be generated. An alarm may include an audible alarm (e.g., speaker, buzzer, voice generator), a visual alarm (e.g., LED, LCD screen), a tactile alarm (e.g., vibrating element), a wireless signal (e.g., wireless transmission to a remote controller or caretaker), or other mechanism. An alarm may be generated using multiple mechanisms simultaneously, in parallel, or sequentially, including overlapping mechanisms (e.g., two different audible alarms) or complementary mechanisms (e.g., an audible alarm, a tactile alarm, and a wireless alarm).

[0032] "Fluid" is intended to mean a substance, e.g., a liquid, that can flow through a flow line.

[0033] "User" includes a person or animal that receives fluid from a fluid delivery device, whether as part of a medical treatment or not, or a caregiver or third party involved in programming the device to inject fluid into another or otherwise interacting with the device.

[0034] "Cannula" is intended to mean a disposable device that can inject fluid into a user. As used herein, cannula may refer to a typical cannula or a needle.

[0035] "Disposable" refers to a part, device, portion, or other thing that is intended to be used for a fixed period of time and then discarded and replaced.

[0036] "Reusable" refers to a part that is intended to have an unlimited period of use.

[0037] "Acoustic volume measurement" shall mean the quantitative measurement of relevant volumes using acoustic techniques such as those described in U.S. Pat. Nos. 5,349,852 and 5,641,892, which are incorporated by reference herein in their entireties, as well as other techniques.

[0038] A "temperature sensor" includes any temperature determining device / mechanism for measuring temperature and communicating temperature information to the controller and / or pump processor. The devices described herein may include one or more temperature sensors for measuring, including but not limited to, a user's skin temperature, AVS temperature, ambient temperature, internal pump temperature, plunger temperature, driveline temperature, and fluid temperature.

[0039] An exemplary application of the embodiments of the devices, methods, and systems described herein is for the delivery of insulin to people living with diabetes, although other applications include the delivery of any fluid, as previously described. Fluids include painkillers for people with pain, chemotherapy for cancer patients, and enzymes for patients with metabolic diseases. Various therapeutic fluids may include small molecules, natural products, peptides, proteins, nucleic acids, carbohydrates, nanoparticle suspensions, and related pharma- ceutically acceptable carrier molecules. The therapeutically active molecules may be modified to improve stability within the device (e.g., by pegylation of peptides or proteins). Although specific embodiments herein describe drug delivery applications, the embodiments may be used for other applications, including lab-on-a-chip applications and liquid dispensing of reagents for high-throughput analytical measurements such as capillary chromatography. For purposes of the following description, the terms "therapeutic," "insulin," or "fluid" are used interchangeably, however, in other embodiments, any fluid may be used, as previously described. Thus, the devices and descriptions contained herein are not limited to therapeutic uses.

[0040] Some embodiments of the fluid delivery device are adapted for use by people living with diabetes and / or their caregivers. Thus, in these embodiments, the devices, methods, and systems serve to deliver insulin that assists or supplements the action of the pancreatic islet cells of a person living with diabetes (referred to as the user). The embodiments adapted for insulin delivery seek to mimic the action of the pancreas by providing both a basal level of fluid delivery as well as a bolus level of delivery. The basal level, bolus level, and timing may be set by the user or caregiver by using a wireless handheld user interface, or directly by using the pump. Furthermore, the basal and / or bolus levels may be triggered or adjusted in response to the output of a glucose meter, which in an exemplary embodiment is integrated into the controller. In other embodiments, the controller further includes a glucose monitoring device that receives data from a blood glucose sensor. In some embodiments, the bolus may be triggered by the user using a designated button or other input means located on the device, i.e., on the controller and / or on the infusion pump. In yet other embodiments, the bolus or basal may be programmed or administered through a user interface located either on the fluid delivery device / infusion pump and / or on the controller.

[0041] With regard to the names given to the screens and types of screens, as well as the appropriate names given to the various features, throughout the various embodiments, these terms may vary.

[0042] The systems and methods described herein may be used to control an infusion pump. For purposes of this description, various embodiments of the user interface and infusion pump may be described with reference to an insulin pump, or a pump that infuses insulin. However, it should be understood that the user interface may be on the infusion pump and / or on the controller. Additionally, where the description refers to an infusion pump "screen," this "screen" may also appear on the controller, or may appear on the controller instead of the pump.

[0043] Infusion pumps contemplated by this description include pumps that may pump any fluid, including, but not limited to, therapeutic fluids, including, but not limited to, insulin. Thus, while this description describes exemplary embodiments in the context of insulin, this is merely for purposes of illustration and the device is not intended to be limited to insulin. Other fluids are also contemplated. In some embodiments, the methods, systems, and devices described herein may be used in conjunction with insulin "pens" and / or fluid delivery "pens," as are well known in the art.

[0044] The infusion pump may be any infusion pump, including, but not limited to, the pump devices shown and described in connection with Figures 1A-1F, which are incorporated herein by reference. In various exemplary embodiments, the infusion pump is a syringe-pump, i.e., fluid is pumped or delivered to the user when a plunger advances through a syringe, forcing fluid inside the syringe into a cannula. When the cannula is connected to the user (i.e., the cannula is in the subcutaneous area of ​​the user), fluid is delivered subcutaneously to the user.

[0045] In an exemplary embodiment, the infusion pump includes hardware for wireless RF communication with the controller. However, in various embodiments, the infusion pump may be any infusion pump. With reference to FIGS. 1A-1F and 2A-2D, in some exemplary embodiments, the infusion pump may include a display assembly 104, however, in other exemplary embodiments, such as those shown in FIGS. 2A-2D, the infusion pump may not include a display assembly. In these embodiments, a display assembly, which may be similar to that shown in FIGS. 1A, 1D, and 1F, or may be larger or smaller, is included on the controller or companion device. An embodiment of a controller or companion device is shown in FIG. 3.

[0046] 1A-1F, an embodiment of an infusion pump assembly 100 is shown that may be housed within an enclosure assembly 102. The infusion pump assembly 100 may include a display system 104 that may be visible through the enclosure assembly 102. One or more switch assemblies / input devices 106, 108, 110 may be disposed about various portions of the enclosure assembly 102. The enclosure assembly 102 may include an infusion port assembly 112 to which a cannula assembly 114 may be releasably coupled. A removable cover assembly 116 may provide access to a power source cavity 118 (shown in phantom in FIG. 1D).

[0047] With reference to the infusion pump assembly shown in FIGS. 1A-1F, infusion pump assembly 100 may include processing logic, referred to as a pump processor (not shown), that executes one or more processes that may be required for infusion pump assembly 100 to operate properly. The processing logic may include one or more microprocessors (not shown), one or more input / output controllers (not shown), and a cache memory device (not shown). One or more data buses and / or memory buses may be used to interconnect the processing logic with one or more subsystems. In some embodiments, at least one of the subsystems shown in FIG. 4 is also included in the embodiment of infusion pump assembly 200 shown in FIGS. 2A-2D.

[0048] 1A-1F and 4, examples of subsystems interconnected with processing logic 400 may include, but are not limited to, memory system 402, input system 404, display system 406, vibration system 408, acoustic system 410, motor assembly 416, force sensor 412, temperature sensor (not shown), and displacement detection device 418 (which may be referred to as a device for determining and / or detecting a distance a plunger has moved relative to a syringe barrel / syringe). Infusion pump assembly 100 may include a main power source 420 (e.g., a battery) configured for removal from and insertion into power source cavity 118 and configured to provide power to at least a portion of processing logic 400 and one or more of the subsystems (e.g., memory system 402, input system 404, display system 406, vibration system 408, acoustic system 410, motor assembly 416, force sensor 412, and displacement detection device 418).

[0049] Infusion pump assembly 100 may include a reservoir assembly 430 configured to contain an infusible fluid 422. In some embodiments, reservoir assembly 430 may be a reservoir assembly similar to those described in U.S. Pat. No. 7,498,563, issued Mar. 3, 2009, and entitled Optical Displacement Sensor for Infusion Devices, which are incorporated herein by reference in their entireties, and / or U.S. Pat. No. 7,306,578, issued Dec. 11, 2007, and entitled Loading Mechanism for Infusion Pump, International Application No. PCT / US2009 / 060158, filed Oct. 9, 2009, and entitled Infusion Pump Assembly, and U.S. Patent Application Publication No. US-2010-0094222, published Apr. 15, 2010, and now entitled Infusion Pump Assembly, which are incorporated herein by reference in their entireties. No. 12 / 249,882 to U.S. Pat. No. 6,393,911, all of which are incorporated herein by reference in their entireties. In other embodiments, the reservoir assembly may be any assembly in which fluid may be acted upon such that at least a portion of the fluid may flow out of the reservoir assembly, for example, the reservoir assembly may include, but is not limited to, a barrel having a plunger, a cassette, or a container constructed at least in part of a flexible membrane in various embodiments.

[0050] Plunger assembly 424 may be configured to displace infusible fluid 422 from reservoir assembly 430 through cannula assembly 450 (which may be coupled to infusion pump assembly 100 via injection port assembly 424) so ​​that infusible fluid 422 may be delivered to a user 454. In this particular embodiment, plunger assembly 424 is shown as being displaceable by partial nut assembly 426, which may engage lead screw assembly 428, which may be rotatable by motor assembly 416, in response to a signal received from processing logic 400. In this particular embodiment, the combination of motor assembly 416, plunger assembly 424, partial nut assembly 426, and lead screw assembly 428 may form a pump assembly that provides for the dispensing of infusible fluid 422 contained within reservoir assembly 430. Examples of partial nut assembly 426 may include, but are not limited to, a nut assembly configured to wrap around lead screw assembly 426 by, for example, 30 degrees. In some embodiments, the pump assembly may be similar to those described in U.S. Patent No. 7,306,578, entitled Loading Mechanism for Infusion Pump, issued on December 11, 2007; U.S. Patent Application No. 12 / 249,882, entitled Infusion Pump Assembly, filed on October 10, 2008, published on April 15, 2010, now titled U.S. Patent Application Publication No. US-2010-0094222; and U.S. Patent Application No. 12 / 249,891, entitled Infusion Pump Assembly, filed on October 10, 2008, published on April 16, 2009, now titled U.S. Patent Application Publication No. US-2009-0099523, entitled Infusion Pump Assembly, all of which are incorporated herein by reference in their entireties.

[0051] (User Interface) Throughout this description, a screen may be referred to in terms of a "pump" or a "companion" or a "controller". However, in various embodiments, a similar screen or similar method may be accomplished on another device. For example, where a screen or method is referred to in terms of a "pump", a similarly functional screen or method may be used on a "companion" or a "controller" in other embodiments. Because this description includes embodiments relating to both pumps with displays and pumps without displays, it should be apparent that if an embodiment includes an infusion pump without a display, any screens will be visible on the companion or controller. Similarly, where a method requires interaction between a user and a pump, if the pump is an infusion pump without a display, the interaction may be accomplished via a switch assembly on the pump.

[0052] In some embodiments, processing logic including at least one element is used to receive input from a user or caregiver, as shown and described with respect to Figure 4. The user or caregiver uses one or more input devices or assemblies including, but not limited to, one or more of a button / switch assembly, a slider assembly including, but not limited to, a capacitive slider (e.g., which may include, but is not limited to, any slider described in U.S. Patent Application No. 11 / 999,268, filed December 4, 2007 and entitled Medical Device Including a Slider Assembly, now U.S. Patent Application Publication No. US-2008-0177900, published July 24, 2008, all of which are incorporated herein by reference in their entireties), a jog wheel, and / or a touch screen. The infusion device additionally receives inputs from internal systems, including, but not limited to, an occlusion detection process 438, a confirmation process 440, volumetric measurement techniques (e.g., acoustic volumetric sensing). Using these inputs, the infusion device provides outputs, including, but not limited to, for example, infusion fluid delivery to the user, or a comment, alert, alarm, or warning to the user. Thus, inputs are either directly from the user to the pump, directly from the pump system to the processing logic, or from another device, e.g., a remote controller device (described in more detail below), to the pump. Thus, the user or caregiver interaction experience includes, but is not limited to, one or more of interactions with a display (either on the infusion pump device itself or on a remote controller device, or both), including, but not limited to, reading / seeing text and / or graphics on the display, direct interaction with the display, e.g., through a touch screen, interaction with one or more buttons, sliders, jog wheels, one or more glucose strip readers, and sensing through either haptics or sound, one or more vibration motors, and / or sound systems.Thus, the term "user interface" is used to encompass all systems and methods by which a user or caregiver interacts with and controls the infusion pump.

[0053] 3, in some embodiments of the infusion pump system, the infusion pump may be remotely controlled using a remote controller assembly 300, also referred to as a controller or companion. The remote control assembly 300 may include all or a portion of the functionality of the infusion pump assembly itself as shown in FIGS. 1A-1F. Thus, in some exemplary embodiments of the infusion pump assembly described above, the infusion pump assembly (not shown, see FIGS. 1A-1F, among other figures) may be configured via the remote control assembly 300. In these particular embodiments, the infusion pump assembly may include telemetry circuitry (not shown) that allows communication (e.g., wired or wireless) between the infusion pump assembly and, for example, the remote control assembly 300, thus enabling the remote control assembly 300 to remotely control the infusion pump assembly 100. The remote control assembly 300 (which may also include telemetry circuitry (not shown) and may be capable of communicating with the infusion pump assembly) may include a display assembly 302 and an input assembly, which may include one or more of an input control device (such as a jog wheel 306, a slider assembly 310, or another conventional mode for input to the device), and switch assemblies 304, 308. Thus, the remote control assembly 300 includes a jog wheel 306 and a slider assembly 310 as shown in FIG. 3, although some embodiments may include only one of the jog wheel 306 or the slider assembly 310, or another conventional mode for input to the device. In embodiments having a jog wheel 306, the jog wheel 306 may include a wheel, ring, knob, or the like, which may be coupled to a rotary encoder or other rotary transducer to provide a control signal based, at least in part, on the movement of the wheel, ring, knob, or the like.

[0054] The remote control assembly 300 may include the ability to preprogram basal rates, bolus alarms, delivery limits, and may also allow the user to view history and establish user preferences. The remote control assembly 300 may also include a glucose strip reader 312.

[0055] During use, the remote control assembly 300 may provide instructions to the infusion pump assembly via a wireless communication channel established between the remote control assembly 300 and the infusion pump assembly. Thus, a user may use the remote control assembly 300 to program / configure the infusion pump assembly. Some or all of the communications between the remote control assembly 300 and the infusion pump assembly may be encrypted to provide an increased level of security.

[0056] In an exemplary embodiment of the user interface, the user interface may request user confirmation and user input. The exemplary embodiment of the user interface focuses on ensuring that the user understands the impact of various interactions on the pump. Throughout this description of the pump, many examples are presented that communicate the results of the user's actions to the user. These features ensure that the user understands the user's actions and therefore provide greater safety to the user. One such example is through an exemplary embodiment of the user interface, where the user presses a back button on a screen after a value is changed and the user interface displays a cancel changes confirmation screen, as shown in FIG. 6. If the user selects "Yes", the user interface discards any pending changes, closes the confirmation screen, and returns to the previous screen (i.e., the screen before the screen where the user pressed the back button). When the action selection on the "Cancel changes?" confirmation screen is "No", the user presses a confirm button or other button depending on the embodiment and the user interface closes the confirmation screen and returns to the screen with the pending changes. This feature prevents the outcome where the user believes changes have been implemented, when in fact they have not, so this feature prevents that situation and ensures that the user understands that changes have not been implemented.

[0057] (temperature) In various embodiments of the infusion pump, the user may wear the infusion pump attached to a belt, attached to another article or clothing, i.e., clothing such that the device is worn on the body, or in some embodiments, in a pocket attached to underwear, or in some embodiments, attached to the user's skin. The user generally wears the infusion pump as close to 24 hours a day as possible, and in some cases removes the device for short periods of time, such as, but not limited to, during MRIs or other treatments that may affect the device, and / or during showers / baths. Thus, during the normal course of a user wearing the infusion pump, the infusion pump may be exposed to a variety of temperatures, including temperature fluctuations that may include positive and / or negative temperature fluctuations. These temperature fluctuations may be the result of the user going outside, entering a cold room, entering a warm room, and / or being under a blanket or other heating material.

[0058] As mentioned above, the fluid contained in the reservoir while in the pump, which may include but is not limited to insulin, has a coefficient of thermal expansion, which may generally be referred to as the volumetric coefficient of thermal expansion. Thus, during temperature fluctuations / differentials / changes, whether positive or negative, the fluid, i.e., insulin, will expand or contract. Various factors may contribute to the expansion or contraction of the fluid, including but not limited to the rate of temperature change. Thus, in some embodiments, the amount of expansion or contraction may be a function of temperature.

[0059] Furthermore, in various embodiments of the described devices, the pump components also have thermal expansion coefficients. These thermal expansion coefficients may vary depending on the material. Thus, if the various components are constructed from different materials, the thermal expansion coefficients may vary.

[0060] In some embodiments, a temperature change may affect the thermal expansion or contraction of the fluid and / or one or more components of the infusion pump. For example, but not by way of limitation, an increase in temperature may result in an increase in the diameter of the reservoir / syringe 430 (see FIG. 4, by way of example only). This may be because the relative thermal expansion of the syringe compared to the fluid influences whether the fluid is delivered or drawn. This may then cause any fluid / insulin in the cannula 450 to flow back towards the reservoir 430. In this case, the volume of fluid / insulin is drawn back into the reservoir. Thus, a subsequent delivery request by the processing logic 400 may result in only this withdrawn volume being delivered to the user. Thus, the volume of fluid / insulin (the withdrawn volume) has not been delivered to the user without the user's request or understanding. Another example includes a decrease in temperature. In some embodiments, a decrease in temperature may cause the diameter of the reservoir 430 to decrease, causing the fluid / insulin to flow into the cannula 450. Thus, an unintended bolus volume is delivered to the user. In this case, fluid / insulin is being delivered to the user without any request or knowledge by the user.

[0061] Thus, in a first example, the user may receive less fluid / insulin than needed or requested and therefore experience hyperglycemia. In a second example, the user may receive more fluid / insulin than needed or requested and therefore experience hypoglycemia. In either example, the user may receive a volume of fluid / insulin that is not identical to the requested or programmed therapy and not be notified of the difference.

[0062] In these examples, the reservoir is assumed to be cylindrical. Below is a mathematical model of the volume change for a cylinder (assuming a constant linear expansion coefficient α). This is a model for illustrative purposes. Additional mathematical models can be determined below to accommodate additional assumptions, such as shapes other than cylindrical, or syringes with movable plungers.

[0063]

number

[0064]

number

[0065] Therefore, the linear expansion coefficient

[0066] [ka] For polypropylene, a material having a temperature of 30°C to 10°C, the volume change of a cylindrical object made of polypropylene is

[0067]

number

[0068] The specific volume change of water from 30C to 10C is about 0.40%. The difference between the two (about 0.12%) applied to a 3cc syringe or reservoir would be about 3.6 μL. However, the syringe plunger may also move in response to thermal expansion depending on the plunger material and the relationship of the syringe within the pump (e.g., the design of the syringe retention within the pump).

[0069] Thus, it may be desirable to minimize the effect of temperature on the delivery of the fluid. Thus, it may be desirable to limit or minimize and / or characterize the thermal expansion of the fluid and / or one or more of the components of the infusion pump. The described systems, methods, and apparatus for minimizing the effect of temperature on the thermal expansion of the fluid and / or one or more of the components of the infusion pump may include one or more of the following exemplary embodiments.

[0070] In some embodiments, the selection of a material with a predictable and favorable coefficient of thermal expansion can minimize the possibility of under- and over-filling the fluid, as discussed above. In some embodiments, the syringe material may be selected, for example, to match the thermal expansion of the fluid. For example, the linear coefficient of expansion of water at about 20 C is approximately

[0071]

number

[0072] Thus, the syringe material may be selected to have a coefficient of expansion close to this value. For example, a blend of polycarbonate and acrylonitrile butadiene styrene (also referred to as "ABS") may be used to match the thermal expansion coefficient of the fluid. In some embodiments, other plastics, such as but not limited to polycarbonate, may be close to the exact coefficient of expansion such that the volume delivered by the syringe pump due to the measured temperature change is minimal and / or acceptable. In some embodiments, the plastic or material selected may be tuned to the gradient of thermal expansion of the fluid.

[0073] In some embodiments, the materials of the plunger and / or plunger rod may be selected to thermally differentially compensate for temperature changes. In some embodiments, the materials for the syringe, plunger, and plunger rod may be selected to thermally differentially compensate for temperature changes. Also, or in addition, in some embodiments, the materials of one or more components of the drivetrain or any other component of the infusion pump may be selected to thermally differentially compensate for temperature changes.

[0074] In some embodiments, materials for any one or more of the infusion pump components may have an inverse thermal coefficient or thermal compensation material and be selected to minimize the thermal expansion effects of temperature. For example, at higher temperatures the infusion pump syringe expands and the flow of fluid may become negative. In some embodiments, at least one component of the drivetrain may have a negative thermal constant and therefore an inverse thermal coefficient. Thus, in response to an increase in temperature, the syringe does not undergo a volume change.

[0075] In some embodiments, the use of a material that can undergo a phase change during a temperature change event can minimize the effect of temperature differentials / changes on the infusion pump. For example, in some embodiments, the plunger may contain a predetermined volume of wax, and therefore as the temperature increases, the length or position may increase due to the phase change of the wax. Additional wax features may be added in some embodiments to prevent flow. In some embodiments, wax features may be added to move the plunger forward a (predetermined) distance such that the resulting change in volume is equal to the square root of the plunger diameter. Thus, in some embodiments, the use of a material that undergoes a phase change in response to temperature / temperature change / differential may be used to compensate for the change in volume of the syringe due to temperature changes. In some embodiments, the material that undergoes a phase change in response to temperature change can absorb the thermal differential energy, and thus, for example, if the temperature is increasing, but not the temperature increase of the infusion pump, the wax or other phase change material may melt the wax / phase change material, thus acting as an energy sink and absorbing heat.

[0076] In some embodiments, the syringe may be constrained such that a temperature change may cause the plunger to advance or withdraw to compensate for the volume change of the syringe. For example, in some embodiments, the syringe may be held in a metal case, and metals that may be used include, but are not limited to, any metal with a low coefficient of thermal expansion, which may include, but are not limited to, steel, aluminum, and / or FeNi36, also known as INVAR®. The plunger may be made of a material with a high coefficient of thermal expansion. Thus, in this example, a decrease in temperature may cause the syringe plunger to withdraw as the diameter of the syringe barrel decreases. Thus, to balance these effects, the total volume change may be minimized.

[0077] (Characterization and Control Compensation) In some embodiments, characterizing the effect of temperature change on the volume of fluid pumped by the infusion device may be envisioned. In this embodiment, the pump may be subjected to temperature fluctuations (i.e., both positive and negative) and the corresponding response by the infusion pump may be recorded. Characterization may include, but is not limited to, the rate of change (i.e., 1 degree Celsius / minute, whether positive and negative, etc.), the total temperature fluctuation (e.g., 10 degrees Celsius, 5 degrees Celsius, etc.), and / or the position of the syringe plunger.

[0078] The infusion pump may include one or more devices and / or components and / or systems for determining temperature. In some embodiments, the infusion pump may include one or more thermistors or other temperature sensors for determining temperature. However, in other embodiments, various methods and / or devices and / or systems for directly or indirectly determining temperature may be used, including, but not limited to, one or more of at least one resistive temperature device (RTD) and / or at least one non-contact infrared device (non-contact IR). The location of the one or more thermistors and / or temperature determining devices may vary. The location of the one or more thermistors and / or temperature determining devices may include, but is not limited to, the drive screw, anywhere on the drive train, on the syringe barrel (including, but not limited to, printed on the syringe barrel, plunger, and / or printed circuit board). In various embodiments, the one or more thermistors and / or temperature determining device locations may be anywhere away from a heat source that would potentially result in erroneous readings. In some embodiments, one or more thermistors may determine the temperature at one or more locations, including, but not limited to, inside the syringe, outside the syringe, inside the pump, and / or outside the pump. Various controls may be determined based on the temperature model at any one or more of these locations. Thus, in some embodiments, characterization may be performed by taking temperature readings both in the syringe and outside the syringe. In other embodiments, characterization may be performed by taking temperature readings from outside the pump and from inside the pump. In various embodiments, one or more thermistors and / or temperature determining devices are preferably installed in the same location on the pump for use by the user to remain in place during characterization.

[0079] In some embodiments, characterization may be completed by measuring the volume of fluid delivered as a function of temperature. In some embodiments, this may be accomplished by using a thermal chamber and an infusion set / cannula connected to a reservoir / syringe to deliver the fluid in precise scale. However, in other embodiments, this may be completed by using a thermal chamber and an infusion set / cannula connected to a reservoir / syringe to deliver the fluid and then determining the position of a plunger inside the reservoir and determining the total volume of fluid delivered.

[0080] In some embodiments, the temperature of the pump may in fact be measured (at one or more locations and / or taken by one or more thermistors) and the target position of the plunger may be varied as a function of temperature to compensate for thermal expansion of the syringe and / or plunger. Thermal expansion readings may be determined by reference to characterization data, as described above. Thus, in some embodiments, the target position may be corrected based on a look-up table or function approximation of the syringe volume change with temperature.

[0081] In some embodiments, the infusion pump delivers fluid as a basal or bolus delivery, and / or variants thereof. Basal delivery is a programmed rate or volume / time. The infusion pump delivers a volume of fluid at predefined intervals for a predefined duration. The infusion pump may also deliver a bolus volume. A bolus is a requested volume of fluid that is delivered immediately, i.e., when a request is made. One embodiment of the bolus and basal delivery method is described in International Application No. PCT / US2009 / 060158, filed Oct. 9, 2009, entitled Infusion Pump Assembly, now International Publication No. WO2010 / 042814, published Apr. 15, 2010, and U.S. Patent Application No. 12 / 249,882, filed Oct. 10, 2008, entitled Infusion Pump Assembly, now U.S. Patent Application Publication No. US-2010-0094222, published Apr. 15, 2010, all of which are incorporated herein by reference in their entireties. Additionally, in some embodiments, such as those described in U.S. Patent No. 7,498,563, issued March 3, 2009, entitled Optical Displacement Sensor for Infusion Devices, which is incorporated herein by reference in its entirety, the infusion pump may determine the distance it must travel to deliver a volume of fluid, such as a basal volume or a bolus volume. Thus, in some embodiments of the infusion pump system, the infusion pump may use an optical displacement sensor to verify the distance the plunger is moved during a delivery. In some embodiments, the infusion pump determines the number of motor encoder counts per delivery to verify plunger movement.

[0082] However, in various embodiments, the delivery method includes determining the distance the plunger must travel to deliver the desired / target volume (which may be referred to as the target plunger position). As previously mentioned, this may be done by determining the number of motor encoder steps, or in other embodiments, in other ways. In any event, the infusion pump makes the determination of the plunger distance travel.

[0083] One example of a characterization and control compensation method is as follows: The first step may be to characterize the volume delivered as the temperature changes. This volume may be a function of the amount of fluid contained in the syringe (call it V) due to variations in the thermal expansion properties of the plastic and the liquid / fluid, which in turn are a function of temperature (call it T). A function β(T) relating the volume change to temperature change may be used.

[0084]

number

[0085] The coefficient β(T) can be determined as a function of temperature (as shown above) or, possibly, approximated as a constant determined as a function of both temperature and plunger position β(T,x).

[0086] The target plunger position can then be determined and adjusted. The target position x can be calculated using the following formula:

[0087]

number

[0088] [ka] Substituting (when the plunger reaches the end of its travel and expels all of the fluid in the syringe, x=0), the relationship becomes

[0089]

number

[0090] In various embodiments, this correction may be done in different ways, including but not limited to the following: In some embodiments, the correction may be done by delivering based on an interval that may be more frequent than the basal delivery interval, which may be, for example, but is not limited to, delivery once every 3 minutes, but may be more or less frequent in other embodiments. Additionally, the position of the syringe may be adjusted based on temperature changes to maintain zero net volume delivered between regular deliveries, e.g., basal and / or bolus deliveries. In some embodiments, this may be used for low basal rates, where the thermally driven volume may exceed the regularly scheduled basal delivery. However, this may require reversing the syringe direction and preventing delivery in some embodiments.

[0091] Another embodiment may include applying a correction when the fluid / insulin is scheduled for delivery. Thus, the target plunger position may be corrected based on the measured temperature change and the predicted thermally driven volume delivery. In some of these embodiments, the correction may be limited such that the plunger can only be driven in one direction.

[0092] In some embodiments, the modeling may vary and assumptions may be made regarding both the length and diameter of the syringe. Additionally, assumptions may be made regarding the effect of temperature on the thermal expansion coefficient of one or more components of the infusion pump, including, but not limited to, the drive train, plunger, plunger rod, infusion pump housing, and cannula.

[0093] In some embodiments, adjusting the plunger target may include adjusting the target closer to or further from the syringe outlet. In some embodiments, the plunger advancement may be modified. In other embodiments, the plunger may be driven backwards to compensate for temperature. However, in some embodiments, depending on the infusion pump, it may be desirable to limit the adjustment closer to the syringe outlet. This may be due to the possibility of backlash.

[0094] In some embodiments, a temperature dependent basal rate may be preprogrammed into the pump for temperature compensation. In these examples, the pump processor receives data from at least one temperature sensor. If the temperature data indicates that the temperature or rate of temperature change is such that an adjustment should be made, the processor may signal to modify the preprogrammed basal rate. In some embodiments, this modification may be an addition or decrease in the basal rate by a predefined percentage, for example, a 30% increase or a 15% decrease. Of course, these are only examples and in these embodiments, the predefined modification may be determined differently than described.

[0095] In some embodiments, the infusion pump may include at least one temperature sensor and at least one optical sensor. In some embodiments, the optical sensor may be used to determine that the plunger has advanced. In some embodiments, the distance of advancement may also be determined. In some embodiments, a miniature reflective optical sensor (hereinafter "optical sensor") is used that fits the form factor of the infusion pump hardware. The optical sensor has a sensing range that overlaps with the plunger displacement. In an exemplary embodiment, any optical sensor may be used, including but not limited to the Sharp GP2S60 manufactured by Sharp Electronics Corporation, a US subsidiary of Sharp Corporation (Osaka, Japan). This optical sensor contains an infrared emitting diode and an infrared sensitive detector in a single package. The light from the emitter is unfocused and bounces off the sensing surface, some of which is returned to the detector, resulting in a sensing of the light intensity that varies as a function of the distance / angle to the reflector. In some embodiments, the sensor is positioned such that the reflective surface is the plunger.

[0096] In some embodiments, the optical sensor may be used to determine the level of fluid in the syringe / reservoir. This information may be used to determine if the plunger rod has advanced. Along with the temperature sensor information, this may provide additional data / information to determine temperature dependent changes.

[0097] In some embodiments of infusion pump systems, including those embodiments disclosed and described in U.S. Pat. No. 7,498,563, entitled Optical Displacement Sensor for Infusion Devices, issued on March 3, 2009, International Application No. PCT / US2009 / 060158, entitled Infusion Pump Assembly, filed on October 9, 2009, now titled International Publication No. WO2010 / 042814, published on April 15, 2010, and U.S. patent application Ser. No. 12 / 249,882, entitled Infusion Pump Assembly, filed on October 10, 2008, now titled U.S. Patent Application Publication No. US-2010-0094222, published on April 15, 2010 (all of which are incorporated herein by reference in their entireties), the infusion pump may include an optical displacement sensor. This sensor may be used to determine whether the plunger rod has advanced forward or backward, and the distance of advancement. Using this displacement information, along with information from one or more temperature sensors, the effect of temperature changes on the plunger may be determined. This determination may then improve the accuracy of the control used to compensate for the temperature change. This may include, but is not limited to, increasing the amount of fluid delivered by the sensed forward movement, and / or increasing the amount of fluid delivered by the sensed backward movement. In either case, the increase and / or decrease in basal rate and / or volume and / or bolus volume (e.g., by a percentage of the intended volume) is by a predetermined amount and for a predetermined time.

[0098] In some embodiments, the infusion pump system may include a system and / or method for adjusting the basal rate and / or bolus amount based on temperature change. Thus, in various embodiments, if the system determines that an upper or lower threshold temperature change has occurred, the system may automatically and / or upon request and / or confirmation by the user enter a mode having a limited period, for example, a uniform predefined limited time period, for example, 20 minutes, and / or in some embodiments, the mode may continue until the temperature change threshold is no longer applicable. In some embodiments, for example, if a decreasing temperature gradient is a primary concern, the infusion pump processor may be preprogrammed with a "decreasing gradient" mode, and the infusion pump may intentionally under-deliver in this mode, i.e., automatic percentage reduction of the basal rate, and in some embodiments, the bolus may also be set to compensate for the predicted additional delivery of fluid. As previously mentioned, the determination of the percentage change in insulin delivery may depend on the characterization of the infusion pump.

[0099] Then, in some embodiments, for example, if the basal rate gradient is a primary concern, the infusion pump processor may be preprogrammed with an "increasing basal rate" mode and the infusion pump may intentionally over-deliver, i.e., in an automatic percentage increase of the basal rate, and in some embodiments, a bolus may also be set to compensate for the predicted additional delivery of fluid. As previously mentioned, the determination of the percentage change may depend on the characterization of the infusion pump.

[0100] (Closed loop temperature compensation) For purposes of this description, the term "advanced" refers to the movement of the plunger within the syringe or reservoir body. Advancement is not limited to movement in a particular direction. The syringe has an outlet end, which is the end of the syringe where fluid moves internally to externally from the syringe.

[0101] In some embodiments, the system may include one or more devices and / or sensors that may include to determine the effect of temperature on the syringe / plunger and / or the pumping of fluid towards or away from the user / cannula. These devices and / or sensors may include, but are not limited to, one or more flow sensors, one or more occlusion devices and / or one or more binary valves, and / or one or more strain beams or sensors, and / or one or more optical sensors, and / or one or more temperature sensors, and / or one or more ultrasonic range sensors, and / or one or more potentiometers, and / or one or more rotor encoders, and / or one or more linear encoders.

[0102] With regard to the optical sensor, in some embodiments, the infusion pump may include at least one temperature sensor and at least one optical sensor. In some embodiments, the optical sensor may be used to determine that the plunger has advanced. In some embodiments, the distance of advancement may also be determined. In some embodiments, a miniature reflective optical sensor (hereinafter "optical sensor") is used that fits the form factor of the infusion pump hardware. In various embodiments, the optical sensor has a sensing range that overlaps with the plunger displacement. In various embodiments, any optical sensor may be used, including, but not limited to, one or more of the Sharp GP2S60, Sharp GP2S700, and Sharp GP2A240LC (all manufactured by Sharp Electronics Corporation, a US subsidiary of Sharp Corporation, Osaka, Japan). This optical sensor contains an infrared emitting diode and an infrared sensitive detector in a single package. The light from the emitter is unfocused and bounces off the sensing surface, some of which is returned to the detector, resulting in a sense of the light intensity, which varies as a function of the distance / angle to the reflector. In some embodiments, the sensor is positioned such that the reflective surface is the plunger.

[0103] In some embodiments, the optical sensor may be used to determine the level of fluid in the syringe / reservoir. This information may be used to determine if the plunger rod has advanced. Along with the temperature sensor information, this may provide additional data / information to determine temperature dependent changes.

[0104] In some embodiments of the infusion pump system, the infusion pump may include an optical displacement sensor. This sensor may be used to determine whether the plunger rod has advanced forward (towards the syringe outlet) or backward (away from the syringe outlet) and the distance of advancement. Using this displacement information, along with information from one or more temperature sensors, the effect of temperature changes on the plunger may be determined. This determination may then improve the accuracy of the controls used to compensate for the temperature changes. This may include, but is not limited to, a reduction in the amount of fluid delivered due to the sensed forward movement (i.e., a reduction in the volume of fluid scheduled to be delivered, i.e., basal rate, or requested to be delivered, i.e., bolus volume) and / or an increase in the amount of fluid delivered due to the sensed backward movement.

[0105] In some embodiments, the infusion pump may include an outlet valve and / or an occluder. Thus, in these embodiments, the infusion pump includes at least one device to prevent delivery of fluid from the syringe to the cannula and / or from the cannula to the user. In some embodiments, the device is activated when at least one temperature sensor sends a signal to the processor, which determines that the temperature change meets a threshold, i.e., the temperature change is large enough to affect the change in delivery due to temperature. In some embodiments, this may activate the occluder and / or outlet valve, preventing fluid from flowing into or out of the syringe and / or cannula. In some embodiments, the occluder and / or outlet valve device is released when at least one temperature sensor sends a signal to the processor, which determines that the temperature change no longer meets the threshold, i.e., the temperature change is no longer large enough to affect the change in delivery due to temperature. In some embodiments, this may release the occluder and / or outlet valve, allowing fluid to flow out of the syringe and / or into the cannula and / or to the user. Again, as mentioned above, in some embodiments, the plunger target may be adjusted in response to information from one or more temperature sensors.

[0106] In some embodiments, the occluder / outlet valve may be closed during intervals when the infusion pump is not actively delivering fluid to prevent accidental fluid flow into or out of the syringe / reservoir due to temperature changes. During times when the infusion pump is not actively delivering fluid, at least one temperature sensor may continue to send a signal indicative of temperature to the processor. This information may be used by the control system to determine whether and how to modify the "next delivery" of fluid, i.e., the next plunger target. Thus, when the "next delivery" is to occur, the occluder / outlet valve may open and fluid may be delivered.

[0107] Thus, in these embodiments, the occluder / outlet valve may act primarily to prevent spontaneous unintended fluid flow that may result from temperature changes. The control system may adjust the volume delivery, i.e., plunger target, based on temperature changes so that the volume of fluid delivered compensates for the temperature change.

[0108] In some embodiments, the infusion pump may include an adaptive component. In some embodiments, the adaptive component may change the volume difference in the syringe / reservoir while maintaining the pressure constant. Thus, in these embodiments, the controller compensation may not need to compensate for temperature changes when the occluder / outlet valve is opened, since there would be no pressure built up from temperature changes.

[0109] In some embodiments, once a threshold temperature change is determined, the occluder / outlet valve may be closed and the plunger rod may be floated, i.e., the plunger rod may be disengaged from the drive train. Thus, pressure changes will cause the plunger to float and achieve equilibrium, and thus adjust without the need for controller compensation, in response to temperature changes.

[0110] In some embodiments, the infusion pump may include at least one flow sensor, including, but not limited to, a flow sensor disposed in the outlet flow path. The flow sensor may detect fluid flow. This information may be correlated with the delivery command and a determination may be made whether the fluid delivered is as requested and / or a proper delivery. In some embodiments, if flow is detected and it is determined that the fluid delivered is not as requested and / or a proper delivery, the occluder and / or outlet valve may be closed. Thus, in some embodiments, the flow sensor may determine inward or outward fluid flow, and if this is not a predicted event, the infusion pump may activate at least one mechanism, including, but not limited to, an occluder and / or a valve, to prevent continued flow of fluid. Additionally, the flow information may be used to determine the amount or volume of fluid delivered or flowed inward, which may be used to modify the plunger target during the next scheduled or requested delivery (e.g., basal or bolus) or, in some embodiments, to modify the delivery schedule. In some embodiments, this may be completed without user interaction. In some embodiments, an alert may be sent to the user, who must accept the proposed course of action or to mitigate the under- or over-delivery of fluid.

[0111] In some embodiments, the infusion pump may include one or more optical sensors. These sensors may be located in the infusion pump to determine the level of fluid in the syringe / reservoir. The one or more optical sensors may determine the level of fluid before and after the processor signals the drivetrain to advance the plunger. Thus, the volume difference may be determined before and after the plunger is advanced. However, the at least one optical sensor may collect data at predefined intervals in some embodiments, regardless of whether the drivetrain is activated. Thus, the at least one optical sensor may collect information to determine when and if the plunger is advanced and / or when and if fluid is delivered or retracted. Thus, the at least one optical sensor may collect data for the processor to determine when an unsolicited delivery event may have occurred. The processor may correlate this information with the at least one temperature sensor, thereby determining if the infusion pump is experiencing temperature-related effects. In some embodiments, the processor may alert the user. In some embodiments, the information may be used to cause a control algorithm to compensate for the effects of temperature changes, for example, but not limited to, using various embodiments discussed herein.

[0112] In some embodiments, a strain beam may be used to identify the plunger moving away from the syringe outlet. In these embodiments, the strain beam may be positioned relative to the plunger rod such that it senses strain when the plunger rod begins to move away from the syringe outlet. In some embodiments of the infusion pump system, the infusion pump includes a strain beam that may be used to detect and / or identify an occlusion. The strain beam and method may, in some embodiments, be similar to those described in U.S. Patent Application Serial No. 12 / 249,882, entitled Infusion Pump Assembly, filed October 10, 2008, now entitled Infusion Pump Assembly, U.S. Patent Application Publication No. US-2010-0094222, published April 15, 2010, and International Application No. PCT / US2009 / 060158, entitled Infusion Pump Assembly, filed October 9, 2009, now entitled Infusion Pump Assembly, WO2010 / 042814, published April 15, 2010, all of which are incorporated herein by reference in their entirety. However, in conjunction with at least one temperature sensor, the strain beam may determine whether a particular temperature change caused the plunger movement. If plunger movement is detected by a temperature change, the infusion pump may alert the user. In some embodiments, the system may correlate changes in strain with changes in temperature.

[0113] (temperature maintenance) As previously mentioned, it may be desirable to maintain the temperature of the infusion pump to avoid any consequences from temperature changes. In some embodiments, one or more of a variety of devices and / or systems may be employed to maintain the temperature of the infusion pump to minimize or prevent the aforementioned effects of temperature changes on the infusion pump and fluid delivery.

[0114] In some embodiments, the infusion pump includes a heating device. The heating device may receive instructions from the processor. The heating device may be located anywhere in or on the infusion pump, however, in some embodiments, the heating device is located within the infusion pump housing. In some embodiments, the heating device is powered by a power source or battery inside the infusion pump. However, in some embodiments, the power source may be external to the infusion pump.

[0115] The heating source may be any heating source desired, however, in an exemplary embodiment, the heating source may be a KAPTON® (Polyimide Film) Heater kit available from omega.com® under part number KH-KIT-EFH-15001. In some embodiments, at least one temperature sensor is located in or on the infusion pump. The at least one temperature sensor may communicate information to the processor. Based on the temperature sensor data, the processor may act as a thermostat and provide power to the heating source to maintain the temperature within the infusion pump at the desired temperature. In some embodiments, the desired temperature may be between 15 and 30 degrees Celsius, although in other embodiments the maintained temperature may be different. In some embodiments, it may be desirable to maintain the temperature higher.

[0116] In some embodiments, the syringe / reservoir may be contained within a metal casing within the infusion pump, which may increase the conduction of heat between the heating element and the syringe / reservoir.

[0117] In some embodiments, at least one heating element may be located at one or more locations inside the infusion pump, one or more of which may be selected to maintain the temperature of one or more components of the infusion pump, including, but not limited to, the syringe, the fluid, the plunger, the housing, the plunger rod, and / or the drive train.

[0118] In some embodiments, the at least one heating element may further extend the power supply and / or battery life in the infusion pump. Maintaining the temperature at about 35 degrees Celsius may be beneficial to battery life and / or performance.

[0119] In some embodiments, it may be desirable to wear the infusion pump in close proximity to the user's skin, utilizing the user's body as a heat sink. This may be accomplished using a variety of devices and apparatus, including, but not limited to, one or more of the following:

[0120] For example, a hook-and-loop system, such as but not limited to those supplied by VELCRO® USA Inc. (Manchester, NH), may be utilized to allow easy attachment / removal of the infusion pump from the user. Thus, an adhesive patch may be attached to the skin of the user and may include an outwardly facing hook or loop surface. Additionally, the surface of the infusion pump 114 may include a complementary hook or loop surface. Depending on the separation resistance of the particular type of hook-and-loop system employed, the strength of the hook and loop connection may be greater than the adhesive strength to the skin connection. Thus, various hook and loop surface patterns may be utilized to adjust the strength of the hook and loop connection.

[0121] Also, referring to Figures 10A-10E, five examples of such hook and loop surface patterns are shown. For illustrative purposes, it is assumed that one surface of the infusion pump housing is coated in "loop" material. Thus, the strength of the hook and loop connection may be adjusted by varying the pattern (i.e., amount) of "hook" material present on the surface of the adhesive patch. Examples of such patterns may include, but are not limited to, a single outer circle 220 of "hook" material (as shown in Figure 10A), multiple concentric circles 222, 224 of "hook" material (as shown in Figure 10B), multiple radial spokes 226 of "hook" material (as shown in Figure 10C), multiple radial spokes 228 of "hook" material combined with a single outer circle 230 of "hook" material (as shown in Figure 10D), and multiple radial spokes 232 of "hook" material combined with multiple concentric circles 234, 236 of "hook" material (as shown in Figure 10E).

[0122] In another embodiment, a holder, pouch, bag, container, or other type of enclosure (generally referred to as a "holder") may be sized to accommodate the infusion pump. In some embodiments, the holder may be constructed to include multiple layers, including, but not limited to, one or more insulating layers. In some embodiments, one or more of the layers may include a fabric, where the layer provides a cooling effect when wet and refrigerated or frozen. This layer may be desirable in warmer weather or situations where the user's infusion pump may be exposed to the sun or a warm environment. In some embodiments, one or more of the layers of material may be a highly absorbent material. In some embodiments, the holder may include one or more containers of isopropyl alcohol, which, when employed, may be absorbed into the highly absorbent material of the holder and provide evaporative cooling to the infusion pump. In various embodiments, the holder may include alternative and / or additional methods, systems, and / or devices for cooling the infusion pump.

[0123] In some embodiments, the holder may include one or more temperature measuring devices and / or temperature sensors that may transmit information to the infusion pump and / or controller. The one or more temperature sensors may communicate the temperature of the holder and deploy one or more containers of alcohol and / or alert the infusion pump / user / controller and / or turn on a heating source based on the temperature sensor. In some embodiments, heating and / or cooling may be triggered by reaching a threshold temperature change. Thus, in some embodiments, the holder may provide a closed loop system to maintain temperature for the infusion pump.

[0124] 11, some embodiments of the holder 500 include an outer layer 502, an inner layer 504, and an inner pocket 506. The pocket 506 may include additional cushioning or insulation to protect the infusion pump from external forces and / or temperature changes. The holder 500 may include fasteners along the front, top, or sides. In some embodiments, the holder 500 may include a pull-down flap (not shown) on the front to expose the screen and / or input assembly (e.g., including but not limited to buttons, sliders, and / or jog wheels). In some embodiments, the flap may be secured closed using a hook-and-loop fastener system. In other embodiments, the flap may be secured using any other fastener system, including but not limited to snaps, buttons, magnetic closures, and zippers.

[0125] In some embodiments, the holder 500 may be attached to a strap 508 designed to be attached to a user (see, e.g., FIG. 12). However, in various embodiments, the strap 508 may be elastic and / or adjustable and may include at least one closure device. Although shown in FIG. 12 as being centered around the midsection of the user 510, the holder 500 may be worn anywhere the user desires.

[0126] 13, an embodiment of a back side of the holder 500 is shown. In some embodiments, the holder may include a clip 512, which may be referred to as a "belt clip" or another type of clip, configured to securely and removably fit over a belt, handle, piece of clothing, or the like. In some embodiments, the holder 500 may further include an opening 514 for tubing 516 to fit through. In some embodiments, an infusion pump (not shown) is contained inside the holder 500, and the holder may be mounted adjacent to a user's insertion site (not shown) such that the smallest tubing 516 is exposed to the outside temperature. Thus, an embodiment of the holder 500 that includes an opening 514 for tubing may be beneficial for maintaining the temperature of the tubing 516 and / or the fluid within the tubing.

[0127] In some embodiments, a plastic material, such as Press n' Seal, or another material of similar behavior may be used to attach and maintain the infusion pump against the user's body. In other embodiments, a cuff and band that fits, for example, against the user's leg, midsection, or arm may contain a pouch for the infusion pump. In other embodiments, the infusion pump may be maintained in place against the skin through an inner pocket, bra pocket, etc.

[0128] Various embodiments are described herein for maintaining the temperature of the infusion pump utilizing both the user's body heat and / or a heating element. However, additional devices and apparatus are within the scope of the invention. Additionally, the various methods, systems, and apparatus for maintaining the temperature of the infusion pump may include at least one temperature sensor.

[0129] (Insulin temperature) Described herein are various methods, systems, devices, and / or apparatus for maintaining the temperature of an infusion pump. Inherent in at least some of these embodiments is the maintenance of infusible fluid / insulin temperature. It is well known that insulin manufacturers recommend that the temperature of the insulin not exceed high and low temperatures. Furthermore, once the vial is used, it may be beneficial to maintain the immediate effect at room / ambient temperature (e.g., 59 to 86 degrees Fahrenheit) (e.g., HUMALOG®, NOVOLOG®), i.e., manufacturers recommend storing the insulin in a refrigerated area, e.g., 36 to 46 degrees Fahrenheit, until the vial is used. From that point on, it is recommended that the vial be stored at room temperature.

[0130] Because insulin can become less effective or ineffective when it reaches non-recommended temperatures, it can be beneficial for users to know if their insulin has been properly stored, whether during transportation, in the refrigerator, or during use.

[0131] 14, in one embodiment, a stick-on thermometer 520 may be placed on a vial 522 of fluid, and in some embodiments, on a vial of insulin. The thermometer may inform the user of the current temperature of the vial. In some embodiments, the temperature may be shown as different shades of red and blue to indicate different temperatures towards higher and lower ranges. In some embodiments, once the temperature reaches a maximum or minimum temperature (which is predetermined, and in some embodiments may be 35 and 87 degrees Fahrenheit, respectively), the thermometer becomes non-reversible, thus instantly indicating to the user that the insulin has reached a maximum or minimum temperature.

[0132] Any stick-on thermometer may be used, including non-reversible temperature labels, such as Non-Reversible Temperature Labels, 3 Temperature Ranges, or another similar temperature label available from omega.com® under part number TL-3. As mentioned above, in some embodiments, reversible labels or labels having both reversible and non-reversible components may be used.

[0133] While the principles of the present invention have been described herein, it will be understood by those skilled in the art that this description is made only by way of example and not as a limitation on the scope of the invention. Other embodiments are contemplated within the scope of the present invention in addition to the exemplary embodiments shown and described herein. Modifications and substitutions made by those skilled in the art are also deemed to be within the scope of the present invention.

Claims

[Claim 1] The invention as depicted in the drawings of this application.

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