Systems, devices, and methods for occlusion detection using pump performance measurements

Abstract

To provide a blockage detection system.SOLUTION: The present invention includes a pump controlled by suction dispensation stroke. A measurement device for pump measurement value generation is an end stop switch actuated at completion of the stroke. The switch is connected to a processing device for determining stroke duration. A metric is switch duration longer than a pump measurement value average with no blockage, and the pump measurement value includes two or more of switch duration, stroke duration, and an inter-stroke time difference. The metric corresponding to the stroke duration is selected duration shorter than a stroke duration average with no blockage. The metric of a dispensation stroke duration difference for suction stroke duration is selected duration larger than the stroke duration difference average with no blockage. A processing device of an injection device analyzes a pump measurement value, and determines when the pump measurement value includes a plurality of pump measurement values that satisfies what the metric corresponds to.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to systems, methods, and devices for occlusion detection. Exemplary embodiments of the present invention relate to occlusion detection using pump operation parameters such as pump duration (e.g., aspiration stroke duration or dispense stroke duration) in rotary metering or reciprocating pumps, or pump operation monitoring switch actuation, to eliminate the need to add additional pressure sensing components. [Background technology]

[0002] Diabetes is a group of diseases characterized by high blood sugar levels, resulting from the inability of diabetic patients to maintain adequate insulin production when needed.If diabetes is not treated, it can be dangerous for affected patients, and it can lead to serious health complications and early death.However, such complications can be minimized by utilizing one or more treatment options to help control diabetes and reduce the risk of complications.

[0003] Treatment options for diabetics include special diets, oral medications, and / or insulin therapy. An effective method of insulin therapy and diabetes management is infusion therapy or infusion pump therapy, in which an insulin pump is used. Insulin pumps can provide a continuous infusion of insulin to diabetics at various rates to more closely match the function and behavior of a properly functioning pancreas in a person without diabetes, which produces the required insulin, and can help diabetics maintain their blood glucose levels within a target range based on their individual needs. Infusion pump therapy requires an infusion cannula, typically in the form of an infusion needle or flexible catheter, that pierces the diabetic patient's skin and through which the insulin is infused. Infusion pump therapy offers the advantages of continuous insulin infusion, precise dosing, and programmable delivery schedules.

[0004] Anomalies or faults, such as leaks, blockages, or the presence of air bubbles in the fluid pathway, can occur within an infusion pump and not necessarily be noticeable to the user. Detecting a fault, such as a partial or complete blockage along the fluid pathway within the infusion pump, can be desirable to maintain precisely controlled drug delivery and advise the user to discontinue use of the malfunctioning infusion device. A common solution to blockage detection is to place a pressure sensor within the infusion pump system and report a blockage when the pressure exceeds a certain threshold. However, adding a pressure sensor increases system complexity (e.g., increasing mechanical complexity, electrical complexity, and / or software complexity), increases system power consumption, and increases the cost of the infusion pump.

[0005] For medical devices such as wearable drug delivery pumps, where some or all of the components are disposable for ease of use and cost effectiveness, it is undesirable to add another component, such as a pressure sensor, and the associated increased cost and complexity to the medical device. Thus, a need exists for accurate occlusion detection without adding infusion pump components, thereby increasing infusion pump complexity and cost. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] International Publication No. 2015 / 157174 Brochure Summary of the Invention [Means for solving the problem]

[0007] The above-mentioned problems and other problems are overcome, and additional advantages are realized, by exemplary embodiments of the present invention.

[0008] It is an aspect of an exemplary embodiment to provide an infusion device with integrated occlusion sensing, comprising: a pump including a chamber configured with at least one port for receiving fluid from a reservoir into the chamber and through which the fluid flows out of the chamber; and a pumping mechanism configured to control the intake of a predetermined amount of fluid into the chamber during an aspiration stroke and the dispensing of a predetermined amount of fluid from the chamber during a dispense stroke; a pump measurement device configured to generate pump measurements of at least one of each aspiration stroke performed by the pump and each dispense stroke performed by the pump; and a processing device configured to analyze the pump measurements, including pump measurements for each of a plurality of the at least one of the aspiration strokes and the dispense strokes, and to determine when the pump measurements include a plurality of pump measurements that satisfy a predetermined metric designated as an indicator of occlusion.

[0009] According to aspects of the exemplary embodiment, the infusion pump with integrated occlusion sensing further comprises an indicator, and the processing device is configured to operate the indicator as an occlusion alert in response to determining that the plurality of pump measurements satisfy a predetermined metric.

[0010] According to aspects of the exemplary embodiment, the processing device is configured to automatically terminate operation of the pumping mechanism in response to determining that the plurality of pump measurements satisfy a predetermined metric.

[0011] According to aspects of an exemplary embodiment, the pump measurements correspond to the duration of at least one of an aspiration stroke and a dispense stroke, and the predetermined metric is a selected duration that is shorter than the average value of the pump measurements when no blockage occurs in the pump.

[0012] According to an aspect of the exemplary embodiment, the pump measurement device is an end-stop switch on the pump configured to be activated when the pumping mechanism completes at least one of an aspiration stroke and a dispense stroke, and the end-stop switch is connected to the processing device to determine the duration of each of the at least one of the aspiration stroke and the dispense stroke.

[0013] According to aspects of the exemplary embodiment, the pump measurements correspond to the duration of endstop switch actuation, and the predetermined metric is a selected duration for endstop switch actuation that is longer than the average value of the pump measurements when no blockage occurs in the pump.

[0014] According to aspects of the exemplary embodiment, the pump measurements include at least two of the endstop switch actuation duration, the duration of at least one of the aspiration stroke and the dispense stroke, and the time difference between the aspiration stroke and the dispense stroke. The predefined metric corresponding to the stroke duration is a selected duration that is shorter than the average value of the stroke duration when no occlusion occurs in the pump. The predefined metric corresponding to the dispense stroke duration difference relative to the aspiration stroke duration is a selected duration that is greater than the average value of the stroke duration difference when no occlusion occurs in the pump. The processing device is configured to analyze the pump measurements, including determining when the pump measurements include a plurality of pump measurements that satisfy corresponding ones of the predefined metrics.

[0015] According to aspects of exemplary embodiments, the pump measurements correspond to a time difference between an aspiration stroke and a dispense stroke, and a predefined metric corresponding to a dispense stroke duration difference relative to an aspiration stroke duration is a selected duration that is greater than an average value of the stroke duration difference when no occlusion occurs in the pump. According to aspects of exemplary embodiments of the present invention, the pump measurements may also include a duration of at least one of the aspiration stroke and the dispense stroke, and the predefined metric corresponding to the stroke duration is a selected duration that is less than an average value of the stroke duration when no occlusion occurs in the pump. The processing device is configured to analyze the pump measurements and determine when the pump measurements include a plurality of pump measurements that satisfy a corresponding one of the predefined metrics.

[0016] It is an aspect of an exemplary embodiment to provide a method of occlusion sensing in an infusion pump comprising: operating a pump comprising a chamber configured with at least one port for receiving fluid from a reservoir into the chamber and through which the fluid flows out of the chamber; and a pumping mechanism configured to control the intake of a predetermined amount of fluid into the chamber during an aspiration stroke and to control the dispensing of a predetermined amount of fluid from the chamber during a dispense stroke; operating a pump measurement device to generate pump measurements of at least one of each aspiration stroke performed by the pump and each dispense stroke performed by the pump; and analyzing the pump measurements, including the pump measurements for each of a plurality of the at least one of the aspiration strokes and the dispense strokes, to determine when the pump measurements include a plurality of pump measurements that satisfy a predetermined metric designated as an indicator of occlusion.

[0017] According to aspects of the exemplary embodiment, the method of occlusion sensing further includes activating an indicator occlusion alert in response to determining that the plurality of pump measurements satisfy a predetermined metric.

[0018] In accordance with aspects of the exemplary embodiment, the method of occlusion sensing further includes automatically terminating operation of the pumping mechanism in response to determining that the plurality of pump measurements satisfy a predetermined metric.

[0019] According to aspects of the exemplary embodiment, the method of occlusion sensing further includes operating the pump measurement device to generate a pump measurement corresponding to a duration of at least one of an aspiration stroke and a dispense stroke. For example, the method of occlusion sensing can use a predefined metric as a selected duration that is shorter than an average value of the pump measurements when no occlusion occurs in the pump.

[0020] According to aspects of the exemplary embodiment, the method of occlusion sensing further includes configuring the pump measurement device as an end-stop switch on the pump that is activated when the pumping mechanism completes at least one of an aspiration stroke and a dispense stroke, and connecting the end-stop switch to a processing device configured to analyze signals from the end-stop switch to determine a duration of each of the at least one of the aspiration stroke and the dispense stroke.

[0021] According to aspects of the exemplary embodiment, the pump measurements correspond to the duration of endstop switch actuation, and the predetermined metric is a selected duration for endstop switch actuation that is longer than the average value of the pump measurements when no blockage occurs in the pump.

[0022] According to aspects of an exemplary embodiment, the pump measurements include at least two of an endstop switch actuation duration, a duration of at least one of an aspiration stroke and a dispense stroke, and a time difference between an aspiration stroke and a dispense stroke. The predetermined metric corresponding to the stroke duration is a selected duration that is shorter than an average value of the stroke duration when no occlusion occurs in the pump, and the predetermined metric corresponding to the dispense stroke duration difference relative to the aspiration stroke duration is a selected duration that is greater than an average value of the stroke duration difference when no occlusion occurs in the pump. Analyzing the pump measurements includes determining when the pump measurements include a plurality of pump measurements that satisfy corresponding ones of the predetermined metrics.

[0023] According to aspects of an exemplary embodiment, the pump measurements correspond to a time difference between an aspiration stroke and a dispense stroke, and a predetermined metric corresponding to a difference in dispense stroke duration relative to an aspiration stroke duration is a selected duration that is greater than an average value of the stroke duration difference when no occlusion occurs in the pump. The pump measurements can also include a duration of at least one of the aspiration stroke and the dispense stroke, and the predetermined metric corresponding to the stroke duration is a selected duration that is less than an average value of the stroke duration when no occlusion occurs in the pump. Analyzing the pump measurements includes determining when the pump measurements include a plurality of pump measurements that satisfy a corresponding one of the predetermined metrics.

[0024] Additional and / or other aspects and advantages of the invention will be set forth in or will be apparent from the description that follows, or may be learned by practice of the invention. The invention may comprise a device and a method for operating the same having one or more of the above-described aspects and / or one or more of the features, and combinations thereof. The invention may, for example, comprise one or more of the features and / or combinations of the above-described aspects as set forth in the appended claims. [Brief explanation of the drawings]

[0025] The above and / or other aspects and advantages of embodiments of the present invention will be more readily appreciated from the following detailed description taken in conjunction with the accompanying drawings.

[0026] [Figure 1] 1 is a partial perspective view of exemplary pump components within an exemplary drug delivery device operating according to an occlusion detection algorithm in accordance with an exemplary embodiment. [Figure 2] 1 is a partial perspective view of exemplary pump components within an exemplary drug delivery device operating according to an occlusion detection algorithm in accordance with an exemplary embodiment. [Figure 3A] 3 is a perspective view of the pump components of FIGS. 1 and 2 in an exemplary drug delivery device arranged according to a ready-to-dispense stage of operation. FIG. [Figure 3B] 3 is a perspective view of the pump components of FIGS. 1 and 2 in an exemplary drug delivery device arranged according to a ready-to-suck stage of operation. FIG. [Figure 3C] FIG. 3 is a perspective view of components within an exemplary drug delivery device comprising the exemplary pump components of FIGS. 1 and 2 and associated electronic circuitry on a printed circuit board. [Figure 4] FIG. 1 is a block diagram of components within an exemplary drug delivery device. [Figure 5A] FIG. 10 illustrates pump duration times for multiple aspiration strokes of an exemplary drug delivery device under normal operating conditions. [Figure 5B] FIG. 10 illustrates pump duration times for multiple dispense operations of an exemplary drug delivery device under normal operating conditions. [Figure 6A] FIG. 5C shows pump duration times for multiple aspiration strokes of the same type of drug delivery device used to generate FIGS. 5A and 5B but under occluded operating conditions. [Figure 6B]FIG. 5C illustrates pump duration times for multiple dispensing operations of the same type of drug delivery device used to generate FIGS. 5A and 5B but under occluded operating conditions. [Figure 7] 10 is a flow diagram of an example operation of an example drug delivery device operating according to an occlusion detection algorithm using a stroke duration criterion according to an example embodiment. [Figure 8A] 1 is a graph illustrating exemplary endstop or limit switch actuation data during normal operation of an exemplary pump. [Figure 8B] 10 is a graph illustrating exemplary endstop or limit switch actuation data during occluded operation of an exemplary pump. [Figure 9] 10 is a flow diagram of an example operation of an example drug delivery device operating according to an occlusion detection algorithm using an endstop or limit switch actuation duration criterion according to an example embodiment. [Figure 10] 10 is a graph showing exemplary pump measurement data illustrating short dispense stalk durations (e.g., when the pump piston cannot move during an occlusion). [Figure 11] 10 is a graph illustrating exemplary pump measurement data showing extended endstop or limit switch activation duration (e.g., when an occlusion causes pumping back into the pump reservoir). [Figure 12A] 10 is a graph showing pump measurement data from each pump showing long dispense stroke duration (e.g., when leakage occurs due to an occlusion) versus aspiration stroke duration. [Figure 12B] 10 is a graph showing pump measurement data from each pump showing long dispense stroke duration (e.g., when leakage occurs due to an occlusion) versus aspiration stroke duration. [Figure 12C] 10 is a graph showing pump measurement data from each pump showing long dispense stroke duration (e.g., when leakage occurs due to an occlusion) versus aspiration stroke duration. [Figure 12D]10 is a graph showing pump measurement data from each pump showing long dispense stroke duration (e.g., when leakage occurs due to an occlusion) versus aspiration stroke duration. [Figure 13] 10 is a flow diagram of an example operation of an example drug delivery device operating in accordance with occlusion detection using leak detection criteria in accordance with an example embodiment. [Figure 14] 10 is a flow diagram of an example operation of an example drug delivery device operating according to an occlusion detection algorithm using a combination of criteria in accordance with an example embodiment.

[0027] Throughout the drawing figures, like reference numerals will be understood to refer to like elements, features, and structures. DETAILED DESCRIPTION OF THE INVENTION

[0028] Reference will now be made in detail to the exemplary embodiments of the invention, which are illustrated in the accompanying drawings, in which the exemplary embodiments described herein illustrate, but do not limit, the invention.

[0029] Exemplary embodiments can be used with any type of infusion pump that functions on the principle of filling a chamber (e.g., with liquid drug from a reservoir) in one stage and then draining fluid from the chamber (e.g., into a delivery device such as a cannula deployed in a patient) in another stage. For example, a reciprocating plunger-type pump or a rotary metering-type pump can be used. In either case, the piston or plunger is retracted from the chamber to aspirate or draw drug into the chamber and allow the chamber to fill with a predetermined amount of drug (e.g., from a drug reservoir or cartridge into an inlet port). The piston or plunger is then reinserted into the chamber to dispense or expel the predetermined amount of drug from the chamber (e.g., via an outlet port) into a fluid path extending between the pump and a cannula in the patient.

[0030] For illustrative purposes, reference is made to the rotary metering-type pump described in commonly owned U.S. Patent Application Publication No. 2009 / 012999, the contents of which are incorporated herein by reference in their entirety. Referring to Figures 1, 2, 3A, 3B, and 3C, an exemplary infusion pump (e.g., a wearable drug delivery device such as an insulin patch pump) includes a pump assembly 20 connectable to a DC motor and gearbox assembly (not shown) for rotating a sleeve 24 within a pump manifold 22. A helical groove 26 is provided on the sleeve. A coupling pin 28 connected to a piston 30 translates along the helical groove to guide the retraction and insertion of the piston 30 within the sleeve 24 as the sleeve 24 rotates in one direction and then the other. The sleeve has an end plug 34. Two seals 32, 36 on each end of the piston and end plug inside sleeve 24 define a cavity or chamber 38 when piston 30 is retracted following a suction stroke and thus ready to dispense, as shown in FIG. 3A. The volume of chamber 38 therefore varies depending on the degree of retraction of piston 30. As shown in FIG. 3B, when piston 30 is fully inserted and seals 32, 36 are in substantial contact with one another and thus ready to aspirate, the volume of chamber 38 is negligible or essentially zero. Two ports 44, 46 are provided to pump manifold 22, including an inlet port 44 through which drug can flow from a reservoir 70 (FIG. 4) for pump 64 (FIG. 4), and an outlet port 46 through which drug drawn into chamber 38 (e.g., by retraction of piston 30 during the suction stage of operation) can be dispensed from chamber 38, e.g., from a fluid path to a cannula 72 (FIG. 4) within the patient, upon reinsertion of piston 30 into chamber 38.

[0031] 1, 2, 3A, 3B, and 3C, the sleeve 24 may include an aperture (not shown) that aligns with the outlet port 46 or the inlet port 44 to allow flow of drug in the chamber 38 through a corresponding one of the ports 44, 46 (i.e., depending on the degree of rotation of the sleeve 24 and therefore the degree of translation of the piston 30). For example, a pump metering device 78 (FIG. 4) such as a sleeve rotary limit switch may be provided having an interlock 42 and one or more detents 40 on the sleeve 24 or its end plug 34 that cooperate with the interlock 42. The interlock 42 may be attached to the manifold 22 at each end thereof. When the pump 64 is in a first position whereby the side hole in the sleeve 24 is aligned with the inlet port 44 to receive fluid from the reservoir 70 into the chamber 38, the detents 40 on the end face of the sleeve 24 abut the ridges 48 of the interlock 42. Under certain conditions, such as back pressure, it is possible that friction between the piston 30 and sleeve 24 may be sufficient to rotate the sleeve 24 before the piston 30 and coupling pin 28 reach both ends of the spiral groove 26. This can result in an incomplete amount of liquid being pumped with each stroke. To prevent this situation, the interlock 42 prevents the sleeve 24 from rotating until the torque passes a predetermined threshold, as shown in FIG. 3A. This ensures that the piston 30 rotates fully within the sleeve until the coupling pin reaches the end of the spiral groove 26. Once the coupling pin 28 hits the end of the spiral groove 26, further movement by a DC motor and gearbox assembly or other type of pump and valve actuator 66 (FIG. 4) increases the torque on the sleeve 24 beyond the threshold, bending the interlock 42 and forcing the detent 40 past the ridge 48. Upon completion of rotation of sleeve 24 such that its side hole is oriented with cannula 72 or exit port 46, detent 40 moves over ridge 48 in interlock 42, as shown in Figure 3B.Another sleeve feature may be provided for engaging an electrical switch (e.g., an end stop switch 90 provided on a printed circuit board 92 and disposed relative to the sleeve and / or end plug 34 to cooperate with the pump measurement device 78, as shown in FIG. 3C).

[0032] FIG. 4 is an exemplary system diagram showing exemplary components within an exemplary drug delivery device 10 having an infusion pump, such as the pumps of FIGS. 1, 2, 3A, 3B, and 3C. The drug delivery device 10 can include an electronics subsystem 52 for controlling the operation of components within the fluidics subsystem 54, such as a pump 64 and an insertion mechanism 74 for deploying a cannula 72 for insertion into an infusion site on a patient's skin. The power storage subsystem 50 can include, for example, a battery 56 for providing power to the components within the electronics subsystem 52 and the fluidics subsystem 54. The fluidics subsystem 54 can include, for example, an optional fill port 68 for filling a reservoir 70 (e.g., with a drug), although the drug delivery device 10 can optionally be shipped from manufacture with its reservoir already filled. The fluidics subsystem 54 also has a metering subsystem 62 comprising a pump 64 and a pump actuator 66. As explained above, the pump 64 may have two ports 44, 46 and associated valve subassemblies that control when fluid enters and leaves the pump chamber 38 through the respective ports 44, 46. One of the ports is the inlet port 44 through which fluid, such as a liquid medication, flows from a reservoir 70 into the pump 64 as a result of a pump suction or pull stroke on the pump plunger or piston 30. The other port is the outlet port 46 through which fluid flows from the pump chamber 38 toward the cannula 72 for administration to the patient as a result of a pump ejection or push stroke on the pump plunger or piston 30. The pump actuator 66 may be a DC motor and gearbox assembly or other pump drive mechanism for controlling the plunger or piston 30 and other associated pump components, such as the sleeve 24, which may rotate relative to the translational movement of the pump piston 30.Microcontroller 58 can include an integrated or separate memory device with computer software instructions for actuating, for example, rotation of sleeve 24 in a selected direction, translational or axial movement of piston 30 within sleeve 24 for aspiration or dispense strokes, and, optionally, rotation of sleeve 24 and piston 30 together during valve state changes, as described in the above-referenced '666 patent. As described below, an occlusion detection algorithm according to an exemplary embodiment can be provided to microcontroller 58 to monitor pump measurements and detect when an occlusion operating condition occurs for the infusion pump.

[0033] Regardless of the type of pump mechanism 64 used to aspirate and dispense a controlled amount of drug into and from the pump chamber 38, the pump 64 has associated with it an expected pump duration for one or both of the aspirate and dispense stages or strokes that can be attributed to pump characteristics. For example, in the exemplary pump assembly 20 shown in Figures 1, 2, 3A, 3B, and 3C, the pump duration for aspirating drug into and dispensing drug from the chamber 38 is affected by pump characteristics such as the internal volume of the pump chamber 38, the length or distance of the pump piston stroke, the characteristics of the port seals provided at the inlet and output ports 44, 46, etc. When the pump pressure is within a specified relative normal range for operation, the pump duration to fill chamber 38 with a specified amount of fluid (e.g., a desired dose) and expel the specified amount of fluid from the chamber can be determined and used as a baseline for monitoring pump 64 under normal operating conditions to determine when an abnormal operating condition occurs, such as due to leakage of fluid from the pump chamber or an occlusion in the pump fluid path whereby the specified amount of fluid (e.g., a desired dose) cannot be delivered from the chamber via a dispense stroke, in either scenario. This can be undesirable because the patient would not receive the desired dose.

[0034] As mentioned above, a common solution for occlusion detection is to place an additional pressure sensor within the pump control system and report an occlusion when the pressure exceeds a certain threshold. However, adding a pressure sensor has the disadvantage of increasing system complexity (e.g., mechanical complexity, electrical complexity, and / or software complexity), increasing system power consumption, and / or increasing pump costs. These disadvantages may be particularly disadvantageous for wearable pump designs where all or part of the pump is intended to be disposable once the reservoir 70 is emptied or the pump 64 has been used for a selected amount of time and / or to deliver a selected amount of medication.

[0035] According to an exemplary embodiment, occlusion detection is achieved without additional components, such as occlusion sensors, deployed upstream or downstream of pump 64. When microcontroller 58 or other processing device for controlling pump operation already performs pump duration measurements for normal operation, such as for one or both of the aspiration and dispense strokes, microcontroller 58 is further controllable to determine when the pump duration measurements fall outside a specified range for normal operating conditions, thus indicating an occlusion, and generate an indication of the detected occlusion. Thus, pump 64 and / or the entire drug delivery device 10 can then be replaced or repaired, thereby ensuring that the patient is receiving the full intended dose provided under normal operating conditions.

[0036] When pump duration measurements are implemented for pump operation, occlusion detection can be achieved by adding operations such as monitoring pump duration and determining when a specified pump duration threshold or other criteria for normal pump operation conditions is not met to the computer software instructions of the microcontroller 58, or a remote device controlling the drug delivery device 10. Thus, occlusion detection is implemented via a software solution, and no hardware modifications to the pump are required. As explained below, a clear difference in pump duration exists between a normal pump and an occluded pump. Therefore, false alarm and error rates are extremely low. Thus, an occlusion detection algorithm configured according to aspects of an exemplary embodiment can provide reliable occlusion detection results.

[0037] Determining a pump duration threshold or range of values ​​or other metrics indicative of blockage can be performed empirically, for example, for a selected type of pump 64. Metrics for a selected type of pump experiencing normal operating pressure can be compared to metrics for the same type of pump except it is experiencing at least partial or complete blockage. For example, a blockage in the downstream path from a blocked pump 64 to its cannula 72 will increase pressure in the pump's 64 fluid path over time. When the pressure in the blocked pump exceeds a threshold, the blocked pump will eventually begin to leak. Log files of normal and blocked pumps can be generated to capture their respective pump duration information for aspirate and / or dispense strokes. However, it should be understood that different pump measurements other than pump duration (i.e., the duration of an aspirate or dispense stroke) can be used to determine differences in pump operation during normal and blocked operating conditions, as well as to determine thresholds for monitoring pump operation and distinguishing between normal and blocked operating conditions. For example, as described below, the termination of a long stroke switch activation or a significant difference in the respective durations of the aspirate and dispense strokes can be used to detect the occurrence of an occlusion.

[0038] 5A and 5B, the pumping duration of the pump experiencing an occlusion (e.g., approximately 1.5 seconds on average) is significantly shorter than the pumping duration of pump 64 when it is operating under normal conditions (e.g., on the order of 3 to 3.5 seconds). The phenomenon of shorter pumping duration is related to the pumping mechanisms, such as piston 30, sleeve 24, interlock 42, and silicone seals on inlet and outlet ports 44, 46, described above in connection with FIGS. 1, 2, 3A, 3B, and 3C. As described above, different types of pumps 64 can be improved by implementing occlusion sensing according to exemplary embodiments, and different pump components can contribute to shortened pumping during an occlusion condition. Pump 64 can be a rotary metering or reciprocating type pump, or other type of pump that draws or aspirates fluid from an upstream reservoir and then expels or dispenses the fluid into a separate downstream fluid path leading to the patient.

[0039] Referring to the exemplary infusion pump 64 described above in connection with FIGS. 1, 2, 3A, 3B, and 3C, the pump's aspiration and dispensing strokes, driven by the translation of piston 30 within outer plastic sleeve 24, are associated with switching pump 64 between upstream and downstream fluid paths. As piston 30 is rotated (e.g., by a DC motor and gearbox assembly, not shown), piston 30 translates through sleeve 24 guided by the progression of pin 28 on the piston through helical slot 26 in sleeve 24. Once piston 30 has fully translated through sleeve 24 and completed its aspiration or dispensing stage of fluid, it engages sleeve 24 directly via pin 28 in slot 26, coupling the rotation of piston 30 and sleeve 24. This allows sleeve 24 to rotate between the upstream and downstream fluid paths and activate the end of a stroke electrical switch 90 or other component associated with pump measurement device 78 (FIG. 4) and provided on pump 64 and / or within drug delivery device 10. During normal operation, the presence of interlock 42 prevents piston 30 and sleeve 24 rotation from coupling before piston 30 completes its translation through sleeve 24. However, if pressure in the downstream fluid path increases above a threshold, piston 30 and sleeve 24 rotation will couple, allowing sleeve 24 to pass under interlock 42 and activate switch 90 (e.g., via sleeve feature 41 associated with pump measurement device 78) before piston 30 completes its translation through the sleeve. This significantly reduces pump duration (e.g., from between 3 and 3.5 seconds during normal conditions to less than 2 seconds during occluded conditions).

[0040] Reference is now made to Figures 6A and 6B, which show pump duration data from several similar type pumps 64 over several pump cycles. For example, log data from 19 pumps that completed 600 complete cycles are shown, with 10 of the pumps operating under normal conditions and 9 of the pumps operating under blocked conditions. It can be seen from Figures 6A and 6B that all of the blocked pumps had sections with pump durations of less than 2 seconds. Some pump durations returned to normal, which may be due to a release of pressure from leaking in the manifold area. The apparent difference in pump duration between normally operating pumps and pumps that experienced blockages allows for the use of blockage detection algorithms based on pump duration.

[0041] Referring to FIG. 7 , an exemplary occlusion detection process includes setting a pump measurement threshold or metric, such as a stroke duration threshold (block 80), where a stroke duration above the threshold indicates normal pump operation and a stroke duration below the threshold indicates an occlusion. To set the threshold, pump measurement data is analyzed. For example, aspiration stroke duration and dispense stroke duration can be detected by limit switches or other pump measurement devices 78 ( FIG. 4 ) provided with the pump. In the exemplary pump described with reference to FIGS. 1 , 2 , 3A , 3B , and 3C , stroke or pump duration is determined using sleeve rotation limit switches or other pump measurement devices 78. For example, microcontroller 58 and other electronic components, such as end-stop switch 90 cooperating with sleeve feature 41, can be deployed on a printed circuit board (PCB) 92 typically associated with pump 64 or delivery device 10. End-stop switch actuation data can be collected and stored (e.g., via a memory device integrated with microcontroller 58 or implemented as a separate component on PCB 92). Microcontroller 58 may include an occlusion detection algorithm for processing the endstop switch actuation data to determine if an occlusion has occurred. According to another exemplary embodiment, the endstop switch actuation data can be provided (e.g., wirelessly or via a wireline connection) from pump 64 to another device having an occlusion detection algorithm, such as a handheld remote controller for pump 64 or a non-dedicated computing device (e.g., a mobile phone, personal computer (PC), laptop computing device, or other portable computing device) that includes software or an app that includes the occlusion detection algorithm.

[0042] Pump measurement data is obtained for one or more pumps of the same type operating under normal conditions and for one or more pumps of the same type operating under obstructed conditions, as shown above in FIGS. 5A and 5B and 6A and 6B. The pump measurement data for these two groups of pumps can be averaged, summarized, or categorized and then analyzed to determine the degree of difference between the pump measurements for the normally operating pump and the obstructed pump. A threshold or other metric can be determined to be above and / or below a value or range of values ​​within a margin that does not include normal pump measurements. The value or range of values ​​and / or margin can be specified by a user or automatically determined based on the pump measurement data obtained from the pump. As described above, the pump measurement data is generated and monitored during the course of normal pump activity and, therefore, does not require additional components that increase the complexity of the pump, rather than added operations.

[0043] 7, once the pump measurement metric (e.g., stroke duration threshold) is set, the microcontroller 58 within the drug delivery device 10 is controlled by the occlusion detection algorithm to obtain pump measurement data (e.g., stroke duration data) for the pump (block 81) and compare the stroke duration data to the pump measurement metric during various pump stages or cycles of operation, such as for each pump cycle (block 82). If the stroke duration data meets the pump measurement metric (e.g., a Th of 2 seconds for pump 64), the microcontroller 58 determines whether the pump measurement metric is met. stroke If the stroke duration data fails to meet a pump measurement metric (e.g., falls below an occlusion detection threshold (e.g., a Th of 2 seconds for pump 64), the pump is determined to be operating normally (block 84). stroke When the counter is greater than the threshold for normal operation, Thstroke is not met, the counter is incremented (block 83). Referring to block 85, the counter is incremented to a selected value (e.g., a threshold Th for normal operation). stroke An occlusion is detected when the counter reaches a counter value of 8 (corresponding to 8 pump cycles where ≠ 0 is not met). The total number of cycles reached before the selected number of cycles is indicated as occlusion can be specified, such as 8 consecutive cycles or within a specified number of cycles (e.g., 20 cycles). The microcontroller 58 can be configured by the occlusion detection algorithm to generate an optional indication of a detected occlusion error (block 86), automatically cease operation of the pump and / or drug delivery device 10, and / or generate an optional indication to the user to cease using the pump (block 88). If the selected counter value has not yet been reached after the counter is incremented per block 83, pump measurement data continues to be collected per block 81. Because the occlusion detection algorithm is based on pump duration or other pump measurement data already performed in the pump, occlusion detection is achieved by checking the pump duration or other measurement data in software against a selected threshold or metric. Thus, a software-only solution is provided for detected occlusion, obviating the need for hardware modifications.

[0044] The exemplary pump 64 described in connection with Figures 1, 2, 3A, 3B, and 3C uses one or more on / off limit switches to determine the state of the system at the limits of rotational travel. For example, a multi-stage pump (i.e., a pump that aspirates fluid to fill a chamber during one stage and then discharges the pump chamber in the next stage) may use some type of end-stop switch for each stage to detect when the piston and / or sleeve or other pump component reaches a predetermined position corresponding to the full aspiration or dispense position. However, it should be understood that different mechanisms or other pump measurement devices 78 can be used to determine pump measurements (e.g., pump duration) other than the interlock 42 and sleeve rotation limit switch (e.g., end-stop switch) 90. Alternatively, the pump 64 may use one or more optical sensors or encoders with optical switches to determine the position of the pump components at their respective end-stop positions for full aspiration and / or dispense.

[0045] Thus, with reference to FIG. 7 and in accordance with an exemplary embodiment of the present invention, as described, a determination of the time required to fill the chamber and the time required to expel a desired amount of fluid from the chamber is performed, the expulsion time of at least each stroke is measured, and further, when a selected number of expulsion times fail to exceed a specified amount (e.g., stroke duration shortens over a specified number of pump cycles), an indicator is generated to indicate that an occlusion has been detected.

[0046] According to another exemplary embodiment, occlusion detection is performed by monitoring the duration of actuation or triggering of a pump endstop or limit switch, as described below with reference to Figure 9. Processing monitored data related to the detected duration of actuation or triggering of a pump endstop or limit switch to determine whether an occlusion in pump 64 has occurred can be performed alone or in combination with monitoring for short pump stroke durations, as described above with reference to Figure 7.

[0047] As explained above, during normal operation, the presence of interlock 42 prevents piston 30 and sleeve 24 rotation from coupling before piston 30 completes its translation through sleeve 24. However, when pressure in the downstream fluid path increases (i.e., during occlusion), piston 30 and sleeve 24 rotation can couple prematurely. That is, sleeve 24 rotates prematurely before its intended rotation during a valve state change—for example, when sleeve 24 rotates without axial motion at the end of a full piston stroke to align its side ports with corresponding ones of ports 44, 46 during normal pump operation. This premature rotational coupling of piston 30 and sleeve 24 then allows sleeve 24 to pass under interlock 42 and trigger switch 78 before piston 30 completes its axial translation through the sleeve. This significantly reduces pump duration (e.g., measured as the time period or duration between pump motor activation and endstop switch signal), as explained above in connection with FIG. 7 . Additionally, another pump operating characteristic that can be monitored for occlusion detection is the duration that the pump measurement device 78 and its associated switch 90 are in an actuated or triggered mode of operation or indicate the beginning of an actuated state.

[0048] In some instances, pump duration in an occluded pump system can remain normal and fail to decrease as expected. Therefore, monitoring another pump measurement parameter or characteristic increases occlusion detection accuracy. For example, while the pump sleeve 24 rotates early as expected due to an occlusion in the pump system, the piston can begin to advance and dispense a fluid payload into the upstream fluid path as soon as the pump sleeve opens to the upstream fluid path (and before the end-of-stroke signal from the switch 90). Because both the piston 30 and the sleeve 24 can rotate through their full range of angular positions, the total pump operation time remains constant both with and without an occlusion. Meanwhile, now that the piston 30 is rotating and translating through the sleeve 24 after the sleeve has rotated on the upstream channel, the end-stop switch 90 has now been triggered for an extended period of time. Therefore, occlusion detection can include monitoring for or triggering a long or extended end-stop of limit switch actuation, separately from or in addition to monitoring for shortened pump stroke duration according to exemplary embodiments.

[0049] To further illustrate how actuation or triggering of the pump measurement device may be delayed as a result of an occlusion, reference is made to an exemplary pump 64 described by the exemplary embodiment shown in Figures 1, 2, 3A, 3B, and 3C. During normal pump 64 operation, when end stop switch 90 is initially struck, dragged, and thus triggered by pump sleeve 24 (e.g., via sleeve feature 41 engaging end stop switch 90), end stop switch 90 causes a drop in its end stop switch voltage signal from 1.8V to 0V, which is provided to microcontroller 58. Only when switch 90 is released (e.g., by disengaging sleeve feature 41) and springs back to center does it return the end stop switch voltage to 1.8V. In some examples, when the side port of sleeve 24 opens to the upstream fluid pathway (e.g., aligned with input port 44), before piston 30 completes its axial translation and before endstop switch 90 is disengaged by sleeve feature 41, and when pressure in the upstream fluid pathway is low, piston 30 can begin to advance and translate through sleeve 24, draining the pump contents into the upstream fluid pathway while endstop switch 90 is in the intermediate trigger state. The net result is an endstop switch 90 actuation signal (e.g., a voltage drop) for an extended period of time. This pump occlusion characteristic is illustrated in FIGS. 8A and 8B, which show a typical duration of switch 90 actuation (e.g., 0 volts) of less than 0.5 seconds and an extended endstop or limit switch 90 actuation (e.g., 0 volts) of approximately 1.5 seconds, respectively.

[0050] There are several reasons why some pumps 64 may exhibit a shorter overall pump duration (e.g., failure of piston 30 to advance), while some pumps 64 may exhibit an increased end-stop switch 90 actuation signal duration (e.g., as piston 30 advances on the upstream fluid path). For example, alignment of switch 90 on PCB 92 with associated pump components (e.g., interlock 42, detents 40, and sleeve features 41) may allow some variability in which sleeve angular position releases end-stop switch 90 and therefore when the end-stop switch actuation signal is generated and provided to microcontroller 58. Additionally, high pressure in the upstream fluid path from a larger insulin reservoir fill volume may prevent piston 30 from advancing on the upstream fluid path (e.g., resulting in a shorter pump duration), while lower pressure in the upstream fluid path from a lower insulin reservoir fill volume may allow piston 30 to advance on the upstream fluid path (e.g., resulting in a longer or extended end-stop or limit switch actuation or “trigger” duration).

[0051] 9 , an exemplary occlusion detection process includes setting a pump measurement threshold or metric (block 96), such as a switch actuation duration threshold, where a switch actuation duration below the threshold indicates normal pump operation and a switch actuation duration above the threshold indicates an occlusion. To set the threshold, pump measurement data can be analyzed. For example, several identical pumps 64 can be tested with similar occlusion conditions to collect pump measurement data related to an indicated significant increase in the duration of a pump measurement parameter, such as an end-stop switch signal voltage drop, when the pump is occluded. In the case of exemplary empirical measurements for the pump 64 in FIGS. 1 , 2 , 3A, 3B, and 3C , the switch actuation duration during occlusion was measured to be approximately 1.5 seconds, which corresponds to the expected amount of time for the piston 30 to fully translate through the sleeve 24. Thus, the occlusion detection algorithm logs the end-stop switch 90 signal duration according to software instructions (e.g., within the microcontroller 58) and compares the logged switch 90 actuation duration to a threshold (e.g., Th switch>1.0 seconds) to determine whether an occlusion is present or absent, as shown within block 98 of FIG. 9 . Endstop switch actuation data or pump limit switch actuation data can be collected and stored (e.g., via a memory device integrated with microcontroller 58 or implemented as a separate component on PCB 92). Microcontroller 58 can include an occlusion detection algorithm for processing the endstop switch actuation data to determine whether an occlusion has occurred. According to another exemplary embodiment, endstop switch actuation data can be provided (e.g., wirelessly or via a wireline connection) from pump 64 to another device having an occlusion detection algorithm, such as a handheld remote controller for pump 64 or a non-dedicated computing device (e.g., a mobile phone, personal computer (PC), laptop computing device, or other portable computing device) that includes software or an app that includes an occlusion sensing algorithm. Switch actuation duration data for an occluded pump can be averaged or summarized or categorized and then analyzed to determine the degree of difference between similar pump measurements for a normally operating pump and the pump measurements for the occluded pump. A threshold (e.g., Th switch , ) or other metrics are determined to be above and / or below a value or range of values ​​within a margin that normal pump measurements do not fall within. The value or range of values ​​and / or margins can be specified by a user or can be determined automatically based on pump measurement data obtained from the pump. As discussed above, pump measurement data such as switch actuation duration is generated and monitored during the course of normal pump activity and, therefore, does not require additional components that increase the complexity of the pump.

[0052] 9 , once the pump measurement metric (e.g., switch actuation duration threshold) is set, the microcontroller 58 within the drug delivery device 10 is controlled by the occlusion detection algorithm to obtain pump measurement data (e.g., switch actuation duration data) for the pump 64 (block 97) and compare the switch actuation duration data with the pump measurement metric during various pump stages or cycles of operation, such as for each pump cycle (block 98). switch If the switch actuation duration data fails to meet the pump measurement metric (e.g., an occlusion detection threshold Th of 1.0 seconds), the pump is determined to be operating normally (block 100). switch When the counter is greater than the threshold Th for normal operation, the pump is determined to be experiencing a blockage condition. switch is not met, it is incremented (block 99). Referring to block 101, the counter is set to a selected value (e.g., Th for normal operation). switchAn occlusion is then detected when the counter reaches a counter value of 8 (corresponding to 8 pump cycles where ≠ 0 is not met). The total number of cycles reached before an occlusion is indicated can be specified, such as 8 consecutive cycles or within a specified number of cycles (e.g., 20 cycles). The microcontroller 58 can be configured by the occlusion detection algorithm to generate an optional indication of a detected occlusion error (block 102), automatically cease operation of the pump 64 and / or drug delivery device 10, and / or generate an optional indication to the user to cease using the drug delivery device 10 (block 104). If the selected counter value has not yet been reached after the counter is incremented per block 99, pump measurement data continues to be collected per block 97. Because the occlusion detection algorithm is based on pump duration data or other pump measurement data already implemented in the pump, occlusion detection is achieved by checking the pump duration or other measurement data in software against a selected threshold or metric. Thus, a software-only solution is provided for detected occlusion, obviating the need for hardware modifications.

[0053] According to another exemplary embodiment of the present invention, a third pump characteristic is monitored to detect blockages in the drug delivery device 10, as described below in connection with FIG. 13 . For example, testing a selected pump 64 under blockage conditions revealed that if blockages occurred when the drug delivery device 10 was new, the pump 64 tended to have short stroke durations or long end-stop durations, as described above in connection with FIG. 7 and FIG. 9 , respectively. However, after the pump experienced many cycles, the testing data indicated that it tended to leak at the joint area 49 between the manifold seal 47 and the sleeve 24, as shown in FIG. 3B . The reason for the excessive leakage after certain pump cycles was likely a combination of seal wear and tear caused by repetitive pumping motions and high internal pressure caused by blockages. In other words, when the pump 64 was new and the seal 47 was strong enough to tolerate the high pressures caused by blockages, the pump likely exhibited short stroke durations or long end-stop durations (e.g., long limit switch activation durations) during blockages. However, after several pump cycles, the seal may not be strong enough to tolerate the high pressure caused by the occlusion, and the pump 64 may leak through the weakest link in the downstream fluid path, which may be the seal 49 between the manifold 47 and the sleeve 24. Because the fluid in the pump chamber 38 is forced through the leak path by the high internal pressure caused by the occlusion, the pump motor (not shown) is required to provide more energy to push the fluid. As a result, the dispense stroke duration during the occlusion is longer than in normal operation.

[0054] 12A, 12B, 12C, and 12D show several examples from bench occlusion tests of selected types of pumps, such as pump 64, described with reference to FIGS. 1, 2, 3A, 3B, and 3C. FIGS. 12A, 12B, 12C, and 12D illustrate the long dispense durations associated with leakage caused by occlusion. For four drug delivery devices 10, each plot in FIGS. 12A, 12B, 12C, and 12D corresponds to one drug delivery device 10. Each drug delivery device 10 was filled with, for example, 300 U of fluid and delivered with 50 U open, 2 U clamped, and 2 U open. From these plots, it can be seen that when the drug delivery device 10 is occluded, the dispense stroke duration increases, while the aspiration stroke duration remains relatively the same. Therefore, this pump characteristic can be used to detect leakage caused by occlusion.

[0055] In accordance with aspects of the exemplary embodiment of the present invention, the occlusion detection algorithm described above may utilize the pump duration difference between the dispense stroke and the aspirate stroke. For example, with reference to block 108 of FIG. 13, a stroke difference threshold (Th delta ) can be determined as follows:

[0056] Step 1: At the end of loading,

[0057]

number

[0058] Calculate the average duration difference between the aspirate and dispense strokes, defined as:

[0059] where n is the number of strokes used to obtain the average difference. By way of example, n=3 is used for the exemplary embodiment, but it should be understood that this number may vary depending on the specific pump design.

[0060] Step 2: For each pump cycle after loading, collect pump measurement data (e.g., the duration difference between the aspiration stroke and the dispense stroke) for pump 64 (block 109) and compare the duration difference data to pump measurement metrics (block 110), e.g., as follows:

[0061] 1) Calculate the duration difference: Di = Dispense - Aspirate

[0062] 2) Subtract D0 from Di: D'i = Di - D0

[0063] 3) As shown in block 110 of FIG. 13, check whether D'i, D'i-1, and D'i-2 are less than a given threshold (e.g., 0.13 seconds). If yes, normal pump operation can continue per block 112 of FIG. 13. If not, a leak has been detected and the pump may be determined to be experiencing a blockage condition. The counter is set to the threshold Th for normal operation. delta is not met, the counter is incremented (block 111). Referring to block 113, the counter is set to a selected value (e.g., Th for normal operation). delta When the counter reaches a counter value of 8 (corresponding to 8 pump cycles where ≠ 0 is not met), an occlusion is detected, an occlusion indicator can be generated per block 114, and pump operation can be terminated per block 116. If the counter has not yet reached the selected counter value after being incremented per block 111, pump measurement data continues to be collected per block 109. The total number of cycles that the selected number of cycles is reached before an occlusion is indicated can be specified, such as 8 consecutive cycles of 8 cycles, or within a specified number of cycles (e.g., 20 cycles). In the exemplary embodiment, three consecutive dispense strokes are used, although this number may change over time depending on variations in pump duration. Duration Difference D 0,1,…,xare averaged or summarized or categorized and then compared to a threshold or other metric Th between pump measurements for a normally operating pump and a blocked pump. delta The data can be analyzed to determine the extent of the difference (eg, aspiration stroke and dispense stroke duration difference) with respect to the time series.

[0064] The occlusion detection algorithm, according to other exemplary embodiments, may include the leak detection criterion described in conjunction with FIG. 13 in combination with the stroke duration criterion described in conjunction with FIG. 7 and / or the endstop or limit switch actuation duration criterion described in conjunction with FIG. 9. For example, detection using all three of the criteria, or only a single criterion, or a subset of these three criteria, can be performed in parallel or sequentially using occlusion detection software provided to the microcontroller 58 or to a controller of a separate device associated with the drug delivery device 10. Additional exemplary data for the stroke duration criterion is shown in FIG. 10, and additional exemplary data for the switch actuation duration criterion is shown in FIG. 11. Referring to FIG. 14, an exemplary occlusion detection algorithm according to exemplary embodiments uses a combination of the stroke duration criterion described in conjunction with FIG. 7, the endstop or limit switch actuation duration criterion described in conjunction with FIG. 9, and the leak detection criterion described in conjunction with FIG. 13. A counter for a detected occlusion condition is cleared or set to a zero value (block 120). As shown in block 122, pump cycles are detected (i.e., aspiration and dispense strokes are detected, for example, using endstop switch actuation data). Pump measurement data, such as stroke duration, endstop duration, and the average duration difference between aspiration and dispense strokes during loading, as described with reference to FIG. 9, are collected (block 124). The stroke duration difference is determined (i.e., the average duration difference during loading is subtracted from the duration corresponding to the dispense stroke duration being shorter than the aspiration stroke duration (block 126)). The dispense stroke duration reduction (e.g., a 2 second Th per block 128) is calculated. stroke or an end stop switch activation duration extension per block 132 (for example, 1 second Th switch ), or stroke duration difference per block 134 (e.g., Th deltaIf an abnormal pump operating condition, such as a difference greater than 0.01, is detected, the counter is incremented (block 136). When the counter reaches a selected value per block 138 (e.g., a counter value of 8 corresponding to 8 pump cycles where the threshold for normal operation is not met), an occlusion is detected, e.g., per block 114, and an occlusion indicator can be generated and / or pump operation can be terminated. If none of these occlusion conditions are met, the counter remains cleared (e.g., a 0 value) per block 134, the next pump cycle is detected, and associated pump timing or measurement data is collected per block 122.

[0065] For example, the leak detection criteria described above with the occlusion detection algorithm in connection with FIG. 13 were applied in combination with a short stroke duration algorithm (e.g., described above with respect to blocks 80 and 82 of FIG. 7 ) and a long endstop duration algorithm (e.g., described above with respect to blocks 96 and 98 of FIG. 9 ) to bench occlusion data collected from 280 drug delivery devices 10. Table 1 shows a comparison without and with the leak detection algorithm described with respect to blocks 108 and 110 of FIG. 13 . It can be seen that the leak detection algorithm (e.g., blocks 108 and 110 of FIG. 13 ) significantly improved the detection rate of proper occlusions by the occlusion detection algorithm according to an exemplary embodiment of the present invention. However, it slightly increased the false positive rate.

[0066] [Table 1]

[0067] Of the 280 drug delivery devices 10, 120 delivered a 10U bolus before clamping. The manifold seals 49 in these drug delivery devices 10 were minimally used. Table 2 shows a comparison of this group of drug delivery devices 10 without and with a leak detection algorithm. Table 2 shows that when the manifold seals 49 were minimally used, the occlusion detection rate was extremely high at 88%, even without the leak detection algorithm added to the occlusion detection algorithm using stroke duration measurements and / or analysis of long endstop duration pump measurements. These results are consistent with leaks being largely caused by wear and tear on the manifold seals after repetitive pumping motions.

[0068] [Table 2]

[0069] Thus, the leak detection criteria can be implemented within the occlusion detection algorithm. Because the algorithm requires only pump duration information to analyze the leak detection criteria, no hardware modifications are required. An occlusion detection algorithm that uses the leak detection criteria is improved when implemented with the stroke duration criterion and / or the end-stop switch actuation duration criterion to more completely capture all significant pump behavior during occlusion.

[0070] Those skilled in the art will understand that the present disclosure is not limited in its application to the details of construction and arrangement of components set forth in the following description or illustrated in the drawings. The embodiments herein are capable of other embodiments and of being practiced or carried out in various ways. It will also be understood that the phraseology and terminology used herein is for descriptive purposes and should not be regarded as limiting. The use of "including," "comprising," or "having" and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof, as well as additional items. Unless otherwise limited, the terms "connected," "coupled," and "mounted" and variations thereof herein are used broadly and encompass both direct and indirect connections, couplings, and attachments. Furthermore, the terms "connected" and "coupled" and variations thereof are not limited to physical or mechanical connections or couplings. Furthermore, terms such as above, below, bottom, and upper are relative and are used to aid in description and not to be limiting.

[0071] Components of the example devices, systems, and methods used in accordance with the illustrated embodiments of the present invention may be implemented at least partly in digital electronic circuitry, analog electronic circuitry, or in computer hardware, firmware, software, or combinations of them. These components may be implemented as a computer program product, such as a computer program, program code, or computer instructions tangibly embodied in an information carrier or machine-readable storage device for execution by, or to control the operation of, a data processing apparatus, such as a programmable processor, a computer, or multiple computers.

[0072] The computer program can be written in any type of programming language, including compiled or interpreted languages, and can be deployed in any type, including as a stand-alone program or as a module, component, subroutine, or other unit suitable for use in a computing environment. The computer program can be deployed to be executed on one computer, on multiple computers at one site, or distributed across multiple sites and interconnected by a communication network. Functional programs, codes, and code segments for achieving exemplary embodiments of the present invention can also be readily interpreted by programmers skilled in the art to which the present invention pertains as being within the scope of the present invention. Method steps associated with exemplary embodiments of the present invention can be performed by one or more programmable processors that execute computer programs, codes, or instructions to perform functions (e.g., by operating on input data and / or generating output). For example, method steps can also be performed by special purpose logic circuitry, such as an FPGA (field programmable gate array) or an ASIC (application-specific integrated circuit), as may be implemented by apparatus of exemplary embodiments of the present invention.

[0073] The various illustrative logic blocks, modules, and circuits described in connection with the embodiments disclosed herein may be implemented or performed with a general-purpose processor, a digital signal processor (DSP), an ASIC, an FPGA, or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but alternatively, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in association with a DSP core, or any other such configuration.

[0074] Processors suitable for the execution of a computer program include, by way of example, both general-purpose and special-purpose microprocessors, and any one or more processors of any kind of digital computer. Typically, a processor will receive instructions and data from a read-only memory or a random-access memory, or both. The essential elements of a computer are a processor for executing instructions and one or more memory devices for storing instructions and data. Typically, a computer will also include one or more mass storage devices, e.g., magnetic, magneto-optical, or optical disks, for storing data, or be operatively coupled to receive data from or transfer data to them, or both. Suitable information carriers for embodying computer program instructions and data include, by way of example, semiconductor memory devices, e.g., electrically programmable read-only memory or ROM (EPROM), electrically erasable programmable ROM (EEPROM), flash memory devices, and all forms of non-volatile memory, including data storage disks (e.g., magnetic disks, internal hard disks, or removable disks, magneto-optical disks, and CD-ROM and DVD-ROM disks). The processor and memory can be supplemented by, or incorporated in, special-purpose logic circuitry.

[0075] Those skilled in the art will understand that information and signals may be represented using any of a variety of different technologies and techniques. For example, the data, instructions, commands, information, signals, bits, symbols, and chips that may be referred to throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0076] Those skilled in the art will further appreciate that the various illustrative logic blocks, modules, circuits, and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or a combination of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends on the particular application and design constraints imposed on the overall system. Those skilled in the art may implement the described functionality in various ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention. A software module may reside in random access memory (RAM), flash memory, ROM, EPROM, EEPROM, registers, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to a processor such that the processor can read information from and write information to the storage medium. Alternatively, the storage medium may be integral to the processor. In other words, the processor and the storage medium may reside within an integrated circuit or may be implemented as discrete components.

[0077] The non-transitory computer-readable medium includes any type of computer-readable medium, including magnetic storage media, optical storage media, flash media, and solid-state storage media. It should be understood that the software can be installed within and sold along with a central processing unit (CPU) device. Alternatively, the software can be obtained and loaded into the CPU device, including, for example, obtaining the software through a physical medium or a distributed system, including, for example, from a server owned by the software creator or from a server used but not owned by the software creator. The software can be stored on a server for distribution over the Internet, for example.

[0078] The description and illustrations presented above are intended as examples only and are not intended to limit the present invention in any way except as set forth in the following claims. It is particularly noted that those skilled in the art can easily combine various technical aspects of the various elements of the various exemplary embodiments described above in numerous other ways, all of which are considered to be within the scope of the present invention.

Claims

1. a pump comprising: a chamber configured with at least one port for receiving fluid from a reservoir into the chamber and for fluid to exit the chamber; and a pumping mechanism configured to control the aspiration of a predetermined amount of fluid into the chamber during an aspiration stroke and to control the dispensing of a predetermined amount of fluid from the chamber during a dispense stroke; a pump measurement device configured to generate a pump measurement of at least one of each dispense stroke performed by the pump and each aspiration stroke performed by the pump; a processing device configured to analyze pump measurements, including the pump measurements for each of a plurality of the at least one of the aspiration stroke and the dispense stroke, and determine when the pump measurements include a plurality of the pump measurements that satisfy a predetermined metric designated as an indicator of an occlusion; Equipped with the pump measurement corresponds to a duration of at least one of the aspiration stroke and the dispense stroke; the predetermined metric is a selected duration that is greater than an average value of the pump measurements when no blockage occurs in the pump; the pump measurement device is an end-stop switch on the pump configured to be actuated when the pumping mechanism completes the at least one of the aspiration stroke and the dispense stroke, the end-stop switch connected to the processing device for determining a duration of each of the at least one of the aspiration stroke and the dispense stroke; the pump measurements correspond to durations of end-stop switch actuations, and the predetermined metric is a selected duration for end-stop switch actuation that is longer than an average value of the pump measurements when no blockage occurs in the pump; the pump measurements include at least two of the endstop switch actuation duration, the duration of the at least one of the aspiration stroke and the dispense stroke, and the time difference between the aspiration stroke and the dispense stroke, the predefined metric corresponding to a stroke duration being a selected duration that is shorter than an average value of the stroke duration when no blockage occurs in the pump, and the predefined metric corresponding to a dispense stroke duration difference relative to aspiration stroke duration being a selected duration that is greater than an average value of the stroke duration difference when no blockage occurs in the pump, and the processing device is configured to analyze the pump measurements and determine when the pump measurements include a plurality of the pump measurements that satisfy corresponding ones of the predefined metrics. Infusion device with integrated occlusion sensing.

2. 10. The infusion device with integrated occlusion sensing of claim 1, further comprising an indicator, wherein the processing device is configured to operate the indicator as an occlusion alert in response to a determination that a plurality of the pump measurements satisfy the predetermined metric.

3. 2. The infusion device with integrated occlusion sensing of claim 1, wherein the processing device is configured to automatically terminate operation of the pumping mechanism in response to a determination that a plurality of the pump measurements satisfy the predetermined metric.

4. 2. The infusion device with integrated occlusion sensing of claim 1, wherein the pump measurement corresponds to the duration of a dispense stroke in a plurality of the dispense strokes.

5. the pump measurement further corresponds to a duration of the at least one of the aspiration stroke and the dispense stroke; 2. The infusion device with integrated occlusion sensing of claim 1, wherein the predetermined metric further comprises another selected duration that is shorter than the average value of the pump measurements when no occlusion occurs in the pump.

6. 2. The infusion device with integrated occlusion sensing of claim 1, wherein the pump measurement corresponds to the time difference between the aspiration stroke and the dispense stroke, and the predetermined metric corresponding to the dispense stroke duration difference relative to the aspiration stroke duration is a selected duration that is greater than the average value of the stroke duration difference when no occlusion occurs in the pump.

7. 7. The infusion device with integrated occlusion sensing of claim 6, wherein the pump measurements also include the duration of at least one of the aspiration stroke and the dispense stroke, and the predetermined metric corresponding to the stroke duration is a selected duration that is shorter than an average value of the stroke duration when no occlusion occurs in the pump, and the processing device is configured to analyze the pump measurements and determine when the pump measurements include a plurality of the pump measurements that satisfy corresponding ones of the predetermined metrics.

8. operating a pump comprising a chamber configured with at least one port for receiving fluid from a reservoir into the chamber and for fluid to exit the chamber, and a pumping mechanism configured to control the intake of a predetermined amount of fluid into the chamber during an aspiration stroke and to control the dispensing of a predetermined amount of fluid from the chamber during a dispense stroke; operating a pump measurement device to generate a pump measurement of at least one of each aspiration stroke performed by the pump and each dispense stroke performed by the pump; analyzing pump measurements, including the pump measurements for each of a plurality of the at least one of the aspiration stroke and the dispense stroke, to determine when the pump measurements include a plurality of the pump measurements that satisfy a predetermined metric designated as an indicator of an occlusion; operating the pump measurement device to generate a pump measurement corresponding to a duration of at least one of the aspiration stroke and the dispense stroke; using the predetermined metric as a selected duration that is greater than an average value of the pump measurements when no blockages occur in the pump; configuring the pump measurement device as an endstop switch on the pump that is activated when the pumping mechanism completes the at least one of the aspiration stroke and the dispense stroke; connecting the end stop switch to a processing device configured to analyze signals from the end stop switch to determine a duration of each of the at least one of the aspiration stroke and the dispense stroke; Including, the pump measurements correspond to durations of end-stop switch actuations, and the predetermined metric is a selected duration for end-stop switch actuation that is longer than an average value of the pump measurements when no blockage occurs in the pump; the pump measurements include at least two of the endstop switch actuation duration, the duration of the at least one of the aspiration stroke and the dispense stroke, and the time difference between the aspiration stroke and the dispense stroke, the predetermined metric corresponding to stroke duration being a selected duration that is shorter than an average value of the stroke duration when no blockage occurs in the pump, and the predetermined metric corresponding to dispense stroke duration difference relative to aspiration stroke duration being a selected duration that is greater than an average value of the stroke duration difference when no blockage occurs in the pump, and analyzing the pump measurements includes determining when the pump measurements include a plurality of the pump measurements that satisfy corresponding ones of the predetermined metrics. A method for occlusion sensing in an infusion pump.

9. 9. The method of occlusion sensing of claim 8, further comprising activating an indicator occlusion alert in response to determining that a plurality of the pump measurements satisfy the predetermined metric.

10. 9. The method of occlusion sensing of claim 8, further comprising automatically terminating operation of the pumping mechanism in response to determining that a plurality of the pump measurements satisfy the predetermined metric.

11. 9. The method of claim 8, further comprising operating the pump measurement device to generate pump measurements corresponding to the duration of a dispense stroke in a plurality of the dispense strokes.

12. 12. The method of occlusion sensing of claim 11, further comprising using a second said predetermined metric that is a selected duration that is shorter than the average value of said pump measurements when no occlusion occurs in said pump.

13. 9. The method of occlusion sensing of claim 8, wherein the pump measurement corresponds to the time difference between the aspiration stroke and the dispense stroke, and the predetermined metric corresponding to the dispense stroke duration difference relative to the aspiration stroke duration is a selected duration that is greater than the average value of the stroke duration difference when no occlusion occurs in the pump.

14. 14. The method of occlusion sensing of claim 13, wherein the pump measurements also include a duration of at least one of the aspiration stroke and the dispense stroke, the predetermined metric corresponding to the stroke duration being a selected duration that is shorter than an average value of the stroke duration when no occlusion occurs in the pump, and analyzing the pump measurements includes determining when the pump measurements include a plurality of the pump measurements that satisfy a corresponding one of the predetermined metrics.

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