Apparatus and method for normalizing loaded pump motor data to unloaded pump motor data during fluid transfer operations - Patents.com

Abstract

A device and method are provided for improving the accuracy of measured data-based occlusion detection in a fluid delivery device by using deadband normalization of loaded measured data to unloaded measured data. The loaded measured data and unloaded measured data are obtained during the same fluid transfer operation or stroke of the fluid delivery device. The deadband normalization can be performed during an aspirating or dispensing operation. An interface within the fluid delivery device that is proximate to the fluid drive mechanism and capable of at least temporary movement under control but does not move fluid can be used to identify when unloaded measured data should be generated during a fluid transfer operation for deadband normalization of loaded measured data measured during the fluid transfer operation.

Description

[Technical Field]

[0001] The present disclosure and the technical solutions described herein generally relate to performing dead band normalization by normalizing loaded measured data related to fluid movement (e.g., pump motor current measured during a fluid dispensing or aspirating operation when a fluid drive mechanism component is controlled to move fluid) to unloaded measured data obtained when the drive mechanism component is not moving fluid during that dispensing or aspirating operation, and detecting occlusion using dead band normalization. [Background technology]

[0002] 2. Description of Related Art Current detection is a method of detecting occlusions in the fluid pathway of a fluid delivery device, such as an infusion pump, because occlusions cause a decrease in flow, which causes an increase in pressure. The increase in pressure increases the torque demand on the pump motor, and the increased torque demand by the motor draws more current. Other motor parameters besides motor current, such as motor voltage and coded counts, can be used to detect increased pressure.

[0003] However, many other design factors affect the current demand by the motor as well as other motor parameters, including, but not limited to, gearbox efficiency, pump seals and their wear over time, motor efficiency, and motor magnet angle. Additionally, there are environmental factors such as ambient pressure and temperature that can affect motor current demand. These factors can negatively affect the accuracy of detecting blockages using measured pump motor parameters such as motor current.

[0004] overview The above-referenced and other problems are overcome, and further advantages are realized, by the illustrative embodiments.

[0005] According to aspects of an exemplary embodiment, a fluid delivery device is provided, including a pump having a chamber of fluid and a drive mechanism configured to control the movement of a specified volume of fluid relative to the chamber during a fluid movement operation; and a processing device configured to generate measured data during the fluid movement operation, the measured data including unloaded measured data obtained during a portion of the fluid movement operation in which the pump is not moving fluid and loaded measured data obtained while the pump is moving fluid during the fluid movement operation, the measured data being indicative of fluid movement within the pump, and normalizing the loaded measured data to the unloaded measured data.

[0006] According to aspects of the exemplary embodiment, the processing device is further configured to analyze the normalized loaded measured data to determine whether it satisfies a specified metric related to pressure within the infusion device indicative of an occlusion.

[0007] According to aspects of the exemplary embodiment, the processing device is further configured to: generate unloaded measured data during a subsequent fluid transfer operation by the pump during a portion of the subsequent fluid transfer operation in which the pump is not moving fluid; generate loaded measured data while the pump is moving fluid during the subsequent fluid transfer operation, the measured data indicative of fluid movement within the pump; and normalize the loaded measured data to the unloaded measured data.

[0008] According to an aspect of the exemplary embodiment, the fluid transfer operation is an incremental operation between multiple fluid transfer operations for dispensing fluid from or aspirating fluid into the chamber.

[0009] According to aspects of the exemplary embodiment, the processing device is further configured to normalize the loaded measured data to the unloaded measured data for each fluid transfer operation of the fluid delivery device, or for at least a selected subset of the fluid transfer operations of the fluid delivery device.

[0010] According to aspects of the exemplary embodiment, the fluid transfer operation is selected from an aspirating operation for aspirating fluid into the chamber and a dispensing operation for expelling fluid from the chamber.

[0011] According to an aspect of the exemplary embodiment, the measured data is indicative of a fluid characteristic selected from a fluid pressure and a fluid flow rate.

[0012] According to aspects of the exemplary embodiment, the pump is a syringe-type pump having a barrel as a chamber and a plunger, the drive mechanism is operable to selectively drive the plunger to dispense fluid from the barrel, and the processing device is configured to generate unloaded measured data before the measured data indicates that fluid pressure or flow rate has begun to increase from drive of the plunger by the drive mechanism during the fluid transfer operation.

[0013] According to aspects of the exemplary embodiment, the pump is characterized by an interface that includes at least one or more components in the drive mechanism, and the operation generates a portion of the fluid movement operation in which the pump does not move fluid.

[0014] According to aspects of the exemplary embodiment, the pump may be a syringe-type pump having a barrel as a chamber, the interface includes a plunger, the drive mechanism is operable to selectively drive the plunger to dispense fluid from the barrel, and the processing device is configured to generate measured data unloaded during the dispense fluid transfer operation by temporarily retracting the plunger within the barrel by a nominal amount.

[0015] According to aspects of the exemplary embodiment, the pump may be a syringe-type pump having a barrel as a chamber, the interface includes a plunger, the drive mechanism is operable to selectively drive the plunger to dispense fluid from the barrel, and the processing device is configured to generate measured data unloaded during an aspiration fluid transfer operation by manual or externally controlled filling of the barrel via an inlet port to the barrel, and to generate measured data loaded during an aspiration fluid transfer operation by controlling the pump to temporarily retract the plunger into the barrel.

[0016] According to aspects of the exemplary embodiment, the pump may be a syringe-type pump having a barrel as a chamber and a plunger, the interface including a pusher coupled to a drive mechanism, the drive mechanism operable to selectively drive the pusher into contact with the plunger to dispense fluid from the barrel, and the processing device configured to generate unloaded measured data during the dispense fluid transfer operation by temporarily retracting the pusher within the barrel.

[0017] According to aspects of an exemplary embodiment, the pump may be a syringe-type pump having a barrel and a plunger as a chamber, the interface comprising a pusher coupled to a drive mechanism, the drive mechanism operable to selectively drive the pusher into contact with the plunger to dispense fluid from the barrel, and the processing device configured to generate unloaded measured data prior to collecting loaded measured data by incrementing through a known number of dispense cycles in which the pusher has not yet impacted the plunger.

[0018] According to aspects of an exemplary embodiment, the pump may be a rotary metering pump having an inlet port and an outlet port, a drive mechanism connected to the pump motor via a gearbox, a chamber having at least one opening, the drive mechanism operable to selectively drive a piston to dispense or aspirate fluid from the chamber and to control cooperation of the at least one opening with the inlet port during an aspirate fluid transfer operation and with the outlet port during a dispense fluid transfer operation, and an interface including features on the drive mechanism configured to cooperate with the gearbox to enable the drive mechanism not to transfer fluid relative to the chamber during at least a portion of the aspirate fluid transfer operation and the dispense fluid transfer operation.

[0019] According to aspects of an exemplary embodiment, the pump may be a rotary metering pump, wherein the interface includes a pin on the piston that controllably inserts and retracts into the sleeve and a helical groove in the sleeve, wherein the drive mechanism is operable to rotate the sleeve and control the fluid volume in the chamber via the helical groove in the sleeve, and guides the pin to move along the helical groove and guides the retraction and insertion of the piston within the sleeve to control the fluid volume in the chamber, and wherein the pin and / or groove enable the piston to not displace fluid relative to the chamber during at least a portion of a fluid displacing operation.

[0020] According to aspects of the exemplary embodiment, the interface includes a cam coupled to the drive mechanism, and the processing device is configured to generate unloaded measured data during the fluid movement operation when a cam follower connected to an actuator for the drive mechanism traverses at least a portion of a flat portion of the cam to not result in fluid movement during the fluid movement operation.

[0021] According to aspects of an exemplary embodiment, the pump has a reservoir as a chamber, a plunger, and a drive mechanism operable to selectively drive the plunger to dispense fluid from the reservoir, and the processing device is configured with baseline data related to a specified waveform of data measured during a fluid transfer operation, the waveform having a dead portion therein corresponding to when fluid pressure or velocity from driving the plunger by the drive mechanism has not yet begun to increase, and the processing device is configured to analyze the measured data using the baseline data and determine when to generate unloaded measured data during the fluid dispensing operation.

[0022] Additional and / or other aspects and advantages of the exemplary embodiments will be set forth in, will be apparent from, or may be learned by practice of the exemplary embodiments. Exemplary embodiments may include apparatus and methods for operating the same having one or more of the above-described aspects and / or one or more features and combinations thereof. Exemplary embodiments may include one or more features and / or combinations of the above-described aspects, for example, as set forth in the appended claims. [Brief explanation of the drawings]

[0023] The above and / or other aspects and advantages of the exemplary embodiments will be more readily understood from the following detailed description taken in conjunction with the accompanying drawings.

[0024] [Figure 1A] FIG. 1A shows raw and filtered data (e.g., motor current) from an exemplary fluid delivery device during the aspirate and dispense strokes, respectively. [Figure 1B] FIG. 1B shows raw and filtered data (e.g., motor current) from an exemplary fluid delivery device during the aspirate and dispense strokes, respectively. [Figure 1C]FIG. 1C shows filtered measured data (e.g., motor current) and variance at different pressures from an exemplary fluid delivery device during dispensing. [Figure 1D] FIG. 1D shows measured data (e.g., motor current) during operation of an exemplary fluid delivery device, whose drive mechanism components move fluid and do not move fluid, thereby illustrating deadband normalized regions within the data. [Figure 2] FIG. 2 shows measured data (e.g., motor current) from an exemplary fluid delivery device during a dispense operation, and data from regions therein identified for deadband normalization. [Figure 3] FIG. 3 is a flowchart of an example operation of an example fluid delivery device performing a dispense operation with dead-band normalization of measured data according to an example embodiment. [Figure 4] FIG. 4 is a perspective view of an exemplary wearable fluid delivery device employing an occlusion detection algorithm with dead-zone normalization, according to an exemplary embodiment. [Figure 5A] 5A-5C are partial top, perspective, side, and top views, respectively, of the exemplary fluid delivery device of FIG. 1 with the cover removed. [Figure 5B] 5A and 5B are partial top, perspective, side, and top views, respectively, of the exemplary fluid delivery device of FIG. 1 with the cover removed. [Figure 5C] 5A-5C are partial top, perspective, side, and top views, respectively, of the exemplary fluid delivery device of FIG. 1 with the cover removed. [Figure 5D] 5A-5D are partial top, perspective, side, and top views, respectively, of the exemplary fluid delivery device of FIG. 1 with the cover removed. [Figure 6] FIG. 6 is a block diagram of exemplary components of an exemplary fluid delivery device constructed in accordance with an exemplary embodiment. [Figure 7A] 7A-7C are perspective top views of an exemplary fluid delivery device with the cover removed and showing different stages of filling the reservoir. [Figure 7B] 7A and 7B are perspective top views of an exemplary fluid delivery device with the cover removed and showing different stages of filling the reservoir. [Figure 7C] 7A-7C are perspective top views of an exemplary fluid delivery device with the cover removed and showing different stages of filling the reservoir. [Figure 7D] 7A-7D are perspective top views of an exemplary fluid delivery device with the cover removed and showing different stages of filling the reservoir. [Figure 8A] 8A and 8B are front and rear perspective views, respectively, of a plunger driver component constructed in accordance with an exemplary embodiment. [Figure 8B] 8A and 8B are front and rear perspective views, respectively, of a plunger driver component constructed in accordance with an exemplary embodiment. [Figure 9] FIG. 9 is a side view of the plunger driver assembly of the exemplary fluid delivery device of FIGS. 7A-7D shown in the retracted position. [Figure 10A] FIG. 10A is a perspective top view of the exemplary fluid delivery device of FIGS. 7A-7D with the cover removed and showing different stages of expelling fluid from the reservoir via the plunger driver assembly. [Figure 10B] FIG. 10B is a perspective top view of the exemplary fluid delivery device of FIGS. 7A-7D with the cover removed and showing different stages of expelling fluid from the reservoir via the plunger driver assembly. [Figure 10C] FIG. 10C is a perspective top view of the exemplary fluid delivery device of FIGS. 7A-7D with the cover removed and showing different stages of expelling fluid from the reservoir via the plunger driver assembly. [Figure 10D] FIG. 10D is a perspective top view of the exemplary fluid delivery device of FIGS. 7A-7D with the cover removed and showing different stages of expelling fluid from the reservoir via the plunger driver assembly. [Figure 11]FIG. 11 is a perspective view of a center screw having keying features constructed in accordance with an exemplary embodiment for cooperation with the plunger driver component of FIGS. 8A-8B. [Figure 12] FIG. 12 is a partial perspective view of exemplary pump components in an exemplary fluid delivery device operating according to an occlusion detection algorithm using deadband normalization, according to an exemplary embodiment. [Figure 13] FIG. 13 is a partial perspective view of exemplary pump components in an exemplary fluid delivery device operating according to an occlusion detection algorithm using deadband normalization, according to an exemplary embodiment. [Figure 14A] FIG. 14B is a perspective view of the pump components of FIGS. 12 and 13 in an exemplary fluid delivery device arranged according to a ready-to-dispense stage of operation and a ready-to-aspirate stage of operation, respectively. [Figure 14B] FIG. 14A is a perspective view of the pump components of FIGS. 12 and 13 in an exemplary fluid delivery device arranged according to a ready-to-dispense stage of operation and a ready-to-aspirate stage of operation, respectively. [Figure 14C] FIG. 14C is a perspective view of components in an exemplary fluid delivery device including the exemplary pump components of FIGS. 12 and 13 and associated electronic circuitry on a printed circuit board. [Figure 14D] FIG. 14D is a partial perspective view of an exemplary motor and gearbox assembly configured to cooperate with the pump components of FIGS. 12 and 13. [Figure 15A] FIG. 15A is a block diagram of components in an exemplary fluid delivery device. [Figure 15B] FIG. 15B is a schematic diagram of a fluid delivery device pump motor with a current sensor, according to an exemplary embodiment.

[0025] It will be understood that throughout the drawings, like reference numerals refer to like elements, features and structures. DETAILED DESCRIPTION OF THE INVENTION

[0026] DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS As will be appreciated by those skilled in the art, there are numerous ways to implement examples, modifications, and configurations of fluid delivery devices according to the embodiments disclosed herein. Although reference will be made to the exemplary embodiments shown in the drawings and the following description, the embodiments disclosed herein are not meant to be exhaustive of the various alternative designs and embodiments encompassed by the disclosed technical solutions, and those skilled in the art will readily understand that various modifications can be made and various combinations can be made without departing from the scope of the disclosed technical solutions.

[0027] Exemplary embodiments of the present disclosure provide technical solutions to the above-mentioned problems. Due to the aforementioned design and environmental factors that affect the demands on pump motors, it is crucial to adjust or calibrate the pump motor signal used to detect occlusions in fluid delivery devices such as infusion pumps, so that only changes in the motor signal due to changes in pressure are measured and used for occlusion detection, while factors unrelated to pressure, such as changes in the battery, motor, and gearbox over time due to wear, changes in ambient temperature, and differences in pump performance during aspirate versus dispense operations, are not measured. Ideal normalization compensates for everything except pressure, and the exemplary embodiments and technical solutions provided herein have the advantage of being close to ideal normalization.

[0028] The technical solutions and exemplary embodiments provided in the present disclosure employ dead-band normalization. That is, measured data related to a fluid transfer operation controlled by a drive mechanism in a fluid delivery device is adjusted or normalized to data obtained during a dead portion of that operation when the drive mechanism is not moving fluid. The technical solutions and exemplary embodiments provided in the present disclosure advantageously employ dead-band normalization to improve the accuracy of detecting occlusions or other conditions by using normalized measured data. The measured data can be, for example, motor current during a fluid dispensing or aspirating operation. As used herein, "loaded" measured data refers to measured data obtained during a fluid transfer operation when the drive mechanism is moving fluid, and "unloaded" measured data refers to measured data obtained during a dead-band portion of a fluid transfer operation when fluid is not being moved by the drive mechanism. Dead-band normalization is understood to mean that loaded measured data is adjusted or normalized to unloaded measured data during a particular fluid transfer operation in a fluid delivery device. As used herein, "deadband normalization" and "deadband normalization" are advantageous because they remove from measured data undesired signal noise components and / or the effects of undesired deformations associated with the drive mechanism in a fluid delivery device (e.g., a pump motor in a drug infusion device). Removing undesired signal noise or the undesired effects of noise factors (e.g., motor design or environmental factors) from measured data can include, for example, subtracting averaged unloaded measured data from loaded measured data obtained while the pump motor is operating to move fluid. Deadband normalization can also include other mathematical adjustments or calibration operations besides subtraction to normalize measured loaded pump motor data to measured unloaded pump motor data, such as dividing the averaged loaded measured signal by the averaged unloaded measured signal.

[0029] There are different options for normalizing measured data, such as pump motor current in a fluid delivery device. As illustrated by the exemplary embodiment described below, dead-band normalization of measured data to a dead-band region provides significant advantages in terms of the accuracy of detecting a selected delivery device state based on the measured data. For example, one way to normalize pump motor data may be to normalize measured data obtained during a pump's dispense operation to data obtained during a previous aspirate operation, since aspirate operations are not affected by downstream pressure. However, aspirate operations are affected by factors different from dispense operations, such as upstream pressure, reservoir fill volume, and other noise factors that do not affect aspirate and dispense operations equally. For example, normalizing measured pump motor data to the pump's aspirate operation effectively doubles the noise in the measured signal, introducing noise factors not present in dead-band normalization as provided by the technical solution described in this disclosure.

[0030] Various factors affecting motor current include, for example, the resistance of the motor windings, the applied voltage (which varies with, for example, the age of the battery), and the motor speed. Furthermore, the current during a dispensing or aspirating operation can be affected by losses in the gear train, friction losses in the motor, and friction losses in the drive mechanism (e.g., the piston). An advantage of the technical solution described herein is that the desired factor (i.e., the pressure during an aspirating operation PA or a dispensing operation PD) can be obtained by using deadband normalization to remove friction losses and all other constants and factors related to battery replacement, in accordance with the technical solution described herein and its exemplary embodiments.

[0031] See, for example, Figures 1A and 1B, which show raw and filtered pump measurement data (e.g., motor current) from an exemplary fluid delivery device during aspirate and dispense operations, respectively. Figure 1C shows filtered pump measurement data from an exemplary fluid delivery device, showing motor current during dispense and its variance at different pressures. However, all of the illustrated measured current signals share a relatively similar waveform shape, including a first spike 102 corresponding to motor start, a portion 104 of the shape corresponding to piston movement, a portion 106 corresponding to a subsequent valve state change, and an interlock torque spike 108 associated with a rotary metering pump, which is described below in connection with Figures 12-15B.

[0032] Deadband normalization of measured pump motor signals, such as motor current signals during a dispense operation, involves acquiring the current signal when the motor gearbox is rotating but not engaged with the pump. See, for example, FIG. 1D, which shows two superimposed current signal waveforms. One of the waveforms, 112, is acquired during a dispense operation of a rotary metering pump and includes, for example, a motor starting spike 102, a piston movement portion 104, a valve state change 106, and an interlock torque spike 108. The other waveform, 110, is acquired during motor operation without the pump (e.g., the motor is disengaged from the pump drive mechanism). Both of these waveforms have a similar portion 100 corresponding to an identifiable deadband region, and data acquired there during a dispense operation can be used for deadband normalization of measured pump motor data acquired during motor and pump operation to more accurately detect blockage conditions by removing unwanted variability in factors affecting the motor and reducing noise. Deadband normalization to this portion of the signal is advantageous for the following reasons: (1) This portion of the measured pump motor parameter signal is closer in time to the portion of the measurement signal of interest (e.g., measuring current during piston movement to determine pressure changes that may indicate an obstruction), which inherently reduces noise as noise factors change over time, and (2) variations in the battery, motor, and gearbox are deadband-normalized from the analyzed signal since they are essentially the same as the signal from those components alone. Noise factors are understood to mean factors that introduce variability, either internal or external, to a fluid delivery device system, subsystem, or part thereof, such as temperature, humidity, part-to-part variation, part wear, etc.

[0033] It should be understood that the deadband region 100, or the timing during a dispense or aspiration operation for obtaining deadband normalization data, can vary depending on the type of pump and pump drive mechanism. For example, the syringe-style pump described below in connection with Figures 4-11 can be operated to temporarily disengage the pump drive mechanism (e.g., reverse its direction so as not to push the plunger in the syringe-style reservoir to dispense fluid) at any time during a dispense operation to obtain unloaded measured data while no fluid is being moved during the dispense operation. This unloaded measured data is then used to deadband normalize the loaded measured pump motor data obtained during pump engagement that results in the dispensing of fluid. In the case of a manually filled syringe-type pump (e.g., by a supply syringe connected to the inlet port of the pump's syringe-type reservoir), the motor is controlled to perform a controlled aspiration operation, where controlled retraction of the pump piston pulls back the plunger in the syringe-type reservoir to controllably draw more fluid from the supply reservoir into the syringe-type reservoir's fluid chamber, and loaded measured data can be obtained while fluid is being moved. This loaded measured data during controlled aspirant movement can be a dead band normalized to the unloaded measured data obtained during manual filling when the drive mechanism is not being operated to move fluid. Alternatively, in the case of a rotary metering pump described below in connection with FIGS. 12-15B, the dead band region 100 can occur at the beginning of each aspiration stroke and each dispense stroke, as described above in connection with FIGS. 1B, 1D, and 2.

[0034] To optimize the use of deadband normalization in accordance with the technical solutions provided herein, the fluid delivery device has an interface that can move without displacing fluid and that is as close as possible to its fluid drive interface. As described below in connection with FIGS. 7A-7B , in the case of a syringe-type pump, this interface can be a plunger driver component, such as a pusher 216 configured on the end of the drive mechanism, that can abut the reservoir plunger 168 after the reservoir 162 is filled and is controlled to push the plunger 168 toward the distal end of the reservoir to dispense fluid therefrom. For deadband normalization, the pusher 216 can be driven backward, thereby disengaging from the plunger 168. During the dispensing operation, the pusher 216 can be driven forward again to re-engage the plunger 168. By being driven backward, the controller operating according to the deadband normalization algorithm essentially has all of the same effects of a pump motor driving pusher 216 forward (e.g., to dispense), except for forces resulting from friction and pressure on plunger 168. For syringe-style pumps configured without pusher 216 (e.g., its drive mechanism is connected directly to its plunger), the interface can be the plunger being retracted a nominal amount during dispense to obtain unloaded measured data without causing undesired reverse fluid flow. As described below in connection with FIG. 14D, for rotary metering pumps, this interface can be the gap between the gearbox output gear and the piston tab, so that when the gearbox changes direction, there is a period when the piston is not engaged at all (e.g., deadband region 100 of FIG. 2), thus facilitating deadband normalization to function. Therefore, the technical solution described in the present disclosure and its exemplary embodiments advantageously employ loose-fit drivetrain features to obtain and use data unloaded from the dead-band region of fluid movement operations, and thus differs significantly from existing methods of reducing noise and efforts to improve the accuracy of pump motor data readings.

[0035] Operations related to deadband normalization according to exemplary embodiments of the technical solutions described herein are shown in FIG. 3 and can be implemented, for example, as a deadband normalization algorithm executed by a controller (e.g., controller 192 in FIG. 6 or microcontroller 58 in FIG. 15A) or other device processing measured data. According to exemplary embodiments, the controller of the fluid delivery device can be programmed or otherwise configured to take “loaded” measured data when the drive mechanism is operated for fluid movement (e.g., controlled inhalation or aspiration, or controlled output or dispensing) and normalize it with deadband or “unloaded” measured data obtained when the drive mechanism is controlled for a fluid movement operation but is temporarily not moving fluid. According to exemplary embodiments, deadband normalization is performed during an aspiration operation, a dispense operation, or both types of operation. It can be beneficial to do so during filling and delivery (e.g., disengaging and reengaging during any portion of the overall aspiration or dispense stroke depending on the controlled volume intended to be aspirated into or delivered from the fluid chamber). In any event, the deadband normalized data (eg, unloaded measured data) and the loaded measured data are optimally obtained during the same pump aspiration or dispense operation or stroke.

[0036] As shown in block 120 of FIG. 3 , the pump controller can be configured to measure pump motor data associated with a fluid transfer operation (e.g., an aspiration operation or stroke or a dispensing operation or stroke) at the start of the fluid transfer operation (block 122). According to an advantageous aspect of an exemplary embodiment of the technical solution described herein, the controller acquires or generates pump motor data, including unloaded measured data and loaded measured data, during the fluid transfer operation (block 124). The controller performs deadband normalization in accordance with the technical solution described herein by normalizing the loaded measured data to the unloaded measured data corresponding to the fluid transfer operation (block 126). It should be understood that deadband normalization can include, for example, subtracting the unloaded measured data from the measured pump motor data to advantageously determine the fluid pressure or flow rate of the pump during the fluid delivery operation without being affected by signal noise or noise factors (e.g., pump design and environmental factors). The unloaded measured data can be obtained at any point during the fluid transfer operation when the drive mechanism is not moving fluid. The loaded measured data may be obtained at multiple points during a fluid movement operation in which the drive mechanism is involved in moving the fluid. In any event, the loaded and unloaded measured data obtained for that fluid movement operation need not be used for or related to a different fluid movement operation (block 130).

[0037] As previously mentioned, the technical solution described herein successfully compensates for many variations in the pump that are not related to changes in fluid pressure or flow rate or other measured parameters used to detect an occlusion or other condition of the fluid delivery device (e.g., battery, motor, and gearbox design factors, as well as environmental factors such as temperature). Ideal normalization compensates for everything except pressure or flow rate, and this technical solution achieves this essentially ideal normalization through the dead-band normalization shown in accordance with the exemplary embodiments herein. As discussed above with respect to factors affecting motor current, for example, there are many terms and forces that ultimately add to the measured current; the more of these terms or forces that can be normalized, the more accurate occlusion detection using measured parameters can be. Furthermore, dead-band normalization as described herein allows occlusion detection algorithms using dead-band normalization to evaluate individual fluid movement strokes or pump operation without having to look at changes across multiple strokes. Currently, no occlusion detection solutions exist for infusion pumps that involve current sensing or other measured pump motor parameters that utilize the non-driven portion of fluid movement to better assess fluid pressure or flow rate based on current or other measured motor parameters.

[0038]

[0003] Occlusions in fluid delivery devices, such as infusion pumps for medication, can result from restricted flow or pathway narrowing, such as a pinched catheter or tissue blockage, or from an empty medication reservoir. Measuring changes in fluid pressure or flow rate in fluid delivery devices from occlusions or other pump malfunctions is important for early detection to mitigate potential resulting inaccuracies in fluid delivery, such as medication errors. The technical solutions and exemplary embodiments herein achieve more accurate and rapid detection of occlusions, thus resulting in less inaccuracies in fluid delivery.

[0039] The measured data indicates pressure or flow rate and can be any of, but not limited to, motor current, motor voltage, encoder counts, motor drive counts, delivery pulse energy, motor drive time, etc. For example, current sensing is generally considered a reliable method of detecting occlusions in the fluid pathway of fluid delivery because motor current can be indirectly correlated to pressure. As discussed above, occlusions cause a decrease in fluid flow in the fluid delivery device, which causes an increase in pressure. The increase in pressure causes an increase in the torque demand needed by the motor to overcome this pressure. The increase in torque demand corresponds to an increase in the current drawn by the motor, which is one way to detect occlusions such as a blocked catheter, air in the fluid pathway, or a malfunctioning motor.

[0040] 4-11 illustrate an exemplary fluid delivery device having an exemplary interface that facilitates deadband normalization according to an exemplary embodiment. As described below, in a syringe-type fluid delivery mechanism, a drive assembly can selectively engage and disengage the plunger, allowing the pump to be operated without fluid movement to obtain unloaded measured data for deadband normalization according to an exemplary embodiment.

[0041] 12-15B illustrate another example fluid delivery device having a different example interface than Figures 4-11 to facilitate deadband normalization according to an example embodiment. As described below in connection with Figures 12-15B, in a rotary metering fluid delivery mechanism, a gearbox and output gear coupled to a pump drive mechanism allow the pump to be driven without moving fluid to obtain data within the deadband region 100 of an aspirating or dispensing operation to obtain unloaded measured data for deadband normalization according to an example embodiment.

[0042] 4 is a side view of an exemplary wearable fluid delivery device 150 constructed to perform improved occlusion detection in accordance with an exemplary embodiment. The fluid delivery device 150 includes a base plate 152, a cover 154, and an insertion mechanism 156 in an undeployed position.

[0043] 5A, 5B, 5C, and 5D are partial top, perspective, side, and top views, respectively, of the fluid delivery device 150 of FIG. 4 with the cover 154 removed. The base plate 152 supports the insertion mechanism 156, the motor 158, a power source such as a battery 160, a control board 190, and a reservoir 162, or container, for storing fluid to be delivered to a user via an outlet fluid pathway 164 from the reservoir's outlet port to the insertion mechanism 156. The reservoir 162 can also have an inlet port connected to a fill port (e.g., provided in the base plate 12) via an inlet fluid pathway 166. The reservoir 162 includes a plunger 168 having a stopper assembly. A plunger driver assembly 170 is also provided at the proximal end of the reservoir 162. The plunger driver assembly 170 may be telescopic, with the nut 210 rotating via a gear train 172 connected to a counter-rotating sleeve screw 212 and center screw 214, a gear anchor 174, a motor 158, and a gearbox 184. It should be understood that the plunger driver assembly 170 may include other components for pushing and extracting the plunger 168 within the reservoir 162.

[0044] 6 is a block diagram of exemplary components of a fluid delivery device. The cover / housing or housing of device 150 is indicated at 154. Device 150 has a skin retention subsystem 180, such as an adhesive pad, for connecting device 10 to a user's skin. Fluid delivery device 10 further comprises a reservoir 162, an insertion mechanism 156, and a fluid transfer module 182 that may include a motor 158, a motor housing and gearbox 184, a gear train 178, a pump mechanism (e.g., plunger driver assembly 170), and an outlet path 164. The fluid delivery device further comprises electrical components such as a power module (e.g., battery 160), an electrical module 190 comprising a controller 192, a motor driver 194, an optional sensing module 196 for sensing fluid flow conditions (e.g., occlusion), an optional audio driver 198 (e.g., indicating ongoing dosing, low reservoir, occlusion, successful pairing with an external device, or other conditions), and an optional visual driver 200, as well as an optional wireless driver 202 for wireless communication between the fluid delivery device and an optional remote pump control device 203 (e.g., a smartphone or dedicated controller). As described below, the controller 192 can be programmed or otherwise configured to implement the improved occlusion detection of exemplary embodiments of the technical solutions described herein.

[0045] 7A, 7B, 7C, and 7D are perspective top views of the fluid delivery device with the cover removed, showing different stages of filling reservoir 162. Fluid-filled chamber 204 within reservoir 162 is defined by the distal or front side of plunger 168, which is configured to seal fluid from entering the portion of the reservoir defined by the proximal or rear side of the plunger, such that there is no contact with plunger driver assembly 170 or gear anchor 174 as fluid is delivered from the reservoir.

[0046] In FIG. 7A, the reservoir 162 is empty of any fluid and the plunger 168 is in its distal-most position. The plunger driver assembly 170 is shown in a fully retracted position in FIGS. 7A-7D. A user can insert the needle of a filled syringe 176 into a fill port (not shown) in the base plate 152, which has an inlet fluid pathway 166 from the fill port to the reservoir 162, as shown in FIG. 5D. As fluid moves from the syringe 176 to the reservoir 162 via the inlet fluid pathway 166, the volume of the fluid chamber defined in the reservoir 162 by the front face of the plunger 168 increases, as shown in FIGS. 7B, 7C, and 7D, respectively. The plunger 168 has a stopper assembly 169 to prevent leakage of any fluid held within the fluid chamber portion 204 of the reservoir 162. The stopper assembly 169 can comprise, for example, a resilient material similar to that of a syringe stopper.

[0047] As shown in FIGS. 2A-7B , the gear anchor 174 has an opening 222 for receiving the first portion 210 a of the nut 210. The opening 222 has threads 224 configured to cooperate with the external threads 212 a of the sleeve screw 212. The number of threads 224 can be adjusted to balance torque and movement stability. The number of threads 224 can be added without adversely affecting the length (i.e., only minor changes to the geometry of the drive nut are required). The recessed rear surface 226 is configured to rotatably receive the first portion 210 a of the nut 210. The gear anchor 174 has a front surface 228 that can abut the plunger pusher 216 when the plunger driver assembly 170 is fully retracted and the reservoir is filled (e.g., as shown in FIG. 7D ), although this need not be the case depending on the dimensions of the reservoir 162 and the plunger driver assembly 170.

[0048] 8A and 8B are front and rear perspective views, respectively, of plunger pusher 216. Plunger pusher 216 has a detent 230 on its rear surface that receives keying feature 214b on central screw 214. An optional protrusion 232 on the front surface of plunger pusher 216 abuts against the rear surface of plunger 168. Pusher 216 may include features to allow for air venting in addition to, or in place of, a cap on reservoir 22 or plunger driver assembly 170. For example, the air vent feature may be provided along at least a portion of the circumference of pusher 216 and may be in the form of a scalloped edge including notches 216a. If notches 216a are provided on the periphery of pusher 216, these features may be positioned to minimize axial translational friction by biasing the design and tolerances of the peripheral edges of some of these features 216a to be higher than the remaining notch edges so that they initially contact the internal reservoir barrel surface to prevent rotation. Additionally, the pusher 216 may be provided with one or more through holes 216b in the plate-like portion of the pusher for air venting.

[0049] FIG. 9 is a side view of plunger driver assembly 30 in a retracted position relative to gear anchor 34. Referring to FIGS. 9 and 11, plunger driver assembly 170 includes a nut 210 having teeth on a portion thereof that engage gear train 172 and motor 158. A first portion of nut 210a is rotatably received within gear anchor 174. Internal threads within nut 210 engage external threads 212a of sleeve screw 212. Internal threads 212b within a cavity of sleeve screw 212 engage external threads 214a of center screw 214. As described with respect to FIG. 11, the distal end of center screw 214 is provided with keying features 214b that engage detent 230 on plunger pusher 216.

[0050] 10A, 10B, 10C, and 10D are perspective top views of the fluid delivery device with the cover removed, illustrating different stages of expelling fluid from the reservoir via plunger driver assembly 170. In FIG. 10A, plunger driver assembly 170 is in a fully retracted position, maximizing the volume of fluid-filled chamber portion 204 of reservoir 162. In FIGS. 10B, 10C, and 10D, nut 210 is being rotated by motor and gearbox 158 and intermediate power transmission gear train 172 through engagement of its teeth 210b. The inner threads 210b of the nut and the threads 224 of the opening in gear anchor 174 cooperate with the outer threads 212a of sleeve screw 212 to advance sleeve screw 212 through nut 210 and gear anchor 174 and into reservoir 162. At the same time, rotation of sleeve screw 212 causes non-rotational advancement of central screw 214, which is keyed to plunger pusher 216. As a result, plunger 168 advances distally as plunger pusher 216 advances distally to abut plunger 168.

[0051] 8B and 11 , keying features 214b on central screw 214 and corresponding detents 230 on the back surface of plunger pusher 216 provide an anti-rotation mechanism for plunger pusher 216 relative to reservoir 162 when the nut of plunger driver assembly 170 is rotated by motor and gearbox 158 and intermediate power transmission gear train 172. Central screw 214 can be provided with a keying feature for engaging plunger pusher 216. This keying feature can engage with a non-circular plunger pusher shape, whereby rotation is prevented by shape, or can engage with an intermediate structure that acts to prevent rotation within syringe barrel-shaped reservoir 22 during actuation. For example, the distal end of the central screw 214 can be sized and / or shaped to engage with a correspondingly sized and / or shaped detent or indent 230 in the plunger pusher 216, which prevents any limited rotation imparted to the central screw 214 by the other components 210 and 212 from causing rotation of the plunger pusher 216 relative to the inner wall of the reservoir 162.

[0052] As mentioned above, an optional protrusion 232 on the front face of the plunger pusher 216 abuts against the back face of the plunger 168. According to one aspect of the technical solution, the front face of the plunger pusher 216 can controllably engage or abut with the back face of the plunger 168 when the plunger driver assembly 170 is driven by the motor and gearbox 158 to advance toward the distal end of the fluid chamber portion 204 (e.g., to dispense fluid from the chamber), and can be disengaged or spaced apart from the back face of the plunger 168 when the plunger driver assembly 170 is driven by the motor and gearbox 158 to retract toward the gear anchor 174, providing an interface to facilitate deadband normalization (e.g., obtaining unloaded measured data against which loaded measured data can be normalized) according to an exemplary embodiment of the technical solution. For example, the controlled slight retraction of plunger pusher 216 from plunger 168 during a dispense operation allows for deadband normalization determined by controller 192 for comparison and more accurate analysis with measured pump parameters obtained during subsequent dispenses to filter out noise and to more accurately determine pump motor conditions such as catheter occlusion, air in the fluid path, or motor failure, among other fluid delivery device conditions that affect the pressure characteristics of the fluid path. Also, the controller can be configured to generate unloaded measured data before collecting any loaded measured data by incrementing through a known number of dispense cycles in which the pusher has not yet impacted the plunger.

[0053] Exemplary embodiments of the deadband normalization algorithm are also useful with positive displacement pumps. A positive displacement pump is understood to be a type of pump that operates on the principle of filling a chamber (e.g., with liquid drug from a reservoir) in one stage and then emptying the 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 pump or a rotary metering pump can be used. In either case, the piston or plunger is retracted from the chamber to aspirate or draw drug into the chamber, allowing the chamber to fill with a certain 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 certain amount of drug from the chamber (e.g., via an outlet port) into a fluid pathway extending between the pump and the patient's cannula.

[0054] For purposes of illustration, reference is made to the exemplary rotary metering pump described in commonly owned International Publication No. WO 2015 / 157174, the entire contents of which are incorporated herein by reference. The exemplary system diagram of Figure 15A can also show exemplary components in the pumps of Figures 4-11 and other types of pumps.

[0055] 12, 13, 14A, 14B, 14C, 14D, 15A, and 15B, an exemplary rotary metering infusion pump (e.g., a wearable fluid delivery device such as an insulin patch pump) includes a pump assembly 20, which can be connected to a DC motor and gearbox assembly 33 (FIG. 14D), which rotates a sleeve 24 within a pump manifold 22 (FIG. 14D). The sleeve is provided with a helical groove 26. As the sleeve 24 rotates in one direction and then the opposite direction, a coupling pin 28 connected to a piston 30 moves along the helical groove to guide the retraction and insertion of the piston 30 into the sleeve 24, respectively. The sleeve has an end plug 34. Two seals 32, 36 on each end of the piston and end plug within the sleeve 24 define a cavity or chamber 38 when the piston 30 is retracted as shown in FIG. 3A following a suction stroke, thus ready for dispensing. Thus, the volume of chamber 38 varies depending on the degree of retraction of piston 30. The volume of chamber 38 is negligible, or essentially zero, when piston 30 is fully inserted and seals 32, 36 substantially contact one another following the dispense stroke and thus are ready for aspiration, as shown in FIG. 3B. Two ports 44, 46 are provided to pump manifold 22, including an inlet port 44 through which medication can flow from a reservoir 70 (FIG. 4A) for pump 64 (FIG. 4A), and an outlet port 46 through which medication drawn into chamber 38 (e.g., by retraction of piston 30 during the aspiration phase) can be dispensed from chamber 38 into a fluid pathway to, for example, a cannula 72 (FIG. 4A) within the patient, upon reinsertion of piston 30 into chamber 38.

[0056] 12, 13, and 14A-14C, the sleeve 24 can be provided with an opening (not shown) that aligns with either the outlet port 46 or the inlet port 44 (i.e., depending on the degree of rotation of the sleeve 24 and therefore the degree of movement of the piston 30), allowing drug within the chamber 38 to flow through a corresponding one of the ports 44, 46. A pump metering device 78 (FIG. 15A), such as a sleeve rotation limit switch, can be provided, which includes, for example, 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 interlocks 42 can be attached to each end of the manifold 22. When the pump 64 is in the first position, the detents 40 on the end face of the sleeve 24 abut the bumps 48 on the interlock 42, thereby aligning the side hole of the sleeve 24 with the inlet port 44 to receive fluid from the reservoir 70 into the chamber 38. Under certain conditions, such as back pressure, 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 either end of the spiral groove 26. This can result in an incomplete amount of liquid being pumped per 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. 14A. 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. 15A) increases the torque on the sleeve 24 beyond the threshold, bending the interlock 42 and allowing the detent 40 to pass over the bump 48. Once sleeve 24 has been rotated to its full extent so that its side holes face towards cannula 72 or exit port 46, detent 40 passes over bump 48 in interlock 42, as shown in Figure 14B.Another sleeve mechanism 41 may be provided to engage an electrical switch (e.g., an end stop switch 90 provided on a printed circuit board 92 and positioned relative to the sleeve and / or end plug 34 to cooperate with a pump metering device 78 as shown in FIG. 14C).

[0057] The gap between piston 30 and gearbox output gear 39 (e.g., between tab 31 on the end of the piston and sl5t 35 on output gear 39) provides a useful interface for deadband normalization because it is close to a fluid drive interface that can move, at least temporarily, without moving fluid during a fluid-moving operation. For example, as shown in FIG. 1D, even when the drive mechanism manipulates pump piston 30 in a pump aspirate or dispense operation to move fluid, the initial point 100 of the new direction after motor start is similar to the unloaded measured data, and the loaded measured data can be normalized to this unloaded measured data.

[0058] FIG. 14D shows a portion of the manifold 22 having the motor and gearbox 33 cooperating with the pump assembly 20. The motor and gearbox 33 includes an opening 43 capable of receiving a rotation limit switch. In this manner, the output gear 39, which is internal to the gearbox housing, can access and engage the flexures of the limit switch. The motor and gearbox 33 also includes an axial retention snap 37 so that the pump assembly 20 can snap fit onto the motor and gearbox 33. The motor and gearbox 33 includes a rotation key 41 within the pump receiving socket 43 to receive the pump assembly 20 and prevent rotation of the pump assembly 20 relative to the motor and gearbox 33. The output gear 39 includes a slot 35 adapted to receive a tab 31 on the piston 30. When assembled, the tab 31 is received within the slot 35, allowing the output gear 39 to transfer torque to the piston 30. As the output gear 39 rotates, the pump piston tab 31 rotates and slides axially within the slot 35, providing a useful interface for obtaining unloaded measured data for deadband normalization with the corresponding loaded measured data when the piston is displacing fluid into or out of the chamber 38. The bent portions of the metal springs on the motor connections and limit switches are used to make electrical contact with pads on the circuit board 92 during final assembly.

[0059] Alternatively, an interface that can facilitate deadband normalization in an exemplary rotary metering infusion pump can be designed with the helical groove 26 and coupling pin 28. During the exhaust stroke, the piston 30 is rotated in a first rotational direction and driven along the helical path of the helical groove 26 in the sleeve 24 via the coupling pin 28. As the pump piston 30 rotates, it moves away from the gearbox, expelling fluid from the pump chamber 38 and from the cannula port 1356. During the exhaust stroke, friction between the port seal and the outer diameter of the sleeve 24 is sufficient to ensure that the sleeve does not rotate during this portion of the pump cycle. During the valve state change after the exhaust stroke, the coupling pin 28 reaches the distal end of the helical groove 26, and torque continues to be transmitted from the output gear to the pump piston 30 and then through the coupling pin 28 to the sleeve 24. The sleeve 24 and pump piston 30 rotate as a unit without relative axial motion. The side hole of the sleeve 24 moves from the outlet port 46 to the inlet port 44. During the intake stroke, the output gear rotates the pump piston 30, which moves axially relative to the sleeve 24 due to the interaction of the coupling pin 28 in the helical groove 26. The pump piston 30 moves toward the gearbox, drawing fluid from the reservoir into the pump chamber through the inlet port 44. During the valve state change after the intake stroke, the coupling pin 28 reaches the top of the helical groove 26, and the pump motor continues to supply torque, rotating the sleeve 24 and piston 30 together as a unit with no relative axial motion, moving the side hole in the sleeve 24 from alignment with the inlet port 44 to alignment with the outlet port 46. The helical groove 26 and coupling pin 28 can be configured by extending or otherwise modifying the dimensions or slope of the groove to provide a dead zone (e.g., 100 in FIG. 2 ) in the fluid-moving operation, where the drive mechanism component acts to provide an interface for dead-zone normalization but does not move fluid.

[0060] According to another exemplary embodiment, a fluid delivery device can have a drive mechanism that uses one or more cams, which can provide a useful interface for dead-zone normalization according to the technical solution of the present invention. Unloaded measured data for dead-zone normalization can be obtained, for example, using the dead zone provided by the cam and cam follower. At a point during a fluid movement operation in which an actuator with a cam follower is controlled to rotate relative to the cam, the cam follower advances along the flat surface of the cam, preventing associated gears or other components connected to the cam from operating and moving fluid during the fluid movement operation.

[0061] Regardless of the type of actuator and drive mechanism used in a fluid delivery device, such as a wearable infusion pump, deadband normalization advantageously uses an unloaded region or portion of a positive displacement pump fluid movement operation to obtain unloaded measured data related to fluid movement (e.g., pressure, flow rate, etc.) and use it to normalize loaded measured data related to that fluid movement operation. The resulting normalized measured data is advantageous because it removes the effects of actuator-related signal noise and external noise factors (e.g., environmental factors and part-to-part variations), allowing for more accurate occlusion detection using the normalized measured data. Another advantage of deadband normalization according to the technical solutions and exemplary embodiments described herein is that the unloaded and loaded measured data signals used for deadband normalization are processed very locally, i.e., near a particular fluid movement event (e.g., a particular aspiration or dispense stroke). It should be understood that this local or proximal operation is not limited by the particular timing or order of operations for obtaining loaded and unloaded measured data during any particular fluid movement event or operation.

[0062] It will be understood by those skilled in the art that the present disclosure is not limited in its application to the details of the configuration and arrangement of components illustrated in the foregoing description or in the drawings. The embodiments herein are capable of other embodiments and of being practiced or carried out in various ways. It is also understood that the phraseology and terminology used herein are for the purpose of description and are not to 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 up, down, bottom, and top are relative and are used to aid in description, but are not limiting.

[0063] Components of the example devices, systems, and methods used in accordance with the illustrated embodiments can be implemented at least partially in digital electronic circuitry, analog electronic circuitry, or computer hardware, firmware, software, or combinations thereof. The components can also 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.

[0064] The computer program can be written in any form of programming language, including compiled or interpreted languages, and can be deployed in any form, such 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 run on one computer or multiple computers at one site, or distributed across multiple sites and interconnected by a communication network. Furthermore, functional programs, codes, and code segments for achieving the exemplary embodiments can be readily interpreted by a programmer skilled in the art to which the exemplary embodiments pertain, as being within the scope of the claims illustrated by the exemplary embodiments. Method steps associated with the exemplary embodiments 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). Method steps can also be performed by, and apparatus of the exemplary embodiments can be implemented as, special purpose logic circuitry, such as, for example, a field programmable gate array (FPGA) or an application-specific integrated circuit (ASIC).

[0065] The various illustrative logic blocks, modules, and circuits described in connection with the embodiments disclosed herein may be implemented or performed by a general-purpose processor, a digital signal processor, 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 in the alternative, 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.

[0066] Processors suitable for executing 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 receives 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 also includes one or more mass storage devices, such as magnetic, magneto-optical, or optical disks, for storing data, or is operatively coupled to receive and / or transfer data. Information carriers suitable 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 may be supplemented by, or incorporated in, special-purpose logic circuitry.

[0067] Those skilled in the art will appreciate 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 referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0068] 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 can 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 claims as exemplified by the exemplary embodiments. 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 the 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.

[0069] Computer-readable non-transitory media include all types of computer-readable media, including magnetic storage media, optical storage media, flash media, and solid-state storage media. It should be understood that the software can be installed on a central processing unit (CPU) and sold therewith. Alternatively, the software can be obtained and loaded onto the central processing unit, including, for example, obtaining the software via a physical medium or distribution system, including, for example, a server owned by the software creator or a server used by but not owned by the software creator. The software can be stored on a server for distribution, for example, via the Internet.

[0070] The above description and figures are intended to be illustrative only and are not intended to limit the exemplary embodiments in any way except as set forth in the claims. It is particularly noted that those skilled in the art can readily 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 claims.

Claims

1. a pump comprising a chamber of fluid and a drive mechanism configured to control the movement of a specified volume of fluid to the chamber during a fluid movement operation; a processing device configured to generate, during a fluid transfer operation, measured data including unloaded measured data obtained during a portion of the fluid transfer operation in which the pump is not moving fluid and loaded measured data obtained while the pump is moving fluid during the fluid transfer operation, the measured data being indicative of fluid movement within the pump, and to adjust the loaded measured data with the unloaded measured data to remove noise factors; Equipped with the fluid transfer operation is selected from an aspirating operation for aspirating fluid into the chamber and a dispensing operation for discharging fluid from the chamber. Fluid delivery devices.

2. 10. The fluid delivery device of claim 1, wherein the processing device is further configured to analyze the adjusted loaded measured data to determine whether a specified indicator related to pressure within the infusion device indicative of an occlusion is met.

3. The fluid transfer operation is an incremental operation between multiple fluid transfer operations for dispensing fluid from or aspirating fluid into the chamber; The processing device, during each fluid movement operation by the pump, generating unloaded measured data during a portion of the fluid moving operation in which the pump is not moving fluid; generating loaded measured data while the pump is moving fluid during the fluid moving operation, the measured data indicative of fluid movement within the pump; adjusting the loaded measured data with the unloaded measured data; further configured as follows: The fluid delivery device of claim 1 .

4. The fluid delivery device of claim 1 , wherein the fluid transfer operation is an incremental operation between multiple fluid transfer operations for dispensing fluid from or aspirating fluid into the chamber.

5. The fluid transfer operation is an incremental operation between multiple fluid transfer operations for dispensing fluid from or aspirating fluid into the chamber; 10. The fluid delivery device of claim 1, wherein the processing device is further configured to adjust the loaded measured data with the unloaded measured data for each fluid transfer operation of the fluid delivery device, or at least for a selected one or more of the plurality of fluid transfer operations of the fluid delivery device.

6. The fluid delivery device of claim 1 , wherein the measured data is indicative of a fluid characteristic selected from fluid pressure and fluid flow rate.

7. 2. The fluid delivery device of claim 1, wherein the pump is a syringe-type pump having a barrel and a plunger as the chamber, the drive mechanism is operable to selectively drive the plunger to dispense fluid from the barrel, and the processing device is configured to generate the unloaded measured data before the measured data indicates that fluid pressure or flow rate has begun to increase from drive of the plunger by the drive mechanism during the fluid transfer operation.

8. A pump comprising: a fluid chamber; and a drive mechanism configured to control the movement of a specified volume of fluid to said chamber during a fluid movement operation; a processing device configured to generate, during a fluid transfer operation, measured data including unloaded measured data obtained during a portion of the fluid transfer operation in which the pump is not moving fluid and loaded measured data obtained while the pump is moving fluid during the fluid transfer operation, the measured data being indicative of fluid movement within the pump, and to adjust the loaded measured data with the unloaded measured data to remove noise factors; Equipped with the fluid transfer operation is selected from an aspirating operation for aspirating fluid into the chamber and a dispensing operation for discharging fluid from the chamber; the pump is a syringe-type pump having a barrel as the chamber and characterized by an interface including at least one or more components within the drive mechanism, and operation generates the portion of the fluid movement operation in which the pump does not move fluid; the interface includes a plunger; the drive mechanism is operable to selectively drive the plunger to dispense fluid from the barrel; the processing device is configured to generate the unloaded measured data during a dispense fluid transfer operation by temporarily retracting the plunger within the barrel a nominal amount. Fluid delivery devices.

9. A pump comprising: a fluid chamber; and a drive mechanism configured to control the movement of a specified volume of fluid to said chamber during a fluid movement operation; a processing device configured to generate, during a fluid transfer operation, measured data including unloaded measured data obtained during a portion of the fluid transfer operation in which the pump is not moving fluid and loaded measured data obtained while the pump is moving fluid during the fluid transfer operation, the measured data being indicative of fluid movement within the pump, and to adjust the loaded measured data with the unloaded measured data to remove noise factors; Equipped with the fluid transfer operation is selected from an aspirating operation for aspirating fluid into the chamber and a dispensing operation for discharging fluid from the chamber; the pump is a syringe-type pump having a barrel as the chamber and characterized by an interface including at least one or more components within the drive mechanism, and operation generates the portion of the fluid movement operation in which the pump does not move fluid; the interface includes a plunger; the drive mechanism is operable to selectively drive the plunger to dispense fluid from the barrel; the processing device is configured to generate the unloaded measured data before collecting the loaded measured data by incrementing through a known number of dispense cycles in which a pusher has not yet struck the plunger. Fluid delivery devices.

10. A pump comprising: a fluid chamber; and a drive mechanism configured to control the movement of a specified volume of fluid to said chamber during a fluid movement operation; a processing device configured to generate, during a fluid transfer operation, measured data including unloaded measured data obtained during a portion of the fluid transfer operation in which the pump is not moving fluid and loaded measured data obtained while the pump is moving fluid during the fluid transfer operation, the measured data being indicative of fluid movement within the pump, and to adjust the loaded measured data with the unloaded measured data to remove noise factors; Equipped with the fluid transfer operation is selected from an aspirating operation for aspirating fluid into the chamber and a dispensing operation for discharging fluid from the chamber; the pump is a syringe-type pump having a barrel as the chamber and characterized by an interface including at least one or more components within the drive mechanism, and operation generates the portion of the fluid movement operation in which the pump does not move fluid; the interface includes a plunger; the drive mechanism is operable to selectively drive the plunger to dispense fluid from the barrel; the processing device is configured to generate the unloaded measured data during an aspiration fluid transfer operation by manual or externally controlled filling of the barrel through an inlet port to the barrel, and to generate the loaded measured data during an aspiration fluid transfer operation by controlling the pump to temporarily retract the plunger within the barrel. Fluid delivery devices.

11. A pump comprising: a fluid chamber; and a drive mechanism configured to control the movement of a specified volume of fluid to said chamber during a fluid movement operation; a processing device configured to generate, during a fluid transfer operation, measured data including unloaded measured data obtained during a portion of the fluid transfer operation in which the pump is not moving fluid and loaded measured data obtained while the pump is moving fluid during the fluid transfer operation, the measured data being indicative of fluid movement within the pump, and to adjust the loaded measured data with the unloaded measured data to remove noise factors; Equipped with the fluid transfer operation is selected from an aspirating operation for aspirating fluid into the chamber and a dispensing operation for discharging fluid from the chamber; the pump is a syringe-type pump having a barrel and a plunger as the chamber, characterized by an interface including at least one or more components in the drive mechanism, and operation generates the portion of the fluid movement operation in which the pump does not move fluid; the interface comprises a pusher coupled to the drive mechanism; the drive mechanism is operable to selectively drive the pusher into contact with the plunger to dispense fluid from the barrel; the processing device is configured to generate the unloaded measured data during a dispense fluid transfer operation by temporarily retracting the pusher within the barrel. Fluid delivery devices.

12. A pump comprising: a fluid chamber; and a drive mechanism configured to control the movement of a specified volume of fluid to said chamber during a fluid movement operation; a processing device configured to generate, during a fluid transfer operation, measured data including unloaded measured data obtained during a portion of the fluid transfer operation in which the pump is not moving fluid and loaded measured data obtained while the pump is moving fluid during the fluid transfer operation, the measured data being indicative of fluid movement within the pump, and to adjust the loaded measured data with the unloaded measured data to remove noise factors; Equipped with the pump is a rotary metering pump having an inlet port and an outlet port, characterized by an interface including at least one or more components within the drive mechanism, and wherein operation generates the portion of fluid movement in which the pump does not move fluid; the drive mechanism is connected to a pump motor via a gearbox; the chamber has at least one opening; the drive mechanism is operable to selectively drive a piston to dispense or aspirate fluid from the chamber and to control cooperation of the at least one opening with the inlet port during an aspirate fluid transfer operation and with the outlet port during a dispense fluid transfer operation; the interface includes a feature on the drive mechanism configured to cooperate with the gearbox to allow the drive mechanism to not move fluid relative to the chamber during at least a portion of the aspirate fluid transfer operation and the dispense fluid transfer operation; Fluid delivery devices.

13. A pump comprising: a fluid chamber; and a drive mechanism configured to control the movement of a specified volume of fluid to said chamber during a fluid movement operation; a processing device configured to generate, during a fluid transfer operation, measured data including unloaded measured data obtained during a portion of the fluid transfer operation in which the pump is not moving fluid and loaded measured data obtained while the pump is moving fluid during the fluid transfer operation, the measured data being indicative of fluid movement within the pump, and to adjust the loaded measured data with the unloaded measured data to remove noise factors; Equipped with the pump is a rotary metering pump and is characterized by an interface including at least one or more components within the drive mechanism, the operation causing the portion of the fluid movement operation in which the pump does not move fluid; the interface includes a pin on the piston that controllably inserts and retracts into a sleeve and a spiral groove in the sleeve; the drive mechanism is operable to rotate the sleeve to control a fluid volume in the chamber via a spiral groove in the sleeve, and to guide the pin to move along the spiral groove to guide the retraction and insertion of the piston within the sleeve to control a fluid volume in the chamber, the pin and / or groove enabling the piston to not move fluid relative to the chamber during at least a portion of a fluid moving operation; Fluid delivery devices.

14. A pump comprising: a fluid chamber; and a drive mechanism configured to control the movement of a specified volume of fluid to said chamber during a fluid movement operation; a processing device configured to generate, during a fluid transfer operation, measured data including unloaded measured data obtained during a portion of the fluid transfer operation in which the pump is not moving fluid and loaded measured data obtained while the pump is moving fluid during the fluid transfer operation, the measured data being indicative of fluid movement within the pump, and to adjust the loaded measured data with the unloaded measured data to remove noise factors; Equipped with the pump is characterized by an interface that includes at least one or more components within the drive mechanism, and the operation generates the portion of the fluid movement operation in which the pump does not move fluid; the interface includes a cam coupled to the drive mechanism; the processing device is configured to generate the unloaded measured data during a fluid movement operation when a cam follower connected to an actuator for the drive mechanism traverses at least a portion of a flat portion of the cam to not result in fluid movement during the fluid movement operation. Fluid delivery devices.

15. A pump comprising: a fluid chamber; and a drive mechanism configured to control the movement of a specified volume of fluid to said chamber during a fluid movement operation; a processing device configured to generate, during a fluid transfer operation, measured data including unloaded measured data obtained during a portion of the fluid transfer operation in which the pump is not moving fluid and loaded measured data obtained while the pump is moving fluid during the fluid transfer operation, the measured data being indicative of fluid movement within the pump, and to adjust the loaded measured data with the unloaded measured data to remove noise factors; Equipped with the pump having a reservoir as the chamber, a plunger, and a drive mechanism operable to selectively drive the plunger to dispense fluid from the reservoir; the processing device is configured with baseline data related to a designated waveform of the measured data during a fluid movement operation, the waveform having a dead portion therein corresponding to a time when fluid pressure or velocity from actuation of the plunger by the actuation mechanism has not yet begun to increase; the processing device is configured to analyze the measured data using the baseline data to determine when to generate the unloaded measured data during a fluid dispensing operation. Fluid delivery devices.

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