Capacitive sensing for detecting the position of components

Abstract

In this application, drug delivery devices and methods for positioning pump components, such as linear shuttle pumps, are disclosed. In some approaches, a system includes a first terminal and a second terminal movable relative to one another, and a sensor device operable to detect a change in capacitance between the first terminal and the second terminal as the first terminal and the second terminal move relative to one another. The sensor device includes a two-stage charging device connected to a controller and a voltage source, the two-stage charging device having a first capacitor connected to a first switch and a second capacitor connected to a second switch, the controller operable to close the first switch to connect the first capacitor to the voltage source and charge the first capacitor, and to open the first switch and close the second switch to connect the second capacitor to the voltage source and charge the second capacitor.

Description

Technical Field

[0001] (Related Application) This application claims the benefit of U.S. Provisional Patent Application No. 63 / 284,150, filed Nov. 30, 2021. The entire contents of that application are incorporated herein by reference.

[0002] Embodiments described herein generally relate to drug delivery. More specifically, embodiments described herein relate to wearable drug delivery devices and methods that use capacitance sensing to detect the position of pump device elements.

Background Art

[0003] Many wearable drug delivery devices include a reservoir for storing a liquid drug, and a drive mechanism, such as a pump having a pump chamber and a piston, that discharges the stored liquid drug from the reservoir for delivery to a user. A drawback of known devices is that the accuracy of the delivery amount decreases when the volume of the liquid is small. Such inaccuracies have manifested in many cases where drive mechanisms that introduce variability in the delivery amount are employed. Accordingly, there is a need to provide a wearable drug delivery device that can adjust the dosage of drug delivery while simultaneously ascertaining the position and sequencing of the drive mechanism.

Summary of the Invention

[0004] In some embodiments of the present disclosure, the system may include a first terminal and a second terminal that are movable relative to each other, and a sensor device that is operable to detect changes in capacitance between the first terminal and the second terminal as the first terminal and the second terminal move relative to each other. The sensor device may include a two-stage charging device connected to a controller and a voltage source, the two-stage charging device comprising a first capacitor connected to a first switch and a second capacitor connected to a second switch, the controller operable to close the first switch to connect the first capacitor to the voltage source and charge the first capacitor, and to open the first switch and close the second switch to connect the second capacitor to the voltage source and charge the second capacitor.

[0005] In some embodiments of the present disclosure, a wearable drug delivery device may comprise a first terminal and a second terminal movable relative to each other, wherein the first terminal is part of a pump mechanism, and the linear shuttle pump may further comprise a sensor device operable to detect changes in capacitance between the first terminal and the second terminal as the first and second terminals move relative to each other. The sensor device may comprise a two-stage charging device connected to a controller and a voltage source, wherein the two-stage charging device comprises a first capacitor connected to a first switch and a second capacitor connected to a second switch, and the controller is operable to close the first switch to connect the first capacitor to the voltage source and charge the first capacitor, and to open the first switch and close the second switch to connect the second capacitor to the voltage source and charge the second capacitor.

[0006] In some embodiments of the present disclosure, a linear shuttle pump may include a first terminal and a second terminal that are movable relative to each other, wherein the first terminal is part of the pump mechanism, and the linear shuttle pump may further include a sensor device that is operable to detect a change in capacitance between the first terminal and the second terminal as the first terminal and the second terminal move relative to each other. The sensor device may include a two-stage charging device connected to a controller and a voltage source, the two-stage charging device comprising a first capacitor connected to a first switch and a second capacitor connected to a second switch, the controller operable to close the first switch to connect the first capacitor to the voltage source and charge the first capacitor, and to open the first switch and close the second switch to connect the second capacitor to the voltage source and charge the second capacitor.

[0007] In some embodiments of the present disclosure, the method may include positioning a first terminal adjacent to a second terminal, wherein the first and second terminals are movable relative to each other; and detecting a change in capacitance between the first and second terminals using a sensor device, wherein the sensor device comprises a two-stage charging device connected to a controller and a voltage source. The method may further include charging the first capacitor by the controller by closing a first switch and connecting the first capacitor to the voltage source; and charging the second capacitor by the controller by opening the first switch and closing a second switch and connecting the second capacitor to the voltage source.

[0008] The accompanying drawings illustrate exemplary approaches of this disclosure, including practical applications of the principles of the present invention. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 shows a perspective view of an exemplary linear shuttle type fluid pump according to an embodiment of the present disclosure. [Figure 2] Figure 2 shows an end view of the linear shuttle type fluid pump depicted in Figure 1, according to an embodiment of the present disclosure. [Figure 3A] Figure 3A is a simplified diagram of the first and second terminals in use according to an embodiment of the present disclosure. [Figure 3B] Figure 3B is a simplified diagram of the first and second terminals in use according to an embodiment of the present disclosure. [Figure 4] Figure 4 is a schematic diagram of a sensor device according to an embodiment of the present disclosure. [Figure 5A] Figure 5A is a graph showing a continuous voltage charging curve according to an embodiment of the present disclosure. [Figure 5B] Figure 5B is a graph showing a continuous voltage charging curve according to an embodiment of the present disclosure. [Figure 6] Figure 6 is a schematic diagram of a sensor device according to an embodiment of the present disclosure. [Figure 7A] Figure 7A is a graph showing a continuous voltage charging curve according to an embodiment of the present disclosure. [Figure 7B] Figure 7B is a graph showing a continuous voltage charging curve according to an embodiment of the present disclosure. [Figure 8] Figure 8 shows a process according to an embodiment of the present disclosure. [Figure 9] Figure 9 shows a process according to an embodiment of the present disclosure. [Figure 10] Figure 10 shows a schematic diagram of a drug delivery system according to an embodiment of the present disclosure.

[0010] The drawings are not necessarily to scale. The drawings are for illustrative purposes only and are not intended to depict specific parameters of the disclosure. The drawings are intended to depict exemplary embodiments of the disclosure and are therefore not intended to limit the scope. In the drawings, similar reference numerals indicate similar elements.

[0011] Furthermore, for the sake of clarity, certain elements in the drawings may be omitted or drawn not to scale. Cross-sectional views may be in the form of "slices" or "near-sighted" cross-sections, omitting certain background lines that would be visible in a "true" cross-section. Additionally, some reference numerals may be omitted in certain drawings. [Modes for carrying out the invention]

[0012] Various approaches relating to this disclosure are described more fully below with reference to the accompanying drawings, and embodiments of the methods are also shown. The approaches can be embodied in many different forms and should not be construed as being limited only to the embodiments described herein. Rather, these embodiments are provided so that this disclosure is more thorough and complete, and so as to convey more fully to those skilled in the art the scope of the approaches.

[0013] The various examples disclosed herein provide drive mechanisms and / or pump systems with the ability to control and more accurately verify the position and sequencing of the pump. As a result, drug delivery devices, including reservoirs and pumps, can become more reliable and therefore safer for the user.

[0014] The various examples described herein enable a pump, such as a linear volume shuttle pump (LVSP), to execute a pumping cycle in an appropriate sequence. Knowing the positions of different pump elements, namely the pump chamber and the piston, at any given time during pump operation is beneficial because the pump chamber and the piston are responsible for fluid intake and discharge. Knowing the positions of both the pump chamber and the piston can also suggest whether the pump is operating in the designed sequence. In some examples of the present disclosure, the first terminal or contact is coupled to the piston and disposed on the piston grip, and the second terminal or contact may be disposed under the piston grip. In some examples, the second terminal can be a conductive element or conductive plate (e.g., made of copper) that is coupled to or embedded within or on top of a printed circuit board (PCB). As described in more detail herein, the capacitance formed between the two terminals can be used to detect the position of the moving mechanical part of the pump, which can in turn be used to track the positions of the chamber and the piston. The position information about the pump chamber obtained by the system can be used, for example, to ensure that the pump properly intakes or discharges fluid and ultimately to ensure the volume of fluid that is intaken or discharged.

[0015] Although this specification is described in the context of an LVSP, other types of pump mechanisms for wearable drug delivery devices are also possible within the scope of the present disclosure. Further, the wearable drug delivery device described herein may include an analyte sensor such as a blood glucose sensor, and the cannula or microneedle array of the sensor may be operable to enable the device to measure the analyte level of the user of the device.

[0016] Figures 1-2 show an LVSP 100 (hereinafter, the "pump") according to an embodiment of the present disclosure. As shown, the pump 100 may comprise a pump housing 102, which is coupled and integrated with a fluid reservoir 104, a pump chamber 106, and a piston 108. In the shown position, the piston 108 can be fully inserted into the pump chamber 106 at the end of its stroke. In some embodiments, the fluid reservoir 104 may contain a fluid or liquid agent. The pump housing 102 may comprise a base 110, a chassis 111 extending from the base 110 for holding the pump chamber 106, and a reservoir wall 112 operable to interface with the pump chamber 106. The pump housing 102 may be formed from injection-molded plastic or other similar material.

[0017] Although not shown, the pump chamber 106 may include an inlet passage or inlet element and an outlet passage or outlet element. Liquid or fluid can enter the pump chamber 106 through the inlet passage and exit the pump chamber 106 through the outlet passage. One or more plunger elements can work together with the inlet and outlet passages to draw fluid into the pump chamber 106 and discharge the fluid from the pump chamber 106. In various examples, the pump chamber 106 may be coupled to a fluid reservoir 104 that stores a fluid or liquid drug. For example, the inlet may be coupled to the fluid reservoir 104, and the outlet passage may be coupled to a fluid pathway element (not shown) that is coupled to a patient or user to receive the fluid drug stored in the fluid reservoir 104.

[0018] As further illustrated, pump 100 may include a detent device 115 coupled to pump chamber 106. In some embodiments, this detent device 115 may include a detent cap or body 116, one or more detent arms 117 extending from the detent body 116, and one or more detent engagement members 118. As shown, the detent engagement member 118 may extend from the base 110. The detent body 116 may extend over and / or abut one end of the pump chamber 106. In some embodiments, the detent body 116 may further abut the piston 108, where an opening (not shown) in the detent body 116 may be sized such that the rod 132 (FIG. 2) of the piston 108 can pass therethrough. It should be understood that the detent device 115 described above is non-limiting and that other pump configurations are possible within the scope of the present disclosure.

[0019] The detent arm 117 may include one or more capture positions that may be recesses or valleys disposed between one or more peaks. The capture positions may be curved to generally conform to the dimensions of the detent engagement member 118 and may, in this example, include rounded protrusions 122. The capture positions may enable discrete positioning of the pump chamber 106 and / or the piston 108 by applying additional frictional forces that limit movement of the detent body 116 prior to a desired time.

[0020] As further illustrated, the pump 100 may include a piston grip 125 coupled to a piston 108. The piston grip 125 may include one or more grip elements (not shown) that engage with the outside of the piston 108. During operation, the movement of the piston grip 125 causes the piston 108 to move axially relative to the pump chamber 106 to control the receiving and delivery of fluid within the pump chamber 106. The piston grip 125 can be actuated by a variety of mechanisms and / or actuators. In various examples, the piston grip 125 can be actuated by an actuator capable of producing reciprocating motion, such actuators include, for example, piezoelectric-based actuators, solenoid-based actuators, nitinol-based actuators, spring-based actuators, rotary motors with gear trains, direct current (DC) motors, or any combination thereof. Using each of these examples, the desired effect of reciprocating fluid can be achieved.

[0021] In some embodiments, the piston grip 125 may comprise a grip body 127 extending from opposite sides of the piston 108. The grip body 127 may be a generally planar component and include one or more spring footers 128 extending therefrom. As shown, each spring footer 128 may comprise one or more tabs 171 for engaging with and holding a side spring 129 internally. In this embodiment, two side springs 129 may be positioned on opposite sides of the piston 108, parallel to a central axis extending through the piston 108, the pump chamber 106, and the detent body 116. However, in alternative embodiments, one spring may be used, with that spring aligned axially with the piston 108. The side springs 129 may provide spring force to bias the piston grip 125, and therefore the piston 108, toward the pump chamber 106, or, in other embodiments, toward the pump chamber 106.

[0022] As shown in Figure 2, in some embodiments, the pump 100 may include a first terminal 140 that is coupled to or part of the piston grip 125 or is movable with the piston 108. More specifically, the first terminal 140 may be a conductive plate (e.g., made of copper) coupled to a lower bridge 142 of the piston grip 125. The lower bridge 142 may extend to cover a second terminal 141, which may be a conductive plate (e.g., made of copper) coupled to or embedded in the PCB 143. In alternative embodiments, the first terminal 140 may be fixed to multiple different parts of the piston grip 125.

[0023] Figures 3A and 3B show simplified representations of the first terminal 140, the second terminal 141, and the substrate (e.g., PCB 143) in use. The first terminal 140 and the piston grip (not shown) can move back and forth between a first position shown in Figure 3A and a second position shown in Figure 3B. In some embodiments, the second terminal 141 has a variable shape (e.g., triangular), i.e., a variable shape that increases the capacitance between the first end 145 and the second end 146 of the second terminal 141 by increasing the overlapping surface area between the first terminal 140 and the second terminal 141. The separation distance (e.g., in the y-direction) between the first terminal 140 and the second terminal 141 can be selected to form a detectable range of capacitance. The separation distance is preferably between 50 and 200 microns, but is not limited to this. In some embodiments, if a larger capacitance is desired and additional friction does not affect the movement between the first terminal 140 and the second terminal 141, the substrate may be dielectric, and the space or gap "G" (Figure 3A) between the first terminal 140 and the second terminal 141 may be smaller.

[0024] Figure 4 is a schematic diagram of a sensor device 150 that can operate to detect a change in capacitance between a first terminal 140 and a second terminal 141 as the first terminal 140 and the second terminal 141 move relative to each other. As shown, the sensor device 150 may be a two-stage charging device including a first capacitor (CS) 151, a second capacitor 152 (CR), a first switch (SW1) 153, and a second switch 154 (SW2). The first capacitor 151 and the second capacitor 152 are connected on one side to a voltage source (VS) 156 and on the second side to a controller 155 which may be a microcontroller unit (MCU). The controller 155 may, but is not limited to, include a pulse width modulation (PWM) timer 158, an input / output driver or comparator input 159, and a counter 160. The first switch 153 may be placed between the first capacitor 151 and the voltage source 156, while the second switch 154 may be placed between the first capacitor 151 and the second capacitor 152.

[0025] During operation, the controller 155 can operate the first switch 153 and the second switch 154 to charge the voltage of the second capacitor 152. For example, for each filling and discharging cycle of the pump chamber 106, the controller 155 can connect the voltage source 156 to the first capacitor 151 to fully charge the first capacitor 151, and then open the first switch 153 and close the second switch 154 to equalize the voltage of the first capacitor 151 and the voltage of the second capacitor 152. The voltage of the second capacitor 152 may appear as a continuous charging curve showing an increase, as shown in Figure 5A. Figure 5B illustrates a charging curve over discrete time intervals. In some embodiments, this charging process may be viewed as a pumping process over discrete time intervals, and the rise in VR can be calculated according to Equation 1 below for each nth time interval from when VS was fully charged by the voltage source 156.

[0026]

number

[0027] In some embodiments, the measurement duration T meas This can be obtained by the controller 155 by counting the increment of the counter value from the start of charging of the VR until the VR reaches a specific threshold. This threshold may be either a digital I / O level "High" or a voltage trigger value set in the comparator input 159.

[0028] Figure 6 is a schematic diagram of a sensor device 250 that is operable to detect a change in capacitance between a first terminal and a second terminal as the first and second terminals move relative to each other. In this embodiment, a Kalman filter may be used to enable high-speed detection of charging / discharging of the first capacitor (Cs) 251 and / or the second capacitor 252 (Cr). As shown, the sensor device 250 may further include a first switch (SW1) 253 and a second switch 254 (SW2). The first capacitor 251 and the second capacitor 252 may be connected on one side to a voltage source (Vs) 256 and on the second side to a controller 255 which may be an MCU. The controller 255 may include, but is not limited to, a PWM timer 258, a PWM / IO 259, a counter 260, and an application delivery controller (ADC) 261. In some cases, the first switch 253 is positioned between the first capacitor 251 and the voltage source 256, while the second switch 254 is positioned between the first capacitor 251 and the second capacitor 252. In this embodiment, the sensor device 250 may further include a third switch (SW3) 263.

[0029] The second capacitor 252 can be continuously charged and discharged using a Kalman filter, with the first switch 253 used in the charging phase and the third switch 263 used in the discharging phase. When movement occurs between the first and / or second terminals, the capacitance of the first capacitor 251 changes abruptly, while the estimated capacitance Cs of the Kalman filter changes after a small number of samples have been read by the ADC. Thus, the movement of the piston grip can be captured by the sensor device 250 with minimal delay. In this alternative way, the delay in sensing movement (i.e., movement of the first and / or second terminals relative to each other) is minimized using a Kalman filter.

[0030] In some embodiments, the discharge of the second capacitor 252 may be unnecessary. Voltage (VR) curves are shown in Figures 7A and 7B, where Figure 7A shows the continuous charging / discharging of the first capacitor 251 without movement, and Figure 7B shows the continuous charging / discharging of the first capacitor when movement occurs during charging / discharging. When the mechanical movement of the terminals and the sensing of capacitance are not synchronized, this continuous operation enables the "immediate" detection of movement. Without this continuous operation, capacitance measurements would only be performed at regular intervals, which could lead to false detection of the discharge of the second capacitor 252. However, using a Kalman filter, the first capacitor 251 can be continuously charged and discharged.

[0031] Referring to Figure 8, a process 300 using a Kalman filter according to an embodiment of the present disclosure will be described in more detail. A Kalman filter is a time-domain filter that requires the minimum memory space to store historical data. The Kalman filter continuously estimates what the next voltage point and the actual capacitance value will be. In some embodiments, an extended Kalman filter (EKF) model is used. In this model, the Kalman filter algorithm is implemented in a design that simultaneously estimates parameters and system states using the estimated voltage charge value and the estimated capacitor value.

[0032] More specifically, in block 301, the initial prediction of the voltage (VR) at t-0 is performed according to the following formula.

[0033]

number

[0034] However, in some embodiments, the EKF results may not be sensitive to the initial estimates. In the following, X represents the variable or state to be estimated.

[0035]

number

[0036] In some embodiments where the simulation uses a 3pF capacitor in curve generation, the initial predicted value of CS for the first capacitor 251 is calculated according to the following formula:

[0037]

number

[0038] The initial estimates form a vector containing the estimated state VR and parameter CS, as shown below.

[0039]

number

[0040] In some embodiments, the initial estimates may also include the variances of the two variables. The covariance matrix P can be initialized as shown by the following formula.

[0041]

number

[0042] Next, in block 302, the following variable value (e.g., X) n and P n ) is predicted. In some embodiments, this estimation can be based on a system model such as the following:

[0043]

number

[0044] Based on the predicted values ​​of the state and parameters, the covariance matrix is ​​predicted as follows:

[0045]

number

[0046] In this example, F n-1 is the Jacobian matrix of the state / parameter transition matrix derived from equation 7, and Q is the covariance matrix of F. This prediction is the controller's "guess" about what the next state will be.

[0047] Next, in block 303, the predicted value is compared with the observed value, which is defined as follows.

[0048]

number

[0049] The superscript ADC indicates that the value is a reading from ADC261. In other embodiments, the observed value Z n Different methods can be employed to model this. After the observations are calculated, in block 304, the difference (i.e., the innovation vector) is calculated as follows:

[0050]

number

[0051] In block 305, the Kalman gain can be calculated as follows:

[0052]

number

[0053] In this example, H n This is the Jacobian matrix of the state observation vector (Equation 9). The estimated Kalman gain, "updated by observations," can be found as follows:

[0054]

number

[0055] Finally, the covariance matrix associated with the updated estimates is calculated as follows:

[0056]

number

[0057] In an alternative embodiment, process 300 can ignore the voltage estimation (Equation 2), use the ADC readings only for the observed values, and focus solely on estimating CS. This method would allow for faster convergence of the capacitance estimate.

[0058] In some embodiments, if the actual data for the algorithm is available from the MCU readout and the computation is performed within the MCU255, process 300 can be improved to a more stable implementation and faster convergence. The closer the model gets to the behavior of the actual system, the faster the algorithm converges.

[0059] Next, moving to Figure 9, another process 400 according to embodiments of the present disclosure is described. In block 401, this process may include positioning a first terminal adjacent to a second terminal, where the first and second terminals are movable relative to each other. In some embodiments, the first terminal is part of or coupled to a piston grip of a wearable drug delivery device. The second terminal may be part of a substrate (e.g., PCB) beneath the piston grip. In some embodiments, the second terminal is a conductive plate having a geometry that changes from a first end to a second end such that it forms a capacitance that changes correspondingly as the first and second terminals move relative to each other.

[0060] In block 402, process 400 may include detecting a change in capacitance between a first terminal and a second terminal using a sensor device, where the sensor device includes a two-stage charging device connected to a controller and a voltage source. In some embodiments, the sensor device may include a first capacitor, a second capacitor, a first switch, and a second switch. In some embodiments, the sensor device may include a third switch. The first and second capacitors may be connected to a voltage source on one side and to a controller, which may be a microcontroller unit, on the second side. The first switch may be located between the first capacitor and the voltage source, while the second switch may be located between the first and second capacitors. In some embodiments, a Kalman filter may be used to enable high-speed detection of charging / discharging of the first capacitor (Cs) and / or the second capacitor (Cr).

[0061] In block 403, process 400 may include charging the first capacitor by the controller by closing the first switch and connecting the first capacitor to a voltage source. In block 404, process 400 may include charging the second capacitor by the controller by opening the first switch and closing the second switch and connecting the second capacitor to a voltage source.

[0062] In some embodiments, process 400 may further include, for each pumping cycle, equalizing the first voltage of the first capacitor with the second voltage of the second capacitor by the controller. In some embodiments, process 400 may further include continuously charging and discharging the second capacitor using a Kalman filter. In some embodiments, continuously charging and discharging the second capacitor may include, by the controller, opening a third switch when the first capacitor is being charged, and by the controller closing the third switch when the first capacitor is being discharged.

[0063] Figure 10 shows a simplified block diagram of an exemplary system (hereinafter, "System") 500. System 500 may be a wearable or on-body drug delivery device and / or an analyte sensor attached to the skin of a patient 503. System 500 may comprise a controller 502, a pump mechanism 504 (hereinafter, "Pump 504"), and a sensor 508. Sensor 508 may be a glucose monitor or other analyte monitor, for example, a sustained glucose monitor. Furthermore, sensor 508 may be incorporated into the wearable device. Sensor 508 may be operable to, for example, measure the user's blood glucose (BG) level and generate a BG measurement level signal 512. The controller 502, pump 504, and sensor 508 may be coupled to communicate with each other via a wired or wireless communication path. For example, the controller 502, pump 504, and sensor 508 may each comprise a wireless high-frequency transceiver operable to communicate via one or more communication protocols such as Bluetooth®. System 500 may also include a delivery pump device 505, which is coupled to a reservoir 526 and includes a drive mechanism for dispensing a liquid drug 525 therefrom. In some embodiments, the drive mechanism 506 may include a first terminal 540 coupled to or part of a piston grip 535. In some embodiments, the first terminal 540 may be a conductive plate (e.g., made of copper) coupled to a lower bridge of the piston grip 535. The lower bridge may extend to cover a second terminal 541, which may be a conductive plate (e.g., made of copper) coupled to or embedded in a PCB (not shown). System 500 may include additional components not shown and described for brevity.

[0064] Controller 502 may receive a BG desired level signal, which may be a first signal indicating a desired BG level or range for patient 503. The BG desired level signal may be stored in the memory of controller 509 on device 505, received through a user interface to controller 502 or other devices, or received by an algorithm in controller 509 (or controller 502) that automatically determines the BG level for patient 503. Sensor 508 may be coupled to patient 503 and operable to measure an approximate value of patient 503's BG level. Depending on the BG measurement level or measurement, sensor 508 may generate a signal indicating the BG measurement. As shown, controller 502 may also receive a BG measurement level signal 512 from sensor 508 via a communication path, which may be a second signal.

[0065] Based on the BG desired level signal and the BG measured level signal 512, controller 502 or controller 509 may generate one or more control signals to direct the operation of pump 504. For example, one control signal 519 from controller 502 or controller 509 may cause pump 504 to start or activate one or more power elements 523 operably connected to the device 505. A specified amount of liquid medication 525 may determine the approximate amount of insulin needed to move the user's BG measured level to the BG desired level. Based on the operation of pump 504, patient 503 may receive the liquid medication from reservoir 526 as determined by the control signal 519. System 500 may operate as a closed-loop system, an open-loop system, or a hybrid system. In an exemplary closed-loop system, controller 509 can direct the operation of device 505 without input from controller 502 and can receive the BG level signal 512 from sensor 508. The sensor 508 may be stored within the device 505, or it may be stored in a separate device and communicate directly with the device 505 wirelessly.

[0066] As further illustrated, the system 500 may include a needle deployment element 528 that communicates with a controller 502 or controller 509. This needle deployment element 528 may have a needle / cannula 529 that can be deployed into the body of the patient 503 and has one or more holes at its distal end. The device 505 may be connected to the needle / cannula 529 by a fluid pathway element 530. The fluid pathway element 530 may be of any size and shape and may be made from any suitable material. The fluid pathway element 530 may allow a fluid, such as a liquid drug 525 in a reservoir 526, to be delivered to the needle / cannula 529.

[0067] The controller 502 / 509 can be implemented in hardware, software, or any combination thereof. The controller 502 / 509 may be, for example, a microcontroller coupled to a processor, logic circuit, or memory. The controller 502 / 509 can maintain the date and time, as well as other functions (such as calculations) performed by the processor. The controller 502 / 509 may be operable to execute an artificial pancreas (AP) algorithm stored in memory (not shown) so that the controller 502 / 509 can direct the operation of the pump 504. For example, the controller 502 / 509 may be operable to receive input from sensor 508, which indicates the settings for an automated insulin delivery (AID) application. Based on the AID application settings, the controller 502 / 509 may modify the behavior of the pump 504 so that the liquid medication 525 is delivered to the patient 503 via the device 505.

[0068] In some embodiments, the controller 502 / 509 may operate together with a sensor device 550, which may be the same as or similar to the sensor device 150 or sensor device 250 described above. The sensor device 550 may be part of the device 505 as shown in the figure, or it may be located outside of the device 505. In some embodiments, the sensor device 550 may be a two-stage charging device comprising a first capacitor 551 and a second capacitor 552. The first capacitor 551 and the second capacitor 552 may be connected on one side to a voltage source such as a power element 523 and on the second side to the controller 502 / 509. During use, the controller 502 / 509 can operate the first and second switches of the sensor device 550 to charge the voltage of the second capacitor 552. For example, for each of the pump chamber filling and discharging cycles, the controller 502 / 509 may connect a voltage source to the first capacitor 551 to fully charge the first capacitor 551, and then equalize the voltages of the first capacitor 551 and the second capacitor 552 by opening the first switch and closing the second switch. The voltage of the second capacitor 552 may appear as an increasing, continuous charging curve.

[0069] In some embodiments, the second capacitor 552 can be continuously charged and discharged using a Kalman filter, with the first switch used in the charging phase and the third switch used in the discharging phase. When movement occurs at the first terminal 540 and / or the second terminal 541, the capacitance of the first capacitor 551 changes abruptly, while the estimated capacitance in the Kalman filter changes after a small number of samples have been read in the ADC of the controller 502 / 509. Thus, the movement of the piston grip 535 can be captured by the sensor device 550 with minimal delay (e.g., 100-400 μs). In this alternative method, the delay from the start of movement to the sensing of the movement is minimized using a Kalman filter.

[0070] In some embodiments, the sensor 508 may be, for example, a continuous glucose monitor (CGM). The sensor 508 may be physically separate from the pump 504 or it may be an integrated component within the same housing. The sensor 508 may provide the controller 502 with data indicating the measured or detected value of the user's blood glucose level.

[0071] The power element 523 may be a battery, piezoelectric device, or the like, for supplying power to the device 505. In other embodiments, the power element 523 or an additional power source (not shown) may also supply power to other components of the pump 504, which may be, for example, a controller 502, memory, sensor 508, and / or needle deployment element 528.

[0072] In one example, the sensor 508 is a device communicatively coupled to the controller 502 and may be capable of measuring blood glucose levels at predetermined time intervals, such as every 5 or 10 minutes. The sensor 508 can provide a number of blood glucose measurements to the AP application.

[0073] In some embodiments, when the pump 504 is in a normal operating mode, it delivers insulin stored in the reservoir 526 to the patient 503 based on information provided by the sensor 508 or other functional elements of the pump 504 (e.g., blood glucose measurement, blood glucose target value, insulin onboard, previous insulin delivery, time, day of the week, input values ​​from the inertial measurement unit, GPS system available device, Wi-Fi available device, etc.). For example, the pump 504 may include analog and / or digital circuitry that can be implemented as a controller 502 / 509 for controlling the delivery of a drug or therapeutic agent. The circuitry used to implement the controller 502 / 509 may include discrete, specialized logic and / or components, application-specific integrated circuits, microcontrollers or processors that execute software instructions, firmware, activation of programming code such as programming instructions or AP applications stored in memory, or any combination thereof. For example, controller 502 / 509 may execute control algorithms and other programming code that enable it to deliver a dose of drug or therapeutic agent to the user at predetermined time intervals, or as needed, in order to bring the blood glucose measurement to the blood glucose target. The size and / or timing of basal and bolus doses may be determined automatically based on information (e.g., blood glucose measurement, blood glucose target, insulin onboard, previous insulin delivery, time, day of the week, input from inertial measurement unit, GPS system available device, Wi-Fi available device, etc.), or may be pre-programmed by the patient 503 or a third party (e.g., healthcare provider, parent or guardian, manufacturer of wearable drug delivery device, etc.) using a wired or wireless link, for example, within an AP application.

[0074] Although not shown in the figures, in some embodiments the sensor 508 may include a processor, memory, sensing or measuring device, and communication device. The memory may be capable of storing instances of the AP application and other programming code, and may be operable to store data related to the AP application.

[0075] In various embodiments, the sensing / measuring device of sensor 508 may include one or more sensing elements such as a blood glucose measuring element, a heart rate monitor, and a blood oxygen sensor element. The sensor processor may include discrete, specialized logic and / or components, application-specific integrated circuits, a microcontroller or processor that executes software instructions, firmware, programming instructions stored in memory, or any combination thereof.

[0076] The above discussion is presented for illustrative and explanatory purposes only and is not intended to limit the disclosure to the forms described herein. For example, various features of the disclosure may be combined and integrated into one or more aspects, embodiments, or configurations for the purpose of streamlining the disclosure. However, it should be understood that various features of particular aspects, embodiments, or configurations of the disclosure may be combined to form alternative aspects, embodiments, or configurations.

[0077] It should be understood that, when used herein, elements or steps described in the singular form preceded by "a" or "an" do not exclude the plural nature of the element or step, unless such exclusion is explicitly stated. Furthermore, the references to “one embodiment” in this disclosure are not intended to be construed as excluding the existence of additional embodiments incorporating the described features.

[0078] In this specification, the use of “includes,” “equips,” or “possesses,” and their variations, means to include the items listed thereafter, their equivalents, and additional items. Therefore, the words “includes,” “equips,” or “possesses,” and their variations, are open-ended expressions and may be used interchangeably in this specification.

[0079] As used herein, the phrases “at least one,” “one or more,” and “and / or” are open-ended expressions that are both joint and separate in use. For example, “at least one of A, B, and C,” “at least one of A, B, or C,” “one or more of A, B, and C,” “one or more of A, B, or C,” and “A, B, and / or C” mean A only, B only, C only, A and B, A and C, B and C, or A, B and C, respectively.

[0080] All descriptions of direction (e.g., proximal, distal, superior, inferior, upward, downward, left, right, lateral, longitudinal, front, back, top, bottom, up, down, vertical, horizontal, radial, axial, clockwise, and counterclockwise) are used solely for identification purposes to help the reader understand this disclosure and do not create any limitation of this disclosure, particularly regarding its location, orientation, or use. Descriptions of connections (e.g., attached, joined, connected, and joined) should be interpreted broadly and, unless otherwise suggested, may include intermediate members between assembled elements or relative movement between elements. Thus, descriptions of connections do not necessarily suggest that two elements are directly connected and have a fixed relationship with respect to one another.

[0081] Furthermore, identifying designations (e.g., primary, secondary, first, second, third, fourth) are not intended to suggest importance or priority, but are used to distinguish one element from another. The drawings are for illustrative purposes only, and the dimensions, locations, order, and relative sizes reflected in the drawings attached to this specification are subject to change.

[0082] Furthermore, in some embodiments, the terms “substantial” or “substantially” can be used interchangeably with the terms “approximately” or “generally,” and can be described using relevant measurements acceptable to those skilled in the art. For example, these terms can function as a comparison with a reference parameter and can suggest a deviation that can provide the intended function. Deviations from the reference parameter may include, but are not limited to, quantities such as less than 1%, less than 3%, less than 5%, less than 10%, less than 15%, or less than 20%.

[0083] Furthermore, although the various methods disclosed herein are described as a series of actions or events, this disclosure is not limited to the described order of such actions or events unless otherwise specified. According to this disclosure, for example, some actions may occur in a different order than described and / or described herein, and / or simultaneously with other actions or events. In addition, according to this disclosure, not all described actions or events may be necessary to implement the methodology. Furthermore, this method may be implemented in connection with the formation and / or processing of structures described and described herein, and similarly, it may be implemented in connection with other structures not described herein.

[0084] This disclosure should not be limited in scope by the specific embodiments described herein. In fact, a person skilled in the art will see from the foregoing description and accompanying drawings that various other embodiments and modifications of this disclosure, in addition to those described herein, are evident. Thus, such other embodiments and modifications are intended to fall within the scope of this disclosure. Furthermore, this disclosure is described herein for a particular purpose, in a particular environment, and in the context of a particular implementation. A person skilled in the art will recognize that its usefulness is not limited thereto, and that this disclosure can be implemented to benefit many purposes and in many environments. Thus, the claims described below should be interpreted in light of the full breadth and spirit of this disclosure as described herein. Furthermore, this disclosure includes the following aspects: [Aspect 1] A system, wherein the system is A first terminal and a second terminal that are movable relative to each other, The system includes a sensor device that is operable to detect a change in capacitance between the first terminal and the second terminal when the first terminal and the second terminal move relative to each other, wherein the sensor device is The device includes a controller and a two-stage charging device connected to a voltage source, the two-stage charging device comprising a first capacitor connected to a first switch and a second capacitor connected to a second switch, and the controller is Close the first switch and connect the first capacitor to the voltage source to charge the first capacitor, and, A system that is operable to open the first switch and close the second switch to connect the second capacitor to the voltage source and charge the second capacitor. [Aspect 2] The system according to embodiment 1, wherein the controller is operable to make the first voltage of the first capacitor equal to the second voltage of the second capacitor for each cycle. [Aspect 3] The system according to embodiment 1, wherein the controller is capable of operating to continuously charge and discharge the second capacitor while using a Kalman filter. [Aspect 4] The system according to embodiment 3, wherein the two-stage charging device is equipped with a third switch, and the controller is operable to open the third switch when the first capacitor is being charged and to close the third switch when the first capacitor is being discharged. [Aspect 5] The system according to embodiment 1, further comprising a pump mechanism having a movable piston, wherein the first terminal is connected to the piston. [Aspect 6] The system according to embodiment 5, wherein the second terminal is a conductive element, and the conductive element is coupled to a dielectric material. [Aspect 7] The system according to embodiment 6, wherein the dielectric material is a printed circuit board. [Aspect 8] The system according to embodiment 6, wherein the conductive element has a variable shape such that the capacitance between the conductive element and the first terminal increases between the first and second ends of the conductive element. [Aspect 9] A linear shuttle type pump, wherein the linear shuttle type pump is The linear shuttle pump comprises a first terminal and a second terminal that are movable relative to each other, the first terminal being part of a pump mechanism, and the linear shuttle pump further comprises The system includes a sensor device that is operable to detect a change in capacitance between the first terminal and the second terminal as the first terminal and the second terminal move relative to each other, and the sensor device is The device includes a controller and a two-stage charging device connected to a voltage source, the two-stage charging device comprising a first capacitor connected to a first switch and a second capacitor connected to a second switch, and the controller is Close the first switch and connect the first capacitor to the voltage source to charge the first capacitor, and, A linear shuttle pump that is operable to open the first switch and close the second switch to connect the second capacitor to the voltage source and charge the second capacitor. [Aspect 10] The linear shuttle pump according to embodiment 9, wherein the controller is operable to make the first voltage of the first capacitor equal to the second voltage of the second capacitor for each pumping cycle. [Aspect 11] The linear shuttle pump according to embodiment 9, wherein the controller is capable of operating to continuously charge and discharge the second capacitor using a Kalman filter. [Aspect 12] The linear shuttle pump according to embodiment 11, wherein the two-stage charging device is equipped with a third switch, and the controller is operable to open the third switch when the first capacitor is being charged and to close the third switch when the first capacitor is being discharged. [Aspect 13] The linear shuttle pump according to embodiment 9, wherein the pump mechanism is equipped with a piston grip, and the first terminal is part of the piston grip. [Aspect 14] The linear shuttle pump according to embodiment 9, wherein the second terminal is a conductive element, and the conductive element has a variable shape such that the capacitance between the conductive element and the first terminal increases between the first and second ends of the conductive element. [Aspect 15] A method, wherein the said method is Positioning a first terminal so that it is adjacent to a second terminal, wherein the first terminal and the second terminal are movable relative to each other. The method involves detecting a change in capacitance between the first terminal and the second terminal using a sensor device, wherein the sensor device includes a two-stage charging device connected to a controller and a voltage source. The controller charges the first capacitor by closing the first switch and connecting the first capacitor to the voltage source, A method comprising charging the second capacitor by connecting the second capacitor to the voltage source by opening the first switch and closing the second switch using the controller. [Aspect 16] The method according to embodiment 15, further comprising, for each pumping cycle, the controller making the first voltage of the first capacitor equal to the second voltage of the second capacitor. [Aspect 17] The method according to embodiment 15, further comprising continuously charging and discharging the second capacitor while using a Kalman filter. [Aspect 18] Continuously charging and discharging the second capacitor is, The controller opens the third switch when the first capacitor is charged, The method according to embodiment 17, further comprising opening the third switch by the controller when the first capacitor is being discharged. [Aspect 19] The method further comprises providing a pump mechanism having a piston grip, wherein the first terminal is part of the piston grip, according to embodiment 15. [Aspect 20] The method according to embodiment 15, further comprising changing the shape of the second terminal such that the capacitance between the first terminal and the second terminal increases between the first and second ends of the second terminal.

Claims

1. A system, wherein the system is A first terminal and a second terminal that are movable relative to each other, A pump mechanism having a movable piston, wherein the first terminal is connected to the piston or is part of the piston grip, The system includes a sensor device that is operable to detect a change in capacitance between the first terminal and the second terminal when the first terminal and the second terminal move relative to each other, and the sensor device is The system includes a controller and a two-stage charging device connected to a voltage source, the two-stage charging device comprising a first capacitor connected to a first switch and a second capacitor connected to a second switch, and the controller, Close the first switch and connect the first capacitor to the voltage source to charge the first capacitor, and, A system that is operable to open the first switch and close the second switch to connect the second capacitor to the voltage source and charge the second capacitor.

2. The system according to claim 1, wherein the controller is operable to make the first voltage of the first capacitor equal to the second voltage of the second capacitor for each of the pump chamber filling and discharging cycles.

3. The system according to claim 1, wherein the controller is capable of operating to continuously charge and discharge the second capacitor while using a Kalman filter.

4. The system according to claim 3, wherein the two-stage charging device is equipped with a third switch, and the controller is operable to open the third switch when the first capacitor is being charged and to close the third switch when the first capacitor is being discharged.

5. The system according to claim 1, wherein the second terminal is a conductive element, and the conductive element is bonded to a dielectric material.

6. The system according to claim 5, wherein the dielectric material is a printed circuit board.

7. The system according to claim 5, wherein the conductive element has a variable shape such that the capacitance between the conductive element and the first terminal increases between the first and second ends of the conductive element.

8. The system according to any one of claims 1 to 7, wherein the pump mechanism is provided within a linear shuttle pump.

9. A method, wherein the said method is Positioning a first terminal adjacent to a second terminal in a pump mechanism having a movable piston, wherein the first terminal is connected to the piston or is part of the piston grip, and the first terminal and the second terminal are movable relative to each other. The method involves detecting a change in capacitance between the first terminal and the second terminal using a sensor device, wherein the sensor device includes a two-stage charging device connected to a controller and a voltage source. The controller charges the first capacitor by closing the first switch and connecting the first capacitor to the voltage source, A method comprising charging the second capacitor by connecting the second capacitor to the voltage source, by opening the first switch and closing the second switch using the controller.

10. The method according to claim 9, further comprising, for each of the pump chamber filling and discharge cycles, the controller making the first voltage of the first capacitor equal to the second voltage of the second capacitor.

11. The method according to claim 9, further comprising continuously charging and discharging the second capacitor while using a Kalman filter.

12. Continuously charging and discharging the second capacitor is, The controller opens the third switch when the first capacitor is charged, The method according to claim 11, further comprising closing the third switch by the controller when the first capacitor is being discharged.

13. The method according to claim 9, further comprising changing the shape of the second terminal such that the capacitance between the first terminal and the second terminal increases between the first and second ends of the second terminal.

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