Single actuation high-precision dose intermediate pumping chamber

Abstract

Examples of devices, systems and techniques for dispensing a liquid agent are disclosed. An exemplary dispensing pump device may include a chamber body forming a pump chamber, an inlet valve for receiving the liquid agent, and a hard stop. A plunger is configured with a plunger channel. A sliding fluid member includes a needle coupling, a flow port, a face seal, and an anchor portion that may be movable within the pump chamber. A pump mechanism may be coupled to the anchor portion and operable to pull the anchor portion and the plunger toward the hard stop. The technique includes determining a time to output the liquid agent from the dispensing pump device, generating a control signal to operate the dispensing pump device, applying the control signal to the pump mechanism, determining that the control signal should be removed from the pump mechanism, and dispensing the liquid agent.

Description

[Technical field]

[0001] Related Applications This application claims the benefit of U.S. Provisional Patent Application No. 63 / 135,081, filed January 8, 2021, the entire contents of which are incorporated herein by reference.

[0002] The disclosed examples relate generally to the delivery of medicaments. More specifically, the disclosed examples relate to techniques, processes, systems and pump devices for providing a measured amount of fluid that is delivered and refilled within a single pumping cycle. [Background technology]

[0003] Many drug ejection devices include a reservoir for storing the liquid medication and a pump mechanism operable to expel the stored liquid medication from the reservoir for delivery to a user. The pump mechanism may be a positive displacement pump that expels a dose of medication from the reservoir to a patient through valving or reciprocating motion. Other conventional pumps include, but are not limited to, diaphragm pumps, rotary pumps, vane pumps, screw / turbine pumps, or other types of conventional pumps. Some conventional drive mechanisms use a plunger to expel the liquid medication from the reservoir, which may result in the length of the drive mechanism being roughly the same as the length of the reservoir. Summary of the Invention [Problem to be solved by the invention]

[0004] Various pump mechanism configurations may result in an apparent under- or over-dose of liquid medication being delivered over time due to mechanical "sticking" or "slippage" of the pump mechanism.

[0005] Therefore, there is a need for a simplified system for accurately dispensing the liquid medication from the reservoir, which also reduces the overall size of the medication ejection device. [Means for solving the problem]

[0006] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to aid in determining the scope of the claimed subject matter.

[0007] Some proposals disclose a wearable drug ejection device comprising a tank and an ejection pump device. The tank may be configured to store a liquid drug. The ejection pump device may be coupled to the tank to receive the liquid drug from the tank. The ejection pump device may comprise a chamber body forming a pump chamber, an inlet port configured to allow the liquid drug from the tank to be drawn into the pump chamber, a sliding fluid member with a flow port and a fluid path to the needle, a plunger including a plunger channel configured to engage with the sliding fluid member, and a shape memory alloy wire coupled to the sliding fluid member. The shape memory alloy wire is operable to draw the liquid drug from the tank through the inlet port into the pump chamber by pulling the sliding fluid member and the plunger in a first direction. The sliding fluid member is configured to allow the liquid drug to be drawn into the pump chamber and discharged into the fluid path from the pump chamber to the needle for output.

[0008] In another aspect, an ejection pump device for a wearable drug ejection device is provided. The ejection pump device comprises a chamber body, a plunger, a sliding fluid member, and a shape memory alloy. The chamber body defines a pump chamber, comprises a hard stop and an inlet valve, and is operable to receive a liquid drug from a tank. The plunger is movable within the pump chamber of the chamber body and may comprise a plunger channel. The sliding fluid member is movable within the pump chamber and may comprise a needle coupling, a flow port, a face seal, and an anchor portion. The anchor portion is positioned and movable within the plunger channel in a leak-tight configuration. A shape memory alloy wire may be coupled to the anchor portion. The shape memory alloy wire is operable to pull the anchor portion and the plunger toward the hard stop.

[0009] In an additional aspect, a method of controlling a dispensing pump device to output a liquid agent is disclosed. The method includes determining a time to output the liquid agent from the dispensing pump device. A control signal may be generated to operate the dispensing pump device. The control signal may be applied to a pump mechanism of the dispensing pump device. The pump mechanism comprises a shape memory alloy wire configured to respond to the applied control signal. When a pump chamber of the dispensing pump device is filled with the liquid agent, it is determined that the applied control signal should be removed from the pump mechanism of the dispensing pump device. The applied control signal may be removed from the pump mechanism to allow the liquid agent to be dispensed from the pump chamber. Dispensing of the liquid agent may be confirmed.

[0010] In the drawings, like reference numbers generally refer to the same parts throughout the different views. In the following description, various examples of the present disclosure are described with reference to the following drawings, in which: [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 shows a schematic diagram of a medication ejection system according to an example of the present disclosure.

[0012] [Diagram 2]FIG. 2 shows a cross-sectional side view of the intermediate pumping chamber of the discharge pump arrangement at the beginning of a pumping cycle.

[0013] [Figure 3A] FIG. 3A illustrates a cross-sectional side view of the intermediate pumping chamber of the discharge pumping apparatus during transition from an initial state of a pumping cycle of the intermediate pumping chamber shown in the example of FIG.

[0014] [Figure 3B] FIG. 3B illustrates an exemplary filling area of ​​an exemplary pump chamber of an intermediate pumping chamber.

[0015] [Figure 4] FIG. 4 illustrates a cross-sectional view of an exemplary intermediate pumping chamber in a filled state prior to expelling a liquid agent from the pump chamber.

[0016] [Diagram 5] FIG. 5 illustrates a cross-sectional view of an exemplary intermediate pumping chamber transitioning from the fill state to the ready to dispense state of the example of FIG.

[0017] [Figure 6] FIG. 6 illustrates a cross-sectional view of an exemplary intermediate pumping chamber that initiates the ejection of a liquid agent from the pump chamber.

[0018] [Figure 7] FIG. 7 illustrates a cross-sectional view of an exemplary intermediate pumping chamber with a liquid agent being expelled from the pump chamber by movement of the plunger.

[0019] [Figure 8] FIG. 8 shows a cross-sectional view of another exemplary configuration of the intermediate pumping chamber.

[0020] [Figure 9] FIG. 9 illustrates a cross-sectional side view of the intermediate pumping chamber of the discharge pumping apparatus during transition from the initial state of the intermediate pumping chamber pumping cycle shown in the example of FIG.

[0021] [Figure 10] FIG. 10 shows a side cross-sectional view of the intermediate pumping chamber in the example of FIG. 9 in a filled state prior to expelling liquid agent from the pump chamber.

[0022] [Figure 11] FIG. 11 illustrates a cross-sectional view of an exemplary intermediate pumping chamber transitioning from the filling state of the example of FIG. 4 to the expelling state due to movement of the plunger expelling liquid drug from the pump chamber.

[0023] [Figure 12] FIG. 12 illustrates example configurations of electrical contacts for various control aspects of an example discharge pump device.

[0024] [Figure 13] FIG. 13 is a flow chart of a process that may utilize the example of FIGS. 1-12 for expelling a drug from a dispensing pump device.

[0025] The drawings are not necessarily to scale. The drawings are merely representational and are not intended to portray specific parameters of the present disclosure. The drawings are intended to illustrate examples of the present disclosure and are not to be considered limiting in scope. Furthermore, certain elements in some of the figures may be omitted or not drawn to scale for clarity of illustration. Furthermore, some reference numbers may be omitted in certain figures for clarity. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] The systems, devices, and methods according to the present disclosure will now be more generally described below with reference to the accompanying drawings, in which one or more examples are shown. The systems, devices, and methods may be embodied in many different forms and should not be construed as being limited to the examples set forth herein. Instead, such examples are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the methods and devices to those skilled in the art. Each of the systems, devices, and methods disclosed herein provides one or more advantages over conventional systems, components, and methods.

[0027] The pump mechanism described herein is intended to have the above advantageous properties. Moreover, the pump mechanism is configured to output a set amount of liquid medicament during each "pulse" of the pump. This assumes that the moving members of the pump mechanism move from their respective "start" ends to their respective "stop" ends. The distance traveled by the pump mechanism may be referred to as a "pump stroke", and the distance traveled may be variable. In some examples, the pump stroke may be an adjustable or pre-set distance. A "pulse" may be considered as an actuation of the pump in response to a control signal, during which a dose of liquid medicament is output from a reservoir of the wearable drug delivery device.

[0028] 1 shows a simplified block diagram of an exemplary system 100. System 100 may be a wearable, i.e., body-worn, drug delivery device configured to be attached to the skin of a patient 103. System 100 may include a controller 102, a pump mechanism 104 (also referred to as “pump 104”), and a sensor 108.

[0029] The sensor 108 may be an analyte sensor operable to detect ketones, lactate, uric acid, alcohol, glucose, and the like. For example, the sensor 108 may be a glucose monitor, such as, for example, a continuous glucose monitor. The sensor 108 may be operable, for example, to measure a blood glucose (BG) level of a user to generate a measured BG level signal 112. The controller 102, the pump 104, and the sensor 108 may be communicatively coupled to one another via wired or wireless communication paths. For example, the controller 102, the pump 104, and the sensor 108 may each be equipped with a wireless radio frequency transceiver operable to communicate via one or more communication protocols, such as Bluetooth®. As described in more detail herein, the system 100 may also include a discharge pump device (also referred to as a “device”) 105 including a housing 114 forming an intermediate pumping chamber 115, an inlet port 116, and an outlet port 117. The system 100 may include additional components not shown or described for the sake of brevity.

[0030] In one example, the controller 102 may receive a desired BG level signal indicative of a desired BG level or BG range for the patient 103. The desired BG level signal may be received, for example, from a user interface (not shown) to the controller 102 or another device, or by an algorithm that automatically determines an ideal BG level for the patient 103. The sensor 108 may be coupled to the patient 103 and operable to measure an approximation of the user's BG level. In response to the measured BG level or value, the sensor 108 may generate a signal indicative of the measured BG value. As shown in this example, the controller 102 may also receive a measured BG level signal 112 from the sensor 108 via a communication path.

[0031] Based on the desired BG level signal and the measured BG level signal 112, the controller 102 may generate one or more control signals to direct the operation of the pump 104. For example, one control signal 119 from the controller 102 may activate or actuate one or more power elements 123 operatively connected to the device 105. As described with reference to the example of FIGS. 2-13, the power elements 123 may actuate an SMA wire (not shown in this example) in the intermediate pumping chamber 115. In response, the SMA wire may change shape and / or length, thereby changing the configuration of the intermediate pumping chamber 115.

[0032] In response to a change in pressure due to a change in the configuration of the intermediate pumping chamber 115, a quantity of liquid medication 125 (e.g., insulin) may be drawn into the intermediate pumping chamber 115 through the inlet port 116. For example, the quantity of liquid medication 125 may be determined based on a difference between a desired BG level signal and an actual BG signal level 112. The quantity of liquid medication 125 may be determined as an appropriate amount of insulin to bring the user's measured BG level to the desired BG level. Based on the operation of the pump 104 as determined by the control signal 119, the patient 103 may receive liquid medication from the reservoir 126 through a series of pulses. The system 100 may operate as a closed loop system, an open loop system, or a hybrid system.

[0033] As further shown, the system 100 may include a needle placement component 128 in communication with the controller 102. The needle placement component 128 may include a needle / cannula 129 positionable within the patient 103. The cannula 129 may form part of a fluid pathway coupling the patient 103 to the reservoir 126.

[0034] As further shown, the outlet port 117 may be coupled to a cannula 129. The intermediate pumping chamber 115 is coupled to a needle / cannula fitting (shown in another figure) that allows fluid from the reservoir 126 to be transferred via the outlet port 117 to the cannula 129. The cannula 129 may be configured to allow fluid being ejected from the device 105 to be provided to the patient 103.

[0035] The controller 102 may be implemented in hardware, software, or any combination thereof. The controller 102 may be, for example, a processor, logic circuit, or microcontroller coupled to a memory 106. The memory 106 may include a logic circuit 106-1 and a regulator 106-2. The controller 102 may maintain a date and time, and perform various functions (e.g., calculations, etc.) that can be used to determine the status or state of various components of the system. The controller 102 may be operable to execute algorithms, such as an artificial pancreas (AP) algorithm, stored in the memory 106 as a logic circuit 106-1 that may be operable to enable the controller 102 to direct the operation of the pump 104. The logic circuit 106-1 may enable the operation of the delivery device 105. For example, the controller 102 may be operable to receive inputs from a sensor 108, which correspond to application settings that the controller 102 may utilize to control the intermediate pumping chamber 115, such as automatic drug delivery, such as automatic insulin delivery (AID). The controller 102 may alter the behavior of the pump 104 and, consequently, the amount of liquid medication 125 delivered to the patient 103 via the device 105 based on the AID application settings.

[0036] In some examples, the sensor 108 may be, for example, a continuous glucose monitor (CGM). The sensor 108 may be physically separate from the pump 104 or may be an integrated component within the same or adjacent housing as the pump 104. The sensor 108 may provide data to the controller 102 indicative of the user's measured or detected blood glucose level.

[0037] The power element 123 may be a battery, a piezoelectric device, etc., for powering the device 105. In other examples, the power element 123 or an additional power source (not shown) may also provide power to other components of the pump 104, such as the controller 102, the memory 106, the sensor 108, and / or the needle positioning component 128.

[0038] In one example, the sensor 108 may be a device communicatively coupled to the controller 102 and may be operable to measure blood glucose levels at predetermined time intervals, such as approximately every 5 minutes, every 10 minutes, etc. The sensor 108 may provide multiple blood glucose measurements to an AP application executed by the controller 102 or an external controller.

[0039] In some examples, when operating in a normal operating mode, the pump 104 provides insulin stored in the reservoir 126 to the patient 103 based on information provided by the sensor 108 or other functional elements of the pump 104 (e.g., blood glucose measurements, blood glucose target values, on-board insulin, previous insulin doses, time of day, day of the week, input from an inertial measurement unit, global positioning system enabled device, Wi-Fi enabled device, etc.). For example, the pump 104 may include analog and / or digital circuitry that may be implemented as a controller 102 for controlling the delivery of a drug or therapeutic agent. The circuitry used to implement the controller 102 may include separate specialized logic circuits and / or components, application specific integrated circuits, a microcontroller or processor executing software instructions, firmware, e.g., programming instructions or programming code stored in the memory 106 to enable an AP application, or any combination thereof. For example, the controller 102 may execute programming code, including control algorithms, such as an AP application, to operate the controller 102 to deliver doses of a drug or therapeutic agent to the user at predetermined intervals or as needed to bring the blood glucose reading to a target blood glucose level or range. The dose size and / or timing may be preprogrammed, for example, into the AP application by the patient 103 or a third party (such as a healthcare provider, a parent or guardian, a manufacturer of the wearable drug delivery device, etc.) using a wired or wireless link. The AP application may also be executable to automatically adjust any settings that may be preprogrammed (such as insulin dose limits, number of delivered strokes or pulses, etc.) based on data received from the sensor 108 or a detector (shown in another figure) in the intermediate pumping chamber 115. The controller 102 may be coupled to the intermediate pumping chamber 115 via a communication path 188. The controller 102 may send control signals to components (shown in other examples) of the intermediate pumping chamber 115.

[0040] Although not shown, in some examples, the sensor 108 may include a processor, a memory, a sensing or measuring device, and a communication device (not shown in this example). The memory may store instances of AP applications as well as other programming code and may be operable to store data related to the AP applications.

[0041] In various examples, the sensing / measurement device of the sensor 108 may include one or more sensing elements such as a blood glucose measuring element, a heart rate monitor, a blood oxygen sensor element, etc. In one example, the sensor processor may include separate specialized logic circuits and / or components, an application specific integrated circuit, a microcontroller or processor that executes software instructions, firmware, programming instructions stored in a memory, or any combination thereof.

[0042] FIG. 2 illustrates a side cross-sectional view of an intermediate pumping chamber of the example wearable drug ejection system of FIG. 1 in an initial position. The intermediate pumping chamber 200 may have a front portion 200a and a rear portion 200b, and may be coupled to a tank containing a liquid drug via a tank coupling 201. The intermediate pumping chamber 200 may be operable to change configuration during operation. For example, the initial position of FIG. 2 may be a position where no liquid drug is being drawn from the tank into the pump chamber (shown in more detail in another figure). Components of the exemplary intermediate pumping chamber 200 may include a sliding fluid member 1, a chamber body 10, and a plunger 3. Additional components may include a valve 2, such as a passive check valve, a plunger spring 4, a fluid member (FM) spring 5, a shape memory alloy (SMA) wire 6, a hard stop 7, and a face seal 11. The inlet port 116 of FIG. 1 may be formed by a passive check valve 2 and may be configured to allow the liquid drug to be drawn from the tank into the pump chamber (shown in more detail in another figure). The plunger spring 4 and the FM spring 5 may be compression springs. The FM spring 5 and the plunger spring 4 are shown in their respective rest positions when the intermediate pumping chamber 200 is in this initial position (FIG. 2). Of course, other types of springs or other types of devices may be used in place of the springs in the exemplary intermediate pumping chamber 200.

[0043] In this example, the position of the sliding fluid member 1 as shown in FIG. 2 may be considered as a rest or initial position. The sliding fluid member 1 may be configured with an anchor portion 1a, a needle / cannula fitting 1b and a flow port 12. The needle / cannula fitting 1b may be configured as a hollow member, for example, to provide a fluid path 16 to a needle / cannula (not shown in this example). The sliding fluid member 1 may be configured with a flow port 12 integrated into the sliding fluid member 1 between the anchor portion 1a and the needle / cannula fitting 1b. For example, the sliding fluid member 1 may be configured with the flow port 12 and a fluid path 16 to the needle. The sliding fluid member 1 may be coupled to a needle or cannula, such as 129 in FIG. 1. The anchor portion 1a may be configured with a structure (not shown in this example for ease of illustration) that connects the anchor portion 1a to the needle / cannula fitting 1b. Needle / cannula fitting 1b may be configured to remain coupled to a needle / cannula (not shown in this example) and extend into chamber body 10. For example, needle / cannula fitting 1b may be a resilient member, a leak-proof, multi-part expandable tube, or a combination thereof. Flow port 12 may be surrounded by structure that couples needle / cannula fitting 1b to anchor portion 1a, but allows fluid agent to enter flow port 12 and flow through fluid path 16 to the needle / cannula (shown in FIG. 1) when the fluid agent is in the pump chamber.

[0044] In the exemplary intermediate pumping chamber 200, the passive check valve 2 may be configured to prevent backflow of liquid agent when the pump chamber is filled with liquid agent (shown in later examples / figures) from a tank (shown in FIG. 1).

[0045] The plunger 3 may be configured to form a leak-proof seal against the side of the chamber body 10. The plunger 3 shown in the examples below is operable to draw the liquid agent from the reservoir and expel the liquid agent through the fluid path 16 into a needle or cannula (not shown in this example). The surface of the plunger 3 facing the rear 200b of the intermediate pump chamber 200 may be coupled to or abut against a plunger spring 4. The plunger spring 4 may be, for example, a compression spring shown in a resting state in FIG. 2. The end of the plunger spring 4 opposite the plunger 3 may be coupled to or rest against a hard stop 7.

[0046] In this example, the plunger 3 is configured with a plunger channel 3a and a plunger bend snap 9. The plunger channel 3a may be a hollow central portion into which the anchor portion 1a of the sliding fluid member 1 fits. The plunger channel 3a may be configured to surround the anchor portion 1a of the sliding fluid member 1. The interface between the plunger channel 3a and the anchor portion 1a is leak-proof, but the anchor portion 1a is configured to slide back and forth through the plunger channel 3a. The plunger bend snap 9 may be flexible and extend along the surface of the anchor portion 1a of the sliding fluid member 1, terminating in a bulbous portion (or, in another embodiment, a concave surface, or a portion complementary to the hard stop bend snap 8).

[0047] A face seal 11 may be disposed between the anchor portion 1a of the sliding fluid member 1 and the needle / cannula fitting 1b and around the flow port 12. The face seal 11 may be operable to provide a leak-proof seal of the flow port 12 that limits leakage of the liquid agent through or around the flow port 12 and into the fluid pathway 16 to the needle or cannula. The face seal 11 may be configured to prevent flow of the liquid agent to the patient while the intermediate pumping chamber is in the initial position. During some stages of operation, the face seal 11 may be under pressure, for example, from the plunger spring 4 of the intermediate pumping chamber 200 that prevents the liquid agent from entering the fluid pathway 16.

[0048] The SMA wire 6 may be a Nitinol or other known shape memory alloy wire operable to change length or shape in response to the application of an electric current. For example, the SMA wire 6 may be coupled to a power source via circuitry configured to apply a current or voltage to actuate the SMA wire 6 when actuated in response to a control signal from a controller (such as shown in FIG. 1).

[0049] The hard stop 7 may be configured to limit the movement of the plunger 3. The hard stop 7 may be configured to include two hard stop flexures 8a configured to extend from the hard stop 7 toward the front 200a of the intermediate pump chamber 200. In the exemplary intermediate pumping chamber 200, each of the two hard stop flexures 8a may include a hard stop flexure snap 8 at the end of the hard stop flexure 8a closest to the plunger 3. The hard stop flexure snaps 8 are, in this example, two flexible arm-like structures having an inward recess (or, in another embodiment, a protrusion, or a portion complementary to the plunger flexure snap 9) at each end of the flexible arm-like structure. Although two hard stop flexure snaps 8 are shown, the number of hard stop flexure snaps 8 may be approximately 1, 3, or 4, etc., and in other examples may be utilized to engage more or less of the plunger flexure snaps 9 of the plunger 3. The interaction of the hard stop flexure snaps 8 and the plunger flexure snaps 9 will be described in more detail in the examples below.

[0050] FIG. 3A shows a cross-sectional side view of the intermediate pumping chamber during transition from an initial position to the filling stage.

[0051] 3A shows the operation of the intermediate pumping chamber 200 in response to filling with liquid agent 20 from a tank via tank fitting 201. The SMA wire 6 is coupled to anchor portion 1a and to circuitry (not shown in this example) that responds to signals from a controller (shown in the previous example).

[0052] In response to actuation, the SMA wire 6 may pull on the anchor portion 1a of the sliding fluid member 1 which pulls the plunger 3 in the direction shown by arrow A. Pulling the SMA wire 6 in the direction of arrow A pulls the sliding fluid member 1 and plunger 3 away from the front face 205 of the intermediate pumping chamber 200 and away from the passive check valve 2. The pulling action of the SMA wire 6 on the anchor portion 1a creates a vacuum in the pump chamber 22. The vacuum causes the passive check valve 2 to open in the same direction that the sliding fluid member 1 and plunger 3 are moving (as shown by the unsigned arrow on the passive check valve 2), allowing the pump chamber 22 to begin filling with the liquid agent 20 from the tank via the tank fitting 201.

[0053] During this filling stage, compression of the fluid member spring 5 increases the force (against the first plunger surface 3c of the plunger 3) pressing the face seal 11 against the flow port 12 (e.g., F=-kx, where F is force, k is the spring constant, and x is the distance the spring is compressed from its rest position). The position of the hard stop 7 opposite the front surface 205 of the intermediate pumping chamber 200 may be varied under closely controlled conditions to allow adjustment of the pump stroke, or alternatively, the position of the hard stop 7 may be factory configured for a pre-set pump stroke. The length of the SMA wire 6 may be configured based on adjusting or setting the pump stroke of the plunger and the position of the hard stop 7 to achieve the correct amount of pump stroke.

[0054] In the example of FIG. 3A, the plunger 3 and the sliding fluid member 1 are translating backwards towards the rear 200b of the intermediate pumping chamber 200. As the plunger 3 and the sliding fluid member 1 are translating backwards, the hard stop flexures 8a will interact. The plunger flexure snaps 9 are configured with semicircular protrusions that, upon contact with the hard stop flexures 8a, open the hard stop flexures 8a on both sides of the hard stop 7 towards the respective sides of the chamber body 10. When the hard stop flexures 8a separate, the semicircular protrusions on the plunger flexure snaps 9 fill the hard stop flexure snaps 8, which are recesses in the hard stop flexures 8a of the hard stop 7. This creates a bidirectional latch / snap that prevents the sliding fluid member 1 and the plunger 3 from translating further backwards towards the rear 200b of the intermediate pumping chamber 200.

[0055] FIG. 3B shows an example of the effective flow area of ​​the pump chamber in the example of FIG. 3A. As shown in the example of FIG. 3B, the effective flow area 33 may be annular. The annular effective flow area 33 allows for the use of larger parts such as the plunger 3, the slidable fluid member 1, and the intermediate pumping chamber 10, which is advantageous for the manufacture and assembly of the components. For example, the annular effective flow 33 may be the result of using a cylindrical structure (such as the cylindrical plunger and cylindrical chamber body 10 (shown in the previous example)), which is easier to manufacture and assemble. Of course, other shapes such as oval, rectangular, square, etc. may be used. For example, the ratio between d1 and d2 may be set so that dimensional control of the effective flow area 33 section can be achieved. This dimensional control facilitates scaling up the pump chamber size and plunger size so that manufacturing tolerances can be a small or even smaller percentage of the actual size of the device 105. By controlling such dimensions d1 and d2, a desired pump chamber volume may be achieved. For a small pump volume, the larger the chamber and plunger, the closer the chamber and plunger will be to their nominal dimensions. The approximate area of ​​the effective flow path area 33 may be determined using the following formula: [(d2 / 2)2×π]-[(d1 / 2)2×π]-(area of ​​the flow ports 12 extending beyond d1), where d2 is the diameter of the plunger 3 and d1 is the diameter of the sliding fluid member 1.

[0056] In FIG. 4, the intermediate pumping chamber 200 has reached a full stroke, the pump chamber 22 is filled with the liquid agent 20, and the passive check valve 22 is closed as the pressure returns to essentially about 0 pounds per square inch gauge (psig). The plunger spring 4 and the FM spring 5 are both compressed and store energy. In this example, the plunger flexure snap 9 is operable to achieve several movements, such as limiting the movement of the plunger 3 in the intermediate pumping chamber 200 as it draws the liquid agent 20 from the tank (i.e., 126 in FIG. 1) into the pump chamber 22, the SMA wire 6 helps maintain the stored energy of the plunger spring 4 and the FM spring 5, and prevents the plunger 3 from moving back toward the front surface 205 until the sliding fluid member 1 reaches a certain point in its stroke. As will be further described with reference to another figure, the plunger flexure snap 9 and the hard stop flexure snap 8 may provide an electrical interface (e.g., electrical contacts on their respective surfaces, etc.) operable to verify that the pump chamber 22 is full or that the delivery of the liquid agent has commenced when coupled to a control circuit. The position shown in FIG. 4 is sometimes referred to as the full or loaded position.

[0057] 5, in response to the current being released from the SMA wire 6, the SMA wire 6 is de-energized and begins to return to its pre-actuation state. Furthermore, the FM spring 5 pushes the sliding fluid member 1 back (as indicated by arrow B) towards the initial position shown in FIG. 2. Depending on the configuration of the SMA wire 6 and the FM spring 5, the SMA wire 6 may act as a brake for the FM spring 5 (and limit the force applied by the FM spring 5) to slow the movement of the sliding fluid member 1 in the direction of arrow B. Alternatively, the SMA wire 6 may be configured to allow the FM spring 5 to exert its full force on the sliding fluid member 1.

[0058] As the sliding fluid member 1 moves towards the front face 205, the face seal 11 is no longer intact against the front face of the plunger 3, thereby exposing the flow ports 12. In this example, the sliding fluid member 1 is able to move within the space of the pump chamber 22 without moving much, if any, liquid into the fluid path 16.

[0059] Furthermore, when the sliding fluid member 1 moves towards the front surface 205, the plunger 3 remains stationary as the plunger flex snap 9 and the hard stop flex snap 8 remain connected by the support provided by the sliding fluid member 1.

[0060] In the example, the anchor portion 1a of the sliding fluid member 1 supports the plunger flex snap 9 when fully retracted into the plunger 3 (as shown in FIG. 3A ). The support provided to the plunger flex snap 9 by the sliding fluid member 1 serves to keep the plunger flex snap 9 coupled to the hardstop flex snap 8.

[0061] However, when the sliding fluid member 1 moves in the direction of the arrow B in FIG. 5, the connection between the plunger flexure snap 9 and the hard stop flexure snap 8 becomes unstable.

[0062] FIG. 6 shows the SMA wire 6 relaxing and the sliding fluid member 1 reaching the forward limit of its travel by impacting against the inside of the front of the intermediate pumping chamber 200 in response to the force of the FM spring 5 against the anchor portion 1a.

[0063] Due to the lack of support for the plunger flexure 9a by the anchor portion 1a, the plunger flexure 9a may be more prone to bending. Due to the lack of support, the hardstop flexure 8a does not have to bend as much to release the coupling between the respective plunger flexure snap 9 and hardstop flexure snap 8. The movement of the respective hardstop flexure snap 8 and plunger flexure snap 9 is shown by arrows E and F. As shown in FIG. 6, the force applied to the plunger 3 by the plunger spring 4 causes the plunger 3 to move in the direction shown by arrow C, creating instability in the coupling between the respective plunger flexure snap 9 and hardstop flexure snap 8. This instability allows the force of the plunger spring 4 to overcome the frictional forces that maintain the coupling between the plunger flexure snap 9 and hardstop flexure snap 8, causing the respective plunger flexure 9a and hardstop flexure 8a to bend, thereby releasing the plunger 3 and continuing to move toward the front of the intermediate pumping chamber 200.

[0064] In an additional example, uncoupling the plunger flex snap 9 and hardstop flex snap 8 also severs the electrical connection formed by the coupled plunger flex snap 9 and hardstop flex snap 8. The controller may interpret this as dispensing the fluid path 16 and the liquid medication to the user.

[0065] Figure 7 shows the movement of the plunger expelling the liquid from the pump chamber 22. In the example of Figure 7, the plunger 3 is shown collapsing the pump chamber 22 under the force of the plunger spring 4, forcing the liquid 20 in the pump chamber 22 out of the outlet orifice 12. The passive check valve 2 closes under the pressure of the liquid 20, preventing any of the liquid 20 from returning to the tank. The pump flow rate Q is a factor of the spring constant, the flow port diameter / length and the pipe dimensions to the patient, and is best described by Poiseuille's law as follows:

[0066]

number

[0067] Once the pump chamber 22 is fully collapsed by the force of the plunger spring 4, the intermediate pump chamber 200 returns to its initial position as shown in Figure 2. In this state, the intermediate pumping chamber 200 is at rest and ready to be re-energized for another pulse to expel the liquid medication to the user.

[0068] In contrast to the embodiment shown in Figures 2-7, the plunger flexure snap 9 and hard stop flexure 8a and hard stop flexure snap 8 may be optional if other means of limiting the movement of the plunger 3 are available. For example, in Figure 8, the intermediate pumping chamber may hydraulically limit itself. Furthermore, in some configurations or applications (e.g., pumping applications lasting longer than the use cycle of the drug ejection device for insulin), the use of flexure snaps may induce increased friction losses, which may not be tolerable for long-term use (e.g., for periods of more than one week).

[0069] FIG. 8 shows a side cross-sectional view of another example of an intermediate pumping chamber of a wearable drug ejection system. The intermediate pumping chamber 800 may have a front portion 800a and a rear portion 800b, and may be coupled to a tank containing a liquid drug via a tank coupling 801. The intermediate pumping chamber 800 may be operable to change its configuration during operation. For example, the initial position of FIG. 8 may be a position where no liquid drug is being drawn from the tank into the pump chamber (as shown in more detail in a later figure). The main components of the exemplary intermediate pumping chamber 200 may include a sliding fluid member 815, a chamber body 880, and a plunger 820. Additional components may include a passive check valve 810, a plunger spring 830, a fluid member (FM) spring 840, a shape memory alloy (SMA) wire 850, a hard stop 870, and a face seal 811. The plunger spring 830 and the FM spring 840 may be, for example, compression springs, and are shown in their respective rest positions when the intermediate pumping chamber 800 is in this initial position. The initial position of the plunger 820 and the sliding fluid member 815 shown in the example of Figure 8 is also referred to as the rest position of the front 800a of the intermediate pumping chamber 800. Of course, other types of springs or other types of devices may be used in place of the springs in the exemplary intermediate pumping chamber 800.

[0070] The sliding fluid member 815 may be configured with an anchor portion 815a, a needle / cannula fitting 815b, and a flow port 812. The sliding fluid member 815 may include a flow port 812 incorporated into the sliding fluid member 815. The sliding fluid member 1 may be coupled to a needle or cannula, such as 129 in FIG. 1. The anchor portion 815a may include structure (not shown in this example for ease of illustration) that connects to the needle / cannula fitting 815b. Such structure is configured to provide a fluid passage in the flow port 812 that allows the liquid agent to enter the flow port and flow through the fluid path 816 to the needle / cannula.

[0071] In the exemplary intermediate pumping chamber 800, a passive check valve 810 may be configured to prevent backflow of liquid agent when the pump chamber is filled with liquid agent (shown in an example below) from a tank (shown in FIG. 1).

[0072] The plunger 820 may be configured to form a leak-proof seal against the side of the chamber body 880. The plunger 820 shown in the examples below is operable to draw the liquid drug from the reservoir and expel it through the fluid path 816 into a needle or cannula (not shown in this example). The surface of the plunger 820 facing the rear 800b of the intermediate pumping chamber 800 may be coupled to or abut a plunger spring 830. The end of the plunger spring 830 opposite the plunger 820 may be coupled to or rest against a hard stop 870.

[0073] In this example, the plunger 820 is configured with a plunger channel 820a and a plunger hard stop 860. The plunger channel 820a may be a hollow central portion that fits into the anchor portion 815a of the sliding fluid member 815. The plunger channel 820a may be configured to surround the anchor portion 815a of the sliding fluid member 815. The interface between the plunger channel 3a and the anchor portion 1a is leak-tight, but the anchor portion 1a is configured to slide back and forth through the plunger channel 820a.

[0074] A face seal 811 may be disposed between the plunger 820 and the needle / cannula fitting 815b of the sliding fluid member 815 to provide a leak-proof seal. The face seal 811 may be formed as a compression seal between the sliding fluid member 815 and a surface of the plunger 820. Alternatively or additionally, the face seal 811 may be an elastomeric seal coupled to the sliding fluid member 815 (or the plunger 820). The face seal 811 may be configured to limit leakage of the liquid agent through or around the flow port 812 into the fluid path 16 to the needle or cannula. The face seal 811 may be further configured to prevent flow of the liquid agent to the patient while the intermediate pumping chamber is in the initial position. During some stages of operation, the face seal 811 may receive pressure, for example, from the plunger spring 830 of the intermediate pumping chamber 800, to prevent any liquid agent from entering the fluid path 816.

[0075] SMA wire 850 may be Nitinol or other known shape memory alloy wire operable to change length or shape in response to application of electrical current. For example, SMA wire 850 may be coupled to a power source via circuitry configured to apply a current or voltage to actuate SMA wire 850 upon actuation in response to a control signal from a controller (such as shown in FIG. 1). Hard stop 870 may be configured to limit movement of plunger 830 when hard stop 870 contacts plunger hard stop 860.

[0076] Figure 9 shows a side cross-sectional view of an intermediate pumping chamber of a discharge pump apparatus in transition from an initial state of a pumping cycle of the intermediate pumping chamber shown in the example of Figure 8. In the example of Figure 9, the SMA wire 850 may be energized (or actuated) by a controller. In response to energization or actuation, the SMA wire 850 may begin to pull the anchor portion 815a of the sliding fluid member 815 toward the rear 800b of the intermediate pumping chamber 800 (toward the rear 800b in the direction shown by arrow G).

[0077] As anchor portion 815a is pulled towards rear portion 800b, plunger spring 830 and FM spring 840 are compressed from their rest positions, and a vacuum is created, drawing liquid agent 825 from the tank through tank fitting 801 and into pump chamber 822. Face seal 811 maintains pressure on plunger 820 as anchor portion 815a is pulled towards rear portion 800b by SMA wire 850, thereby preventing liquid agent from entering flow port 812.

[0078] Figure 10 shows a side cross-sectional view of the intermediate pumping chamber in the example of Figure 9 in a filled state prior to expelling liquid agent from the pump chamber. In the example of Figure 10, a controller (not shown in this example) no longer applies current to SMA wire 850.

[0079] When the current is removed from the SMA wire 850, the force provided by the FM spring 840 may begin to induce a reversal movement of the anchor portion 815a of the sliding fluid member 815. Due to the larger surface area of ​​the plunger relative to the portion of the surface area of ​​the sliding fluid member opposite the face seal 811, the anchor portion 815a may begin to move within the plunger 820 through the plunger channel 820a while the plunger 820 is momentarily hydraulically stopped in place against the hard stop 860 (by the incompressible volume of fluid 825).

[0080] 10, SMA wire 850 may be energized by the controller until a current spike is detected by the controller, for example, when plunger hard stop 860 hits the wall formed by hard stop 870. In this example, the timing of the release of plunger 820 may be coordinated with hydraulic damping due to fluid 825 in filled pump chamber 822 and the pull applied by energized SMA wire 850 to anchor portion 815a.

[0081] Because the sliding fluid member 815 does not displace any fluid during its movement towards the front portion 800a, there may be no additional force preventing the sliding fluid member 815 from reaching a "park position" before the plunger 820 begins to move towards the front portion 800a. As the plunger 820 moves, the entire liquid agent 825 may be expelled from the pumping chamber 822.

[0082] FIG. 11 illustrates a cross-sectional view of an exemplary intermediate pumping chamber transitioning from a filling state to a discharging state in the example of FIG.

[0083] Based on the spring constant of the FM spring 840, the surface area of ​​the plunger in contact with the fluid, the viscosity of the fluid and the parameters of the flow port 12, the parameters of the fluid path 816, etc., in the example of FIG. 11, the plunger 820 may start moving toward the stop position of the front portion 800a before the sliding fluid member 815 reaches the stop position of the front portion 800a of the intermediate pumping chamber 800. In FIG. 11, the sliding fluid member 815 is shown in the stop position of the front portion 800a of the intermediate pumping chamber 800. The plunger spring 830 exerts a force on the plunger 820 to move the plunger 820 toward the front portion 800a. When the plunger 820 moves and the flow port 812 is no longer sealed by the face seal 811, the movement of the plunger 820 toward the front portion 800a of the intermediate pumping chamber 800 causes the liquid agent 825 to be expelled from the pump chamber 822.

[0084] When the plunger spring 4 returns to its initial or rest position as shown in FIG. 8, the intermediate pumping chamber 800 is ready and ready to wait for another pulse.

[0085] FIG. 12 illustrates an exemplary configuration of electrical contacts for various control aspects of the discharge pump device.

[0086] The exemplary configuration 1200 illustrates an example of a plunger flexure 1230 , a hardstop flexure 1240 , and a controller 1210 .

[0087] The plunger flexure 1230 may include a plunger flexure snap 1233. The plunger flexure snap 1233 may be a protrusion disposed at the end of the plunger flexure 1230 as shown in the previously listed embodiments of Figures 2-7. The plunger flexure snap 1233 may include plunger flexure snap (PFS) contacts 1237a and 1237b coupled together by the wire 121.

[0088] The hard stop flexure 1240 may include a hard stop snap 1243. Hard stop snap (HSS) contacts 1247a and 1247b are disposed within the hard stop flexure snap 1243. The hard stop flexure snap 1243 may be a recess or bowl-shaped depression in the hard stop flexure 1240 as shown in the previously cited embodiments of Figures 2-7. The HSS contacts 1247a and 1247b are shown coupled via a wired connection to a controller 1210 of the drug ejection device, such as 104 in the example of Figure 1. The plunger flexure snap 1233 is configured to interact with the hard stop snap 1243. Of course, the plunger flexure snap 1233 and the hard stop snap 1243 may have other shapes that allow for coupling of the respective snaps 1233 and 1243.

[0089] The controller 1210 may be coupled to HSS contact 1247a via connector 1203 and to HSS contact 1247b by connector 1207. The controller 1210 may be operable to respond when the plunger flexure snap 1233 moves in the direction of arrow M and PSF contacts 1237a and 1237b contact HSS contacts 1247a and 1247b, respectively. Upon contact, a circuit is completed within the controller 1210. This indicates that the plunger has reached the intermediate pumping chamber hard stop (shown in the previous example). In the example 1200, electrical contacts are shown by way of example. However, other devices and mechanisms may be used to determine the status of a drug ejection device such as 105 in Fig. 1, such as additional electrical switches and interconnections, optical devices coupled to the controller and configured to indicate the position of the plunger, magnetic / eddy current detectors, capacitive fluid sensing devices coupled to various components in the pump chamber, Linear Variable Displacement Transducers (LVDTs) or other linear displacement measuring tools, pressure sensors, flow sensors on the injection tube or Bourdon tube, etc. For example, a Bourdon tube may be configured to detect pressure that causes distortion or deformation in tubing such as fluid path 16 or 816. For example, the flow sensor may be operable to respond to a check valve leak or backflow.

[0090] In another example, a controller such as 102 of Figure 1 or 1210 of Figure 12 may be configured to execute logic that causes the controller to perform different functions. Figure 13 is a flow chart of a process that may utilize the example of Figures 1-12 to expel a drug from a dispensing pump device.

[0091] In process 1300, for example, a controller may determine that it is time to output a medication from the delivery pump device. For example, the controller may be equipped with a clock or an input device that indicates to the controller that a dose of medication should be delivered to the user (1310).

[0092] In response to this determination, the controller may generate a control signal to operate the discharge pump device 1320. The controller may be operable to output the control signal to a pump mechanism operable to move the sliding fluid member, for example, as described with reference to the examples of Figures 2-11.

[0093] In this example, the controller may be operable to apply a control signal to a pump mechanism (1330). The pump mechanism may be a shape memory alloy wire (as described with reference to previous examples) or an electric motor. In some examples, the intermediate pumping chamber and associated mechanism may comprise a drive system coupled to a sliding fluid member (as shown in the examples of Figures 2-11). The drive system may be configured to be driven, for example, by a rotating cam, a linkage, a rack, or a lead screw with an escapement mechanism. In another particular example, the drive system may be tuned to allow for the use of a low-power electric motor.

[0094] As a control signal is applied to the pump mechanism, the pump chamber (as shown in the previous example) fills with liquid agent. As described with reference to the previous example, a shape memory wire is used to pull on the sliding fluid member to allow filling of the pump chamber.

[0095] The controller may be configured to determine, for example, that the control signal should be removed from the pump mechanism of the discharge pump device (1340). This determination may be performed as described with reference to the exemplary configuration shown in FIG. 12. Alternatively, the sliding fluid member may be magnetized and eddy currents may be measured and evaluated to determine the proximity of the sliding fluid member to the hard stop wall. The eddy current configuration may allow partial or multiple dosing in the same intermediate pumping chamber since the eddy currents will have different values ​​as the sliding fluid member moves. Of course, other methods or arrangements of electrical contacts may be used to determine the position of the sliding fluid member in the intermediate pumping chamber. Once the controller determines that the control signal may be removed from the pump mechanism, it may stop applying or have stopped applying, at 1350, a signal (responsive to the control signal) to a drive mechanism such as a shape memory alloy. By ceasing application of the control signal, the controller allows the spring in the intermediate pumping chamber to begin expelling the liquid agent from the pump chamber through the fluid path to the needle / cannula and into the patient. For example, ejection of the liquid medication may enable ejection of the liquid medication from a medication ejection device.

[0096] In an operational example, the ejection of the liquid agent into the needle or cannula in response to the removal of the control signal from the pump mechanism may include additional steps. For example, in response to the shape memory alloy ceasing to pull on the sliding fluid member, the fluid member spring may begin to depressurize. The plunger may remain stationary because it is hydraulically blocked by the liquid agent in the pump chamber, and the fluid member spring may be depressurized to move the sliding fluid member forward of the chamber body. The liquid agent is incompressible and opposes the force exerted by the plunger spring until such time as the sliding fluid member reaches a rest or initial position, as shown in the example of FIG. 2. In this example, a flow port is available to allow the liquid agent to flow into the needle joint once the sliding fluid member reaches the initial position. Once the sliding fluid member is in the initial or rest position, the plunger spring begins to depressurize and the liquid agent is expelled from the pump chamber into the needle joint.

[0097] The controller may be operable to verify that the liquid agent has been dispensed or expelled from the pump chamber, or that dispensing or expulsion has been initiated, at 1360. For example, the sliding fluid member may comprise electrical contacts, such as the eddy current example discussed above.

[0098] The entire system can be moved by sealing the back of the plunger / sliding fluid member and drawing a vacuum using a small air pump. With this system, it will be possible to measure the pressure in the vacuum chamber. Furthermore, the position of the plunger can be established through calculations using Boyle's law (P1V1=P2V2).

[0099] This system may be modified to utilize a phase change wax instead of a shape memory alloy for the plunger movement as described in U.S. Patent No. 10,391,237, the disclosure of which is incorporated herein by reference in its entirety.

[0100] Software-related implementations of the techniques described herein may include, but are not limited to, firmware, application-specific software, or any other type of computer-readable instructions that may be executed by one or more processors. Hardware-related implementations of the techniques described herein may include, but are not limited to, integrated circuits (ICs), application-specific ICs (ASICs), field programmable arrays (FPGAs), and / or programmable logic devices (PLDs). In some examples, the techniques described herein and / or any systems or components described herein may be implemented by a processor executing computer-readable instructions stored in one or more memory components.

[0101] Additionally or alternatively, although the examples are described with reference to implementing a closed-loop algorithm, variations of the disclosed examples may be implemented to allow for open-loop use. An open-loop implementation allows for the use of various insulin delivery modalities such as smart pens, syringes, etc. For example, the disclosed AP application and algorithms may be operable to perform various functions associated with open-loop operation, such as generating prompts requesting input of information such as weight or age. Similarly, a dose of insulin may be received from a user by the AP application or algorithm via a user interface. Other open-loop operations may also be implemented by adjusting user settings of the AP application or algorithm, etc.

[0102] Some examples of the disclosed apparatus may be implemented using, for example, a storage medium, computer readable medium, or article of manufacture that may store instructions or a set of instructions. The instructions or set of instructions, when executed by a machine (i.e., a processor or microcontroller), may cause the machine to perform methods and / or operations according to examples of the disclosure. Such machines may comprise, for example, any suitable processing platform, computing platform, computing device, processing device, computing system, processing system, computer, processor, etc., and may be implemented using any suitable combination of hardware and / or software. A computer readable medium or article may include, for example, any suitable type of memory unit, memory, memory article, memory medium, storage device, storage article, storage medium and / or storage unit, such as memory (including non-transitory memory), removable or non-removable media, erasable or non-erasable media, writable or rewritable media, digital or analog media, hard disk, floppy disk, compact disk read only memory (CD-ROM), recordable compact disk (CD-R), rewriteable compact disk (CD-RW), optical disk, magnetic media, magneto-optical media, removable memory cards or disks, various digital versatile disks (DVDs), tapes, cassettes, etc. The instructions may include any suitable type of code, such as source code, compiled code, interpreted code, executable code, static code, dynamic code, encrypted code, programming code implemented using any suitable high-level programming language, low-level programming language, object-oriented programming language, visual programming language, compiled programming language and / or interpreted programming language. The programming code embodied in the non-transitory computer readable medium may cause a processor, when executing the programming code, to perform functions as described herein.

[0103] Specific examples of the present disclosure have been described above. However, it is expressly noted that the present disclosure is not limited to such examples, but rather additions and modifications to those explicitly described herein are also intended to be included within the scope of the disclosed examples. Furthermore, it is to be understood that the features of the various examples described herein are not mutually exclusive and may exist in various combinations and permutations without departing from the spirit and scope of the disclosed examples, even if such combinations or permutations are not expressly stated herein. Indeed, those skilled in the art will recognize variations, modifications, and other implementations of the contents described herein without departing from the spirit and scope of the disclosed examples. Thus, the disclosed examples should not be limited solely by the illustrative description set forth above.

[0104] The program aspects of this technology may be considered as a "product" or "article" in the form of executable code and / or associated data typically carried on or embedded in some type of non-transitory machine-readable medium. Storage-type media includes all or part of the tangible memory of a computer, processor, etc., or associated modules such as various semiconductor memories, tape drives, disk drives, etc., that may provide non-transitory storage for software programming at any time. Note that the Abstract of the Disclosure is provided to enable the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. Moreover, the foregoing Detailed Description has grouped various features together in a single example to simplify the disclosure. This method of disclosure should not be interpreted as reflecting an intention that the claimed example requires more features than are expressly recited in each claim. Rather, as the following claims reflect, not all features of a single disclosed example are the subject matter of the present invention. For this reason, the following claims are incorporated into the Detailed Description herein, with each claim standing on its own as a separate example. In the appended claims, the terms "including" and "in which" are used as the plain English equivalents of the respective terms "comprising" and "wherein." Moreover, the terms "first," "second," "third," etc. are used merely as labels and are not intended to impose numerical requirements on their respective objects.

[0105] The foregoing description of examples has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure to the precise form disclosed. Many modifications and variations are possible in light of this disclosure. It is intended that the scope of the disclosure be limited not by this detailed description, but by the appended claims. Future applications claiming priority to this application may claim the disclosed subject matter in a different manner, and may generally include any set of one or more limitations as variously disclosed or expressly set forth herein.

Claims

1. A wearable medicine ejection device, comprising: a tank configured to store a liquid agent; a pump device coupled to the tank for receiving the liquid from the tank; The discharge pump device is a chamber body forming a pump chamber; an inlet port configured to allow the liquid agent to be drawn from the reservoir into the pump chamber; a sliding fluid member including a flow port and a fluid path to the needle; a plunger configured to engage the sliding fluid member and including a plunger channel; a shape memory alloy wire coupled to the sliding fluid member; the shape memory alloy wire is operable to draw the liquid agent from the reservoir, through the inlet port, and into the pump chamber by pulling the sliding fluid member and the plunger in a first direction; A wearable drug ejection device, wherein the sliding fluid member is configured to allow the liquid drug to be drawn into the pump chamber and delivered into a fluid path from the pump chamber to an output needle.

2. 2. The wearable drug ejection device of claim 1, wherein the sliding fluid member further comprises a face seal configured to maintain a fluid-tight seal against a first plunger surface of the plunger when the shape memory alloy wire pulls the sliding fluid member.

3. The sliding fluid member is an anchor portion coupled to the shape memory alloy wire, the anchor portion configured to engage the plunger by moving within a plunger channel of the plunger in response to the pulling by the shape memory alloy wire; The wearable medication ejection device of claim 1 , further comprising: a needle joint connected to the anchor portion.

4. The wearable medication ejection device of claim 1 , wherein the plunger is configured to be in direct physical contact with an inner surface of the chamber body to form the pump chamber.

5. A fluid member spring having a first end coupled to the sliding fluid member; a plunger spring having a first end coupled to the plunger, The wearable drug ejection device of claim 1 , wherein the fluid member spring and the plunger spring are configured to be pulled from a rest position to a compressed position by the shape memory alloy wire.

6. a hard stop opposite the inlet port; a fluid member spring having a first end coupled to the sliding fluid member; a plunger spring having a first end coupled to the plunger, The wearable drug ejection device of claim 1, wherein the hard stop is configured to contact a second end of the plunger spring opposite the first end of the plunger spring and to contact a second end of the fluid member spring opposite the first end of the fluid member spring coupled to the sliding fluid member.

7. the hard stop further comprises a hard stop flex snap; the plunger further comprises a plunger bend snap; The wearable medication ejection device of claim 6 , wherein the plunger flexure snap and the hardstop flexure snap are configured to engage with each other when the shape memory alloy wire pulls on the sliding fluid member.

8. The wearable drug ejection device of claim 1 , wherein the inlet port further comprises a passive check valve.

9. a power source coupled to the shape memory alloy wire; The wearable medicine ejection device according to claim 1 , wherein the power from the power source is applied to the shape memory alloy wire to contract the shape memory alloy wire, thereby pulling the sliding fluid member.

10. a controller communicatively coupled to the power source; 10. The wearable medication ejection device of claim 9, wherein the controller is operable to activate the power source to apply power to the shape memory alloy wire according to an automatic insulin ejection application setting.

11. An ejection pump device of a wearable medicine ejection device, a chamber body forming a pump chamber, the chamber body having a hard stop and an inlet valve operable to receive the liquid agent from the tank; a plunger movable within the pump chamber of the chamber body and defining a plunger channel; a sliding fluid member movable within the pump chamber, the sliding fluid member having a needle coupling, a flow port, a face seal, and an anchor portion, the anchor portion being positioned and movable within the plunger channel in a leak-proof configuration; a shape memory alloy wire coupled to the anchor portion, the shape memory alloy wire operable to pull the anchor portion and the plunger toward the hard stop.

12. The discharge pump apparatus of claim 11 , wherein the face seal is configured to maintain a leak-tight seal against a first surface of the plunger to form the leak-tight arrangement.

13. the plunger further comprising a plunger hard stop configured to engage the hard stop of the chamber body; and a plunger spring; 12. The discharge pump apparatus of claim 11, wherein the plunger spring is in a compressed position when the plunger hard stop engages the hard stop of the chamber body.

14. The shape memory alloy wire is in response to application of an electric current to the shape memory alloy wire, pulling the sliding fluid member and the plunger in a first direction away from a front portion of the chamber body to draw the liquid agent from the reservoir, through the inlet valve and into the pump chamber; The discharge pump device according to claim 11, wherein the pulling of the sliding fluid member and the plunger is stopped and the liquid agent is filled into the pump chamber in response to the current no longer being applied to the shape memory alloy wire.

15. A plunger spring, a fluid member spring; the plunger spring is configured to contact the hard stop of the chamber body; the fluid member spring is configured to contact the hard stop of the chamber body; 15. The discharge pump apparatus of claim 14, wherein when the shape memory alloy wire stops pulling on the sliding fluid member, the plunger spring and the fluid member spring are compressed.

16. The discharge pump apparatus of claim 15, further configured such that, in response to the shape memory alloy wire stopping pulling the sliding fluid member, the fluid member spring begins to reduce pressure and the sliding fluid member moves toward the front of the chamber body, while the plunger remains stationary by being hydraulically blocked by the liquid in the pump chamber.

17. When the sliding fluid member reaches the initial position, the flow port becomes available and the liquid agent can flow into the needle coupling; 17. The dispensing pump apparatus of claim 16, further configured such that the plunger spring initiates a reduced pressure to expel the liquid agent from the pump chamber into the needle coupling.

18. a first fluid path component connecting the tank with an inlet port; a second fluid path component connecting the outlet port with the cannula; The discharge pump apparatus of claim 11 , wherein the inlet valve is positioned within the inlet port and the outlet valve is positioned within the outlet port.

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