Drive mechanism of positive displacement pumps

Abstract

A novel embodiment drive mechanism for use in pumps of the type used in wearable drug delivery systems, for example, comprises a cylindrical slider element configured with a channel defining one or more zigzag-shaped tracks on its periphery. One or more pegs are engaged within the tracks such that longitudinal movement of the slider element back and forth along the radial axis of the cylinder causes movement of the peg along one of several tracks through the channel, providing movement of the peg around the circumference of the cylinder, imparting rotational motion to a header element disposed coaxially with the slider. The header element is connected to a gear train, e.g., a planetary gear box, which is coupled to the pump via a linkage or other type of mechanism.

Description

Technical Field

[0001] Cross - reference to Related Applications This application claims the benefit of U.S. Provisional Patent Application No. 63 / 256,714, filed on October 18, 2021, the content of which is hereby incorporated by reference in its entirety.

Background Art

[0002] Many conventional automatic drug delivery systems are well - known, which include a wearable drug delivery device of the type shown in FIG. 15, for example. The drug delivery device 1500 can be designed to deliver any type of liquid drug to a user. In certain embodiments, the drug delivery device 1500 can be, for example, an OmniPod® drug delivery device manufactured by Insulet Corporation of Acton, Massachusetts. The drug delivery device 1500 can be a drug delivery device described in Patent Document 1 (U.S. Patent No. 7,303,549), Patent Document 2 (U.S. Patent No. 7,137,964), or Patent Document 3 (U.S. Patent No. 6,740,059), etc., each of which is hereby incorporated by reference in its entirety.

[0003] The drug delivery device 1500 typically includes a positive - displacement pump mechanism. Typically, the pump mechanism includes a reservoir for storing the liquid drug. The liquid drug stored in the reservoir can be delivered to the user by discharging the drug from the reservoir using a drive plunger that moves longitudinally through the reservoir to push the liquid drug through a fluid port defined within the reservoir. The plunger can be moved longitudinally through the reservoir via, for example, a lead screw or other type of linkage mechanism driven by a drive mechanism.

[0004] In wearable in-body devices, it is desirable to keep the pump mechanism and the entire drug delivery device 1500 as small as possible to minimize impact on the wearer. In addition, since such drug delivery devices are typically powered by onboard batteries, it is desirable to minimize the power required to operate the device.

[0005] In conventional drug delivery devices, the angular motion / torque required to drive the pump is provided by a ratchet mechanism. The ratchet mechanism can have, for example, two wires made of shape memory alloy (SMA), or a spring and one shape memory alloy wire such as a nitinol, metal hook, and ratchet wheel, where the shape memory alloy wire pushes the ratchet teeth, pulling the metal hook which advances the pump and delivers a single dose of liquid drug. This type of ratchet mechanism occupies a relatively large volume inside one or more housings of the drug delivery device 1500 and may require a relatively large shape memory alloy wire force to operate the pump mechanism. Therefore, using an alternative drive mechanism with a smaller shape factor plays a crucial role in reducing the overall dimensions of the drug delivery device. Furthermore, a smaller required shape memory alloy wire actuation force will reduce the total energy required to operate the device. This reduction in energy requirements will allow for the use of fewer batteries or different types of batteries with smaller shape factors to operate the device, leading to further reductions in the dimensions of the drug delivery device.

[0006] Therefore, it is desirable to replace the conventional pump mechanism with a positive displacement pump mechanism that has an improved drive mechanism for driving the plunger in the reservoir, which does not require the large implementation area of ​​the conventional pump mechanism and minimizes the power consumption of the device.

[0007] definition As used herein, the term “liquid drug” should be interpreted to include any drug in liquid form that can be administered by a drug delivery device via a subcutaneous cannula, for example, containing two or more insulins or co-formulations among GLP-1, Pramlintide, and insulin. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] U.S. Patent No. 7,303,549 [Patent Document 2] U.S. Patent No. 7,137,964 [Patent Document 3] U.S. Patent No. 6,740,059 [Overview of the Initiative]

[0009] Embodiments of the present invention disclosed herein have a novel drive mechanism for a positive displacement pump of a type used in a wearable drug delivery device. The drive mechanism provides measured rotational motion, which can be used in conjunction with various linkage mechanism designs that connect the drive mechanism to a plunger located within a reservoir in order to provide longitudinal translation of the plunger through the reservoir.

[0010] Embodiments of the present invention utilize a cylindrical slider element configured to have a channel on its circumferential surface. The channel defines a zigzag-shaped trajectory through which it passes. In various exemplary embodiments, one or more interface elements, which may be pegs or ball bearings, are engaged with the trajectory so as to cause the longitudinal movement of the slider element along its radial axis to cause the movement of one or more interface elements along the trajectory through the channel, and thus provide the movement of the interface elements around the slider element. The movement of one or more interface elements through the channel imparts rotational motion to header elements arranged coaxially with the slider element and connected to one or more interface elements. The header elements are then connected to a gear train, such as a planetary gearbox, which may be connected to a plunger of a pump mechanism via a linkage mechanism or another type of mechanism.

[0011] In the first embodiment, a channel defined on the circumferential surface of the slider element defines a single zigzag trajectory through the channel such that the longitudinal motion of the slider element along the radial axis in a first direction from a neutral position to a first position, and then the motion back to the neutral position, moves the interface element through the channel by a first angular interval, thereby rotating the header element by the first angular interval.

[0012] In the second embodiment, a channel defined within the circumferential surface of the slider element causes movement of the interface element through the channel along a first trajectory by longitudinal motion of the cylinder along the radial axis in a first direction from a neutral position to a first position, and then motion back to the neutral position, thereby defining two zigzag-shaped trajectories through the channel such that the header element rotates by a first angular interval. Longitudinal motion of the slider element along the radial axis in a second reverse direction from the neutral position to a second position, and then motion back to the neutral position causes movement of the interface element through the channel along a second trajectory, thereby rotating the header element by a second (different) angular interval. The movement of the header element at the first and second angular intervals, made possible by the respective movements of the interface element along the first and second trajectories through the channel, provides the ability to dispense different volumes of liquid using the same motion to move the slider element. The motion of the slider element in either the first or second longitudinal direction may be provided, for example, via an actuator comprising one or more wires made of SMA connected to the slider element. The operation of the slider element and its associated components will be described in more detail below.

[0013] In the drawings, similar reference numerals generally refer to the same part across different drawings. In the following description, various embodiments of the present invention will be described with reference to the following drawings. [Brief explanation of the drawing]

[0014] [Figure 1] Figure 1 shows a functional block diagram of an exemplary system suitable for carrying out the systems and methods disclosed herein. [Figure 2] Figure 2 is an exploded view of the drive mechanism according to the first embodiment of the present invention. [Figure 3] Figure 3 is an enlarged view of the zigzag-shaped trajectory of the first embodiment of the present invention. [Figure 4] Figure 4 is a perspective view of a first embodiment of the present invention, showing a drive mechanism in an unloaded configuration with the slider element in the neutral position. [Figure 5] Figure 5 is a perspective view of a first embodiment of the present invention, showing the drive mechanism in a load configuration, where the slider element has moved from a neutral position to a first position. [Figure 6] Figure 6 is a perspective view of a first embodiment of the present invention, showing the rotational motion resulting from the output shaft generated by the forward and backward movement of the slider element. [Figure 7A] Figure 7A shows an alternative embodiment of the first embodiment of the present invention that utilizes a different type of spring mechanism. [Figure 7B] Figure 7B shows a schematic side view of a modified example of a spring mechanism having offset legs. [Figure 8] Figure 8 is a schematic diagram of an alternative embodiment of the zigzag trajectory, showing a trajectory with a non-linear inclined surface that allows for better adjustment of the load profile applied to the shape memory alloy wire and the output torque applied to the pump. This inclined surface may be used in the first or second embodiments described herein. [Figure 9] Figure 9 is a block diagram of a second example of the primary embodiment, which utilizes a ball bearing between the header element and the slider element, in contrast to the peg of the first embodiment. [Figure 10] Figure 10 shows a perspective view of a second embodiment of the present invention, in which the slider element is configured to have two tracks that allow the header to rotate at two different angular intervals during one cycle. [Figure 11] Figure 11 is a perspective view of a second embodiment, showing an interface element that moves along a first larger trajectory in response to the slider element moving back and forth between a neutral position and a first position, based on the movement of the slider element in a first longitudinal direction. [Figure 12] Figure 12 is a perspective view of a second embodiment showing an interface element that moves back and forth between a neutral position and a second position along a second smaller trajectory in response to the movement of the slider element in a second longitudinal direction. [Figure 13]FIG. 13 is a perspective view of a second embodiment of the present invention, showing a configuration for providing movement of slider elements in the first and second longitudinal directions using a shape memory alloy wire and a link mechanism. [Figure 14] FIG. 14 is an alternative embodiment of either the first or second embodiment showing the use of an internal spring to return the slider element to a neutral position. [Figure 15] FIG. 15 is an example of a wearable drug delivery device in which the pumping mechanism disclosed herein can be used.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present invention provides various systems, components, and methods for moving a liquid drug from a liquid reservoir in a drug delivery device to a patient interface such as a needle or cannula. The embodiments described herein provide one or more advantages over conventional prior art systems, components, and methods, namely, a smaller footprint and reduced energy consumption.

[0016] Various embodiments of this disclosure include systems and methods for delivering drugs to a user autonomously or in accordance with radio signals received from electronic devices, using a drug delivery device (sometimes referred to herein as a “pod”). In various embodiments, the electronic device may be a smartphone, a smartwatch, a smart necklace, a user device comprising a module attached to the drug delivery device, or any other type or kind of electronic device that can be worn or carried on the user’s body and executes an algorithm to calculate the number of drug deliveries and dosages. For example, the user device may execute an “artificial-pancreas” algorithm to calculate the number of insulin deliveries and dosages. The user device may also communicate with a sensor, such as a glucose sensor, which collects data on the user’s physical characteristics or condition, such as glucose concentration. The sensor may be located inside or on the user’s body, may be part of the drug delivery device, or may be a separate device within system 100. Alternatively, the drug delivery device may communicate with the sensor instead of, or in addition to, communication between the sensor and the user device. This communication can be direct (for example, if the sensor is integrated with or part of the drug delivery device) or remote / wireless (for example, if the sensor is located in a separate housing from the drug delivery device). In these embodiments, the sensor and / or drug delivery device includes computer hardware (e.g., a processor, memory, firmware, etc.) that executes some or all of an algorithm for calculating the number of drug deliveries and the dosage.

[0017] Figure 1 shows a functional block diagram of an exemplary system suitable for carrying out the systems and methods described herein. The automated drug delivery system 100 can implement (and / or provide functionality for) drug delivery algorithms, such as those used in artificial pancreas (AP) applications, to manage or control the automated delivery of drugs or medications to a user, such as insulin, to maintain normal blood glucose levels in the blood (for example, normal blood glucose). The drug delivery system 100 may be an automated drug delivery system having a drug delivery device 102 that can be attached, a sample sensor 108, and a user device 105.

[0018] System 100 may also have accessory devices 106, such as a smartwatch or personal assistant device, which can communicate with other components of System 100 via either wired or wireless links 191-193, in any example.

[0019] The user device 105 may be a computer device such as a smartphone, tablet, personal diabetes management (PDM) device, or dedicated diabetes treatment management device. For example, the user device 105 may have a processor 151, device memory 153, user interface 158, and communication interface 154. The user device 105 may also have analog and / or digital circuits that can be executed as the processor 151 to perform processing based on program code stored in the device memory 153, such as a user application 160, to manage the user's blood glucose levels, to control the delivery of drugs, medications, or therapeutic agents to the user, and to provide other functions such as calculations of carbohydrate compensation amounts, corrected bolus amounts, etc., as described later. The user device 105 may be used to program, adjust settings, and / or control the operation of a wearable automated drug delivery device 102 and / or sample sensor 103 and any selected smart accessory device 106.

[0020] Furthermore, the processor 151 may be configured to execute programming code stored in the device memory 153, such as a user application 160. The user application 160 may be a computer application capable of operating to deliver medication based on data received from the sample sensor 103, the cloud-based service 111 and / or the user device 105 or an optional accessory device 107. The memory 153 may also store programming code for operating a user interface 158 (e.g., a touchscreen device, a camera, etc.), a communication interface 154, etc. When the user application 160 is executed, the processor 151 may be configured to provide indicators and notifications regarding food intake, blood glucose measurement, etc. The user interface 158 is under the control of the processor 151 and may be configured to present a graphical user interface, such as enabling input of meal announcements and adjusting setting selections, as described herein.

[0021] In a specific example, when the user application 160 is an artificial pancreas (AP) application, the processor 151 is also configured to execute a diabetes treatment plan managed by the user application 160 (which may be stored in memory). In addition to the functions described above, when the user application 160 is an artificial pancreas (AP) application, it may further provide functions for determining carbohydrate compensation doses, corrected bolus doses, and basal doses according to the diabetes treatment plan. Furthermore, as an artificial pancreas (AP) application, the user application 160 provides the function of outputting signals to a wearable automated drug delivery device 102 via the communication interface 154 to deliver the determined bolus and basal doses.

[0022] The communication interface 154 has one or more transceivers operating according to one or more radio frequency protocols. In one embodiment, the transceivers may include cellular transceivers and Bluetooth® transceivers. The communication interface 154 may be configured to receive and transmit signals containing information usable by the user application 160.

[0023] The user device 105 may further include one or more output devices 155, which may be, for example, speakers or vibration transducers, to provide the user with various signals.

[0024] The wearable automated drug delivery device 102, in an exemplary system 100, may include a user interface 127, a control unit 121, a drive mechanism 125, a communication interface 126, a memory 123, a power / energy harvesting circuit 128, a device sensor 184, and a reservoir 124. The wearable automated drug delivery device 102 may be configured to perform and execute the processing required to deliver multiple doses of drug to the user without input from a user device 105 or an optional accessory device 106. As will be described in more detail, the control unit 121 may be operable to determine, for example, the amount of insulin to be delivered, IOB, remaining insulin, etc., based on input from a sample sensor 108.

[0025] Memory 123 can store programming code that can be executed by the control unit 121. The programming code can enable the control unit 121 to control the delivery of drugs from the reservoir 124 and to control multiple doses of drugs based on signals from the drug delivery algorithm (MDA) 129, or based on external devices if the MDA 129 is configured to implement external control signals.

[0026] Reservoir 124 may be configured to store drugs, medications, or therapeutic agents suitable for automated delivery, such as insulin, GLP-1, plumrintide, combinations of insulin and GLP-1 or plumrintide, morphine, blood pressure medications, chemotherapy drugs, and reproductive drugs.

[0027] The device sensor 184 has one or more pressure sensors, power sensors, etc., which are communicatively connected to the control unit 121 and provide various signals. For example, the pressure sensor may be configured to provide an index of the fluid pressure detected in the fluid trajectory between the needle or cannula inserted by the user and the reservoir 124. The pressure sensor may be connected to or integrated with a needle / cannula insertion component, etc. (which may be part of the drive mechanism 125). In one example, the control unit 121 or processor 151, etc., may be operable to determine the drug infusion rate based on the fluid pressure index. The drug infusion rate may be compared to an infusion rate threshold, and the result of this comparison may be used when determining the insulin loading amount (IOB) or total daily insulin (TDI) amount.

[0028] In one embodiment, the wearable automated drug delivery device 102 has a communication interface 126, which may be a transceiver operating according to one or more radio frequency protocols such as Bluetooth®, Wi-Fi®, near-field communication, or cellular. The control unit 121 can communicate with the user device 105 and the sample sensor 108, for example, via the communication interface 126.

[0029] The wearable automated drug delivery device 102 can be attached to the body of a patient or a user such as a diabetic patient at an attachment point, and can deliver any therapeutic agent, including any of the aforementioned drugs or medications, to or around the user's attachment point. The surface of the wearable automated drug delivery device 102 may have an adhesive to facilitate attachment to the user's skin.

[0030] The wearable automated drug delivery device 102 includes, for example, a reservoir 124 for storing the drug, a needle or cannula 120 for delivering the drug into the user's body (which may be done subcutaneously, intraperitoneally, or intravenously), and a drive mechanism 125 for transferring the drug from the reservoir 124 through the needle or cannula into the user. The drive mechanism 125 may be fluidly connected to the reservoir 124 and communicatively connected to a control unit 121. The needle or cannula 120 may further include a needle / cannula insertion mechanism (not shown) which may be integrated with or attachable to the drug delivery device 102.

[0031] The wearable automatic drug delivery device 102 may further have a power source 128, such as a battery, piezoelectric device, or energy harvesting device, to supply power to the drive mechanism 125 and / or other components of the wearable automatic drug delivery device 102 (such as the control unit 121, memory 123, and communication interface 126).

[0032] In some embodiments, the wearable automated drug delivery device 102 and / or user device 105 includes a user interface 158 and output devices 155 such as a keypad, touchscreen display, lever, light-emitting diode, buttons on the housing of the drug delivery device 102, microphone, camera, speaker, and display, configured to allow the user to input information and the user device 105 to output information (e.g., alarm signals) to present to the user. The user interface 158 can provide inputs such as voice input, gesture input to a camera (e.g., hand or face), and swiping to a touchscreen to a processor 151 interpreted by the user application 160.

[0033] When the wearable automated drug delivery device 102 is configured to communicate with an external device such as a user device 105 or a sample sensor 108, it can receive signals from the user device 105 or the sample sensor 108 via a wired or wireless link 194. The control unit 121 of the wearable automated drug delivery device 102 can receive and process signals from each external device and can deliver drugs to the user according to a diabetes treatment plan or other drug delivery plan.

[0034] In an example of operation, when the user application 160 is executed, the processor 121 can output control signals that activate the drive mechanism 125 to deliver insulin carbohydrate compensation doses, corrective boluses, corrected basal doses, etc.

[0035] The accessory device 107 may be, for example, an Apple Watch®, other wearable smart devices including eyeglasses, smart jewelry, wearable fitness devices compatible with the Global Positioning System, smart clothing, etc. Similar to the user device 105, the accessory device 107 may be configured to perform various functions, including the control of a wearable automated drug delivery device 102. For example, the accessory device 107 may have a communication interface 174, a processor 171, a user interface 178, and a memory 173. The user interface 178 may be a graphical user interface presented on the touchscreen display of the smart accessory device 107. The memory 173 can store programming code for operating different functions of the smart accessory device 107, as well as instances of the user application 160, or a simplified version of the user application 160 with reduced functionality.

[0036] The sample sensor 108 may include a control unit 131, a memory 132, a detection / measurement device 133, an optional user interface 137, a power supply / energy harvesting circuit 134, and a communication interface 135. The sample sensor 108 may be communicatively connected to the management device 105 of the wearable automated drug delivery device 102 or to the processor 151 of the control unit 121. The memory 132 may be configured to store information and programming code 136.

[0037] The sample sensor 108 may be configured to detect multiple different samples, such as glucose, lactate, ketones, uric acid, sodium, potassium, and alcohol levels, and to output the detection results, such as measured values. In exemplary embodiments, the sample sensor 108 may be configured to measure blood glucose levels at predetermined time intervals, such as every 5 minutes or every minute. The communication interface 135 of the sample sensor 108 may have a circuit that acts as a transceiver for communicating the measured blood glucose levels to a user device 105 via a wireless link 195, or for communicating with a wearable automated drug delivery device 102 via a wireless communication link 108. Although referred to herein as the sample sensor 108, the detection / measurement device 133 of the sample sensor 108 may have one or more additional detection elements, such as a glucose measuring element, a heart rate monitor, or a pressure sensor. The control unit 131 has separate dedicated logic and / or components, an application-specific integrated circuit, and a microcontroller or processor that executes software instructions, firmware, programming instructions stored in memory (such as memory 132), or any combination thereof.

[0038] Similar to the control unit 121 of the drug delivery device 102, the control unit 131 of the sample sensor 108 can be configured to perform many functions. For example, the control unit 131 may be configured by programming code 136 to manage the collection and analysis of data detected by the detection and measurement device 133.

[0039] Although the sample sensor 108 is shown separately from the wearable automated drug delivery device 102 in Figure 1, in various examples the sample sensor 108 and the wearable automated drug delivery device 102 may be integrated into the same unit. That is, in various embodiments the sample sensor 108 may be integrated with the wearable automated drug delivery device 102 as part of it, and may be contained in the same housing as the wearable automated drug delivery device 102 or in a housing that can be attached to it. In such exemplary configurations the control unit 121 can independently perform the functions required for proper drug delivery without any external input from the user device 105, cloud-based service 111, another sensor (not shown), optional accessory device 107, etc.

[0040] The communication link 115 connecting the cloud-based service 111 to each device 102, 105, 106, and 108 of the system 100 may be a cellular link, a Wi-Fi® link, a Bluetooth® link, or a combination thereof. The service provided by the cloud-based service 111 may have a data memory that stores data that can be depersonalized, such as blood glucose measurements, past IOB or TDI, prior carbohydrate compensation doses, and other forms of data. Furthermore, the cloud-based service 111 can process anonymized data from a large number of users to provide generalized information regarding TDI, insulin sensitivity, IOB, etc.

[0041] Wireless communication links 191-196 can be any type of wireless link operating using known or proprietary wireless communication standards. For example, wireless communication links 191-196 may provide communication links based on Bluetooth®, Zigbee®, Wi-Fi®, short-range communication standards, cellular standards, or any other wireless protocol via their respective communication interfaces 154, 174, 126, and 135.

[0042] User application 160 (or MDA 129) may provide periodic insulin microboluses over a predicted period (e.g., 60 minutes) based on past glucose measurements and / or predicted glucose levels. The optimal postprandial control unit may request the user to deliver meal boluses in the same manner as current pump therapy, but the normal operation of user application 160 compensates for any meal boluses that are not delivered, mitigating prolonged hyperglycemia. User application 160 employs a control-versus-target strategy that attempts to achieve and maintain set target blood glucose levels, thereby reducing the duration of prolonged hyperglycemia and hypoglycemia.

[0043] The user application 160 implements a graphical user interface, which is the first interface with the user, and is used to start and stop the wearable drug delivery device 102, to program the base and bolus computer settings for manual mode, and to program the program settings specific to automatic mode (hybrid closed-loop or closed-loop).

[0044] In manual mode, the user application 160 delivers insulin at programmed baseline rates and bolus volumes, using the option to set a provisional baseline profile. The control unit 121 also has the ability to function as a sensor expansion pump in manual mode, using sensor glucose data provided by the sample sensor 108 for input into the bolus calculator.

[0045] In automatic mode, the user application 160 assists in the use of multiple target blood glucose levels. For example, in one embodiment, the target blood glucose level may be in the range of 110 mg / dL to 150 mg / dL, in increments of 10 mg / dL, in increments of 5 mg / dL, or other increments, preferably in increments of 10 mg / dL. The user experience reflects the current setup flow, thereby assisting the healthcare provider in programming the basal rate, glucose target, and bolus calculator setup. These inform the user application 160 about insulin administration parameters. The insulin administration parameters are adapted over time based on the total daily insulin (TDI) delivered during each use of the drug delivery device 102. A pseudo-hypoglycemic protection mode can be implemented by the user during various durations in automatic mode. In hypoglycemic protection mode, the algorithm is intended to be used over pseudo-durations when insulin delivery is reduced and higher insulin sensitivity is expected (e.g., during exercise).

[0046] The user application 160 can use large characters, graphics, and on-screen instructions to prompt the user throughout the setup process and the use of the system 100. It is also used to program the user's customized basal insulin delivery profile, check the status of the drug delivery device 102, initiate insulin bolus administration, modify the patient's insulin delivery profile, handle system alerts and alarms, and allow the user to switch between automatic and manual modes.

[0047] In some embodiments, the user device 105 and the sample sensor 108 do not need to communicate directly with each other. Instead, data from the sample sensor (e.g., blood glucose level) may be transmitted to the drug delivery device 102 via link 196 and then relayed to the user device 105 via link 194. In some embodiments, the serial number of the sample sensor must be entered into the user application 160 to enable communication between the sample sensor 108 and the user device 102.

[0048] User application 160 can provide the ability to calculate a proposed bolus dose through the use of a bolus calculator. The bolus calculator is provided for the user's convenience to help determine a proposed bolus dose based on ingested carbohydrates, the most recent blood glucose measurement (or a fingertip measurement), a programmable correction factor, the insulin-to-carbohydrate ratio, the target blood glucose level, and the insulin on board (IOB). IOB is estimated by user application 160, taking into account manual boluses and insulin.

[0049] Software-related implementations of the technologies described herein may include, but are not limited to, firmware, application-specific software, or any other type of computer-readable instruction that can be executed by one or more processors. Computer-readable instructions may be provided via a non-temporary computer-readable medium. Hardware-related implementations of the technologies described herein include, but are not limited to, integrated circuits (ICs), application-specific integrated circuits (ASICs), field-programmable arrays (FPGAs), and / or programmable logic devices (PLDs). In some examples, the technologies described herein, and / or any systems or components described herein, may be executed using processors that execute computer-readable instructions stored on one or more memory components.

[0050] In a primary embodiment of the present invention, the positive displacement pump comprises a reservoir having two ends, such as an open end and a closed end. The reservoir includes a plunger located at one end, such as the open end, a drive mechanism, and a link mechanism connecting the drive mechanism to the plunger. The movement of the drive mechanism causes the plunger to move linearly toward the closed end within the reservoir, thereby releasing a liquid drug to the patient interface through a fluid port defined at the closed end of the reservoir.

[0051] A drive mechanism of a first embodiment is described herein and is shown in an exploded view in Figure 2. The device comprises a housing 202 having an integrated spring 210, although the spring 210 does not have to be physically integrated. The slider element 206 is substantially cylindrical and has a channel 216 defined on its circumferential surface. A zigzag-shaped trajectory is defined within the channel 216. The header element 204 is coaxial with the slider element 206 and has a plurality of tabs 204a extending from a body portion, these tabs 204a overlapping with the portion of the channel 216 on the slider element 206. In exemplary embodiments, the header element 204 and the slider element 206 can be manufactured using an injection molding process and may be made of, for example, polycarbonate or acetal (polyoxymethylene or POM). In other exemplary embodiments, the slider element 206 may be made of a stamped sheet metal covering its circumferential surface and defining the channel 216. To reduce friction, lubrication can be provided between the header element 204 and the slider element 206, or the header element 204 and the slider element 206 may be made of a lubricating plastic resin. Additionally or alternatively, a plurality of pegs 208 may be made rotatable along their longitudinal axes as they move or roll along the inclined surface in the channel 216. By enabling the pegs 208 to rotate as they move, the force required to push or pull the slider element 206 in either direction can be reduced. This and other features may be implemented in any of the embodiments described herein.

[0052] Multiple interface elements are positioned between the header element 204 and the slider element 206 to coordinate the movement between the header element 204 and the slider element 206. In a primary embodiment, the interface elements comprise multiple pegs 208 extending into the channel 216 through holes defined in the tab 204a of the header element 204. In an exemplary embodiment, the pegs 208 may be made of stainless steel or any other metal that provides the necessary strength, taking into account that the pegs 208 may have a relatively small diameter.

[0053] Once the slider element 206 and the header element 204 are positioned within the housing 202, the longitudinal movement of the slider element 206 along its radial axis causes the peg 208 to move in a zigzag pattern along a zigzag-shaped trajectory defined within the channel 216, thereby causing a rotation of the header element 204 around the coaxial axis of the slider element 206 and the header element 204 by a predetermined angular interval.

[0054] Figure 3 shows an enlarged view of a slider element 206 having a peg 208 positioned within a channel 216. As can be seen from the figure, when the peg 208 is positioned in the concave portion 302 of the zigzag-shaped track, the longitudinal movement of the slider element 206 in direction "A" causes the peg 208 to come into contact with the inclined portion 304 of the zigzag-shaped track, thereby forcing the header element 204 to rotate in direction "C" until the slider element 206 reaches a first position and the peg 208 comes into contact with the concave portion 306 of the zigzag-shaped track. In this regard, as the slider element 206 moves longitudinally in direction "B" when returning to the neutral position, it brings the peg 208 into contact with the inclined portion 308 of the zigzag-shaped trajectory, and further rotates the header element 204 in direction "C" until the peg 208 reaches the concave portion 310 of the zigzag-shaped trajectory when the slider element 206 reaches the neutral position. Between the neutral position and the first position, the alternating forward and backward motion of the slider element 206 in directions "A" and "B" rotates the header element 204 within the housing 202 by the movement of the peg 208 along the zigzag-shaped trajectory defined within the channel 216. Note that although Figure 3 shows only one peg, in reality, multiple pegs 208 may extend into the channel 216 from multiple tabs 204a of the header element 204. Furthermore, in this embodiment, the slider element 206 does not rotate, but the header element 204 does, while in an alternative embodiment, the slider element 206 can rotate, but the header element 204 does not.

[0055] Returning to Figure 2, the header element 204 is preferably coupled to a gear train to provide fine control over the rotation of the output shaft 228. In one embodiment of the present invention, the gear train may be a planetary gear system, as shown in Figure 2. In other embodiments, other types of gear trains can be used, such as a harmonic gear train or a set of interacting spur gears. When a planetary gear system is used, the header element 204 may define a sun gear 222 that drives the planetary gears 224 within a fixed ring gear 220. The carrier 226 is preferably directly coupled to the planetary gears 224 and may be coupled to a linkage mechanism (not shown) or other mechanism and to a plunger in a reservoir of a pump mechanism, defining an output shaft 228.

[0056] Figure 4 shows the drive mechanism 200 in its unloaded (i.e., stationary) configuration with the slider element 206 in the neutral position. In one embodiment, longitudinal motion of the slider element 206 along its radial axis in a first direction can be achieved by connecting it to a wire 212 made of shape memory alloy (SMA), which is preferably connected to the center point of the cylindrical slider element 206. Applying a voltage to the SMA wire 212 causes the SMA wire 212 to contract, pulling the slider element 206 toward the first position in direction "A" as shown in Figure 3. As shown in Figure 5, tension is generated in the spring 210 by moving the slider element 206 in direction "A" via the contraction of the shape memory alloy wire 212. When the shape memory alloy wire 212 is relaxed and returns to its unloaded state, the spring 210 compresses, thereby pushing the slider element 206 toward the neutral position shown in Figure 4 in direction "B". In other embodiments of the present invention, other means may be used to move the slider element 206 in direction "A". For example, a solenoid may be used for this purpose.

[0057] Figure 6 is a perspective view of the fully assembled drive mechanism 200 from the opposite side, showing the rotation of the output shaft 228 in direction "D". Note that by using planetary gears, the output shaft 228 is rotated in the opposite direction to the rotation of the header element 204, which rotates in direction "C" as shown in Figure 3. Using other types of gear trains, the output shaft 220 can be rotated in the same direction as the header element 204.

[0058] Figure 7A shows a modification of the first embodiment in which the slider element 206 defines a ribbed tubular projection 230 on a surface adjacent to the spring mechanism 210 such that the legs of the spring mechanism 210 engage with the circumferential surface of the projection 230. In this embodiment, the multiple legs of the spring 210 engage with the projection 230 at different depths, as shown in Figure 7B, providing sequential engagement of the multiple legs of the spring during the operating cycle and potentially providing better control of the spring load profile. For example, the multiple legs of the spring 210 can be adjusted to provide extra stiffness at the end of the cycle.

[0059] Figure 8 shows yet another modification of the first embodiment of the present invention, in which, for example, a curved profile 802 is provided on the inclined portions of the opposing walls 304 and 308 of the zigzag-shaped trajectory defined within the channel 216, in contrast to the linear profile shown in Figure 3. A similar inclined profile may be used in the second embodiment discussed herein. The curved profile 802 allows for improved adjustment of the load profile applied to the shape memory alloy wire 212 and the output torque applied to the pump. The example with the curved profile shown in Figure 8 reduces the required force induced by the shape memory alloy wire 212 at the end of the cycle. This is useful because the shape memory alloy wire 212 is generally the weakest mechanically at the end of the cycle. Other profiles may be used instead of the curved profile 802, as long as the zigzag motion of the peg 208 in the channel 216 can be maintained by the back-and-forth motion of the slider element 206.

[0060] Figure 9 shows another embodiment of the present invention in which the interface element is equipped with a ball bearing 234. By using the ball bearing 234 instead of the peg 208 of the primary embodiment, friction is likely to be reduced, and consequently, the energy required to angularly displace the header element 204 is likely to be reduced. In this embodiment, the channel 216 in the slider element 206 is made shallow enough to form a groove 217b having a semicircular cross-sectional shape, as shown in Figure 9. Furthermore, each tab 204a of the header element 204 is configured with a substantially hemispherical recess 217a in which a ball bearing 234 is partially positioned. The diameter of the semicircular groove 217b must be slightly larger than the diameter of the ball bearing 234, and the ball bearing 234 should fit snugly into the hemispherical recess 217a. One or more of the several tabs 204a defined on the header element 204 may be configured with a hemispherical recess 217a and a ball bearing 234. To further reduce friction, it is desirable that the tabs 204a of the header element 204 and the slider element 206 do not come into contact with each other. In exemplary embodiments, the ball bearing 234 may be made of carbon-chromium steel.

[0061] Figure 10 shows a second embodiment of the present invention in which a cylindrical slider element 206 defines two zigzag-shaped trajectories, a larger trajectory 240 and a smaller trajectory 242, within a channel 216 on its circumferential surface. This embodiment may be called a dual-dosing actuator. The movement of the peg 208 through each respective trajectory provides different angular displacements of the header element 204, and therefore different rotations of the output shaft 228 for each cycle of the drive mechanism. This allows for the delivery of larger or smaller volumes of liquid drug during each cycle of the drive mechanism 200, depending on how the slider element 206 is pulled or pushed. Thus, the total desired amount of liquid drug can be delivered using as many cycles as possible that push the pin 208 through the larger trajectory 240, and the remainder of the desired amount of liquid drug is delivered by pushing the peg 208 through the smaller trajectory 242. Therefore, the second embodiment, having two orbitals 240, 242 defined within channel 216, can reduce the total number of cycles required to deliver a desired volume of liquid drug, and consequently, the total energy consumption of the drug delivery device 102. In other words, the dual-dose actuator allows the drive mechanism to deliver a specific volume of fluid using fewer shape memory alloy wire pulses, thereby reducing electrical energy consumption without increasing the minimum deliverable fluid volume.

[0062] In this embodiment, the slider element 206 has the ability to be pushed and / or pulled to a first or second position, with the slider element 206 returning to a neutral position when the force required to move the slider element 206 in either direction "A" or "B" along its radial axis (see Figures 11 and 12) is removed. As seen in Figure 10, the outer circumferential surfaces of the slider element 206 define a first zigzag track 240 and a second zigzag track 242, having an offset 244 positioned between them to guide the peg 208. Figure 10 shows a drive mechanism with the slider element 206 in the neutral position, with the peg 208 positioned in the center of the channel 216 near the offset 244.

[0063] The channel 216 on the circumferential surface of the slider element 206 defines two tracks 240, 242 along which the peg 208 can move through the channel 216. Therefore, longitudinal movement of the slider element 206 in either direction "A" or "B" results in different angular displacements of the header element 204, and thus different volumes of liquid agent supplied by the pump mechanism. Movement of the peg 208 along the larger track 240 results in a larger volume of liquid agent supplied, while movement of the peg 208 along the smaller track 242 results in a smaller volume of liquid agent supplied. For example, when the peg 208 moves along the larger track 240, the header element 204 can rotate 36°, resulting in the delivery of 0.20 units of liquid agent. However, when the peg 208 moves along the smaller track 242, the header element 204 can only move 9°, resulting in the supply of only 0.05 units of liquid agent. Therefore, to deliver 1.1 units of liquid drug, 5 cycles are required in which the peg 208 moves along the larger trajectory 240, and 2 cycles in which the peg 208 moves along the smaller trajectory 242 (5 * 0.20 + 2 * 0.05). As can be understood, the larger trajectory 240 and the smaller trajectory 242 can each be designed to provide angular displacements of the header element 204 at angles different from those described in the exemplary embodiment, and thus different volumes of liquid drug to be delivered. The ability to deliver more and less volume of liquid drug allows the drug delivery device 102 to deliver a constant volume of liquid drug using fewer cycles (e.g., wire pulses made of shape memory alloy), and thus reduces electrical energy consumption without increasing the minimum constant volume of liquid drug to be delivered. In other words, the number of strokes or pulses can be reduced compared to the single-dose actuator described above, which may require 22 strokes or pulses to deliver 1.1 units of fluid (if 0.05 units are delivered per pulse).

[0064] Figure 11 shows an example of a drive mechanism 200 that moves peg 208 along a larger track 240. The movement of the slider element 206 in direction "B" from the neutral position to the first position moves peg 208 along the inclined portion 241 of the larger track 240, thereby rotating the header element 204 over a larger angular interval. The movement of the slider element 206 back to the neutral position shown in Figure 10 moves peg 208 by engaging with the inclined surface of the triangular offset 244 closest to the larger track 240, so as to position peg 208 to engage with the next notch in the larger track 240 or the smaller track 242 during the next cycle, depending on whether the slider element 206 is moved in direction "A" or direction "B".

[0065] Figure 12 shows an example of a drive mechanism 200 that moves the peg 208 along a smaller track 242. The movement of the slider element 206 in direction "A" moves the peg 208 along the inclined portion 243 of the smaller track 242, thereby rotating the header element 204 over smaller angular intervals. The movement of the slider element 206 back to the neutral position shown in Figure 10 moves the peg 208 by engaging with the inclined surface of the triangular offset 244 closest to the smaller track 242, so as to position the peg 208 to engage with the next notch of the larger track 240 or the smaller track 242 during the next cycle, depending on whether the slider element 206 is moved in direction "A" or direction "B".

[0066] The ability to move the slider element 206 in either direction "A" or "B" requires means to apply force in both directions. In one embodiment of the present invention, two shape memory alloy wires 1301 and 1302, shown in Figure 13, can be used to provide these opposing forces. Each of the shape memory alloy wires 1301 and 1302 may be configured to move the link mechanism 1303 in opposite directions, thereby applying a tensile or compressive force to the slider element 206 to move it in either direction "A" or "B". The input mechanical advantage of the system can be adjusted by adjusting the distance between each shape memory alloy wire and the pivot point, or the distance between the pivot point and the center of the slider (i.e., a larger SMA force and a smaller SMA stroke or a smaller SMA force and a larger SMA stroke). Alternatively, depending on the type of gear train used, shape memory alloy wires 1301 and 1302 can be provided as direct connections to opposing surfaces (not shown) of the slider element 206.

[0067] In one embodiment, the slider element 206 can be returned to the neutral position via one or more springs, for example, spring 210 and / or internal spring 1401 shown in Figure 14. In other embodiments, shape memory alloy wires 1301, 1302 can be used to move the slider element 206 in direction "A" or "B" and to return the slider element 206 to the neutral position. For example, SMA wire 1301 can be used to move the slider element 206 in direction "A", and SMA wire 1302 can be used to return the slider element 206 to the neutral position. Similarly, SMA wire 1302 can be used to move the slider element 206 in direction "B", and SMA wire 1301 can be used to return the slider element 206 to the neutral position.

[0068] Figure 14 shows an alternative embodiment of either the first or second embodiment of the present invention, in which a spring 1401 is incorporated. The spring 1401 can apply either a tensile or compressive force to the slider element 206 to return it to the neutral position. The use of the internal spring 1401 can replace the use of the spring 210 shown in Figure 2.

[0069] The following embodiments relate to various pump mechanisms suitable for use in wearable drug delivery devices.

[0070] Embodiment 1 is a drive mechanism of the first embodiment, comprising a slider element arranged coaxially with a header element, wherein the slider element is cylindrical and has a channel defined around it, and the header element has one or more tabs covering a portion of the channel and one or more interface elements positioned between the slider element and the header element and extending into the channel.

[0071] Example 2 is an extension of Example 1 or any other example disclosed herein, in which the interface element is a plurality of pegs extending from each tab.

[0072] Example 3 is an extension of Example 1 or any other example disclosed herein, in which the interface element is a plurality of arranged ball bearings, the channel has a semicircular cross-section, and each tab defines a hemispherical recess in which the ball bearings are arranged.

[0073] Example 4 is an extension of Example 1 or any other example disclosed herein, in which the channel defines a zigzag trajectory so that the longitudinal movement of the slider element moves the peg through the channel, thereby causing the header element to rotate.

[0074] Embodiment 5 is an extension of Embodiment 4 or any other embodiment disclosed herein, wherein the drive mechanism further comprises a spring, and the slider element is moved from a neutral position to a first position by the application of force, and then returned to the neutral position by the action of the spring.

[0075] Example 6 is an extension of Example 5 or any other example disclosed herein, in which the drive mechanism further comprises a wire made of a shape memory alloy and connected to a slider element, and the applied force is generated by the contraction of the wire.

[0076] Embodiment 7 is an extension of Embodiment 1 or any other embodiment disclosed herein, wherein the movement of a slider element from a neutral position to a first position causes the pegs to follow one wall, and the movement of the slider element from the first position to a neutral position causes each peg to move in a zigzag trajectory within the channel as it moves parallel back and forth between the first position and the neutral position, the zigzag trajectory comprising a series of opposing inclined walls.

[0077] Example 8 is an extension of Example 7 or any other example disclosed herein, wherein the inclined portion of a series of opposing inclined walls has a linear profile.

[0078] Example 9 is an extension of Example 7 or any other example disclosed herein, wherein the inclined portion of a series of opposing inclined walls has a curved profile.

[0079] Example 10 is an extension of Example 1 or any other example disclosed herein, wherein the drive mechanism further comprises a gear train coupled to a header element.

[0080] Example 11 is an extension of Example 10 or any other example disclosed herein, wherein the gear train is a planetary gear system and the header elements are connected to the sun gear of the planetary gear system.

[0081] Embodiment 12 is an extension of Embodiment 11 or any other embodiment disclosed herein, wherein the output shaft of the planetary gear system is connected to a pump mechanism via a linkage mechanism, and the pump mechanism comprises a reservoir and a plunger that moves linearly in parallel within the reservoir by the rotation of a drive mechanism.

[0082] Example 13 is an extension of Example 5 or any other example disclosed herein, wherein the drive mechanism further comprises a housing in which a spring element is integrated.

[0083] Example 14 is an extension of Example 1 or any other example disclosed herein, wherein the movement of a slider element in a first direction causes the peg to follow a first trajectory, and the movement of the slider element in a second opposite direction causes the peg to follow a second trajectory, and the channel defines first and second zigzag trajectories therein such that the header element is displaced by different angular intervals as the peg follows the first or second trajectory through the channel.

[0084] Example 15 is an extension of Example 14 or any other example disclosed herein, in which a slider element is moved from a neutral position to either the first or second position by applying force in the first or second direction, respectively, and then the slider element returns to the neutral position.

[0085] Example 16 is an extension of Example 15 or any other example disclosed herein, in which the first and second forces are provided by the contraction of first and second wires, respectively, which are made of a shape memory alloy.

[0086] Example 17 is an extension of Example 16 or any other example disclosed herein, wherein the first and second wires are connected to a slider element via a link mechanism.

[0087] Example 18 is an extension of Example 16 or any other example disclosed herein, in which the slider element is moved from a first or second position to a neutral position by the action of a first or second spring, respectively.

[0088] Example 19 is an extension of Example 16 or any other example disclosed herein, in which the slider element moves from a first or second position to a neutral position by the action of one of a plurality of wires.

[0089] Embodiment 20 is a pump mechanism comprising a reservoir, a plunger disposed within the reservoir and configured to move longitudinally within the reservoir, a drive mechanism, and a link mechanism between the drive mechanism and the plunger, wherein the drive mechanism comprises a generally cylindrical slider element having a channel defined around it, one or more tabs arranged coaxially with the slider element and covering a portion of the channel, and a header element defining one or more interface elements extending into the channel from one or more of these tabs.

[0090] Example 21 is an extension of Example 20 or any other example disclosed herein, in which the interface element is a plurality of pegs extending from each tab.

[0091] Example 22 is an extension of Example 20 or any other example disclosed herein, in which the interface element is a positioned ball bearing, the channel has a semicircular cross-section, and each tab defines a substantially hemispherical recess in which the ball bearing is positioned.

[0092] Example 23 is an extension of Example 20 or any other example disclosed herein, in which the longitudinal motion of the slider element relative to the header element causes the peg to move through the channel along the trajectory, resulting in an angular displacement of the header element relative to the slider element, with the channel defining a zigzag trajectory.

[0093] Example 24 is an extension of Example 21 or any other example disclosed herein, wherein the movement of a slider element in a first direction causes the peg to follow a first trajectory, and the movement of the slider element in a second direction causes the peg to follow a second trajectory, and the header element defines first and second zigzag shaped trajectories within the channel such that the channel is displaced by different angular intervals as the peg follows the first or second trajectory through the channel.

[0094] Many modifications and adaptations of the present invention can be realized by those skilled in the art in which the present invention relates. The forms provided herein, including the dimensions, shapes, ratings, and specifications of various components, or the arrangement of components and descriptions of specific manufacturing processes, are illustrative and in no way intended to limit the present invention. As those skilled in the art will understand, many variations of the forms discussed herein that fall within the scope of the present invention are possible. Furthermore, it should be understood that the features of the various embodiments described herein are not mutually exclusive and can exist in various combinations and substitutions, even if such combinations or substitutions are not expressly expressed herein, without departing from the spirit and scope of the present invention. Accordingly, the methods and apparatus disclosed herein should be construed as illustrative examples and not as limiting the present invention. The scope of the present invention is defined by the following claims. Furthermore, this disclosure includes the following inventions. The first aspect is, In the drive mechanism, The aforementioned drive mechanism is A slider element that is generally cylindrical and has a channel defined on its circumferential surface, A header element arranged coaxially with the slider element, wherein the header element has one or more tabs extending from the main body portion, and the one or more tabs cover the portion of the channel defined on the circumferential surface of the slider element. A drive mechanism comprising one or more interface elements positioned between one or more tabs of one or more tabs of the header element and the slider element, the interface elements extending into the channel. The second aspect is, The interface element is a drive mechanism in a first embodiment, comprising one or more pegs, one of which extends into the channel from each of the one or more tabs. The third aspect is, The drive mechanism in the first embodiment is such that the channel has a semicircular cross-section, and the interface element comprises one or more ball bearings, each ball bearing being partially located within the channel and partially located within substantially hemispherical recesses defined within each tab. The fourth aspect is, A drive mechanism in a first embodiment, wherein the longitudinal motion of the slider element along the radial axis of the slider element with respect to the header element moves one or more interface elements through the channel, thereby causing an angular displacement of the header element with respect to the slider element, the channel defines a zigzag trajectory within it. The fifth aspect is, The drive mechanism further comprises a spring, the slider element being moved in the first longitudinal direction relative to the header element from a neutral position to a first position by a force applied in the first longitudinal direction, and the slider element then returning to the neutral position by the action of the spring, in a fourth embodiment of the drive mechanism. The sixth aspect is, The drive mechanism further comprises a wire made of a shape memory alloy connected to the slider element, and the applied force is generated by the contraction of the wire, in a fifth embodiment of the drive mechanism. The seventh aspect is, A fourth embodiment of the drive mechanism, wherein longitudinal movement of the slider element from the neutral position to the first position causes one or more interface elements to follow one of a series of opposing inclined walls, and the zigzag trajectory comprises a series of opposing inclined walls such that longitudinal movement of the slider element from the first position to the neutral position causes one or more interface elements to follow the opposing walls such that each of the interface elements moves in a zigzag trajectory within the channel when the slider element moves parallel back and forth between the first position and the neutral position. The eighth aspect is, The inclined portions of the series of opposing inclined walls are drive mechanisms in a seventh embodiment, having a straight or curved profile. The ninth aspect is, The drive mechanism in the first embodiment further comprises a gear train connected to the header element, the gear train being a planetary gear, and the header element being connected to the sun gear of the planetary gear. The tenth aspect is, The output shaft of the aforementioned planetary gear system is connected to the pump mechanism via a link mechanism. The aforementioned pump mechanism is Reservoir and, A drive mechanism in a ninth embodiment, comprising a plunger connected to the drive mechanism such that the plunger moves linearly in parallel within the reservoir by the rotation of the output shaft of the drive mechanism. The eleventh aspect is, The drive mechanism in the fifth embodiment further comprises a housing, the slider element and header element are arranged within the housing, and the spring is integrated with the housing. The twelfth aspect is, The movement of the slider element in a first longitudinal direction from a neutral position to a first position along its radial axis relative to the header element causes one or more interface elements to move through the channel by a first distance, thereby causing a first angular displacement of the header element relative to the slider element, the channel defines a first zigzag trajectory within it, The drive mechanism in the first embodiment comprises a channel that defines a second zigzag trajectory such that the movement of the slider element in a second longitudinal direction opposite to the first longitudinal direction, from a neutral position to a second position along its radial axis with respect to the header element, moves one or more interface elements through the channel by a second distance, thereby causing a second angular displacement of the header element with respect to the slider element. The 13th aspect is, The slider element is moved from the neutral position to the first position by the first applied force, and then the slider element returns to the neutral position. The slider element is moved from the neutral position to the second position by a second applied force, and the slider element then returns to the neutral position, in a twelfth embodiment of the drive mechanism. The 14th aspect is, The drive mechanism is a drive mechanism in a thirteenth embodiment, comprising a first wire made of a shape memory alloy for providing the first force and a second wire made of a shape memory alloy for providing the second force. The 15th aspect is, The first wire and the second wire are connected to the slider element via a link mechanism, forming a drive mechanism in a 14th embodiment. The 16th aspect is, The drive mechanism in the fourteenth embodiment is such that the slider element moves from the first position to the neutral position by the action of a first spring, and the slider element moves from the second position to the neutral position by the action of a second spring. The 17th aspect is, The drive mechanism in a 14th embodiment is such that the slider element moves from the first position to the neutral position by force applied by the second wire, and the slider element moves from the second position to the neutral position by force applied by the first wire. The 18th aspect is, In a pump mechanism, The aforementioned pump mechanism is A reservoir comprising a tubular structure having a first end and a second end, wherein the second end is composed of a fluid orbit; A plunger disposed within the reservoir, configured to move longitudinally parallel within the reservoir toward the second end, The drive mechanism, The drive mechanism and the plunger are provided with a link mechanism, The aforementioned drive mechanism is A slider element that is generally cylindrical and has channels defined on its circumferential surface, A header element arranged coaxially with the slider element, wherein the header element has one or more tabs extending from the main body portion, and the one or more tabs cover the portion of the channel defined on the circumferential surface of the slider element. A pump mechanism comprising one or more interface elements positioned between one or more of the one or more tabs of the header element and the slider element, the interface elements extending into the channel. The 19th aspect is, The drive mechanism in the 18th embodiment is such that the longitudinal motion of the slider element along the radial axis of the slider element with respect to the header element moves one or more interface elements through the channel, thereby causing an angular displacement of the header element with respect to the slider element, the channel defines a zigzag trajectory within it. The 20th aspect is, In drug delivery pumps, The drug delivery pump is A reservoir configured to contain a drug, A needle or cannula configured to penetrate the user's skin, A plunger disposed within the reservoir, configured to move longitudinally within the reservoir so that a certain volume of the drug is delivered through the needle or cannula; A drive mechanism equipped with a slider element, The drive mechanism and the plunger are provided with a link mechanism, The drug delivery pump comprises a drive mechanism configured to deliver a first volume of drug when the slider element is moved in a first direction, and to deliver a second volume of drug different from the first volume of drug when the slider element is moved in a second direction opposite to the first direction.

Claims

1. In the drive mechanism, The aforementioned drive mechanism is A slider element that is generally cylindrical and has a channel defined on its circumferential surface, A header element arranged coaxially with the slider element, wherein the header element has one or more tabs extending from the main body portion, and the one or more tabs cover the portion of the channel defined on the circumferential surface of the slider element. One or more interface elements positioned between one or more tabs of the header element and the slider element, comprising one or more interface elements extending into the channel, A drive mechanism in which the longitudinal motion of the slider element along the radial axis of the slider element relative to the header element moves one or more interface elements through the channel, thereby causing an angular displacement of the header element relative to the slider element, the channel defining a zigzag trajectory within it.

2. The drive mechanism according to claim 1, wherein the interface element comprises one or more pegs, one of which extends into the channel from each of the one or more tabs.

3. The drive mechanism according to claim 1, wherein the channel has a semicircular cross-section, and the interface element comprises one or more ball bearings, each ball bearing being partially located within the channel and partially located within substantially hemispherical recesses defined within each tab.

4. The drive mechanism according to claim 1, further comprising a spring, wherein the slider element is moved in the first longitudinal direction relative to the header element from a neutral position to a first position by a force applied in the first longitudinal direction, and further, the slider element is returned to the neutral position by the action of the spring.

5. The drive mechanism according to claim 4, further comprising a wire made of a shape memory alloy connected to the slider element, wherein the applied force is generated by the contraction of the wire.

6. The drive mechanism according to claim 4 or 5, wherein longitudinal movement of the slider element from the neutral position to the first position causes one or more interface elements to follow one of a series of opposing inclined walls, and the zigzag trajectory comprises a series of opposing inclined walls such that longitudinal movement of the slider element from the first position to the neutral position causes one or more interface elements to follow the opposing walls such that each of the interface elements moves in a zigzag trajectory within the channel when the slider element moves parallel back and forth between the first position and the neutral position.

7. The drive mechanism according to claim 6, wherein the inclined portions of the series of opposing inclined walls have a straight or curved profile.

8. The drive mechanism according to claim 1, further comprising a gear train connected to the header element, wherein the gear train is a planetary gear system, and the header element is connected to the sun gear of the planetary gear system.

9. The output shaft of the aforementioned planetary gear system is connected to the pump mechanism via a link mechanism. The aforementioned pump mechanism is Reservoir and, The drive mechanism according to claim 8, further comprising a plunger connected to the drive mechanism such that the plunger moves linearly in parallel within the reservoir by the rotation of the output shaft of the drive mechanism.

10. The drive mechanism according to claim 4, further comprising a housing, wherein the slider element and header element are arranged within the housing, and the one spring is integrated with the housing.

11. The movement of the slider element in a first longitudinal direction from a neutral position to a first position along its radial axis relative to the header element causes one or more interface elements to move a first distance through the channel, thereby causing a first angular displacement of the header element relative to the slider element, the channel defines a first zigzag trajectory within it, The drive mechanism according to claim 1, wherein the movement of the slider element in a second longitudinal direction opposite to the first longitudinal direction, from the neutral position to the second position, along the radial axis of the header element, moves one or more interface elements through the channel by a second distance, thereby causing a second angular displacement of the header element with respect to the slider element, the channel having defined a second zigzag trajectory therein.

12. The slider element is moved from the neutral position to the first position by the first applied force, and then the slider element returns to the neutral position. The drive mechanism according to claim 11, wherein the slider element is moved from the neutral position to the second position by a second applied force, and the slider element then returns to the neutral position.

13. The drive mechanism according to claim 12, further comprising a first wire made of a shape memory alloy for providing the first applied force and a second wire made of a shape memory alloy for providing the second applied force.

14. The drive mechanism according to claim 13, wherein the first wire and the second wire are connected to the slider element via a link mechanism.

15. The drive mechanism according to claim 13, wherein the slider element moves from the first position to the neutral position by the action of a first spring, and the slider element moves from the second position to the neutral position by the action of a second spring.

16. The drive mechanism according to claim 13, wherein the slider element moves from the first position to the neutral position by force applied by the second wire, and the slider element moves from the second position to the neutral position by force applied by the first wire.

17. In a pump mechanism, The aforementioned pump mechanism is A reservoir comprising a tubular structure having a first end and a second end, wherein the second end is composed of a fluid orbital, A plunger disposed within the reservoir, configured to move longitudinally parallel within the reservoir toward the second end, The drive mechanism, The drive mechanism and the plunger are provided with a link mechanism, The aforementioned drive mechanism is A slider element that is generally cylindrical and has channels defined on its circumferential surface, A header element arranged coaxially with the slider element, wherein the header element has one or more tabs extending from the main body portion, and the one or more tabs cover the portion of the channel defined on the circumferential surface of the slider element. One or more interface elements positioned between one or more of the tabs of the header element and the slider element, comprising one or more interface elements extending into the channel, A pumping mechanism in which the longitudinal motion of the slider element along the radial axis of the slider element relative to the header element moves one or more interface elements through the channel, thereby causing an angular displacement of the header element relative to the slider element, the channel defining a zigzag trajectory within it.

18. In drug delivery pumps, The drug delivery pump is A reservoir configured to contain a drug, A needle or cannula configured to penetrate the user's skin, A plunger disposed within the reservoir, configured to move longitudinally within the reservoir so that a certain volume of the drug is delivered through the needle or cannula; A drive mechanism equipped with a slider element, The drive mechanism and the plunger are provided with a link mechanism, A drug delivery pump comprising a drive mechanism configured to deliver a first volume of drug when the slider element is moved in a first direction, and to deliver a second volume of drug different from the first volume of drug when the slider element is moved in a second direction opposite to the first direction.

Images