Two-wheel actuator

Abstract

The present application relates to a drug delivery device drive mechanism comprising: a first ratchet having a first ratchet gear coupled to a first spur gear; a second ratchet having a second ratchet gear coupled to the second spur gear, where the first ratchet and the second ratchet are coplanar and the gear teeth of the first spur gear mesh with the gear teeth of the second spur gear; and an actuation mechanism including a pusher interface coupled to an actuator, the pusher interface having at least one pusher tab operable to physically contact the first ratchet gear.

Description

Technical Field

[0001] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 377,767, filed Sep. 30, 2022, the entire content of which is incorporated herein by reference. Technical Field

[0003] The disclosed embodiments generally relate to drug delivery. More particularly, the disclosed embodiments relate to techniques, processes, systems, and devices for delivering drugs to a user using a two-wheel actuator. Background Art

[0004] A wearable drug delivery device may include a reservoir for storing a liquid drug. A drive mechanism operates to expel the stored liquid drug from the reservoir for delivery to the user. In some cases, the drive mechanism includes a plurality of ratchets that provide the angular motion / torque required to operate the pump. However, based on this ratchet-based arrangement, the drive mechanism may occupy a relatively large volume inside the drug delivery device, thereby increasing the size of the drug delivery device and raising the cost. In addition, current drive mechanisms utilize a large amount of electrical energy stored in an energy storage device of the wearable drug delivery device.

[0005] Accordingly, there is a need for a more energy-efficient and more compact drive mechanism for a drug delivery device for expelling a liquid drug from a reservoir. Summary of the Invention

[0006] At least one aspect of the present disclosure relates to a drive mechanism for a drug delivery device as defined in claim 1. The drive mechanism for a drug delivery device may include: a first ratchet having a first ratchet gear coupled to a first spur gear; a second ratchet having a second ratchet gear coupled to a second spur gear, wherein the first ratchet and the second ratchet are coplanar, and the gear teeth of the first spur gear mesh with the gear teeth of the second spur gear; and an actuation mechanism including a pusher interface coupled to an actuator, the pusher interface having at least one pusher tab that is operable to physically contact the first ratchet gear or the second ratchet gear respectively and cause the first ratchet gear or the second ratchet gear to rotate incrementally. Alternatively, the pusher interface may physically contact the first spur gear or the second spur gear. In this case, ratchet gears are not required.

[0007] Another aspect of the present disclosure relates to a drive mechanism for a drug delivery device. The drive mechanism for the drug delivery device includes: a first ratchet having a first ratchet gear coupled to a first spur gear; a second ratchet having a second ratchet gear coupled to a second spur gear, wherein the gear teeth of the first spur gear mesh with the gear teeth of the second spur gear at an angle greater than zero degrees and less than 180 degrees; and an actuation mechanism including a pusher interface coupled to an actuator, the pusher interface having a pair of pusher tabs operable to physically contact the first ratchet gear and the second ratchet gear. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] In the drawings, the same reference numerals generally refer to the same parts throughout the different views. In the following description, various embodiments of the present disclosure will be described with reference to the following drawings, in which:

[0009] Figure 1 a schematic diagram of a drug delivery system according to an embodiment of the present disclosure is shown;

[0010] Figure 2A a schematic diagram of a drug delivery system according to an embodiment of the present disclosure is shown;

[0011] Figure 2B a perspective view of an example of a drug delivery system according to an embodiment of the present disclosure is shown; Figure 2A of the present disclosure is shown;

[0012] Figure 2C a perspective view of an example of a drive mechanism of a drug delivery system according to an embodiment of the present disclosure is shown; Figure 2A of the drug delivery system of the present disclosure is shown;

[0013] Figure 2D a perspective view of an exemplary drive mechanism according to an embodiment of the present disclosure is shown; Figure 2C of the present disclosure is shown;

[0014] Figure 3A a drive mechanism of a liquid drug delivery device according to an embodiment of the present disclosure is shown;

[0015] Figure 3B a perspective view of an actuation mechanism of a drive mechanism according to an embodiment of the present disclosure is shown; Figure 3A of the drive mechanism of the present disclosure is shown;

[0016] Figure 4A , Figure 4B a perspective view of an exemplary operation of a drive mechanism according to an embodiment of the present disclosure is shown; Figure 3A of the drive mechanism of the present disclosure is shown;

[0017] Figure 5 a drive mechanism of a liquid drug delivery device according to an embodiment of the present disclosure is shown;

[0018] Figure 6 shows a drive mechanism of a liquid drug delivery device according to an embodiment of the present disclosure;

[0019] Figure 7 shows a drive mechanism of a liquid drug delivery device according to an embodiment of the present disclosure;

[0020] Figure 8A 、 Figure 8B shows an exemplary operation of a drive mechanism of a liquid drug delivery device according to an embodiment of the present disclosure;

[0021] Figure 9 shows a drive mechanism of a liquid drug delivery device according to an embodiment of the present disclosure;

[0022] Figure 10 shows a drive mechanism of a liquid drug delivery device according to an embodiment of the present disclosure;

[0023] Figure 11 shows a drive mechanism of a liquid drug delivery device according to an embodiment of the present disclosure;

[0024] Figure 12A 、 Figure 12B shows an exemplary operation of a drive mechanism of a liquid drug delivery device according to an embodiment of the present disclosure; and

[0025] Figure 13A 、 Figure 13B shows an exemplary operation of a drive mechanism of a liquid drug delivery device according to an embodiment of the present disclosure.

[0026] The drawings are not necessarily to scale. The drawings are merely schematic and are not intended to describe the specific parameters of the present disclosure. The drawings are intended to depict exemplary embodiments of the present disclosure and should not be regarded as limiting the scope. In addition, for clarity, some elements in some of the drawings may be omitted, or some elements may not be illustrated to scale. Furthermore, for clarity, some reference numerals may be omitted in some of the drawings. Detailed Description

[0027] The systems, devices, and methods according to the present disclosure will now be described more fully hereinafter with reference to the accompanying drawings, in which one or more embodiments are shown. The systems, devices, and methods may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the method and apparatus 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.

[0028] Figure 1A simplified block diagram of an exemplary system 100 is shown. System 100 can be a wearable or on-body drug delivery device and / or an analyte sensor attached to the skin of patient 103. System 100 can include a controller 102, a pump mechanism 104 (referred to hereinafter as "pump 104"), and a sensor 108. Sensor 108 can be one or more of a glucose or other analyte monitor, such as, for example, a continuous glucose monitor, a ketone sensor, a heart rate monitor, or a blood oxygen sensor element, etc., and can be integrated into a wearable device. For example, one or more sensors 108 can be operable to measure a user's blood glucose (BG) value to generate a measured BG level signal 112. Controller 102, pump 104, and one or more sensors 108 can be communicatively coupled to each other via a wired or wireless communication path. For example, each of controller 102, pump 104, and one or more sensors 108 can be equipped with a radio frequency transceiver operable to communicate via one or more communication protocols (such as Bluetooth® etc.). As will be described in more detail herein, system 100 can also include a pump 104, the pump including a drive mechanism 106 having at least one housing 114 that defines a pump chamber 115, a channel chamber 116, an inlet channel 117, and an outlet channel 118. Drive mechanism 106 can further include an elastic sealing member 120 that encloses pump chamber 115 and a first biasing device 160 (such as, for example, a shape memory alloy (SMA) wire, etc.) operable to bias or move a plunger 124 relative to pump chamber 115, as will be described in more detail herein. In one example, drive mechanism 106, controller 109, and drug reservoir 126 can be integrated in a housing 105, which can be one or more components that can be a combination of reusable and disposable components. Housing 105 can be formed of one or more materials, such as plastic or metal, etc. System 100 can include additional components not shown or described for the sake of brevity.

[0029] Controller 102 can receive a desired BG level signal that can be a first signal indicating a desired BG level or range for patient 103. The desired BG level or range can be stored in the memory of controller 109 on pump 104, which receives it from the user interface of controller 102 or other device, or through an algorithm within controller 109 (or controller 102). One or more sensors 108 can be coupled to patient 103 and operable to measure an approximation of the user's BG level. In response to the measured BG level or value, one or more sensors 108 can generate a signal indicating the measured BG value. As shown in the example, controller 102 can also receive the measured BG level signal 112, which can be a second signal, from one or more sensors 108 via a communication path.

[0030] Based on the desired BG level and the measured BG level signal 112, the controller 102 or the controller 109 can generate one or more control signals for guiding the operation of the pump 104. For example, a control signal 119 from the controller 102 or the controller 109 can cause the pump 104 to start, or activate one or more power elements 123 operably connected to the pump 104. In the case where the first biasing device 160 is an SMA wire, the activation of the power element 123 on the SMA wire can cause the SMA wire to change shape and / or length, which in turn can cause the plunger 124 and the elastic seal member 120 to move. A specified amount of liquid drug 125 (e.g., insulin, GLP-1, pramlintide, or a combination preparation of insulin, GLP-1, or pramlintide; a chemotherapeutic drug; a blood thinner; a pain reliever; or an arthritis drug; etc.) can be drawn from the reservoir 126 into the pump chamber 115 through the inlet channel 117 in response to a pressure change caused by a change in the configuration of the elastic seal member 120 and the plunger 124. In some examples, the specified amount of the liquid drug 125 to be delivered can be determined based on the difference between the desired BG level and the actual BG level signal 112. For example, the specified amount of the liquid drug 125 can be determined as the appropriate amount of insulin to drive 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 can receive the liquid drug from the reservoir 126. The system 100 can operate as a closed-loop system, an open-loop system, or a hybrid system. In an exemplary closed-loop system, the controller 109 can guide the operation of the pump 104 without input from the user or the controller 102, and can receive the BG level signal 112 from one or more sensors 108. One or more sensors 108 can be housed within the pump 104, or can be housed in a separate device and communicate directly wirelessly with the pump 104 (e.g., with the controller 109) or with the external controller 102.

[0031] As further shown, the system 100 can include a needle deployment component 128 in communication with the controller 102 or the controller 109. Although shown separately in the figure, the needle deployment component 128 can be integrated within the pump 104. The needle deployment component 128 can include a needle and / or cannula 129 deployable to the patient 103, and can have one or more lumens and one or more holes at its distal end. The cannula 129 can form part of a fluid path that couples the patient 103 to the reservoir 126. More specifically, the inlet channel 117 can be connected to the reservoir 126 through a first fluid path component 130. The first fluid path component 130 can have any size and shape and can be made of any material. The first fluid path component 130 enables the transfer of fluid (such as the liquid drug 125 in the reservoir 126) to the drive mechanism 106.

[0032] As further shown, the outlet passage 118 can be coupled to the cannula 129 via the second fluid path component 131. The second fluid path component 131 can have any size and shape and can be made of any material. The second fluid path component 131 can be connected to the cannula 129 to allow the fluid discharged from the pump 104 to be supplied to the patient 103. The first fluid path component 130 and the second fluid path component 131 can be rigid, flexible, or a combination thereof.

[0033] The controller 102 / 109 can be implemented in hardware, software, or any combination thereof. The controller 102 / 109 can be, for example, a processor, logic circuit, or microcontroller coupled to a memory. The controller 102 / 109 can maintain the date and time, as well as provide other functions implemented by the processor (such as calculations, etc.). The controller 102 / 109 can be operable to execute an artificial pancreas (AP) algorithm (not shown in this example) stored in the memory, and the artificial pancreas (AP) algorithm enables the controller 102 / 109 to direct the operation of the pump 104. For example, the controller 102 / 109 can be operable to receive input from one or more sensors 108, where the input includes analyte level data (such as blood glucose data) or levels varying over time. Based on the analyte level data, the controller 102 / 109 can modify the behavior of the pump 104 and the resulting amount of the liquid drug 125 to be delivered to the patient 103.

[0034] The power element 123 can be a battery, a supercapacitor, a piezoelectric device, etc., for supplying power to the pump 104. In other embodiments, the power element 123 or an additional power source (not shown) can also supply power to other components of the pump 104 (such as the controller 102, the memory, one or more sensors 108, and / or the needle deployment component 128).

[0035] In an example, one or more sensors 108 can be devices communicatively coupled to the controller 102 and can be operable to measure blood glucose values at a predetermined time interval (such as approximately every 5 minutes, or every 1 minute, etc.). One or more sensors 108 can provide multiple blood glucose measurements to the AP application.

[0036] In some embodiments, when operating in a normal operating mode, pump 104 provides insulin stored in reservoir 126 to patient 103 based on information provided by one or more sensors 108 or system 100 or other functional elements of pump 104 (e.g., blood glucose measurement, target blood glucose value, on-board insulin, previous insulin delivery, time of day, day of the week, input from an inertial measurement unit, input from a global positioning system-enabled device, or input from a Wi-Fi-enabled device, etc.). For example, pump 104 can include analog circuitry and / or digital circuitry, which can be implemented at controller 102 / 109 for controlling the delivery of a drug or therapeutic agent. The circuitry for implementing controller 102 / 109 can include discrete dedicated logic and / or components, application specific integrated circuits, microcontrollers, or processors that execute software instructions, firmware, programming instructions, or programming code stored in memory, such as an AP application, or any combination thereof. For example, controller 102 / 109 can execute control algorithms and other programming code that can render controller 102 / 109 operable to cause the pump to deliver a certain dose of a drug or therapeutic agent to the user at a predetermined interval or as needed to bring the blood glucose measurement to a target blood glucose value. The magnitude and / or timing of some of the doses can be pre-programmed into the AP application by patient 103 or a third party (such as a healthcare provider, parent or guardian, manufacturer of a wearable drug delivery device, etc.) using a wired or wireless link, or can be iteratively calculated by controller 102 or controller 109, such as once every 5 minutes.

[0037] Although not shown, in some embodiments, one or more sensors 108 can include a processor, memory, sensing or measuring devices, and communication devices. The memory of one or more sensors 108 can store an instance of the AP application as well as other programming code and is operable to store data related to the AP application.

[0038] In various embodiments, the processor of one or more sensors 108 can include discrete dedicated logic and / or components, application specific integrated circuits, microcontrollers, or processors that execute software instructions, firmware, programming instructions stored in memory, or any combination thereof.

[0039] Figure 2AA simplified block diagram of another exemplary system 200 is shown. System 200 may include a controller 221, a memory 223, an AP application 229 and a delivery control application 299 stored in the memory 223, a pump mechanism 224, a communication device 226, a user interface 227, and a power supply 228. The memory 223 may be operable to store programming code and applications (including the delivery control application 299, the AP application 229) and data. The delivery control application 299 and the AP application 229 may optionally be stored on other devices.

[0040] The controller 221 may be coupled to the pump mechanism 224 and the memory 223. The controller 221 may include logic circuits, a clock, a counter or timer, and other processing circuits, and may be operable to execute programming code and applications stored in the memory 223, the applications including the delivery control application 299. The communication device 226 may be communicatively coupled to the controller 221 and may be operable to wirelessly communicate with external devices such as personal diabetes management devices or smart devices such as smartphones and / or smartwatches.

[0041] The pump mechanism 224 may be operable to deliver a drug (such as insulin) at a fixed rate or a variable rate. For example, an AP application or an AID algorithm executed on a personal diabetes management device or a smartphone may determine or know that the user's total daily insulin (e.g., single delivery and basal delivery) is 48 units per 24 hours, which may translate to an exemplary physiological basal dose rate of 1 unit per hour that can be determined according to a diabetes treatment plan (48 / 24 / 2 (assuming a basal / single ratio of 1:1)). Of course, the pump mechanism 224 may also be operable to deliver insulin at a rate different from the exemplary physiological dose rate of 1 unit per hour. In one example, the system 200 may be attached to a user (such as a patient or a diabetic patient) on the body, for example, by an adhesive (e.g., directly attached to the user's skin), and may deliver any therapeutic agent (including any drug or medicine such as insulin or morphine). In one example, the surface of the system 200 may include an adhesive (not shown) to facilitate attachment to the user. For example, the system 200 may be worn on the user's belt or in a pocket, and the liquid drug may be delivered to the user via a tube leading to the user's infusion site.

[0042] In various examples, system 200 can be an automated wearable drug delivery device. For example, system 200 can include: a reservoir 225 configured to hold a liquid drug (such as insulin); a needle and / or cannula 233 for delivering the drug into the user's body (which can be subcutaneous, intraperitoneal, or intravenous); and a pump mechanism 224 or other drive mechanism for transferring the drug from reservoir 225 through the needle or cannula 233 to the user.

[0043] The pump mechanism 224 can be fluidly coupled to the reservoir 225 and can be communicatively coupled to a controller 221 of the medical device. The pump mechanism 224 can be coupled to the reservoir 225 and is operable to output the liquid drug from the reservoir 225 via a fluid delivery path outside the cannula 233. The pump mechanism 224 can have mechanical parameters and specifications (such as pump resolution) indicating the mechanical performance of the pump mechanism. The pump mechanism 224 can also have an electrical connection to a control circuit (not shown), and the control circuit is operable to control the operation of the pump mechanism 224. Pump resolution is the fixed amount of insulin delivered by the pump mechanism 224 in a pump mechanism pulse, which is the actuation of the pump mechanism over a preset time period. Actuation can occur when power from a power source 228 is applied to the control circuit coupled to the pump mechanism 224, and the pump mechanism 224 operates to pump a fixed amount of insulin from the reservoir 225 within a preset time. Alternatively, the pump mechanism 224 can be substantially mechanical in structure and operation and utilize a mechanical energy storage device (such as a spring or other biasing member) to operate the pump mechanism 224.

[0044] Figure 2A The cannula 233 can be coupled to the reservoir 225 via a fluid delivery path 234. When the cannula 233 is inserted into the user's body, the cannula 233 can be operable to output the liquid drug to the user.

[0045] System 200 can also include a power source 228, such as a battery, supercapacitor, or piezoelectric device, etc., and the power source is operable to provide power to the pump mechanism 224 and / or other components of system 200 (such as the controller 221, memory 223, and communication device 226).

[0046] As Figure 2BAs shown, system 200 may include a plunger 202 positioned within a reservoir 225. An end portion or stem of the plunger 202 may extend outside of the reservoir 225. A pump mechanism 224 may be operable under the control of a controller 221 to cause the plunger 202 to expel fluid (such as a liquid drug (not shown)) from the reservoir 225 and into a fluid component 204 and an infusion cannula 233 by being advanced into the reservoir 225. In various examples, a pressure sensor (such as the pressure sensor shown at 222) may be integrated at any location along the entire fluid delivery path of system 200, the system including the reservoir 225, fluid delivery path components 204, and the infusion cannula 233.

[0047] The controller 221 may be implemented in hardware, software, or any combination thereof. In various examples, the controller 221 may be implemented as dedicated hardware (such as, an application specific integrated circuit (ASIC)). The controller 221 may be an integral part of system 200, may be implemented as a computational model in software, or may be implemented external to system 200 (e.g., remotely). The controller 221 may be configured to communicate with one or more sensors (e.g., Figure 1 one or more of the sensors 108).

[0048] As described above, a reservoir (such as 225) may be included in a drug delivery device to store a liquid drug (such as, insulin). For example, the reservoir 225 may be filled or partially filled with a liquid drug or a liquid drug solution. In one example, the liquid drug solution is a mixture of a liquid drug and an added preservative. The reservoir may store the liquid drug until all of the liquid drug has been dispensed (e.g., via the infusion cannula to a patient). Thus, the liquid drug (or solution) may be retained in the reservoir for a period of time (such as, 1 day, 3 days, 1 week, 2 weeks, etc.).

[0049] Figure 2C An example of a reservoir coupled to a drive mechanism 250 that may be included in the pump mechanism 224 is shown. Similarly, Figure 2DA perspective view of the drive mechanism 250 is shown. As disclosed in the examples that follow, the drive mechanism 250 (shown in more detail in the examples that follow) can include a drive wheel, a coplanar ratchet, and an actuator. In one example, a set of ratchets is attached to the drive wheel. The drive wheel can be coupled to the plunger 202 via the elongate shaft 254. At a high level, the ratchet is engaged by the actuator to incrementally drive the drive wheel and advance the plunger 202 and elongate shaft 254 into the reservoir 225. The elongate shaft 245 advances the plunger 202 to dispense the liquid drug from the reservoir 225. In one example, the pump mechanism coupler 251 is operable to connect either the first or second ratchet of the drive mechanism 250 to the drive element 252. The drive element 252 includes (or is otherwise coupled to) a lead screw 253 that is coupled to the plunger 202 (e.g., via the elongate shaft 254). The pump mechanism 224 is operable to rotate the lead screw 253 (e.g., via the drive mechanism 250) and move the plunger 202 to expel the liquid drug from the reservoir 225. In some examples, rotation of the lead screw 253 causes the elongate shaft 254 to advance within the reservoir 225, for example by providing a fixed nut assembly. Alternatively, rotation of the lead screw can be blocked (e.g., by providing a fixed connection between the lead screw and the plunger, where the plunger and reservoir have a non-circular (e.g., oval) cross-sectional shape that prevents the plunger from rotating within the reservoir). In this case, the internal threads of one of the ratchets can engage the external threads of the lead screw such that rotation of the ratchet causes linear movement of the lead screw.

[0050] Improved drive mechanisms for liquid drug delivery devices are provided herein. In at least one embodiment, the drive mechanism is a dual-wheel actuator having coplanar ratchets. In one example, the first ratchet includes a first spur gear, the gear teeth of which mesh with the gear teeth of a second spur gear of the second ratchet. In some examples, the coplanar arrangement of the first and second ratchets allows the drive mechanism to have a more compact form factor than coaxial arrangements provided in other implementations. As used herein, a coaxial arrangement refers to an arrangement in which the first and second ratchets rotate about the same axis.

[0051] Figure 3A A drive mechanism 300 of a liquid drug delivery device in accordance with aspects described herein is shown. In one example, the drive mechanism 300 is operable to cooperate with Figure 1 and Figure 2A - 2B the systems 100, 200 shown. For example, the drive mechanism 300 can be included in the pump mechanism 224 of the system 200.

[0052] The drive mechanism 300 includes a first ratchet wheel 302a and a second ratchet wheel 302b. As shown, the first ratchet wheel 302a and the second ratchet wheel 302b are coplanar. The first ratchet wheel 302a includes a first ratchet gear 304a and a first spur gear 306a. The first ratchet gear 304a may be coupled to the first spur gear 306a (e.g., via a first shaft 308a). The first ratchet gear 304a includes a first plurality of ratchet gear teeth, and the first spur gear 304a includes a first plurality of spur gear teeth. The first plurality of ratchet gear teeth and the first plurality of spur gear teeth may have different pitches and / or sizes. Similarly, the second ratchet wheel 302b includes a second ratchet gear 304b and a second spur gear 306b. The second ratchet gear 304b may be coupled to the second spur gear 306b (e.g., via a second shaft 308b). The second ratchet gear 304b includes a second plurality of ratchet gear teeth, and the second spur gear 306b includes a second plurality of spur gear teeth. The second plurality of ratchet gear teeth and the second plurality of spur gear teeth may have different pitches and / or sizes. In one example, the first plurality of spur gear teeth of the first spur gear 306a mesh with the second plurality of spur gear teeth of the second spur gear 306b.

[0053] The drive mechanism 300 includes an actuating mechanism 310. In one example, the actuating mechanism 310 is configured to mesh with the first plurality of ratchet gear teeth of the first ratchet gear 304a and the second plurality of ratchet gear teeth of the second ratchet gear 304b. In all embodiments of the present disclosure, the actuating mechanism may be, for example, a linear actuating mechanism or a rotatable actuating mechanism. As Figure 3B shown, the actuating mechanism 310 includes a pusher interface 312, an actuator arm 314, and a pivot point 316. The pusher interface 312 is coupled to a first end of the actuator arm 314, and the pivot point 316 is coupled to a second opposite end of the actuator arm 314. The pusher interface 312 includes a first pusher tab 318a and a second pusher tab 318b. In one example, the first pusher tab 318a is operable to physically contact the first plurality of ratchet gear teeth of the first ratchet gear 304a, and the second pusher tab 318b is operable to physically contact the second plurality of ratchet gear teeth of the second ratchet gear 304b. In some examples, the actuating mechanism 310 is positioned such that the pusher interface 312 is substantially perpendicular to the first ratchet wheel 302a. In other words, the pusher interface 312 may be substantially perpendicular to the gear face of the first ratchet wheel 302a (or the first ratchet gear 304a).

[0054] In some examples, the pusher interface 312 is coupled to the crimping connector 320. In other examples, the crimping connector 320 may be coupled to the actuator arm 314. The crimping connector 320 is coupled to at least one actuator (not shown) via biasing members 322, 323. In one example, the biasing members 322, 323 correspond to SMA wires. In another example, the biasing member 322 corresponds to an SMA wire and the biasing member 323 corresponds to a spring. More specifically, the SMA wire may be positioned on one side of the crimping connector 320 and connected to the crimping connector to bias the actuator arm 314 in one direction (when the SMA wire is activated), and the spring may be positioned on the other side of the crimping connector 320 and connected to the crimping connector to bias the actuator arm 314 in the opposite direction (when the SMA wire is deactivated). The at least one actuator may alternate between causing the first pusher tab 318a to contact a first plurality of ratchet gear teeth of the first ratchet gear 304a and causing the second pusher tab 318b to contact a second plurality of ratchet gear teeth of the second ratchet gear 304b. For example, the at least one actuator may pull the crimping connector 320 via the biasing member 323, thereby causing the actuator arm 314 to rotate about the pivot point 316 such that the first pusher tab 318a contacts a gear tooth of the first plurality of ratchet gear teeth. The first pusher tab 318a may be oriented perpendicular to the corresponding gear tooth (e.g., the gear tooth being contacted) of the plurality of ratchet gear teeth of the first ratchet gear 304a. Similarly, the at least one actuator may pull the crimping connector 320 via the biasing member 322, thereby causing the actuator arm 314 to rotate about the pivot point 316 such that the second pusher tab 318b contacts a gear tooth of the second plurality of ratchet gear teeth. The second pusher tab 318b may be oriented perpendicular to the corresponding gear tooth (e.g., the gear tooth being contacted) of the plurality of ratchet gear teeth of the second ratchet gear 304b.

[0055] In one example, by adjusting the distance between the pusher interface 312 (or the pusher tabs 318a, 318b) and the pivot point 316, the stroke length and / or force of the biasing members 322, 323 can be adjusted to achieve an appropriate balance for driving the ratchets 302a, 302b. In other examples, the distance between the crimping connector 320 and the pivot point 316 can be adjusted to achieve an appropriate balance.

[0056] Figure 4A and Figure 4B An exemplary operation of the drive mechanism 300 is shown. In one example, Figure 4A represents a first operating state of the drive mechanism 300, Figure 4B represents a second operating state of the drive mechanism 300.

[0057] As Figure 4AAs shown, in the first operating state, the actuation mechanism 310 is pulled (e.g., via the crimp connector 320) along the first linear direction 402. The actuator arm 314 rotates about the pivot point 316, causing the first pusher tab 318a to contact a corresponding gear tooth among the first plurality of ratchet gear teeth of the first ratchet gear 304a. The force applied by the first pusher tab 318a to the corresponding gear tooth causes the first ratchet gear 304a to rotate in the first rotational direction (e.g., clockwise). Since the first ratchet gear 304a is coupled to the first spur gear 306a, the rotation of the first ratchet gear 304a causes the first spur gear 306a to rotate in the first rotational direction. In one example, the first ratchet 302a (e.g., the first ratchet gear 304a and the first spur gear 306a) rotates about the first axis in the first rotational direction. In some examples, the first axis is parallel to the first shaft 308a.

[0058] The plurality of spur gear teeth of the first spur gear 306a apply a force to the plurality of spur gear teeth of the second spur gear 306b, which causes the second spur gear 306b to rotate in the second rotational direction (e.g., counterclockwise). Since the second ratchet gear 304b is coupled to the second spur gear 306b, the rotation of the second spur gear 306b causes the second ratchet gear 304b to rotate in the second rotational direction. In one example, the second ratchet 302b (e.g., the second ratchet gear 304b and the second spur gear 306b) rotates about the second axis in the second rotational direction. In some examples, the second axis is parallel to the second shaft 308b. The second axis may be parallel to the first axis. It should be appreciated that when the first pusher tab 318a contacts the first ratchet gear 304a (e.g., in the first operating state), the second pusher tab 318b will disengage from the second ratchet gear 304b.

[0059] As Figure 4BAs shown, in the second operating state, the actuation mechanism 310 is pulled (e.g., via the crimp connector 320) in the second linear direction 404. In some examples, the first linear direction 402 and the second linear direction 404 are opposite directions (e.g., left and right). The actuator arm 314 rotates about the pivot point 316, causing the second pusher tab 318b to contact a corresponding gear tooth among the second plurality of ratchet gear teeth of the second ratchet gear 304b. The force applied by the second pusher tab 318b to the corresponding gear tooth causes the second ratchet gear 304b to rotate about the second axis in the second rotational direction. Since the second ratchet gear 304b is coupled to the second spur gear 306b, the rotation of the second ratchet gear 304b causes the second spur gear 306b to rotate about the second axis in the second rotational direction. The plurality of spur gear teeth of the second spur gear 306b apply a force to the plurality of spur gear teeth of the first spur gear 306a, which causes the first spur gear 306a to rotate about the first axis in the first rotational direction. Since the first ratchet gear 304a is coupled to the first spur gear 306a, the rotation of the first spur gear 306a causes the first ratchet gear 304a to rotate about the first axis in the first rotational direction. It should be appreciated that when the second pusher tab 318b contacts the second ratchet gear 304b (e.g., in the second operating state), the first pusher tab 318a will disengage from the first ratchet gear 304a.

[0060] The drive mechanism 300 operates to convert the linear motion of the biasing members 322, 323 into rotational motion of the ratchets 302a, 302b. The drive mechanism 300 alternates between a first operating state and a second operating state, causing each ratchet 302a, 302b to rotate incrementally. In this way, by coupling one of the ratchets 302a, 302b to a pumping mechanism (e.g., the pump mechanism 224), the incremental rotational motion can be utilized to actuate the pump and deliver a liquid medicament to a patient. For example, the pump mechanism coupler can be operable to connect the first ratchet 302a or the second ratchet 302b to a drive element (e.g., Figure 2C the drive wheel 256). The drive element can include a lead screw (and optionally a tube nut on the lead screw) coupled to a plunger (e.g., Figure 2C the plunger 202). The drive mechanism 300 is operable to rotate the lead screw via the drive element and move the plunger to expel a liquid medicament from a reservoir or a pump chamber, etc. (e.g., Figure 2C the reservoir 225). In some examples, the size (e.g., diameter) of the ratchets 302a, 302b controls the dose provided by the pump mechanism. For example, larger ratchets 302a, 302b can enable the drive mechanism 300 to operate the pump mechanism with a higher dose resolution (i.e., a smaller dose per pulse of the pump mechanism, which can be defined as one actuation of the actuator arm 314).

[0061] As described above, the actuation mechanism 310 is actively pulled along multiple linear directions by using at least one actuator and at least one biasing member 322, 323. For example, the crimping connector 320 of the actuation mechanism 310 is actively pulled along a first linear direction 402 via the biasing member 323 and along a second linear direction 404 via the biasing member 322. In other examples, two different types of biasing members may be used such that the actuation mechanism 310 is actively pulled in one linear direction (e.g., using SMA wire) and is passively pulled in another linear direction (e.g., using a return spring).

[0062] Figure 5 Shown is a drive mechanism 500 according to aspects described herein. In one example, the drive mechanism 500 is substantially the same as the Figure 3A - 4B drive mechanism 300 except that the drive mechanism 500 includes a first biasing member 502a shown as a wire (e.g., SMA wire) and a second biasing member 502b shown as a spring. In some examples, the first biasing member 502a is an SMA wire and the second biasing member 502b is a return spring. As shown, a first end 504a of the second biasing member 502b is coupled to the crimping connector 320 of the actuation mechanism 310. A second end 504b of the second biasing member 502b may be coupled to a fixed point (e.g., an anchor point within the housing of a liquid drug delivery device).

[0063] In a first operating state, the actuation mechanism 310 is pulled along a first linear direction via the crimp connection 320 by the first biasing member 502a, thereby causing the actuation mechanism 310 (e.g., the second pusher tab 318b) to contact a corresponding gear tooth among the second plurality of ratchet gear teeth of the second ratchet gear 304b. The force applied by the actuation mechanism 310 to the corresponding gear tooth causes the second ratchet 302b (e.g., the second ratchet gear 304b and the second spur gear 306b) to rotate in a first rotational direction. The first end 504a of the second biasing member 502b is pulled along the first linear direction by the crimp connection 320 to cause the second biasing member 502b to extend. Thus, in a second operating state, the first biasing member 502a can be released (or relaxed), thereby allowing the second biasing member 502b to pull the actuation mechanism 310 along a second linear direction via the crimp connection 320. The actuation mechanism 310 (e.g., the first pusher tab 318a) contacts a corresponding gear tooth among the first plurality of ratchet gear teeth of the first ratchet gear 304a, and the force applied by the actuation mechanism 310 to the corresponding gear tooth causes the first ratchet 302a (e.g., the first ratchet gear 304a and the first spur gear 306a) to rotate in a second rotational direction. The first end 504a of the second biasing member 502b is pulled along the second linear direction by the crimp connection 320 to return the second biasing member 502b to a rest state.

[0064] The drive mechanism 500 operates to convert the linear motion of the biasing members 502a, 502b into rotational motion of the ratchets 302a, 302b. The drive mechanism 500 alternates between a first operating state and a second operating state, causing each ratchet 302a, 302b to rotate incrementally. Thus, by coupling one of the ratchets 302a, 302b to a pumping mechanism (e.g., the pump mechanism 224), the incremental rotational motion can be used to actuate the pump and deliver a liquid medicament to a patient. In some examples, due to the passive configuration of the second biasing member 502b, the drive mechanism 500 can operate at a reduced power consumption relative to other drive mechanism configurations (e.g., a drive mechanism where each biasing member consumes power).

[0065] As described above, each of the drive mechanisms 300, 500 includes a ratchet that is configured to couple (or connect) to a pumping mechanism to provide mechanical displacement for liquid medicament delivery.

[0066] Figure 6 A drive mechanism 600 of a liquid medicament delivery device according to aspects described herein is shown. In certain cases, due to the recoil between the first spur gear and the second spur gear, one of the ratchets may rotate slightly. In one example, the drive mechanism 600 is the same as except that the drive mechanism 600 includes a pawl mechanism 602 Figure 3A - 4BThe drive mechanisms 300 are substantially the same. In the illustrated example, the first ratchet 302a is coupled to the pumping mechanism (e.g., via the first shaft 308a), and the incremental rotation of the first ratchet 302a is used to actuate the pump to deliver liquid medication to a patient. Accordingly, the pawl mechanism 602 is positioned to engage the second ratchet 302b.

[0067] The pawl mechanism 602 can include, for example, a deformable cantilever beam having a sharp bend. In one example, the sharp bend is configured to rest between two gear teeth of the second plurality of spur gear teeth of the second spur gear 306b. The pawl mechanism 602 provides a stabilizing force that prevents the second ratchet 302b from freely rotating (e.g., recoiling). Assuming that the second plurality of spur gear teeth of the second spur gear 306b engage the first plurality of spur gear teeth of the first spur gear 306a, a residual force can be applied from the second spur gear 306b to the first spur gear 306a to prevent the first ratchet 302a from freely rotating. The pawl mechanism 602 is adjusted such that the stabilizing force is less than the force provided by the actuation mechanism 310. For example, when the second push tab 318b contacts a corresponding gear tooth of the second plurality of ratchet gear teeth of the second ratchet gear 304b, the stabilizing force of the pawl mechanism 602 is overcome, allowing the second spur gear 306b to rotate with the second ratchet gear 304b. Similarly, when the first push tab 318a contacts a corresponding gear tooth of the first plurality of ratchet gear teeth of the first ratchet gear 304a, the stabilizing force is overcome, resulting in the first plurality of spur gear teeth of the first spur gear 306a applying a force to the second plurality of spur gear teeth of the second spur gear 306b to rotate the second spur gear 306b.

[0068] As described above, the pawl mechanism 602 can be operable to engage the second plurality of spur gear teeth of the second spur gear 306b. However, it should be appreciated that the pawl mechanism 602 can be constructed differently. For example, the pawl mechanism 602 can be operable to engage the second plurality of ratchet teeth of the second ratchet gear 304b. In other examples, the pawl mechanism 602 can be operable to engage the first plurality of spur gear teeth of the first spur gear 306a or the first plurality of ratchet teeth of the first ratchet gear 304a. In some examples, multiple pawl mechanisms can be used. For example, a first pawl mechanism can be operable to engage the first spur gear 306a or the first ratchet gear 304a, and a second pawl mechanism can be operable to engage the second spur gear 306b or the second ratchet gear 304b. Similarly, a first pawl mechanism can be operable to engage the first spur gear 306a, and a second pawl mechanism can be operable to engage the first ratchet gear 304a. Likewise, a first pawl mechanism can be operable to engage the second spur gear 306b, and a second pawl mechanism can be operable to engage the second ratchet gear 304b.

[0069] In some examples, a gear train can be used to adjust the mechanical advantage provided by a drive mechanism. For example, instead of directly driving a pump mechanism (e.g., pump mechanism 224) from a ratchet (e.g., ratchet 302a or 302b), the pump mechanism can be driven by a ratchet-actuated gear train.

[0070] Figure 7 A drive mechanism 700 in accordance with aspects described herein is shown. In one example, the drive mechanism 700 is substantially the same as Figure 3A - 4B drive mechanism 300 except that the drive mechanism 700 includes a gear train 702. As shown, the gear train 702 is coupled to the first ratchet 302a and is actuated via rotation of the first ratchet 302a provided by an actuation mechanism 310. In other examples, the gear train 702 can be coupled to the second ratchet 302b and actuated via rotation of the second ratchet 302b. In some examples, the gear train 702 is configured as a set of interacting gears, a planetary gearbox, a harmonic gearbox, or any other suitable gear train configuration. The gear train 702 can include two or more gears that mesh (or otherwise interact) to provide a desired mechanical advantage. For example, the gear train 702 can be used to provide an increased mechanical advantage relative to the mechanical advantage directly provided by the ratchets 302a, 302b. Two or more of the gears included in the gear train 702 can have different sizes (e.g., diameters). The reduction ratio of the gear train 702 can be adjusted or tuned to increase the input torque provided to the pump mechanism. In some examples, the gear train 702 can enable the pumping mechanism to operate with an increased dose resolution (e.g., to deliver a liquid drug in smaller dose sizes). The gear train 702 can enable a reduction in the size (e.g., diameter, thickness, etc.) of the ratchets 302a, 302b. Although not shown, the drive mechanism 700 can include a pawl mechanism (e.g., pawl mechanism 602) that is operable to engage the second ratchet 302b to provide a stabilizing force to the ratchets 302a, 302b and the gear train 702.

[0071] In the above example, the actuation mechanism 310 is positioned such that the pusher interface 312 is substantially perpendicular to the first ratchet 302a. However, in other examples, the actuation mechanism can be positioned differently.

[0072] Figure 8A and Figure 8B An exemplary operation of a drive mechanism 800 of a liquid drug delivery device in accordance with aspects described herein is shown. The drive mechanism 800 is substantially the same as drive mechanism 300 except that the drive mechanism 800 includes an actuation mechanism 810 that is positioned such that the pusher interface 812 is substantially parallel to the first ratchet 302a (or the second ratchet 302b). In one example, Figure 8AIndicates the first operating state of the drive mechanism 800, Figure 8B Indicates the second operating state of the drive mechanism 800.

[0073] As Figure 8A and Figure 8B shown, the actuating mechanism 810 includes a pusher interface 812 and an actuator arm 814. In one example, the actuator arm 814 includes a first portion 814a and a second portion 814b. The pusher interface 812 is coupled between the first portion of the actuator arm 814a and the second portion of the actuator arm 814b. The pusher interface 812 includes a first pusher tab 818a and a second pusher tab 818b. The first pusher tab 818a is operable to physically contact a first plurality of ratchet gear teeth of the first ratchet gear 304a. In one example, the first pusher tab 818a extends substantially vertically from a horizontal surface of the pusher interface 812 toward the first ratchet gear 304a. Similarly, the second pusher tab 818b is operable to physically contact a second plurality of ratchet gear teeth of the second ratchet gear 304b. In one example, the second pusher tab 818b extends substantially vertically from a horizontal surface of the pusher interface 812 toward the second ratchet gear 304b. In some examples, the actuating mechanism 810 is positioned such that the pusher interface 812 is substantially parallel to the first ratchet 302a. In other words, the pusher interface 812 can be substantially parallel to the gear face of the first ratchet 302a (or the first ratchet gear 304a).

[0074] In some examples, a first portion of actuator arm 814a is coupled to a first crimp connector 820a, and a second portion of actuator arm 814b is coupled to a second crimp connector 820b. In other examples, crimp connectors 820a, 820b may be coupled to a pusher interface 812. Crimp connectors 820a, 820b are coupled to at least one actuator (not shown) via at least one biasing member (e.g., biasing members 322, 323 or biasing members 502a, 502b). In one example, the at least one biasing member causes actuator arm 814 to swing along an axis that is generally parallel to the axes of first ratchet 302a and second ratchet 302b. Actuator arm 814 is operable to reciprocate to enable pusher tabs 818a, 818b to contact ratchet gears 304a, 304b. The at least one actuator may alternate between a first plurality of ratchet gear teeth of first ratchet gear 304a contacted by first pusher tab 818a and a second plurality of ratchet gear teeth of second ratchet gear 304b contacted by second pusher tab 818b. For example, the at least one actuator may pull first crimp connector 820a via the at least one biasing member such that first pusher tab 818a contacts a gear tooth among the first plurality of ratchet gear teeth. First pusher tab 818a may be oriented parallel to a corresponding gear tooth (e.g., the contacted gear tooth) among the first plurality of ratchet gear teeth of first ratchet gear 304a. In some examples, as actuator arm 814 reciprocates, first pusher tab 818a is operable to contact an inner face and / or an outer face of the first plurality of ratchet gear teeth of first ratchet gear 304a. Similarly, the at least one actuator may pull second crimp connector 820b via the at least one biasing member such that second pusher tab 818b contacts a gear tooth among the second plurality of ratchet gear teeth. Second pusher tab 818b may be oriented parallel to a corresponding gear tooth (e.g., the contacted gear tooth) among the second plurality of ratchet gear teeth of second ratchet gear 304b. In some examples, as actuator arm 814 reciprocates, second pusher tab 818b is operable to contact an inner face and / or an outer face of the second plurality of ratchet gear teeth of second ratchet gear 304b.

[0075] As Figure 8AAs shown, in the first operating state, the actuating mechanism 810 is pulled along a first linear direction 852 via a first crimping connection 820a. The actuating mechanism 810 slides along the first linear direction 852, causing the first pusher tab 818a to contact a corresponding gear tooth among a first plurality of ratchet gear teeth of the first ratchet gear 304a. The force applied by the first pusher tab 818a to the corresponding gear tooth causes the first ratchet gear 304a to rotate in a first rotational direction (e.g., clockwise). Since the first ratchet gear 304a is coupled to the first spur gear 306a, the rotation of the first ratchet gear 304a causes the first spur gear 306a to rotate in the first rotational direction. The plurality of spur gear teeth of the first spur gear 306a apply a force to the plurality of spur gear teeth of the second spur gear 306b, which causes the second spur gear 306b to rotate in a second rotational direction (e.g., counterclockwise). Since the second ratchet gear 304b is coupled to the second spur gear 306b, the rotation of the second spur gear 306b causes the second ratchet gear 304b to rotate in the second rotational direction. It should be appreciated that when the first pusher tab 818a contacts the first ratchet gear 304a (e.g., in the first operating state), the second pusher tab 818b will disengage from the second ratchet gear 304b.

[0076] As Figure 8B shown, in the second operating state, the actuating mechanism 810 is pulled along a second linear direction 854 via a second crimping connection 820b. The actuating mechanism 810 slides along the second linear direction 854, causing the second pusher tab 818b to contact a corresponding gear tooth among a second plurality of ratchet gear teeth of the second ratchet gear 304b. The force applied by the second pusher tab 818b to the corresponding gear tooth causes the second ratchet gear 304b to rotate in the second rotational direction. Since the second ratchet gear 304b is coupled to the second spur gear 306b, the rotation of the second ratchet gear 304b causes the second spur gear 306b to rotate in the second rotational direction. The plurality of spur gear teeth of the second spur gear 306b apply a force to the plurality of spur gear teeth of the first spur gear 306a, which causes the first spur gear 306a to rotate in the first rotational direction. Since the first ratchet gear 304a is coupled to the first spur gear 306a, the rotation of the first spur gear 306a causes the first ratchet gear 304a to rotate in the first rotational direction. It should be appreciated that when the second pusher tab 818b contacts the second ratchet gear 304b (e.g., in the second operating state), the first pusher tab 818a will disengage from the first ratchet gear 304a.

[0077] In some examples, the positioning of the actuating mechanism relative to the ratchet determines the rotational direction of the ratchet. For example, in Figure 3AIn [the figure], the actuating mechanism 310 is positioned at the lower part of the ratchets 302a, 302b (e.g., below the first shaft 308a and the second shaft 308b). Thus, the first pusher tab 318a causes the first ratchet 302b to rotate clockwise, while the second pusher tab 318b causes the second ratchet 302b to rotate counterclockwise. However, in other examples, the actuating mechanism may be positioned to provide a different rotational arrangement.

[0078] Figure 9 A drive mechanism 900 of a liquid drug delivery device according to aspects described herein is shown. The drive mechanism 900 is substantially the same as the drive mechanism 300, except that the drive mechanism 900 includes an actuating mechanism 910 positioned at the top part of the ratchets 302a, 302b (e.g., above the first shaft 308a and the second shaft 308b). Thus, the first ratchet 302a rotates in a second rotational direction (e.g., counterclockwise), while the second ratchet 302b rotates in a first rotational direction (e.g., clockwise). In one example, the actuating mechanism 910 corresponds to the actuating mechanism 310 of the drive mechanism 300; however, in other examples, the actuating mechanism 1110 may correspond to the actuating mechanism 810 of the drive mechanism 800. In some examples, a configuration similar to that of the drive mechanism 900 can be achieved by rotating the drive mechanism 300 by 180 degrees.

[0079] In a first operating state, the actuating mechanism 910 can be pulled in a first linear direction via a crimp connection 920. The actuator arm 914 rotates about a pivot point 916, causing the first pusher tab 918a to contact a corresponding gear tooth among the first plurality of ratchet gear teeth of the first ratchet gear 304a. The force applied by the first pusher tab 918a to the corresponding gear tooth causes the first ratchet gear 304a to rotate in a second rotational direction (e.g., counterclockwise). Since the first ratchet gear 304a is coupled to the first spur gear 306a, the rotation of the first ratchet gear 304a causes the first spur gear 306a to rotate in the second rotational direction. The plurality of spur gear teeth of the first spur gear 306a apply a force to the plurality of spur gear teeth of the second spur gear 306b, which causes the second spur gear 306b to rotate in a first rotational direction (e.g., clockwise). Since the second ratchet gear 304b is coupled to the second spur gear 306b, the rotation of the second spur gear 306b causes the second ratchet gear 304b to rotate in the first rotational direction.

[0080] In the second operating state, the actuating mechanism 910 can be pulled along a second linear direction via the crimp connection 920. The actuator arm 914 rotates about the pivot point 916, causing the second push tab 918b to contact a corresponding one of the second plurality of ratchet gear teeth of the second ratchet gear 304b. The force applied by the second push tab 918b to the corresponding gear tooth causes the second ratchet gear 304b to rotate in a first rotational direction. Since the second ratchet gear 304b is coupled to the second spur gear 306b, rotation of the second ratchet gear 304b causes the second spur gear 306b to rotate in the first rotational direction. The plurality of spur gear teeth of the second spur gear 306b apply a force to the plurality of spur gear teeth of the first spur gear 306a, which causes the first spur gear 306a to rotate in a second rotational direction. Since the first ratchet gear 304a is coupled to the first spur gear 306a, rotation of the first spur gear 306a causes the first ratchet gear 304a to rotate in the second rotational direction.

[0081] The drive mechanism 900 alternately causes incremental rotation of the ratchets 302a, 302b between the first and second operating states. In this way, by coupling one of the ratchets 302a, 302b to a pumping system (e.g., the pump mechanism 224), the incremental rotational movement can be used to actuate the pump and deliver liquid medication to a patient.

[0082] It should be appreciated that any of the drive mechanisms described herein may include multiple linear actuation mechanisms. For example, the drive mechanism may include a first linear actuation mechanism positioned at the top portion of the ratchets 302a, 302b (e.g., above the first shaft 308a and the second shaft 308b) and a second linear actuation mechanism positioned at the bottom portion of the ratchets 302a, 302b (e.g., below the first shaft 308a and the second shaft 308b). In one example, the first linear actuation mechanism and the second linear actuation mechanism each correspond to the actuation mechanism 310 of the drive mechanism 300. In other examples, the first linear actuation mechanism and / or the second linear actuation mechanism correspond to the actuation mechanism 810 of the drive mechanism 800. Assuming that one of the ratchets is coupled to the pumping system, the first linear actuation mechanism and the second linear actuation mechanism can be controlled to operate the pumping system through bidirectional control. For example, the first linear actuation mechanism can be used to rotate the first ratchet in a first rotational direction (e.g., clockwise) and the second ratchet in a second rotational direction (e.g., counterclockwise). The rotation of the first ratchet or the second ratchet can cause the pump to dispense a liquid drug from the reservoir (e.g., by driving the plunger forward). Similarly, the second linear actuation mechanism can be used to rotate the first ratchet in the second rotational direction and the second ratchet in the first rotational direction. Reversing the rotation of the first ratchet or the second ratchet can cause the pump to return to its original state (e.g., by driving the plunger in reverse). Thus, the second linear actuation mechanism can enable the reservoir of the pumping system to be refilled for multiple uses.

[0083] Although the drive mechanism described above includes a linear actuation mechanism that engages the ratchet gear teeth of the ratchet gear, in some examples, the ratchet gear may be optional. For example, Figure 10 A drive mechanism 1000 of a liquid drug delivery device according to aspects described herein is shown. The drive mechanism 1000 includes a first ratchet 1002a, a second ratchet 1002b, and an actuation mechanism 1010. In one example, the first ratchet 1002a includes a first spur gear 1006a and the second ratchet 1002b includes a second spur gear 1006b. In some examples, the actuation mechanism 1010 is substantially the same as the actuation mechanism 810 of the drive mechanism 800 of FIG. 8, except that the actuation mechanism 1010 is configured to contact the spur gear teeth of the first spur gear 1006a and the second spur gear 1006b.

[0084] As shown, the actuation mechanism 1010 includes a pusher interface 1012 and an actuator arm 1014. In one example, the actuator arm 1014 includes a first portion 1014a and a second portion 1014b. The pusher interface 1012 is coupled between the first portion 1014a and the second portion 1014b of the actuator arm. The pusher interface 1012 includes a first pusher tab 1018a and a second pusher tab 1018b. In one example, the first pusher tab 1018a is operable to physically contact a first plurality of spur gear teeth of the first spur gear 1006a, and the second pusher tab 1018b is operable to physically contact a second plurality of spur gear teeth of the second spur gear 1006b. In some examples, the actuation mechanism 1010 is positioned such that the pusher interface 1012 is substantially parallel to the first spur gear 1006a. In other words, the pusher interface 1012 can be substantially parallel to the gear face of the first spur gear 1006a.

[0085] In some examples, the first portion of the actuator arm 1014a is coupled to a first crimp connector 1020a and the second portion of the actuator arm 1014b is coupled to a second crimp connector 1020b. In other examples, the crimp connectors 1020a, 1020b can be coupled to the pusher interface 1012. The crimp connectors 1020a, 1020b are coupled to at least one actuator (not shown) via at least one biasing member (e.g., biasing members 322 and / or 323 or biasing members 502a, 502b). The at least one actuator can alternate between causing the first pusher tab 1018a to contact the first plurality of spur gear teeth of the first spur gear 1006a and causing the second pusher tab 1018b to contact the second plurality of spur gear teeth of the second spur gear 1006b. For example, the at least one actuator can pull the first crimp connector 1020a via at least one biasing member such that the first pusher tab 1018a contacts a gear tooth among the first plurality of spur gear teeth. The first pusher tab 1018a can be oriented parallel to a corresponding gear tooth (e.g., the gear tooth being contacted) among the first plurality of spur gear teeth of the first spur gear 1006a. Similarly, the at least one actuator can pull the second crimp connector 1020b via at least one biasing member such that the second pusher tab 1018b contacts a gear tooth among the second plurality of spur gear teeth. The second pusher tab 1018b can be oriented parallel to a corresponding gear tooth (e.g., the gear tooth being contacted) among the second plurality of spur gear teeth of the second spur gear 1006b.

[0086] Depending on the location of the drive mechanism within the liquid drug delivery device, it can be advantageous to use a drive mechanism that includes a non-planar ratchet. For example, Figure 11Shows a drive mechanism 1100 including non-planar ratchets 1102a, 1102b according to aspects described herein. As shown, the angle between ratchets 1102a, 1102b is greater than 0 degrees and less than 180 degrees. In one example, the first ratchet 1102a includes a first ratchet gear 1104a and a first spur gear 1106a, while the second ratchet 1102b includes a second ratchet gear 1104b and a second spur gear 1106a. In some examples, the first spur gear 1106a and the second spur gear 1106b are configured as bevel gears. For example, the first spur gear 1106a has an inclined surface, and the second spur gear 1106b also has an inclined surface to mesh with the inclined first spur gear 1106a. The operation of the drive mechanism 1100 can be similar to that of the drive mechanism 300 in that the actuating mechanism 1110 is actuated to engage the gear teeth of the first ratchet gear 1104a (or the first spur gear 1106a) and the second ratchet gear 1104b (or the second spur gear 1106b) to rotate the ratchets 1102a, 1102b.

[0087] Depending on the configuration of the pump mechanism and / or the liquid drug delivery device, it may be advantageous to use a drive mechanism including a single ratchet. For example, Figure 12A and Figure 12B Shows a drive mechanism 1200 including a ratchet 1202 according to aspects described herein. The drive mechanism 1200 includes an actuating mechanism 1210 having a pusher interface 1212 with a single pusher tab 1218. In one example, Figure 12A represents a first operating state of the operation of the drive mechanism 1200, Figure 12B represents a second operating state of the operation of the drive mechanism 1200.

[0088] As Figure 12A shown, in the first operating state, the actuating mechanism 1210 is pulled in a first linear direction via a crimp connection 1220. In one example, the crimp connection 1220 is coupled to at least one biasing member (e.g., biasing members 322 and / or 323 or biasing members 502a, 502b). The actuator arm 1214 rotates about a pivot point 1216, causing the pusher tab 1218 to contact a corresponding gear tooth among the first plurality of ratchet gear teeth of the ratchet gear 1204. The force applied by the pusher tab 1218 to the corresponding gear tooth causes the ratchet gear 1204 to rotate in a rotational direction (e.g., counterclockwise). Since the ratchet gear 1204 is coupled to the spur gear 1206, the rotation of the ratchet gear 1204 causes the spur gear 1206 to rotate in the same rotational direction.

[0089] As Figure 12BAs shown, in the second operating state, the actuating mechanism 1210 is pulled along a second linear direction via the crimping connector 1220. The actuator arm 1214 rotates about the pivot point 1216, thereby causing the second pusher tab 1218 to disengage from the ratchet teeth of the ratchet gear 1204. In this way, the ratchet 1202 (e.g., the ratchet gear 1204 and the spur gear 1206) can be stationary in the second operating state. In some examples, the drive mechanism 1200 includes at least one pawl mechanism (e.g., the pawl mechanism 602), which is configured to stabilize the ratchet 1202 during the second operating state.

[0090] The drive mechanism 1200 alternates between a first operating state and a second operating state to cause an incremental rotation of the ratchet 1202. In this way, by coupling the ratchet 1202 to a pumping system (e.g., the pump mechanism 224), the incremental rotational movement can be used to actuate the pump and deliver a liquid medicament to a patient. It should be appreciated that the spur gear 1206 can be optional.

[0091] Figure 13A and Figure 13B An exemplary operation of an alternative drive mechanism 1300 of a liquid medicament delivery device according to aspects described herein is shown. The drive mechanism 1300 includes an actuating mechanism 1310 that is substantially coplanar with the ratchets 1302a, 1302b. In one example, Figure 13A represents a first operating state of the drive mechanism 1300, Figure 13B represents a second operating state of the drive mechanism 1300.

[0092] The actuating mechanism 1310 includes a pusher interface 1312, a linkage mechanism 1314, and an actuator arm 1316. In one example, the linkage mechanism 1314 includes a first portion 1314a coupled to the first ratchet 1302a (e.g., coupled to the first ratchet gear 1302a) and a second portion 1314b coupled to the second ratchet gear 1302b (e.g., connected to the second ratchet gear 1304b).

[0093] The pusher interface 1312 is coupled between a first portion 1314a of the linkage mechanism, a second portion 1314b of the linkage mechanism, and the actuator arm 1316. The pusher interface 1312 includes a first pusher tab 1318a and a second pusher tab 1318b. In one example, the first pusher tab 1318a is operable to physically contact a first plurality of ratchet gear teeth of the first ratchet gear 1304a, and the second pusher tab 1318b is operable to physically contact a second plurality of ratchet gear teeth of the second ratchet gear 1304b. In some examples, the actuation mechanism 1310 is positioned such that the pusher interface 1312 is substantially coplanar with the first ratchet 1302a. In other words, the pusher interface 1312 may be substantially coplanar with the gear face of the first ratchet 1302a (or the first ratchet gear 1304a).

[0094] In some examples, the actuator arm 1310 is coupled to a crimping connector (e.g., crimping connector 320). The crimping connector is coupled to at least one actuator (not shown) via at least one biasing member (e.g., biasing members 322 and / or 323 or biasing members 502a, 502b). The at least one actuator may alternate between causing the first pusher tab 1318a to contact the first plurality of ratchet gear teeth of the first ratchet gear 1304a and causing the second pusher tab 1318b to contact the second plurality of ratchet gear teeth of the second ratchet gear 1304b. For example, the at least one actuator may pull the crimping connector via the at least one biasing member such that the first pusher tab 1318a contacts the first plurality of ratchet gear teeth. Similarly, the at least one actuator may pull the crimping connector via the at least one biasing member such that the second pusher tab 1318b contacts the second plurality of ratchet gear teeth.

[0095] As Figure 13AAs shown, in the first operating state, the actuating mechanism 1310 is pulled along the first linear direction 1352 via a crimping connection. The actuating mechanism 1310 pivots in the first linear direction 1352, causing the first pusher tab 1318a to contact a corresponding gear tooth among the first plurality of ratchet gear teeth of the first ratchet gear 1304a. The force applied by the first pusher tab 1318a to the corresponding gear tooth causes the first ratchet gear 1304a to rotate in the first rotational direction (e.g., clockwise). Since the first ratchet gear 1304a is coupled to the first spur gear 1306a, the rotation of the first ratchet gear 1304a causes the first spur gear 1306a to rotate in the first rotational direction. The plurality of spur gear teeth of the first spur gear 1306a apply a force to the plurality of spur gear teeth of the second spur gear 1306b, causing the second spur gear 1306b to rotate in the second rotational direction (e.g., counterclockwise). Since the second ratchet gear 1304b is coupled to the second spur gear 1306b, the rotation of the second spur gear 1306b causes the second ratchet gear 1306b to rotate in the second rotational direction. It should be appreciated that when the first pusher tab 1318a contacts the first ratchet gear 1304a (e.g., in the first operating state), the second pusher tab 1318b will disengage from the second ratchet gear 1304b.

[0096] As Figure 13B shown, in the second operating state, the actuating mechanism 1310 is pulled along the second linear direction 1354 via a crimping connection. The actuating mechanism 1310 pivots along the second linear direction 1354, causing the second pusher tab 1318b to contact a corresponding gear tooth among the second plurality of ratchet gear teeth of the second ratchet gear 1304b. The force applied by the second pusher tab 1318b to the corresponding gear tooth causes the second ratchet gear 1304b to rotate in the second rotational direction. Since the second ratchet gear 1304b is coupled to the second spur gear 1306b, the rotation of the second ratchet gear 1304b causes the second spur gear 1306b to rotate in the second rotational direction. The plurality of spur gear teeth of the second spur gear 1306b apply a force to the plurality of spur gear teeth of the first spur gear 1306a, causing the first spur gear 1306a to rotate in the first rotational direction. Since the first ratchet gear 1304a is coupled to the first spur gear 1306a, the rotation of the first spur gear 1306a causes the first ratchet gear 1306a to rotate in the first rotational direction. It should be appreciated that when the second pusher tab 1318b contacts the second ratchet gear 1304b (e.g., in the second operating state), the first pusher tab 1318a will disengage from the first ratchet gear 1304a.

[0097] As described above, the present disclosure provides an improved drive mechanism for a drug delivery device. In at least one embodiment, the drive mechanism is a dual-wheel actuator having coplanar ratchets. In one example, the first ratchet includes a first spur gear, and the gear teeth of the first spur gear mesh with the gear teeth of a second spur gear of the second ratchet. In some examples, the coplanar arrangement of the first and second ratchets allows the drive mechanism to have a compact form factor.

[0098] The techniques described herein for a drug delivery system (e.g., system 100, system 200, or any of its components) can be implemented by hardware, software, or any combination thereof. Any component described herein can be implemented by hardware, software, or any combination thereof. For example, system 100, 200, or any of its components can be implemented by hardware, software, or any combination thereof. Software-related implementations of the techniques described herein can include, but are not limited to: firmware, special software, or any other type of computer-readable instructions executable by one or more processors. Hardware-related implementations of the techniques described herein can include, but are not limited to: integrated circuits (ICs), application-specific ICs (ASICs), field-programmable gate arrays (FPGAs), and / or programmable logic devices (PLDs). In some examples, the techniques described herein and / or any system or component described herein can be implemented using a processor that executes computer-readable instructions stored on one or more memory components.

[0099] Some examples of the disclosed apparatus may be implemented, for example, using a storage medium, a computer-readable medium, or an article of manufacture that can store instructions or instruction sets, which, if executed by a machine (i.e., a processor or a microcontroller), can cause the machine to perform the methods and / or operations according to examples of the present disclosure. Such a machine may include, for example, any suitable processing platform, computing platform, computing device, processing device, computing system, processing system, computer, or processor, etc., and may be implemented using any suitable combination of hardware and / or software. The computer-readable medium or article of manufacture may include, for example, any suitable type of storage unit, memory, storage article, storage medium, storage device, storage article, storage medium, and / or storage unit, such as a 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 disc read-only memory (CD-ROM), recordable compact disc (CD-R), rewritable compact disc (CD-RW), optical disc, magnetic media, magneto-optical media, removable memory card or disk, various types of digital versatile discs (DVDs), magnetic tape, or cassette tape, etc. The instructions may include any suitable type of code implemented using any suitable high-level, low-level, object-oriented, visual, compiled, and / or interpreted programming language, such as source code, compiled code, interpreted code, executable code, static code, dynamic code, encrypted code, and programming code, etc. The programming code embodied in a non-transitory computer-readable medium can cause a processor to perform functions, such as those described herein, when the programming code is executed.

[0100] As used herein, an algorithm or computer application for managing blood glucose levels and insulin therapy may be referred to as a system based on an “artificial pancreas” algorithm, or more generally as an artificial pancreas (AP) application. The AP application may be programming code stored in a storage device and executable by a processor, a controller, or a computer device.

[0101] Certain examples of the subject matter of the present disclosure have been described above. However, it is expressly noted that the subject matter of the present disclosure is not limited to those examples, but rather, additions and modifications to what is expressly described herein are also included within the scope of the disclosed subject matter. Moreover, it should 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 subject matter of the present disclosure, even if such combinations or permutations are not expressly set forth herein. In fact, variations, modifications, and other implementations of what is described herein will occur to those of ordinary skill in the art without departing from the spirit and scope of the disclosed subject matter. Accordingly, the disclosed subject matter should not be limited solely by the foregoing illustrative description.

[0102] In particular, although the previous embodiments have been described in connection with a first ratchet and a second ratchet, it should be understood that the actuation mechanism may also engage and drive a first spur gear and a second spur gear. In this case, the first ratchet and the second ratchet are not required, i.e., the spur gears have a dual function, namely, meshing with each other to achieve coupled rotation (in opposite directions) and cooperating with at least one actuator that drives the first spur gear and / or the second spur gear.

[0103] The program aspects of the technology can be thought of as a "product" or "article of manufacture" typically in the form of executable code and / or associated data carried or embodied on a machine-readable medium. Storage media include any or all of the tangible memories of a computer or processor, or their associated modules, such as various semiconductor memories, tape drives, and disk drives, etc., which can provide non-transitory storage for software programming at any time. It should be emphasized that providing the abstract of the present disclosure is for the reader to quickly determine the nature of the present technical disclosure. It should be understood that the submission of the abstract is not for interpreting or limiting the scope or meaning of the claims. Additionally, in the foregoing detailed description, various features are grouped together in a single example to simplify the disclosure. The method of the present disclosure should not be construed as reflecting an intention that the claimed examples require more features than those expressly recited in each claim. Rather, as reflected in the appended claims, the inventive subject matter lies in less than all the features of a single disclosed example. Accordingly, the following claims are hereby incorporated into the detailed description, where each claim stands on its own as a separate example. In the appended claims, the terms "comprising" and "therein" are used as the plain English equivalents of the respective terms "including" and "wherein". Additionally, terms such as "first", "second", and "third" are used merely as identifiers and are not intended to impose an order requirement on their objects.

[0104] Although the present invention has been described above and defined in the claims, it should be understood that the present invention may alternatively be defined according to the following embodiments:

[0105] 1. A drive mechanism for a drug delivery device, the drive mechanism for the drug delivery device comprising:

[0106] A first ratchet having a first ratchet gear coupled to a first spur gear;

[0107] A second ratchet having a second ratchet gear coupled to a second spur gear, wherein the first ratchet and the second ratchet are coplanar, and the gear teeth of the first spur gear mesh with the gear teeth of the second spur gear; and

[0108] An actuating mechanism, the actuating mechanism including a pusher interface coupled to an actuator, the pusher interface having at least one pusher tab, the at least one pusher tab being operable to physically contact the first ratchet gear.

[0109] 2. The drug delivery device drive mechanism according to embodiment 1, wherein the pusher interface is substantially perpendicular to the gear face of the first ratchet.

[0110] 3. The drug delivery device drive mechanism according to embodiment 1, wherein the pusher interface is substantially parallel to the gear face of the first ratchet.

[0111] 4. The drug delivery device drive mechanism according to one of the foregoing embodiments, wherein the at least one pusher tab of the pusher interface further comprises:

[0112] A first pusher tab operable to contact a corresponding one of a plurality of gear teeth of the first ratchet gear; and

[0113] A second pusher tab operable to contact a corresponding one of a plurality of gear teeth of the second ratchet gear,

[0114] wherein the actuator alternates between causing the first pusher tab to contact the corresponding one of the plurality of gear teeth of the first ratchet gear and causing the second pusher tab to contact the corresponding one of the plurality of gear teeth of the second ratchet gear.

[0115] 5. The drug delivery device drive mechanism according to any one of the foregoing embodiments, wherein the first ratchet rotates about a first axis in a first direction and the second ratchet rotates about a second axis in a second direction.

[0116] 6. The drug delivery device drive mechanism according to one of the foregoing embodiments, wherein the second axis is parallel to the first axis.

[0117] 7. The drug delivery device drive mechanism according to embodiment 5, wherein the first direction is opposite to the second direction.

[0118] 8. The drug delivery device drive mechanism according to one of the foregoing embodiments, wherein the first pusher tab contacts the corresponding one of the plurality of gear teeth of the first ratchet gear to cause the first ratchet to rotate about the first axis in the first direction, thereby causing the second ratchet to rotate about the second axis in the second direction.

[0119] 9. The drug delivery device drive mechanism according to one of the foregoing embodiments, wherein the second pusher tab contacts the corresponding gear tooth among the plurality of gear teeth of the second ratchet gear, so as to rotate the second ratchet around the second axis in the second direction, thereby causing the first ratchet to rotate around the first axis in the first direction.

[0120] 10. The drug delivery device drive mechanism according to one of the foregoing embodiments, wherein:

[0121] The first pusher tab is oriented perpendicular to the corresponding gear tooth among the plurality of gear teeth of the first ratchet gear, and

[0122] The second pusher tab is oriented perpendicular to the corresponding gear tooth among the plurality of gear teeth of the second ratchet gear.

[0123] 11. The drug delivery device drive mechanism according to one of the foregoing embodiments, wherein:

[0124] The first pusher tab is oriented parallel to the corresponding gear tooth among the plurality of gear teeth of the first ratchet gear, and

[0125] The second pusher tab is oriented parallel to the corresponding gear tooth among the plurality of gear teeth of the second ratchet gear.

[0126] 12. The drug delivery device drive mechanism according to one of the foregoing embodiments, the drug delivery device drive mechanism further includes:

[0127] A pawl having an edge resting between the gear teeth of the first spur gear or the second spur gear, wherein the pawl is operable to prevent free rotation of the first ratchet or the second ratchet.

[0128] 13. The drug delivery device drive mechanism according to one of the foregoing embodiments, wherein the actuating mechanism further includes:

[0129] An actuator arm coupled to the pusher interface, the actuator arm including a first end coupled to a pivot point and a second end coupled to the pusher interface, wherein the first end and the second end are opposite ends of the actuator arm.

[0130] 14. The drug delivery device drive mechanism according to one of the foregoing embodiments, wherein the pusher interface includes:

[0131] A crimping connector operable to be coupled to a shape memory alloy wire, and operation of the shape memory alloy wire causes the actuator arm to pivot relative to the pivot point.

[0132] 15. The drug delivery device drive mechanism according to one of the foregoing embodiments, wherein the actuating mechanism further comprises:

[0133] A linear actuator arm, wherein the pusher interface is coupled to the linear actuator arm, and the at least one pusher tab extends substantially vertically from a horizontal surface of the pusher interface toward the first ratchet gear, and the linear actuator arm is operable to reciprocate to bring the at least one pusher tab into contact with the first ratchet gear; and

[0134] An actuator connection point at which the actuator is coupled to an end of the linear actuator arm.

[0135] 16. The drug delivery device drive mechanism according to one of the foregoing embodiments, wherein the gear teeth of the first ratchet gear and the gear teeth of the second ratchet gear have inner and outer faces, and as the linear actuator arm reciprocates, the at least one pusher tab is operable to contact the inner face of the first ratchet gear and the inner face of the second ratchet gear.

[0136] 17. The drug delivery device drive mechanism according to one of the foregoing embodiments, wherein the gear teeth of the first ratchet gear have inner and outer faces, and the gear teeth of the second ratchet gear have inner and outer faces, and as the linear actuator arm reciprocates, the at least one pusher tab is operable to contact the outer face of the first ratchet gear and the outer face of the second ratchet gear.

[0137] 18. The drug delivery device drive mechanism according to embodiment 15, wherein the actuator connection point comprises:

[0138] A crimping connector operable to be coupled to a shape memory alloy wire, and operation of the shape memory alloy wire causes the linear actuator arm to swing along an axis substantially parallel to the first and second ratchets.

[0139] 19. The drug delivery device drive mechanism according to embodiment 15, wherein the actuator connection point comprises:

[0140] A first crimping connector operable to be coupled to a shape memory alloy wire and a second crimping connector operable to be coupled to a biasing member.

[0141] 20. The drug delivery device drive mechanism according to one of the foregoing embodiments, wherein the drug delivery device drive mechanism further comprises:

[0142] A pump mechanism coupler operable to couple the first ratchet or the second ratchet to a drive element.

[0143] 21. The drug delivery device drive mechanism according to one of the foregoing embodiments, wherein the drive element includes a lead screw coupled to a plunger, and the pump mechanism is operable to rotate the lead screw and move the plunger to expel a liquid drug from a reservoir.

[0144] 22. The drug delivery device drive mechanism according to one of the foregoing embodiments, wherein the drug delivery device drive mechanism further comprises:

[0145] A gear train coupled to the first ratchet or the second ratchet, the gear train operable to increase the input torque, the set dose resolution, or both, input to the pump mechanism.

[0146] 23. The drug delivery device drive mechanism according to one of the foregoing embodiments, wherein the actuating mechanism further comprises:

[0147] A linkage mechanism including a first portion coupled to the first ratchet and a second portion coupled to the second ratchet, wherein the pusher interface is coupled between the first portion of the linkage mechanism and the second portion of the linkage mechanism.

[0148] 24. A drug delivery device drive mechanism, the drug delivery device drive mechanism comprising:

[0149] A first ratchet having a first ratchet gear coupled to a first spur gear;

[0150] A second ratchet having a second ratchet gear coupled to a second spur gear, wherein the gear teeth of the first spur gear mesh with the gear teeth of the second spur gear at an angle greater than zero degrees and less than 180 degrees; and

[0151] An actuating mechanism including a pusher interface coupled to an actuator, the pusher interface having a pair of pusher tabs operable to physically contact the first ratchet gear and the second ratchet gear.

[0152] 25. The drug delivery device drive mechanism according to embodiment 24, wherein the first spur gear is beveled and the second spur gear is also beveled to mesh with the beveled first spur gear.

[0153] 26. The drug delivery device drive mechanism according to embodiment 24, wherein the actuating mechanism further comprises:

[0154] An actuator arm coupled to the pusher interface, the actuator arm including a first end coupled to a pivot point and a second end coupled to the pusher interface, wherein the first end and the second end are opposite ends of the actuator arm.

[0155] 27. A drug delivery device drive mechanism, the drug delivery device drive mechanism comprising:

[0156] A first spur gear and a second spur gear, wherein the gear teeth of the first spur gear mesh with the gear teeth of the second spur gear; and

[0157] An actuating mechanism, the actuating mechanism including a pusher interface having at least one pusher tab, the at least one pusher tab being operable to incrementally rotate the first spur gear and / or the second spur gear.

[0158] 28. The drug delivery device drive mechanism according to embodiment 27, wherein the pusher interface has two pusher tabs, wherein a first pusher tab is designed to incrementally rotate the first spur gear, and wherein a second pusher tab is designed to incrementally rotate the second spur gear.

[0159] 29. The drug delivery device drive mechanism according to embodiment 27 or 28, wherein the pusher interface is substantially perpendicular to the gear face of the first spur gear, or wherein the pusher interface is substantially parallel to the gear face of the first spur gear.

[0160] 30. The drug delivery device drive mechanism according to one of embodiments 27 to 28, wherein the at least one pusher tab of the pusher interface further comprises:

[0161] A first pusher tab operable to contact a corresponding one of the plurality of gear teeth of the first spur gear; and

[0162] A second pusher tab operable to contact a corresponding one of the plurality of gear teeth of the second spur gear,

[0163] wherein the actuating mechanism alternates between causing the first pusher tab to contact and advance the corresponding one of the plurality of gear teeth of the first spur gear and causing the second pusher tab to contact and advance the corresponding one of the plurality of gear teeth of the second spur gear.

[0164] 31. The drug delivery device drive mechanism according to one of embodiments 27 to 30, wherein the first spur gear rotates about a first axis in a first direction, and the second spur gear rotates about a second axis in a second direction.

[0165] 32. The drug delivery device drive mechanism according to embodiment 31, wherein the second axis is parallel to the first axis.

[0166] 33. The drug delivery device drive mechanism according to embodiment 31 or 32, wherein the first direction is opposite to the second direction.

[0167] 34. The drug delivery device drive mechanism according to one of the foregoing embodiments, wherein the first pusher tab contacts the corresponding gear tooth among the plurality of gear teeth of the first spur gear to cause the first spur gear to rotate about the first axis in the first direction, thereby causing the second spur gear to rotate about the second axis in the second direction.

[0168] 35. The drug delivery device drive mechanism according to one of embodiments 27 to 34, further comprising:

[0169] A pawl having an edge that rests between the gear teeth of the first spur gear or the second spur gear, wherein the pawl is operable to prevent free rotation of the first spur gear or the second spur gear.

[0170] 36. The drug delivery device drive mechanism according to one of embodiments 27 to 35, wherein the actuating mechanism further comprises:

[0171] An actuator arm coupled to the pusher interface, the actuator arm including a first end coupled to a pivot point and a second end coupled to the pusher interface, wherein the first end and the second end are opposite ends of the actuator arm.

[0172] 37. The drug delivery device drive mechanism according to embodiments 27 to 36, wherein the pusher interface includes:

[0173] A connector, particularly a crimp connector, the connector being coupled to at least one shape memory alloy wire, and operation of the at least one shape memory alloy wire causes the actuator arm to swing relative to the pivot point.

[0174] 38. The drug delivery device drive mechanism according to one of embodiments 27 to 37, wherein the actuating mechanism further comprises:

[0175] At least one linear actuator arm, wherein the pusher interface is coupled to the linear actuator arm, and the at least one pusher tab extends substantially vertically from a horizontal surface of the pusher interface toward the first spur gear, and the linear actuator arm is operable to reciprocate to enable the at least one pusher tab to contact the first spur gear; and

[0176] An actuator connection point at which the actuator is coupled to an end of the linear actuator arm.

[0177] 39. The drug delivery device drive mechanism according to one of embodiments 27 to 38, further comprising:

[0178] A gear train coupled to the first spur gear or the second spur gear, the gear train being operable to increase the input torque, the set dose resolution, or both, input to the pump mechanism.

[0179] 40. The drug delivery device drive mechanism according to one of embodiments 27 to 39, wherein the actuating mechanism further comprises:

[0180] A linkage mechanism including a first portion coupled to the first spur gear and a second portion coupled to the second spur gear, wherein the pusher interface is coupled between the first portion of the linkage mechanism and the second portion of the linkage mechanism.

[0181] 41. The drug delivery device drive mechanism according to one of embodiments 27 to 40, wherein the first spur gear and the second spur gear are coplanar.

[0182] 42. The drug delivery device drive mechanism according to one of embodiments 27 to 40, wherein the first spur gear is arranged at an angle greater than zero degrees and less than 180 degrees relative to the second spur gear.

[0183] 43. The drug delivery device drive mechanism according to embodiment 42, wherein the first spur gear is beveled and the second spur gear is beveled to mesh with the beveled first spur gear.

[0184] 44. A drug delivery device, the drug delivery device comprising: a reservoir for storing a liquid drug, a plunger located within the reservoir, a lead screw coupled to the plunger, and a drug delivery device drive mechanism according to one of embodiments 27 to 43, wherein the drug delivery device drive mechanism is arranged to operate the lead screw to move the plunger within the reservoir to expel the liquid drug from the reservoir.

[0185] 45. The drug delivery device according to embodiment 44, wherein the drive mechanism of the drug delivery device is arranged to rotate the lead screw.

[0186] 46. The drug delivery device according to embodiment 44 or 45, wherein the lead screw is coupled to the shaft of the first spur gear or the shaft of the second spur gear.

[0187] 47. The drug delivery device according to one of embodiments 44 to 46, wherein a non-rotating and axially fixed nut assembly engages with the external threads of the lead screw such that rotation of the lead screw results in linear movement of the lead screw.

[0188] 48. The drug delivery device according to embodiment 44, wherein the first spur gear or the second spur gear has internal threads that engage with the external threads of the lead screw, and wherein rotation of the lead screw is prevented such that rotation of the first spur gear or the second spur gear respectively results in linear movement of the lead screw.

[0189] 49. The drug delivery device according to one of embodiments 44 to 48, the drug delivery device further comprising at least one actuator for actuating the actuation mechanism.

[0190] 50. The drug delivery device according to one of embodiments 44 to 49, the drug delivery device comprising: two actuators for moving the actuation mechanism in two opposite directions, in particular two shape memory wires for moving the actuation mechanism in two opposite directions, or comprising: one shape memory wire for moving the actuation mechanism in one direction and a return spring for moving the actuation mechanism in the opposite direction.

[0191] 51. The drug delivery device according to one of embodiments 44 to 50, the drug delivery device further comprising a controller for controlling the actuation of the at least one actuator.

[0192] 52. The drug delivery device according to one of embodiments 44 to 51, the drug delivery device further comprising a power source for operating the at least one actuator and / or the controller, the power source being in particular a battery.

[0193] The foregoing description of the illustrative examples is for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure to the precise forms disclosed. Many modifications and variations are possible in light of the disclosure. The scope of the disclosure is not intended to be limited by the specific embodiments, but rather is to be limited by the appended claims. Future filed applications claiming priority to this application may claim the disclosed subject matter in a different manner and may generally include any group of one or more limitations differently disclosed herein or otherwise shown.

Claims

1. A drug delivery device drive mechanism, the drug delivery device drive mechanism comprising: A first ratchet having a first ratchet gear coupled to a first spur gear, or the first ratchet comprising a first spur gear; A second ratchet having a second ratchet gear coupled to a second spur gear, or the first ratchet comprising a second spur gear, wherein the gear teeth of the first spur gear mesh with the gear teeth of the second spur gear; And An actuating mechanism comprising a pusher interface having at least one pusher tab, the pusher tab being operable to incrementally rotate the first ratchet gear and / or the second ratchet gear.

2. The drive mechanism of the drug delivery device according to claim 1, wherein, The pusher interface has two pusher tabs, wherein a first pusher tab is designed to incrementally rotate the first ratchet gear and wherein a second pusher tab is designed to incrementally rotate the second ratchet gear.

3. The drug delivery device drive mechanism according to claim 1 or 2, wherein, The pusher interface is substantially perpendicular to the gear face of the first ratchet, or wherein the pusher interface is substantially parallel to the gear face of the first ratchet.

4. A drug delivery device drive mechanism according to one of the preceding claims, wherein, The at least one pusher tab of the pusher interface further comprises: A first pusher tab operable to contact a respective one of the plurality of gear teeth of the first ratchet gear; and A second pusher tab operable to contact a respective one of the plurality of gear teeth of the second ratchet gear, wherein the actuating mechanism alternates between causing the first pusher tab to contact and advance the respective one of the plurality of gear teeth of the first ratchet gear and causing the second pusher tab to contact and advance the respective one of the plurality of gear teeth of the second ratchet gear.

5. A drug delivery device drive mechanism according to one of the preceding claims, wherein, The first ratchet rotates about a first axis in a first direction and the second ratchet rotates about a second axis in a second direction.

6. The drug delivery device drive mechanism according to claim 5, wherein, The second axis is parallel to the first axis.

7. The drug delivery device drive mechanism according to claim 5 or 6, wherein, The first direction is opposite to the second direction.

8. A drug delivery device drive mechanism according to one of the preceding claims, wherein, The first pusher tab contacts the respective one of the plurality of gear teeth of the first ratchet gear to cause the first ratchet to rotate about the first axis in the first direction, thereby causing the second ratchet to rotate about the second axis in the second direction.

9. The drug delivery device drive mechanism according to claim 5, wherein, The second pusher tab contacts the respective one of the plurality of gear teeth of the second ratchet gear to cause the second ratchet to rotate about the second axis in the second direction, thereby causing the first ratchet to rotate about the first axis in the first direction.

10. The drug delivery device drive mechanism according to one of the preceding claims, the drug delivery device drive mechanism further comprising: A pawl having an edge that rests between the gear teeth of the first spur gear or the second spur gear, wherein the pawl is operable to prevent free rotation of the first ratchet or the second ratchet.

11. A drug delivery device drive mechanism according to one of the preceding claims, wherein, The actuating mechanism further comprises: An actuator arm, the actuator arm being coupled to the pusher interface, the actuator arm including a first end coupled to a pivot point and a second end coupled to the pusher interface, wherein the first end and the second end are opposite ends of the actuator arm.

12. A drug delivery device drive mechanism according to one of the preceding claims, wherein, The pusher interface includes: A connector, in particular a crimp connector, the connector being coupled to at least one shape memory alloy wire, and operation of the at least one shape memory alloy wire causing the actuator arm to swing relative to the pivot point.

13. A drug delivery device drive mechanism according to one of the preceding claims, wherein, The actuation mechanism further includes: At least one linear actuator arm, wherein the pusher interface is coupled to the linear actuator arm, and at least one pusher tab extends substantially vertically from a horizontal surface of the pusher interface towards the first ratchet gear, and the linear actuator arm is operable to reciprocate such that the at least one pusher tab can contact the first ratchet gear; and An actuator connection point at which the actuator is coupled to an end of the linear actuator arm.

14. The drug delivery device drive mechanism according to claim 13, wherein, The gear teeth of the first ratchet gear and the gear teeth of the second ratchet gear have inner and outer faces, and as the linear actuator arm reciprocates, the at least one pusher tab is operable to contact the inner face of the first ratchet gear and the inner face of the second ratchet gear.

15. The drug delivery device drive mechanism according to one of the preceding claims, the drug delivery device drive mechanism further including: A gear train coupled to the first ratchet or the second ratchet, the gear train being operable to increase the input torque to the pump mechanism, set the dose resolution, or both.

16. A drug delivery device drive mechanism according to one of the preceding claims, wherein, The actuation mechanism further includes: A linkage mechanism including a first portion coupled to the first ratchet and a second portion coupled to the second ratchet, wherein the pusher interface is coupled between the first portion of the linkage mechanism and the second portion of the linkage mechanism.

17. A drug delivery device drive mechanism according to one of the preceding claims, wherein, The first ratchet and the second ratchet are coplanar.

18. A drug delivery device drive mechanism according to any one of claims 1 to 16, wherein, The first spur gear is arranged at an angle greater than zero degrees and less than 180 degrees relative to the second spur gear.

19. The drug delivery device drive mechanism according to claim 18, wherein, The first spur gear is beveled, and the second spur gear is also beveled to mesh with the beveled first spur gear.

20. A drug delivery device, the drug delivery device including: A reservoir for storing a liquid drug; A plunger positioned within the reservoir; A lead screw coupled to the plunger; And The drug delivery device drive mechanism according to one of the preceding claims, wherein the drug delivery device drive mechanism is arranged to operate the lead screw to move the plunger within the reservoir to expel the liquid drug from the reservoir.

21. The drug delivery device according to claim 20, wherein, The drug delivery device drive mechanism is arranged to rotate the lead screw.

22. The drug delivery device according to claim 20 or 21, wherein, The lead screw is coupled to the shaft of the first ratchet or the shaft of the second ratchet.

23. The drug delivery device according to one of claims 20 to 22, wherein, A non-rotating and axially fixed nut assembly engages the external threads of the lead screw such that rotation of the lead screw results in linear movement of the lead screw.

24. The drug delivery device according to claim 20, wherein, The first ratchet or the second ratchet has an internal thread that meshes with the external thread of the lead screw, and wherein rotation of the lead screw is prevented such that rotation of the first ratchet or the second ratchet respectively causes linear movement of the lead screw.

25. The drug delivery device according to one of claims 20 to 24, the drug delivery device further comprising at least one actuator for actuating the actuating mechanism.

26. A drug delivery device according to one of claims 20 to 25, the drug delivery device comprising: Two actuators for moving the actuating mechanism in two opposite directions, in particular two shape memory wires for moving the actuating mechanism in two opposite directions, or comprising: one shape memory wire for moving the actuating mechanism in one direction and a return spring for moving the actuating mechanism in the opposite direction.

27. The drug delivery device according to one of claims 20 to 26, the drug delivery device further comprising a controller for controlling the actuation of the at least one actuator.

28. The drug delivery device according to one of claims 20 to 27, the drug delivery device further comprising a power source for operating the at least one actuator and / or the controller, the power source being in particular a battery.

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