Mechanism for providing variable fill capacity for a fluid reservoir and pump

Abstract

Various embodiments of a clutch mechanism applicable to a dual reservoir pump mechanism for a drug delivery device are disclosed, which clutch mechanism functions to allow linear movement of one of the two reservoirs during the filling process and then connect the reservoirs together so that one can be driven relative to the other by a lead screw or other drive mechanism.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Patent Application No. 63 / 375,986, filed September 16, 2022, the contents of which are incorporated herein by reference in their entirety. [Background technology]

[0002] Many conventional automated drug delivery (ADD) systems are well known, including, for example, wearable drug delivery devices. The drug delivery device can be designed to deliver any type of liquid drug to a user. In certain embodiments, the drug delivery device may be, for example, an OmniPod® drug delivery device manufactured by Insulet, Inc. of Acton, Massachusetts. The drug delivery device may be a drug delivery device described in U.S. Pat. No. 7,303,549, U.S. Pat. No. 7,137,964, or U.S. Pat. No. 6,740,059, each of which is incorporated herein by reference in its entirety.

[0003] The drug delivery device typically has a positive displacement pump mechanism. The pump mechanism typically includes a reservoir for storing a liquid drug. The liquid drug stored in the reservoir can be delivered to a user by using a drive plunger that translates longitudinally through the reservoir to force the drug out of the reservoir and expel the liquid drug through a fluid port defined in the reservoir. The plunger can be translated longitudinally through the reservoir, for example, by a rigidly coupled lead screw that pushes the plunger forward during pumping. When the reservoir is filled, the lead screw moves rearward with the plunger. The lead screw extends beyond the back of the plunger a distance equal to the plunger stroke plus an additional amount to allow engagement with the drive mechanism. This creates space efficiency constraints when scaling the design. As the plunger stroke increases, the lead screw length must also increase by the same amount. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] U.S. Patent No. 7,303,549 [Patent Document 2] U.S. Patent No. 7,137,964 [Patent Document 3] U.S. Patent No. 6,740,059 Summary of the Invention [Problem to be solved by the invention]

[0005] It would be desirable to use space more efficiently and allow variable amounts of drug to be inserted into the reservoir. [Means for solving the problem]

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

[0007] In wearable intracorporeal devices, it is desirable to keep the pump mechanism, as well as the entire drug delivery device, as small as possible to minimize impact on the wearer. Additionally, because such drug delivery devices are typically powered by an on-board battery, it is desirable to minimize the power required to operate the device. To conserve space within the housing of the drug delivery device, the positive displacement pump mechanism may employ a dual-reservoir configuration with a relatively large outer reservoir and a relatively small inner reservoir, the inner reservoir having a cross-sectional shape slightly smaller than the outer reservoir, and the inner reservoir may use a design that allows linear movement through the outer reservoir and acts as a plunger for the outer reservoir. The two reservoirs are in fluid communication with each other via a rigid hollow rod that is disposed between the inner and outer reservoirs and supports a static plunger against the inner reservoir, such that linear movement of the inner reservoir into the outer reservoir forces fluid from the outer reservoir through the hollow rod and into the inner reservoir. A static plunger in the inner reservoir acts to force fluid out of the inner reservoir through the fluid exit port as the inner reservoir is linearly displaced into the outer reservoir. Some examples of dual reservoir pumping mechanisms are shown in U.S. Provisional Patent Application No. 63 / 304,270, filed January 8, 2022, the contents of which are incorporated herein in their entirety.

[0008] In many cases, the reservoirs of medication delivery devices are filled by the user and can be filled with variable amounts of insulin. After the reservoirs are filled, they must be engaged with a drive unit to perform pumping. In dual-reservoir configurations using a telescoping reservoir assembly, the drive unit is typically located next to the reservoirs. During filling, one of the two reservoir bodies moves linearly while the other remains fixed (stationary). To deliver the liquid medication, the two reservoir bodies must effectively move toward each other, which can be done by moving one of the two reservoir bodies while the other remains stationary. However, during filling, it is desirable that the moving reservoir is not coupled to the drive mechanism, driven by the pressure of the incoming liquid medication, and not used by the drive mechanism, allowing the moving reservoir to move freely.

[0009] Several alternative embodiment mechanisms are disclosed herein that provide a dual reservoir pump mechanism for pumping after the reservoirs have been filled with a variable amount of liquid medication. In exemplary embodiments, the liquid medication can be insulin, GLP-1, pramlintide, morphine or other pain medication, blood pressure medication, joint medication, chemotherapy medication, fertility medication, etc., or a co-formulation of two or more of GLP-1, pramlintide, and insulin.

[0010] In some embodiments disclosed herein, a drive mechanism is coupled to the inner reservoir of a dual reservoir configuration, and the outer reservoir moves linearly during the filling process, after which the outer reservoir is fixed relative to the housing of the drug delivery device by a clutch mechanism, thereby preventing further movement of the outer reservoir during pumping of the liquid drug.

[0011] In other embodiments, the outer reservoir body is fixed relative to the housing of the drug delivery device, and the inner reservoir body is decoupled from the drive mechanism during the filling process to allow linear movement of the inner reservoir, which is then coupled to the inner reservoir via a clutch mechanism.

[0012] In the drawings, where reference is made to the drawings, like reference numerals generally refer to the same parts throughout the different views. In the following description, various embodiments of the present invention are described with reference to the following drawings: [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 shows a functional block diagram of an exemplary system suitable for use with the apparatus disclosed herein. [Figure 2] Figures 2(a)-2(b) show a first embodiment of the invention, in which the external reservoir moves linearly during the filling process and is then fixed relative to the housing of the medication delivery device by a clutch mechanism. [Figure 3] Figures 3(a)-3(b) show an embodiment of a clutch mechanism comprising a lever and brake pads that engage an external reservoir. [Figure 4] FIG. 4(a) shows an embodiment of the clutch mechanism with mating sheets of Velcro®, and FIG. 4(b) shows an embodiment of the clutch mechanism with mating sheets of contact-activated adhesive. [Figure 5] FIG. 5 illustrates one embodiment of a clutch mechanism that includes a clamp disposed around the outer surface of the outer reservoir. [Figure 6] 6(a)-6(b) show an embodiment of a clutch mechanism that uses guy ropes. [Figure 7] Figures 7(a)-7(b) show an embodiment of a clutch mechanism that uses one or more bistable mechanisms. [Figure 8] 8(a)-8(b) show a second embodiment of the present invention, in which the outer reservoir is fixed to the housing of the drug delivery device and the inner reservoir is decoupled from the drive mechanism during the filling process to allow movement of the inner reservoir, and then coupled to the drive mechanism via a clutch mechanism. The clutch mechanism herein comprises a torsion spring that threads a tube nut onto a lead screw. [Figure 9]Figures 9(a)-9(b) show an embodiment of the clutch mechanism using a spring-driven collet. [Figure 10] Figures 10(a)-10(c) show an embodiment of a clutch mechanism that utilizes frictional engagement between the tube nut and the lead screw. [Figure 11] FIG. 11 illustrates an embodiment clutch mechanism utilizing a lead screw having a longitudinal non-threaded notch defined thereon. [Figure 12] 12(a)-12(b) illustrate one embodiment of the clutch mechanism that utilizes a clamp coupled to the internal reservoir for engagement with the lead screw. [Figure 13] Figures 13(a)-13(b) show one embodiment of a clutch mechanism that utilizes a spring-actuated wedge to engage the lead screw. [Figure 14] Figures 14(a)-14(c) show an embodiment of the clutch mechanism that utilizes a spring-actuated clamp to engage the lead screw. [Figure 15] FIG. 15 illustrates an embodiment clutch mechanism that utilizes a torsion spring to engage the lead screw. [Figure 16] Figures 16(a)-16(c) illustrate one embodiment of the clutch mechanism utilizing a spring-actuated clamp that is placed on the exterior surface of the tube nut and connected to the internal reservoir. [Figure 17] Figures 17(a)-17(b) show a second embodiment clutch mechanism that utilizes a spring-actuated clamp that is positioned on the exterior surface of the tube nut and connected to the internal reservoir. [Figure 18] Figures 18(a)-18(c) show an embodiment clutch mechanism that utilizes a spring-activated clamp connected to a tube nut that engages a rod connected to the internal reservoir. [Figure 19] Figures 19(a)-19(b) show an embodiment clutch mechanism that utilizes a spring-driven collet connected to a tube nut that engages a rod connected to the internal reservoir. [Figure 20]Figures 20(a)-20(b) illustrate one embodiment of the clutch mechanism that utilizes a two-body torsion spring that is connected to the rod of the internal reservoir and to the tube nut. DETAILED DESCRIPTION OF THE INVENTION

[0014] The present invention provides various systems, components, and methods for transferring a liquid medication from a liquid reservoir in a medication delivery device to a patient interface, such as a needle or cannula. The embodiments described herein offer one or more advantages over conventional prior art systems, components, and methods, namely, an overall smaller packaging area for the medication delivery device.

[0015] Various embodiments of the present invention include systems and methods for delivering medication to a user using a medication delivery device, either autonomously or according to wireless signals received from an electronic device. In various embodiments, the electronic device may be a smartphone, a smart watch, a smart necklace, a user device with a module attached to the medication delivery device, or any other type or kind of electronic device that can be carried by or worn on the user's body and that executes an algorithm to calculate the number (time) and dosage of medication deliveries.

[0016] For example, the user device may run an "artificial-pancreas" (AP) algorithm that calculates the frequency and dosage of insulin deliveries. The user device may also communicate with a sensor, such as a glucose sensor or continuous glucose monitor (CGM), that collects information about the user's physical characteristics or condition, such as glucose levels. The sensor may be located in or on the user's body and may be part of the drug delivery device or may be a separate device.

[0017] Alternatively, the medication delivery device may communicate with the sensor instead of or in addition to communication between the sensor and the user device. This communication may be direct (e.g., if the sensor is integrated with or otherwise part of the medication delivery device) or remote / wireless (e.g., if the sensor is located in a housing separate from the medication delivery device). In these embodiments, the medication delivery device includes computer hardware (e.g., processor, memory, firmware, etc.) that executes some or all of the algorithms that calculate the time (frequency) and dosage of medication delivery.

[0018] 1 shows a functional block diagram of an exemplary drug delivery system 100 suitable for implementing the systems and methods described herein. The drug delivery system 100 may implement drug delivery algorithms (and / or provide functionality), such as for artificial pancreas (AP) applications, to manage or control the automatic delivery of a drug or medication, such as insulin, to a user (e.g., to maintain normal blood glucose levels—euglycemia—in the blood). The drug delivery system 100 may be an automatic drug delivery system that may include a drug delivery device 102 (which may be wearable), an analyte sensor 108 (which may be wearable), and a user device 105 (which may be wearable).

[0019] The drug delivery system 100 may also include, in any example, an accessory device 106, such as a smart watch, personal assistant device, insulin smart pen, etc., that can communicate with other components of the system 100 via either wired or wireless communication links 191-193.

[0020] User Device The user device 105 may be a computing device such as a smartphone, smartwatch, tablet, personal diabetes management (PDM) device, dedicated diabetes care management device, etc. For example, the user device 105 may have a processor 151, device memory 153, a user interface 158, and a communications interface 154. The user device 105 may also include analog and / or digital circuitry that may be implemented as the processor 151 to execute processes based on program code stored in the device memory 153, such as a user application 160 incorporating a drug delivery algorithm (MDA) 161 for managing the user's blood glucose levels, to control delivery of medications, drugs, or therapeutic agents to the user, and to provide other functions such as calculating carbohydrate compensation doses, correction bolus doses, etc., as described below. The user device 105 may be used to activate, deactivate, trigger, needle / cannulate, program, adjust settings, and / or control operations of the medication delivery device 102 and / or analyte sensor 103 and optional smart accessory device 106.

[0021] The processor 151 may also be configured to execute programming code stored in the device memory 153, such as a user application 160. The user application 160 may be a computer application operable to deliver medication based on data received from the analyte sensor 103, the cloud-based service 111, and / or the user device 105 or any selected accessory device 106. The memory 153 may also store programming code for operating a user interface 158 (e.g., a touchscreen device, a camera, etc.), a communication interface 154, etc. When executing the user application 160, the processor 151 may be configured to implement metrics and notifications regarding meal intake, blood glucose measurements, etc. The user interface 158 is under the control of the processor 151 and may be configured to present a graphical user interface, such as to allow for input of meal announcements, adjusting setting selections, etc., as described herein.

[0022] In a specific example, when the user application 160 includes the MDA 161, the processor 151 is also configured to execute a diabetes treatment plan (which may be stored in memory) managed by the user application 160. In addition to the functions described above, when the user application 160 is for artificial pancreas (AP) use, it may further provide functionality for determining carbohydrate compensation doses, correction bolus doses, and determining real-time basal doses according to the diabetes treatment plan. Furthermore, as the MDA 161, the user application 160 provides the functionality for outputting signals to the drug delivery device 102 via the communication interface 154 to deliver the determined bolus and / or basal doses.

[0023] Communications interface 154 may include one or more transceivers operating according to one or more radio frequency protocols. In one embodiment, the transceivers may comprise a cellular transceiver and a Bluetooth transceiver. Communications interface 154 may be configured to receive and transmit signals containing information usable by user application 160.

[0024] The user device 105 may further include one or more output devices 155, which may be, for example, speakers or vibration transducers, for providing various signals to the user.

[0025] Drug Delivery Devices In various exemplary embodiments, the medication delivery device 102 can have a reservoir 124 and a drive mechanism 125 controllable by a controller 121, which executes a medication delivery algorithm (MDA) 129 stored in memory 123 and can perform some or all of the functions of the AP application described above, such that the user device 105 may not need to perform medication delivery and control on the medication delivery device 102. Alternatively, the controller 121 can act to control the reservoir 124 and the drive mechanism 125 based on signals received from a user application 160 executing on the user device 105 and communicated to the medication delivery device 102 via a communication link 194. The drive mechanism 125 can, for example, operate to translate a plunger longitudinally through the reservoir to force liquid medication through a fluid exit port and into the needle / cannula 186. Alternatively, other types of drive mechanisms can be used.

[0026] The reservoir 124 may comprise a dual reservoir, as shown in subsequent figures, with two bodies each containing a drug and movable relative to one another. In alternative embodiments, the drug delivery device 102 may have an optional second or additional reservoir 124-2 and a second drive mechanism 125-2 that allows for independent delivery of two different liquid drugs. The reservoir 124-2 may also be a dual reservoir, as depicted in subsequent figures. By way of example, the reservoir 124 may be filled with insulin, and the reservoir 124-2 may be filled with glucagon, pramlintide, or GLP-1. In some embodiments, each of the reservoirs 124, 124-2 may be configured with a separate drive mechanism 125, 125-2 that may be individually controllable by the controller 121 under the control of the MDA 129. Both reservoirs 124, 124-2 may be connected to a common needle / cannula 186.

[0027] The medication delivery device 102 may optionally be configured with a user interface 127 that provides means for receiving input from a user and for outputting information to the user. The user interface 127 may comprise, for example, light emitting diodes, buttons on the housing of the medication delivery device 102, an acoustic transducer, a microdisplay, a microphone, an accelerometer for detecting device movement or user gestures (e.g., tapping on the housing of the device), or any other type of interface device configured to allow a user to input information and / or enable the medication delivery device 102 to emit information for presentation to the user (e.g., an alarm signal, etc.).

[0028] The medication delivery device 102 has a patient interface 186 for mating with a user to deliver the liquid medication. The patient interface may be, for example, a needle or cannula for delivering the medication into the user's body (which may be subcutaneous, intraperitoneal, or intravenous). The medication delivery device 102 also has a mechanism for inserting the needle / cannula 186 into the user's body, which may be integral to the medication delivery device 102 or may be attachable thereto. The insertion mechanism, in one embodiment, may comprise an actuator that inserts the needle / cannula 186 beneath the user's skin and then retracts the needle, leaving the cannula in place. The actuator may be triggered by the user device 105 or may be a manually fired mechanism that includes a spring or other energy storage mechanism that causes the needle / cannula 186 to pierce the user's skin.

[0029] In one embodiment, the medication delivery device 102 has a communication interface 126, which may be a transceiver operating according to one or more radio frequency protocols such as Bluetooth, Wi-Fi, near field communication, cellular, etc. The controller 121 may communicate with the user device 105 and the analyte sensor 108, for example, via the communication interface 126.

[0030] In some embodiments, the drug delivery device 102 may include one or more sensors 184. The sensors 184 may include one or more of a pressure sensor, a power sensor, etc., communicatively coupled to the controller 121 and providing various signals. For example, the pressure sensor may be configured to provide an indication of fluid pressure detected in the fluid path between the patient interface 186 and the reservoir 124. The pressure sensor may be coupled to or integrated with an actuator for inserting the patient interface 186 into the user. In one example, the controller 121 may be operable to determine a rate of drug infusion based on the indication of fluid pressure. The rate of drug infusion may be compared to an infusion rate threshold, and the result of this comparison may be usable in determining an insulin payload (IOB) or total daily insulin (TDI) amount. In one embodiment, the analyte sensor 108 may be integrated with the drug delivery device 102.

[0031] The drug delivery device 102 further includes a power source 128, such as a battery, a piezoelectric device, an energy harvesting device, etc., for powering the control unit 121, the memory 123, the drive mechanism 125, and / or other components of the drug delivery device 102.

[0032] The medication delivery device 102 may be configured to implement and perform the processes required to deliver multiple doses of medication to a user without input from the user device 105 or optional accessory device 106. As will be described in more detail, the MDA 129 may be operable to determine, for example, the amount of insulin to be delivered, IOB, remaining insulin, etc., and to cause the controller 121 to actuate the drive mechanism 125 to deliver medication from the reservoir 124. The MDA 129 may obtain input data received from the analyte sensor 108 or a user application 160.

[0033] Reservoirs 124, 124-2 may be configured to store a drug, medication, or therapeutic agent suitable for automated delivery as described above.

[0034] The drug delivery device 102 may be a wearable device that can be attached to the body of a user, such as a patient or diabetic, at an attachment location and can deliver any therapeutic agent, including any drug or medication, such as insulin, to the user at or around the attachment location. The surface of the drug delivery device 102 may have an adhesive to facilitate attachment to the user's skin.

[0035] When the drug delivery device 102 is configured to communicate with an external device, such as a user device 105 or an analyte sensor 108, the drug delivery device 102 can receive signals from the user device 105 or the analyte sensor 108 via a wired or wireless link 194. A controller 121 of the drug delivery device 102 can receive and process the signals from the respective external device and effectuate delivery of drugs to the user in accordance with a diabetes treatment plan or other drug delivery regimen.

[0036] Accessory Devices The optional accessory device 107 may be a wearable smart device, such as a smart watch (e.g., an Apple Watch®), smart glasses, smart jewelry, a global positioning system (GPS)-enabled wearable fitness device, smart clothing, etc. The accessory device 106 may alternatively be a smart insulin pen that manages blood glucose levels and cooperates with the medication delivery device 102 in treating the user's diabetes. Like the user device 105, the accessory device 106 may also be configured to perform various functions, including controlling or communicating with the medication delivery device 102. For example, the accessory device 106 may have a communications interface 174, a processor 171, a user interface 178, and memory 173. The user interface 178 may be a graphical user interface presented on a touchscreen display of the smart accessory device 107. The memory 173 may store programming code for operating various functions of the smart accessory device 107, as well as an instance of the user application 160 or a simplified version of the user application 160 with reduced functionality. In some examples, the accessory device 107 may also have various types of sensors.

[0037] Analyte Sensor The analyte sensor 108 may include a controller 131 , a memory 132 , a detection / measurement device 133 , an optional user interface 137 , a power / energy harvesting circuit 134 , and a communication interface 135 .

[0038] The analyte sensor 108 may be communicatively coupled to the processor 151 of the management device 105 or controller 121 of the medication delivery device 102. The memory 132 may be configured to store information and programming code 136. The analyte sensor 108 may be configured to detect one or more different analytes, such as glucose, lactate, ketone, uric acid, sodium, potassium, or alcohol level, and output a detection result, such as a measurement value. In an exemplary embodiment, the analyte sensor 108 may be configured as a continuous glucose monitor (CGM) for measuring blood glucose levels at predetermined time intervals, such as every five minutes or every minute. The communication interface 135 of the analyte sensor 108 may include circuitry operating as a transceiver to communicate the measured blood glucose level to the user device 105 via the wireless link 195 or to the medication delivery device 102 via the wireless communication link 115. Although referred to herein as the analyte sensor 108, the detection / measurement unit 133 of the analyte sensor 108 may include one or more additional sensing elements, such as a glucose measuring element, a heart rate monitor, or a pressure sensor. The controller 131 may include discrete dedicated logic and / or components, application specific integrated circuits, microcontrollers or processors that execute software instructions, firmware, programming instructions stored in a memory (such as memory 132), or any combination thereof.

[0039] Similar to the controller 121 of the medication delivery device 102, the controller 131 of the analyte sensor 108 may be operable to perform many functions. For example, the controller 131 may be configured by programming code 136 to manage the collection and analysis of data detected by the detection and measurement device 133.

[0040] 1 as being separate from the drug delivery device 102, in various embodiments the analyte sensor 108 and the drug delivery device 102 may be incorporated into the same unit. That is, in various embodiments the analyte sensor 108 may be part of and integral with the drug delivery device 102, and may be contained within the same housing as or attachable to the drug delivery device 102. In such an exemplary configuration, the controller 121 may independently perform the functions required for proper delivery of the drug without any external input from the user device 105, the cloud-based service 111, another sensor (not shown), the optional accessory device 106, etc.

[0041] Cloud-based services The medication delivery system 100 can communicate with or receive services from a cloud-based service 111. The services provided by the cloud-based service 111 can have a data memory that stores personalized or anonymized data, such as blood glucose measurements, past IOB or TDI, prior carbohydrate compensation doses, and other forms of data. Additionally, the cloud-based service 111 can process anonymized information from multiple users to provide generalized information related to TDI, insulin sensitivity, IOB, etc. The communication link 115 coupling the cloud server 112 to other components of the system 100, such as the devices 102, 105, 106, 108 of the system 100, can be a cellular link, a Wi-Fi link, a Bluetooth link, or a combination thereof.

[0042] communication links Wireless communication links 115 and 191-196 may be any type of wireless link operating using a known wireless communication standard or a proprietary standard. By way of example, wireless communication links 191-196 may provide a communication link based on Bluetooth, Zigbee, Wi-Fi, a near field communication standard, a cellular standard, or any other wireless protocol via respective communication interfaces 126, 135, 154, and 174.

[0043] Example of operation In an operational example, the user application 160 implements a graphical user interface that is the primary interface with the user and is used to activate the drug delivery device 102, trigger needle / cannula insertion, start and stop the drug delivery device 102, and program basal and bolus calculator settings for manual mode as well as settings specific to automatic mode (hybrid closed loop or closed loop).

[0044] The user application 160 provides a graphical user interface 158 that allows the use of large text, graphics, and on-screen instructions to prompt the user through the setup process and use of the system 100. It may also be used to program the user's custom basal insulin delivery profile, accept a recommended basal insulin delivery profile, check the status of the medication delivery device 102, initiate an insulin bolus, change the patient's insulin delivery profile, handle system alerts and alarms, or allow the user to switch between automatic and manual modes.

[0045] The user application 160 can be configured to operate in a manual mode in which the user application 160 delivers insulin at a programmed basal rate and a user-defined bolus amount, with the option to set a temporary basal profile. The controller 121 also has the capability to function as a sensor-enhanced pump in manual mode, using sensor glucose data provided by the analyte sensor 108 to feed into a bolus calculator.

[0046] The user application 160 may be configured to operate in an automatic mode that supports the use of one or more target blood glucose levels, which the user application 160 can adjust manually or automatically by the system. For example, in one embodiment, the target blood glucose level may be in the range of 110 mg / dL to 150 mg / dL, in 10 mg / dL increments, 5 mg / dL increments, or other increments, preferably in 10 mg / dL increments. The user experience mirrors the current setup flow, whereby the healthcare provider assists the user in programming the basal rate, glucose target, and bolus calculator setup, which inform the user application 160 of insulin dosing parameters. The insulin dosing parameters are adapted over time based on the total daily insulin (TDI) delivered during each use of the medication delivery device 102. The pseudo-hypoglycemia protection mode or activity mode may be implemented by the user in the automatic mode for various durations. In hypoglycemia protection mode or activity mode, the algorithm reduces insulin delivery and is intended for use for a hypoglycemic duration when insulin sensitivity is expected to be higher, such as during exercise or fasting.

[0047] The user application 160 (or MDA 129) may provide periodic insulin microboluses based on past glucose measurements and / or predicted glucose over a predicted period (e.g., 60 minutes). Optimal post-meal control may require the user to deliver meal boluses in the same manner as current pump therapy, but the normal operation of the user application 160 compensates for missed meal boluses and reduces prolonged hyperglycemia. The user application 160 uses a control-to-target strategy that attempts to achieve and maintain set target blood glucose levels, thereby reducing the duration of prolonged hyperglycemia and hypoglycemia.

[0048] In some embodiments, the user device 105 and the analyte sensor 108 may not communicate directly with each other. Instead, data from the analyte sensor (e.g., blood glucose level) may be transmitted to the medication delivery device 102 via link 196 and then relayed to the user device 105 via link 194. In some embodiments, the serial number of the analyte sensor must be entered into the user application 160 to enable communication between the analyte sensor 108 and the user device 105.

[0049] The user application 160 may provide the ability to calculate a suggested bolus dose through the use of a bolus calculator. The bolus calculator is provided as a user convenience to help determine a suggested bolus dose based on ingested carbohydrates, the most recent blood glucose reading (or blood glucose reading if using a fingertip), a programmable correction factor, an insulin to carbohydrate ratio, a target blood glucose level, and on-board insulin (IOB). The user application 160 estimates the IOB, taking into account the manual bolus and insulin.

[0050] In a first aspect of the present invention, the inner reservoir 202 is held stationary relative to the housing of the drug delivery device 102 during the filling process, while the outer reservoir 204 is free to move during the filling process. This is shown in FIG. 2(a). Various mechanisms can be used to hold the inner reservoir 202 stationary during the filling process. In the embodiment shown in FIG. 2(a), a lead screw 208 holds the inner reservoir 202 stationary during the filling process. A clutch mechanism (not shown) decouples the outer reservoir 204 from the housing of the drug delivery device 102, allowing the outer reservoir 204 to move linearly, motivated (i.e., driven) by the pressure of the liquid drug as it enters the reservoirs 202, 204. After the filling process is complete, the clutch mechanism engages the outer reservoir 204, thereby making it fixed relative to the housing of the drug delivery device 102, and allows the drive mechanism to move the inner reservoir 202 to pump the liquid drug. This is shown in Figure 2(b). The various embodiments of the clutch mechanism described and illustrated herein are directed to this aspect of the invention. It will be understood that in various embodiments, either the outer reservoir or the inner reservoir can move relative to the other fixed reservoir.

[0051] 3(a)-3(b) show a first embodiment of the first aspect of the present invention. In this embodiment, the external reservoir 204 is provided with a brake mechanism comprising a lever 302 and a brake pad 304. Before and during the filling process shown in FIG. 3(a), the brake mechanism is disengaged, allowing the external reservoir 204 (or the internal reservoir 202) to move freely while the internal reservoir 202 (or the external reservoir 204) is held stationary by a drive mechanism (not shown in this figure). After the filling process is completed, the brake mechanism is engaged by moving the lever 302 in direction "A" to pivot the lever 302 about pivot point 308, as shown in FIG. 3(b). This pivoting action brings the brake pad 304 into contact with the outer surface of the external reservoir 204, thereby securing it to the housing of the medication delivery device 102. During pumping of the liquid drug, the inner reservoir 202 is driven by the drive mechanism to move in direction "B" relative to the outer reservoir 204 to cause pumping of the liquid drug.

[0052] In a second embodiment, as shown in FIG. 4(a), the outer reservoir 204 is constructed of (or comprises) a first sheet of hook and loop fasteners 404 or other fastener material that can be adhered to the outer surface of the outer reservoir 204. A second mating sheet of hook and loop fasteners 402 is adhesively attached to the housing of the drug delivery device 102. During the filling process, a sheath (not shown) is placed between the hook and loop fastener sheets 402, 404 to prevent engagement between the sheets 402 and 404, thereby allowing the outer reservoir 204 to move relative to the housing of the drug delivery device 102. The inner reservoir 202 (not shown in FIG. 4(a)) is held fixed by a drive mechanism. After the filling process is completed, the sheath is removed and the hook and loop fastener sheets 402, 404 engage with each other, preventing further movement of the outer reservoir 204. During the pumping process, the inner reservoir 202 is driven by a drive mechanism to move relative to the fixed outer reservoir 204. The sheath disposed between the hook and loop fastener sheets 402 and 404 can be removed by any known mechanism.

[0053] A variation of this embodiment may use a two-part adhesive that activates when the two parts come into contact with each other, as shown in FIG. 4(b). A first part 406a of the adhesive is coupled to the reservoir 202, and a second part 406b is coupled to the housing of the drug delivery device 102. During the filling process, a liner 408 prevents contact between the adhesive parts 406a and 406b. After the filling process is complete, the liner 408 is pulled from between the parts 406a, 406b to activate the adhesive, allowing the parts 406a, 406b to touch each other and holding the outer reservoir 204 in a fixed position relative to the housing of the drug delivery device 102. The liner 408 can be pulled from between the adhesive parts 406a, 406b by any known means.

[0054] In a third embodiment, as shown in FIG. 5 , the outer reservoir 204 is configured with a clamp 502 that is directly or indirectly coupled to the housing of the drug delivery device 102. In some embodiments, the clamp 502 is annular, more specifically, an open annular ring with at least one arm, particularly at least one linear arm, at each end. During the filling process, the clamp 502 is tensioned by moving the clamp arms in the direction opposite to that indicated by the arrows in FIG. 5 , disengaging the clamp 502 from the outer reservoir 204 and allowing the outer reservoir 204 to move linearly relative to the inner reservoir 202. In some embodiments, during filling, the clamp arms are moved opposite to each other such that the inner diameter of the clamp 502 increases, particularly so that the arms overlap and the ends of the arms approach each other. The inner reservoir 202 is held stationary by a drive mechanism. After the filling process is complete, the clamp 502 is tightened around the outer periphery of the outer reservoir 204 by releasing the tension on the clamp 502, causing the arms of the clamp 502 to move in the direction of the arrows in Figure 5. In some embodiments, after filling, the arms of the clamp move opposite each other so that the inner diameter of the clamp 502 decreases, particularly so that the arms overlap and the ends of the arms move away from each other. Thus, the clamp 502 engages the outer reservoir 204, fixing it to the housing of the drug delivery device 102. During the pumping process, the inner reservoir 202 is driven by a drive mechanism to move relative to the now-fixed outer reservoir 204. The clamp 502 can be moved to the tensioned state by any known mechanism or trigger.

[0055] 6(a)-6(b) show two separate embodiments using a guy rope 602. In the first embodiment shown in FIG. 6(a), the guy rope 602 is coupled to the housing of the drug delivery device 102 at points 606a and 606b (e.g., coupled to the housing of the drug delivery device 102 at a first point connected to the housing (e.g., 606a) and a second point connected to the housing (e.g., 606b)), and the external reservoir 204 is configured to move linearly between the first point 606a and the second point 606b). The guy rope 602 is further connected to the outer reservoir 204 at connection points 608 (e.g., connected to the outer reservoir 204 at a third point 608a and a fourth point 608b, the fourth point 608b being located closer to the second point 606b than the third point 608a; in particular, the third point 608a and the fourth point 608b are offset relative to each other in a direction perpendicular to the linear movement direction of the outer reservoir 204). The guy rope 602 can pivot (i.e., move) around the connection points 606a, 606b, 608a, and 608b. During the filling process, slack in the guy rope 602 allows the outer reservoir 204 to move relative to the inner reservoir 202 (not shown in this example). Upon completion of the filling process, the spring 604 is released, tensioning the guy line 602 and preventing further movement of the outer reservoir 204 relative to the housing of the medication delivery device 102 .

[0056] 6(b) shows a second embodiment using a guy line 610. In this embodiment, the guy line 610 is rigidly connected to the external reservoir 204 at a connection point 612 and is free to move around a pivot point 614. The connection point 612 and / or the pivot point 614 may be connected to the external reservoir 204. During the filling process, the guy line 610 is pulled in direction "C" by the movement of the reservoir in direction "C". During the filling process, the spring 616 is tensioned to allow free movement of the guy line 610 through a hole defined in the spring 616. After the filling process is completed, the tension in the spring 616 is released, thereby preventing further movement of the guy line 610 to secure the external reservoir 204 relative to the housing of the drug delivery device 102. In particular, the through holes defined in the spring 616 may align when the spring 616 is under tension and may not align when the tension on the spring 616 is released. The ends of the guy lines 610 may be retracted by any known means and may be paid out when the outer reservoir 204 is moved in direction "C".

[0057] 7(a)-7(b) show two embodiments using a bistable mechanism to hold the external reservoir 204 in place after the filling process is complete. FIG. 7(a) shows a first bistable mechanism 702 coupled to the housing of the drug delivery device 102. During the filling process, the arms of the bistable mechanism 702 pivot on a pivot point 704 to a first stable position, disengaging the arms of the bistable mechanism 702 from the external reservoir 204. After the filling process, the bistable mechanism 702 moves to a second stable state, in which the arms of the mechanism engage a portion of the outer surface of the external reservoir 204 to prevent further movement of the external reservoir 204. The transition of the bistable mechanism 702 from the first stable state to the second stable state can be initiated by a trigger mechanism of any design.

[0058] FIG. 7(b) shows several bistable mechanisms 706 of different designs. The term "bistable mechanism" used may refer to a mechanism having two (mechanically) stable geometric configurations, i.e., one geometric configuration requires a greater force to change compared to the other geometric configuration. The bistable mechanism 706 is coupled to the housing of the drug delivery device 102 and, in a first stable state, is disengaged from the external reservoir 204. After the filling process, the mechanism 706 moves to a second stable state in which the mechanism 706 engages with the outer surface of the external reservoir 204 to prevent further movement of the external reservoir 204. The transition of the bistable mechanism 706 from the first stable state to the second stable state may be initiated by a trigger mechanism of any design. In some embodiments, the bistable mechanism 706 comprises one or more legs and a body, wherein the one or more legs move toward the external reservoir 204, particularly until they engage with the external reservoir, when transitioning from the first stable state to the second stable state, and the one or more legs move away from the external reservoir 204, particularly until they disengage from the external reservoir 204. In some embodiments, the bistable mechanism 706 comprises multiple legs, particularly three or four legs, arranged around its body. In some embodiments, the one or more legs bend relative to the body when transitioning from the first stable state to the second stable state and vice versa. In some embodiments, one or more bistable mechanisms 706 are coupled to the housing of the drug delivery device 102, more particularly, two to four bistable mechanisms 706 are coupled to the housing of the drug delivery device 102, particularly three bistable mechanisms are coupled to the housing of the drug delivery device 102. In some embodiments, the bistable mechanism 706 is coupled to the external reservoir 204, and one or more legs move toward the housing of the drug delivery device 102 until they engage with the housing of the drug delivery device 102, particularly when transitioning from a first stable state to a second stable state, and one or more legs move away from the housing of the drug delivery device 102 until they are disengaged from the housing of the drug delivery device 102.

[0059] In a second aspect of the invention, the outer reservoir 204 is held stationary relative to the housing of the drug delivery device 102 during the filling process, while the inner reservoir 202 is free to move during the filling process. In these embodiments, the outer reservoir 204 is typically coupled in some way to the housing of the drug delivery device 102. The inner reservoir 202 is decoupled from the drive mechanism by a clutch mechanism and is free to move, driven by the pressure of the liquid drug, once the reservoirs 202, 204 are filled. After filling, the clutch mechanism re-engages the inner reservoir 202 with the drive mechanism.

[0060] One embodiment of the second aspect of the present invention is shown in Figure 8. In this embodiment, the drive mechanism consists of a tube nut 206 that is rotated to drive a lead screw 208, which is rigidly coupled to the inner reservoir 202. Figure 8(a) shows the state of the mechanism before filling, in this embodiment, a clutch 802 comprising a torsion spring is tensioned and disengaged from the lead screw 208, thereby allowing the lead screw 208 to move freely within the tube nut 206. In this state, the lead screw 208 is positioned within the tube nut 206. As the reservoirs 202, 204 are filled, the inner reservoir 202 moves in direction "D," pulling the lead screw 208 from its previous position within the tube nut 206 during this filling process. Figure 8(b) shows the pump mechanism in a filling state. Once the reservoirs 202, 204 are filled, the clutch mechanism 802 is released from tension, forcing the end of the tube nut 206 closer to the lead screw 208 by the constriction of the end of the tube nut 206 and the slit 804 defined in the end of the tube nut 206, and threading the tube nut 206 onto the lead screw 208. Thereafter, rotation of the tube nut 206 causes the inner reservoir 202 to move in a direction opposite to the direction "D" for pumping the liquid medicament due to the threaded engagement between the tube nut 206 and the lead screw 208.

[0061] 9(a)-9(b) show a variation of the embodiment of FIG. 8 that utilizes a different clutch mechanism. Similar to the embodiment of FIG. 8, during the filling process shown in FIG. 9(a), the lead screw 208 is free to move within the tube nut 206 due to the widening of several slits 906 defined in the end of the tube nut 206. Once the filling process is complete, as shown in FIG. 9(b), tension in the spring 904 is released, thereby pushing the collet 902 to the end of the tube nut 206, constricting the end of the tube nut 206 due to the narrowing of the slits 906 and forcing the tube nut 206 into a threaded engagement with the lead screw 208, connecting it to the outer reservoir 204. Rotation of the tube nut 206 will cause linear movement of the inner reservoir 202, pumping the liquid medicament. The spring 904, as shown in FIG. 9(a), can be held in its tensioned state by any known means and released by a trigger mechanism of any design.

[0062] FIGS. 10(a)-10(c) illustrate yet another embodiment of a clutch mechanism. In this embodiment, the lead screw 208 has a portion 1002 defined on one end thereof that has an elliptical cross-sectional shape, as shown in FIG. 10(a). In addition, the inner diameter of the tube nut 206 also has a cross-sectional shape. When the major axis of the elliptical portion 1002 of the lead screw 208 is aligned with the major axis of the inner diameter of the tube nut 206, as shown in FIG. 10(b), the lead screw 208 is free to move within the tube nut 206. During the filling process, the lead screw 208 moves in direction "E." Once the filling process is complete, the tube nut 206 is rotated, for example, 90°, so that the major axis of the portion 1002 of the lead screw 208 is aligned with the minor axis of the elliptical cross-section of the inner diameter of the tube nut 206, thereby creating a friction lock between the tube nut 206 and the lead screw 208, as shown in FIG. 10(c). In this embodiment, the lead screw 208 is in threaded engagement with the inner reservoir 202. Rotation of the tube nut 206, and by virtue of the threaded engagement between the lead screw 208 and the inner reservoir 202, causes rotation of the lead screw 208, driving the inner reservoir 202 to move in the opposite direction "E."

[0063] FIG. 11 illustrates yet another embodiment in which the tube nut 206 can be positioned to allow the lead screw 208 to move freely within the tube nut 206. In this configuration, the lead screw 208 is configured with several notched regions 1102 extending along the longitudinal axis of the lead screw 208. The inner diameter of the tube nut 206 is configured to have unthreaded regions. When the unthreaded regions on the inner diameter of the tube nut 206 align with the notched regions 1002 on the lead screw 208, as shown in FIG. 11, the lead screw 208 is free to move within the tube nut 206. During the filling process, these (unthreaded) regions align, allowing linear movement of the inner reservoir 202, driven by the pressure of the liquid agent as the reservoirs 202, 204 fill. Then, during the pumping process, the tube nut 206 can be rotated, creating a threaded engagement with the lead screw 208 and driving the inner reservoir to pump the liquid agent. One thread side of the lead screw 208 may be larger than the other thread side of the lead screw 208 to help at least one portion of the lead screw 208 engage with corresponding threads on the tube nut 206 during the pumping process. Additionally or alternatively, as the lead screw 208 (or alternatively, the tube nut 206) rotates during the pumping process, the threads of the tube nut 206 and the threads of the lead screw 208 may only engage with portions of each other at that time. The pump drive algorithm may take this into account (i.e., some of the time, the lead screw (or tube nut) does not rotate as the tube nut (or lead screw) rotates) and adjust the drug delivery or advancement of the delivery mechanism accordingly.

[0064] 12(a)-12(b) illustrate an embodiment in which the internal reservoir 202 is configured with a clamp 1202 that engages with the lead screw 208. During the filling process shown in FIG. 12(a), the clamp 1202 is released from engagement with the lead screw 208, allowing the internal reservoir 202 to move freely in direction "F" driven by the pressure of the liquid agent, filling the reservoirs 202, 204. Once the filling process is complete, as shown in FIG. 12(b), the clamp 1202 engages the lead screw 208 such that rotation of the tube nut 206 that threads with the lead screw 208 drives linear movement of the internal reservoir 202 in the reverse direction "F" to pump the liquid agent. The clamp 1202 can be engaged and disengaged from the lead screw 208 by any known means, such as via a spring that disengages the clamp 1202 from the lead screw 208 when tension is applied and urges the clamp 1202 into engagement with the lead screw 208 when tension is not applied.

[0065] 13(a)-13(b) show a variation of the embodiment of FIG. 12. In this embodiment, upon completion of the filling process shown in FIG. 13(b), the wedge 1304 is driven by tension released in the spring 1306 to engage the portion 1302 of the internal reservoir 202. The wedge 1304 may be configured with a slit such that engagement of the wedge 1304 with the portion 1302 of the internal reservoir 202 narrows the slit (not visible) in the wedge 1304, thereby clamping the wedge 1304 to the lead screw 208. During the pumping process, rotation of the tube nut 206 causes linear movement of the internal reservoir 202, which is coupled to the lead screw 208 by the wedge 1304. The pre-fill condition is shown in Figure 13(a) where wedge 1304 is held back from section 1302 and spring 1306 is under tension. Wedge 1304 is held before and during the filling process by any known means, and the tension on spring 1306 is released via a trigger mechanism of any design.

[0066] 14(a)-14(c) show yet another variation of the clamping mechanism. In this embodiment, the internal reservoir 202 includes a metal band 1402 that is tensioned by being held in an open position in the pre-filled state shown in FIG. 14(a). After the filling process is complete, the tension on the metal band 1402 is released, causing the hinge 1404 to close around the lead screw 208, thereby coupling the internal reservoir 202 to the lead screw 208, as shown in FIG. 14(b). In certain embodiments, a portion of the lead screw 208 may have a corrugated cross-sectional shape, as shown in FIG. 14(c), to promote frictional engagement with the inner surface of the hinge 1404. Additionally, the inner surface of the hinge 1404 may be configured with a rubber pad 1406 to further assist in the frictional coupling between the hinge 1404 and the lead screw 208. Before and during the filling process, the metal bands 1402 may be held open by any known means, and then the hinges 1404 may be triggered to close by a trigger mechanism of any design.

[0067] 15 shows another embodiment utilizing a clamp 1502 to couple the lead screw 208 to the internal reservoir 202. In this embodiment, the clamp 1502 comprises a torsion spring. During the filling process, the spring 1502 is held in an open, tensioned position by movement of end 1502b. End 1502a is coupled to the internal reservoir 202. After the filling process is complete, movement of end 1502b releases the tension in the spring 1502, engaging the spring with the lead screw 208 and coupling the lead screw 208 to the internal reservoir 202. End 1502b of the spring 1502 can be manipulated by any known means and can be triggered by a trigger mechanism of any design.

[0068] 16(a)-16(c) illustrate another embodiment utilizing a clamp 1602. In this embodiment, as the reservoirs 202, 204 fill, the clamp 1602, which is coupled to the inner reservoir 202, is free to move on the outer surface of the tube nut 206 as the inner reservoir 202 moves linearly away from the outer reservoir 204. As shown in FIG. 16(c), a spring 1604 wrapped around the lead screw 208 is tensioned by pushing a hook on the end of the spring 1604 in the opposite direction. Once the filling process is complete, the tension on the spring 1604 is released, and the hook engages the clamp 1602, engaging the clamp 1602 with the tube nut 206, thereby preventing further movement of the tube nut 206 relative to the clamp 1602 and coupling the tube nut 206 to the inner reservoir 202. The spring 1604 may be held in tension by any known means and released by a trigger mechanism of any design.

[0069] 17(a)-17(b) show a variation of the embodiment shown in FIGS. 16(a)-16(c) that utilizes a spring 1704 engaging a rod 1706 to urge a clamp 1702 into engagement with a tube nut 206. During the filling process, the spring 1704 is tensioned to relieve pressure on the rod 1706, allowing the clamp 1702 to translate linearly on the tube nut 206 as the reservoir 202 translates linearly away from the reservoir 204. After the filling process is complete, the tension on the spring 1704 is released, forcing the rod 1706 against the clamp 1702 and engaging the clamp 1702 with the tube nut 206, thereby coupling the reservoir 202 to the tube nut 206. The spring 1704 may be held in tension by any known means and released by a trigger mechanism of any design.

[0070] 18(a)-18(c) illustrate an embodiment in which the internal reservoir 202 is coupled to a rod 1802 and can move linearly through a clamp 1804 coupled to the tube nut 206 before and during the filling process shown in FIG. 18(a). The clamp 1804 shown in FIG. 18(c) is held in tension by moving its arms toward each other, disengaging its arms from the rod 1802 and allowing the rod 1802 to move linearly through a hole defined in the arms of the clamp 1804. After the filling process is complete, as shown in FIG. 18(b), the tension on the arms of the clamp 1804 is released, causing the arms to engage the rod 1802 and prevent further movement of the rod 1802 through the hole defined in the arms of the clamp 1804, thereby coupling the internal reservoir 202 to the tube nut 206. The arms of clamp 1804 may be held together to tension clamp 1804 by any known means and may be released by a trigger mechanism of any design.

[0071] 19(a)-19(b) show a variation of the embodiment of FIGS. 18(a)-18(c) in which tube nut 206 is coupled to rod 1802 by a collet mechanism. The collet mechanism includes a spring 1906, a spring plate 1904, and a collet 1902. During the filling process, as shown in FIG. 19(b), spring 1906 is tensioned and collet 1902 is decoupled from rod 1802. After the filling process is complete, the tension in spring 1906 is released, thereby forcing collet 1902 through a hole defined in tube nut 206. This compresses the arms of collet 1902 around rod 1804, thereby coupling tube nut 206 to rod 1802. Rod 1802 is coupled to inner reservoir 202 as shown in Figure 18(b) so that when collet 1902 engages rod 1802, inner reservoir 202 becomes coupled to tube nut 206. Spring 1906 may be held in tension by any known means and may be released by a trigger mechanism of any design.

[0072] 20(a)-20(b) show another embodiment utilizing a two-body torsion spring 2004 as a clamp. The internal reservoir 202 includes a rod 2002 engaged by one body of the two-body torsion spring 2004. The other body of the two-body torsion spring 1204 engages the tube nut 206. During the filling process, the two-body torsion spring 2004 is tensioned, thereby allowing the rod 2002 to move linearly through the spring 2004. After the filling process is complete, the tension on the spring 2004 is released, causing it to clamp to both the rod 2002 and the tube nut 206, connecting the tube nut 206 to the internal reservoir 202. The spring 2004 can be held in tension by any known means and can be released by a trigger mechanism of any design.

[0073] As will be recognized by those skilled in the art, many variations of the embodiments disclosed herein are possible. In particular, various dimensions, materials, and configurations are contemplated as being within the scope of the present invention, and the present invention is not meant to be limited by the specific embodiments disclosed herein. In addition, the described embodiments are not mutually exclusive and may be used in conjunction with one another.

[0074] The following examples relate to various embodiments disclosed herein of needle insertion / retraction mechanisms for use with automated drug delivery systems.

[0075] Example 1 is a first embodiment of a pump mechanism for a drug delivery device, the pump mechanism comprising an outer reservoir, an inner reservoir configured to move linearly into the outer reservoir, a drive mechanism for moving the inner reservoir linearly into the outer reservoir, and a clutch mechanism for connecting the outer reservoir or the inner reservoir to a housing of a drug delivery device.

[0076] Example 2 is within the scope of Example 1 or any other example disclosed herein, wherein the clutch mechanism includes a brake pad and a lever for forcibly engaging the brake pad with the outer surface of the outer reservoir.

[0077] Example 3 is within the scope of Example 1 or any other example disclosed herein, wherein the clutch mechanism comprises a first piece of Velcro® attached to the housing of the medication delivery device, a second piece of mating Velcro® attached to the outer surface of the external reservoir, and a sheath disposed between the first piece of Velcro® and the second piece of Velcro® to prevent engagement of the first piece of Velcro® and the second piece of Velcro®, the sheath being removed after filling of the pump mechanism to disengage the first piece of mating Velcro® and the second piece of mating Velcro® to prevent further movement of the external reservoir.

[0078] Example 4 is within the scope of Example 1 or any other example disclosed herein, wherein the clutch mechanism comprises a first adhesive pad attached to the housing of the medication delivery device, a second adhesive pad attached to the outer surface of the outer reservoir, and a liner disposed between the first and second adhesive pads, the liner being removed after filling the pump mechanism, and further wherein adhesives on the first and second adhesive pads are activated when the first and second adhesive pads contact each other.

[0079] Example 5 is within the scope of Example 1 or any other example disclosed herein, wherein the clutch mechanism comprises a spring clamp attached to the housing of the drug delivery device and positioned around the outer surface of the outer reservoir, which, when tensioned, allows linear movement of the outer reservoir and, when untensioned, engages with the outer reservoir to prevent further movement of the outer reservoir.

[0080] Example 6 is within the scope of Example 1 or any other example disclosed herein, wherein the clutch mechanism comprises a guy line attached to the housing of the drug delivery device and the external reservoir, the guy line causing the external reservoir to move along the guy line as the pump mechanism fills, and a spring mechanism applying tension to the guy line when no tension is applied to prevent further movement of the external reservoir.

[0081] Example 7 is within the scope of Example 1 or any other example disclosed herein, wherein the clutch mechanism comprises a guy line attached to the housing of the drug delivery device and the external reservoir, such that the external reservoir pulls along the guy line as the pump mechanism fills, and a clamping mechanism that clamps the guy line to prevent further movement of the external reservoir when tension is not applied.

[0082] Example 8 is within the scope of Example 1 or any other example disclosed herein, wherein the clutch mechanism comprises one or more bistable mechanisms rigidly attached to the housing of the drug delivery device, the one or more bistable mechanisms disengaging from the outer reservoir in a first stable state to allow linear movement of the outer reservoir, and engaging with the outer reservoir in a second stable state to prevent further movement of the outer reservoir.

[0083] Example 9 is a second embodiment of a pump mechanism for a drug delivery device, the pump mechanism comprising an outer reservoir, an inner reservoir configured to move linearly into the outer reservoir, a drive mechanism for moving the inner reservoir linearly into the outer reservoir, and a clutch mechanism for connecting the inner reservoir to the drive mechanism.

[0084] Example 10 is within the scope of example 9 or any other example disclosed herein, wherein the drive mechanism comprises a tube nut and a lead screw.

[0085] Example 11 is within the scope of Example 10 or any other example disclosed herein, wherein the clutch mechanism comprises a torsion spring disposed around an outer surface of the tube nut, which, when tensioned, allows the lead screw to move linearly through the tube nut and, when untensioned, forces the tube nut into threaded engagement with the lead screw, the lead screw being coupled to the internal reservoir.

[0086] Example 12 is within the scope of Example 10 or any other example disclosed herein, wherein the clutch mechanism includes a spring disposed around the tube nut and a collet disposed around the tube nut, the spring translating the collet when not under tension, the collet translating to force the tube nut into threaded engagement with the lead screw, and the lead screw is coupled to the internal reservoir.

[0087] Example 13 is a scope of Example 10, or any other example disclosed herein, wherein at least a portion of the lead screw has an elliptical cross-sectional shape, the inner diameter of the tube nut has an elliptical cross-sectional shape, during the filling process, a major axis of the elliptical portion of the lead screw is aligned with a major axis of the inner diameter of the tube nut, and after the filling process, the tube nut is rotated such that the major axis of the elliptical portion of the lead screw is aligned with a minor axis of the inner diameter of the tube nut, creating frictional engagement between the lead screw and the tube nut, and the lead screw threadably engages with the internal reservoir.

[0088] Example 14 is within the scope of Example 10 or any other example disclosed herein, wherein the lead screw has one or more non-threaded notch portions along its longitudinal length, the inner diameter of the tube nut has one or more non-threaded portions corresponding to the one or more non-threaded notch portions of the lead screw, and after a filling process, rotation of the tube nut forms a threaded engagement with the lead screw, and the lead screw is connected to the internal reservoir.

[0089] Example 15 is a range of example 10, or any other example defined herein, wherein the clutch mechanism comprises a clamp coupled to the inner reservoir and a mechanism for engaging the clamp with the lead screw.

[0090] Example 16 is within the scope of Example 10 or any other example disclosed herein, wherein the clutch mechanism includes a spring disposed around the lead screw and a wedge disposed around the lead screw, and when the spring is not tensioned, the spring presses the wedge into a portion of an internal reservoir configured to receive the wedge, engaging the wedge with the lead screw.

[0091] Example 17 is within the scope of Example 10 or any other example disclosed herein, wherein the clutch mechanism includes a spring disposed around an outer surface of the inner reservoir and a clamp, the spring engaging the clamp with the lead screw when not tensioned.

[0092] Example 18 is the scope of example 17 or any other example disclosed herein, wherein the clamp is configured with a rubber insert to provide frictional engagement with the lead screw.

[0093] Example 19 is the scope of example 17 or any other example disclosed herein, wherein the lead screw is configured with a corrugated portion at one end to provide frictional engagement with the clamp.

[0094] Example 20 is within the scope of Example 10 or any other example disclosed herein, wherein the clutch mechanism includes a torsion spring coupled at one end to the internal reservoir and disposed around the lead screw, wherein the torsion spring, when tensioned, allows linear movement of the lead screw and, when untensioned, engages the lead screw to prevent further linear movement of the lead screw.

[0095] Example 21 is within the scope of Example 10 or any other example disclosed herein, wherein the clutch mechanism includes a clamp coupled to the inner reservoir and positioned around the outer periphery of the tube nut, and a spring connected between two ends of the clamp, wherein the spring, when tensioned, allows the tube nut to move linearly through the clamp and, when untensioned, forcibly engages the clamp with the tube nut to prevent further linear movement of the tube nut through the clamp.

[0096] Example 22 is within the scope of Example 10 or any other example disclosed herein, wherein the clutch mechanism includes a rod connected to the inner reservoir and a clamp connected to the tube nut, the clamp allowing linear movement of the rod when tensioned and preventing linear movement of the rod when untensioned.

[0097] Example 23 is within the scope of Example 10 or any other example disclosed herein, wherein the clamp includes a spring and a collet, and when the spring is not tensioned, the spring forces the collet to engage the rod through a hole defined in the tube nut to prevent linear movement of the rod.

[0098] Example 24 is within the scope of Example 10 or any other example disclosed herein, wherein the clutch mechanism includes a rod connected to the inner reservoir and a two-body torsion spring, one body of the torsion spring disposed around the rod and another body of the torsion spring disposed around a tube nut, the torsion spring allowing linear movement of the rod when tensioned and preventing linear movement of the rod when untensioned.

[0099] Software-related implementations of the techniques described herein may include, but are not limited to, firmware, application-specific software, or any other type of computer-readable instructions that may be executed by one or more processors. The computer-readable instructions may be provided via a non-transitory computer-readable medium. Hardware-related implementations of the techniques described herein include, but are not limited to, integrated circuits (ICs), application-specific ICs (ASICs), field programmable arrays (FPGAs), and / or programmable logic devices (PLDs). In some embodiments, the techniques described herein and / or any systems or components described herein may be implemented with a processor that executes computer-readable instructions stored on one or more memory components.

[0100] Those skilled in the art to which the present invention pertains will recognize many modifications and adaptations of the present invention. The embodiments provided herein, including the dimensions, shapes, ratings, and specifications of various components or component arrangements, as well as descriptions of specific manufacturing processes, are illustrative only and are not intended to limit the present invention in any way. As those skilled in the art will appreciate, many variations of the configurations discussed herein are possible that fall within the scope of the present invention. Furthermore, it should be understood that the features of the various aspects described herein are not mutually exclusive and can exist in various combinations and permutations without departing from the spirit and scope of the present invention, even if such combinations or permutations are not expressly stated herein. Accordingly, the methods and apparatus disclosed herein should be construed as illustrative, not limiting, of the present invention. The scope of the present invention is defined by the following claims.

Claims

1. 1. A pump mechanism for a drug delivery device, comprising: The pump mechanism includes: an outer reservoir; and an inner reservoir configured for linear movement into the outer reservoir; a drive mechanism for linearly moving the inner reservoir into the outer reservoir; a clutch mechanism for connecting the outer reservoir or the inner reservoir to a housing of a medication delivery device.

2. The clutch mechanism includes: Brake pads and 2. The pump mechanism of claim 1, further comprising a lever for forcing the brake pads into engagement with an outer surface of the outer reservoir.

3. The clutch mechanism includes: a first piece of hook and loop fastener attached to the housing of the medication delivery device; a second piece of mating hook and loop fastener attached to the exterior surface of the outer reservoir; a sheath disposed between the hook and loop fastener of the first piece and the hook and loop fastener of the second piece to prevent engagement of the hook and loop fastener of the first piece with the hook and loop fastener of the second piece; 2. The pump mechanism of claim 1, wherein the sheath is removed after filling the pump mechanism to allow engagement of the hook and loop fasteners of the first piece with the hook and loop fasteners of the second piece to prevent further movement of the outer reservoir.

4. The clutch mechanism includes: a first adhesive pad attached to a housing of the medication delivery device; a second adhesive pad attached to the outer surface of the outer reservoir; a liner disposed between the first and second adhesive pads; the liner is removed after filling the pump mechanism; 10. The pump mechanism of claim 1, further comprising: when the first adhesive pad and the second adhesive pad contact each other, adhesive on the first adhesive pad and the second adhesive pad is activated.

5. The clutch mechanism includes: a spring clamp attached to the housing of the medication delivery device and disposed around an outer surface of the external reservoir; 2. The pump mechanism of claim 1, wherein the spring clamp, when in a tensioned state, allows linear movement of the outer reservoir and, when in an untensioned state, engages the outer reservoir to prevent further movement of the outer reservoir.

6. The clutch mechanism includes: a guy line attached to the housing of the medication delivery device and the external reservoir, the external reservoir moving along the guy line as the pump mechanism fills; 2. The pump mechanism of claim 1, further comprising a spring mechanism that tensions the guy line when untensioned to prevent further movement of the outer reservoir.

7. The clutch mechanism includes: a guy line attached to the housing of the medication delivery device and the external reservoir, the external reservoir pulling along the guy line as the pump mechanism fills; 10. The pump mechanism of claim 1, further comprising a clamping mechanism that clamps the guy line to prevent further movement of the outer reservoir when no tension is applied.

8. The clutch mechanism includes:

2. The pump mechanism of claim 1, comprising one or more bistable mechanisms rigidly attached to a housing of the drug delivery device, the one or more bistable mechanisms disengaging from the outer reservoir in a first stable state to allow linear movement of the outer reservoir, and engaging with the outer reservoir in a second stable state to prevent further movement of the outer reservoir.

9. 1. A pump mechanism for a drug delivery device, comprising: The pump mechanism includes: an outer reservoir; and an inner reservoir configured for linear movement into the outer reservoir; a drive mechanism for linearly moving the inner reservoir into the outer reservoir; a clutch mechanism for coupling the internal reservoir to the drive mechanism.

10. The drive mechanism includes: Tube nuts and A pump mechanism as claimed in claim 9, comprising a lead screw.

11. The clutch mechanism includes: a torsion spring disposed about an outer surface of the tube nut, the torsion spring, when tensioned, allowing the lead screw to move linearly through the tube nut and, when untensioned, forcing the tube nut into threaded engagement with the lead screw; The pump mechanism of claim 10 , wherein the lead screw is coupled to the internal reservoir.

12. The clutch mechanism includes: a spring disposed around the tube nut; a collet disposed around the tube nut; When the spring is not tensioned, it causes the collet to move linearly, and the linear movement of the collet forces the tube nut into threaded engagement with the lead screw; The pump mechanism of claim 10 , wherein the lead screw is coupled to the internal reservoir.

13. At least a portion of the lead screw has an elliptical cross-sectional shape; The inner diameter of the tube nut has an oval cross-sectional shape, 11. The pump mechanism of claim 10, wherein during a filling process, a major axis of the elliptical portion of the lead screw is aligned with a major axis of the inner diameter of the tube nut, and after the filling process, the tube nut is rotated so that the major axis of the elliptical portion of the lead screw is aligned with a minor axis of the inner diameter of the tube nut, creating frictional engagement between the lead screw and the tube nut, and the lead screw threadably engages with the internal reservoir.

14. the lead screw having one or more non-threaded notched portions along its longitudinal length; an inner diameter of the tube nut having one or more non-threaded portions corresponding to the one or more non-threaded notch portions of the lead screw; 11. The pump mechanism of claim 10, wherein after a filling process, rotation of the tube nut forms a threaded engagement with the lead screw, connecting the lead screw to the internal reservoir.

15. The clutch mechanism includes: a clamp coupled to the internal reservoir; 11. The pump mechanism of claim 10, further comprising: a mechanism for engaging the clamp with the lead screw.

16. The clutch mechanism includes: a spring disposed around the lead screw; a wedge portion disposed around the lead screw; 11. The pump mechanism of claim 10, wherein when the spring is not tensioned, it compresses the wedge portion into a portion of an internal reservoir configured to receive the wedge portion, engaging the wedge portion with the lead screw.

17. The clutch mechanism includes: a spring disposed around an outer surface of the inner reservoir; a clamp; 16. A pump mechanism as claimed in claim 10 or 15, wherein the spring, when not tensioned, engages the clamp with the lead screw.

18. 18. A pump mechanism according to claim 15 or 17, wherein the clamp is configured with a rubber insert to provide frictional engagement with the lead screw.

19. 19. A pump mechanism according to claim 15, 17 or 18, wherein the lead screw is configured with a corrugated portion at one end thereof to provide frictional engagement with the clamp.

20. The clutch mechanism includes: a torsion spring coupled at one end to the internal reservoir and disposed around the lead screw; 11. The pump mechanism of claim 10, wherein the torsion spring, when in a tensioned state, allows linear movement of the lead screw and, when in an untensioned state, engages the lead screw to prevent further linear movement of the lead screw.

21. The clutch mechanism includes: a clamp connected to the inner reservoir and disposed around the tube nut; a spring connected between the two ends of the clamp; 20. A pump mechanism as claimed in claim 10, 15, 18 or 19, wherein the spring, when tensioned, allows the tube nut to move linearly through the clamp and, when untensioned, forces the clamp to engage the tube nut to prevent further linear movement of the tube nut through the clamp.

22. The clutch mechanism includes: a rod connected to the internal reservoir; a clamp connected to the tube nut; 11. The pump mechanism of claim 10, wherein the clamp allows linear movement of the rod when tensioned and prevents linear movement of the rod when untensioned.

23. The clamp is Springs and a collet; 23. The pump mechanism of claim 22, wherein the spring, when not tensioned, urges the collet through a hole defined in the tube nut into engagement with the rod to prevent linear movement of the rod.

24. The clutch mechanism includes: a rod connected to the internal reservoir; a two-body torsion spring, with one body of the torsion spring disposed around the rod and another body of the torsion spring disposed around a tube nut; 11. The pump mechanism of claim 10, wherein the torsion spring allows linear movement of the rod when in a tensioned state and prevents linear movement of the rod when in an untensioned state.

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