Medication delivery device with syringe sensing system

Abstract

To provide a medication delivery device including a drive mechanism, a retraction mechanism and a sensing system.SOLUTION: A medication container is movable relative to a medication delivery device between storage and delivery positions. A drive mechanism drives a plunger in a translational movement to move the medication container from the storage position to the delivery position and to dispense medication from the medication container in a dispensing event. A retraction mechanism includes a rotary member 70 that rotates during a retraction movement of the retracting mechanism. A sensing system includes a first sensor to detect operational status and a second sensor to sense rotational movement of the rotary member. A controller is configured to detect initiation of a dispensing event on the basis of signals generated by the first sensor and detect completion of the dispensing event and / or completion of the retraction movement on the basis of signals generated by the second sensor.SELECTED DRAWING: Figure 10

Description

[Background technology]

[0001] The present disclosure relates to drug delivery devices, and in particular to sensing systems within drug delivery devices.

[0002] Drug delivery devices, including syringes, are widely used by medical professionals and patients who self-medicate. Patients suffering from many different diseases must frequently inject themselves with medication, and various devices have been developed to facilitate such self-medication. Such devices typically include a syringe with a syringe barrel that holds the medication, and a drive system for expelling the medication from the syringe barrel through the needle hole to the patient. The device may be an automatic injection device, which includes a mechanism that automatically performs some of the steps of the injection process, making it more convenient for patients to self-medicate. Due to the structure and design of such devices, it is difficult to determine the operating status of the device. While many functional drug delivery devices are currently available, improvements in such drug delivery devices are still desirable. Summary of the Invention

[0003] According to an embodiment of the present disclosure, the drug delivery device includes a housing, a drug container, a drive mechanism, a retraction mechanism, and a detection system. The drug container includes a container body for holding a drug and a slidable piston operably coupled to the container body. The slidable piston is movable relative to the container body to dispense the drug from the drug container. The drug container is movable relative to the housing between a storage position and a delivery position. The drive mechanism includes a plunger that engages with the slidable piston. The drive mechanism is adapted to axially drive the plunger to move the drug container from the storage position to the delivery position and to move the slidable piston to dispense the drug from the drug container in a dispensing event. The retraction mechanism is adapted to move the drug container from the delivery position to the storage position in a retraction movement. The retraction mechanism includes a rotating member configured to rotate during the retraction movement. The detection system includes a first sensor disposed in the drug delivery device. The first sensor is configured to generate a plurality of first signals indicative of a first sensed parameter. The detection system includes a second sensor disposed within the medication delivery device and positioned to detect rotational movement of the rotating member. The second sensor is configured to generate a plurality of second signals indicative of the detected rotational movement of the rotating member. The controller is operably coupled to the first sensor and the second sensor. The controller is configured to determine a start of a medication event based on the plurality of first signals generated by the first sensor, and is configured to determine at least one of a completion of a medication event and a completion of a retraction movement based on the plurality of second signals generated by the second sensor.

[0004] According to an embodiment of the present disclosure, a method for determining an operating state of a medication delivery device is provided. The device includes a needle, a first sensor, a second sensor, a rotation sensor, and a retraction mechanism. The method includes one or more of the following steps: The step includes determining a start of a dosing event from the needle in an extended position based on signal spikes of a plurality of first signals generated by the first sensor. The step includes determining an end of a dosing event from the needle in an extended position based on initial spikes of a plurality of second signals generated by a second sensor that detects rotation of a rotating member of the retraction mechanism. The step includes determining an end of needle retraction of the needle from the extended position based on a predetermined spike of the second signal generated by the second sensor following the initial spike of the second signal. The step includes indicating at least one of the determined start of the dosing event, the determined completion of the dosing event, and the determined completion of the needle retraction on a user interface.

[0005] According to an embodiment of the present disclosure, a drug delivery device includes a housing, a drug container, a drive mechanism, a retraction mechanism, an accelerometer, and a controller. The drug container includes a container body for holding a drug and a slidable piston operably coupled to the container body, the slidable piston being movable relative to the container body to dispense the drug from the drug container. The drug container is movable relative to the housing between a storage position and a delivery position. The drive mechanism is adapted to drive the drug container from the storage position until the drug container stops at the delivery position when a dispensing event is initiated. The retraction mechanism is adapted to drive the drug container from the delivery position until the drug container stops at the storage position when a retraction movement is initiated. The accelerometer is disposed in the drug delivery device and configured to detect a first acceleration caused by the drug container when driven from the storage position to the delivery position by the drive mechanism, and configured to detect a second acceleration caused by the drug container when driven from the delivery position to the storage position by the retraction mechanism. The controller is operatively coupled to the accelerometer and configured to determine a start of a dispensing event based on the detected first acceleration, and a completion of a retraction movement based on the detected second acceleration. [Brief description of the drawings]

[0006] The above-mentioned and other features of the present disclosure, and the manner in which they are accomplished, will become more apparent, and the invention itself will be better understood, by referring to the following description of embodiments of the present disclosure in conjunction with the accompanying drawings, in which:

[0007] [Figure 1] 1 is a cross-sectional side view of an exemplary medication delivery device including an exemplary sensing system prior to use. [Diagram 2] FIG. 2 is a cross-sectional side view of the medication delivery device of FIG. 1 with the medication container in a stored position and ready for a medication event. [Diagram 3] 2 is a cross-sectional side view of the drug delivery device of FIG. 1 with the drug container in a delivery position. [Figure 4]FIG. 2 is a perspective view of an example of a plunger provided with the drug delivery device of FIG. 1. [Diagram 5] FIG. 2 is a perspective view of an example of a syringe carrier equipped with the medication delivery device of FIG. 1. [Figure 6] FIG. 2 is a perspective view of an example of an upper shuttle member comprising the drug delivery device of FIG. 1. [Figure 7] FIG. 2 is a perspective view of an example of a lower shuttle member comprising the drug delivery device of FIG. 1. [Figure 8] FIG. 2 is a perspective view of the drug delivery device of FIG. 1. [Figure 9] FIG. 2 is a partially cut-away perspective view of the drug delivery device of FIG. 1. [Figure 10] 2 is a partial cutaway perspective view of the medication delivery device of FIG. 1 showing an exemplary sensing system and a rotating member of the retraction mechanism in a first position. [Figure 11] 13 is another partial cutaway perspective view of the medication device of FIG. 1 showing the detection system with the rotating member of the retraction mechanism in different positions. [Figure 12] 2 is a perspective view of the sensing system and rotating member of the medication delivery device of FIG. 1 with surrounding components removed, illustrating the operation of each component. [Figure 13] 2 is a perspective view of the sensing system and rotating member of the medication delivery device of FIG. 1 with surrounding components removed, illustrating the operation of each component. [Figure 14] FIG. 1 is a schematic diagram of an exemplary sensing system for communicating data to an external separate device. [Figure 15] 4 is a chart showing a signal generated by a sensor of a detection system.

[0008] Corresponding reference characters indicate corresponding parts throughout the several views. Although the illustrations described herein illustrate embodiments of the present disclosure in one form, the embodiments disclosed below are not intended to be exhaustive or to be construed to limit the scope of the invention to the precise forms disclosed. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The automatic injection device, generally designated 20, has a trigger that, when actuated by a user, automatically drives the needle syringe of the device downward so that the needle protrudes beyond the lower end of the device housing and penetrates the user. The device then automatically begins to inject the drug contents of the syringe through the needle, after which the syringe is automatically retracted so that the needle is returned into the housing. A delay mechanism of the device helps to stage the operation to ensure that the drug contents are properly delivered before the needle syringe is retracted. When the device includes a hidden needle, the operating status of the device can be provided to the user via an indicator display, or light, and / or sound, for each step of the process during the entire cycle of drug delivery. Additionally, recording and / or communication of drug delivery events or malfunctions can be provided on the device to patients and medical professionals. As used herein, the terms "distal" and "proximal" refer to the axial location relative to the user and opposite the injection site when the device is directed for use at such site. For example, the proximal end of the housing refers to the top end of the housing furthest from such an injection site, and the distal end of the housing refers to the base or injection end of the housing closest to such an injection site.

[0010] An exemplary drug delivery device 20 is illustrated in FIGS. 1-3. The device 20 includes a syringe system 22, a drive mechanism generally designated 24, a retraction mechanism 26, and a detection system 28 (illustrated in FIGS. 10-11) coupled within a device tubular housing 38. The device 20 includes a delay mechanism including a shuttle assembly 60 to help stage the operation to ensure that the drug contents are properly delivered before the needle syringe is retracted. The syringe system 22 includes a container barrel body 30 made of glass or other suitable material configured to hold a drug, a slidable piston member 32, such as an elastomeric sealing member, operably coupled to the container body 30, and a hollow injection needle 34. A proximal end of the injection needle 34 is attached to a distal tip of the barrel body 30. The injection needle 34 is in fluid communication with the drug contents of the injection barrel body 30 and may be initially covered by a needle guard 42. Distal advancement of the piston member 32 within the barrel body 30 toward the injection needle 34 dispenses the medicament through the needle 34. A drive mechanism 24 is operably coupled to the piston member 32. As a result of operation of the drive mechanism 24, slidable movement of the piston member 32 relative to the container body 30 dispenses the medicament from the syringe system 22, as described below. Operation of the drive mechanism 24 and retraction mechanism 26 within the device 20, as well as other descriptions of exemplary device components, are described in U.S. Patent No. 8,734,394 to Adams et al., filed February 24, 2011, the disclosure of which is incorporated herein by reference.

[0011] FIG. 1 shows the medication delivery device 20 in a stored configuration. A syringe overcap 36 is secured to the housing 38 and covers a distal opening 40 of the housing 38. A needle guard 42 is attached to the distal tip of the barrel body 30 of the syringe 22 and covers the needle 34. The overcap 36 and needle guard 42 protect the user from accidental needle stick injuries and also protect against damage to the needle 34. When using the device 20 to administer a medication, e.g., to inject the medication into a patient, the overcap 36 and needle guard 42 are first removed to expose the distal opening 40. FIG. 2 shows the device 20 after removal of the overcap 36 and needle guard 42, with the syringe 22 in the stored position and the device 20 ready for a medication event.

[0012] The syringe system 22 is movable relative to the medication delivery device 20 between a stored position, shown in Figures 1-2, and a delivery position, shown in Figure 3. Figure 3 shows the device 20 after the syringe system 22 has been moved from its stored position to a delivery position relative to the device 20. In the stored position, the injection needle 34 is in a retracted position within the device 20 such that the distal tip of the needle 34 does not extend beyond the distal opening 40. In the delivery position, the distal tip of the needle 34 protrudes distally from the device 20 in the extended position beyond the distal opening 40 for operative insertion into a patient.

[0013] The drive mechanism 24 includes a plunger 44 for engaging relationship with the piston member 32. The drive mechanism 24 includes a drive spring 46 that, when released, drives the plunger 44 in a translational distal movement. In one example, the spring 46 advances the plunger 44 along a linear path defined by a central axis 48 of the device 20. The plunger 44 includes a distal region with a disk-shaped foot 50 ( FIG. 4 ) at one end that serves to operatively abut the sealing piston 32 during advancement of the plunger. Further advancement of the plunger 44 advances the syringe 22 along the axis 48 from its retracted position to its delivery position. The drive spring 46 directly biases downward to drive the plunger 44, thereby driving the piston 32 distally, whose drive motion shifts the syringe 22 distally relative to the shuttle assembly 60 and the housing 38, causing the tip of the needle 34 to protrude beyond the distal end of the housing to penetrate the user's skin and then force the syringe's medicament contents through the needle for injection. After the syringe 22 has been advanced to its delivery position, continued advancement of the plunger 44 advances the piston 32 within the barrel 30 to dispense the medicament from the needle 34 in a dosing event. Advancement of the plunger 44 generally does not result in dispensing of the medicament from the syringe 22 until the syringe 22 has been advanced to its delivery position. Two main factors prevent the medicament from being dispensed before the syringe has been advanced to its delivery position for dosing. First, friction between the piston 32 and the barrel 30. Typically, the piston 32 will be formed of a rubber material and the barrel 30 will be glass. The frictional resistance between these two components may be sufficient to prevent advancement of the piston 32 within the barrel 30 until the syringe 22 has advanced to its delivery position and engagement with a suitable stop member prevents further advancement of the syringe 22. Additionally, the medicament within the syringe may be somewhat viscous and thereby somewhat resistant to flow out of the needle 34. If desired, modification of the piston member 32 and the container body 30 to change the frictional resistance of the piston member 32 against the container body 30 may also limit or prevent premature dispensing of the medicament before the syringe 22 reaches its delivery position.

[0014] At the upper or proximal end of the housing 38 and projecting axially therefrom, a safety control button 52 is provided which is part of a user-operated trigger. When the safety sleeve of the housing is disposed in a proper angular orientation relative to the housing 38 so as to be rotatably adjusted by the user, the button 52 is unlocked and can be pressed to initiate the automatic injection function of the device. To activate the drive mechanism 24, a person would press the activation button 52 at the proximal end of the device 20. Pressing the button 52 disengages one or more elongated projections 54 of the plunger 44 from the shuttle assembly 60, thereby causing the spring 46 to advance the plunger 44 axially. The spring 46 has a helical shape and surrounds the projections 54. The distal end of the spring 46 biasingly engages a flange 56 on the plunger 44.

[0015] FIG. 4 shows one example of a plunger 44. The proximal region of the plunger includes one or more protrusions (a pair of protrusions 54 are shown). The protrusions 54 are configured to bend radially inward. In another example, the plunger includes a single protrusion. The foot 50 is positioned along the distal end of the plunger. An inclined surface 55 may be formed along the tip of the protrusion. An outrigger 58 depends distally from a flange 56 of the plunger 44 in a spaced-apart relationship from the plunger body. The outrigger 58 during injection directly engages a locking member to unlock a rotating member 70 of the delay mechanism (illustrated in FIG. 3). The rotating member 70 is also part of the retraction mechanism 26. The location of the outrigger 58 relative to the plunger 44 and the rotating member 70 is such that engagement between the outrigger and the rotating member corresponds to the completion of a dosing event. Depressing the button 52 causes a tab on the button 52 to engage a ramp 55 on the projection 54, urging the projection 54 inwardly to disengage the projection 54 from the upper shuttle member 62 (shown in FIG. 6) of the shuttle assembly 60 (shown in FIG. 2), corresponding to the initiation of a dosing event. After the projection 54 is disengaged, the spring 46 exerts a biasing force on the flange 56 to advance the plunger 44 from a first position, shown in FIG. 2, where the piston is at the proximal end of the container barrel body 30, to a final fully extended position, shown in FIG. 3, where the piston is at the distal end of the container barrel body 30.

[0016] The delay mechanism of the device 20 includes a shuttle assembly 60 (as shown in FIG. 2), a rotating member 70 (as shown in FIG. 3) that releasably latches with the shuttle assembly 60, and a spring 66 (as shown in FIG. 1) that acts between the shuttle and the rotating member. The shuttle assembly 60 may be formed from a single-piece shuttle. In the embodiment shown, the shuttle assembly 60 is formed from an upper shuttle 62 and a lower shuttle 64, further shown in FIGS. 6 and 7, respectively. The shuttle parts 62 and 64 may be fixedly connected, such as by a snap fit or other suitable connection method, during manufacturing assembly to function together as a shuttle assembly. The multi-piece construction facilitates molding and assembly of the shuttle, as well as assembly of the device components within the internal cavity of the shuttle. A suitable material for any one of the shuttle parts is a plastic, such as, for example, polycarbonate or an alloy thereof, which is transparent.

[0017] In final assembly, the upper shuttle member 62 captures the button 52 and the spring 46 to limit axial movement of these components in the proximal direction. The upper shuttle member 62 and the lower shuttle member 64 each include a tubular cylindrical body. A central opening 63 extends through the upper and lower shuttle member bodies to allow passage of the latching portion of the plunger projection 54. A guide formation, such as a dog, projects proximally from the upper surface of the upper shuttle member 62 around the opening 63 and serves to guide the actuation tab of the button 52 into the opening 63 during use. The projection 54 engages the upper surface of the upper shuttle 62 when the device is in the state shown in Figures 1 and 2. Depressing the button 52 moves the tab of the button 52 distally to engage the angled surface 55 of the projection 54, urging the projection 54 inwardly to disengage the projection 54 from the upper shuttle member 62. After projection 54 is disengaged and positioned within the cross-sectional area of ​​opening 63, spring 46 exerts a biasing force on flange 56 to advance plunger 44 from a first position shown in Figure 2 to a second position shown in Figure 3. As plunger 44 advances, syringe 22 advances to a delivery position and piston 32 then advances distally within syringe 22 to dispense the medication as described above.

[0018] After the dosing event is completed, the retraction mechanism 26 is configured to move the syringe 22 proximally from the delivery position shown in Figure 3 to a stored position shown in Figure 2 or to a more proximal position such as a housing covering the needle. In the embodiment shown, the retraction mechanism with delay mechanism includes a spring 66, a syringe carrier 68 shown in Figure 5, and a rotating member 70 that functions as a follower.

[0019] As the plunger 44 nears the end of its travel in the distal direction, an outrigger 58 on the plunger 44 unlocks the rotating member 70. With further reference to FIGS. 12-13, the rotating member 70 is rotationally secured to the lower shuttle member 64 by engagement between a latch 72 and a latch recess on the lower shuttle member 64. The outrigger 58 unlocks the member 70 by depressing the latch 72. A spring 66 is torsionally preloaded and has a distal end engaged with the rotating member 70 and an opposite proximal end engaged with the shuttle assembly 60. Depressing the latch 72 causes the spring 66 to rotate the rotating member 70. The member 70 includes a slot 74 (shown in FIG. 12) that receives a tab 78 on the lower shuttle member 64 (shown in FIG. 7). At one end of the circumferential slot 74 formed in the body of the rotating member 70, an axially extending channel 76 is defined in the rotating member body. Relative rotation between the rotating member 70 and the lower shuttle member 64 causes the tab 78 to move within the slot 74 until the tab 78 reaches the axially extending channel 76. At this position, the biasing spring 66 biases the axial separation between the rotating member 70 and the lower shuttle member.

[0020] Member 70 is rotatable within housing 38 about axis 48 but is axially fixed relative to housing 38 and shuttle assembly 60. An outer radial flange 82 defined along a body portion of rotating member 70 is configured to engage an inner ledge defined along the inner surface of housing member 38 to limit axial movement of member 70. Spring 66 exerts axial and / or torsional forces on member 70 to bias member 70 distally, thereby maintaining member 70 in an axial position where flange 82 engages the inner ledge of housing member 38. Shuttle assembly 60 includes axially extending channels and / or ribs that engage corresponding guide formations defined along the interior of housing member 38, thereby allowing shuttle assembly 60 to move axially within housing 38 and inhibiting relative rotation between shuttle assembly 60 and housing member 38.

[0021] The spring 66 is also axially preloaded and exerts a proximally directed biasing force on the shuttle assembly 60. Rotation of the rotating member 70 about the lower shuttle member 64 is driven by the spring 66 until the channels 76 are aligned with the shuttle tabs 78, respectively. In this arrangement, the tabs 78 are free of the ledges forming the slots 74, thereby unlatching the shuttle assembly 60 and the rotating member 70. When the tabs 78 reach the channels 76, the spring 66 moves the shuttle assembly 60 proximally within the housing 38 such that the tabs 78 slide axially through the channels 76. A damping compound can be disposed adjacent the rotating member 70 to slow down or otherwise control the rotation of the member 70 and allow for completion of the dosing event before the tabs 78 reach the channels 76. In the embodiment shown, the rotating member 70 includes a skirt with multiple axially extending tabs 80 that extend below the ledges 82, which are disposed within a grease collar to provide damping.

[0022] Proximal movement of the shuttle assembly 60 carries the syringe 22 proximally, returning it to the stored position shown in FIG. 2. A spring 66 biases the retraction mechanism 26 proximally, thereby maintaining the syringe 22 in its stored position after the dosing event. A locking mechanism, such as a detent on the shuttle assembly 60 and a recess on the housing member 38, may additionally provide a locking engagement to secure the syringe 22 in the stored position after the dosing event, such that the user can then dispose of or otherwise handle the device 20 in a safe manner.

[0023] The syringe carrier 68 is shown in FIG. 5. Arcuate arms 84 grip the barrel 30 of the syringe 22. The syringe carrier 68 also includes a radial flange 86 spaced from the circumferential base above the arms 84. The flange on the syringe barrel 30 is captured between the arms 84 and the flange 86. A portion of the underside 88 of the flange 86 engages a small flange 90 on the plunger 44, thereby preventing proximal axial movement of the syringe 22 before the plunger 44 has been advanced. When the shuttle assembly 60 is retracted, the lower shuttle member 64 engages the arms 84 to carry the syringe 22 proximally back to its stored position.

[0024] The detection system 28 is operable to detect and / or indicate an operating state process and indicate to a user or other person. In one example, the detection system 28 includes a sensor for detecting an initial state of the injection process. In another example, the detection system 28 includes a sensor for detecting intermediate and final states of the injection process. In another example, the detection system 28 includes a sensor for detecting all of the above states of the injection process. In another example, the detection system 28 includes a first sensor for detecting an initial state of the injection process and a second sensor for detecting intermediate and final states of the injection process. In one example of FIG. 14, the first sensor includes an accelerometer 92 and the second sensor includes an optical sensor 94. The optical sensor 94 includes a light emitter 96 and an optical sensor 98. In one example, the accelerometer 92 detects acceleration and / or movement of an associated component and is associated with the device housing 38 in a location that does not interfere with the movable components. For example, the accelerometer may be embedded in the device housing 38 or otherwise mounted along an interior of the device housing 38. In one example, the optical sensor 94 senses the coded pattern of an associated component and is associated with the device housing 38 in a location that does not interfere with the moveable components. For example, the optical sensor 94 may be embedded in the device housing 38 or otherwise mounted along the interior of the device housing 38. In another example, the accelerometer 92 and the optical sensor 94 may be associated with a single control module, as shown in FIG.

[0025] Various sensor systems are contemplated herein. In general, a sensor system includes one or more sensing components and one or more sensed components. The term "sensing component" refers to any component capable of detecting the relative position of a sensed component. A sensing component includes one or more sensing elements, or "sensors," associated with electrical components for operating the one or more sensing elements. A "sensed component" is any component, where the sensing component can detect the position and / or movement of the sensed component relative to the sensing component. For example, the sensed component may move axially and / or rotate relative to the sensing component, and can detect the linear and / or angular position and / or linear and / or rotational movement of the sensed component. A sensing component can include one or more sensing elements, and a sensed component can include one or more sensed elements. One or more sensing components of a sensor system can detect the position or movement of the sensed component(s) and provide an output representative of the position(s) or movement(s) of the sensed component(s). A sensor system typically detects a characteristic of a sensed parameter that varies in relation to the position and / or movement of one or more sensed elements within a sensed region. The sensed element extends into or otherwise influences the sensed region in a manner that directly or indirectly affects the characteristics of the sensed parameter. The relative positions of the sensing component(s) and the sensed component(s) affect the characteristics of the sensed parameter, allowing the controller of the sensor system to determine different positions of the sensed element(s). A suitable sensor system may include a combination of active components (e.g., powered or connected to a power source or controller) and passive components (e.g., unpowered or not connected to a power source or controller). Either the sensing component or the sensed component may operate as an active component. If one component is operating as an active component, the other component need not operate as an active component, but may instead operate as a passive component.Any of a variety of sensing technologies capable of detecting the relative position of the two members may be incorporated. Such technologies may include, for example, tactile, optical, inductive or electrical measurement based technologies. Such technologies may include measurement of a sensed parameter associated with a field or electrical parameter, such as an electric / magnetic field. In one form, a magnetic sensor detects changes in the sensed magnetic field as the magnetic component is moved relative to the sensor. In another embodiment, the sensor system may detect changes to the characteristics of and / or to the electric / magnetic field when an object is positioned in and / or moved through the magnetic field. The field variations change the characteristics of the sensed parameter associated with the position of the sensed element within the sensed region. In such an embodiment, the sensed parameter may be capacitance, conductance, resistance, impedance, voltage, inductance, etc. For example, a magnetoresistive sensor detects distortions in an applied magnetic field that result in a characteristic change in the resistance of an element of the sensor. As another example, a Hall effect sensor detects a change in voltage resulting from distortion of an applied magnetic field. In one example, the second sensor is a magnetic sensor and the rotating component includes a magnetic property.

[0026] In Figs. 12-13, an encoder strip 112 is formed along the outer circumferential surface 99 of the rotating member 70. In one example, the encoder strip is disposed axially along the outer body of the rotating member 70 between the shelf 82 and the slot 74. The encoder strip 112 includes a plurality of targets 114 that are circumferentially spaced apart from one another and are recognizable by the optical sensor 94 of the detection system 28. For example, the targets 114 may be formed by individually recognizable targets that use different colors in the spaces between the targets. In another example, the targets include a continuous gradient of two different colors to provide a variable signal. Alternatively, the targets 114 may be provided with different surface treatments. For example, the targets 114 may be provided with a rough surface treatment to scatter light while the spaces between the targets 114 are smooth and reflective.

[0027] The sensor system 28 also includes a controller 100 having electronic circuitry with a processor 102, a clock or timer (not shown) for date / time tracking and stamping, and a storage device (not shown). Data may be stored in a storage device, such as, for example, RAM, PROM, an optical storage device, a flash memory device, a hardware storage device, a magnetic storage device, or any suitable computer-readable storage medium. The data may be accessed and manipulated according to instructions from the processor 102.

[0028] Both the accelerometer 92 and the optical sensor 94 are electronically connected to the controller 100 and operatively coupled to the processor 102. The sensor system 28 may optionally include a user interface 104. The user interface 104 may take the form of an LCD screen or, in a more simplified form, one or more LED lights. The system 28 also includes a power source 110, if present, that provides power to the sensors 92, 94, the processor 102, and the user interface 104. The user interface may be a separate display screen positioned along the device housing. If the device 20 is a disposable device designed for a single injection procedure, the power source 110 may be sized to provide sufficient power only for a single procedure. If the device 20 is intended for multiple uses, a rechargeable or easily replaceable power source, such as a rechargeable or disposable battery, may be used. In the embodiment shown, the device 20 is a one-time disposable device.

[0029] The controller 100 may include a communication unit (such as a transmitter and / or a receiver or transceiver) for communicating with a separate device 106, as illustrated diagrammatically in FIG. 14. The separate device 106 may take the form of a smartphone having a user interface 108. The communication unit (not shown) is configured to communicate unidirectionally or bidirectionally with the separate device 106, including the user interface 108, which may communicate the occurrence of these events. In one example, the communication unit includes a low-power high-frequency wireless transceiver that utilizes wireless technology standards for exchanging data, such as those based on the IEEE 802.15 standard, including, but not limited to, Bluetooth (e.g., Bluetooth Standard, Low Energy, Smart) and Zigbee, ANT and ANT+ protocols, or Near Field Communication (NFC) using an NFC chip. Other suitable wireless communication protocols, such as WI-FI, may be used. Generally, it is most convenient to communicate wirelessly with another device, but it is also possible to use a wired connection for such communication. The device housing may include an electrical connector (not shown) operably connected with the controller. The electrical connector may be configured as a USB connector (such as, for example, a Series Standard-A, Standard-B, Standard-C, Mini-A, Mini-B, Micro-A, or Micro-B connector), a serial port connector, a video graphics array (VGA) connector, a D-subminiature connector, a BNC connector, or a mini-DIN connector. Additionally, the electrical connector may be a male or female connector.

[0030] As can be most easily seen in Figs. 8-11, the sensor system 28 is mounted on the housing so that the accelerometer 92 can be disposed on the medication delivery device to sense the movement and velocity of the housing 38 or components within the housing 38. After the user presses the actuator button 52 to initiate a medication event, the drive spring 46 accelerates the plunger 44 and the syringe in a distal direction as the spring 46 acts on the plunger 44 until the syringe 22 hits an axial stop at its delivery position and stops any further distal movement. This change in acceleration creates the movement and force sensed by the accelerometer 92. The timing of the syringe 22 reaching its delivery position and the movement of the piston 32 to administer the medication through the needle can be pre-determined and precise. In other words, the initiation of a medication event can be associated with the arrival of the syringe at its delivery position and a sudden stop. A retraction event occurs to move the syringe from the delivery position to the retracted position. Upward (proximal) acceleration of the syringe during a retraction event imparts a smaller acceleration in the opposite direction to the injector body. The timing and magnitude of these formations can be detected and analyzed to detect the start of a dosing event and the start and / or completion of a retraction event, and to detect variations in the advancement and retraction performance of the syringe.

[0031] The chart shown in Figure 15 provides a simplified representation of the output of the sensors 92, 94. Line 120 represents a signal generated by the accelerometer 92 indicating the sensed acceleration and communicated to the processor 102. A spike 122 in the accelerometer signal represents the start of a dispensing event when the movement of the syringe 22 to the delivery position suddenly stops. The further advancing plunger 44 moves the piston 32 to dispense the medication from the syringe 22. Once the dispensing event begins, the vibration of the housing 38 caused by the stopping of the syringe 22 decreases in magnitude as shown by line 120.

[0032] As the plunger 44 nears the end of its distal advancement, the outrigger 58 on the plunger 44 unlocks the rotating member 70, which then begins to rotate about the axis 48, as discussed in more detail above. The optical sensor 94 may be positioned to detect the rotational movement of the rotating member 70 by detecting the passage of individual targets 114. The optical sensor 94 generates signals indicative of the detected rotational movement of the rotating member 70 and communicates these signals to the processor 102. The dashed line 124 in the chart of FIG. 15 represents the signal generated by the optical sensor 94. Also, as the plunger 44 unlocks the rotating member 70 and begins to rotate the member 70, the retraction movement of the retraction mechanism 26 begins. This retraction movement moves the syringe 22 from its delivery position (FIG. 3) to its storage position (FIG. 2).

[0033] As best seen in Figures 12 and 13, the optical sensor 94 is positioned to monitor the rotational movement of the member 70. Figure 12 depicts the position of the optical sensor 94 relative to the member 70 when the rotational movement of the member 70 is initially initiated. Arrow 116 indicates the direction in which the member 70 rotates relative to the sensor assembly 28. As the member 70 rotates, the targets 114 of the encoder strip 112 are recognized by the optical sensor 94 as each individual target 114 rotates past the optical sensor 94. Figure 13 illustrates the member 70 when its rotational movement is complete and the tabs 78 are aligned with the channels 76 such that the shuttle 60 is retracted distally by the spring 66, returning the syringe 22 to its retracted position.

[0034] The line 124 in FIG. 15 represents the signal communicated by the optical sensor 94. In one example, the optical sensor signal is a binary signal, such that the absence of a signal (value 0 in FIG. 15) indicates that the sensor does not detect the target 114, and the communication of a signal (value 1 in FIG. 15) indicates that the sensor recognizes the target. Thus, the spike portion 126 of the sensor signal line in FIG. 15 represents the passing of the target 114 behind the optical sensor 94. In another example, the encoder strip 112 may include a continuous gradient from black to white, such that the optical sensor signal is a variable signal. In one example, the optical sensor 94 may be configured to communicate analog values ​​sampled by the controller 100 to provide a finer amount of resolution for rotational position and velocity.

[0035] When the optical sensor 94 first recognizes the passage of the target 114, as represented by the start spike point 128 of the line 124, represents when the rotating member 70 is unlocked and begins to rotate. As such, this point also corresponds to the completion of the dosing event. In this regard, it is noted that the completion of the dosing event may directly correspond to the time represented by point 128 or may have a known correlation to this time, such as, for example, the completion of the dosing event may occur 0.2 seconds after the time represented by point 128. In either event, point 128 signifies that a retraction movement of the retraction mechanism 26, such as the rotation of the rotating member 70, has begun.

[0036] The arc through which the member 70 must rotate to complete its rotational movement and align the channel 76 with the tab 78 is known in advance. Thus, the number of targets 114 through which the member 70 must pass the optical sensor 94 to complete its rotational movement is also known in advance. In the illustrated embodiment, when the fifth target 114 is recognized by the sensor 94, as indicated by reference number 130 in FIG. 15, the rotating member 70 should complete its rotational movement and align the channel 76 with the tab 78. Once this occurs, the shuttle member 60 moves proximally and the syringe 22 moves to its retracted position to complete the retraction movement. In this regard, it is noted that the completion of the retraction event may correspond directly to the time represented by point 130, which may also correspond to the complete end of the device's operating cycle. Alternatively, the completion of the retraction event may have a known correlation to the time represented by point 130, for example, the completion of the retraction event may occur 0.2 seconds after the time represented by point 130.

[0037] In the illustrated embodiment, as described above, the controller 100 is configured to detect the start of a dispensing event based on a signal generated by the accelerometer 92. More specifically, the controller 100 is configured to determine the start of a dispensing event based on a spike 122 in the signal generated from the accelerometer 92. The controller 100 is also configured to determine the completion of a dispensing event and the completion of a retraction movement based on a signal generated by the optical sensor 94. For example, the controller 100 is configured to determine an initial recognition of a rotational movement as the completion of a dispensing event (either with or without compensation) based on an initial point 128 of the signal line 124. The controller 100 is configured to determine a final recognition of a rotational movement as the completion of a retraction event (either with or without compensation) based on a point 130 of the signal line 124. In one example, the controller 100 also counts the number of targets recognized by the sensor 94, and when the appropriate number of targets have been counted indicating that the member 70 has fully completed its rotational movement, the controller 100 interprets this as the completion of the retraction movement and the successful return of the syringe 22 to the retracted position. The controller 100 may be configured to detect the end of the dispensing or retraction event based on a signal generated by the accelerometer 92, which may be independent of or in addition to the optical sensing signal at point 130. As the needle retracts under the spring force, based on the position of the rotating member 70, the sudden stopping of the subassembly within the device when it reaches the final retracted position generates a detectable acceleration. More specifically, the controller 100 is configured to determine the end of the event based on a spike or valley in the signal generated from the accelerometer 92 (not shown in FIG. 15, but located approximately at time 26 seconds). When both the accelerometer and optical sensing are used to detect the end of a delivery cycle, the controller 100 can compare each signal for reliability or redundancy in detecting a malfunction in the syringe position or advancement. Other characteristics of the accelerometer 92 may be useful in detecting a malfunction in the syringe position or advancement.One occurs when the syringe 22 moves to the extended position, before hitting a hard stop. When the drive spring 46 initially accelerates the syringe 22 forward, a small acceleration is imparted to the injector housing 38 that can be detected. Another occurs when the rotating member 70 enables the operation of the dual function biasing member 66. An upward acceleration of the syringe 22 imparts a small acceleration in the opposite direction to the injector housing 38. By detecting and analyzing the timing and magnitude of these formations, the controller 100 can detect the start of a dispense event and the start and / or completion of a retraction event, and variations in the syringe advancement and retraction performance can be detected and indicated and / or communicated.

[0038] The operating status of the device determined from such information may also be communicated to the user. To this end, the controller 100 is configured to generate an output signal for each of the determined steps for display or other user feedback indication in response to the determining steps. For example, the sensor system 28 may generate a signal indicative of the initiation of a determined dispensing event. The sensor system 28 may generate another signal indicative of the completion of a determined dispensing event. The sensor system 28 may generate another signal indicative of the initiation of a determined retraction movement. The sensor system 28 may also generate another signal indicative of the completion of a determined retraction movement. Any one or combination of these output signals may be communicated to the user interface 104 to thereby notify the user of the occurrence of the initiation of a dispensing event, the completion of a dispensing event, the initiation of a retraction movement, and / or the completion of a retraction movement. For example, an LCD screen or LED lights on the device 20 may notify the occurrence of these events.

[0039] In addition to simply recognizing when a particular event occurs, the controller 100 may be configured to analyze the sensor signal to identify a malfunction. In one example, the controller 100 is configured to monitor the signal from the optical sensor 94 to ensure that the rotating member 70 has fully completed its rotation and the syringe 22 is retracted to the storage position. If the rotating member 70 does not rotate through a sufficiently large rotational arc (e.g., only three of the five lines 126 of the signal lines 124 in FIG. 15 are monitored), the controller 100 may be configured to identify this as a malfunction of the retraction movement. If the signal generated by the optical sensor 94 indicates that the rotating member 70 has not fully completed its rotational movement, the controller 100 may be configured to determine that the drug container did not successfully move from the delivery position to the storage position during the retraction movement.

[0040] The controller 100 may also be configured to determine the duration of the dispensing event based on the time interval between the spike 122 of the accelerometer signal 120 and the onset point 128 of the optical sensor signal 124 (or detection of the acceleration associated with the retraction event, as described above). If the duration of the dispensing event is shorter or longer than a predetermined threshold range, the processor may determine such an event and flag it as a malfunction. Alternatively, if the duration is within an acceptable range for the amount of medication being dispensed, it may be considered a successful medication delivery. When a malfunction occurs, the controller 100 may be configured to communicate with the user interface for displaying a warning or flashing an LED (red LED). Such an event may be recorded and communicated to a medical professional.

[0041] Information obtained from such signals may be recorded in memory along with the date and time of the drug dispensing event. This recorded data may then be communicated via wireless connection and / or internet to a separate remote device 106 (such as a cell phone, laptop, and / or server database), or to a caregiver. The device 106 may keep a log of all such drug delivery events, including the date and time of the drug delivery event, and whether a malfunction was detected. The device 106 may also communicate such information over a network to a medical professional, who may maintain a log of such drug delivery events. The controller 100 may also be configured to record in memory and communicate the type and amount of drug dispensed. In the case of a one-time disposable device, this information should be known in advance, whereby the record would facilitate communication of the type and amount of drug delivered in a delivery event. The user's ability to automatically generate a log of drug delivery events may be very useful to users who inject drugs on a regular basis and find it tedious or inconvenient to maintain such a log of drug delivery events.

[0042] As can be seen, the sensor system 28, with the exception of the encoder strip 112, which is positioned on the rotatable member 70, is packaged within a single small housing that is mounted on the housing 38. As such, it may be permanently mounted on the device 20 or may be removable and reused on multiple devices such that the device has a rotatable member 70 with a mounting interface for receiving the encoder strip 112 and the sensor system 28.

[0043] In one example, an exemplary method for determining an operating state of the device 20 is provided. The method may include determining the start of a dosing event. The controller 100 is configured to determine the start of a dosing event based on a first signal generated by a first sensor. When the first sensor is an accelerometer, an initial spike in the signal may be due to the syringe suddenly stopping as it moves from a retracted position to a delivery position. Another step may include determining the end of a dosing event. The arrangement of the plunger outrigger and the rotating follower is such that the engagement between the outrigger and the rotating follower, such that the start of the rotation of the follower is the moment the dosing event is completed. The controller 100 is configured to determine the completion of a dosing event based on an initial spike in a second signal generated by a second sensor. Another step may include determining the end of retraction and / or the completion of a drug delivery cycle. The controller 100 is configured to determine completion of the retraction movement based on a predetermined spike in the second signal generated by the second sensor or based on detection of an acceleration caused by retraction of the syringe into the device housing. The method may include indicating the start of the determined dosing event, the completion of the determined dosing event, the start of the determined retraction, the completion of the determined retraction or delivery cycle, or any combination thereof. The controller may further be configured to communicate any of the indicated events to an on-board user indicator, or a remote user indicator external to the device. The method may include determining a malfunction of the operation of the device. The controller may be configured to analyze parameters of the sensors based on the first and / or second signals from the respective sensors, to compare such parameters to threshold ranges stored in the storage device, and, if outside the threshold ranges, to communicate any determined malfunction to an on-board user indicator or a remote user indicator external to the device.

[0044] While this invention has been described as having an exemplary design, the invention may be further modified within the spirit and scope of the disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles.

[0045] Various aspects are described in this disclosure, including but not limited to the following aspects.

[0046] 1. A medication delivery device comprising: a housing; a medication container having a container body for holding a medication and a slidable piston operatively coupled to the container body, the slidable piston being movable relative to the container body to dispense the medication from the medication container, the medication container being movable relative to the housing between a stored position and a delivery position; a drive mechanism including a plunger engaged with the slidable piston, the drive mechanism adapted to axially drive the plunger to move the medication container from the stored position to a delivery position and to move the slidable piston to dispense the medication from the medication container in a dispensing event; and a retraction mechanism adapted to move the medication container from the delivery position to the stored position in a retraction movement, the retraction mechanism configured to rotate during the retraction movement. a retraction mechanism including a rotating member rotating in a direction perpendicular to the retraction mechanism; a detection system including a first sensor disposed within the medication delivery device and configured to generate a plurality of first signals indicative of a first sensed parameter; a second sensor disposed within the medication delivery device and positioned to detect rotational movement of the rotating member and configured to generate a plurality of second signals indicative of the sensed rotational movement of the rotating member; and a controller operatively coupled to the first sensor and the second sensor, wherein the controller is configured to determine a start of a dispensing event based on the plurality of first signals generated by the first sensor, and to determine at least one of a completion of a dispensing event and a completion of a retraction movement based on the plurality of second signals generated by the second sensor.

[0047] 2. The device of aspect 1, comprising a user interface operably coupled to a controller, the controller configured to communicate to the user interface at least one of a start of a dosing event, and a completion of the dosing event and a completion of a retraction movement.

[0048] 3. The device of aspect 2, wherein the user interface is disposed on the device.

[0049] 4. The device of aspect 2, wherein the user interface is separate from the device and the controller is configured to wirelessly communicate to the user interface the initiation of a dosing event, and at least one of completion of the dosing event and completion of the retraction movement.

[0050] 5. The device of any one of aspects 1-4, wherein the controller is configured to determine a malfunction from an analysis of at least one of the first signal and the second signal.

[0051] 6. The device of any one of aspects 1-5, wherein the controller is configured to determine a duration of the dosing event based on the first signal and the second signal.

[0052] 7. The device of any one of aspects 1-6, wherein the controller is configured to determine a malfunction from analysis of the second signal to determine whether movement of the drug container from the delivery position to the storage position is unsuccessful when the device performs a retraction movement.

[0053] 8. The device of aspect 7, wherein the second sensor is an optical sensor and the rotating member defines a plurality of sensor targets recognizable by the optical sensor.

[0054] 9. The device of any one of aspects 1-8, wherein the sensor system is configured to record data regarding a medication event based on the first signal and the second signal.

[0055] 10. The device of aspect 9, wherein the sensor system is configured to communicate recorded data to a separate device.

[0056] 11. The device of aspect 10, wherein the recorded data being communicated by the sensor system includes a date and time of a medication event.

[0057] 12. The device of aspect 10, wherein the controller is configured to determine a malfunction from an analysis of at least one of the first signal and the second signal.

[0058] 13. The device of any one of aspects 1-12, wherein the drive mechanism includes a spring for driving the plunger and the drug container, and the controller is configured to determine a malfunction from analysis of the second signal when the device performs a retraction movement to determine whether movement of the drug container from the delivery position to the storage position is unsuccessful.

[0059] 14. A drug delivery device comprising: a syringe having a barrel for holding a drug and a piston disposed within the barrel, the syringe further including a hollow needle, movement of the piston relative to the barrel dispenses the drug through the needle, the syringe being movable relative to the drug delivery device between a stored position and a delivery position, the needle extending from the device at the delivery position and retracted into the device at the stored position; a drive mechanism having a plunger for advancing the piston, the drive mechanism including a spring adapted to drive the plunger in a translational movement to move the syringe from the stored position to the delivery position and to advance the piston within the barrel to dispense the drug from the syringe in a dosing event; and a retraction mechanism adapted to move the syringe from the delivery position to the stored position in a retraction movement, the retraction mechanism comprising a spring adapted to move the plunger in a translational movement to move the syringe from the stored position to the delivery position and to advance the piston within the barrel to dispense the drug from the syringe in a dosing event. 1. A device comprising: a retraction mechanism including a rotating member configured to rotate during movement; a detection system comprising: an accelerometer disposed on the medication delivery device and configured to generate a plurality of first signals indicative of a detected acceleration; an optical sensor disposed on the medication delivery device and positioned to detect rotational movement of the rotating member and configured to generate a plurality of second signals indicative of the detected rotational movement of the rotating member; and a controller operably coupled to the accelerometer and the optical sensor, wherein the controller is configured to determine a start of a medication event based on the plurality of first signals generated by the accelerometer, and to determine at least one of completion of a medication event and completion of the retraction movement based on the plurality of second signals generated by the optical sensor.

[0060] 15. The device of aspect 14, wherein the sensor system is configured to record data regarding each medication event based on a plurality of first and second signals, and to communicate the recorded data to a separate device.

[0061] 16. The device of any one of aspects 14-15, wherein the controller is configured to determine a malfunction from at least one of the first signal and the second signal.

[0062] 17. A device described in any one of aspects 14 to 16, wherein the outer surface of the rotating member includes a plurality of sensor targets recognizable by an optical sensor, and when the device performs a retraction movement, the controller is configured to determine from analysis of a plurality of second signals whether movement of the drug container from the delivery position to the storage position is successful.

[0063] 18. The device of any one of aspects 14-17, wherein the controller is configured to determine a duration of the dosing event based on a signal spike from the first signal and an initial spike from the second signal.

[0064] 19. A device as described in any one of aspects 14-18, wherein the sensor system communicates the start of the medication event, the completion of the medication event, and the completion of the retraction movement to a user interface, thereby notifying a user of the occurrence of the start of the medication event, the completion of the medication event, and the completion of the retraction movement.

[0065] 20. The device of aspect 19, wherein the user interface is disposed on a separate device that receives the recorded data.

[0066] 21. A method for determining an operating state of a medication delivery device having a needle, a first sensor, a second sensor, a rotation sensor, and a retraction mechanism, the method comprising: determining a start of a medication event from the needle in an extended position based on signal spikes of a plurality of first signals generated by the first sensor; determining an end of a medication event from the needle in an extended position based on initial spikes of a plurality of second signals generated by a second sensor that detects rotation of a rotating member of the retraction mechanism; determining an end of needle retraction of the needle from the extended position based on a predetermined spike of the second signal following the initial spike of the second signal generated by the second sensor; and indicating at least one of the determined start of the medication event, the determined completion of the medication event, and the determined completion of the needle retraction on a user interface.

Claims

1. 1. A drug delivery device comprising: Housing and a medicament container having a container body for holding a medicament and a slidable piston operatively associated with the container body, the slidable piston being movable relative to the container body to dispense a medicament from the medicament container, the medicament container being movable relative to the housing between a stored position and a delivery position; a drive mechanism including a plunger engaged with the slidable piston, the drive mechanism adapted to axially drive the plunger to move the medicament container from the storage position to the delivery position and to move the slidable piston to dispense medicament from the medicament container in a dispensing event; a retraction mechanism adapted to move the medicament container from the delivery position to the storage position in a retraction movement, the retraction mechanism including a rotating member configured to rotate during the retraction movement; 11. A device comprising: a detection system comprising: a first sensor disposed within the medication delivery device and configured to generate a plurality of first signals indicative of a first detected parameter; a second sensor disposed within the medication delivery device and positioned to detect rotational movement of the rotating member and configured to generate a plurality of second signals indicative of the detected rotational movement of the rotating member; and a controller operably coupled to the first sensor and the second sensor, wherein the controller is configured to determine a start of the medication event based on the plurality of first signals generated by the first sensor, and to determine at least one of a completion of the medication event and a completion of the retraction movement based on the plurality of second signals generated by the second sensor.

2. 13. The device of claim 1, further comprising a user interface operably coupled to the controller, the controller configured to communicate to the user interface a start of the dispensing event and at least one of a completion of the dispensing event and a completion of the retraction movement.

3. The device of claim 2 , wherein the user interface is disposed on the device.

4. 3. The device of claim 2, wherein the user interface is separate from the device, and the controller is configured to wirelessly communicate to the user interface the initiation of the medication event and at least one of the completion of the medication event and the completion of the retraction movement.

5. The device of claim 1 , wherein the controller is configured to determine a malfunction from an analysis of at least one of the first signal and the second signal.

6. The device of claim 1 , wherein the controller is configured to determine a duration of a dosing event based on the first signal and the second signal.

7. The device of claim 1 , wherein the controller is configured to determine a malfunction from analysis of the second signal to determine whether movement of the drug container from the delivery position to the storage position is unsuccessful when the device performs a retraction movement.

8. The device of claim 7 , wherein the second sensor is an optical sensor, and the rotating member defines a plurality of sensor targets visible by the optical sensor.

9. The device of claim 1 , wherein the sensor system is configured to record data regarding a medication event based on the first signal and the second signal.

10. The device of claim 9 , wherein the sensor system is configured to communicate the recorded data to a separate device.

11. The device of claim 10 , wherein the recorded data communicated by the sensor system includes a date and time of the medication event.

12. The device of claim 10 , wherein the controller is configured to determine a malfunction from an analysis of at least one of the first signal and the second signal.

13. The device of claim 12, wherein the drive mechanism includes a spring for driving the plunger and the drug container, and the controller is configured to determine a malfunction from analysis of the second signal to determine whether movement of the drug container from the delivery position to the storage position is unsuccessful when the device performs a retraction movement.

14. 1. A drug delivery device comprising: a syringe having a barrel for holding a medicament and a piston disposed within the barrel, the syringe further including a hollow needle, movement of the piston relative to the barrel dispenses a medicament through the needle, the syringe being movable relative to the medicament delivery device between a stored position and a delivery position, the needle extending from the device in the delivery position and retracted within the device in the stored position; a drive mechanism having a plunger for advancing the piston, the drive mechanism including a spring adapted to drive the plunger in a translational movement to move the syringe from the storage position to the delivery position and advance the piston within the barrel to dispense medicament from the syringe during a dosing event; a retraction mechanism adapted to move the syringe from the delivery position to the storage position in a retraction movement, the retraction mechanism including a rotating member configured to rotate during the retraction movement; 11. A device comprising: a detection system comprising: an accelerometer disposed on the medication delivery device and configured to generate a plurality of first signals indicative of a detected acceleration; an optical sensor disposed on the medication delivery device and positioned to detect rotational movement of the rotating member and configured to generate a plurality of second signals indicative of the detected rotational movement of the rotating member; and a controller operably coupled to the accelerometer and the optical sensor, wherein the controller is configured to determine a start of the medication event based on the plurality of first signals generated by the accelerometer, and to determine at least one of a completion of the medication event and a completion of the retraction movement based on the plurality of second signals generated by the optical sensor.

15. 15. The device of claim 14, wherein the sensor system is configured to record data regarding each medication event based on the plurality of first signals and the plurality of second signals, and to communicate the recorded data to a separate device.

16. The device of claim 15 , wherein the controller is configured to determine a malfunction from at least one of the first signal and the second signal.

17. The device of claim 16, wherein the outer peripheral surface of the rotating member includes a plurality of sensor targets recognizable by the optical sensor, and the controller is configured to determine from analysis of the plurality of second signals whether movement of the drug container from the delivery position to the storage position is successful when the device performs a retraction movement.

18. 20. The device of claim 17, wherein the controller is configured to determine a duration of a dosing event based on a signal spike from the first signal and an initial spike from the second signal.

19. 20. The device of claim 18, wherein the sensor system communicates at least one of the initiation of the medication event, the completion of the medication event, and the completion of the retraction movement to a user interface, thereby notifying the user of the occurrence of at least one of the initiation of the medication event, the completion of the medication event, and the completion of the retraction movement.

20. The device of claim 19 , wherein the user interface is disposed on the separate device that receives the recorded data.

21. 1. A method for determining an operational state of a medication delivery device having a needle, a first sensor, a second sensor, a rotational sensor, and a retraction mechanism, comprising: determining an initiation of a dispensing event from the needle in an extended position based on signal spikes of a plurality of first signals generated by the first sensor; determining an end of the dispensing event with the needle in the extended position based on an initial spike of a second plurality of signals generated by a second sensor that senses rotation of a rotatable member of a retraction mechanism; determining an end of needle retraction of the needle from the extended position based on a predetermined spike in a second signal generated by the second sensor following the initial spike in the second signal; indicating on a user interface at least one of the determined initiation of the medication event, the determined completion of the medication event, and the determined completion of the needle retraction.

22. 1. A drug delivery device comprising: Housing and a medicament container having a container body for holding a medicament and a slidable piston operatively associated with the container body, the slidable piston being movable relative to the container body to dispense a medicament from the medicament container, the medicament container being movable relative to the housing between a stored position and a delivery position; a drive mechanism adapted to drive the medicament container from the storage position to the delivery position when a dispensing event is initiated; a retraction mechanism adapted to drive the medicament container from the delivery position to the storage position when a retraction movement is initiated; an accelerometer disposed within the medication delivery device, the accelerometer configured to detect a first acceleration caused by the medication container when driven by the drive mechanism from the storage position to the delivery position, and configured to detect a second acceleration caused by the medication container when driven by the retraction mechanism from the delivery position to the storage position; a controller operably coupled to the accelerometer, the controller configured to determine a start of the dispensing event based on the detected first acceleration, and a completion of the retraction movement based on the detected second acceleration.

23. 23. The device of claim 22, comprising a user interface communicatively coupled to the controller, the controller configured to communicate to the user interface a start of the dispensing event and at least one of a completion of the dispensing event and a completion of the retraction movement.

24. The device of claim 23 , wherein the user interface is disposed on the device.

25. 24. The device of claim 23, wherein the user interface is separate from the device, and the controller is configured to wirelessly communicate to the user interface the initiation of the dispensing event and at least one of the completion of the dispensing event and the completion of the retraction movement.

26. 23. The device of claim 22, wherein the drive mechanism is adapted to axially drive the drug container in a distal direction and the retraction mechanism is adapted to axially drive the drug container in a proximal direction.

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