Patent Description:
Medication delivery devices that include a syringe are widely employed by medical professionals and patients who self-medicate. Patients suffering from a number of different diseases frequently must inject themselves with medication and a variety of devices have been developed to facilitate such self-medication. Such devices typically include a syringe having a syringe barrel that holds a medication and a drive system to expel the medication from the syringe barrel through a needle bore into the patient. The device may be an automatic injection device, which includes mechanisms to perform some of the steps of the injection process automatically, rendering it more convenient for a patient to self-medicate. Due to the construction and design of such devices, it is difficult to determine the operational status of the device. While a number of functional medication delivery devices are currently available, improvements in such medication delivery devices remain desirable.

<CIT> discloses an automatic injection apparatus including a delay mechanism for properly delivering medication prior to the needled syringe of the apparatus being retracted. In one form, the delay mechanism includes a shuttle for the syringe, a follower, a locking member, a damping compound between the follower and a supporting surface to dampen rotation of the follower relative to the shuttle, and a dual functioning biasing member acting between the shuttle and the follower. When the locking member moves to a release position during an injection, the dual functioning biasing member first provides a torsional force to force the follower to rotate relative to the shuttle from a latching position to an unlatching position, and then the dual functioning biasing member provides an axial force to force the shuttle axially relative to the follower to move the shuttle for retracting the syringe needle into the housing of the apparatus after injection.

<CIT> discloses an electrical information device and a medicament delivery device. The electrical information device includes at least one start of delivery sensor configured to detect a distal axial movement of a release member of the medicament delivery device. The release member is configured to be distally moved when an activator member of the medicament delivery device is forced distally. The electrical information device also includes at least one information communication unit, which is configured to communicate information related to the medicament delivery. The electrical information device further includes at least one activation unit, which is configured to activate the at least one information communication unit based on a detected distal axial movement of the release member.

<CIT> discloses a manual injection pen suitable for injecting a liquid medication via a non-electrical drive mechanism. The injection pen is provided with a plurality of sensors that senses when a user is taking a specific action with the device.

<CIT> discloses a transponder for determining a characteristic of a dose delivery device. The transponder may include a first sensor configured to detect a first parameter of the dose delivery device based on movement of at least one of the dose delivery device or a medicament contained within the dose delivery device, wherein the first sensor is configured to generate a first signal indicative of the first parameter. The transponder may include a processor operably coupled to the first sensor and configured to process the first signal. The transponder may include an indicator unit operably coupled to the processor and configured to generate an output based on the first signal, wherein the output is perceivable by a user.

The above mentioned and other features of this disclosure, and the manner of attaining them, will become more apparent and the disclosure itself will be better understood by reference to the following description of embodiments of the disclosure taken in conjunction with the accompanying drawings, wherein:.

Corresponding reference characters indicate corresponding parts throughout the several views. Although the exemplification set out herein illustrates an embodiment of the disclosure, in one form, the embodiment disclosed below is not intended to be exhaustive or to be construed as limiting the scope of the disclosure to the precise form disclosed.

The automatic injection apparatus, generally designated <NUM>, has a trigger that when actuated by a user results in the needled syringe of the apparatus automatically being driven downward such that the injection needle projects beyond the bottom end of the apparatus housing to penetrate the user. The apparatus then proceeds to inject automatically the medication contents of the syringe through the needle, after which the syringe is retracted automatically such that the injection needle is returned to within the housing. The delay mechanism of the apparatus helps to stage the operation to ensure that the medication contents are properly delivered prior to the needled syringe being retracted. When a device includes a hidden needle, the user may be provided operational status of the device via an indicator display or lights and/or sounds for each step of the process during the entire cycle of the drug delivery. Furthermore, the recordation and/or communication of drug delivery events or malfunctions may be provided with the device to patients and medical professionals. As used herein, the terms "distal" and "proximal" refer to axial locations relative to a user and opposite to an injection site when the apparatus is oriented for use at such site. For example, proximal end of the housing refers to the housing top end that is farthest to such injection site, and distal end of the housing refers to the housing base or injection end that is closest to such injection site.

An exemplary medication delivery device <NUM> is depicted in <FIG>. Device <NUM> includes a syringe system <NUM>, a drive mechanism, generally designated <NUM>, a retraction mechanism <NUM> and a sensing system <NUM> (depicted in <FIG>) coupled within a device tubular housing <NUM>. The device <NUM> includes a delay mechanism including a shuttle assembly <NUM> to help stage the operation to ensure that the medication contents are properly delivered prior to the needled syringe being retracted. Syringe system <NUM> includes a container barrel body <NUM>, such as made of glass or other suitable material, configured for holding a medication, a slidable piston member <NUM>, such as an elastomeric sealing member, operably coupled with container body <NUM>, and a hollow injection needle <NUM>. The proximal end of injection needle <NUM> is mounted to a distal tip end of the barrel body <NUM>. Injection needle <NUM> is in fluid communication with the medication contents of the syringe barrel body <NUM> and initially coverable by a needle guard <NUM>. Distally advancing piston member <NUM> within barrel body <NUM> toward injection needle <NUM> dispenses medication through needle <NUM>. Drive mechanism <NUM> is operably coupled to the piston member <NUM>. Slidable movement of piston member <NUM> relative to container body <NUM> as a result of operation of the drive mechanism <NUM>, as will be described, dispenses medication from the syringe system <NUM>. The operation of drive mechanism <NUM> and retraction mechanism <NUM> in device <NUM> and other description of the components of an exemplary device are described in <CIT>.

<FIG> illustrates medication delivery device <NUM> in a storage configuration. A syringe overcap <NUM> is secured to housing <NUM> and covers a distal opening <NUM> in housing <NUM>. Needle guard <NUM> is mounted on the distal tip end of barrel body <NUM> of syringe <NUM> to cover needle <NUM>. Overcap <NUM> and needle guard <NUM> protect the user from accidental needle pricks and also protect needle <NUM> from damage. When using device <NUM> to dispense medication, for example, injecting the medication into a patient, overcap <NUM> and needle guard <NUM> are first removed to expose the distal opening <NUM>. <FIG> illustrates device <NUM> after removal of overcap <NUM> and needle guard <NUM> with syringe <NUM> in a storage position and device <NUM> ready for a dispensing event.

Syringe system <NUM> is movable relative to the medication delivery device <NUM> between the storage position, shown in <FIG>, and a delivery position, shown in <FIG> illustrates device <NUM> after the syringe system <NUM> has been moved relative to device <NUM> to a delivery position from its storage position. In the storage position, injection needle <NUM> is at a retracted position within device <NUM> in a manner where the distal tip of needle <NUM> does not extend beyond the distal opening <NUM>. In the delivery position, the distal tip of needle <NUM> projects distally beyond the distal opening <NUM> from device <NUM> at an extended position for operable insertion into a patient.

Drive mechanism <NUM> includes a plunger <NUM> for an engagement relationship with piston member <NUM>. Drive mechanism <NUM> includes a drive spring <NUM> that when released drives plunger <NUM> in a translational distal movement. In an example, spring <NUM> advances plunger <NUM> along a linear path defined by the central axis <NUM> of device <NUM>. Plunger <NUM> includes a distal region with a disc-shaped foot <NUM> (<FIG>) at one end that serves to operationally abut sealing piston <NUM> during plunger advancement. As the plunger <NUM> is further advanced, syringe <NUM> is advanced along axis <NUM> from its storage position to its delivery position. Drive spring <NUM> directly biases the plunger <NUM> downward to drive it and thereby piston <NUM> distally, which driven motion shifts syringe <NUM> distally relative to the shuttle assembly <NUM> and the housing <NUM> to cause the tip of needle <NUM> to project beyond housing distal end for penetrating a user's skin, and then forces the medication contents of the syringe through that needle for an injection. After advancement of syringe <NUM> to its delivery position, the continued advancement of plunger <NUM> advances piston <NUM> within barrel <NUM> to cause medication to be dispensed from needle <NUM> in a dispensing event. The advancement of plunger <NUM> will generally not result in the dispensing of medication from syringe <NUM> until after syringe <NUM> has been advanced to the delivery position. Two main factors inhibit the medication from being dispensed before the syringe is advanced to the delivery position for dispensing. First, is the friction between piston <NUM> and barrel <NUM>. Typically, piston <NUM> will be formed out of a rubber material and barrel <NUM> will be glass. The frictional resistance between these two components may be sufficient to prevent the advancement of piston <NUM> within barrel <NUM> until syringe <NUM> is advanced to its delivery position and engagement with a suitable stop member prevents the further advancement of syringe <NUM>. Additionally, the medication within the syringe may be somewhat viscous and thereby somewhat resistant to flowing out of needle <NUM>. If necessary, modification of the piston member <NUM> and container body <NUM> to alter the frictional resistance of the piston member <NUM> relative to container body <NUM> can limit or prevent the premature dispensing of medication before syringe <NUM> reaches its delivery position.

At the top or proximal end of the housing <NUM> and protruding axially therefrom, a safety-controlled button <NUM> that is part of the user-operated trigger is provided. When a safety sleeve of the housing is disposed in a proper angular orientation relative to the housing <NUM> as rotatably adjusted by the user, button <NUM> is unlocked and can be depressed to start the automatic injection function of the apparatus. To activate drive mechanism <NUM>, a person will depress actuating button <NUM> at the proximal end of device <NUM>. Depressing button <NUM> disengages one or more elongate prongs <NUM> of plunger <NUM> from a shuttle assembly <NUM> thereby allowing spring <NUM> to axially advance plunger <NUM>. Spring <NUM> has a helical shape and surrounds prongs <NUM>. The distal end of spring <NUM> biasingly engages a flange <NUM> on plunger <NUM>.

<FIG> illustrates an example of plunger <NUM>. The proximal region of the plunger includes one or more prongs (a pair of prongs <NUM> shown). The prongs <NUM> are configured to flex radially inward. In another example, the plunger includes a single prong. The foot <NUM> is located along a distal end of the plunger. Ramped surfaces <NUM> may be formed along the tips of the prongs. An outrigger <NUM> distally depends from flange <NUM> of plunger <NUM> in a spaced relationship from the plunger body. Outrigger <NUM> during an injection directly engages a locking member to unlock a rotary member <NUM> of the delay mechanism (depicted in <FIG>). Rotary member <NUM> is also be a part of the retraction mechanism <NUM>. The location of the outrigger <NUM> relative to plunger <NUM> and to the rotary member <NUM> is such that engagement between the outrigger and the rotary member corresponds to the completion of the dispensing event. Depressing button <NUM> causes tabs on button <NUM> to engage ramps <NUM> on prongs <NUM> to bias prongs <NUM> inwardly to disengage prongs <NUM> from an upper shuttle member <NUM> (depicted in <FIG>) of shuttle assembly <NUM> (depicted in <FIG>) to correspond to an initiation of the dispensing event. After prongs <NUM> have been disengaged, spring <NUM> exerts a biasing force on flange <NUM> to advance plunger <NUM> from the first position shown in <FIG> where the piston is at a proximal end of the container barrel body <NUM> to the final fully extended position shown in <FIG> where the piston is at a distal end of the container barrel body <NUM>.

The delay mechanism of device <NUM> includes the shuttle assembly <NUM> (labeled in <FIG>), rotary member <NUM> (labeled in <FIG>) that releasably latches with the shuttle assembly <NUM>, and a spring <NUM> (labeled in <FIG>) acting between the shuttle and the rotary member. The shuttle assembly <NUM> may be formed of a single piece shuttle. In the shown embodiment, shuttle assembly <NUM> is formed of an upper shuttle <NUM> and a lower shuttle <NUM> further shown in <FIG> and <FIG>, respectively. Shuttle parts <NUM> and <NUM> may be fixedly connected during manufacturing assembly, such as with a snap fit or other suitable connection manner, to together serve as the shuttle assembly. The multi-piece construction facilitates molding and assembly of the shuttle, as well as the assembly of the apparatus components within the interior hollow of the shuttle. Suitable materials for any one of the shuttle parts is a plastic such as, for example, polycarbonate or alloy thereof that is transparent.

In the final assembly, upper shuttle member <NUM> captures button <NUM> and spring <NUM> limiting the axial movement of these parts in the proximal direction. The upper and lower shuttle members <NUM>, <NUM> each includes a tubular, cylindrical body. A central aperture <NUM> extends through the upper and lower shuttle member bodies to allow passage of the latching portion of plunger prongs <NUM>. Guide features, such as dogs, project proximally from the upper surface of upper shuttle member <NUM> around aperture <NUM> and help guide activating tabs of button <NUM> into aperture <NUM> during use. Prongs <NUM> engage upper surfaces of upper shuttle <NUM> when the device is in the condition shown in <FIG> and <FIG>. Depressing button <NUM> distally moves tabs of button <NUM> to engage ramps <NUM> on prongs <NUM> to bias prongs <NUM> inwardly to disengage prongs <NUM> from upper shuttle member <NUM>. After prongs <NUM> have been disengaged and positioned within the cross-sectional area of the aperture <NUM>, spring <NUM> exerts a biasing force on flange <NUM> to advance plunger <NUM> from the first position shown in <FIG> to the second position shown in <FIG>. As plunger <NUM> is advanced, syringe <NUM> is advanced to the delivery position and then the piston <NUM> is distally advanced within syringe <NUM> to dispense medication as discussed above.

After the dispensing event is complete, retraction mechanism <NUM> is configured to proximally move syringe <NUM> from the delivery position shown in <FIG> back to the storage position shown in <FIG> or a more proximal position such that the housing covers the needle. In the illustrated embodiment, the retraction mechanism having the delay mechanism includes the spring <NUM>, a syringe carrier <NUM> shown in <FIG> and the rotary member <NUM> that acts as a follower.

Outrigger <NUM> of plunger <NUM> unlocks rotary member <NUM> as plunger <NUM> nears the end of its travel in the distal direction. With additional reference to <FIG>, rotary member <NUM> is rotationally secured to lower shuttle member <NUM> by engagement between latch <NUM> and a latching recess in lower shuttle member <NUM>. Outrigger <NUM> unlocks member <NUM> by depressing latch <NUM>. Spring <NUM> is torsionally preloaded and has a distal end engaged with rotary member <NUM> and an opposite proximal end engaged with shuttle assembly <NUM>. Upon depression of latch <NUM>, spring <NUM> causes rotary member <NUM> to rotate. Member <NUM> includes a slot <NUM> (shown in <FIG>) that receives a tab <NUM> of lower shuttle member <NUM> (shown in <FIG>). At one end of circumferential slot <NUM> formed in the body of the rotary member <NUM>, an axially extending channel <NUM> is defined in the rotary member body. Relative rotation between rotating member <NUM> and lower shuttle member <NUM>, moves tab <NUM> moves within slot <NUM> until tab <NUM> reaches axially extending channel <NUM>. At this position, the biasing spring <NUM> urges axial separation between the rotary member <NUM> and the lower shuttle member.

Member <NUM> is rotatable within housing <NUM> about the axis <NUM> but is axially fixed relative to housing <NUM> and the shuttle assembly <NUM>. An outer radial flange <NUM> defined along a body section of rotary member <NUM> is configured to engage an inner ledge defined along the interior surface of housing member <NUM> to limit the axial movement of member <NUM>. Spring <NUM> exerts an axial force and/or torsional force on member <NUM> to bias member <NUM> distally to thereby maintain member <NUM> in an axial position where flange <NUM> engages the interior ledge of housing member <NUM>. Shuttle assembly <NUM> includes axially extending channels and/or ribs that engage corresponding guiding features defined along the interior of housing member <NUM> that allow shuttle assembly <NUM> to move axially within housing <NUM> and inhibit the relative rotation between shuttle assembly <NUM> and housing member <NUM>.

Spring <NUM> is also axially preloaded and exerts a proximally directed biasing force on shuttle assembly <NUM>. Rotation of rotary member <NUM> about lower shuttle member <NUM> is driven by spring <NUM> until channel <NUM> align with shuttle tabs <NUM>, respectively. In this arrangement, tabs <NUM> are clear of ledges that form slot <NUM> such that shuttle assembly <NUM> and rotary member <NUM> are unlatched. When tab <NUM> reaches channel <NUM>, spring <NUM> moves shuttle assembly <NUM> proximally within housing <NUM> as tab <NUM> slides axially through channel <NUM>. A damping compound may be arranged adjacent rotary member <NUM> to control, such as slowing, the rotation of member <NUM> and allow for the completion of the dispensing event before tab <NUM> reaches channel <NUM>. In the illustrated embodiment, rotary member <NUM> includes a skirt with a plurality of axially extending tabs <NUM> extending below the ledge <NUM>, which are disposed in a grease collar to provide damping.

As shuttle assembly <NUM> moves proximally, it carries syringe <NUM> proximally and moves it back to the storage position shown in <FIG>. Spring <NUM> biases the retraction mechanism <NUM> proximally and thereby maintains syringe <NUM> in its storage position after a dispensing event. A locking mechanism such as a detent on the shuttle assembly <NUM> and a recess on the housing member <NUM> may additionally provide a locking engagement to secure syringe <NUM> in the storage position after a dispensing event whereby the user can then dispose or otherwise handle device <NUM> in a safe manner.

Syringe carrier <NUM> is shown in <FIG>. Arcuate arms <NUM> grip barrel <NUM> of syringe <NUM>. Syringe carrier <NUM> also includes a radial flange <NUM> spaced above the arms <NUM> from a circumferential base. A flange on the syringe barrel <NUM> is captured between arms <NUM> and flange <NUM>. A portion of the underside <NUM> of flange <NUM> engages small flange <NUM> on plunger <NUM> and thereby prevents proximal axial movement of syringe <NUM> before plunger <NUM> is advanced. When shuttle assembly <NUM> is being retracted, lower shuttle member <NUM> engages arms <NUM> to carry syringe <NUM> proximally back to its storage position.

Sensing system <NUM> is operable to detect and/or display or indicate operational status steps to a user or other person. In one example, the sensing system <NUM> includes a sensor for detecting an initial status of the injection process. In another example, the sensing system <NUM> includes a sensor for detecting intermediate and final status of the injection process. In another example, the sensing system <NUM> includes a sensor for detecting all the above-mentioned statuses of the injection process. In another example, the sensing system <NUM> includes a first sensor for detecting an initial status of the injection process, and a second sensor for detecting intermediate and final status of the injection process. In one example in <FIG>, the first sensor includes an accelerometer <NUM> and the second sensor includes an optical sensor <NUM>. The optical sensor <NUM> includes a light emitter <NUM> and a light sensor <NUM>. In one example, the accelerometer <NUM> is associated with the device housing <NUM> at a location to sense acceleration and/or movement of a relevant component and not interfere with movable components. For example, the accelerometer may be embedded on the device housing <NUM> or otherwise affixed along the interior of the device housing <NUM>. In one example, the optical sensor <NUM> is associated with the device housing <NUM> at a location to sense an encoded pattern of a relevant component and not interfere with movable components. For example, the optical sensor <NUM> may be embedded on the device housing <NUM> or otherwise affixed along the interior of the device housing <NUM>. In another example, the accelerometer <NUM> and the optical sensor <NUM> may be associated with a single control module, such as shown in <FIG>.

Various sensor systems are contemplated herein. In general, the sensor systems comprise one or more sensing components and one or more sensed components. The term "sensing component" refers to any component which is able to detect the relative position of the sensed component. A sensing component includes one or more sensing elements, or "sensors", along with associated electrical components to operate the one or more sensing elements. A "sensed component" is any component for which a sensing component is able to detect the position and/or movement of the sensed component relative to the sensing component. For example, the sensed component may axially move and/or rotate relative to the sensing component, which is able to detect the linear and/or angular position and/or the linear and/or rotational movement of the sensed component. The sensing component may include one or more sensing elements, and the sensed component may include one or more sensed elements. The one or more sensing components of a sensor system is/are able to detect the position or movement of the sensed component(s) and to provide outputs representative of the position(s) or movement(s) of the sensed component(s). A sensor system typically detects a characteristic of a sensed parameter which varies in relationship to the position and/or movement of the one or more sensed elements within a sensed area. The sensed elements extend into or otherwise influence the sensed area in a manner that directly or indirectly affects the characteristic 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). Suitable sensor systems may include the combination of an active component (e.g., powered or connected to a power supply or controller) and a passive component (e.g., that is not powered or connected to a power supply or controller). Either the sensing component or the sensed component may operate as the active component. If one component is operating as an active component, the other component need not operate as an active component and may instead operate as a passive component. Any of a variety of sensing technologies may be incorporated by which the relative positions of two members can be detected. Such technologies may include, for example, technologies based on tactile, optical, inductive or electrical measurements. Such technologies may include the measurement of a sensed parameter associated with a field or electrical parameter, such as an electric/magnetic field. In one form, a magnetic sensor senses the change in a sensed magnetic field as a magnetic component is moved relative to the sensor. In another embodiment, a sensor system may sense characteristics of and/or changes to an electric/magnetic field as an object is positioned within and/or moved through the magnetic field. The alterations of the field change the characteristic of the sensed parameter in relation to the position of the sensed element in the sensed area. In such embodiments the sensed parameter may be a capacitance, conductance, resistance, impedance, voltage, inductance, etc. For example, a magneto-resistive type sensor detects the distortion of an applied magnetic field which results in a characteristic change in the resistance of an element of the sensor. As another example, Hall effect sensors detect changes in voltage resulting from distortions of an applied magnetic field. In one example, the second sensor is a magnetic sensor and the rotary component includes a magnetic property.

In <FIG>, an encoder strip <NUM> is formed along the outer circumferential surface <NUM> of the rotary member <NUM>. In one example, the encoder strip is axially disposed along the exterior body of the rotary member <NUM> between the ledge <NUM> and the slot <NUM>. The encoder strip <NUM> includes a plurality of targets <NUM> disposed circumferentially spaced from one another and recognizable by the optical sensor <NUM> of sensing system <NUM>. For example, targets <NUM> may be formed by discretely recognizable targets using a different color for the targets and the space between the targets. In another example, the targets comprise a continuous gradient of two distinct colors to provide a variable signal. Alternatively, the targets <NUM> may be given a different surface treatment. For example, targets <NUM> could be given a rough surface treatment to scatter light while the spaces between targets <NUM> are smooth and reflective.

Sensor system <NUM> also includes a controller <NUM> having an electronic circuit having a processor <NUM>, clock or timer (not shown) for date/time tracking and stamping, and a storage device (not shown). Data may be stored in the storage device, such as, for example, RAM, PROM, optical storage devices, flash memory devices, hardware storage devices, magnetic storage devices, or any suitable computer-readable storage medium. The data may be accessed and operated upon according to instructions from the processor <NUM>.

The accelerometer <NUM> and optical sensor <NUM> are both electronically connected with controller <NUM> and operably coupled with processor <NUM>. Sensor system <NUM> may optionally include a user interface <NUM>. User interface <NUM> may take the form of an LCD screen or, in a more simplified form, one or more LED lights. System <NUM> also includes a power source <NUM> that powers sensors <NUM>, <NUM>, processor <NUM> and user interface <NUM> if it is present. User interface may be a separate display screen located along the device housing. If device <NUM> is a disposable device designed for a single injection procedure, power source <NUM> may be sized to provide sufficient power only for a single procedure. A rechargeable or easily replaceable power source, such as a rechargeable or disposable battery, may be employed if device <NUM> is intended for multiple uses. In the illustrated embodiment, device <NUM> is a single use, disposable device.

Controller <NUM> may include a communication unit (such as transmitter and/or receiver or transceiver) for communicating with a separate device <NUM> as schematically depicted in <FIG>. The separate device <NUM> may take the form of a smart phone having a user interface <NUM>. The communication unit (not shown) is configured to communicate one-way or two-way with the separate device <NUM> which includes a user interface <NUM> that can communicate the occurrence of these events. In one example, the communication unit includes a low power radio-frequency wireless transceiver utilizing a wireless technology standard for exchanging data, such as for example, based on IEEE <NUM> standards, including, but not limited to, Bluetooth (e.g., Bluetooth Standard, low-energy, and Smart) and Zigbee, the ANT and ANT+ protocols, or near field communication (NFC) using a NFC chip. Other suitable wireless communication protocols such as WI-FI may be used. Although it will generally be most convenient to wirelessly communicate with a separate device, it would also be possible to use a wired connection for such communications. 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, Series Standard-A, Standard-B, Standard-C, Mini-A, Mini-B, Micro-A, or Micro-B connector), serial port connector, a video graphics array (VGA) connector, a D-subminiature connector, a BNC connector, or a mini-DIN connector. Furthermore, the electrical connector may by a male or female connector.

As can be most easily seen in <FIG>, sensor system <NUM> is mounted on housing such that accelerometer <NUM> is disposed on the medication delivery device and can sense motion and velocity of housing <NUM> or a component within housing <NUM>. When spring <NUM> acts on plunger <NUM> after the user depresses actuating button <NUM> to initiate the dispensing event, drive spring <NUM> accelerates plunger <NUM> and syringe in the distal direction until the syringe <NUM> hits an axial stop at its delivery position, abruptly halting any more distal movement. This change in acceleration action generates movement and forces that are sensed by accelerometer <NUM>. The timing of the syringe <NUM> arriving at its delivery position and the movement of piston <NUM> for dispensing the medication through the needle may be predetermined and precise. In other words, the initiation of the dispensing event may be associated with the arrival and abrupt stop of the syringe at its delivery position. The retraction event occurs to move the syringe from its delivery position to its storage position. The upward (proximal) acceleration of the syringe during a retraction event imparts a small acceleration in the opposite direction to the injector body. By detecting and analyzing the timing and magnitude of these features, the initiation of the dispensing event and the initiation and/or completion of the retraction event may be detected, and variations in the syringe advance and retract performance could be detected.

The chart presented in <FIG> provides a simplified representation of the output of sensors <NUM>, <NUM>. Line <NUM> represents the signals generated by accelerometer <NUM>, which are indicative of the sensed acceleration and are communicated to processor <NUM>. Spike <NUM> in the accelerometer signals represents the initiation of a dispensing event when the movement of syringe <NUM> into the delivery position is abruptly halted. The further advancing plunger <NUM> moves piston <NUM> for dispensing medication from syringe <NUM>. As the dispensing event begins, the vibration of housing <NUM> caused by the stopping of syringe <NUM> decreases in magnitude as shown by line <NUM>.

As plunger <NUM> nears the end of its distal advancement, outrigger <NUM> on plunger <NUM> unlocks rotary member <NUM> which then begins to rotate about axis <NUM> as discussed in greater detail above. Optical sensor <NUM> may be positioned to sense rotational movement of rotary member <NUM> by sensing the passage of individual targets <NUM>. Optical sensor <NUM> generates signals indicative of this sensed rotational movement of rotary member <NUM> and communicates these signals to processor <NUM>. Dashed line <NUM> in the chart of <FIG> represents the signals generated by optical sensor <NUM>. Also, when plunger <NUM> unlocks rotary member <NUM> and allows member <NUM> to begin rotating, this initiates the retraction movement of retraction mechanism <NUM>. This retraction movement results in the movement of syringe <NUM> from its delivery position (<FIG>) to its storage position (<FIG>).

As best seen in <FIG>, optical sensor <NUM> is positioned to monitor the rotational movement of member <NUM>. <FIG> represents the position of optical sensor <NUM> relative to member <NUM> at the time when rotational movement of member <NUM> is initially started. Arrow <NUM> shows the direction in which member <NUM> will rotate relative to sensor assembly <NUM>. As member <NUM> rotates, targets <NUM> of encoder strip <NUM> are recognized by optical sensor <NUM> as the individual targets <NUM> rotate past optical sensor <NUM>. <FIG> shows member <NUM> when it has completed its rotational movement and tab <NUM> is aligned with channel <NUM> such that shuttle <NUM> is retracted distally by spring <NUM> and returns syringe <NUM> to its storage position.

Line <NUM> in <FIG> represents the signals communicated by optical sensor <NUM>. In one example, the optical sensor signals are binary signals such that the absence of signal (value <NUM> in <FIG>) indicates that the sensor does not sense a target <NUM> and the communication of a signal (value <NUM> in <FIG>) indicates that the sensor recognizes a target. Thus, line spike portions <NUM> of the sensor signal in <FIG> represent the passage of a target <NUM> past optical sensor <NUM>. In another example, the encoder strip <NUM> may include a continuous gradient from black to white such that the optical sensor signals are variable signals. In an example, the optical sensor <NUM> may configured to communicate an analog value sampled by the controller <NUM> to provide finer grain resolution for rotational position and velocity.

When optical sensor <NUM> first recognizes the passage of a target <NUM> as represented by initiation spike point <NUM> of line <NUM>, this represents when rotary member <NUM> has been unlocked and has just begun to rotate. Thus, this point also corresponds to the completion of the dispensing event. In this regard, it is noted that the completion of the dispensing event may correspond directly with the point in time represented by point <NUM>, or, have a known correlation to this point in time, e.g., the completion of the dispensing event may occur <NUM> seconds after the point in time represented by point <NUM>. In either event, point <NUM> signifies that the retraction movement of retraction mechanism <NUM>, such as rotation of rotary member <NUM>, has begun.

The arc through which member <NUM> must rotate to complete its rotational movement and align channel <NUM> with tab <NUM> is known in advance. Thus, the number of targets <NUM> which must pass by optical sensor <NUM> for member <NUM> to complete its rotational movement can also be known in advance. In the illustrated embodiment, when the fifth target <NUM> is recognized by sensor <NUM>, as indicated by reference numeral <NUM> in <FIG>, rotary member <NUM> will have completed its rotational movement and aligned channel <NUM> with tab <NUM>. Once this occurs, shuttle member <NUM> will be moved proximally and syringe <NUM> will be moved to its storage position to complete the retraction movement. In this regard, it is noted that the completion of the retraction event may correspond directly with the point in time represented by point <NUM>, which may also correspond to a complete end of the operational cycle of the device. Alternatively, the completion of the retraction event may have a known correlation with the point in time represented by point <NUM>, e.g., the completion of the retraction event may occur <NUM> seconds after the point in time represented by point <NUM>.

In the illustrated embodiment, and as discussed above, controller <NUM> is configured to detect initiation of the dispensing event based on the signals generated by accelerometer <NUM>. More specifically, controller <NUM> is configured to determine the initiation of the dispensing event based on spike <NUM> of the signal generated from the accelerometer <NUM>. Controller <NUM> is also configured to determine completion of the dispensing event and completion of the retraction movement based upon the signals generated by optical sensor <NUM>. For example, controller <NUM> is configured to determine the initial recognition of rotary movement based on the initial point <NUM> of the signal line <NUM> as the completion of the dispensing event (either with or without correction). Controller <NUM> is configured to determine the final recognition of rotary movement based on the point <NUM> of the signal line <NUM> as the completion of the retraction event (either with or without correction). In one example, controller <NUM> may also count the number of targets recognized by sensor <NUM> and when the appropriate number of targets has been counted to indicate that member <NUM> has fully completed its rotational motion, controller <NUM> interprets this as the completion of the retraction movement and the successful return of syringe <NUM> to its storage position. Controller <NUM> may be configured to detect end of the dispensing or retraction event based on the signals generated by accelerometer <NUM>, which can be independent to or in addition to the optical sensing signal at point <NUM>. When the needle is retracted under a spring force based on the position of the rotary member <NUM>, the sudden stop of the subassembly within the device when reaching the final retracted position produces a detectable acceleration. More specifically, controller <NUM> is configured to determine the ending event based on a spike or valley (not shown in <FIG> but approximately located at time <NUM> sec) of the signal generated from the accelerometer <NUM>. When using both the accelerometer and the optical sensing to detect end of delivery cycle, the controller <NUM> may compare each of the signals for reliability or redundancy in detecting syringe position or travel malfunction. Other characteristics in the accelerometer <NUM> may be useful in detecting syringe position or travel malfunction. One occurs prior to the syringe <NUM> hitting the hard stop when moving to the extended position. As the drive spring <NUM> initially accelerates the syringe <NUM> forward, a small acceleration is imparted to the injector housing <NUM> and may be detected. Another characteristic occurs when the rotary member <NUM> allows the dual functioning biasing member <NUM> to operate. The upward acceleration of the syringe <NUM> imparts a small acceleration in the opposite direction to the injector housing <NUM>. By controller <NUM> detecting and analyzing the timing and magnitude of these features, the initiation of the dispensing event and the initiation and/or completion of the retraction event may be detected, and variations in the syringe advance and retract performance may be detected and indicated and/or communicated.

The operational status of the device determined from such information may be also communicated to the user. To this end, controller <NUM>, in response to determining steps, is configured to generate an output signal for each of the determined steps for a display or other user feedback indication. For example, sensor system <NUM> may generate a signal indicative of the determined initiation of the dispensing event. Sensor system <NUM> may generate another signal indicative of the determined completion of the dispensing event. Sensor system <NUM> may generate another signal indicative of the determined initiation of the retraction movement. Sensor system <NUM> may also generate another signal indicative of the determined completion of the retraction movement. Any one or combination of these output signals may be communicated to the user interface <NUM> to thereby inform the user of occurrence of the initiation of the dispensing event, the completion of the dispensing event, the initiation of the retraction movement, and/or the completion of the retraction movement. For example, an LCD screen or LED lights on device <NUM> could communicate the occurrence of these events.

In addition to simply recognizing when certain events occur, controller <NUM> may also be configured to analyze the sensor signals to identify malfunctions. In one example, controller <NUM> is configured to monitor the signals from optical sensor <NUM> to ensure that rotary member <NUM> has fully completed its rotation to allow syringe <NUM> to be retracted to the storage position. If rotary member <NUM> does not rotate through a sufficiently large rotational arc (for example, only three of five lines <NUM> of signal line <NUM> in <FIG> are monitored), controller <NUM> may be configured to identify this as a malfunction in the retraction movement. If the signals generated by optical sensor <NUM> indicate that rotary member <NUM> did not fully complete its rotational movement, controller <NUM> may be configured to determine that the medication container was not successfully moved from the delivery position to the storage position in the course of a retraction movement.

Controller <NUM> may also be configured to determine the duration of a dispensing event based upon the time interval between spike <NUM> of the accelerometer signal <NUM> and the initiation point <NUM> of the optical sensor signal <NUM> (or the detection of an acceleration associated with a retraction event, as discussed above). If the duration of the dispensing event is shorter or longer than a predetermined threshold range, the processor may determine such event and flag it as a malfunction. Alternatively, if the duration falls within an acceptable range for the quantity of medication being dispensed, it may be considered to be a successful medication delivery. When a malfunction occurs, the controller <NUM> may be configured to communicate to the user interface for display of a warning or flashing of LEDs (red LEDs). Such event may recorded and communicated to a healthcare professional.

The information obtained from such signals may be recorded in memory along with the time and date of the medication dispensing event. This recorded data may then be communicated to a separate remote device <NUM> (such as, for example, mobile phone, laptop, and/or server database) or a caregiver via a wireless connection and/or the internet. Device <NUM> may keep a log of all such medication delivery events, including the date and time of the medication delivery event and whether or not any malfunctions were detected. Device <NUM> may also communicate such information through a network to a medical professional who may also maintain a log of such medication delivery events. Controller <NUM> may also be configured to record in memory and communicate the type of medication dispensed and the quantity. For single use, disposable devices, this information will be known in advance and the recordation thereby easily facilitates the communication of the type and quantity of the medication being delivered in a delivery event. The ability for a user to automatically generate a log of medication delivery events can be extremely useful for users who regularly inject medication and find it cumbersome or inconvenient to maintain a log of such medication delivery events.

As can be seen in the figures, except for encoder strip <NUM> located on rotary member <NUM>, sensor system <NUM> is packaged in a single small housing mounted on housing <NUM>. As such, it can be permanently mounted on a device <NUM> or detachable and re-used with multiple devices provided that such devices have a rotary member <NUM> with an encoder strip <NUM> and a mounting interface to accept sensor system <NUM>.

In one example, an exemplary method for determining the operational status of the device <NUM> is provided. The method may include determining an initiation of the dispensing event. The controller <NUM> is configured to determine initiation of the dispensing event based on the first signals generated by the first sensor. When the first sensor is an accelerometer, the initial spike in the signal may be due to the abrupt stop of the syringe when it is moved from the storage position to the delivery position. Another step may include determining an end of the dispensing event. The arrangement of the outrigger of the plunger and the rotary follower is such that engagement between the outrigger and the rotary follower and thus the start of rotation of the follower is at the moment when the dispensing event is completed. The controller <NUM> is configured to determine completion of the dispensing event based upon an initial spike of second signals generated by the second sensor. Another step may include determining an end of the retraction and/or complete drug delivery cycle. The controller <NUM> is configured to determine completion of the retraction movement based upon the predetermined spike of second signals generated by the second sensor, or upon detection of an acceleration caused by retraction of the syringe into the device housing. The method may include indicating the determined initiation of the dispensing event, the determined completion of the dispensing event, the determined initiation of the retraction, the determined completion of the retraction or delivery cycle, or any combination thereof. The controller may be further configured to communicate any of the indicated events to an on-board user indicator or to 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 sensor based on the first and/or second signals from the respective sensors, compare such parameters to threshold ranges stored in the storage device, and if outside the threshold range, communicate any determined malfunction to an on-board user indicator or to a remote user indicator external to the device.

Claim 1:
A medication delivery device (<NUM>) comprising:
a housing (<NUM>);
a medication container (<NUM>) having a container body (<NUM>) to hold a medication and a slidable piston (<NUM>) operably coupled with the container body, the slidable piston movable relative to the container body to dispense medication from the medication container, the medication container being movable relative to said housing between a storage position and a delivery position;
a drive mechanism (<NUM>) adapted to, when a dispensing event is initiated, drive the medication container from the storage position to the delivery position; and
a retraction mechanism (<NUM>) adapted to, when a retraction movement is initiated, drive the medication container from the delivery position to the storage position;
characterized in that the device further comprises:
an accelerometer (<NUM>) disposed within the medication delivery device, the accelerometer configured to detect a first acceleration caused by motion of the medication container relative to the housing as the medication container is driven from the storage position to the delivery position by the drive mechanism, and configured to detect a second acceleration caused by motion of the medication container relative to the housing as the medication container is driven from the delivery position to the storage position by the retraction mechanism; and
a controller (<NUM>) operably coupled with the accelerometer, wherein the controller is configured to determine initiation of the dispensing event based on the detected first acceleration, and completion of the retraction movement based on the detected second acceleration.