Patent Description:
Diabetes mellitus ("diabetes") is a metabolic disease associated with high blood sugar due to insufficient production or use of insulin by the body. Diabetes affects hundreds of millions of people and is among the leading causes of death globally. Diabetes has been categorized into three types: type <NUM>, type <NUM>, and gestational diabetes. Type <NUM> diabetes is associated with the body's failure to produce sufficient levels of insulin for cells to uptake glucose. Type <NUM> diabetes is associated with insulin resistance, in which cells fail to use insulin properly. Gestational diabetes can occur during pregnancy when a pregnant woman develops a high blood glucose level. Gestational diabetes often resolves after pregnancy; however, in some cases, gestational diabetes develops into type <NUM> diabetes.

Various diseases and medical conditions, such as diabetes, require a user to self-administer doses of medicine. When administering a liquid medicine by injection, for example, the appropriate dose amount is set and then dispensed by the user, e.g., using a syringe, a medicine delivery pen, or a pump. Regardless of the particular device utilized for injecting the liquid medicine, it is important to accurately track the medicine dosed, particularly for managing lifelong or chronic conditions like diabetes. <CIT> is related to a drug delivery assembly for cartridge-based medicaments. <CIT> is related to an electric injector for injecting a medicinal product. <CIT> is related to intelligent medication delivery systems and methods for dose setting and dispensing monitoring.

Provided in accordance with aspects of the present disclosure is a medicine injection pen including a body, a drive member, a rotary encoder, and a gear set. The drive member is disposed within the body and configured to rotate in a first rotational direction relative to the body from a first position to a second position to dispense liquid medicine. The drive member is configured to rotate in a second rotational direction from the second position to the first position to reset the drive member. The rotary encoder includes a first part rotationally fixed relative to the body, and a second part configured to rotate with movement of the drive member to enable determination of an amount of liquid medicine dispensed based on a rotation of the second part relative to the first part. The gear set is operably coupled to the second part of the rotary encoder. The second part is configured to rotate freely relative to the gear set during movement of the drive member in the first rotational direction and to engage the gear set during movement of the drive member in the second rotational direction.

In aspects, the gear set may be a planetary gear set and includes a sun gear and a plurality of planet gears in meshing engagement with the sun gear. The second part may be configured to rotate about the sun gear with the planet gears in the second rotational direction.

In aspects, the sun gear may be configured to rotate with the drive member in the second rotational direction as the drive member moves from the second position to the first position.

In aspects, the second part of the rotary encoder may be configured to rotate with the drive member in the first rotational direction at the same rate as the drive member as the drive member moves from the first position to the second position. The second part may be configured to rotate with the planet gears via the sun gear in the second rotational direction at a lesser rate than the drive member as the drive member moves from the second position to the first position.

In aspects, the drive member and the second part may be configured to be rotated by a motor.

In aspects, the medicine injection pen may further include a processor in communication with the motor. The processor may be configured to automatically control the motor to rotate the drive member in the second rotational direction upon the drive member moving to a predetermined position.

In aspects, the drive member may be a drive screw configured to rotate and translate relative to the body to urge a piston to slide to dispense the liquid medicine.

In aspects, the rotary encoder may be configured to sense rotation of the drive screw to enable determination of the amount of the liquid medicine dispensed.

In aspects, the medicine injection pen may further include an electronics unit configured to determine the amount of the liquid medicine dispensed based on the sensed rotation.

In aspects, the medicine injection pen may further include a cartridge housing releasably engageable with the body and configured to retain a medicine cartridge therein. The medicine cartridge may be configured to retain the liquid medicine therein. The medicine cartridge may include a piston configured to slide within the medicine cartridge. The drive member may be configured to move relative to the body upon actuation thereof to urge the piston to slide within the medicine cartridge to thereby dispense at least some of the liquid medicine through a dispensing end of the medicine cartridge.

In accordance with another aspect of the disclosure, a medicine injection pen is provided and includes a body, a drive member disposed within the body, a rotary encoder, and a gear set. The drive member is configured to rotate in a first rotational direction relative to the body from a first position to a second position to dispense liquid medicine. The drive member is configured to rotate in a second rotational direction from the second position to the first position to reset the drive member. The rotary encoder includes a first part rotationally fixed relative to the body, and a second part configured to rotate with movement of the drive member to enable determination of an amount of liquid medicine dispensed based on a rotational orientation of the second part relative to the first part. The gear set is operably coupled to the second part of the rotary encoder. The second part of the rotary encoder is configured to rotate with the drive member in the first rotational direction at the same rate as the drive member as the drive member moves from the first position to the second position. The second part is configured to rotate with the gear set in the second rotational direction at a lesser rate than the drive member as the drive member moves from the second position to the first position.

Further disclosed herein is a medicine injection pen that includes a rotatable drive member and a rotary encoder associated with the drive member, wherein the rotary encoder is configured to determine an amount of liquid medicine dispensed based on a rotational orientation of the drive member.

<FIG> illustrates a medicine administration and tracking system <NUM> provided in accordance with the present disclosure including a medicine injection pen <NUM> in wireless communication with a computing device <NUM> running a health management application <NUM> associated with pen <NUM> and/or other devices part of or connected to system <NUM>. System <NUM>, in aspects, further includes a data processing system <NUM> and/or a sensor device <NUM>. While the reusable injection pens with replaceable cartridges of the present disclosure are detailed herein configured for use as medicine injection pen <NUM> of system <NUM> with respect to diabetes management, it is understood that the reusable injection pens of the present disclosure are also applicable to management of other diseases and medical conditions and/or for use with other medicine administration and tracking systems.

Medicine injection pen <NUM>, described in greater detail below, is a reusable injection pen configured to removably receive a medicine cartridge, e.g., a cartridge of insulin, for injecting a selected dose of insulin into a patient and recording information concerning the injected dose of insulin, e.g., a dose amount and/or timestamp data associated with the dose.

Computing device <NUM> is detailed and illustrated herein as a smartphone, although any other suitable computing device may be provided such as, for example, a tablet, a wearable computing device (e.g., a smart watch, smart glasses, etc.), a laptop and/or desktop computer, a smart television, a network-based server computer, etc..

Health management application <NUM> is paired with pen <NUM>, which may be a prescription-only medical device, via smartphone <NUM>, although other suitable configurations are also contemplated. In aspects, the pairing of smartphone <NUM> with pen <NUM> at least partially unlocks health management application <NUM> to enable the user to utilize some or all features of health management application <NUM>, e.g., according to the user's prescription. Thus, the act of pairing can unlock and enable the functionality of health management application <NUM> and/or system <NUM> (including pen <NUM>), while health management application <NUM> (and/or system <NUM>) may provide only limited features in the absence of pairing with pen <NUM>.

Health management application <NUM> of smartphone <NUM>, in aspects, can monitor and/or control functionalities of pen <NUM> and provide a dose calculator module and/or decision support module that can calculate and recommend a dose of medicine for the user to administer using pen <NUM>. Health management application <NUM> provides a user interface, on the user interface of smartphone <NUM>, to allow a user to manage health-related data. For example, health management application <NUM> can be configured to control some functionalities of pen <NUM> and/or to provide an interactive user interface to allow a user to manage settings of pen <NUM> and/or settings for smartphone <NUM> that can affect the functionality of system <NUM> (<FIG>). Smartphone <NUM> can additionally or alternatively be used to obtain, process, and/or display contextual data that can be used to relate to the health condition of the user, including the condition for which pen <NUM> is used to treat. For example, smartphone <NUM> may be operable to track the location of the user; physical activity of the user including step count, movement distance and/or intensity, estimated calories burned, and/or activity duration; and/or interaction pattern of the user with smartphone <NUM>. In aspects, health management application <NUM> can aggregate and process the contextual data to generate decision support outputs, e.g., on the user interface, to guide and aid the user in monitoring their condition, using pen <NUM>, and/or managing their behavior to promote treatment and better health outcomes.

In aspects, system <NUM> further includes a data processing system <NUM> in communication with pen <NUM> and/or smartphone <NUM>. Data processing system <NUM> can include one or more computing devices in a computer system and/or communication network accessible via the internet, e.g., including servers and/or databases in the cloud. System <NUM> can additionally or alternatively include sensor device <NUM> to monitor one or more health metrics and/or physiological parameters of the user. Examples of health metric and physiological parameter data monitored by sensor device <NUM> include analytes (e.g., glucose), heart rate, blood pressure, user movement, temperature, etc. Sensor device <NUM> may be a wearable sensor device such as a continuous glucose monitor (CGM) to obtain transcutaneous or blood glucose measurements that are processed to produce continuous glucose values. For example, the CGM can include a glucose processing module implemented on a stand-alone display device and/or implemented on smartphone <NUM>, which processes, stores, and displays the continuous glucose values for the user. Such continuous glucose values can be utilized by health management application <NUM>, for example, for displaying health data, in dose calculation and/or decision support, etc..

With reference to <FIG>, pen <NUM> includes a cap <NUM> configured to protect a medicine dispensing element (e.g., a needle <NUM>) and a body <NUM> configured to contain a replaceable medicine cartridge <NUM>, e.g., an insulin cartridge. Pen <NUM> further includes a dose dispensing mechanism <NUM> to dispense (e.g., deliver) medicine contained in medicine cartridge <NUM> out of pen <NUM> (e.g., through needle <NUM>); a dose setting mechanism <NUM> to enable the selection and/or setting of a dose of medicine to be dispensed; an operations monitoring mechanism <NUM> (e.g., including one or more switches, sensors (electrical, optical, acoustic, magnetic, etc.), encoders, etc.) to qualitatively determine that pen <NUM> is being operated and/or to monitor the operation of pen <NUM> (e.g., to quantitatively determine an amount of medicine set and/or dosed); and an electronics unit <NUM> that can include a processor, a memory, a transceiver, and a battery or other suitable power source.

In aspects, in order to operate pen <NUM>, the user first sets e.g., dials, a dose using a dose knob 26a of dose setting mechanism <NUM>. For example, the dose may be adjusted up or down to achieve a desired dose amount prior to administration of the dose by rotating dose knob 26a in an appropriate direction. Once the appropriate dose has been set, the user applies a force against a dose dispensing button 26b of dose setting mechanism <NUM> to begin dispensing. More specifically, to begin dispensing, the user presses against the portion of dose dispensing button 26b that protrudes from body <NUM> of pen <NUM> to thereby drive a driving element 26c, e.g., a drive screw 26c, of dose dispensing mechanism <NUM> against an abutment, e.g., piston 23b (<FIG>), of medicine cartridge <NUM> to dispense an amount of medicine from cartridge <NUM> through needle <NUM> into the user in accordance with the dose amount set by dose setting mechanism <NUM>, e.g., dose knob 26a, during setting.

Operations monitoring mechanism <NUM> of pen <NUM> senses movement of a rotating and/or translating driving component (e.g., drive screw 26c (see also <FIG>)) of dose dispensing mechanism <NUM>. Operations monitoring mechanism <NUM> may include one or more switches, sensors, and/or encoders for this purpose. More specifically, any suitable switch(es), sensor(s), and/or encoder(s) may be utilized to sense rotary and/or linear movement. Nonlimiting examples of such include rotary and linear encoders, Hall effect and other magnetic-based sensors, linearly variable displacement transducers, optical sensors, etc. With respect to an encoder, for example, the encoder can be configured to sense the rotation of drive screw 26c (<FIG>) that, in turn, translates to dispense medicine; thus, by sensing rotation of drive screw 26c (<FIG>), the translational movement of drive screw 26c can be readily determined. Movement of the encoder may be detected as data processed by the processor of electronics unit <NUM> of pen <NUM>, from which the amount of medicine dosed can be determined.

In aspects, the processor of electronics unit <NUM> of pen <NUM> can store the dose along with a timestamp for that dose and/or any other information associated with the dose. In aspects, the transceiver of electronics unit <NUM> enables pen <NUM> to transmit the dose and related information to smartphone <NUM>. In such aspects, once the dose is transmitted, the dose data and any related information associated with that particular transmitted dose is marked in the memory of electronics unit <NUM> of pen <NUM> as transmitted. If the dose is not yet transmitted to smartphone <NUM> such as, for example, because no connection between the pen <NUM> and smartphone <NUM> is available, then the dose and associated data can be saved and transmitted the next time a successful communication link between pen <NUM> and smartphone <NUM> is established.

The timestamp may be the current time or a time from a count-up timer. When the dose and associated information is communicated to health management application <NUM> running on smartphone <NUM>, the timestamp and/or "time-since-dose" parameter (as determined by the count-up timer) is transmitted by pen <NUM> and received by smartphone <NUM> for storage in memory <NUM> of data processing unit <NUM> of the smartphone <NUM> (see <FIG>). Where a count-up timer is utilized, the time of the dose can be determined without pen <NUM> having to know the current time, which can simplify operation and setup of pen <NUM>. That is, health management application <NUM> can determined the time of dose based on the current time and the value returned from the count-up timer.

Dose dispensing mechanism <NUM> of pen <NUM> can include a manually powered mechanism, a motorized mechanism, or an assisted mechanism (e.g., a mechanism that operates partly on manual power and partly on motorized power). Regardless of the particular configuration of the dose dispensing mechanism <NUM>, as noted above, when a force (e.g., a manual force, electrically-powered motor force, or combinations thereof) is applied to drive screw 26c of dose dispensing mechanism <NUM>, drive screw 26c in turn provides a force to urge medicine from medicine cartridge <NUM> to deliver the set or dialed dose. In aspects, dose dispensing mechanism <NUM> can be operated such that rotation and/or translation of the driving element, e.g., drive screw 26c, is facilitated by a variable tension spring or a variable speed motor to inject the dose over a specific time frame (e.g., <NUM>, <NUM>, etc.) to help reduce the pain of dosing and/or for other purposes.

<FIG> illustrates smartphone <NUM> of system <NUM> (<FIG>) including a data processing unit <NUM>, a wireless communications unit <NUM>, and a display unit <NUM>. Data processing unit <NUM> includes a processor <NUM> to process data, a memory <NUM> in communication with the processor <NUM> to store data, and an input/output unit (I/O) <NUM> to interface processor <NUM> and/or memory <NUM> to other modules, units, and/or devices of smartphone <NUM> and/or external devices. Processor <NUM> can include a central processing unit (CPU) or a microcontroller unit (MCU). Memory <NUM> can include and store processor-executable code, which when executed by processor <NUM>, configures the data processing unit <NUM> to perform various operations, e.g., such as receiving information, commands, and/or data, processing information and data, and transmitting or providing information/data to another device. In aspects, data processing unit <NUM> can transmit raw or processed data to data processing system <NUM> (<FIG>). To support various functions of data processing unit <NUM>, memory <NUM> can store information and data, such as instructions, software, values, images, and other data processed or referenced by processor <NUM>. For example, various types of Random Access Memory (RAM) devices, Read Only Memory (ROM) devices, Flash Memory devices, and other suitable storage media can be used to implement storage functions of memory <NUM>. I/O <NUM> of data processing unit <NUM> can interface data processing unit <NUM> with wireless communications unit <NUM> to utilize various types of wired or wireless interfaces compatible with typical data communication standards, for example, which can be used in communications of data processing unit <NUM> with other devices such as pen <NUM>, via a wireless transmitter/receiver (Tx/Rx), e.g., including, but not limited to, Bluetooth, Bluetooth low energy, Zigbee, IEEE <NUM>, Wireless Local Area Network (WLAN), Wireless Personal Area Network (WPAN), Wireless Wide Area Network (WWAN), WiMAX, IEEE <NUM> (Worldwide Interoperability for Microwave Access (WiMAX)), <NUM>/<NUM>/LTE cellular communication methods, NFC (Near Field Communication), and parallel interfaces. I/O <NUM> of data processing unit <NUM> can also interface with other external interfaces, sources of data storage, and/or visual or audio display devices, etc. to retrieve and transfer data and information that can be processed by processor <NUM>, stored in memory <NUM>, and/or exhibited on an output unit of smartphone <NUM> and/or an external device. For example, display unit <NUM> of smartphone <NUM> can be configured to be in data communication with data processing unit <NUM>, e.g., via I/O <NUM>, to provide a visual display, an audio display, and/or other sensory display that produces the user interface of the health management application <NUM> (<FIG>). In some examples, display unit <NUM> can include various types of screen displays, speakers, or printing interfaces, e.g., including but not limited to, light emitting diode (LED), or liquid crystal display (LCD) monitor or screen, cathode ray tube (CRT) as a visual display; audio signal transducer apparatuses as an audio display; and/or toner, liquid inkjet, solid ink, dye sublimation, inkless (e.g., such as thermal or UV) printing apparatuses, etc..

Once smartphone <NUM> receives the dose and related information (e.g., which can include time information, dose setting, and/or dose dispensing information, and other information about pen <NUM> and/or the environment as it relates to a dosing event), smartphone <NUM> stores the dose related information in memory <NUM>, e.g., which can be included among a list of doses or dosing events. In aspects, via the user interface associated with health management application <NUM>, smartphone <NUM> allows the user to browse a list of previous doses, to view an estimate of current medicine active in the patient's body (medicine on board, e.g., insulin on boar) based on calculations performed by health management application <NUM>, and/or to utilize a dose calculation module to assist the patient regarding dose setting information on the size of the next dose(s) to be delivered. For example, the patient may enter carbohydrates to be eaten and current blood sugar (which alternatively may be obtained directly from sensor device <NUM> (<FIG>)), and health management application <NUM> may already know insulin on board. Using these parameters, a suggested medicine dose (e.g., a recommended insulin dose), calculated by the dose determination module, may be determined. In aspects, smartphone <NUM> can also allow the user to manually enter dose data, e.g., boluses, which may be useful if the battery in pen <NUM> has been depleted or another medicine delivery device, e.g., a syringe, was utilized to dose.

Referring to <FIG> and <FIG>, pen <NUM> and, in particular, the mechanical and hardware features thereof, is detailed, although other mechanical and hardware configurations of pen <NUM> are also contemplated. Pen <NUM> is shown configured as a reusable device for use with replaceable medicine cartridge <NUM> which, once emptied, can be replaced with another medicine cartridge <NUM> or refilled and reinstalled for subsequent use. Medicine cartridge <NUM> includes a vial body 23a defining an interior volume retaining a volume of medicine, e.g., insulin, therein, and a piston 23b sealingly and slidingly disposed within vial body 23a such that displacement of piston 23b within vial body 23a towards the dispensing end of vial body 23a forces medicine from the interior volume through dispensing opening 23c of cartridge <NUM> and into needle <NUM> (<FIG>) for injection into the user. As can be appreciated, the displacement distance of piston 23b is proportional to the amount of medicine dispensed.

Medicine cartridge <NUM> is held within a cartridge housing 23d of pen <NUM> and, in aspects, may be seated within a corresponding cartridge (not shown) positionable within cartridge housing 23d to enable use of various different medicine cartridges (e.g., of different size, shape, etc.) with pen <NUM>. Cartridge housing 23d is releasably engageable with body <NUM> of pen <NUM>, e.g., via threaded engagement, such that, when cartridge housing 23d is disengaged from body <NUM> of pen <NUM>, medicine cartridge <NUM> can be removed and replaced and such that, when cartridge housing 23d is engaged with body <NUM> of pen <NUM> with a medicine cartridge <NUM> therein, medicine cartridge <NUM> is operably positioned relative to dose dispensing mechanism <NUM> of pen <NUM>. However, other suitable configurations enabling removal and replacement of a medicine cartridge <NUM> are also contemplated.

Continuing with reference to <FIG> and <FIG>, dose knob 26a of pen <NUM> may be coupled to body <NUM> of pen <NUM> in threaded engagement via corresponding threads defined on an exterior surface of a portion of dose knob 26a and an interior surface of a portion of body <NUM>. In aspects, electronics unit <NUM> may reside within an electronics housing disposed or defined within dose knob 26a and be coupled thereto via a locking mechanism 26d (e.g., a catch-protrusion mechanism, a clutch, etc.) such that, when dose knob 26a is rotated into or out of body <NUM> to select or adjust the dose to be injected, electronics unit <NUM> remains stationary (e.g., wherein the locking mechanism 26d is in an unlocked state); however, when dispensing button 26b is actuated, locking mechanism 26d is engaged to lock electronics unit <NUM> and dose knob 26a to one another such that electronics unit <NUM> and dose knob 26a rotate together as they translate into body <NUM> upon actuation of dose dispensing mechanism <NUM> to inject the selected dose.

The rotation of the dose knob 26a (and electronics unit <NUM>) during actuation drives (direct or indirect) rotation of drive screw 26c which rides within a nut 26e which is fixed to body <NUM> of pen <NUM>. In this manner, rotation of drive screw 26c also results in translation of drive screw 26c (due to the pitched threading of drive screw 26c) towards medicine cartridge <NUM> to thereby drive piston 23b through vial body 23a to expel medicine from medicine cartridge <NUM> for injection into the user. The extent to which dose knob 26a extends from body <NUM> of pen <NUM> prior to actuation (which corresponds to the selected dose to be injected) defines the maximum amount of rotation of dose knob 26a and, thus, drive screw 26c during actuation; as such, the amount of medicine expelled from medicine cartridge <NUM> during actuation cannot exceed the selected dose amount.

With reference to <FIG>, <FIG>, <FIG>, operations monitoring mechanism <NUM> of pen <NUM> may include a rotary encoder 28a having a first part, such as, for example, an encoder pattern wheel 28b rotationally fixed relative to body <NUM> of pen <NUM>, and a second part, such as, for example, an annular contact plate 28c rotationally fixed relative to drive screw 26c such that relative rotation between the first and second parts 28b, 28c (which, in turn, is indicative of rotation of drive screw 26c relative to body <NUM> during dose dispensing), can be sensed and, thus, from which an amount of medicine dispensed can be determined (due to the proportional relationship between rotation of drive screw 26c and translation of piston 23b). Alternatively or additionally, rotary encoder 28a may be configured to sense the amount of medicine dialed for dosing. Regardless of the particular type of encoder or other sensory components of operations monitoring mechanism <NUM>, relative motion is measured and transmitted to electronics unit <NUM> for processing (e.g., determining an amount of medicine dispensed), storage (e.g., storing in memory the amount of medicine dispensed together with timestamp data) and/or transmission (e.g., transmitting the stored data to smartphone <NUM>).

The encoder pattern wheel 28b may be coupled to the dose dispensing mechanism <NUM> and includes a plurality of segmented contact pads <NUM> arranged in an annular array around the encoder pattern wheel 28b. The encoder pattern wheel 28b further includes three ground pads 231A, 231B, 231C spaced around the inner periphery thereof. The ground pads 231A, 231B, 231C are configured to make ground connections to the annular contact plate 28c via spring connectors 237A, 237B, 237C. For additional details about the encoder pattern wheel 28b, reference may be made to <CIT>.

The annular contact plate 28c includes a ring body <NUM> and an extension or leg <NUM> extending from an outer periphery of the ring body <NUM>. The leg <NUM> of the annular contact plate 28c is configured to electromechanically interface with the segmented contact pads <NUM> during rotation of the annular contact plate 28c during rotation of the screw 26c to enable detection of an amount of relative rotation between annular contact plate 28c and encoder pattern wheel 28b and, thus, an amount of rotation of screw 26c, which corresponds to an amount of medicine dispensed, as detailed above. The annular contact plate 28c of the encoder 28a may be selectively coupled, e.g., via a one-way mechanism as detailed below, to a planetary gear set <NUM>, which includes a ring gear <NUM>, a sun gear <NUM>, a plurality of planet gears <NUM> disposed between the ring gear <NUM> and the sun gear <NUM>, and a carrier plate <NUM> fixed to the planet gears <NUM>. The annular contact plate 28c is configured to be rotated by the carrier plate <NUM> relative to the ring gear <NUM> in only the second rotational direction, as will be described. Due to the gear ratio provided by the planetary gear set <NUM>, manual rotation of the screw 26c to retract the screw 26c and reset the rotary encoder <NUM> is made easier and will occur at a slower rate, such as, for example, about ½ the speed, although other suitable gear ratios and corresponding speed attenuations are also contemplated.

In aspects, the sun gear <NUM> or the screw 26c may be operably coupled to a drive motor, such as, for example, a hollow core electric motor <NUM> (<FIG>) configured to be automatically actuated upon the electronics unit <NUM> sensing that the dose dispensing mechanism <NUM> has fully injected the selected dose, that screw 26c has reached a fully extended position, that cartridge <NUM> is empty, that cartridge <NUM> has been removed and/or replaced, and/or based on any other sensed or input data. The drive motor may retract screw 26c a pre-defined amount, to a pre-defined position, or in any other suitable manner. In aspects, instead of a drive motor, the sun gear <NUM> may be fixed about the screw to rotate with the screw 26c. In use, a user may manually rotate the screw 26c back to a more-retracted or fully-retracted position. Rotation of screw 26c rotates the sun gear <NUM> to, in turn, rotate the annular contact plate 28c in the second rotational direction at a reduced speed such that frictional and other forces associated with rotation of annular contact plate 28c in the second rotational direction are reduced, thus facilitating the user's manual rotation of screw 26c.

With respect to a one-way mechanism, the annular contact plate 28c may include a first set of teeth or pawls <NUM> extending from an inner periphery thereof and a second set of teeth or pawls <NUM> extending from a surface thereof. In aspects, the screw 26c may include a plurality of teeth or a pawl (not shown) configured to engage the first set of pawls <NUM> of the annular contact plate 28c during rotation of the screw 26c in a first rotational direction corresponding to the direction to deploy or extend the screw 26c, e.g., to dispense medicine from cartridge <NUM>. As such, the screw 26c and the annular contact plate 28c rotate with one another at a <NUM>:<NUM> rate of rotation when the screw 26c is rotating in the first rotational direction. When the screw 26c is rotated in the second rotational direction corresponding to the direction of rotation to retract/reset the screw 26c (whether motorized or manually), the screw 26c is free to pass over the pawls <NUM> of the annular contact plate 28c to allow rotation of the screw 26c relative to the annular contact plate 28c. The second set of pawls <NUM> of the annular contact plate 28c are configured to engage surface features <NUM> extending from the carrier plate <NUM> of the planetary gear set <NUM> when the carrier plate <NUM> rotates in the second rotational direction such that the planetary gear set <NUM> is coupled between the screw 26c and the annular contact plate 28c to attenuate the speed of rotation of annular contact plate 28c as compared to the rotational input to back-drive screw 26c.

In operation, the screw 26c is rotated either manually or by the motor in the first rotational direction to move the screw 26c from the first position to the second position during which the screw 26c dispenses liquid medicine from the cartridge <NUM> into a patient. As the screw 26c is moved from the first position to the second position, the annular contact plate 28c rotates therewith and relative to the first part 28b since the first set of pawls <NUM> of the annular contact plate 28c non-rotationally couple the annular contact plate 28c to the screw 26c during rotation of the screw 26c in the first rotational direction.

Upon the screw 26c moving to the second position, the screw 26c is either manually rotated or driven by the motor to rotate the screw 26c in the second rotational direction. Since the sun gear <NUM> of the planetary gear set <NUM> is rotationally fixed to the screw 26c, the sun gear <NUM> rotates with the screw 26c in the second rotational direction. Rotation of the sun gear <NUM> in the second rotational direction causes the planet gears <NUM> to rotate along with the carrier plate <NUM>. The surface features <NUM> of the carrier plate <NUM> engage the second set of pawls <NUM> of the annular contact plate <NUM> to cause the annular contact plate 28c to rotate therewith in the second rotational direction and at a reduced speed.

The various aspects and features disclosed herein may be combined in different combinations than the combinations specifically presented in the description and accompanying drawings.

In one or more examples, the described functional and/or operational aspects may be implemented in hardware, software, firmware, or any combination thereof.

Accordingly, the term "processor" or "processing unit" as used herein may refer to any of the foregoing structure or any other physical structure suitable for implementation of the described techniques.

Claim 1:
A medicine injection pen (<NUM>), comprising:
a body (<NUM>);
a drive member (26c) disposed within the body and configured to rotate in a first rotational direction relative to the body from a first position to a second position to dispense liquid medicine, the drive member configured to rotate in a second rotational direction from the second position to the first position to reset the drive member;
a rotary encoder (28a) including:
a first part (28b) rotationally fixed relative to the body; and
a second part (28c) configured to rotate with movement of the drive member to enable determination of an amount of liquid medicine dispensed based on a rotation of the second part relative to the first part; and
a gear set (<NUM>) operably coupled to the second part of the rotary encoder, wherein the second part is configured to rotate freely relative to the gear set during movement of the drive member in the first rotational direction and to engage the gear set during movement of the drive member in the second rotational direction.