Patent Description:
One problem sometimes exhibited by prefilled syringes is the unwanted movement of their plungers during transit. Internal/external differential pressure changes due to, for example, changes in temperature or atmospheric pressure, may cause the plunger to move during air shipment and/or travel through different elevations. The movement of the plunger can affect product sterility. Another problem is the invasiveness of other potential solutions. Low cost injection devices, like prefilled syringes, have extremely strict manufacturing standards regarding modifications to the size, shape, and materials of the barrel and syringe plunger.

In an exemplary embodiment of the present disclosure, a syringe system is disclosed. The syringe system having a plunger including a microcontroller, a battery, and a coil connected to the microcontroller and the battery by two or more electrical leads. A syringe barrel has a proximal end, a distal end, and a cylindrical sidewall defining a longitudinal axis, the cylindrical sidewall extending longitudinally between the proximal and distal ends. The sidewall has an exterior surface and defines an internal volume. The plunger is positioned between the proximal and distal ends of the syringe barrel and is movable within the internal volume with respect to the syringe barrel in the longitudinal direction. The syringe barrel further includes a label disposed on the sidewall and formed by at least two conductive strips extending in a non-parallel direction with respect to the longitudinal axis and having unique lengths. The microcontroller is configured to determine a position of the plunger with respect to the syringe barrel by measuring a current induced in the coil by the at least two conductive strips.

In some embodiments of the system, the plunger includes a head section, at least a portion of which extends outside of the syringe barrel, and the battery and the microcontroller are disposed in the head section.

In some embodiments, the system further includes a temperature sensor configured to output a signal representative of a temperature of the syringe system to the microcontroller.

In some embodiments, the system further includes a wireless communication interface. The microcontroller is configured to transmit the temperature data received from the temperature sensor to a smart device via the wireless communication interface.

In some embodiments, the system further includes a wireless communication interface. The microcontroller is configured to transmit plunger position data to an external device via the wireless communication interface.

In some embodiments, the external device is configured to provide an alert to a user if the plunger position is determined by the microcontroller to have moved in excess of a predetermined distance.

In some embodiments, the microcontroller is configured to periodically cause the battery to supply the current to the coil at predetermined intervals.

In some embodiments, the at least two conductive strips are transparent.

In some embodiments, the at least two conductive strips are arranged on the sidewall of the barrel so as to be spaced apart from one another in the longitudinal direction, and are arranged in order according to circumferential length.

In another exemplary embodiment of the present disclosure, a method of using a syringe system is disclosed. The system including a plunger having a microcontroller, a battery, and a coil connected to the microcontroller and battery by two or more electrical leads. The syringe system further includes a syringe barrel defining a longitudinal axis and receiving the plunger, and a label disposed on a sidewall of the syringe barrel and having at least two conductive strips extending in a non-parallel direction with respect to the longitudinal axis and having unique lengths. The method includes generating, by the microcontroller, an eddy current in the coil by causing the battery to supply a current to the coil via the two or more electrical leads. An amplitude of the generated eddy current depends on a relative position of the coil with respect to each of the conductive strips of the label along a longitudinal direction of the syringe barrel. The method further includes measuring, by the microcontroller, the generated eddy current in the coil via the two or more electrical leads, and determining, by the microcontroller based on the measured eddy current, a position of the plunger with respect to the syringe barrel.

In some embodiments, the method can further include transmitting, by the microcontroller via a wireless communication interface, data regarding the determined plunger position to an external device.

In some embodiments, the method can further include generating, by the external device, one or more alerts based on data regarding the plunger position.

In some embodiments, the method can further include generating, by a temperature sensor, temperature data based on a measured temperature of the syringe system; and transmitting, by the microcontroller via a wireless communication interface, the temperature data to an external device.

In some embodiments, the method can further include generating, by the external device, one or more alerts based on the temperature data.

Various aspects of the disclosure will now be described in connection with the attached drawings. For the purpose of illustration, there are shown in the drawings embodiments which are presently preferred. It should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown.

Certain terminology is used in the following description for convenience only and is not limiting. The words "right," "left," "lower," and "upper" designate directions in the drawings to which reference is made. The words "inwardly" and "outwardly" refer to directions toward and away from, respectively, the geometric center of the apparatus and designated parts thereof. The terminology includes the above-listed words, derivatives thereof, and words of similar import. Additionally, the words "a" and "an," as used in the claims and in the corresponding portions of the specification, mean "at least one.

The present disclosure may provide an affordable, scalable method of electrical communication to a drug delivery device, such as a single use syringe system <NUM>, through the use of electrical induction. <FIG> is a block diagram depicting features of the syringe system, in accordance with aspects described herein. The syringe system <NUM> preferably includes at least a plunger <NUM> and a syringe barrel <NUM>. The plunger <NUM> may be manually or automatically operated to apply pressure within the syringe barrel <NUM> such that a medicament (not shown) within the syringe barrel <NUM> can be dispensed through an opening, such as a needle <NUM>. The syringe system <NUM> preferably allows for communication of status information (e.g., completion of an injection, movement of the plunger <NUM>, temperature information, and the like) to an external device <NUM>, such as a smart device, which may include a smart phone, tablet, personal computer, or other digital medical system or the like, through Bluetooth Low Energy or other wireless protocols via a wireless communication interface <NUM>. Information regarding the position of the plunger <NUM> is preferably generated using electrical induction generated in a conductive coil <NUM> wrapped around or within the plunger <NUM>, in conjunction with a microcontroller <NUM>, which, in certain aspects, may be a Cypress PSoC <NUM><NUM>-bit internet-of-things microcontroller or the like, and which is preferably embedded within the plunger <NUM>.

The syringe barrel <NUM> preferably includes a label <NUM> formed thereon or affixed thereto, preferably on an outer surface of the syringe barrel <NUM>. The label <NUM> may be placed on the outer circumference or an inner circumference of the syringe barrel <NUM>, although the label <NUM> may also be embedded within a material of the syringe barrel <NUM>. The label <NUM> preferably includes varying amounts of a conductive substrate running along a length of the label <NUM> in a longitudinal direction of the syringe barrel <NUM>. In a preferred embodiment, the label <NUM> preferably includes a plurality of conductive strips <NUM> (<FIG>), each of which extends in a circumferential direction, which may include a non-parallel direction with respect to a longitudinal axis of the syringe barrel <NUM>, on the sidewall <NUM> of the syringe barrel <NUM>. At least two of the conductive strips <NUM> have unique lengths, and preferably, each of the conductive strips <NUM> has a unique length. In another embodiment not shown, the conductive strips <NUM> may be oriented at an angle. Each of the conductive strips may be oriented at the same angle or at different angles. In these embodiments, each of the conductive strips <NUM> may have a unique effective length, which is the transverse length of the conductive strip <NUM> (i.e., the cosine of the pitch angle with respect to the longitudinal axis multiplied by the overall length of the conductive strip <NUM>). Thus, conductive strips having the same overall length could be arranged at different angles to provide an array of strips each having a unique effective length. In the embodiment shown in <FIG>, the overall length for each strip is the same as the unique effective length thereof. Consequently, as used herein, the term "unique length" will also refer to the unique effective length. The conductive strips <NUM> are preferably spaced apart from one another in the longitudinal direction on the syringe barrel <NUM> and may be arranged in order according to circumferential length (e.g., the longest strip may be adjacent one end of the syringe barrel <NUM> while the shortest strip can be adjacent to the other end). The conductive strips <NUM> may be composed of materials including, but not limited to, carbon, silver, copper ink, or the like. In certain aspects, one or more of the conductive strips <NUM> may be printed using a transparent conductive material. In other embodiments, each of the conductive strips may be comprised of a wire.

In other aspects, the label <NUM> may also be placed on other elements nearby, such as in the case of a syringe accessory, auto injector, or wearable drug delivery device (not shown), if it is in close enough proximity to the conductive coil <NUM> located on the plunger <NUM> to induce eddy currents therein. As described in further detail below, depending on a location of the plunger <NUM> with respect to the syringe barrel <NUM>, and more particularly, a location of the coil <NUM> with respect to the label <NUM>, the microcontroller <NUM> preferably measures a different eddy current produced by electrical induction generated in the coil <NUM> of the plunger <NUM> in part by a combined transverse length of the conductive strips <NUM> present at the particular location of the label <NUM>.

The detected position is preferably written to a memory <NUM> in the plunger <NUM> to record, for example, any unintentional movement of the plunger <NUM> during transport. The memory <NUM> is preferably powerless, but can also be powered by a battery <NUM> (<FIG>) or other power source. The microcontroller <NUM> may also use an embedded temperature sensor <NUM> to detect the temperature of the plunger <NUM>, and may also write this temperature data to the memory <NUM> at a predetermined time interval, which may allow a temperature history of the syringe system <NUM> to be tracked to ensure proper cold chain integrity. In certain aspects, the syringe system <NUM> may alert the user, for example via the external device <NUM>, of deviations from proper storage temperature conditions. This feature may also be used to notify a user that the medicament is at the proper temperature for injection after it has been removed from cold chain storage. Additionally, the detection of the plunger <NUM> positions may allow a user to see when and how much of a dose was administered to help ensure adherence and proper drug dosing.

The use of a microcontroller <NUM> and induction sensor <NUM> in accordance with aspects of the present invention may help reduce the cost of a plunger tracking system compared to some other potential solutions by eliminating the number of components needed, and may also allow for the tracking of the movement of the plunger <NUM> during transport. For example, the low energy microcontroller <NUM> may determine if there has been a change in position of the plunger <NUM> by sampling at predetermined intervals. In certain embodiments, the interval may be one second or shorter. If a change in the position of the plunger <NUM> is detected, the microcontroller <NUM> may start to record data and transmit to the connected smart device <NUM> via the wireless communication interface <NUM>. The smart device <NUM> may alert the user that a change in the position of the plunger <NUM> has been detected.

The syringe system <NUM> may also be able to track and record the temperature thereof, and the length of time since the syringe barrel <NUM> was filled, by using an internal clock (not shown) of the microcontroller <NUM>, as well as the on-board temperature sensor <NUM>, which may be used to measure the temperature at a pre-set interval. The microcontroller <NUM> may write the temperature data to the memory <NUM> during an 'active' duty cycle of the microcontroller <NUM>.

In certain aspects, the electronics used in this disclosure may be low-cost and small enough in scale to use on prefilled syringes and other injection devices. It may also be scaled to fit larger devices. The microcontroller <NUM> may have considerable power savings over previously created systems through the use of ultra-low boot cycles and a considerable 'inactive' duty cycle, which may minimize power drain and idle time.

<FIG> is a perspective view of the plunger <NUM> for use in an embodiment of the syringe system <NUM>. The plunger <NUM> may use the battery <NUM> (such as a CR1220) to provide power to the coil <NUM>, the microcontroller <NUM>, and/or other components thereof. In certain aspects, the battery <NUM> may be rechargeable. The plunger <NUM> may house the battery <NUM> within a head section <NUM> at one end of the plunger <NUM>. The head section <NUM> may also contain the microcontroller <NUM> (not shown in <FIG>), which may be mounted to a printed circuit board <NUM>. A set of two or more electrical leads <NUM> preferably runs from the microcontroller <NUM> in the head section <NUM> through a shaft <NUM> of the plunger <NUM>, to where the leads <NUM> connect and transmit electrical signals to and from the coil <NUM> at a distal end of the plunger <NUM> opposite to the head section <NUM>. The battery <NUM> and microcontroller <NUM> may be located on top of the syringe plunger <NUM> with the electrical leads <NUM> running from the microcontroller <NUM> to the piston <NUM>, which may contain a locking mechanism (not shown) for a medicament delivery system.

In a preferred embodiment, the battery <NUM> periodically supplies current to the coil <NUM> through the electrical leads <NUM>. By supplying current to the coil <NUM>, an electrical induction field is generated at the coil <NUM> that can interact with the conductive strips <NUM> (<FIG>) present on the label <NUM> disposed on the syringe barrel <NUM>, which can be used to induce one or more eddy currents in the coil <NUM>. The amplitude of the eddy current induced in the coil <NUM> depends at least in part on a relative position of the coil <NUM> with respect to each of the conductive strips <NUM> in the label <NUM> along the longitudinal direction of the syringe barrel <NUM> at the time the battery <NUM> supplies the current. The eddy current is influenced by one or more of the conductive strips <NUM> that are closest to the coil <NUM> when the current is applied, and the unique lengths of the conductive strips <NUM> distinguish the magnitude of the eddy current depending on the relative location of the coil <NUM>. The microcontroller <NUM> measures the induced eddy current via the electrical leads <NUM>, and interprets and converts the measurement into data representing a position of the plunger. In some embodiments, the microcontroller <NUM> is configured to periodically cause the battery <NUM> to supply current to the coil <NUM> at predetermined intervals. For example, the battery <NUM> may supply current every second, every five seconds, every minute, or any other interval. The microcontroller <NUM> may, in such embodiments, also determine the plunger position at these same supplying intervals.

<FIG> illustrates a syringe barrel <NUM> for a syringe system <NUM>, in accordance with aspects disclosed herein. In certain embodiments, the syringe barrel <NUM> may have the label <NUM> with one or more conductive strips <NUM> of varying size arrayed in a smallest-to-largest or largest-to-smallest configuration. In certain aspects, the smaller conductive strips <NUM> provide a smaller inductive force on the coil, while the larger conductive strips <NUM> may provide a larger inductive force on the coil. The configuration of metal printing of the label <NUM> may be in several forms, with the configuration shown in <FIG> shown as only one exemplary aspect of the configuration.

The syringe barrel <NUM> has a proximal end and a distal end and a cylindrical sidewall <NUM> extending longitudinally therebetween. The sidewall <NUM> has an exterior surface and defines an internal volume within which medicament may be stored. A barrel opening <NUM> is preferably located at the proximal end of the syringe barrel <NUM> and may be configured to accept medicament containers, such as drug ampules or vials. The plunger <NUM> may also preferably be inserted into the barrel opening <NUM> during manufacture and for transport, with the plunger <NUM> being movable within the internal volume of the syringe barrel <NUM> with respect thereto in the longitudinal direction for dispensing medicament. The medicament may be dispensed through a needle <NUM> or other delivery mechanism at the distal end of the syringe barrel <NUM>.

<FIG> illustrates an assembled syringe system <NUM>, in accordance with aspects described herein. The plunger <NUM> is shown inserted into the syringe barrel <NUM> such that the coil <NUM> interacts with the label <NUM>. Eddy currents generated in the coil <NUM> are communicated over the electrical leads <NUM> to be processed by the microcontroller <NUM> (not shown in <FIG>) housed on the circuit board <NUM> and located in the head portion <NUM> of the plunger <NUM>. In certain aspects, a safety cover <NUM> may be used to cover the needle <NUM> or drug delivery mechanism during transport and before use.

The syringe system <NUM> preferably allows healthcare providers to automatically monitor the state of the low-cost injection device, which enables them to track dosing regimen adherence, shelf-life evaluation, plunger movement during transportation, and cold chain integrity.

The technology may also be implemented into more complex injection devices that already include wireless connectivity. Autoinjectors which utilizes a moving plunger <NUM> and a syringe barrel <NUM> may incorporate features of the disclosure described herein. The syringe barrel <NUM> may be made of materials that do not interfere with the magnetic field created by the coil, such as polymers, ceramics, and some metals. On-body or wearable injectors could also accommodate the technology described herein. In addition, this technology may be particularly relevant for syringes that utilize a safety system.

Further, the syringe system <NUM> may also be used in a hospital environment to communicate automatically with the hospital inventory management system, such that the syringe use may be tracked in real-time and re-ordered automatically based on a pre-set inventory level.

The syringe system <NUM> may be produced by over-molding or insert-molding the microcontroller <NUM>, battery <NUM>, and electrical conductors into the plunger <NUM>, as described throughout this disclosure. This may be done during a general injection molding process.

The label <NUM> may be applied to the syringe barrel <NUM> using any conventional syringe labeling equipment. The piston <NUM> may also contain elements of the electrical system, such as the coil <NUM>, so that when the plunger <NUM> is assembled to the piston <NUM>, it may complete the electrical circuit. In some aspects, some of the electrical components may be contained within a syringe flange adaptor (not shown), or in the surrounding components of an autoinjector or wearable on-body drug delivery system.

Embodiments of the present invention may also be used in a similar fashion with existing self-injection devices, like a prefilled syringe. The movement of the plunger <NUM> and/or temperature of the device may be detected by the microcontroller <NUM>. The microcontroller <NUM> may read and record the information, then may transmit the information to a smart device <NUM> via, for example, BLE communication. The external device <NUM> may have a connected application to read, record, and display the information from the syringe system <NUM>. This information may also be relayed to healthcare providers and other stakeholders.

Claim 1:
A syringe system (<NUM>), comprising:
a plunger (<NUM>) including:
a microcontroller (<NUM>),
a battery (<NUM>), and
a coil (<NUM>) connected to the microcontroller (<NUM>) and the battery (<NUM>);
a syringe barrel (<NUM>) defining a longitudinal axis and having a proximal end, a distal end, and a cylindrical sidewall (<NUM>) that extends longitudinally between the proximal and distal ends, the cylindrical sidewall (<NUM>) having an exterior surface and defining an internal volume, the plunger (<NUM>) being movable within the internal volume with respect to the syringe barrel (<NUM>) along the longitudinal axis; and
characterized in the syringe system (<NUM>) further including a label (<NUM>) having one or more conductive strips (<NUM>) extending in a non-parallel direction with respect to the longitudinal axis,
wherein the microcontroller (<NUM>) is configured to determine a position of the plunger (<NUM>) with respect to the one or more conductive strips (<NUM>) based on a current induced in the coil (<NUM>).