Method and system for selecting an injection site

Abstract

Methods and systems are provided for assessing an injection site on a patient's body. The methods / systems may instruct the patient to place one or more capacitance sensors in contact with a potential injection site on the patient's body. The methods / systems may also include receiving, using a processing circuit, data indicative of capacitance of bodily tissue at the potential injection site as measured by the one or more capacitance sensors. The methods / systems may also include generating, using the processing circuit, an indication of an expected pain level the patient would experience from a potential injection at the potential injection site based on the received capacitance.

Description

[Background technology]

[0001] Injection devices in the form of or including syringes are widely used by medical professionals and patients who self-medicate. Patients suffering from a number of different diseases may frequently inject themselves with medication, and various devices have been developed to facilitate such self-medication. In one example, the use of an automatic injection device that includes mechanisms to perform some of the steps of the injection process makes self-medication more convenient for patients, especially those with limited manual dexterity. The automatic injection device may be a single-use device that is disposed of after use. Summary of the Invention [Problem to be solved by the invention]

[0002] The inventors recognize that using an injection device to perform an injection may potentially cause pain to the patient at the injection site at the time of injection and / or within a few hours (e.g., 1-3 hours) after injection. The inventors also recognize that injections at some injection sites may result in less injection site pain than other injection sites. Which injection sites result in less pain may vary from patient to patient based on the physiology of the patient's body. It is therefore desirable to provide personalized guidance to the user and / or patient as to which injection sites may result in less pain. [Means for solving the problem]

[0003] According to an exemplary embodiment of the present disclosure, a method for evaluating an injection site on a patient's body is provided, the method including receiving, at a processing circuit in communication with one or more capacitance sensors positioned at a potential injection site on the patient's body, a signal indicative of the capacitance of body tissue at the potential injection site as measured by the one or more capacitance sensors, and determining, at the processing circuit, based on the received signal, an expected pain level that the patient will experience from an anticipated injection at the potential injection site.

[0004] According to another embodiment of the present disclosure, a processing device for evaluating an injection site on a patient's body is provided, the device comprising: a memory storing instructions; a communication interface configured to receive data from one or more capacitance sensors via the communication interface; and a processing circuit configured to execute the instructions to receive data from the one or more capacitance sensors via the communication interface indicative of capacitance of body tissue at a potential injection site on the patient's body as measured by the one or more capacitance sensors, store the received data indicative of the capacitance in a memory; and determine an expected pain level that the patient will experience from an anticipated injection at the potential injection site based on the received data indicative of the capacitance.

[0005] According to yet another embodiment of the present disclosure, there is provided a system for assessing an injection site on a patient's body, the system comprising: an injection device comprising a needle for delivering a medication to the patient via injection, one or more capacitance sensors, and a wireless transmitter; and an external device comprising a memory storing instructions, a communications interface configured to receive data from the wireless transmitter of the injection device, and a processing circuit, the processing circuit being configured to execute the instructions to receive, via the communications interface, data from the injection device indicative of capacitance of body tissue at a potential injection site on the patient's body as measured by the one or more capacitance sensors, store the received data indicative of the capacitance in a memory, and determine an expected pain level that the patient will experience from an anticipated injection with the injection device at the potential injection site based on the received data indicative of the capacitance.

[0006] In some embodiments, an exemplary advantage of the disclosed methods and systems is that they provide personalized guidance to a patient as to which injection sites on the patient's body are likely to result in less injection site pain. Other advantages will be recognized by those skilled in the art. [Brief description of the drawings]

[0007] The above and other features and advantages of the present disclosure, and the manner in which they are accomplished, will become more apparent and be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings. [Figure 1] FIG. 1 is a cross-sectional view of an injection device prior to use, according to an exemplary embodiment. [Diagram 2] FIG. 2 is a cross-sectional view of the injection device of FIG. 1 with the syringe assembly in a stored position and ready for an injection event. [Diagram 3] FIG. 2 is a cross-sectional view of the injection device of FIG. 1, with the syringe assembly in the injection position. [Figure 4] FIG. 1 is a system architecture diagram of electrical components within the injection device and an exemplary external computing device. [Diagram 5] FIG. 1 is a perspective view of a lower body support member that supports a printed circuit board (PCB) in the injection device. [Figure 6A] These are top and bottom views, respectively, of the same PCB. [Figure 6B] These are top and bottom views, respectively, of the same PCB. [Figure 7] 1 is a flowchart depicting example logic for assessing an injection site on a patient's body using capacitance data collected by a capacitance sensor. [Figure 8] 13 is a flow chart illustrating exemplary logic for collecting capacitance data and generating insights regarding potential injection site pain. [Figure 9] 13 is a flow chart illustrating exemplary logic for viewing generated insights and recording / logging injection data. [Figure 10A] 13 presents exemplary screenshots displayed on an external computing device. [Figure 10B] 13 presents exemplary screenshots displayed on an external computing device. [Figure 10C] 13 presents exemplary screenshots displayed on an external computing device. [Figure 10D] 13 presents exemplary screenshots displayed on an external computing device. [Figure 10E] 13 presents exemplary screenshots displayed on an external computing device. [Figure 10F] 13 presents exemplary screenshots displayed on an external computing device. [Figure 10G] 13 presents exemplary screenshots displayed on an external computing device. [Figure 10H] 13 presents exemplary screenshots displayed on an external computing device. [Figure 10I] 13 presents exemplary screenshots displayed on an external computing device. [Figure 10J] 13 presents exemplary screenshots displayed on an external computing device. [Figure 10K] 13 presents exemplary screenshots displayed on an external computing device.

[0008] Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set forth herein illustrate exemplary embodiments of the present invention, and such exemplifications should not be construed as limiting the scope of the present invention in any manner. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] In Figures 1-3, a drug injection device 20 is illustrated in various operating states. One example of such a device and its operation is described in U.S. Patent No. 8,734,394 (B2), issued May 27, 2014 to Adams et al., and U.S. Patent Application Publication No. 2021 / 0093784 (A1), published April 1, 2021 to Adams et al., the entire disclosures of each of which are incorporated herein by reference. The device 20 includes a syringe assembly 22, a drive mechanism 24, and a retraction mechanism 26, and may include one or more main printed circuit boards (PCBs) 500, shown, for example, in Figures 5, 6A, and 6B below. The syringe assembly 22 includes a barrel 30 forming a container body for holding the drug, and a piston 32 disposed within the barrel 30 for driving the drug out of the barrel. Syringe assembly 22 also includes a needle assembly 33 having a hollow injection needle 34 and a needle hub 35 that attaches needle 34 to syringe barrel 30. A lower body support member 29 (shown in FIG. 5 ), which is coupled to a device housing 38, surrounds needle 34. Advancing a piston 32 within barrel 30 toward needle 34 causes medication to be dispensed through needle 34.

[0010] The devices described herein, such as device 20, may further include a medicament, such as, for example, in syringe barrel 30. In another embodiment, a system may include one or more devices, including device 20, and a medicament. The term "medicament" refers to one or more therapeutic agents, including but not limited to insulin, insulin analogs such as insulin lispro or insulin glargine, insulin derivatives, GLP-1 receptor agonists such as dulaglutide or liraglutide, glucagon, glucagon analogs, glucagon derivatives, gastric inhibitory polypeptide (GIP), GIP analogs, GIP derivatives, combined GIP / GLP-1 agonists such as tirzepatide, oxyntomodulin analogs, oxyntomodulin derivatives, therapeutic antibodies, including but not limited to IL-23 antibody analogs or derivatives such as mirikizumab, IL-17 antibody analogs or derivatives such as ixekizumab, therapeutic agents for pain-related treatments such as galcanezumab, lasmiditan, and any therapeutic agent that can be delivered by the devices described herein. Agents such as those used in the devices may be formulated with one or more excipients. The device is operated by a user, caregiver, or medical professional in a manner generally as described above to deliver medication to a patient. As used herein, the term "user" may refer to an operator of a device described herein, and the term "patient" may refer to a person receiving a medication. In some cases, the user and the patient may be the same person (e.g., the patient is operating a device described herein to give themselves an injection). In other cases, the user and the patient may be different people (e.g., the user may be a person providing care to the patient).

[0011] FIG. 1 illustrates the device 20 in its initial, pre-use configuration, where an end cap 36 is fixedly attached to a lower body support member 29 (which is coupled to a device housing 38). The end cap 36 covers a proximal end opening 40 of the housing 38. As used herein, distal and proximal refer to axial locations relative to an injection site when the device is oriented for use at the injection site, thus, for example, the proximal end of the housing refers to the end of the housing closest to such injection site, and the distal end of the housing refers to the end of the housing furthest from such injection site. Also, as used herein, "injection site" can refer to the exact spot on the patient's body that is injected by the needle, as well as the body tissue surrounding the spot where the needle injects (e.g., within 1-5 cm or 1-10 cm of the spot where the needle pierces the patient's skin). The housing 38 may be shown formed from a plastic material and extending generally longitudinally along a longitudinal axis 48 between a distal end proximate the activation button 52 and a proximal end proximate the proximal end opening 40. As shown in FIG. 2, the housing 38 may include a user-graspable portion 37 configured to be grasped by a user's hand, the user-graspable portion 37 extending outwardly from the longitudinal axis 48 a radial distance 41. In some embodiments, the radial distance 41 may be 5-10 mm in length (e.g., in some embodiments, 5-8 mm may be a suitable length). Also shown in FIG. 2, the housing 38 may also include an outwardly flared end portion 39 at a proximal end of the housing adjacent the proximal opening 40. The end portion extends outwardly from the longitudinal axis 48 a radial distance 43 that is greater than the radial distance 41. In some embodiments, the radial distance 43 may be greater than 10 mm in length. For example, in some embodiments, radial distance 43 may be 10-20 mm in length (e.g., in some embodiments, 15-20 mm may be a suitable length). End portion 39 may smoothly slope radially outward from user-graspread portion 37, as shown in Figures 1-3. In other embodiments, end portion 39 may take the form of other shapes.End portion 39 may take any shape that extends away from longitudinal axis 48 a radial distance 43 that is greater than radial distance 41 of the user-graspable portion.

[0012] A needle guard 42 is mounted on the syringe assembly 22 and covers and surrounds the needle 34. The end cap 36 and needle guard 42 protect the user from accidental needle sticks and also protect the needle 34 from damage. When using the device 20 to dispense a medication, e.g., to inject the medication into a patient, the end cap 36 and needle guard 42 are first removed. Figure 2 illustrates the device 20 after the end cap 36 and needle guard 42 have been removed from the syringe assembly 22, with the syringe assembly in a stored position and the device 20 ready for a dispensing event.

[0013] The syringe assembly 22 is movable relative to the injection device 20 between a stored position and an injection position. Figure 3 illustrates the device 20 after the syringe assembly 22 has been moved relative to the device 20 from its stored position shown in Figure 2 to the injection position. In the stored position (Figures 1 and 2), the needle 34 is retracted to a position such that the needle 34 is disposed within a housing 38 of the device 20. In the injection position (Figure 3), the needle 34 projects outwardly from the housing 38 in a proximal direction parallel to the longitudinal axis 48 and beyond a proximal opening 40 so that the needle 34 may be inserted into a patient.

[0014] The drive mechanism 24 includes a plunger 44 that engages the piston 32. The drive mechanism 24 includes a spring 46 that drives the plunger 44 in a translational movement. In the exemplary embodiment, the spring 46 advances the plunger 44 along a linear path defined by a longitudinal axis 48 of the device 20. As the plunger 44 advances, a foot 50 of the plunger 44 contacts the piston 32. As the plunger 44 advances further, the syringe assembly 22 advances along the axis 48 from its retracted position to its injection position. After the syringe assembly 22 has advanced to its injection position, continued proximal advancement of the plunger 44 advances the piston 32 proximally within the barrel 30 from its initial piston position (shown in FIGS. 1 and 2 ) to its final piston position (shown in FIG. 3 ) during a dispense event, dispensing the medicament from the needle 34. Prior to any dispensing of medication, and when the syringe barrel 30 holds the entire original volume of medication, the piston 32 will be in its initial piston position. After advancing the piston 32 to its entire length of travel toward the needle assembly 33, the piston 32 will be in its final piston position adjacent the needle assembly 33, and the medication from within the barrel 30 will have been expelled. In a single use, the syringe assembly 22 will hold a single dose of medication to be delivered in a single injection event, and the piston 32 advances from its initial piston position to its final piston position during that single injection event, thereby delivering the entire single dose contents of the syringe assembly 22. Although the device is shown as a single use device, the device 20 may also be configured as a multiple use device, with appropriate modifications.

[0015] Advancement of the plunger 44 will generally not result in dispensing of medicament from the syringe assembly 22 until the syringe assembly 22 is advanced to the injection position. There are factors that may prevent medicament from being dispensed before the syringe is advanced to the injection position. The factor may be friction between the piston 32 and the barrel 30. Typically, the piston 32 will be formed of a rubber material and the barrel 30 will be glass. The frictional resistance between these two components may be sufficient to prevent advancement of the piston 32 within the barrel 30 until the syringe assembly 22 is advanced to its injection position and engagement with a suitable stop member prevents further advancement of the syringe assembly 22. Additionally, the medicament within the syringe may be somewhat viscous and therefore somewhat resistant to flowing out of the needle 34. If desired, modification of the piston 32 and syringe barrel 30 to change the frictional resistance of the dispensing motion of the engagement member 32 relative to the syringe barrel 30 may limit or prevent premature dispensing of medicament before the container 22 reaches its injection position.

[0016] To activate drive mechanism 24, a user depresses an activation button 52 on the distal end of device 20. Depressing button 52 disengages one or two elongated protrusions 54 on plunger 44 from shuttle assembly 60, thereby allowing spring 46 to advance plunger 44 axially. Spring 46 has a helical shape and surrounds protrusions 54. A proximal end of spring 46 biasingly engages a flange on plunger 44.

[0017] The shuttle assembly 60 may include an upper shuttle member 62 and a lower shuttle member 64. The shuttle members 62, 64 are secured together in the final assembly. In the final assembly, the upper shuttle member 62 captures the button 52 and the spring 46 to limit the axial movement of these components in the distal direction. The projection 54 engages a surface on the upper shuttle 62 when the device is in the state shown in FIGS. 1 and 2. Depressing the button 52 engages a tab on the button 52 with a ramp (not shown) on the projection 54, urging the projection 54 inwardly to disengage the projection 54 from the upper shuttle member 62. After the projection 54 is disengaged, the spring 46 exerts a biasing force on the flange 56 to advance the plunger 44 from the position shown in FIG. 2 to the position shown in FIG. 3. As the plunger 44 advances, it moves the syringe assembly 22 to the injection position, which in turn advances the piston 32 to dispense the medicament as discussed above.

[0018] After the dispensing event is completed, the retraction mechanism 26 optionally moves the syringe assembly 22 from the injection position shown in FIG. 3 back to the retracted position. More specifically, the retraction mechanism is adapted to move the medicament container from the injection position to the retracted position in the retraction movement. The retracted position may be similar to the retracted position in that the syringe assembly is retracted into the housing 38, such that the needle 34 no longer proximally protrudes from the proximal opening 40 but is disposed entirely within the housing 38. In some embodiments, the retracted position may be the same as the retracted position. However, in other embodiments, the syringe assembly 22 in the retracted position may be located slightly proximal or distal relative to the syringe assembly in the retracted position. In the illustrated embodiment, the retraction mechanism includes a spring 66, a syringe carrier, and a rotating member 70 acting as a follower. In still other embodiments, the device 20 may not include a retraction mechanism 26 such that the syringe assembly remains indefinitely in its injection position after the medicament has been dispensed until the syringe assembly is manually removed or repositioned by the user.

[0019] The plunger 44 may include an outrigger (not shown) that unlocks the rotating member 70 when the plunger 44 nears the end of its proximal travel. The rotating member 70 is rotatably secured to the lower shuttle member 64 by engagement between a latch and a latch recess in the lower shuttle member 64. The outrigger unlocks the member 70 by depressing the latch. A spring 66 is torsionally preloaded and has one end engaged with the member 70 and an opposing end engaged with the shuttle assembly 60. Upon depression of the latch, the spring 66 urges the member 70 to rotate.

[0020] The member 70 is rotatable within the housing 38 but is not axially movable relative to the housing 38. Other embodiments may also include an axially movable member 70. The rotation of the member 70 acts as a delay mechanism that prevents the retraction mechanism 26 from retracting the syringe assembly 22 until after the syringe assembly has finished delivering its dose of medication. The rotational speed of the member 70 may be adjusted by adjusting the viscosity of the grease disposed on or around the surface of the member 70 that is in contact with the housing 38; i.e., a more viscous grease will rotate slower and a less viscous grease will rotate faster. A radial flange of the rotating member 70 may engage a ledge in the housing member 38 to limit the proximal movement of the member 70. The spring 66 may exert an axial force, a torsional force, or both, on the member 70 proximally to bias the member 70 proximally, thereby maintaining the member 70 in an axial position where the radial flange of the member 70 engages an internal ledge of the housing member 38.

[0021] The shuttle assembly 60 may include an axially extending channel or rib that engages a corresponding feature on the housing member 38 to allow the shuttle assembly 60 to move axially within the housing 38 but prevent relative rotation of the shuttle assembly 60 with respect to the housing member 38. The shuttle assembly 60 is biased distally by a spring 66 but is prevented from moving distally by engagement of a latch (not shown) prior to activation of the drive mechanism 24. Once the rotating member 70 has completed its rotation, it disengages said latch, thereby allowing the shuttle assembly 60 to move distally under the biasing force of the spring 66.

[0022] As the shuttle assembly 60 moves distally, it carries the syringe assembly 22 distally, moving the syringe assembly 22 back to the stored position. A spring 66 biases the retraction mechanism 26 distally, thereby maintaining the syringe assembly 22 in its retracted position after an injection event. Locking mechanisms, such as detents on the shuttle assembly 60 and recesses on the housing 38 members, additionally provide a locking engagement to secure the syringe assembly 22 with the needle 34 disposed within the housing 38 in the retracted position after an injection event, such that the user can then dispose of or otherwise handle the device 20 in a safe manner.

[0023] 1-3 illustrate and describe an exemplary drive mechanism 24 and an exemplary retraction mechanism 26, other mechanisms may also be used to drive the syringe assembly 22 from the retracted position to the injection position and / or from the injection position to the retracted position. Such drive and / or retraction mechanisms may (but need not) include one or more springs or deformable parts that store energy when held in a pre-triggered state and release the stored energy when triggered to drive the syringe assembly from the retracted position to the injection position and / or from the injection position to the retracted position. Such mechanisms may (but need not) include mechanisms that generate motive force using a chemical reaction or process, for example, by generating a gas by mixing two or more reagents or by igniting a small amount of a flammable or explosive material. Such chemically driven mechanisms may include one or more containments for chemical reagents, a trigger that punctures or opens the containments to allow the reagents to mix and / or provides a spark or other ignition source to initiate a chemical reaction, and a movable piston or other component that moves in response to an increase in gas pressure generated by the resulting chemical reaction. Such mechanisms may (but are not required to) include mechanisms that use stored power (e.g., in a battery) to operate an electric motor or trigger other physical or chemical mechanisms that drive and / or retract the syringe assembly. Such mechanisms may (but are not required to) include hydraulic or pneumatic systems (e.g., tubing), gears, cables, pulleys, or other known components for transferring kinetic energy from one component to another. In some embodiments, rather than having separate mechanisms for driving the syringe assembly and then retracting the syringe assembly, a single mechanism may be configured to both drive the syringe assembly and then retract the syringe assembly.

[0024] 4 provides a system architecture diagram of electrical components within device 20 as well as a communication link with an exemplary external device 450, according to some embodiments. Device 20 may include a processing circuit 422 mounted on or within housing 38. Processing circuit 422 may be powered by power source 412 (e.g., a battery) and may include a processing core 424 and memory 426. Memory 426 may store instructions that, when executed by processing core 424, cause processing circuit 422 to perform operations described herein. Memory 426 is any suitable computer-readable medium that is accessible by processing core 424. Memory 426 may be a single storage device or multiple storage devices, may be located internal or external to processor core 424, and may include both volatile and non-volatile media. Exemplary memory 426 includes random-access memory (RAM), read-only memory (ROM), electrically erasable programmable ROM (EEPROM), flash memory, magnetic storage devices, optical disk storage, or any other suitable medium configured to store data and accessible by processor core 424 directly or indirectly through one or more intermediate devices or wired or wireless communications links. As used herein, the terms "logic," "control logic," "instructions," or "applications" may include software and / or firmware configured to execute on one or more programmable processors, field-programmable gate arrays (FPGAs), and / or digital signal processors (DSPs), or any combination of the above.Alternatively or additionally, "logic," "control logic," "instructions," or "application" may include hardwired logic (e.g., an Application Specific Integrated Circuit (ASIC)) configured to implement the functions described herein. Thus, according to an embodiment, various logic may be implemented in any suitable manner while remaining in accordance with the embodiments disclosed herein.

[0025] The processing circuitry 422 may also be communicatively coupled to a number of sensors, such as an end cap switch 414 for detecting whether the end cap 36 is attached to the device 20, an accelerometer 416 for detecting at least one of an orientation, movement, and / or acceleration of the device 20, a capacitance sensor 418 for detecting contact with skin tissue, and / or a temperature sensor 420 for detecting at least one of an ambient temperature and a temperature of the device 20. The processing circuitry 422 may also be connected to a device for providing user feedback 432 integrated with the device 20. The means for user feedback may include one or more indicator lights (e.g., implemented using light-emitting diodes (LEDs)), a display, a tactile indicator such as a vibration motor, and / or an audio indicator such as a speaker. The processing circuitry 422 may be communicatively coupled to each of the aforementioned components via one or more physical, electrical channels, such as, but not limited to, General-Purpose Input / Output (GPIO) pins, an Inter-Integrated Circuit (I2C) bus, a Serial Peripheral Interface (SPI) connection, a Universal Asynchronous Receiver / Transmitter (UART) connection, a Controller Area Network (CAN) bus, etc. In some cases, signals received by the processing circuitry 422 from some or all of the sensors may also be converted from analog to digital signals using an analog-to-digital converter (ADC). In some embodiments, the processing circuitry 422 may take the form of a System on Chip (SOC) integrated circuit.In some embodiments, the processing circuitry 422 may also be implemented using other types of components, such as a microcontroller (MCU) or an Application Specific Integrated Circuit (ASIC).

[0026] The processing circuit 422 may also be configured to enable the injection device 20 to communicate wirelessly with an external device, such as, for example, a mobile phone, a wearable device, a laptop, and / or a server database. To facilitate wireless communication, the processing circuit 422 may include a Bluetooth Low Energy (BLE) circuit 428 communicatively coupled to a BLE antenna 430. The BLE circuit 428 and the BLE antenna 430 enable the processing circuit 422 to establish a wireless BLE communication link 440 with an external device 450. The wireless BLE communication link 440 may transfer data in only one direction (e.g., from the delivery device 20 to the external device 450) or in both directions. The wireless link 440 may be a BLE wireless communication session established after a Bluetooth handshake or pairing process, but it may also include the transmission of data prior to or without any handshake or pairing process. Although the embodiment shown in FIG. 4 shows a BLE circuit and antenna, any suitable wireless communication standard may be used.

[0027] FIG. 4 also illustrates an exemplary external computing device 450 that is physically separate from the injection device 20. In this embodiment, the exemplary external device 450 may take the form of a mobile smart phone. Alternatively, any suitable computing device may be used, including, but not limited to, a smart watch, laptop, desktop, tablet, or server computer. The external device 450 may comprise a processor 452 (e.g., a microprocessor or CPU) and a storage 458. The storage 458 may comprise a non-transitory computer-readable medium storing computer-executable instructions that, when executed by the processor 452, cause the device 450 to perform the operations described herein. These computer-executable instructions may include a mobile application, such as a medical mobile application. The device 450 may further comprise a display 460 and a user input device 462. The user input device 462 may comprise physical buttons, switches, or other types of input devices integrated with or communicatively coupled to the device 450, such as a keyboard, keypad, microphone, mouse pointer, or other suitable user input device. 4, all or a portion of the user input device 462 may be integrated with the display 460, for example, in a touch-sensitive screen operable to display data and receive user input. The device 450 may be configured to establish a wireless communications link 440 with the injection device 20. For example, the external device 450 may include a BLE circuit 456 communicatively coupled to a BLE antenna 457 that communicates with a processing circuit 422 within the device 20 via the communications link 440.

[0028] As described herein, the drug delivery device 20 may be configured to generate data regarding the status of the device 20 and / or data regarding the occurrence of certain events or actions. For example, the processing circuitry of the drug delivery device may analyze signals from an accelerometer to determine when an injection event begins and / or is completed. As another example, the processing circuitry may analyze signals from a skin contact sensor to verify proper contact with the user's skin before and / or during the initiation of an injection event. In some embodiments, the generated data is provided to the external device 450 so that the external device 450 can be used to monitor injection event activity and / or the status of the drug delivery device. In some embodiments, the data generated by the device 20 and provided to the external device 450 may include information regarding the time of the injection event, the time elapsed since the injection event, the date of the injection event, the temperature of the drug stored in the drug delivery device, the status of the skin contact sensor, or any other suitable data, and aspects of the techniques described herein are not limited in this respect. A mobile application on the computing device may be used to log data received from the drug delivery device (e.g., injection event information), such as the time and / or date of the injection event. In some embodiments, this can help users adhere to their injection regimen, as injection event information is automatically and accurately logged.

[0029] The exemplary electrical components of FIG. 4 may be modified in several ways in different embodiments. For example, in some embodiments, some of the sensors 414, 416, 418, and 420 may be omitted. In addition to the sensors 414, 416, 418, and 420, other sensors may be connected to the processing circuitry 422, such as one or more microswitch sensors for detecting the movement or position of various components in the device 20, an ambient light sensor for detecting the presence, absence, and / or intensity of ambient light, and / or a magnetometer for detecting the movement or position of various components (e.g., the plunger 44) in the device 20. The device 20 may also omit the user feedback 432 in some embodiments. In some embodiments, in addition to or as an alternative to the BLE circuitry 428 and the BLE antenna 430, the processing circuitry 422 may include or be connected to other types of wireless communication circuitry, such as an RFID circuitry and / or an RFID antenna, or an NFC circuitry and / or an NFC antenna.

[0030] As previously discussed, the processing circuit 422 may be mounted anywhere on or within the housing 38 of the device 20. For example, the processing circuit 422 may be mounted near the distal end of the device 20, within, surrounding, or immediately proximal to the button 52. The processing circuit may be located anywhere along the length of the user-gripable portion 37 of the housing 38. In some embodiments, the processing circuit 422 may be embedded within the housing 38. In other embodiments, the processing circuit 422 may be removably or permanently mounted on the exterior of the housing 38.

[0031] In some embodiments, the processing circuit 422 may be mounted on the lower body support member 29 adjacent the proximal end of the device 20 at the outwardly flared end portion 39 adjacent the proximal opening 40. FIGS. 5, 6A, and 6B show one such embodiment, where the processing circuit 422 is mounted on a printed circuit board (PCB) 500 disposed on the lower body support member 29. As shown in FIG. 5, the lower body support member 29 comprises a hollow, substantially cylindrical body 502 that surrounds the needle 34 (illustrated in FIGS. 1-3). The cylindrical body 502 is mounted on a proximal plate 504, which in this embodiment has a trilobal shape. Both bodies 502 and 504 may be formed from any suitable rigid material, such as a rigid polymer or metal. The bodies 502 and 504 may be manufactured separately and then joined together using any suitable joining method, including screws, adhesives, pressure fitting, ultrasonic welding, or other suitable techniques. Alternatively, bodies 502 and 504 may be manufactured as a single monolithic component. PCB 500 may be attached to a distal surface of proximal plate 504. PCB 500 may be shaped substantially similarly to proximal plate 504 (e.g., in this embodiment, taking the shape of a trilobe plate) so as to cover a majority of the distal surface of plate 504. PCB 500 may also define a lumen 506 configured to receive cylindrical body 502 therethrough.

[0032] FIG. 6A illustrates a distal view of the PCB 500, and FIG. 6B illustrates a proximal view of the PCB 500. As shown, the PCB 500 may include a battery clip and / or contacts 412′ configured to receive and draw power from a battery 412. The PCB 500 may further include a BLE antenna 430 configured to wirelessly communicate with a remote device (e.g., device 450), as described herein. The PCB 500 may further include a processing circuit 422, as well as a temperature sensor 420 and a user feedback device 432 (not shown in FIGS. 6A, 6B), as described herein. The PCB 500 may also include an end cap switch 414 configured to detect whether an end cap 36 is attached to the proximal end of the device 20, as described herein. In some embodiments, the end cap switch 414 may take the form of a physical switch that is biased to a first state by the end cap 36 or one or more intermediate deformable members in contact with the end cap 36 when the end cap 36 is attached. When the end cap 36 is removed, the end cap switch 414 may be biased to a second state. The end cap switch 414 may output different electrical signals depending on whether the end cap switch 414 is in the first state or the second state. These signals may be provided to the processing circuitry 422 to enable the processing circuitry to determine whether the end cap 36 is attached or not.

[0033] The proximal side of the PCB 500 further comprises two capacitive touch pads 418a and 418b (collectively referred to as 418) as described herein. The capacitive touch pad 418 may be configured to detect whether the touch pad 418 is positioned in contact with or in close proximity to skin tissue based on the measured capacitance. In particular, such a capacitive sensor may be configured to detect the proximity of human tissue (e.g., skin tissue) by detecting the effect of such tissue on the electric field created by the sensor (e.g., by detecting the effect of such tissue on the capacitance of a circuit being monitored or measured by the sensor). Because a capacitive sensor does not require a metal electrical terminal in direct contact with tissue, it may be partially or completely encapsulated behind a protective non-conductive cover (e.g., made from plastic).

[0034] The distal side of PCB 500 further comprises accelerometer 416. Accelerometer 416 may also detect an impact or acceleration caused by the initiation of a dispense event in which syringe assembly 22 is driven from the retracted position to the injection position by drive mechanism 24. Accelerometer 416 may also detect an impact or acceleration caused by a retract movement upon completion of a dispense event in which syringe assembly 22 is driven from the injection position to the retracted position by retraction mechanism 26. Accelerometer 416 may send an output signal to processing circuit 422 via one or more electrical connections to enable the processing circuit to analyze the output signal.

[0035] In some embodiments, processing circuitry 422 may analyze signals output from accelerometer 416 to determine a particular condition or state of device 20 or to detect the occurrence of a particular event or action. For example, processing circuitry 422 may be configured to determine when a dispense event starts or completes based on signals from accelerometer 416, alone or in conjunction with signals from other sensors (e.g., capacitive skin contact sensor 418). Methods for determining when a dispense event starts or completes are described in further detail in U.S. Patent Application Publication No. 2021 / 0093784(A1) to Adams et al., published April 1, 2021, the entire disclosure of each of which is incorporated herein by reference.

[0036] When a dispense event is initiated, the drive mechanism 24 is actuated to drive the syringe assembly 22 from the retracted position to the injection position. This drive motion imparts one or more accelerations that can be detected in the signal output from the accelerometer 416. For example, the pushing force imparted by the drive mechanism 24 as it drives the syringe assembly 22 proximally from the retracted position can cause the accelerometer 416 to detect an acceleration in the distal direction along the longitudinal axis 48. When the syringe assembly 22 hits its stop position at its injection position at the end of this drive motion, the sudden stop of the syringe assembly 22 can cause the accelerometer 416 to detect an acceleration in the proximal direction along the longitudinal axis 48. Either this proximal or distal acceleration (or both) can cause the accelerometer 416 to output a first acceleration spike that can be detected by the processing circuit 422. This first acceleration spike can indicate the start of a dispense event.

[0037] Similarly, when the dispense event is completed, the retraction mechanism 26 is actuated to drive the syringe assembly 22 from the injection position to the retracted position. This drive motion imparts one or more accelerations that may also be detected in a signal output from the accelerometer 416. For example, a pushing force imparted by the retraction mechanism 26 as it drives the syringe assembly 22 distally from the injection position may cause the accelerometer 416 to detect an acceleration in the proximal direction along the longitudinal axis 48. Once the syringe assembly 22 reaches the retracted position, a sudden stop of the syringe assembly 22 may cause the accelerometer 416 to detect an acceleration in the distal direction along the longitudinal axis 48. Either this proximal or distal acceleration (or both) may cause the accelerometer 416 to output a second acceleration spike that may be detected by the processing circuit 416. This second acceleration spike may indicate the completion of the dispense event. As used herein, an "acceleration spike" is defined as any artifact of an acceleration or vibration signal output by an accelerometer or vibration sensor (e.g., a piezoelectric sensor) that indicates the start and / or completion of a dispensing event. When (or thereafter) the processing circuit 422 detects the start and / or completion of a dispensing event, the processing circuit 422 may transmit injection event information to the external device 450. As previously described herein, such injection event information may include the time of the injection event, the time elapsed since the injection event, the date of the injection event, the temperature of the medication stored within the medication delivery device, the state of the skin contact sensor, or any other suitable data.

[0038] The device 20 can be used to deliver injections of the stored medication to any suitable injection site on the patient's body, such as the patient's left or right thigh, left or right thigh, left or right buttock, or under the patient's left or right upper arm. However, depending on the patient's body physiology, the inventors recognize that injections at some injection sites may result in less injection site pain at the time of injection than other injection sites. Also, depending on the patient's body physiology, some injection sites may result in less injection site pain minutes and hours after injection than other injection sites, for example, due to a lower inflammatory response or other injection response at the injection site. Therefore, it is desirable to provide guidance to the user and / or patient regarding which injection sites may result in less pain.

[0039] The inventors have also realized that the capacitive touch pad 418 on the device 20 may be used to collect data regarding the physiology of different injection sites on the patient's body. Such data may be used by the device 20 and / or the external device 450 to provide the user with insight regarding the pain levels the patient is expected to experience from potential injections at different injection sites. In general, injections at injection sites with higher fat content are expected to be less painful for the patient, both at the time of injection and minutes and hours after injection, compared to injection sites with lower fat content. Furthermore, injection sites with more fat content are expected to have a lower capacitance as measured by the capacitive touch pad 418, compared to injection sites with less fat content. This is because injection sites with higher fat content are expected to have a lower water content (and therefore lower capacitance) compared to injection sites with lower fat content.

[0040] FIG. 7 presents an exemplary logic 700 for assessing an injection site on a patient's body using capacitance data collected by a capacitance sensor, according to some embodiments. In step 702, a user is instructed to place one or more capacitance sensors in contact with a potential injection site on the patient's body (e.g., the right thigh). For example, these instructions may be provided to the user using the display 460 of the external device 450. Exemplary processes / methods for instructing the user to do so are described in more detail below, for example, in FIGS. 8 and 10A-10K. In some embodiments, these capacitance touch pads may be capacitance touch pads 418 on an injection device, such as device 20. In other embodiments, other types of capacitance sensors may be used, whether or not coupled to a drug delivery device.

[0041] In step 704, a processing circuit in communication with the one or more capacitance sensors may receive a signal indicative of the capacitance of the body tissue at the potential injection site as measured by the one or more capacitance sensors. This processing circuit may be the processor 452 in the external device 450, but may also be the processing circuit 422 in the device 20.

[0042] In step 706, the processing circuit determines an expected pain level that the patient will experience from the anticipated injection at the potential injection site based on the received signal. Generally, a lower capacitance may be associated with a lower expected injection site pain level, since a lower capacitance indicates less water content, which indicates more fat content at the injection site. Conversely, a higher capacitance may be associated with a higher expected injection site pain level. The pain level may be determined in different ways. In some embodiments, the pain level may be a classification of the injection site into one of two pain levels (e.g., "low" pain or "high" pain), three pain levels (e.g., "low" pain, "medium" pain, or "high" pain), or more pain levels (any number of pain levels may be used). In such embodiments, the pain level may be determined by comparing the measured capacitance to one or more pre-programmed thresholds that define the capacitance boundaries between each injection site pain level. In some embodiments, the expected pain level may be a numerical score or a value along a range of values. In such embodiments, a predicted pain level may be generated by comparing the measured capacitance to a range of predicted capacitance values ​​for different injection sites on an average human body, i.e., the determined predicted pain level may include an indication of where the measured capacitance lies within the predicted range.

[0043] In some embodiments, the determined predicted pain level may be stored in memory (e.g., storage 458 or memory 426) for later analysis or presentation. The determined predicted pain level may also be transmitted to another device via a wired or wireless communication link for storage or further analysis. For example, the generated indicator may be transmitted, either directly or via one or more optional intermediate components, to a desktop or laptop computer for storage or analysis, and / or transmitted over a network to a remote server for storage or analysis.

[0044] In some embodiments, the determined expected pain level may also be optionally presented to the user for visual confirmation. For example, in step 708, the processing circuitry generates and presents an indication of the determined expected pain level to the user. The generated indication may be presented to the user using any of the previously described user feedback devices 432 integrated with the device 20. As an exemplary embodiment, the device 20 may comprise an array of LEDs, each LED in the array corresponding to a different injection site. The generated indication may be presented to the user by lighting each LED in the array with a different color, intensity, duration, and / or pattern indicative of the expected level of pain associated with each injection site. In another embodiment, the device 20 may comprise a single LED that lights up with different colors, intensities, durations, and / or patterns depending on the expected pain level associated with a single injection site, for example, the injection site that was most recently measured or is currently being measured by the capacitive touch pad 418 on the device 20. Alternatively or additionally, the device 20 may be provided with a small speaker for providing an audible message to the user, including the generated indication described above. In some embodiments, alternatively or additionally, this generated indicator may be presented to the user via a display 460 on the external device 450. Some examples of logic for presenting such generated indicators on the external device 450 are described below in connection with Figures 8 and 9.

[0045] 8 illustrates an example logic 800 for collecting capacitance data and generating insights regarding potential injection site pain, according to some embodiments. For ease of explanation, the logic 800 will be described herein as being implemented by the external device 450 based on data received from the capacitance sensor 418 from the device 20. However, it should be understood that in embodiments where the device 20 is equipped with a user interface and / or user input device (e.g., a display and buttons, or a touch-sensitive display) suitable for communicating the described data and screenshots to a user, the logic 800 may also be implemented solely on the device 20. In some embodiments, certain portions of the logic 800 may be implemented by the external device 450, while other portions may be implemented by the processing circuitry 422 on the device 20, such that the device 450 and the device 20 cooperate to implement the logic 800.

[0046] When a user activates logic 800 (e.g., by launching a mobile application on external device 450 or by initiating a function within such mobile application), external device 450 begins by presenting an initial injection site assessment (step 804). This assessment may include initial guidance comparing the expected injection site pain level the patient will experience upon injection for different potential injection sites. For example, this assessment may include a score, color, or other indicator of the expected injection site pain of different injection sites on the patient's body. This assessment may also include a ranking of the injection sites on the patient's body from most painful to least painful or least painful to most painful.

[0047] If the user has not previously invoked logic 800, such initial guidance may be based on pre-programmed parameters of an "average" patient informed by the results of experimentation or experience with a patient population, but not based on any physiological data collected about the particular patient being injected. If the user has previously invoked logic 800, such initial guidance may alternatively or additionally be based on previously measured or collected data about the particular patient being injected. In some embodiments, if pre-programmed parameters of an "average" patient are not provided and previously recorded data of the patient to be injected is not available, the injection site assessment presented in step 804 may be a null or unpopulated assessment.

[0048] FIG. 10A provides an exemplary screenshot for the initial injection site assessment provided in step 804. FIG. 10A shows a front view of the body on the left side of the screen and a back view of the body on the right side. Potential injection sites are highlighted on the diagram using ellipses. In this embodiment, the following injection sites are highlighted: left and right abdomen, left and right thighs, left and right hips, and under the left and right upper arms. In this embodiment, since no data is available for either the "average" patient or the specific patient being injected, all ellipses are colored gray to indicate that no data is available.

[0049] The logic 800 continues at step 806 where the external device 450 waits for user input as to whether to proceed with the injection or to collect additional injection site data. If the external device 450 receives user input indicating "proceed to inject," the logic branches to logic 900, discussed with respect to Figure 9. If the external device 450 receives user input indicating that the user wishes to collect additional injection site data, the logic 800 branches to step 808.

[0050] In step 808, the external device 450 receives input from the user indicating potential injection sites on the patient's body for which the user would like to collect data. FIG. 10B provides an exemplary screenshot of this step. In this example, from the screenshot of FIG. 10A, FIG. 10B may be reached when the user presses the button "Help me find the best site." In FIG. 10B, if the user wishes to branch to logic 900, the user may press "Proceed to injection." However, if the user wishes to branch to step 808, the user may indicate a potential injection site on the patient's body by touching one of the indicated injection sites on the illustrated body diagram. In this embodiment, the user has selected an injection site corresponding to the patient's right thigh. When the user touches that injection site, the injection site on the right thigh of the body diagram changes appearance to indicate that the injection site has been selected (as indicated by the symbol "X").

[0051] In step 810, the external device 450 and the device 20 cooperate to collect capacitance data and generate a pain index for the selected potential injection site. For example, the user may place the capacitive touch pad 418 on the device 20 against the selected injection site (in this example, the right thigh). The processing circuitry 422 on the device 20 may read and record the capacitance value measured by the touch pad 418 during this touch, as previously described in connection with FIG. 7, and then transmit the recorded value to the external device 450 to generate a pain index. If desired, the user may be prompted to lift and place the device 20 over the selected potential injection site several times so that the device 20 may read, record, and transmit multiple recorded capacitance values ​​to the external device 450, with multiple readings making the resulting pain index more accurate. If multiple readings are taken, these readings may be averaged to generate a total capacitance reading, which in turn may be used to generate an overall pain index for that injection site. Once the external device 450 has received sufficient capacitance data to generate a pain indicator for the selected injection site, the selected injection site may again change appearance (as indicated by the dark color of the right thigh in FIG. 10C) to indicate that sufficient data has been collected.

[0052] After collecting sufficient capacitance data for the selected injection site, logic 800 branches back to step 806 and the user is again presented with the option to proceed with the injection or to collect additional injection site data. In Figure 10C, if the user selects the button "Proceed to Inject?", logic 800 branches to logic 900 of Figure 9. However, if the user selects "Continue Touch Data?", logic 800 branches back to step 808.

[0053] In the example illustrated in FIG. 10C, the user selects “Continue touch data?”, which takes the user to the example screenshot illustrated in FIG. 10D (and returns the user to step 808 of logic 800). Here, the user is again presented with a front and back view of the human body with the injection site highlighted. However, this time, data has already been collected for the right thigh, so the right thigh injection site is colored differently than the other injection sites to indicate that this is the case. The user selects another injection site (in this example, the left thigh) for data collection. After selecting the left thigh, the user again places the capacitance pad 418 on the device 20 against the selected injection site (the left thigh as indicated by the “X” symbol) to collect capacitance data. Once sufficient data has been collected for the left thigh injection site, the left thigh injection site changes appearance as shown in FIG. 10E. After collecting the left thigh data, the user is again presented with the option of "Proceed to injection?" (which takes the user to logic 900 of FIG. 9) or "Continue touch data?" (which takes the user back to step 808).

[0054] This causes the user to cycle through steps 806, 808, and 810 indefinitely until the user has collected data for all available injection sites or the user selects "Proceed to Inject." FIG. 10F illustrates an example screenshot where the user has collected data for all eight illustrated injection sites. In this screenshot, there is no longer a "Continue Touch Data?" option since data has been collected for all injection sites. Instead, the user is presented with the option to press a button labeled "Proceed to Inject?".

[0055] When the user presses the "Proceed to Inject" button, logic 800 branches to logic 900 of FIG. 9. In step 901, external device 450 presents an assessment of different injection sites on the user's body based on previously collected capacitance data. This step may be similar to the assessment presented in step 804. As previously described, this assessment may include a score, color, or other indicator of expected injection site pain of different injection sites on the patient's body. This assessment may also include a ranking of the injection sites on the patient's body from most to least painful or least to most painful.

[0056] FIG. 10G provides an example screenshot of an injection site assessment provided in step 901. FIG. 10G is similar in appearance to FIG. 10A, but as capacitance data has been collected for each injection site on the body, each injection site is filled with a color indicating the expected injection site pain level for that site. In this example, injection sites colored lighter are expected to indicate relatively low injection site pain, sites colored medium gray are expected to indicate a medium injection site pain level, and sites colored dark gray or black are expected to indicate a relatively high injection site pain level. In general, any color scheme may be used to indicate the expected injection site pain. The expected injection site pain level may be generated from the collected capacitance data using any of the techniques previously described in connection with FIG. 7.

[0057] If the user presses the button labeled "Proceed to Inject?", the logic 900 proceeds to step 902, where the external device 450 receives a user input indicating a selected injection site. FIG. 10H provides an example screenshot showing how the external device 450 may receive this input. Here, the user is instructed to press one of the displayed injection sites on a front / back body diagram. In this example, the user is touching the right abdominal injection site. The external device 450 may provide feedback confirming the user's selected site, for example, by adding a symbol (a plus sign as shown in FIG. 10H) to the selected site, changing the color, size, weight, outline, or other visual aspect of the selected site, and / or by providing a text or audible confirmation. In some embodiments, the external device 450 may also confirm the user's selected site not by changing the appearance of the selected site, but by changing the appearance of all non-selected sites. An example of this embodiment is shown in FIG. 10I, where the selected site (right abdominal) remains unchanged, while all non-selected sites are grayed out. FIG. 10I also includes a banner or notification at the top of the screen confirming to the user that an injection site has been selected.

[0058] In step 904, the external device 450 receives injection event data indicating that an injection or dispense event has occurred. As described herein, this injection event data may be communicated from the medication delivery device 20 to the external device 450 via the wireless BLE communication link 440. As previously described, this data may include information regarding the time of the injection event, the time elapsed since the injection event, the date of the injection event, the temperature of the medication stored within the medication delivery device, the status of the skin contact sensor, or any other suitable data, and aspects of the techniques described herein are not limited in this respect. The external device 450 assumes that the injection event data received in step 904 relates to an injection delivered to the injection site selected in step 902.

[0059] In step 906, the external device 450 receives an input indicating the injection pain level actually experienced by the patient at the time of the injection. The device 450 may solicit this input from the user by prompting the user with one or a series of questions. Alternatively, the user may provide such input without any active prompting from the device 450. The input received by the device 450 may include a numerical score, the operation of a slider or knob, or the selection of one of a number of buttons or options indicating the pain level actually experienced by the patient.

[0060] In step 908, the external device 450 logs in memory the injection event data received in step 904. The log may also include supplemental data calculated by the external device 450 based on the injection event data received in step 904, but not included in the injection event data. For example, the injection event data may include data indicating the amount of time that has elapsed since the injection event, e.g., in minutes or seconds. The external device 450 may consult a digital clock on board the external device and determine, based on the injection event data, that the injection occurred at a particular time and / or date (e.g., 11:01 a.m. EST on June 15, 2021) and include the determined time in the log entry. The log entry may also indicate that the injection event described by the injection event data was injected at the injection site selected in step 902. Additionally or alternatively, the log entry may also indicate the injection pain level actually experienced by the patient at the time of the injection, received in step 906. Generally, in this step, the device 450 associates the injection event data received in step 904 with the injection site selected in step 902 and / or the injection site pain data received in step 906. This association may take the form of a volatile or non-volatile record stored in memory of the device 450. In some embodiments, the external device 450 may display a confirmation screen (e.g., as shown in FIG. 10J) informing the user that the injection event, selected injection site, and / or indicated injection site pain level have been successfully logged.

[0061] In step 910, the external device 450 waits for a preprogrammed period, such as 1-3 hours. As used herein, "preprogrammed" does not mean that the value cannot be changed after initial programming. For example, in some embodiments, the preprogrammed period may be modified by a user, such as a caregiver or a patient. Also, in some embodiments, the external device 450 may automatically apply different preprogrammed periods depending on different factors, such as the type of injection device, the medication being injected, the selected injection site, the time of day, patient data (e.g., the patient's medical or historical data), patient preferences, etc. In step 912, the external device 450 receives additional input indicating the injection pain level experienced by the patient at the injection site where the injection event was received. As previously described, the device 450 may solicit this input from the user by prompting the user with one or a series of questions. The input received by the device 450 may include a numerical score, the operation of a slider or knob, or the selection of one of a number of buttons or options indicating the pain level actually experienced by the patient. This off-set user input may indicate the pain level caused by any post-injection reaction of the patient's tissue at the injection site.

[0062] In step 914, the external device updates the injection event log entry saved in step 908 with the additional user input provided in step 912. The logic 900 ends after step 914.

[0063] Upon completion of logic 900, external device 450 may maintain a log of the time / date of the completed injection event, the injection site at which the injection event was received, the pain level reported by the patient at the time of the injection, and / or the pain level reported by the patient 1-3 hours after completion of the injection, as previously described. When the patient next activates logic 900 (e.g., by launching a mobile application or by initiating a function within such mobile application), this data may be used to update or supplement the initial guidance previously described in connection with step 904. As the patient continues to administer and log injections using logic 800 and 900, the data in such logs may provide increasingly detailed and specific data regarding the injection site pain experienced by the patient and may be used to generate this initial guidance. In this way, the initial guidance of the external device 450 may be based on population-level averages (or the device 450 may not provide any guidance at all by default), but as the patient continues to use the logic 800 and 900 to perform injections, the device 450 "learns" from the user's past experiences with injections and provides increasingly tailored guidance regarding the patient's specific expected injection pain.

[0064] For example, the initial guidance provided in step 804 may be similar to the guidance provided to the user in step 901 after capacitance data has been collected during implementation of logic 700 and 900. In some embodiments, the guidance provided in step 901 may be further modified and / or augmented by the pain level previously reported by the patient in steps 906 and 914. If external device 450 predicted a first pain level based on capacitance data at, for example, the right abdominal injection site, but reports that a different pain level was actually experienced at the time of injection (or 1-3 hours after injection), the predicted pain level at the right abdominal site may change to reflect the pain actually experienced.

[0065] The data captured by recording patient-reported injection site pain at either the time of injection and / or 1-3 hours after injection may also be used in other ways. For example, patient-reported injection site pain may be used to characterize a patient's pain tolerance. If a patient reports relatively low injection site pain (either at the time of injection or at some time after injection, and potentially across multiple injections), the patient may be classified as having a relatively high pain tolerance. Conversely, if a patient reports relatively high injection site pain (either at the time of injection or at some time after injection, and potentially across multiple injections), the patient may be classified as having a relatively low pain tolerance. This may be an important insight for a healthcare provider advising or providing care to a patient. In some cases, to better control for variability in how different patients report their injection site pain, the variability in patient-reported pain scores may be compared to the variability in capacitance measured at different injection sites to classify patients as having a relatively high or relatively low pain tolerance. In this embodiment, patients with high pain tolerance may be expected to report pain scores that do not vary significantly from one another (e.g., uniformly low), even when different injection sites on the patient's body show large measured capacitance differences. Conversely, patients with low pain tolerance may be expected to report pain scores with significantly higher variance (e.g., ranging from low to high), especially when different injection sites on the patient's body show large measured capacitance differences. In yet other cases, patients with very low pain tolerance may be expected to report uniformly high pain scores with low variance. Thus, the variability of pain scores reported by patients may also be used, either alone or in combination with absolute score values, to classify patients as having relatively high or relatively low pain tolerance.

[0066] Alternatively, or additionally, data captured by recording patient-reported injection site pain at the time of injection and / or any one to three hours after injection may be used to compare pain caused by different drug products, pain caused by different formulations of a drug product, or even pain caused by different batches of the same drug product. For example, a first set of subjectively experienced and self-reported pain scores may be collected from a population of patients who self-administered a first drug type (or a first drug formulation, or a first drug batch), and a second set of pain scores may be collected from a similar (or the same) population of patients who self-administered a second drug (or a second drug formulation, or a second drug batch). The first set of subjectively experienced and self-reported pain scores and the second set of pain scores may be compared to derive insights regarding which drug (or drug formulation, or drug batch) resulted in greater or less injection site pain. When different drug batches are compared to each other, the batches may differ from each other in any of a number of ways. For example, the batches may be manufactured in different ways, or may be stored, manufactured, or handled in different ways, and may be exposed to different conditions (e.g., temperature changes) and other differences. The method presented in Figure 9 for collecting subjectively experienced and reported pain scores from injection site pain may be used to derive insights into how injection site pain differs across any of the aforementioned dimensions.

[0067] In some embodiments, in addition to or as an alternative to providing guidance on expected injection site pain, the external device 450 may provide guidance on expected levels of pharmaceutical effectiveness of a drug injected into different injection sites. The inventors have appreciated that the same type and amount of injected drug may result in different levels of pharmacokinetic / pharmacodynamic (PK / PD) effectiveness (also referred to herein as pharmaceutical effectiveness) based on the injection site. For example, injecting a drug into the abdomen may result in greater or lesser PK / PD effectiveness compared to injecting the same drug into the thigh or upper arm. The circumstances under which PK / PD effectiveness differs by injection site may also vary depending on the type of drug injected. For example, one type of drug may exhibit greater PK / PD effectiveness when injected into the abdomen, while another type of drug may exhibit greater PK / PD effectiveness when injected into the thigh. The circumstances under which PK / PD effectiveness differs by injection site for a particular type of drug may be observed experimentally in clinical trials. Therefore, it would also be desirable for the external device 450 to provide and / or integrate guidance as to which injection site may provide greater PK / PD efficacy.

[0068] FIG. 10K presents an exemplary screenshot presenting the overall suitability of different injection sites based on both (i) the expected PK / PD efficacy level of the drug injected at each site, and (ii) the expected injection pain level associated with each site. Lighter colored sites indicate more preferred injection sites, and darker colored sites indicate less preferred injection sites. In this embodiment, the PK / PD efficacy of each site may be based on experimental data for a particular type of drug collected in clinical trials and pre-programmed into the external device 450. For example, if clinical trials have established that for a particular type of drug, drugs injected into the abdomen exhibit high PK / PD effects, drugs injected into the upper arm or buttocks exhibit moderate PK / PD effects, and drugs injected into the thigh exhibit low PK / PD effects, this data may be pre-programmed into the external device 450. The shading of the different injection sites on FIG. 10K may be based on a weighted combination of PK / PD efficacy and expected injection site pain. The weighting between PK / PD efficacy and expected injection site pain may be a pre-programmed and / or configurable parameter.

[0069] In this embodiment, if the user presses the button at the bottom of FIG. 10K, "Exclude PK / PD," the shading in FIG. 10K may change by excluding the PK / PD efficacy data, and instead, present only the predicted injection pain data. If the user presses the "Exclude Pain" button, the shading in FIG. 10K may change by excluding the injection pain data, and instead, present only the PK / PD efficacy data. In yet other embodiments, the screenshot of FIG. 10K may be further modified to provide the user with the option to adjust the weighting used to combine the PK / PD efficacy and predicted injection site pain.

[0070] Although the logic 700, 800, and 900 are described above with respect to an embodiment in which the drug delivery device 20 communicates wirelessly with the external device 450, the logic described above may be modified to be implemented in the drug delivery device 20 alone. As previously described, the drug delivery device 20 may be equipped with a device 432 for providing user feedback, such as one or more indicator lights, a display, a tactile indicator, and / or a speaker for providing audible feedback. In some alternative embodiments, the drug delivery device 20 may incorporate a display screen that displays screenshots similar to those previously discussed with respect to Figures 10A-10K. In other embodiments, the aforementioned pain and / or suitability / desirability indicators may be delivered using one or more light emitting diodes (LEDs). For example, the device 20 may be provided with multiple LEDs, each LED corresponding to a different injection site on the user's body. As capacitance data for each injection site is collected and / or as patient-reported experiences associated with each injection site are collected, an LED corresponding to each injection site on the device 20 may change color to indicate the level of expected pain level and / or the level of suitability / desirability of each injection site based on expected PK / PD efficacy and / or pain, as described herein. In other embodiments, the device 20 may provide a single LED that changes color in response to capacitance data collected by the capacitance sensor. In such embodiments, the device 20 may provide only one pain level at a time. In still other embodiments, the device 20 may provide a small speaker to provide an audible message to the user and provide the aforementioned indications of pain and / or suitability / desirability. All of the embodiments described herein for providing the aforementioned indications are not exclusive, and any or all of these embodiments may be used together. For example, the device 20 may be configured to communicate with the external device 450 and provide an indication via one or more LEDs.

[0071] The terms "first," "second," "third," and the like, whether used herein or in the claims, are provided to distinguish between similar elements and do not necessarily describe a sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances (unless expressly disclosed otherwise) and that the disclosed embodiments described herein are capable of operating in other orders and / or configurations other than those described or illustrated herein.

[0072] While the invention has been described as having an exemplary design, the invention can be further modified within the spirit and scope of the disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the disclosure as come within known or customary practice in the art to which this invention pertains.

[0073] Various aspects are described in this disclosure, including but not limited to the following aspects. 1. A method for assessing an injection site on a patient's body, the method comprising: receiving, in a processing circuit in communication with one or more capacitance sensors positioned at a potential injection site on the patient's body, a signal indicative of the capacitance of body tissue at the potential injection site as measured by the one or more capacitance sensors; and determining, by the processing circuit based on the received signal, an expected pain level that the patient will experience from an anticipated injection at the potential injection site. 2. The method of aspect 1, wherein the one or more capacitance sensors are disposed on a drug delivery device containing the drug, and the processing circuit is disposed in a mobile device that wirelessly communicates with the drug delivery device. 3. The method of aspect 1 or 2, further comprising presenting, by the processing circuitry, to the user an indication of the determined predicted pain level via at least one of a visual indication from a light emitting diode (LED), a visual indication on a display screen, an audible indication, and a tactile indication. 4. The method of embodiment 3, wherein the indicator includes a color-coded diagram of at least a portion of the human body on the display screen. 5. The method of any one of aspects 1-4, further comprising generating, by the processing circuitry, an indication of an overall suitability of the potential injection site based on both (i) the determined expected pain level and (ii) a pre-programmed expected level of pharmaceutical effect that the patient would experience from an anticipated injection at the potential injection site. 6. The method of any one of aspects 1-5, further comprising receiving, in the processing circuit, a user input from the patient indicating at least one of a pain level actually experienced by the patient at the time of the actual injection at the potential injection site and a pain level actually experienced by the patient at a pre-programmed time after the time of the actual injection. 7. The method of embodiment 6, wherein the preprogrammed time is greater than or equal to 1 hour after the actual injection and less than or equal to 3 hours after the actual injection. 8. The method of aspect 6 or 7, further comprising the step of revising the determined expected pain level based on previously received user input. 9. The method of aspect 3, wherein the potential injection site is a first potential injection site, the method further comprising receiving, in the processing circuit, a signal indicative of a capacitance of bodily tissue at a second potential injection site of the patient's body as measured by one or more capacitance sensors, and wherein the presented indication comprises an indication of whether an expected pain level that the patient would experience from an expected injection at the first potential injection site is expected to be greater or less than an expected pain level that the patient would experience from an expected injection at the second potential injection site. 10. The method of aspect 9, further comprising injecting the medication into one of the first potential injection site and the second potential injection site based on the generated indication. 11. A processing device for evaluating an injection site on a patient's body, the device comprising: a memory having instructions stored therein; a communications interface configured to receive data from one or more capacitance sensors; and a processing circuit, the processing circuit configured to execute the instructions to receive data from the one or more capacitance sensors via the communications interface indicative of a capacitance of body tissue at a potential injection site of the patient's body as measured by the one or more capacitance sensors, store the received data indicative of the capacitance in memory, and determine an expected pain level that the patient will experience from an anticipated injection at the potential injection site based on the received data indicative of the capacitance. 12. The processing device according to aspect 11, wherein the measuring device is a drug delivery device containing a drug. 13. The processing device of aspect 11 or 12, further comprising a display screen, wherein the processing circuitry is further configured to present an indication of the determined predicted pain level to the user via the display screen. 14. The processing device of aspect 13, wherein the indicator includes a color-coded diagram of at least a portion of the human body. 15. The processing device of any one of aspects 11 to 14, wherein the processing circuitry is further configured to generate an indication of an overall suitability of the potential injection site based on both (i) the determined expected pain level and (ii) a pre-programmed expected level of pharmaceutical effect that the patient would experience from an expected injection at the potential injection site. 16. The processing device of any one of aspects 11 to 15, wherein the processing circuitry is further configured to solicit and receive user input from the patient indicating at least one of a pain level actually experienced by the patient at the time of actual injection at the potential injection site and a pain level actually experienced by the patient at a pre-programmed time after the time of actual injection. 17. A processing device according to aspect 16, wherein the preprogrammed time is not less than 1 hour after the actual injection and not more than 3 hours after the actual injection. 18. The processing device of aspect 16 or 17, wherein the processing circuitry is further configured to modify the determined expected pain level based on previously received user input. 19. The processing device of aspect 13, wherein the potential injection site is a first potential injection site, the processing circuitry is further configured to receive data indicative of capacitance of body tissue at a second potential injection site measured by one or more capacitance sensors, and the presented indication includes an indication of whether an expected pain level that the patient would experience from an expected injection at the first potential injection site is expected to be greater or less than an expected pain level that the patient would experience from an expected injection at the second potential injection site. 20. A system for evaluating an injection site on a patient's body, the system comprising: an injection device comprising a needle for delivering a medication to the patient via injection, one or more capacitance sensors, and a wireless transmitter; and an external device comprising a memory storing instructions, a communications interface configured to receive data from the wireless transmitter of the injection device, and a processing circuit, the processing circuit being configured to execute the instructions to receive, via the communications interface, data from the injection device indicative of capacitance of body tissue at a potential injection site on the patient's body as measured by the one or more capacitance sensors, store the received data indicative of the capacitance in a memory, and determine an expected pain level that the patient will experience from an anticipated injection with the injection device at the potential injection site based on the received data indicative of the capacitance. 21. The system of aspect 20, wherein the external device further comprises a display screen, and the processing circuitry is further configured to present an indication of the determined predicted pain level to the user via the display screen. 22. The system of aspect 20 or 21, wherein the processing circuitry is further configured to receive, via the communication interface, data from the injection device indicating an actual delivered injection and an actual injection site associated with the actual delivered injection, and to associate the actual injection site with a log entry for the actual delivered injection, the log entry including at least one of a time and a date associated with the actual delivered injection. 23. The system of aspect 22, wherein the processing circuitry is further configured to solicit and receive user input from the patient indicating at least one of the pain level actually experienced by the patient at the time of the actual delivered injection at the actual injection site and the pain level actually experienced by the patient at a pre-programmed time after the time of the actual injection, and to associate the received user input with a log entry for the actually delivered injection. 24. The system of aspect 23, wherein the processing circuitry is further configured to modify the determined expected pain level based on previously received user input. 25. The system of any one of aspects 20 to 24, wherein the injection device further comprises a reservoir for holding the medication.

Claims

1. 1. A method for assessing an injection site on a patient's body, the method comprising: receiving, in a processing circuit in communication with one or more capacitance sensors positioned at a potential injection site on the patient's body, a signal indicative of a capacitance of body tissue at the potential injection site measured by the one or more capacitance sensors; determining, by the processing circuitry based on the received signals, an expected level of pain that the patient will experience from an anticipated injection at the potential injection site.

2. 10. The method of claim 1, wherein the one or more capacitance sensors are disposed on a drug delivery device containing a drug, and the processing circuit is disposed in a mobile device in wireless communication with the drug delivery device.

3. 3. The method of claim 1 or 2, further comprising presenting, by the processing circuitry, an indication of the determined predicted pain level to the user via at least one of a visual indication from a light emitting diode (LED), a visual indication on a display screen, an audible indication, and a tactile indication.

4. The method of claim 3 , wherein the indicia includes a color-coded diagram of at least a portion of a human body on the display screen.

5. 3. The method of claim 1 or 2, further comprising generating, by the processing circuitry, an overall suitability indicator of the potential injection site based on both (i) the determined expected pain level and (ii) a pre-programmed expected level of pharmaceutical effect that the patient would experience from the anticipated injection at the potential injection site.

6. 3. The method of claim 1 or 2, further comprising receiving, in the processing circuitry, a user input from the patient indicating at least one of a pain level actually experienced by the patient at a time of actual injection at the potential injection site and a pain level actually experienced by the patient at a pre-programmed time after the time of the actual injection.

7. 7. The method of claim 6, wherein the preprogrammed time is greater than or equal to 1 hour after the actual injection and less than or equal to 3 hours after the actual injection.

8. The method of claim 6 , further comprising revising the determined expected pain level based on previously received user input.

9. The potential injection site is a first potential injection site, and the method comprises: receiving, in the processing circuit, a signal indicative of a capacitance of body tissue at a second potential injection site on the body of the patient as measured by the one or more capacitance sensors; 4. The method of claim 3, wherein the provided indication includes an indication of whether the expected pain level the patient would experience from the anticipated injection at the first potential injection site is expected to be greater or less than the expected pain level the patient would experience from the anticipated injection at the second potential injection site.

10. 10. The method of claim 9, further comprising injecting a medication into one of the first potential injection site and the second potential injection site based on the provided indication.

11. 1. A processing device for assessing an injection site on a patient's body, said processing device comprising: A memory storing instructions; a communications interface configured to receive data from the one or more capacitive sensors; a processing circuit that executes the instructions to receiving data from the one or more capacitance sensors via the communications interface indicative of a capacitance of body tissue at a potential injection site on the body of the patient as measured by the one or more capacitance sensors; storing the received data indicative of the capacitance in the memory; and a processing device configured to determine an expected level of pain that the patient will experience from an anticipated injection at the potential injection site based on the received data indicative of the capacitance.

12. The processing device of claim 11 , wherein the one or more capacitance sensors are disposed on a drug delivery device containing a drug.

13. 13. The processing device of claim 11 or 12, further comprising a display screen, the processing circuitry being further configured to present an indication of the determined predicted pain level to a user via the display screen.

14. The processing device of claim 13 , wherein the indicia includes a color-coded diagram of at least a portion of a human body.

15. 13. The processing device of claim 11 or 12, wherein the processing circuitry is further configured to generate an overall suitability indicator of the potential injection site based on both (i) the determined expected pain level and (ii) a pre-programmed expected level of pharmaceutical effect that the patient would experience from the anticipated injection at the potential injection site.

16. 13. The processing device of claim 11 or 12, wherein the processing circuitry is further configured to solicit and receive user input from the patient indicating at least one of a pain level actually experienced by the patient at a time of actual injection at the potential injection site and a pain level actually experienced by the patient at a pre-programmed time after the time of the actual injection.

17. 17. The processing device of claim 16, wherein the preprogrammed time is greater than or equal to 1 hour after the actual injection and less than or equal to 3 hours after the actual injection.

18. 17. The processing device of claim 16, wherein the processing circuitry is further configured to modify the determined expected pain level based on previously received user input.

19. the potential injection site is a first potential injection site; the processing circuitry is further configured to receive data indicative of a capacitance of body tissue at a second potential injection site measured by the one or more capacitance sensors; 14. The processing device of claim 13, wherein the presented indication includes an indication of whether the expected pain level the patient would experience from the expected injection at the first potential injection site is expected to be greater or less than the expected pain level the patient would experience from the expected injection at the second potential injection site.

20. 1. A system for assessing an injection site on a patient's body, the system comprising:

1. An injection device comprising: a needle for delivering a medication to the patient via injection; one or more capacitive sensors; an injection device comprising: an external device, A memory storing instructions; a communication interface configured to receive data from the wireless transmitter of the injection device; and a processing circuit that executes the instructions to receiving, via the communication interface, data from the injection device indicative of the capacitance of body tissue at a potential injection site on the body of the patient as measured by the one or more capacitance sensors; storing the received data indicative of the capacitance in a memory; and and determining an expected level of pain that the patient will experience from an anticipated injection with the injection device at the potential injection site based on the received data indicative of the capacitance.

21. 21. The system of claim 20, wherein the external device further comprises a display screen, and the processing circuitry is further configured to present an indication of the determined predicted pain level to a user via the display screen.

22. The processing circuitry includes: receiving data from the injection device via the communication interface indicative of an actual delivered injection and an actual injection site to which the actual delivered injection was delivered; and 22. The system of claim 20 or 21, further configured to add the actual injection site to a log entry for the actual delivered injection, the log entry including at least one of a time and date that the actual delivered injection was delivered.

23. The processing circuitry includes: soliciting and receiving user input from the patient indicating at least one of a pain level actually experienced by the patient at the time of the actual delivered injection at the actual injection site and a pain level actually experienced by the patient at a pre-programmed time subsequent to the time of the actual injection; and 23. The system of claim 22, further configured to update the log entry of the actual delivered injection with the received user input.

24. 24. The system of claim 23, wherein the processing circuitry is further configured to modify the determined expected pain level based on previously received user input.

25. 22. The system of claim 20 or 21, wherein the injection device further comprises a reservoir for holding the medicament.

Images