Injection Apparatus

Abstract

An injection apparatus (2) comprising a housing (4) and an injector sub-assembly (6), wherein the injector sub-assembly is located within the housing; the injector sub-assembly includes a needle (20), a syringe barrel (18) and a piston (40) located within the syringe barrel; the injector sub-assembly is slidably mounted within the housing between an operative configuration in which at least a portion of the needle projects from the housing, and a retracted configuration in which the injector sub assembly is wholly located within the housing; and wherein the housing includes a housing body and needle exit door (44) pivotally connected to the body such that the door closes a needle exit aperture defined by the housing body when the injector sub-assembly is in its retracted configuration and opens when the injector sub-assembly is in its operative configuration to permit the needle to exit the housing.

Claims

1. An injection apparatus comprising a housing and an injector sub-assembly, wherein the injector sub-assembly is located within the housing; the injector sub-assembly includes a needle, a syringe barrel and a piston located within the syringe barrel; the injector sub-assembly is slidably mounted within the housing between an operative configuration in which at least a portion of the needle projects from the housing, and a retracted configuration in which the injector sub assembly is wholly located within the housing; and wherein the housing includes a housing body and needle exit door pivotally connected to the housing body such that the door closes a needle exit aperture defined by the housing body when the injector sub-assembly is in its retracted configuration and opens when the injector sub-assembly is in its operative configuration to permit the needle to exit the housing.

2. An injection apparatus according to claim 1, wherein the needle exit door is operatively coupled to the injector sub-assembly such that the door is moved from a closed configuration to an open configuration as the injector sub-assembly moves from its retracted configuration to its operative configuration.

3. An injection apparatus according to claim 1, wherein the apparatus further includes an assembly drive motor which drives the injector sub assembly to move between its retracted and operative configurations.

4. An injection apparatus according to claim 3, wherein the drive motor is an electric drive motor and the injection apparatus further includes one or more batteries located within the housing, wherein the drive motor is powered by the or each battery.

5. An injection apparatus according to claim 3, wherein the injection apparatus further includes a drive transmission disposed between the drive motor and the injector sub-assembly.

6. An injection apparatus according to claim 5, wherein the drive transmission includes an external screw thread and one or more threaded elements which engage with the external screw thread.

7. An injection apparatus according to claim 6, wherein the or each threaded element is carried by the injector sub-assembly and the screw thread is carried externally by an output shaft from the motor, whereby rotation of the screw thread by the motor causes the injector sub-assembly to move linearly within the housing.

8. An injection apparatus according to claim 1, wherein the injector sub-assembly further includes a dose motor which is operatively connected to the piston located within the syringe barrel, whereby the piston is urged to move axially within the syringe barrel when the dose motor rotates.

9. An injection apparatus according to claim 8, wherein the injector sub-assembly further includes a dose transmission disposed between the dose motor and the piston, wherein the piston is driven by the motor via the dose transmission.

10. An injection apparatus according to claim 8, wherein the dose motor is an electric motor; the injection apparatus includes one or more batteries located within the housing; and the dose motor is powered by the or each battery.

11. An injection apparatus according to claim 8, wherein the apparatus further includes a dose input component, wherein the displacement of the piston within the syringe barrel is determined by the dose input component.

12. An injection apparatus according to claim 11, wherein the apparatus includes a controller, wherein the controller includes an input which is operatively connected to the dose input component; the controller includes an output which is operatively connected to the dose motor; and the controller converts data input via the dose input component to an output signal which controls the operation of the dose motor.

13. An injection apparatus according to claim 1, wherein the apparatus includes a safety sensor, wherein the safety sensor prevents movement of the injector sub-assembly from its retracted configuration to its operative configuration if a pre-determined condition measured by the sensor is not met.

14. An injection apparatus according to claim 13, wherein the safety sensor comprises a skin contact sensor and the pre-determined condition is contact of the sensor with the skin of a user.

15. An injection apparatus according to claim 1, wherein the apparatus includes a memory which stores data relating to previous uses of the apparatus.

16. An injection apparatus according to claim 15, wherein the data includes the time since the previous use of the apparatus and/or the previous dose dispensed by the apparatus.

17. An injection apparatus according to claim 15, wherein the syringe barrel contains a pre-determined number of doses of a liquid pharmaceutical composition and the memory further includes data relating to the number of doses of the composition remaining in the syringe barrel.

18. An injection apparatus according to claim 1, wherein the apparatus further includes an operation lock which has a locked configuration in which movement of the injector sub-assembly from its retracted configuration to it operative configuration is prevented and an unlocked configuration in which the movement of the injector sub-assembly from its retracted configuration to its operative configuration is permitted.

19. An injection apparatus according to claim 1, wherein the apparatus includes a biasing element or a control element which returns the injector sub-assembly to its retracted configuration after each use or after a pre-determined period of time.

20. An injection apparatus according to claim 19, wherein the apparatus further includes an operation lock which has a locked configuration in which movement of the injector sub-assembly from its retracted configuration to it operative configuration is prevented and an unlocked configuration in which the movement of the injector sub-assembly from its retracted configuration to its operative configuration is permitted; and wherein the biasing element or the control element configures the operation lock in its locked configuration when it returns the injector sub-assembly to its retracted configuration.

21. An injection apparatus according to claim 1, wherein the housing body defines a window through which the syringe barrel is visible.

22. An injection apparatus according to claim 1, wherein the apparatus further includes a plurality of pins located adjacent to the needle exit aperture, wherein the apparatus further includes a vibrator which vibrates the pins when activated.

23. An injection apparatus according to claim 1, wherein the apparatus further includes a near field communication transceiver.

Description

[0056] An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings in which:

[0057] FIG. 1 shows a cross-section through an injection apparatus according to the invention in its retracted configuration;

[0058] FIG. 2 shows a cross-section through the injection apparatus shown in FIG. 1 when in its operative configuration;

[0059] FIG. 3 shows a cross-section through the injector sub-assembly which forms a part of the invention as shown in FIGS. 1 and 2;

[0060] FIG. 4 shows a front elevational view of the injection apparatus shown in FIG. 1; and

[0061] FIG. 5 shows a refill cartridge for use with the injection apparatus.

[0062] For the avoidance of doubt, the skilled person will appreciate that in this specification, the terms “up”, “down”, “front”, “rear”, “upper”, “lower”, “width”, etc. refer to the orientation of the components as found in the example when installed for normal use as shown in the Figures.

[0063] FIGS. 1 and 2 show a cross-section through an injection apparatus 2 according to the invention. The apparatus 2 comprises a housing body 4 within which is located an injector sub-assembly 6 (shown by itself in FIG. 3), an assembly drive motor 8 and four “AAA” size batteries 10.

[0064] The injector sub-assembly 6 includes a body 12 which defines a first recess 14 that is shaped and configured to receive therein a conventional insulin cartridge 16 (shown in FIG. 5) which includes a syringe barrel 18 and a needle 20. The body 12 also defines a second recess 22, within which is located a dose motor 24, and a third recess 26 within which is located a dose transmission 28.

[0065] The dose motor 24 is powered by the batteries 10 and is controlled by a primary processor (not shown). The primary processor is a conventional processor which energises the motor 24 for a period of time that is sufficient to deliver the desired dose of a medicament stored within the syringe barrel 18.

[0066] The dose transmission includes a first spur gear 30, an intermediate spur gear 32 and a driven spur gear 34, wherein the first spur gear 30 is driven by the dose motor 24 and is meshed with the intermediate spur gear 32, and the intermediate spur gear 32 is meshed with the driven spur gear 34 such that rotation of the first spur gear 30 by the dose motor 24 is transmitted to the driven spur gear 34 via the intermediate spur gear 32. The driven spur gear 34 drives a conventional telescopic screw jack 36 which in turn drives a piston contact end 38 of the screw jack 36 in a linear direction, which is up and down as shown in FIGS. 1 and 2.

[0067] The transmission further includes a rotation sensor (not shown) which senses the rotation of the driven spur gear 34. The rotation of the driven spur gear equates to a corresponding linear motion of the piston contact end 38 of the screw jack 36, which in turn corresponds to a swept volume of the syringe barrel 18. The rotation sensor feeds back to the primary processor which controls the dose motor 24 such that the desired dose is ejected from the syringe.

[0068] The piston contact end 38 of the telescopic screw jack 36 engages a piston 40 disposed within the syringe barrel 18, the piston 40 forming part of the conventional insulin cartridge 16.

[0069] The injector sub-assembly 6 further includes a downwardly projecting leg 42 which is operatively connected to a needle exit door 44. The needle exit door is pivotally connected to the housing body 4 such that it is able to pivot about a fulcrum 46. As the injector sub-assembly 6 moves downwards, it causes the needle exit door 44 to pivot about the fulcrum 46. The needle exit door 44 defines therein an opening (not shown) which aligns with the needle 20 as the injector sub-assembly 6 moves downwards and the needle exit door 44 pivots about the fulcrum 46. However, when the injector sub-assembly 6 is in its fully retracted configuration, as shown in FIG. 1, the opening in needle exit door 44 is out of alignment with the needle 20 such that the needle 20 is covered by the needle exit door 44 and the interior of the housing 4 is essentially closed against the ingress of foreign particulate matter.

[0070] The injector sub-assembly 6 is able to move linearly within the housing 4 (in an up and down direction as shown in FIGS. 1 and 2). This linear movement is driven and controlled by the assembly drive motor 8.

[0071] A shaft 50 which defines an outer helical thread is secured to the output shaft of the assembly drive motor 8. Corresponding threaded elements (not shown) are provided on a distal end of an arm 52 which projects from the injector sub-assembly 6, such that the threaded elements of the arm 52 mesh with the outer helical thread of the shaft 50. In this way, the threaded elements carried by the arm 52 and the threaded shaft 50 together form a pseudo “rack and pinion” type transmission arrangement, which converts the rotational motion of the shaft 50 when driven by the assembly drive motor 8 to a linear motion of the injector sub-assembly 6. The skilled person will appreciate that instead of the “open” threaded elements, the arm 52 may carry at its distal end a captive nut through which the shaft 50 passes.

[0072] The apparatus 2 further includes a secondary processor (not shown) and an assembly drive motor control circuit (also not shown). The primary processor and the secondary processor are both connected to the drive motor control circuit and the drive motor control circuit will only energise the assembly drive motor 8 if positive control signals are received from both the primary and secondary processors. A similar arrangement is provided for the dose motor 24. Accordingly, the secondary processor acts as a failsafe or watchdog for the primary processor to ensure the safe operation of the apparatus 2.

[0073] At the top of the housing body 4 is an “inject” button 54 which activates the dose motor 24 if the processor has determined that all relevant safety conditions have been met.

[0074] One of the safety conditions is sensed by a skin contact sensor 56 located at the bottom of the housing body 4. The skin contact sensor 56 comprises a capacitive sensor element which is configured to sense contact with skin. The skin contact sensor is electrically connected to an input of the processor, and the processor is programmed not to permit operation of the assembly drive motor 8 or the dose motor 24 unless the skin contact sensor 56 is in contact with a portion of skin 1 of the patient.

[0075] FIG. 3 shows the injector sub-assembly 6 by itself.

[0076] FIG. 4 shows a front view of the apparatus 2. On the front of the housing body 4 is provided an on/off button 58, a dose increase button 60 and dose decrease button 62. In order to activate the apparatus 2, the patient must first press the on/off button 58. Thus, the on/off button 58 forms an operation lock for the apparatus 2. The patient then selects the desired dose of the medicament (e.g. insulin) using either the dose increase button 60 or the dose decrease button 62. The selected dose is displayed on a display screen 64 located on the front of the housing body 4. The display screen 64 also displays the last dose that was administered by the apparatus 2 and the elapsed time since the last dose.

[0077] So that the patient has a visible indication of the number of doses remaining in the syringe barrel 18, an elongate window 66 is provided on the front face of the housing body 4 such that the window 66 overlies the syringe barrel 18 located within the housing body 4.

[0078] It is necessary periodically to replace the insulin cartridge 16, or the needle 20. Accordingly, a hinged cover 68 is provided over a portion of the first recess 14 which permits access to the recess 14 and the insulin cartridge 16 located therein. When the hinged cover 68 is rotated away from the housing body 4, the patient is able to access the needle 20 carried by the cartridge 16 or, if desired, to remove the cartridge 16 in its entirety from the first recess 14.

[0079] The apparatus 2 shown in FIG. 4 further includes a near field communications transceiver 70, which is powered by the batteries 10 and which is able to communicate with devices implanted under the skin of a patient, such as a continuous glucose monitoring implant, for example the Freestyle Libre™. The NFC transceiver may also communicate with mobile devices to transfer operational data (such a historical data relating to amounts of medicament injected and when the injection events occurred) for patient records.

[0080] The apparatus 2 further includes a ring of gate control pins 72 located around the needle exit aperture (i.e. the aperture defined through the housing 4, through which the needle 20 passes when in use). The gate control pins 72 are connected to a vibrator (not shown), which in turn is controlled by the primary processor, such that the pins apply a vibrating force to the patient's skin adjacent to the injection site immediately prior to the needle 20 exiting the housing. As noted above, this decreases the pain signals associated with the injection event.

[0081] The insulin cartridge 16 is shown in more detail in FIG. 5. Suitable cartridges 16 are commercially available, for example, the Penfill 3 mL insulin cartridge from Novo Nordisk. The cartridge 16 comprises a syringe barrel 18 and a needle 20. The needle 20 forms part of a needle assembly 80 which comprises a threaded connector portion 82, a needle boss 84 which extends from the threaded connector portion 82 and the needle 20 which is secured to the needle boss 84.

[0082] The threaded connector portion 82 threadedly engages a corresponding thread formed a distal end of the syringe barrel 18 in order to secure the needle 20 to the syringe barrel 18. The syringe barrel also includes the piston 40 which forms a liquid-tight seal with an interior surface of the syringe barrel 18. The proximal end of the syringe barrel 18 is open in use to permit access to the piston 40 by the piston contact end 38 of the telescopic screw jack 36.

[0083] When a new cartridge 16 is inserted into the apparatus 2, the apparatus enters an “airshot” mode, which permits the dose motor 24 to operate for a short period of time without the apparatus 2 being in contact with the skin or the needle being expose in order to purge any air from the syringe barrel 18.

[0084] In use, a patient removes the operation lock by pressing and holding the on/off button 58 until the device powers-up. The patient then enters the desired dose of the medicament (e.g. insulin) using the dose increase button 60 or the dose decrease button 62. The selected dose is displayed on the display screen 64. The patient then exposes a portion of skin at the desired injection site, contacts the skin with the bottom of the housing body 4 and presses the inject button 54.

[0085] The skin contact sensor 56 senses that the housing body 4 is in contact with a portion of skin and sends a signal to the primary and secondary processors to confirm that this necessary condition for safe operation of the apparatus 2 is met. The processors then send a positive control signal to the drive motor control circuit and the assembly drive motor 8 is energised, which in turn rotates the threaded shaft 50. The engagement between the threaded shaft 50 and the threaded elements carried by the arm 52 of the injector sub-assembly 6 cause the injector sub assembly to move linearly downwards towards the bottom of the housing body 4. The downward movement of the injector sub-assembly also causes the needle exit door 44 to open as a result of the connection between the leg 42 of the injector sub-assembly 6 and the needle exit door 44, and the pivotal coupling of the needle exit door 44 about the fulcrum 46. The opening of the needle exit door 44 by the downward movement of the injector sub-assembly 6 permits the needle 20 to project through the needle outlet aperture, beyond the bottom of the housing body 4 and through the skin 1 of the patient.

[0086] When the injector sub-assembly 6 is in its operative configuration (i.e. the injector sub-assembly has reached the end of its downward travel), the drive motor control circuit then interrupts the power to the assembly drive motor 8. The primary and secondary processors then send a control signal to the dose motor 24 which is energised and drives the piston 40 disposed within the syringe barrel 18 downwards by a predetermined distance via the dose transmission 28. The processors calculates the volume of the medicament to be dispensed based on the desired dose of the medicament. It then calculates the required displacement of the piston to dispense the calculated volume of the medicament, and finally it calculates the corresponding rotation of the driven spur gear 34 required to displace the piston by the desired distance. The primary and secondary processors control the dose motor 24 such that it is energised until the driven spur gear 34 has completed the calculated rotation or rotations, as sensed by the dose sensor, after which the dose motor 24 is disconnected from the electrical power source provided by the batteries 10.

[0087] In an alternative embodiment (not shown), the apparatus 2 includes a dose sensor which either directly senses displacement of the piston 40 or which indirectly senses displacement of the piston 40 via the rotation of a different component of the dose transmission 28. The processor is able to determine the volume of the medicament that has been ejected from the apparatus based on the displacement of the piston 40, as sensed by the dose sensor. The processor controls the power supplied to the dose motor 24 in response to the displacement of the piston as sensed by the dose sensor.

[0088] After the power to the dose motor 24 has been interrupted, the primary and secondary processors control the assembly drive motor 8 to rotate in the opposite sense to the previous operation such that the injector sub-assembly 6 is driven upwards. This upward movement of the injector sub-assembly 6 retracts the needle 20 from the skin 1 of the patient and closes the needle exit door 44.

[0089] Once the injector sub assembly 6 is in its retracted configuration, the operative lock is re-engaged whereby the apparatus 2 can only be re-activated when the user presses and holds the on/off button 58 once again. The data displayed on the display screen in connection with the previous dose and the time since the previous dose was administered is then updated.

[0090] It will be appreciated that the only actions required by the user in order to effect the administration of the medicament within the syringe barrel 18 are to switch the device on, select the desired dose, hold the device against a portion of skin and press the inject button 54.