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EP-4536325-B1 - AN ENERGY HARVESTING SUBASSEMBLY OF A MEDICAMENT DELIVERY DEVICE

EP4536325B1EP 4536325 B1EP4536325 B1EP 4536325B1EP-4536325-B1

Inventors

  • SÄLL, Daniel

Dates

Publication Date
20260506
Application Date
20230526

Claims (15)

  1. A subassembly (2) of a medicament delivery device (1), the subassembly comprising: a housing (3) extending along a longitudinal axis (5) and having a proximal end (3a) and distal end (3b); a rear cap (13) arranged inside the housing at the distal end, the rear cap comprising a flexible arm (16) that is flexible in a radial direction perpendicular to the longitudinal axis, the flexible arm comprising a protrusion (12); a U-bracket (14) arranged radially inside the rear cap (13) and extending from a distal end (17a) of an inner space of the rear cap to a proximal end (17b) of the rear cap, the U-bracket (14) comprising at least one distally facing surface (20) on its proximal end (22) that abuts against a respective proximally facing surface (24) of the rear cap (13), and wherein a distal end (26) of the U-bracket is spaced apart from the rear cap by a gap (28); a plunger rod (30) arranged radially inside the U-bracket, the plunger rod comprising a proximally facing surface (32) that abuts against a distally facing surface (34) of the protrusion of the rear cap; a spring (36) arranged radially inside the plunger rod, the spring is compressed by a distally facing surface (40) of the plunger rod and a proximally facing surface (43) of the U-bracket; a piezo-electric energy harvesting unit (46) arranged distally with respect to the rear cap (8) and comprising a first member (50a) being movable with respect to a second member (50b) for generating electrical energy, the first member (50a) being arranged adjacent the rear cap so that, when the spring (36) is released, the spring force acts on the U-bracket to close the gap (28) to cause the first member to move in relation to the second member; and a power management unit (54) configured to harvest the electrical energy generated when the first member moves in relation to the second member and to provide the electrical energy to a data transmission device (56).
  2. The subassembly according to claim 1, the piezo-electric energy harvesting unit being arranged in a rear lid (60) attached to the distal end of the housing.
  3. The subassembly according to claim 2, wherein a diameter of the first member is substantially equal to an inner diameter of the lid housing the first member and the second member.
  4. The subassembly according to any one of the preceding claims, wherein the rear cap comprises a pin (66) extending from the distal end of the rear cap towards the first member.
  5. The subassembly according to claim 4, wherein the pin is attached to a flexible portion (68) of the rear cap.
  6. The subassembly according to any one of claims 4 and 5, wherein when the spring is released, the spring force acts on the U-bracket to close the gap and impact on a surface (70) of the rear cap, whereby the pin is caused to impact on the first member.
  7. The subassembly according to claim 6, wherein the U-bracket is configured to bounce on the surface of the rear cap multiple times.
  8. The subassembly according to any one of the preceding claims, wherein the at least one distally facing surface (20) of the U-bracket are comprised in a respective radially extending protrusion (72).
  9. The subassembly according to any one of the preceding claims, comprising a guide rod (76) arranged radially inside the spring, the guide rod comprising a flange (78) on its distal end that abuts against the distal end (80) of the spring and a distal end of the U-bracket.
  10. The subassembly according to any one of the preceding claims, wherein the at least one distally facing surface (20) of the U-bracket are inclined with respect to the longitudinal axis.
  11. The subassembly according to anyone of the preceding claims, wherein when the plunger rod is moved proximally in relation to the U-bracket the spring is released and decompressed, and when the plunger rod reaches to a position where the plunger rod is outside the U-bracket, the U-bracket is radially compressed so that the distally facing surface of the U-bracket is moved away from the proximally facing surface of the rear cap to be movable in the distal direction under the influence of a force from the spring.
  12. The subassembly according to anyone of the preceding claims, wherein the first member (50a) is a piezo electric membrane being movable with respect to the second member (50b) being a support for the first member (50a).
  13. The subassembly according to anyone of the preceding claims, wherein when the spring is released, a click sound is generated by an impact of a distally facing surface (43) of the U-bracket and a proximally facing surface (70) of the rear cap.
  14. The subassembly according to anyone of the preceding claims, wherein the data transmission device includes a Bluetooth transmitter.
  15. A medicament delivery device (1) comprising the subassembly according to any one of the preceding claims.

Description

TECHNICAL FIELD The present disclosure generally relates to medicament delivery devices such as autoinjectors, and particularly concerns a subassembly adapted to provide digital confirmation of a completed injection. BACKGROUND A number of medical conditions require injections. These days, a number of different injection devices exist, including various types of pen injectors, autoinjectors and on-body devices. Although many of these devices have enabled major improvements in the management of a number of medical conditions, various limitations do still exist in the current technology. Not least amongst these are the difficulties faced by patients that require frequent injections and by patients that need to inject particularly viscous drugs. In considering these problems, the applicant has appreciated that various developments could be made to help improve the medicament delivery devices on the market today. For example, the injection devices on the market are typically only used once before being disposed of which is not preferable from a sustainability point of view. Prior art injection devices are disclosed in WO 2016/055305 A1 and EP 3 326 671 A1. SUMMARY An object of the present disclosure is to provide a subassembly for a medicament delivery device which solves, or at least mitigates problems of the prior art. According to a first aspect of the present disclosure, there is provided a subassembly of a medicament delivery device, the subassembly comprising: a housing extending along a longitudinal axis and having a proximal end and distal end; a rear cap arranged inside the housing at the distal end, the rear cap comprising a flexible arm that is flexible in a radial direction perpendicular to the longitudinal axis, the flexible arm comprising a protrusion; a U-bracket arranged radially inside the rear cap and extending from a distal end of an inner space of the rear cap to a proximal end of the rear cap, the U-bracket comprising at least one distally facing surface on its proximal end that abuts against a respective proximally facing surface of the rear cap, and wherein a distal end of the U-bracket is spaced apart from the rear cap by a gap; a plunger rod arranged radially inside the U-bracket, the plunger rod comprising a proximally facing surface that abuts against a distally facing surface of the protrusion of the rear cap; a spring arranged radially inside the plunger rod, the spring is compressed by a distally facing surface of the plunger rod and a proximally facing surface of the U-bracket; a piezo-electric energy harvesting unit arranged distally with respect to the rear cap and comprising a first member being movable with respect to a second member for generating electrical energy, the first member being arranged adjacent the rear cap so that, when the spring is released, the spring force acts on the U-bracket to close the gap to cause the first member to move in relation to the second member; and a power management unit configured to harvest the electrical energy generated when the first member moves in relation to the second member and to provide the electrical energy to a data transmission device. Embodiments of the present disclosure advantageously provide for harvesting electrical energy from the motion of the U-bracket as it impacts on the rear cap. When the U-bracket hits the rear cap, the impact force is transferred to the first member of the piezo-electric energy harvesting unit so that it moves with respect to the second member of the piezo-electric energy harvesting unit. This allows energy to be harvested by the piezo-electric energy harvesting unit which can be used for powering the data transmission device to send a digital confirmation of an injection to a receiver hub or an external receiver device. Such digital confirmation includes for example a time stamp and serial number of the injector. In the present disclosure, when the term "distal direction" is used, this refers to the direction pointing away from the dose delivery site during use of the medicament delivery device. When the term "distal part/end" is used, this refers to the part/end of the delivery device, or the parts/ends of the components thereof, which under use of the medicament delivery device is/are located furthest away from the dose delivery site. Correspondingly, when the term "proximal direction" is used, this refers to the direction pointing towards the dose delivery site during use of the medicament delivery device. When the term "proximal part/end" is used, this refers to the part/end of the delivery device, or the parts/ends of the members thereof, which under use of the medicament delivery device is/are located closest to the dose delivery site. Further, the term "longitudinal", "longitudinally", "axially" or "axial" refer to a direction extending from the proximal end to the distal end, typically along the device or components thereof in the direction of the longest extension of the device and/or co