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EP-3697477-B1 - MEDICAMENT DELIVERY DEVICE WITH OPTICAL SENSOR

EP3697477B1EP 3697477 B1EP3697477 B1EP 3697477B1EP-3697477-B1

Inventors

  • HELMER, MICHAEL
  • REHBEIN, CHRISTIAN

Dates

Publication Date
20260506
Application Date
20181019

Claims (15)

  1. A medicament delivery device (20, 40, 60, 70) comprising: a housing (22) configured to receive a container of medicament; a piston rod (23) moveable within the housing (22) and configured to engage a container of medicament when received within the housing (22); and a position-sensing mechanism (25) configured to detect the position of the piston rod (23) within the housing (22), the position-sensing mechanism (25) comprising: a light source (28) configured to emit light; a sensor (29) disposed proximate the light source (28) and configured to receive light emitted by the light source (28); and a blocking member (24, 26, 41, 51, 66) being moveable between the light source (28) and the sensor (29) in dependence upon movement of the piston rod (23) and configured to block light emitted by the light source (28) and prevent said light reaching the sensor (29); wherein the position-sensing mechanism (25) is configured such that a varying light pattern reaches the sensor (29) dependent on the position of the blocking member (26) relative to the light source (28) and the sensor (28); and wherein the sensor (29) is configured to detect the light pattern received to determine the position of the piston rod (23) within the housing (22), wherein a particular pattern is associated with one position of the piston rod (23) within the housing (22), characterized in that : the blocking member extends radially relative to the piston rod.
  2. The medicament delivery device (20, 40) according to claim 1, further comprising a projecting member (24) extending from the piston rod (23), the projecting member (24) having a surface (27) configured such that a distance from the surface (27) to a longitudinal axis of the piston rod (23) varies along the length of the piston rod (23).
  3. The medicament delivery device (20, 40) according to claim 2, wherein the surface (27) of the projecting member (24) is inclined relative to the direction of movement of the piston rod (23) in the housing (22).
  4. The medicament delivery device (20, 40, 60, 70) according to any one of the preceding claims, wherein the piston rod (23) is threadingly engaged with a drive mechanism (31) and is configured to act upon a piston (14) of a container of medicament when received within the medicament delivery device (20, 40) when the drive mechanism (31) is activated.
  5. The medicament delivery device (20) according to any one of claim 2 to claim 3 or claim 4 when dependent on claim 2, wherein the projecting member (24) is the blocking member (26) and is configured to be moveable between the light source (28) and the sensor (29).
  6. The medicament delivery device (60, 70) according to claim 4, wherein the blocking member (26) extends from a component (23) on the opposite side of the drive mechanism (31) to the piston rod (23), and the component (23) is engaged with the drive mechanism (31) such that it is moveable within the housing (22) when the drive mechanism (31) is activated.
  7. The medicament delivery device (70) according to claim 6, wherein the position-sensing mechanism (25) and the component (23) are located in a separable portion of the housing (22) and the drive mechanism (31) comprises a separable connection (64) which is configured to separably connect a part of the drive mechanism (31) which engages the piston rod (23) in a first portion (67) of the housing and a part of the drive mechanism that engages the component (23) in a second portion (68) of the housing.
  8. The medicament delivery device (40) according to claim 2 or any of claim 3 or claim 4 when dependent on claim 2, wherein the blocking member (26) of the position-sensing mechanism (25) comprises a first blocking element (41) that is moveable in a direction perpendicular to the direction in which the piston rod (23) is moveable, the first blocking element (41) being biased into contact with the surface (27) of the projecting member (24), the light source comprising a first light source (28) and the sensor comprising a first sensor (29), the first blocking element (41) comprising a first blocking portion (43) configured such that the first blocking portion (43) is moveable between the first light source (28) and the first sensor (29).
  9. The medicament delivery device (40) according to claim 8, wherein the position-sensing mechanism (25) further comprises a second blocking element (51) located on the opposite side of the piston rod (23) to the first blocking element (51) and having a second blocking portion (53), the light source comprising a second light source (58) and the sensor comprising a second sensor (59), the second blocking element (51) being moveable in a direction perpendicular to the direction in which the piston rod (23) is moveable between the second light source (58) and the second sensor (59), the second blocking element (58) being biased into contact with the body of the piston rod (23) and configured such that a varying light pattern reaches the second sensor (59) from the second light source (58) dependent on the position of the second blocking portion (53) which is dependent on the position of the piston rod (23) in the housing (22).
  10. The medicament delivery device (40) according to claim 9, wherein the first and/or second light source (28, 58) and the first and/or second sensor (29, 59) are arranged such that the first and/or second light source (28, 58) is on a first side of the respective first and/or second blocking element (41, 51) and the first and/or second sensor (29, 59) is on the opposite side of the respective first and/or second blocking element (41, 51).
  11. The medicament delivery device (40) according to any one of claim 8 to claim 10, wherein the first and/or second blocking element (41, 51) comprises an aperture (46, 56) having a cross-sectional area that varies in the direction of movement of the first and/or second blocking element (41, 51) to block different amounts of light dependent on the position of the first and/or second blocking element (41, 51) in the direction of movement of the first and/or second blocking element (41, 51).
  12. The medicament delivery device (40) according to any one of claims 8 to 11, wherein a surface of the first and/or second blocking portion (43, 53) is configured such that a distance from the surface to a longitudinal axis of the piston rod ("3) varies along the surface.
  13. The medicament delivery device (40) according to claim 12, wherein surface of the first and/or second blocking portion (43, 53) is inclined relative to the direction of movement of the first and/or second blocking element (41, 51).
  14. The medicament delivery device (20, 40, 60, 70) according to any one of the preceding claims, further comprising a controller configured to receive a signal from the first and/or second sensor (29, 59) and determine the position of the piston rod (23) in dependence on the received signal and optionally, wherein the controller is configured to output a position signal to a user interface (69) representative of the determined piston rod (23) position.
  15. The medicament delivery device (20, 40, 60, 70) according to any preceding claim, further comprising a container of medicament (36).

Description

Technical Field The present disclosure relates to a medicament delivery device. Background Certain types of injection devices typically have a sealed container of medicament, a needle for injection of the medicament into a patient and a mechanism for dispensing the medicament from the container through the needle. Such dispensing mechanisms can include a plunger or piston which can be moved into the container to dispense the medicament. WO 2015/143058 discloses an apparatus comprising a syringe housing and a plunger slideably received within the syringe housing. The plunger has a substantially opaque portion and a substantially translucent portion. A light sensor module is disposed on the syringe housing having a light sensor housing and a first sensor element and a second sensor element diposed within the sensor housing. When the plunger is in its first position, the translucent portion is aligned with the first sensor element and when the plunger is in its second position, the translucent portion is aligned with the second sensor element. Further examples of the relevant prior art can be found in US4498843A, US2014/194826A1 and JP3381301B2. Summary It is the object of the present disclosure to provide an improved medicament delivery device. According to the present disclosure, there is provided a medicament delivery device comprising a housing configured to receive a container of medicament, a piston rod moveable within the housing and configured to engage a container of medicament when received within the housing, and a position-sensing mechanism configured to detect the position of the piston rod within the housing, the position-sensing mechanism comprising a light source configured to emit light, and a sensor disposed proximate the light source and configured to receive light emitted by the light source, and a blocking member extending radially relative to the piston rod, the blocking member being moveable between the light source and the sensor in dependence upon the movement of the piston rod, wherein the position-sensing mechanism is configured such that a varying light pattern reaches the sensor dependent on the position of the blocking member relative to the light source and the sensor, and wherein the sensor is configured to detect the light pattern received to determine the position of the piston rod within the housing. The medicament delivery device may further comprise a projecting member extending from the piston rod. The projecting member may have a surface that is configured such that a distance from the surface to a longitudinal axis of the piston rod varies along the length of the piston rod. The surface may be inclined relative to the axis of the direction of movement of the piston rod in the housing. The projecting member may extend radially from the piston rod. The inclined surface may be at a radially outermost position of the projecting member. The light source and the sensor may be fixed relative to the housing. The light source and the sensor may be arranged such that the light source is on a first side of the projecting member and the sensor is on the opposite side of the projecting member and the projecting member variably blocks light passing from the light source to the sensor. The housing may comprise a piston rod guide having at least two projections between which the projecting member is located, and the projections may be configured to restrict rotational movement of the piston rod. The piston rod may be engaged with a drive mechanism and may be configured to act upon a piston of a container of medicament when received within the medicament delivery device when the drive mechanism is activated. The projecting member may be the blocking member and may be configured to be moveable between the light source and the sensor. The blocking member may extend from a component on the opposite side of the drive mechanism to the piston rod, and the component may be engaged with the drive mechanism such that it is moveable within the housing when the drive mechanism is activated. The position-sensing mechanism and the component maybe located in a separable portion of the housing and the drive mechanism may comprise a separable connection which is configured to separably connect a part of the drive mechanism which engages the piston rod in a first portion of the housing and a part of the drive mechanism that engages the component in a second portion of the housing. The blocking member of the position-sensing mechanism may comprise a first blocking element that is moveable in a direction perpendicular to the direction in which the piston rod is moveable, and the first blocking element may be biased into contact with the surface of the projecting member, and the light source may comprise a first light source and the sensor may comprise a first sensor, and the first blocking element may comprise a first blocking portion configured such that the first blocking portion is moveable between the