FROST PROTECTED INJECTION DEVICE

• US 20120184917A1
• Filed: 07/08/2010
• Published: 07/19/2012
• Est. Priority Date: 07/08/2009
• Status: Active Grant

• Current Assignee: Novo Nordisk A/S
• Original Assignee: Novo Nordisk A/S
• Inventors: Bom, Lars Morten, Enggaard, Christian Peter, Ostergaard, Brian, Jensen, Jacob Kollerup
• Granted Patent: US 9,616,175 B2
• Time in Patent Office: Days
• US Class Current: 604/187
• CPC Class Codes: A61M 2005/2407 from the rear
• CPC Class Codes: A61M 2005/31508 provided on the piston-rod
• CPC Class Codes: A61M 2005/3152 including gearings to multiply or attenuate the piston displacing force
• CPC Class Codes: A61M 2205/581 by audible feedback
• CPC Class Codes: A61M 2205/583 by visual feedback
• CPC Class Codes: A61M 2205/6081 Colour codes
• CPC Class Codes: A61M 5/24 Ampoule syringes, i.e. syringes with needle for use in combination with replaceable ampoules or carpules, e.g. automatic ampoules or carpules A61J1/06
• CPC Class Codes: A61M 5/2425 by compression of deformable ampoule or carpule wall
• CPC Class Codes: A61M 5/3146 Priming, e.g. purging, reducing backlash or clearance
• CPC Class Codes: A61M 5/315 Pistons; Piston-rods; Guiding, blocking or restricting the movement of the rod or piston; Appliances on the rod for facilitating dosing ; Dosing mechanisms
• CPC Class Codes: A61M 5/31505 Integral with the syringe barrel, i.e. connected to the barrel so as to make up a single complete piece or unit
• CPC Class Codes: A61M 5/31551 including axial movement of dose setting member
• CPC Class Codes: A61M 5/3156 using volume steps only adjustable in discrete intervals, i.e. individually distinct intervals
• CPC Class Codes: A61M 5/3157 Means providing feedback signals when administration is completed A61M5/20 takes precedence
• CPC Class Codes: A61M 5/31585 performed by axially moving actuator, e.g. an injection button
• CPC Class Codes: A61M 5/31593 Multi-dose, i.e. individually set dose repeatedly administered from the same medicament reservoir

Abstract

The invention relates to an injection device (100, 200, 300) which is capable of resisting proximal movements of a piston rod (107, 207, 307) relative to a housing (102, 202, 302), when the piston rod (107, 207, 307) is subjected to proximally directed forces below a threshold magnitude, and of allowing reversible proximal movements of the piston rod (107, 207, 307) relative to the housing (102, 202, 302), when the piston rod (107, 207, 307) is subjected to proximally directed forces of or above the threshold magnitude.

Claims

1. A medical injection device comprising:

a variable volume reservoir containing a liquid drug and comprising an outlet and a movable wall,

an injection mechanism operable to inject a dose of the liquid drug and comprising an actuation member adapted to displace the movable wall in a first direction, and

a coupling mechanism for affecting movements of the actuation member in a second direction,

wherein the injection device is configured to prevent a movement of the actuation member in the second direction in response to a subjection of the actuation member to a first force being of a magnitude which is smaller than a threshold value and to allow a reversible movement of the actuation member in the second direction in response to a subjection of the actuation member to a second force being of a magnitude which is equal to or greater than the threshold value.

2. An injection device according to claim 1, wherein the second force acts on the actuation member via the movable wall.

3. An injection device according to claim 1, wherein the second direction is substantially opposite to the first direction.

4. An injection device according to claim 1, wherein the injection mechanism further comprises a drive arrangement adapted to cause a movement of the actuation member in the first direction.

5. An injection device according to claim 4, wherein the drive arrangement comprises bias means for causing the actuation member to be biased in the first direction, and wherein the injection mechanism is configured to allow the actuation member to move a distance in the second direction in response to the second force and to move the actuation member in the first direction substantially the same distance upon a discontinuation of the second force.

6. An injection device according to claim 1, wherein the coupling mechanism comprises an engagement structure adapted to engage with the actuation member when the actuation member is subjected to the first force and further to reversibly disengage with the actuation member when the actuation member is subjected to the second force.

7. An injection device according to claim 1, wherein the actuation member comprises a longitudinal body and a contact surface for engagement with the engagement structure, the contact surface projecting laterally from the body surface.

8. An injection device according to claim 7, wherein the contact surface is at an obtuse angle to the body surface.

9. An injection device according to claim 8, wherein an angle between the contact surface and the body surface lies between 110 and 130 degrees.

10. An injection device according to claim 4, wherein the coupling mechanism comprises an engagement structure adapted to engage with the drive arrangement when the actuation member is subjected to the first force and further to reversibly disengage with the drive arrangement when the actuation member is subjected to the second force.

11. An injection device according to claim 5, wherein the bias means comprises a spring member adapted to store and release energy for translational and/or rotational motion.

12. An injection device according to claim 1, wherein the threshold value lies between 5N and 200N, preferably between 15N and 25N.

13. An injection device according to claim 5, wherein the threshold value is substantially equal to the biasing force of the bias means.

14. A system comprising:

an energizing part comprising an injection mechanism with an actuation member and bias means for biasing the actuation member in a first direction, and

a variable volume reservoir containing a liquid drug and comprising a movable wall,

wherein the actuation member and the movable wall are capable of mutual displacement in the first direction to reduce the volume of the reservoir and expel a dose of the liquid drug, and wherein the energizing part is configured to allow a reversible mutual displacement of the actuation member and the movable wall in a second direction in response to a force acting on the movable wall in the second direction.

15. A system according to claim 14, wherein the second direction is opposite to the first direction, and wherein the energizing part is configured to cause a mutual displacement of the actuation member and the movable wall in the first direction in response to a discontinuation of the force.