Claims for Patent: RE41956

Summary for Patent: RE41956

Title:	Dose setting limiter
Abstract:	A limiting mechanism which prevents the setting of a dose, which exceeds the amount of liquid left in a cartridge of an injection device, is disclosed. The injection device is the type where a dose is set by rotating a dose setting member relative to a driver and away from a fixed stop in the injection device. The dose setting member interfaces the driver such that the dose setting member can be rotated in one direction without rotating the driver. The dose is injected by rotating back the dose setting member which during the backward rotation carries the driver with it. Rotating the driver causes the piston rod to move forward inside the cartridge and expel some of the liquid contained in the cartridge. The driver is provided with a track having a length which is related to the total amount of liquid in the cartridge and which track is engaged by a track follower coupled to the dose setting member to follow rotation of this dose setting member. Each time a dose is set and injected, the track follower moves further into the track. When the track follower reaches the end of the track the dose setting member can not be rotated further, and a dose larger than the remaining liquid in the cartridge cannot be set.
Inventor(s):	Klitgaard; Peter Christian (Glostrup, DK), Hansen; Steffen (Hillerod, DK), Radmer; Bo (Hillerod, DK), Moller; Claus Schmidt (Fredensborg, DK)
Assignee:	Novo Nordisk A/S (Bagsvaerd, DK)
Application Number:	11/122,211
Patent Litigation and PTAB cases:	See patent lawsuits and PTAB cases for patent RE41956
Patent Claims:	1. A limiting mechanism that prevents setting of a dose that exceeds the .Iadd.injectable .Iaddend.amount of liquid left in a cartridge of an injection device wherein a dose is set by rotating a dose setting member relative to a driver and away from a fixed stop in the injection device, and the dose is injected by .[.rotating.]. .Iadd.pressing an injection button which rotates .Iaddend.back the dose setting member which during this rotation carries the driver with it to rotate this driver which moves the piston rod forward, wherein the driver is provided with a track having a length which is related to the total .Iadd.injectable .Iaddend.amount of medicament in the cartridge and which track is engaged by a track follower coupled to the dose setting member to follow rotation of this dose setting member and wherein the driver is disk shaped and the track has a spiral shape which is engaged by the track follower which is flexibly coupled to the dose setting member so that the track follower can be moved radially when it follows the track of the driver element. 2. A limiting mechanism that prevents setting of a dose that exceeds the amount of liquid left in a cartridge of an injection device wherein a dose is set by rotating a dose setting member relative to a driver and away from a fixed stop in the injection device, and the dose is injected by rotating back the dose setting member which during this rotation carries the driver with it to rotate this driver which moves the piston rod forward, wherein the driver is provided with a track having a length which is related to the total amount of medicament in the cartridge and which track is engaged by a track follower coupled to the dose setting member to follow rotation of this dose setting member and wherein the driver is cylindrical and the track has a helical shape which is engaged by the track follower which is coupled to the dose setting member so that the track follower can be moved rotationally when it follows the track of the driver element. 3. The limiting mechanism of claim 2, wherein the dose setting element is a cylinder concentric with the driver. 4. The limiting mechanism of claim 3, wherein the track comprises a thread in the driver and that the track follower comprises a nut shaped member coupled to the dose setting member and provided with a thread engaging the thread of the driver. .Iadd.5. A dose setting limiter assembly that prevents the setting of a dose which exceeds the remaining injectable amount of medication in a multiple dose cartridge in an injection device which comprises: a cylindrical dose setting member having an outer wall provided with a helical groove which allows the cylindrical dose setting member to be screwed out of the injection device and away from an initial position when the cylindrical dose setting member is rotated during dose setting and screwed into the device and toward the initial position to reduce the size of a set dose, wherein during injection of the set dose the cylindrical dose setting member is pressed back into the device and as a result of the helical groove it rotates back toward the initial position; wherein the dose setting limiter assembly comprises: (a) a helical track disposed on the outer surface of a hollow cylindrical driver that drives a separate piston rod forward; and (b) a follower that engages the helical track; wherein the follower moves along the helical track when the dose setting member is rotated during dose setting; but wherein the follower does not move along the track during injection of the set dose; wherein the injection of the set dose is carried out by pressing an injection button which: (i) presses the cylindrical dose setting member back into the device, and (ii) causes the cylindrical dose setting member to rotate back to the initial position, wherein the rotation back is cause by the helical groove on the dose setting member; wherein the position of the follower along the track is indicative of the total sum of the set and injected doses; wherein the length of the helical track that the follower can move along corresponds to the amount of medication in the cartridge that is available to be injected; and wherein the follower abuts a stop at the end of the track during dose setting before the cylindrical dose setting element can be rotated to dial up a dose that would exceed the injectable amount of medication remaining in the cartridge..Iaddend. .Iadd.6. The dose setting limiter assembly of claim 5, wherein when the follower abuts the stop at the end of the track during dialing up of a dose, the cylindrical dose setting member cannot be rotated further to increase the size of the dose..Iaddend. .Iadd.7. The dose limiter assembly of claim 6, wherein the follower is a nut like element and the helical track is a thread and wherein the follower engages the thread..Iaddend. .Iadd.8. The dose limiter assembly of claim 7, wherein the driver, the helical grove, the helical track, and the dose setting member are oriented so that they are all coaxial..Iaddend. .Iadd.9. A dose limiter mechanism for use with in an injection device, which comprises: (i) a rotatable hollow cylindrical dose setting member containing a threaded groove on its outer surface so that it screws out of the injection device during setting of a dose when it is rotated, screws back into the housing to reduce the size of a set dose when it is rotated back, and screws back into the housing when an injection button is pressed during injection, and (ii) a hollow cylindrical piston rod driver that is coaxial with the hollow cylindrical dose setting member; wherein the dose limiting mechanism operates within the injection device to prevent the setting of a dose that exceeds the injectable amount of medication remaining in a multiple dose cartridge in the device; and wherein the dose limiter mechanism comprises: a helical track disposed on the outer surface of the piston rod driver, the helical track having a length that corresponds to the injectable amount of medication in the cartridge; a follower that engages the helical track and moves along the helical track when the dose setting member is rotated during dose setting but that remains in a fixed position on the helical track when the dose setting member is rotated back when the injection button is pressed during injecting of medication, and wherein the distance the follower moves during dose setting corresponds to the size of the set dose and wherein the follower abuts a stop at the end of the helical track when an attempt is made to rotate the dose setting member during dose setting that would result in a dose being set that exceeds the remaining injectable amount of medication in the cartridge..Iaddend. .Iadd.10. The mechanism of claim 9, wherein the hollow cylindrical dose setting member is prevented from rotating to increase the size of a set dose when the follower hits the stop..Iaddend. .Iadd.11. The mechanism of claim 9, wherein the track on the hollow cylindrical piston rod driver forms a thread and follower comprises a nut like element that threadly engages the thread..Iaddend. .Iadd.12. The mechanism of claim 10, wherein the track on the hollow cylindrical piston rod driver forms a thread and the follower comprises a nut like element that threadly engages the thread..Iaddend. .Iadd.13. An injection device dose limiter assembly for use with both (a) a rotatable cylindrical dose setting member, which threadly engages an injection device housing element so that (i) when it is rotated to set the size of a dose it screws out of an injection device housing, (ii) when it is rotated back to reduce the size of a set dose it screws back into the housing, and (iii) when an injection button is pressed during injecting of medication the cylindrical dose setting member is pressed back into the housing and rotates back, and (b) a hollow cylindrical piston rod driver that drives a separate piston rod during injection of the set dose; wherein the injection device dose limiter prevents the setting of a dose that is larger than the injectable amount of medication remaining in a multi dose cartridge and wherein the injection device dose limiter assembly comprises: a helical track disposed on the outside of the hollow cylindrical piston rod driver; and a follower that moves along the track during dose setting but remains stationary with respect to the helical track during dose injecting when an injection button is pressed which causes the cylindrical dose setting member to be screwed back into the housing; wherein the length of the track that the follower is capable of moving along corresponds to the injectable amount of medication in an injection device multiple dose cartridge; and wherein during dose setting: the follower moves a distance along the track that corresponds to the size of the dose being set; and wherein the follower abuts a stop before the size of the set dose exceeds the injectable amount of medication remaining in the cartridge..Iaddend. .Iadd.14. The assembly of claims 5 or 13, wherein the follower abuts the stop when the size of the set dose equals the injectable amount of medication remaining in the cartridge..Iaddend. .Iadd.15. The assembly of claims 5 or 13, wherein the helical track has a length adapted to ensure that the follower stops advancing when the size of a set dose is equal to that remaining for injection..Iaddend. .Iadd.16. The assembly of claims 1, 5, or 13, wherein the injection button moves a distance proportional to, but a number of times greater than, the distance a piston in the cartridge moves during delivery of the set dose during dose injecting..Iaddend. .Iadd.17. The mechanism of claim 9, wherein the follower abuts the stop when the size of the set dose equals the injectable amount of medication remaining in the cartridge..Iaddend. .Iadd.18. The mechanism of claim 9, wherein the helical track has a length adapted to ensure that the follower stops advancing when the size of a set dose is equal to that remaining for injection..Iaddend. .Iadd.19. The mechanism of claim 9, wherein the injection button moves a distance proportional to, but a number of times greater than, the distance a piston in the cartridge moves during delivery of the set dose during dose injecting..Iaddend.