Patent ID: 8496621

Claim:
An injection device for injecting a pharmaceutical, the injection device comprising: a) an injection device body; b) a motor within the device body; c) a cartridge compartment within the injection device body, the cartridge compartment configured to receive a cartridge containing the pharmaceutical, the cartridge comprising a cylinder having an interior treated surface to reduce sliding forces of a movable stopper sealing one end of the cylinder and a cannula puncturable sealing disk sealing a second end of the cylinder, where the moveable stopper is configured to be slidably displaced axially towards the sealing disk within the cylinder to bring about a change in volume of the cylinder during injection; d) an exchangeable pump head of a peristaltic pump which is driven by the motor and by means of which the pharmaceutical is conveyed out of the cartridge; and e) control electronics comprising an adjusting mechanism, the adjusting mechanism allows presetting an amount of the pharmaceutical to be injected, the control electronics contained within the injection device body; wherein the exchangeable pump head is configured to be detachable from and reconnectable to both the motor and the cartridge and comprises detachable and functionally reconnectable interfaces to directly connect the exchangeable pump head to the motor and detachable and functionally reconnectable interfaces to directly connect the exchangeable pump head to the cartridge.