| abstract |
A controllable drug delivery device for delivering a liquid injectable drug, the device comprising a drug reservoir ( 22 ), a drug administration device ( 28 ), a displacement-generating battery ( 20 ), and a current-depletion circuit ( 85 ), wherein displacement generated by the battery as current is depleted from the battery by the current depletion circuit displaces a wall of the drug reservoir thereby causing the reservoir to expel liquid injectable drug contained therein via the drug administration device, and wherein the drug delivery device further includes a controller ( 78 ) that is responsive to a measured parameter indicative of displacement generated by the battery for applying a variable load ( 80 ) across the battery in order to provide a substantially constant-current depletion of the battery and thereby cause the drug delivery device to deliver a substantially constant drug delivery rate. |