EP0293958B1 — Injection pen

USPTO Abstract

Injection pen (1) suitable for being carried in the clothes of a user-patient, comprising a housing (26) incorporating an injection fluid reservoir (3) or cartridge having a variable content, a pump rod (4) that can be biassed against said reservoir (3) or cartridge for altering the content thereof and a drive mechanism for moving said pump rod (4), wherein said drive mechanism comprises an electromotor (6) which is controlled by an electronic control unit (7) comprising i.a. memory means (11), for storing data such as data corresponding to the reservoir stock status (12) and to a number of units of injection (15) fluid to be delivered to the user-patient, and comparator means (20) for comparing said number of units of injection fluid with the reservoir stock status (19) and for controlling the electromotor. Preferably the control unit comprises an integrated circuit incorporating a processor.