An extracorporeal medication infusion device provides a precise infusion rate of a liquid medication into a human or animal body. The infusion device includes a permanent portion which has a case, a battery, a programmable electronic controller, and an electromagnetic solenoid core and solenoid coil...http://www.google.fr/patents/US4447233?utm_source=gb-gplus-shareBrevet US4447233 - Medication infusion pump
