AN INFUSION PUMP SYSTEM, AN INFUSION PUMP UNIT AND AN INFUSION PUMP

摘要

An infusion pump unit, comprising a housing of a size allowing the pump unit to be carried by a user as a portable infusion pump unit, a fluid inlet 50 for establishing fluid communication from an external infusion bag to said fluid inlet, a fluid outlet 52 for establishing fluid communication to an infusion site, a controllable pumping system 90 for pumping fluid from the fluid inlet 50 to the fluid outlet 52 and a shape memory alloy actuator 78 for operating the pumping unit, the actuator 78 comprising a pivotable body 1' having a yoke 5' for displacing an actuator means 15' linearly when the body 1' pivots under the influence of two shape memory alloy wires 9' and 10a' and a tension spring 6' such that alternative heating and cooling of the shape memory wires 9' and 10a' reinforced by the action of the spring 6' pivots the body 1' to and fro.