An intrathecal drug infusion system has been designed, manufactured and tested. The system is composed of a drug reservoir and a pump/controller assembly. The drug reservoir made of SUS316L is a negative pressure gas chamber enclosing a bellows type drug chamber. The pump/controller assembly includes a bacterial filter, a controller circuit board, a battery and a micropump, and is connected to a catheter for intrathecal infusion. The micropump implements a peristaltic pumping of the drug by a sequential motion of three pairs of cam and cam-follower. In vitro performance tests were conducted with prototypes.