Patient-controlled analgesia using a miniature electrochemically driven infusion pump.

We describe a miniature electrochemically driven, wrist-worn infusion pump. Generation of gas by an electrolytic reaction compresses a reservoir containing medication and provides a predictable and controllable infusion rate. The pump was used for patient-controlled analgesia (PCA) in women who required analgesia after Caesarean section. It was accepted readily and was convenient for both patients and nursing staff. This portable system, using a novel motive force, has advantages of convenience over larger systems and has sophisticated features not present in existing small systems. It has potential as a routine PCA device and it may have uses in other situations requiring convenient infusion or intermittent injection in an ambulatory setting.