Abstract

We designed and constructed a new miniature, open-loop insulin infusion pump specifically to overcome the problems of many first generation insulin infusers. Special features are small size, adjustable volumetric basal infusion rate, rapid electronically mediated prandial insulin boosts, facility for doubling and halving the basal infusion rate and/or prandial delivery, and alarms for low battery state, motor over-run, stoppage, and control circuit malfunction. The infuser takes a specially designed syringe prefilled with short-acting insulin, sufficient in most diabetic patients for at least 7 days treatment with 100 U/ml insulin. To test clinical efficacy nine insulin-dependent diabetic patients received continuous subcutaneous insulin infusion (CSII) with the new infuser for periods up to 6 mo. Four patients previously CSII-treated with a first-generation pump and five who were new to CSII achieved and maintained the expected degree of near-normoglycemia. There were no pump breakdowns and a questionnaire completed by patients during the study confirmed ease and simplicity of operation and an appreciation of the advantages of the new pump compared with one widely used first-generation infuser.