Description:
<jats:p> A major new approach to the improvements of metabolic control in insulin-dependent diabetic patients is the replacement of insulin by delivery systems which simulate non-diabetic insulin secretory patterns. In the last ten years a number of open-loop, extracorporeal, portable infusion pumps have been used in research trials tasting from a few days to several years. Routine treatment by insulin pumps is now being considered. Most infusers are syringe-drivers, although peristaltic and reciprocating pumps have also been employed. All are based on a slow, basal delivery rate, supplemented by insulin boosts at meal-times. The most popular infusion route is via the subcutaneous tissue. Technological development is concentrating on miniaturisation, alarms (such as low battery state and motor over-run) and more flexible/programmable delivery rates. </jats:p><jats:p> Attempts are in progress to ‘close the loop’ using an implanted glucose sensor. Most electrodes are amperometric or potentiometric enzyme sensors employing immobilised glucose oxidase. Encouraging in vivo results are being obtained from a novel amperometric biosensor which uses ferrocene to mediate electron transfer. The most likely implantation site is the subcutaneous tissue. </jats:p>