The GlucoWatch (R) biographer: a frequent, automatic and noninvasive glucose monitor

The GlucoWatch(R) (Cygnus, Inc, Redwood City, CA, USA) biographer provides automatic, frequent and noninvasive blood glucose measurements for up to 12 h. The device extracts glucose through intact skin where it is measured by an amperometric biosensor. Clinical trials in a variety of environments ha ve shown that the biographer provides accurate and precise glucose measurem ents when compared with serial fingerstick blood glucose measurements. Mean difference between these measurements was 0.26 mmol/L in the home environm ent (r = 0.80). Over 94% of biographer readings were in the clinically acce ptable A+B region of the Clarke Error Grid. A slight positive bias is obser ved for the biographer readings at low glucose levels. Biographer precision , as measured by coefficient of variation (CV)%, is approximately 10%. The low glucose alert function of the biographer was able to detect up to 75% o f hypoglycaemic episodes with a low false alert level. Skin irritation, cha racterized by erythema and oedema was either nonexistent or mild in over 87 % of subjects and resolved in virtually all subjects without treatment in s everal days. The GlucoWatch(R) biographer has been shown to be a safe and e ffective method to track glucose level trends and patterns, which should en able improved glycaemic control for many patients.