One of the toughest tasks an insulin dependent diabetic has is to accurately estimate the correct dosage of insulin for a given meal. The term used to describe this insulin dose is a Bolus. Ideally, the postprandial blood glucose value (after a meal) must not exceed 120 after about 2 hours. I have been tweaking my bolus insulin doses for lunch the last few days, and finally got it right today. Three hours after lunch, my blood glucose was a normal 80. The device in the photograph is the receiver from a Dexcom Seven Continuous Glucose Monitoring System (CGMS). The sensor consists of a thin wire inserted subcutaneously into my skin and a radio transmitter that transmits blood glucose values every five minutes to the receiver.