There are four components to an insulin pump: the pump itself, a reservoir, tubing, and an infusion set.
An insulin pump is a small, battery-powered computer that is about the size of a pager. It is worn clipped to a belt or waistband, or in a pouch or pocket. The pump holds a reservoir filled with rapid-acting insulin. The pump is programmed to give small continuous amounts of insulin from the reservoir through a small plastic tube connected to your body. At the end of the tubing is a small needle, which is used to insert the cannula (a small hollow tube) into the fatty tissue of the stomach or other area. The needle is then removed leaving the cannula behind, which is called the infusion set. Some pumps do not have a tube and the insulin is housed in a device worn on the body. The reservoir and infusion set are changed every 2-3 days. The pump can be disconnected from the infusion set for short periods for activities such as swimming, bathing, or exercise.
The insulin pump is not an “artificial pancreas” and is not automatic. You must program it to give insulin when you need it. Therapies such as multiple daily injections (MDI) and insulin pump therapy, formally known as continuous subcutaneous insulin infusion (CSII), keep blood sugars in a tighter range. Blood sugars must be monitored at least 4-7 times every day for pump therapy to be safe and effective. An insulin pump does not monitor your blood sugar levels.