Insulin Delivery Devices

Today, the efficiency of the insulin delivery system of the insulin pump is closest to the natural human pancreas.

This device is quite similar to a pager and is fixed to the waist belt of the patient. A small canula or a needle is inserted into the subcutaneous tissue through which insulin is continuously delivered. This canula is attached to an insulin cartridge. The dosage is predetermined. The site of injection is to be changed every three days. The insulin is infused from the pump reservoir through an infusion set.

At any given time certain insulin is delivered to the body as a “basal” dose. This dose can be varied at different times. The patient has to deliver an extra dose (bolus) during or after meals. The insulin dose starts at 0.1 units. The patient can decide the rate at which this bolus is to be delivered.

The pump can be programmed to deliver the insulin either in its regular mode (plain bolus) or to deliver the insulin over a period of time (square bolus), E.g. in case a meal has lot of fat, a square bolus can be programmed. In case of a meal having a combination of fat food as well as quick acting carbohydrate, a combination of plain and square bolus can be programmed.

This method is more suitable for type I diabetics. However the people using the pump must monitor the blood glucose 3-4 times a day to make sure that the pump is working well.

Adequate knowledge regarding calorie counting is very important to decide the bolus that needs to be delivered after each meal.

Advantages:

• Patients have greater flexibility in choosing food as all they need to do is to count the carbohydrates value and set the bolus which will enable them to have normal blood glucose levels.
• Pricking the body 2-3 times a day is avoided.

Disadvantages:

• It is expensive, and therefore unaffordable by the common man.
• Knowledge regarding carbohydrate counting needs to be mastered to decide the bolus dose.
• The device needs to be worn all the time.
• Monitoring the blood glucose several times a day is required to ensure that the insulin delivery by the pump is not interrupted.