What is an Insulin Pump? How Does it Work?

Intro to Insulin Pumps

An insulin pump is a medical device, about the size of a cell phone, which infuses insulin through a small cannula (made of metal or flexible “plastic”) inserted into the layer of fat under the skin and held in place by an adhesive pad.

As one choice among different insulin program options, a pump program, also referred to as Continuous Subcutaneous Insulin Infusion (CSII), is an alternative to multiple daily injections via syringes/insulin pens (although injections are still occasionally required when there is a temporary problem with insulin delivery through the pump).

Typical sites for infusion include: the tummy/abdomen, the buttocks, thighs, and upper arm. In some models of insulin pump, the cannula is then connected to a length of plastic tubing, which transports insulin from the pump cartridge/reservoir to the infusion set; another “tubing-free” model eliminates the tubing by housing the cartridge/reservoir in a “pod” with a built-in cannula, which adheres to the skin. Either form of infusion set is replaced every 2-3 days.

Waltzing The Dragon Inc

An insulin pump replaces long-acting or intermediate-acting basal insulin with tiny amounts of rapid-acting insulin delivered automatically every few minutes, PLUS, when a user pushes the appropriate buttons, the pump delivers a bolus of rapid-acting insulin to cover each meal and snack.

Today’s pumps also calculate a recommended dose of insulin, based on the rates and ratios a user has previously programmed in. In addition, temporary basal rates can be set to increase or decrease the amount of basal insulin delivered for a specified period of time, and there are options for extended boluses to deal with high fat or low glycemic foods (such as pizza, and pasta, respectively).

  • The above information was reviewed for content accuracy by clinical staff of the Alberta Children’s Hospital Diabetes Clinic.