Insulin pumps are portable devices attached to the body that continuously deliver amounts of rapid or short acting insulin via a catheter placed under the skin.
They are seen as a better alternative to insulin injections as they reduce the need for multiple insulin jabs per day and give the user increased ability to control blood glucose levels.
Around 1 in 1,000 people with diabetes wears an insulin pump.
What is an insulin pump?
An insulin pump is a small device (a little larger than a pack of cards) that delivers insulin into the layer of fat that sits just below the skin (subcutaneous tissue).
Because the insulin pump stays connected to the body, it allows the wearer to modify the amount of insulin they take within the press of a few buttons at any time of the day or to program in a higher or lower rate of insulin delivery to occur at a chosen time, which can be when sleeping.
An insulin pump consists of the main pump unit which holds an insulin reservoir which typically holds between 176 and 300 units of insulin.
The reservoir is attached to a long, thin piece of tubing with a needle or cannula at one end.
The tubing and the bit at the end are called the infusion set Insulin pump therapy is also referred to as continuous subcutaneous insulin infusion therapy
How common are pumps?
The UK Insulin pump audit of 2013 showed that:
- Around 6% of adults with type 1 diabetes use an insulin pump.
- Around 19% of children with type 1 diabetes use an insulin pump pump.
- Insulin pump therapy is offered to people with type 2 diabetes on a case-by-case basis, when a diabetes consultant with expertise in pump therapy believes strongly that it is the only appropriate treatment for a specific patient. Current research suggests that there is a small proportion of people with type 2 diabetes that have a clinical need for an insulin pump.
Currently, 10 insulin pumps are available in the UK. Read more about eligibility for getting a pump on the NHS
How does an insulin pump work?
Most insulin pumps (tethered insulin pumps) work by sending insulin, stored in a reservoir within the pump, into your body via an infusion set – a thin plastic tube attached to either a steel needle or a plastic cannula (a very narrow plastic tube). The needle or cannula is inserted into the subcutaneous tissue (the layer of fat tissue just beneath the skin), enabling the insulin to be absorbed gradually into the bloodstream.
Another common type of insulin pump is a patch pump which largely works in the same way except that patch pumps attach directly to the skin and therefore do not require a line of plastic tubing to help deliver the insulin to the cannula.
The dose of insulin that is delivered through the day and night can be varied depending on the rate that is pre-set according to your needs (i.e. diet, exercise and blood glucose levels).
Insulin pumps with integrated CGMs
The most modern trend in insulin pump technology is for pumps to directly interact with CGMs. Pumps that allow CGM integration include:
- Medtronic MiniMed 640G
- Medtronic MiniMed Paradigm Veo
- Animas Vibe with Dexcom G4 sensors
The MiniMed 640G and Paradigm Veo have an advanced feature that switches off insulin delivery if blood sugar levels become too low. The feature can shorten hypos and prevent severe hypos occurring.
NICE have endorsed the use of Paradigm Veo pump with CGM sensors for people on insulin therapy that are having problems with regular or unexpected hypos despite having otherwise strong blood glucose control.
Insulin pump history
Insulin pumps are a relatively new piece of diabetes desig, invented in the 1970s, although the first insulin pump prototype was developed in 1963.
- 1963: The first prototype of a ‘pump’ that delivered glucagon as well as insulin was similar to a backpack and was developed by Dr Arnold Kadish.
- 1973: Dean Kamen invented the first wearable infusion pump.
- 1976: AutoSyringe Inc begin to manufacture and market the pumps Dean Kamen invented.
- 1976: Development of continuous subcutaneous insulin infusion begins (insulin pump therapy).
- 1980s: BioStar glucose controlled insulin infusion system used- functioned as an artificial pancreas.
- 1990s: First Medtronic MiniMmed pump released.
- 2012: Trials of artificial pancreas’ begin in the USA.
Currently, companies such as Animas, Ypsomed and Medtronic lead the way in insulin pump technology, which has become smaller over the last 50 years.
How is an insulin pump worn?
Insulin pumps are connected to the body via the infusion set. The small needle or plastic cannula sits under your skin through the day whilst the infusion set is held in place by an adhesive that is similar to the sticky backing of a plaster.
The infusion set can usually be placed in the same sites on the body as are used for injections. The infusion set can usually be left in for two to three days. After this you must insert a new infusion set into a different place on your body. It is important to rotate sites, just as you should do with standard insulin injections.
The pump itself can be safely and discretely attached in lots of different ways, such as to a belt or the waist of trousers, held in pockets or in pouches attached to your thigh or upper arm.
Types of insulin used
Insulin pumps generally use rapid acting insulin, which acts very quickly to minimise the rise in blood sugar after eating. The pump, because it can continually deliver insulin through the day, can therefore use the same rapid insulin to provide a basal (background) dose of insulin.
What is insulin pump therapy?
Insulin pump therapy is the term used to describe the use of insulin pumps in managing blood glucose levels in people with insulin-dependent diabetes.
It is also known as continuous subcutaneous insulin infusion (CSII), which basically explains the function of an insulin pump; to continually infuse insulin into the layer of fat just under the skin (subcutaneous tissue).
Insulin pump therapy has been recognised as being effective in helping people with diabetes, particularly people with type 1 diabetes, to achieve improved HbA1c levels and, in many cases, helping to improve quality of life.
Are insulin pumps better for people with diabetes?
Supporters of insulin pumps believe that they allow diabetics to be more flexible, and eliminate the need for a wearing, daily routine.
A diabetic with an insulin pump does not necessarily have to rise at a certain time to take insulin. When it comes to diet, insulin pumps allows you to be more flexible with that they eat, if they are used in the correct way.