An artificial pancreas is a medical device that is used to better control blood sugars in individuals with diabetes. It is called an artificial pancreas because it mimics some of the functions of a healthy pancreas. It is also called a closed loop system, an automated insulin delivery system, or an autonomous system for glycemic control. In truth, it is several devices rolled into one.
Functions of the Pancreas
To understand what an artificial pancreas does and how it works it is helpful to first understand the functions of the pancreas in the body and the important hormones it produces and regulates.
The pancreas is located in the abdomen near the stomach and liver and has an elongated shape. It is often referred to as an organ but it may be more accurate to call it a gland; it functions to produce and release the vital hormones insulin and glucagon which play an important role in regulating blood sugar levels.
The pancreas is part of the endocrine system and the digestive system. In addition to producing insulin and glucagon the pancreas produces and releases digestive enzymes.
While insulin is released into the bloodstream, the digestive enzymes are released into the pancreatic duct. They eventually reach the small bowel where they help to break down the food we eat.
The islets of Langerhans are the cells within the pancreas that create and secrete insulin and glucagon, while Acinar cells within the pancreas create and secrete digestive enzymes.
Diabetes and the Pancreas
Diabetes occurs as the result of either the pancreas failing to produce enough insulin to regulate blood sugar or as the result of insulin resistance.
When the body fails to produce enough insulin it often occurs in children or younger people who are not overweight. It is thought to be caused by an autoimmune disease that results in the immune system attacking and destroying the specialized cells, the islets of Langerhans, in the pancreas that make insulin.
It is also possible that some people are simply not born with enough of these cells to keep up with insulin production. This type of diabetes is usually referred to as Type 1 diabetes.
Insulin resistance is when the body is making insulin but the cells do not respond to it or use it the way that should. This type of diabetes often occurs in older people who are often overweight and is called Type 2 diabetes.
The Artificial Pancreas Device System
The artificial pancreas is a device that mimics some (but not all) of the functions of the pancreas and is typically used to treat Type 1 diabetes. Type 1 diabetes is managed by frequently checking your blood sugar levels then administering insulin when the blood sugar level is too high or glucose when the levels are too low. The artificial pancreas consists of several devices which perform these functions automatically.
The artificial pancreas that was approved by the U.S. Food and Drug Administration (FDA) in 2016 is called the MiniMed 670G. It is not considered a “fully automatic” artificial pancreas because some input is still required by the person wearing the device. For example, you may have to input the amount of carbohydrates that you consume during a meal and still check your blood sugar to calibrate the device. Current research is underway to develop a fully automatic pancreas.
There are three types of devices contained within the artificial pancreas. They are a continuous glucose monitoring system, a computer-controlled algorithm device, and an insulin infusion device.
Continuous Glucose Monitoring System
This device continuously and automatically monitors your blood sugar and sends the information to the computer controlled algorithm device. The continuous glucose monitoring (CGM) system eliminates the need to prick your finger and manually test your blood sugar multiple times throughout the day. It is a sensor that is inserted just below your skin (subcutaneously). The MiniMed 670G checks your blood sugar every five minutes.
You may still have to periodically check your blood sugar in order to calibrate your CGM system, but for people who are checking their blood sugar many times throughout the day, the CGM can be life-changing.
It can also do a better job of detecting increasing or decreasing blood sugar levels and alert you before your blood sugar reaches a critical level.
Computer Controlled Algorithm Device
This can be a smartphone, home computer, or another type of computer but, regardless, functions to communicate between the continuous glucose monitoring system and the insulin infusion device. It performs complex mathematical equations and tells the insulin pump how much insulin you need based on the results.
Insulin Infusion Device
The insulin infusion device can deliver insulin subcutaneously and eliminates the need for multiple insulin shots throughout the day. Insulin pumps are also available separately (not as part of an artificial pancreas) but you usually have to manually input the dose.
The MiniMed 670G is capable of automatically decreasing your insulin dose if your CGM detects low blood sugar or increasing it when your blood sugar is high (it will do this in either mode). It has a manual mode which allows you to program the insulin pump to deliver a specific basal dose of insulin and an auto mode. In auto mode, the MiniMed 670G will adjust the basal rate of insulin according to the results coming from the CGM.
Who Can Get an Artificial Pancreas
Currently, the only artificial pancreas device approved by the FDA is the MiniMed 670G. In the future, other more advanced and “fully automated” devices may be approved and have different requirements for who can benefit from their use.
The MiniMed 670G is currently approved for people with Type 1 diabetes over the age of 14 who require more than eight units of insulin per day.
It should not be used in people under the age of 7 (the effectiveness of its use in people ages 7 to 14 is currently being studied).
You must have a prescription for an artificial pancreas and maintain close contact with your physician. You also need to be willing to check your blood sugar periodically to calibrate the CGM and carry a medical identification card with you.