About three million Americans have Type 1 Diabetes, which occurs when the patient's immune system attacks the beta cells that produce insulin in the pancreas. Individuals with the disease typically have to receive insulin injections or infusions. A collaboration between researchers at Massachusetts General Hospital and Boston University has resulted in the development of a bionic pancreas that outperformed an insulin pump. The device was described in detail in the New England Journal of Medicine.

The device involves a sensor which is implanted under the skin that relays information to an iPhone app. Every five minutes, it sends information about blood sugar levels in the body, and facilitates insulin dispersal from a pump when needed. 

The user doesn’t have to determine how many carbs were eaten in a meal in order to input the information into the pump. According to the paper, a small amount of information is needed from the user, and the device handles the rest: “The user interface displayed the continuous-glucose-monitor tracing and insulin and glucagon doses, and allowed announcement of meal size as “typical,” “more than usual,” “less than typical,” or “a small bite” and the meal type as “breakfast,” “lunch,” or “dinner.” This triggered a partial meal-priming bolus, which automatically adapted insulin dosing to meet 75% of the 4-hour postprandial insulin need for that meal size and type.”

The study was fairly small, using only 20 adults and 32 children for a span of 5 days each. The adults stayed in a hotel for five days for monitoring and were given dietary freedom, though they were told to limit alcohol consumption. The children were at a facility sort of like a summer camp, and were also not restricted in what they could eat. To be sure the devices were functioning properly, their blood sugar was periodically tested via finger pricks.

At the end of the five day period, the study participants had overall healthier blood sugar levels using the bionic device than with using traditional management options. Typically, diabetics monitor their blood sugar several times per day and calculate how much insulin they need. The insulin can either be administered with a pump, or measured and injected. If insulin is not given properly, sugar can build up in the body, putting the patient at an increased risk for seizure, stroke, or heart disease.

In addition to just dispersing insulin, which lowers blood sugar, the device is also able to deliver glucagon, which increases it. This helps keeps blood sugar levels even, rather than experiencing large fluctuations.

A great deal of further study will be needed before this device can be approved by the FDA, though researchers hope the device will be ready within the next three years. The next phase of study will involve 40 adults who will use the implanted device for 11 days.