One of the fondest hopes of people with type 1 diabetes has long been for the creation of an artificial pancreas, a reliable combination of automated glucose monitoring and insulin delivery that could serve in place of a defunct pancreas.
Apparently the hoped-for day may be here: Researchers from the University of California and Sansum Diabetes Research Institute, in Santa Barbara, California, have demonstrated an automated artificial pancreas system that they say is reliable enough to free type 1 patients from having to manually control their insulin pumps.
The scientists introduced the system, which combines the OmniPod insulin delivery system and the DexCom STS7 continuous glucose monitor with a software component, to the 69th Scientific Sessions of the American Diabetes Association in New Orleans earlier this month. (OmniPod is manufactured by Insulet Corporation; DexCom is manufactured by DexCom, Inc.)
Creation of an artificial pancreas has not lacked for available components. Such a system would combine a way of measuring blood glucose levels-a continuous glucose monitor-with a way of delivering an appropriate amount of insulin to correct glucose levels-an insulin delivery pump. But the problem has been the interface between the two.
Until now, there has been no reliable way to bypass the need for patients to consciously respond to promptings from their monitors and decide how much corrective insulin they should tell their pumps to inject. If patients give themselves an improperly high dose, they run the risk of hypoglycemia; if they inject too little, they risk hyperglycemia. Even more problematic is the possibility that patients might forget to read their monitors-also an invitation to glycemic imbalances.
The Santa Barbara scientists believe that they have gotten around the problem by developing an insulin delivery algorithm, tailored to each individual user, that “tells” the pump when and how much insulin to deliver in response to the monitor’s reading of too-low or too-high blood glucose levels.
In experiments with induced high levels of BG, the software-driven monitor/pump combination was able to restore normal BG levels by automatically delivering insulin at an infusion rate designed to ensure a smooth return to normal and avoid hypoglycemia.
For some time now, type 1s who use monitors and pumps have been able to fine-tune their BG levels, thus managing their disease and adding to their longevity. The prospect of being able to rely on their devices to do so automatically is a dramatic next step. Even so, researchers and manufacturers are mindful of the vulnerabilities of complex computerized and miniaturized components in both systems. In addition to great software that coordinates monitors and pumps, the devices themselves need to be sturdy, reliable, and foolproof.