Feedback control is an important mechanism for reaching a targeted goal.Biologic examples range from achieving the appropriate blood pressure level to glycemia control. Computer-based feedback control systems have many potential applications in medicine. Closed-loop systems directly sense the state of the patient and then deliver an intervention without human action. Closed-loop systems have been used to control postoperative fluid infusion, reduce malignant hypertension to a reasonable range through nitroprusside infusions, and control continuous insulin infusions—in effect, an artificial pancreas. Sensory problems have limited the direct application of closed-loop systems to date; most current medical uses of computer-based feedback control are open loop, where a human is interposed between the suggested intervention and the delivered treatment.
Because many variables important to the management of diabetes are objective, many opportunities exist for open-loop control in diabetes management. Open-loop systems have already been used to suggest insulin dosage adjustments and treatments for hypercholesterolemia and to remind physicians of various interventions to reduce the complications of diabetes mellitus. However, existing applications have only scratched the surface. Many more facets of diabetes management could be standardized and assisted by open-loop control systems if the management rules could be more exactly specified, a task requiring substantial time commitments by diabetologists. Efforts to translate existing knowledge bases into precise guidelines will be helpful, but new primary studies and decision analyses are needed to define the optimal use of some interventions.