The artificial pancreas

Type 1 diabetes is an autoimmune disease in which the insulin-producing beta cells in the pancreas are destroyed by the body’s immune system. Insulin is a growth hormone that enables cells to take up glucose, which can be used immediately for energy or stored for future use. When insulin production is low or absent, as in patients with type 1 diabetes, glucose accumulates in the blood and is partially filtered out by the 148kidneys, leading to excessive urination and thirst. Instead of metabolizing glucose, the body metabolizes fats and creates byproducts called ketones. The buildup of these ketones can lead to a toxic condition called diabetic ketoacidosis, marked by nausea, weakness, confusion, and high levels of glucose and ketones in the blood and urine. Diabetic ketoacidosis can quickly lead to coma and death if it is not treated with exogenous insulin. Thus, until insulin was discovered in the early 20th century, the diagnosis of type 1 diabetes was usually a sentence of death within months. The most frequent complications of type 1 diabetes are those involving long-term exposure to high glucose levels (hyperglycemia)-for example, kidney failure, blindness, neuropathy, impotence, heart disease, stroke-or acute exposure to low glucose levels brought on by insulin overdose (hypoglycemia)-for example, seizure, coma.