Insulin pump, also known as continuous subcutaneous insulin infusion (CSII) device, is a program-controlled pump device that can continuously inject microinsulin. It can mimic the physiological secretion pattern of human insulin to replenish patients with the right amount of insulin, and is suitable for patients with type 1 diabetes and advanced type 2 diabetes who require insulin injections for a long period of time, as well as for the stage of gestational diabetes when blood sugar fluctuates dramatically. This technique has been used for decades and is known as an open-loop insulin pump, which requires an experienced diabetologist to help the patient to set the daily basal and pre-meal amounts of insulin and to adjust them according to different conditions.
The current closed-loop insulin pump is more like a machine with a computer, which consists of a blood glucose sensor (to monitor blood glucose changes at any time and anywhere), a feedback adjustment system (which is the central controller) and an insulin infuser. Therefore, it is also called “artificial insulin”. But now it is further developed into a closed-loop system of two hormones, one is the original insulin responsible for lowering blood sugar, and the other is glucagon responsible for raising blood sugar, both of which work together to keep blood sugar dynamically stable, neither high nor low. It is especially suitable for diabetic patients with frequent hypoglycemia, including type 1 diabetes, patients with autonomic neuropathy with impaired blood glucose sensation, and patients with impaired glucagon secretion as well.
Generally when the patient’s blood sugar is greater than 6.5mmol/L, the insulin pump will automatically infuse insulin; and when the blood sugar is lower than 6.5mmol/L, the infusion of glucagon will be started; if the blood sugar continues to fall below 4.5mmol/L, the system will increase the infusion dose of glucagon; once it is lower than 3.5mmol/L, this closed-loop blood sugar will alarm to prompt the patient to eat in time .
Since the level of blood glucose in the body is regulated by multiple hormone levels, in addition to the current insulin and glucagon, a closed-loop system of multiple hormone infusions may be developed in the future, including the infusion of enteroglucagon GLP-1 (glucagon-like peptide-1).