Many people with diabetes dread the frequent testing necessary to monitor their glucose levels—testing that generally involves pricking their fingers to draw blood. A diabetes sensor offers an efficient and less-painful alternative to the traditional glucose meter. Formally known as a continuous glucose monitor (CGM), this sensor for diabetes is inserted under the skin, where it continuously checks the patient’s glucose levels for up to seven days. The monitor sends a signal every few minutes to a device similar to a pager. This device then displays the diabetic’s glucose levels and alerts the patient if dangerously high or low blood-sugar levels are reached.

These continuous glucose monitors have gained popularity as technology continues to improve. In the last few years, federal officials have approved the use of this type of diabetes sensor for children, and scientists are currently testing monitors that can remain implanted in a diabetic’s body for more …