The GlySens continuous glucose sensor is uniquely designed to function effectively as a long term implant in subcutaneous tissues. The sensing principle is based on the utilization of two sensors that are both incorporated in the implantable device: (1) a glucose sensor in which a selective chemical reaction, involving glucose and oxygen, is monitored by an electrochemical oxygen detector; and (2) an oxygen reference sensor to detect tissue oxygen. The sensor's electronic circuitry automatically determines the difference between the signals from these two sensors and utilizes the difference to determine glucose levels. This approach helps ensure the specificity of the glucose measurement by eliminating the effects of secondary factors such as temperature, blood flow in the surrounding tissues, and long term changes due to the body's normal mild encapsulation response to the implant. Utilization of the oxygen reference sensor thus enables a "difference measurement" of glucose that is robust and remarkably free from many common artifacts.

Another key feature of the GlySens technology is a unique method for prolonging the working lifetime of the sensor's immobilized enzyme element, which catalyzes the chemical reaction between glucose and oxygen. With the unique differential oxygen detection method, a second immobilized enzyme can be included that preserves the primary enzyme and simultaneously minimizes unwanted tissue response to the implant. These and other design features, unique to the GlySens approach, make possible a uniquely long life for the GlySens glucose sensor.