An implantable continuous glucose monitoring microsystem in 0.18µm CMOS

We present a fully implantable subcutaneous continuous glucose monitoring (CGM) microsystem on CMOS platform. The proposed design incorporates electrochemical sensing technique using an ultra-low-power potentiostatic system. It is wirelessly powered through an inductive coupling link at 900MHz and supports bidirectional data communication with an external reader. A low-power potentiostat and a dual-slope ADC record the on-chip sensor signal. Pt and Ag/AgCl on-chip electrodes are post-fabricated and functionalized in situ by glucose oxidase enzyme to enable glucose measurement. The 1.4×1.4×0.25mm3 prototype fabricated in a 0.18μm CMOS technology was validated in glucose measurements. Total power consumption of the system is 6μW.