Dual-Frequency Microwave Resonant Sensor to Detect Noninvasive Glucose-Level Changes Through the Fingertip

Abstract

In this article, which is a fundamental step in an underway research, a microwave resonant sensor at two resonance frequencies of 5.5 and 8.5 GHz (in order to increase the accuracy of the application) with a quality factor of 180 and 106, for blood glucose level monitoring is designed, fabricated, and tested by users' fingertips. In this study, 11 volunteers were tested invasively (using a glucometer) and noninvasively (using the proposed glucose resonant sensor) with range of glucose-level changes from 89 to 262 mg/dL. For this range of glucose-level changes, the frequency detection resolution is 3.53 and 3.58 MHz/ (mg/dL), respectively. The results of the experiments are relatively well matched; so that compared to the glucometer device, the proposed sensor shows a maximum measurement error of about 3% to detect glucose levels.