Noninvasive glucose detection in human skin using wavelength modulated differential laser photothermal radiometry

Noninvasive glucose monitoring will greatly improve diabetes management. We applied Wavelength-Modulated Differential Laser Photothermal Radiometry (WM-DPTR) to noninvasive glucose measurements in human skin in vitro in the mid-infrared range. Glucose measurements in human blood serum diffused into a human skin sample (1 mm thickness from abdomen) in the physiological range (21-400 mg/dl) demonstrated high sensitivity and accuracy to meet wide clinical detection requirements. It was found that the glucose sensitivity could be tuned by adjusting the intensity ratio and phase difference of the two laser beams in the WM-DPTR system. The measurement results demonstrated the feasibility of the development of WM-DPTR into a clinically viable noninvasive glucose biosensor.