In Vivo Noninvasive Monitoring of Glucose Concentration in Human Epidermis by Mid-Infrared Pulsed Photoacoustic Spectroscopy

Abstract

The noninvasive determination of glucose in the interstitial layer of the human skin by mid-infrared spectroscopy is reported. The sensitivity for this measurement was obtained by combining the high pulse energy from an external cavity quantum cascade laser (EC-QCL) tunable in the infrared glucose fingerprint region (1000-1220 cm(-1)) focused on the skin, with a detection of the absorbance process by photoacoustic spectroscopy in the ultrasound region performed by a gas cell coupled to the skin. This combination facilitates a quantitative measurement for concentrations of skin glucose in the range from <50 mg/dL to >300 mg/dL, which is the relevant range for the glucose monitoring in diabetes patients. Since the interstitial fluid glucose level is representative of the blood glucose level and follows it without significant delay (<10 min), this method could be applied to establish a noninvasive, painless glucose measurement procedure that is urgently awaited by diabetes patients. We report here the design of the photoacoustic experiments, the spectroscopy of glucose in vivo, and the calibration method for the quantitative determination of glucose in skin. Finally, a preliminary test with healthy volunteers and volunteers suffering from diabetes mellitus demonstrates the viability of a noninvasive glucose monitoring for patients based on the combination of infrared QCL and photoacoustic detection.

Sensing glucose based on its affinity for concanavalin A on a glassy carbon electrode modified with a C60 fullerene nanocomposite

“…To apply the method for saliva sample detection, saliva sample was collected from healthy subject in the morning and the method measure the salivary glucose level (SGL) of 0.08 mM (n=3). The result obtained here was in agreement with other methods reported in relevant literature [9,42], indicating that this work holds potential application for an useful noninvasive glucose detection method by monitoring salivary glucose level.…”

Continuous glucose monitoring systems in the service of artificial pancreas

“…This expansion generates an ultrasound pulse which can be measured. As the concentration of glucose is correlated with the thermal properties of the tissue, the glucose concentration can be evaluated [42].…”

U-shaped fiber-optic ATR sensor enhanced by silver nanoparticles for continuous glucose monitoring

“…However, the absorption spectrum of urea, urea acid, creatinine, phosphate and other materials in blood or interstitial fluid overlapped with the glucose absorption spectrum (Jax et al, 2011;Martin et al, 2005), which is the biggest challenge for glucose monitoring using spectral method, especially for single or two wavelengths spectrometer. Therefore, at least 3-5 working wavelengths were needed to overcome the spectral interference presented by other substances and achieve high-precision glucose monitoring from ISF using spectral analysis (Pleitez et al, 2012;Vrančić et al, 2011). In this paper, five emission wavelengths, 1081, 1076, 1051, 1041 and 1037 cm À 1 , in the glucose "finger print" band were tuned and stabilized as the working wavelengths for glucose monitoring.…”