Modelling, verification, and calibration of a photoacoustics based continuous non-invasive blood glucose monitoring system

Abstract

This paper examines the use of photoacoustic spectroscopy (PAS) at an excitation wavelength of 905 nm for making continuous non-invasive blood glucose measurements. The theoretical background of the measurement technique is verified through simulation. An apparatus is fabricated for performing photoacoustic measurements in vitro on glucose solutions and in vivo on human subjects. The amplitude of the photoacoustic signals measured from glucose solutions is observed to increase with the solution concentration, while photoacoustic amplitude obtained from in vivo measurements follows the blood glucose concentration of the subjects, indicating a direct proportionality between the two quantities. A linear calibration method is applied separately on measurements obtained from each individual in order to estimate the blood glucose concentration. The estimated glucose values are compared to reference glucose concentrations measured using a standard glucose meter. A plot of 196 measurement pairs taken over 30 normal subjects on a Clarke error grid gives a point distribution of 82.65% and 17.35% over zones A and B of the grid with a mean absolute relative deviation (MARD) of 11.78% and a mean absolute difference (MAD) of 15.27 mg/dl (0.85 mmol/l). The results obtained are better than or comparable to those obtained using photoacoustic spectroscopy based methods or other non-invasive measurement techniques available. The accuracy levels obtained are also comparable to commercially available continuous glucose monitoring systems.

Extended Near-Infrared Optoacoustic Spectrometry for Sensing Physiological Concentrations of Glucose

“…Among non-invasive techniques proposed for in vivo glucose measurements, those using spectroscopic modalities, such as fluorescence spectroscopy, NIR, or MIR spectroscopies show clear promise ( 20 , 22 , 24 , 25 ). However, the pending weaknesses of the pure optical methods related to photon scattering impede accurate spectral discrimination and quantification ( 26 , 27 ).…”

In vivo Microscopic Photoacoustic Spectroscopy for Non-Invasive Glucose Monitoring Invulnerable to Skin Secretion Products

“…To the best of our knowledge, this is the first report on the microscopic position scanning of spectral signals for non-invasive glucose measurements. Our method was an improvement over most of the previously reported methods 13 , 14 , 36 – 39 , and performed worse than several previous approaches such as Raman Spectroscopy 15 and photoacoustic spectroscopy 40 . However, skin secretion products and the microscopic structure of the skin tissues were not explored in previous invasive-glucose-sensing studies.…”

Performance Enhancement of Opened Resonance Photoacoustic Cells Based on Three Dimensional Topology Optimization

“…Photoacoustic spectroscopy (PAS) is a typical analytical tool employed to probe the information of chemical composites by measuring the optical absorption characteristics of samples [1][2][3][4][5]. This technology has the advantages of high sensitivity, high selectivity, rapid response, and high precision, which are essential for online monitoring.…”