Photoacoustic detection of glucose based on the pulsed laser induced ultrasonic combined with scanning position method

摘要

In order to accurately measure the glucose concentration, the photoacoustic spectroscopy combined with the scanningposition method was used in this paper. Meanwhile, a kind of custom-built photoacoustic detection system wasestablished. In this system, a 532nm pumped OPO pulsed laser was used as the excitation source, and a non-focusedultrasonic detector was used to capture the photoacoustic signals of phantom and glucose. To improve the measurementaccuracy of glucose by using the photoacoustic spectroscopy, a scanning sub-system was established to accurately locatethe position of the simulated vessel. In the experiments, to simulate the bio-tissue and the blood vessel in human body, aspecimen made of agar block with a carbon bar and a silicon gel pipe was prepared to verify the availability andfeasibility of the established photoacoustic detection system. According to the obtained photoacoustic peak-to-peakvalues of the specimen by scanning method, the position of the carbon bar and the silicon gel pipe in the specimen can belocated. Then, to test the photoacoustic detection of glucose in the silicon gel pipe, a cycling sub-system was used tosimulate the blood flow in the blood vessel. Based on the located position of the silica gel pipe, the focused laser spotwas shifted and accurately irradiated into the silica gel pipe to induce the photoacoustic signals of glucose. By mean ofthe photoacoustic system, several different concentrations of glucose solutions were test, and the time-resolvedphotoacoustic signals and peak-to-peak values of glucose are all obtained. The prediction model of glucose concentrationwas established by using the linear fitting method. At the same time, the predicted result was compared with that of theglucose in the agar specimen. Results show that the novel photoacoustic detection of glucose is available. The correctioncoefficient of the glucose concentration prediction was improved by using the photoacoustic spectroscopy combined withthe scanning position method.