为了实现血糖无创在体检测, 解决测量灵敏度低、激励源波动影响大、病患体温干扰严重等难题, 本文提出一种基于温度补偿的差动光声测量方法, 该方法可以大幅度抑制温度的影响。采用两个相同的光声池分别容纳被测血液和纯水, 分别获取测量光声信号和参考光声信号。首先, 改变两个光声池的液体温度, 测定两路光声信号的温度系数; 然后, 分别对两路光声信号进行温度补偿和修正, 消除温度的影响; 最后将两路光声信号进行比值处理, 抑制光源强度波动的影响。在此基础上, 本文还使用组织工程皮肤安体肤来模拟人体皮肤环境, 探究皮肤对激光和光声信号的透过性。测试结果表明, 低浓度下葡萄糖光声信号强度和浓度的线性拟合直线的拟合度可以达到0.970 6, 证实了这种方法在实际应用中的可行性; 模拟皮肤的不同位置对激光的穿透率不同, 平均透光率为53.88%, 皮肤对光声信号的平均透过率为9450%。本文的研究结果可为血糖在体无创检测的实现提供有益借鉴。

To achieve non-invasive blood glucose in vivo detection, solving common problems such as low measurement sensitivity, large interference of excitation source fluctuation, and serious patient temperature interference is first necessary. In this study, a new method based on temperature compensation for differential photoacoustic measurement was proposed, which can greatly suppress the influence of temperature. Two identical photoacoustic cells were used, one for accommodating the blood to be measured, the other for pure water. Measured and reference photoacoustic signals are respectively obtained. First, the temperature coefficient of the two photoacoustic signals is determined by changing the liquid temperature of the two photoacoustic cells. Then, the error of temperature in the two photoacoustic signals are separately compensated and corrected to eliminate the interference of temperature on the experimental results. Finally, the intensity of one photoacoustic signal is divided by that of the other photoacoustic signal to suppress the influence of laser intensity fluctuation. Based on this procedures the study used tissue engineered skin to simulate a human skin environment and explored the skins permeability to laser and photoacoustic signals. The results show that the R2 of linear fitting between glucose photoacoustic signal intensity and glucose concentration under a low concentration was 0.970 6, thereby proving the feasibility of this method for use in practical applications. The results also show that the average transmittance of the simulated skin to laser was 53.88%, and the average transmittance of the simulated skin to the photoacoustic signal was 9450%. The results of this study can provide a useful reference for the noninvasive detection of blood glucose.