光调制技术用于提高光谱法舌诊的测量信噪比

为了解决光谱采集受环境光干扰严重的问题,首次将光调制技术用于提高光谱法舌诊测量的信噪比。系统采用调制盘对参考光信号强度进行调制,运用此装置采集同一被测体在分别叠加绿色、紫色、红色激光以及自然环境光干扰情况下的反射光谱,对采集来的数据运用离散傅里叶变换进行解调,提取最大谐波分量,然后对提取的最大谐波分量进行归一化,绘制解调后的光谱曲线,通过比较发现,不同干扰情况下所测同一被测体经过调制解调后的反射光谱曲线走向基本一致,结果表明光调制技术能够去除舌体反射光谱采集中环境杂散光的干扰,为高信噪比舌诊光谱数据采集提供了一种新途径。

Improving the signal to noise ratio of spectroscopy for tongue inspection by optical modulation

In order to solve the problem that the collected spectrum was influenced seriously by the environment light, optical modulation was used to improve the signal to noise ratio of spectroscopy-tongue inspection for the first time. First, reference light was modulated by reticle in this system; second, the reflect spectrum of the same measured object was collected under the condition that it was influenced by green, purple, red laser and environment light respectively; thirdly, the DFT was used to demodulate the collected spectrum data; the maximum harmonic components were extracted and normalized, then the spectral curve was drawn; by comparison, the spectral curves of the same measured object under different condition were almost the same. The experiment result showed that the optical modulation can remove the influence of the environment light; and this method can provide a new way to improve the signal to noise ratio of spectroscopy for tongue inspection.