研究了一种近红外光谱抗扰动脑血氧分析仪, 用于解决常规脑血氧测试方法检测过程复杂、抗干扰措施繁琐等问题。分析与探讨了影响脑血氧检测精度的因素, 选择了合适的三波长近红外探测光源(735 nm/805 nm/850 nm)用于该系统。利用氧合血红蛋白和还原血红蛋白在近红外光波段的吸收特性, 得到这两种物质的浓度变化量, 推算出了影响血氧检测精度的源端干扰表达式。同时, 在检测端同步检测环境光, 消除了漏光干扰。最后对上位机得到的原始数据与干扰数据进行处理, 实现对大脑前额叶脑血氧波动的实时监测。设计了屏气实验以及源端干扰实验, 检验了仪器实验结果的正确性。结果表明: 本文所设计的脑血氧分析仪可以有效地检测血红蛋白的变化并能通过源端校正算法抑制源端干扰, 干扰抑制比可达70%以上, 基本实现了对人体无创、实时、准确监测的目的。

A sort of anti-disturbance cerebral oxygen analyzer based on near-infrared spectroscopy was researched to improve conventional test methods in complex measuring process and tedious anti-jamming treatment. Some effect factors on cerebral oxygen measuring accuracy were analyzed and a proper three-wavelength near-infrared detection light source (735nm/805nm/850nm)was selected to use in the system. On the basis of the absorptivities of HbO2 and HbR in the near- infrared spectra, the variation of the two substance's concentration was received, and a source interference expression resulted from the impact of oxygen detection accuracy was calculated. Meanwhile, the ambient light was detected in the terminal simultaneously to eliminate the interference from leaked light. Finally, the original data from a upper computer and the interference data were processed to realize the real-time monitoring of the blood-oxygen fluctuation in the prefrontal lobe of the brain. A breathlessness experiment and a source interference experiment were performed and the correctness of instrument was verified. The experimental results show that the cerebral oxygen analyzer designed in this paper detects the changes of hemoglobin and eliminates the interference of the source effectively by the proposed anti-disturbance algorithm, and the correcting interference error is about 70% or more, which implements noninvasive, real time and correct monitoring for human body.