近红外组织血氧检测的波长优化及实验验证

Wavelength Optimization and Experimental Validation of Near-Infrared Tissue Oxygenation Detection

基于近红外光谱技术的组织血氧参数检测具有快速、实时、无创等优点,已经广泛应用于临床,具有重要的应用价值。近红外光谱组织血氧检测技术需要不同波长的近红外光进行组合来计算氧合血红蛋白和还原血红蛋白的浓度,但是目前用来检测血氧信息的波长组合并不统一。光源波长选择直接关系到组织血氧参数提取的准确性。为提高测量精度,本研究建立了一种基于条件数的波长选择方法并通过组织仿体实验和在体实验进行实验验证。实验结果表明:当改变组织仿体的吸收和散射系数时,最小条件数组反演的总血红蛋白浓度误差最小,最大条件数组反演的误差最大;在体实验中,对收集的光谱信号去噪处理后,条件数最小组反演的血氧饱和度误差小,最大条件数组反演的氧饱和度误差最大,符合条件数的基础理论。因此,使用条件数的方法进行波长优化选择是可行的,提高了光学参数反演成生理参数过程中对误差的容忍程度,为组织血氧检测的波长合理选择提供了方法基础。

Tissue oximetry parameter detection based on nearinfrared spectroscopy has the advantages of being rapid,realtime,and noninvasive,and has been widely used in clinics with important application values.Nearinfrared spectroscopic tissue oximetry requires a combination of different wavelengths of nearinfrared light to calculate the concentration of oxyhaemoglobin and reduced haemoglobin,but the combination of wavelengths currently used to detect oximetry information is not uniform.The wavelength selection of the light source is directly related to the accuracy of the extraction of tissue blood oxygenation parameters.In order to improve the measurement accuracy,a wavelength selection method based on condition number was established in this study and experimentally verified by tissue mimicry and in vivo experiments.The experimental results show that when the absorption and scattering coefficients of tissue mimics are changed,the error of total haemoglobin concentration calculated by the smallest conditioned number group is the smallest,and the error calculated by the largest conditioned number group is the largest.In the in vivo experiment,when the collected spectral signals were denoised,the smallest conditioned number group calculated oxygen saturation with small error and the largest conditioned number group inverted oxygen saturation with the largest error,which is in accordance with the underlying theory of conditioned numbers.Therefore,it is feasible to optimize and select the wavelength using the conditional number method, which improves the tolerance of error in the calculation of optical parameters into physiological parameters, and provides a methodological basis for the rational selection of wavelength for tissue blood oxygen detection.