单波长光声光谱血氧饱和度检测技术研究

血氧饱和度(SO2)为临床观察病情变化提供了有意义的指标.传统血氧饱和度检测研究工作多采用双光源和多光源光电容积脉搏波描记法实现无创检测来减少病人痛苦.通过研究生物组织对光的吸收和散射特性,将光谱学和光声技术相结合提出了一种无创式单光源检测血氧饱和度(SO2)、脱氧血红蛋白浓度HBR]和氧合血红蛋白浓度HbO2]的新方法.该方法基于血液对光信号的吸收和散射理论基础和光声信号呈现吸收线形关系建立单波长光声光谱血氧饱和度检测技术,不仅可以进行指标性参数分析还可以对组织成像.为了验证该技术可行性,在实验中采用单波长激光脉冲光源,以绿色和红色墨水的混合液体作为含有脱氧血红蛋白和氧合血红蛋白的血液模型注入软管模拟人体血液环境.其中红色墨水的含量类比于血液中含氧血红蛋白含量,从而可通过测量计算出红色和绿色墨水浓度来表征伪血氧饱和度(poseudo-SO2).实验结果表明,所测的伪血氧饱和度与实际浓度误差不超过6.97％,采用该方法量化血氧饱和度是可行的;同时利用实验结果,结合光声成像技术完成了对伪血液中单圆管截面成像.该方法替代多波长光谱分析的方法能显著降低激光系统和便携式实现成本.

Single-Wavelength Oxygen Saturation Detection Fusing OpticalAbsorption and Scattering Properties: A Phantom Study

Oxygen saturation(SO2)for clinical observation of the disease changes provides a meaningful indicator.Traditional oxygen saturation analyses adopt the dual-wavelength and multi-wavelength photoplethysmography to achieve non-invasive detection to reduce the pain of patients.In this paper,a novel approach combining single wavelength laser optical absorption induced photoacoustic and optical scattering,was developed to noninvasively measure blood oxygen saturation,the concentration of deoxygenated haemoglobin(HbR)and oxyhemoglobin(HbO2).A theoretical derivation between the absorption and scattering light characteristics and linear relationship of photoacoustic spectroscopy built the single-wavelength oxygen saturation detection technology,so parameters analysis and imaging of tissue could also be obtained.Here,the phantom experiment successfully demonstrated the quantization of the concentration of a dual-ink combined with green-red ink imitating a blood with hemoglobin and oxygenated hemoglobin.The proportion of red ink,that is to say,pseudo-SO2 was measured with experimental errorless than 6.97％.Then the pseudo-SO2 was imaged in the single tube cross-section for blood vessel copy.Unlike conventional multi-wavelength photoacoustic or near infrared spectroscopy approaches,the proposed single-wavelength method significantly lowers the cost of laser system and portable implementations.