血氧饱和度测量的新方法及其实现研究

Measurement of blood oxygen saturation has vital guidance value for disease diagnosis, health assessment and clinical monitoring. The existing oximeters only measure the blood oxygen saturation of human extremities, but cannot deal with the deep tissues or organs. What's more, they are unable to handle the problems effectively, such as low perfusion, motion artifact, ambient light interference, etc. The aim of this project is to develop a device which can measure the blood oxygen saturation of the deep tissues and organs accurately. We will utilize a novel method to deal with the problems mentioned above. Firstly, we will adopt Monte Carlo method to simulate the process of photons non-linearly transport in tissue. After that, the non-linear Beer-Lambert equation and algorithm are established. Secondly, we will develop a measurement device based on the model established above. This device will utilize two key techniques: (1) utilizing the PWM (pulse width modulation) amplifier and phase detector to cope with low perfusion problem; (2) utilizing Adaptive Interference cancellation technology to cope with ambient light and motion artifact problems. Lastly, we will carry out experimental verification and rectify the model, thus, realize measurement accurately. This project has a profound significance to our country's economic development and the improvement of Chinese people's health level.

血氧饱和度测量对人体疾病诊断、健康评价、临床监护具有重要医学价值。已有的血氧仪只能测量人体肢体末端(如手指、脚指、耳垂、鼻翼等)的血氧饱和度，无法测量深部组织和器官的局部血氧饱和度，并且现有技术无法有效处理低灌注、运动伪迹、环境光干扰等问题。本项目旨在研制人体深部组织和器官的血氧饱和度精确测量装置，重点对低灌注、运动伪迹和环境光干扰问题的解决提出创新性的方法。在利用模特卡罗方法模拟、推导、建立用于反射式深层局部血氧饱和度检测的比尔-朗伯特方程与算法基础上，研制反射型深层局部血氧饱和度测量装置，该装置拟采用的关键技术：(1)采用脉宽调制放大和相位检测技术来解决低灌注和断层选择的问题；（2）采用自适应对消技术解决信号的环境光干扰和运动伪迹的问题；(3)进行实验验证、校正模型，实现血氧饱和度的精确测量。本项目的研究对血液成分无创检测技术、国民健康水平的提高均具有重要意义。

血氧饱和度测量对人体疾病诊断、健康评价、临床监护具有重要医学价值。已有的血氧饱和度检测仪无法测量深部组织和器官的局部血氧饱和度，并且现有技术无法有效处理低灌注、运动伪迹、环境光干扰等问题。本课题建立了光子与组织相互作用的模型，并通过Monte Carlo计算机仿真实验得出光源探测器距离与出射光强度的关系曲线，并根据修正的Lambert-Beer定律提出了基于多路PPG信号的数学模型。构建了多路PPG信号采集系统平台，主要包括：反射式传感器探头的设计与制作、模拟前端信号采集和处理模块设计与实现、上位机数据采集存储模块的实现，利用该系统平台完成了人体不同部位的PPG信号采集。针对运动伪迹消除的问题，提出独立成分分析与自适应滤波相结合的方法和基于梳状滤波器滤波的方法，通过对仿真数据与真实PPG信号进行处理实验，证明此两种方法均能够有效滤除运动伪迹。本课题完成了乳腺肿块筛查探头的结构设计，并实现了反射式深层局部血氧饱和度测量装置原理样机的研制。