因透射式血氧仪检测范围受限,根据反射式测量原理设计光电容积脉搏波探头检测模块,并采用MSP430超低功耗单片机结合血氧模拟前端AFE4490实现对光电容积脉搏波的采集。由MSP430控制AFE4490实现双波长发光管交替发光、数据采集以及放大滤波,并采用数字信号处理技术进行去噪工作。实验表明,所设计的反射式血氧检测系统能有效地检测指尖脉搏,处理得到的脉率和血氧参数误差在3%以内。
Because transmission pulse oximeter's detection range is limited,combining ultra-low power 430 single chip with analog front end AFE4490 to measure PPG,reflective probe module based on reflection measurement principle is designed.MSP430 controls AFE4490 to fulfill dual wavelength LED's function timing data acquisition and amplify and filter,then some digital signal processing method is used for signal de-noising.Experiments show that the reflectance oxygen saturation detecting system can moni-toring pulse effectively,and the error is within 3 %.