基于AVR单片机的光频式脉搏血氧仪设计

Design of Light-Frequency Converting Pulse Oximeter based on AVR Microprocessor

总结了一种以AVR单片机为硬件核心结合高抗干扰能力光-频转换传感器TSL237的光频式脉搏血氧仪软硬件设计.依据红外光谱法血氧饱和度的测量基本原理,采用H桥驱动电路来驱动双波长二极管,并应用宽监测范围光-频转换传感器TSL237将光照强度转换为频率信号,传输给AVR MEGA16处理器进行运算处理.AVR MEGA16处理器根据连续采样周期的脉冲计数平均值和每一采样周期脉冲计数值的变化量计算出血氧饱和度.相比传统的模拟电路检测方法,此设计具有电路结构简单,抗干扰能力强,血氧饱和度测量准确的特点.

A design of pulse oximeter is introduced based on the hardware platform of AVR microcontroller. A high anti-jamming capability optical frequency conversion sensor TSL237 is adopted. According to basic principle of infrared spectroscopy measuring oxygen saturation, the drive circuit of H-Bridge to drive dual-wavelength diode is used, and Light-to-Frequency Converter TSL237 is applied to convert light intensity to frequency signal. Then the frequency signal is transmitted to AVR MEGA16 for data processing. Microprocessor uses the pulse count average value of continuous sampling period and variation of the pulse count value of each sampiing period to calculate the oxygen saturation. Compared to the traditional method of analog circuits, the design has the advantages of simple structure, strong anti-interference ability and accurate measurement of blood oxygen saturation.