自适应脉搏氧系统设计与实现

Design and implementation of adaptive pulse oximetry

介绍一种自适应脉搏氧测量系统,使用模拟开关切换反馈电阻阻值,粗调系统增益;通过前级反馈调节MCU的DA输出,改变恒流驱动大小,微调系统增益。在两种机制协调下,实现系统增益精确控制,实现信号的宽范围测量,满足在低灌注指数下对弱脉搏的信号采集,并实现脉率、灌注指数、血氧饱和度的精确计算。

An adaptive pulse oximetry is introduced in the study.The system uses an analog switch to change the resistance of the feedback resistor for the coarse-tuning of system gain,and changes the DA output of MCU through controlling the feedback of the preamp circuitry to change constant current drive size,thus completing the fine-tuning of system gain.Under the coordination of two kinds of mechanisms,the proposed pulse oximetry has the abilities of controlling system gain precisely and measuring wide-range signals.Therefore,the pulse oximetry can realize the acquisition of weak pulse signals and the accurate calculations of pulse rate,perfusion index and blood oxygen saturation under hypoperfusion.