关于交直流电路的实时血氧检测系统设计

Design of Real-time Oxygen Detection System in AC and DC Circuits

针对血氧仪系统对血氧参量要求精确度高、抗干扰能力强和功耗低的设计要求,本文的信号放大设计部分采用了差分运放放大电路,提高了信号的信噪比,增大信号的共模抑制比.针对测量环境光的干扰,设计了一组交直流分离电路,可有效地硬件分隔红光和红外光,消除环境光的干扰,提高了系统的工作能力;同时采用微分阈值对血氧参量进行处理,使系统的信号实用性大大提高.整体设计方案的电路设计和实际测试结果证明了该方案的可行性和可靠性.

For the requirements for accuracy, anti-interference and power saving of oxygen system param-eters by oximeter, this paper proposes a signal amplification design by using a differential op amp ampli-fier circuit to enhance the signal to noise ratio and increase signal common mode rejection ratio.And be-cause of the measurement of ambient light interference, a set of AC-DC flow separation circuit is also de-signed which can effectively separate hardware red and infrared light, eliminate the interference of ambi-ent light and improve the working capacity of the system.Meanwhile using differential threshold amount to process oxygen parameters can improve the signal system greatly.Hence the circuit simulation and test results demonstrate the feasibility and reliability of the whole design.