A low pass filter was designed and the simulated result from ORCAD shows that this filter is preferable to gain low-frequent FHR signal.

• 设计了加速度信号低通滤波放大电路并在ORCAD上进行了仿真,仿真结果表明该低通滤波电路能够较好的得到低频率胎心率信号。