中文说明：
使用阈值法对脉搏信号的峰值进行提取，并且通过提取信号的峰值求脉搏信号的周期，并且简单判断脉搏信号的峰值是否可用。
English Description：
Using the threshold method to extract the peak value of the pulse signal, and by extracting the peak value of the signal to calculate the cycle of the pulse signal, and simply judge whether the peak value of the pulse signal is available.