So it is necessary to find a way to constrain the self - dithering interference of the non - contact life - detection system and raise snr so as to extract the life - parameter signal of human subject 因此,必须设法抑制由于外界作用而使非接触生命参数检测系统产生的自抖动干扰,提高信噪比,检测出人体的生命参数信号。