非接触生命参数检测系统自抖动干扰的自适应对消研究

非接触生命参数检测系统可以不接触人体、隔一定的距离检测重要的生命参数 ,如呼吸、心跳等。实际检测中 ,由各种因素所引起的系统本身的自抖动干扰 ,使检测信噪比大大降低 ,本文讨论了一种基于时变步长L MS算法的自适应技术来对消系统的自抖动干扰 ,提出了用附加振动传感器来提取自抖动干扰参考信号的方法 ,并研究了算法的最佳参数。研究结果表明这种方法收敛速度快 ,能有效的对消自抖动干扰

Study on Eliminating Self-dithering Interference of the System for Non-contact Detecting Life Parameters Based on an Adaptive Algorithm

The non-contact life parameters detecting systems can detect many important life parameters such as heartbeat and breathing at certain distance. In practice, the self-dithering interference of the system is produced by some factors; it makes the signal-to-noise ratio (SNR) of the recorded signal lower. This paper is discussed an adaptive technology based on a variable step-size LMS algorithm, which is used to eliminate the self-dithering interference of the system and hence to raise the SNR of the detecting signal. A method to obtain the reference signal by vibration sensor is brought forward and the optimum parameters settings are discussed.The results show that the reference signal is an integral part of output signal of the vibration sensor and has a relationship with the setting direction of the sensor. The conclusion is that the method is effective and feasible; also the algorithm is well convergent.