基于心冲击描记术的心率检测方法

Measurement of Heart Rate Based on Ballistocardiography

非接触式心冲击描记术(BCG)通过测量血液循环过程中血液对血管壁产生的周期性压力来测量心率。这种压力会引起包括头部在内的身体各部位周期性弱机械运动,这种运动十分微弱,并且从身体运动中提取的BCG信号有着较低的信噪比,限制了其心率的测量精度。利用光学杠杆放大头部运动(Optical lever amplified BCG,OLA-BCG),提出了一种非接触式高精度心率检测算法。该方法以激光作为主动光源,结合附着在头部的平面镜,实现头部运动的放大;同时利用加权质心跟踪算法提取头部运动轨迹并采用独立成分分析过滤掉干扰噪声,得到BCG信号。最后,对提取的BCG信号进行频谱分析,计算出心率值。实验结果表明,OLA-BCG方法可以有效提高从头部运动中提取的BCG信号的信噪比和心率的测量精度。

Non-contact ballistocardiography(BCG) is used to measure heart rate(HR) by measuring the periodic pressure of blood on the walls of blood vessels during circulation. This pressure causes the periodic weak mechanical movement of various parts of the body, including the head, which is very weak, and the BCG signal extracted from the body movement has a low signal-to-noise ratio, which limits the measurement accuracy of the heart rate. An optical lever is used to amplify the head motion, and a non-contact high precision heart rate detection algorithm named optical lever amplified BCG algorithm(OLA-BCG) is proposed. In the proposed method, a laser is used as the active light source. A plane mirror attached to the head is used to amplify the head motion. At the same time, the weighted centroid tracking algorithm is used to extract the motion trajectory of the head, and the interference noise is filtered out by independent component analysis to obtain BCG signal. Finally, the extracted BCG signal is analyzed and the heart rate is calculated. Experimental results show that the proposed OLA-BCG can effectively improve the signal-to-noise ratio and measurement accuracy.