光学 精密工程, 2015, 23 (9): 2698, 网络出版: 2015-10-22
由可见光谱视频中提取心率的对角累积量法
Extracting heart rate from visible spectrum video based on diagonal cumulant algorithm
光电容积脉搏波 心率检测 对角累积量算法 联合近似特征对角化 Photoplethysmography(PPG) heart rate detection diagonal cumulant algorithm Joint Approximate Diagonalization of Eigenmatrice(
摘要
由于使用经典的联合近似特征对角化(JADE)算法从视频中估计光电容积脉搏波(Photoplethysmography,PPG)信号,再经快速傅里叶变换转化成的心率值与真实心率值的误差较大,本文提出使用基于对角累积量算法从视频中分离PPG信号,再经过快速傅里叶变换转换成心率的方法来提高心率测量的准确性。进行了从RGB彩色可见光视频信号中恢复心率值的实验。对比实验表明,基于对角累积量分离算法所得心率值与真实心率值差的绝对值的统计特征参数较JADE算法均有所降低,均值、标准差、均方根误差平均分别下降1.46,4.98和4.49。通过Bland-Altman图的分析表明,在95%的置信区间内,对角累积量算法所得心率的浮动范围较JADE算法减小了2倍以上,显示对角累积量算法具有更高的估计精度,对肤色亮度和外界自然光的要求更低,通过调整参数值,可使运行时间控制在1 s之内,基本满足实时提取心率的要求。
Abstract
Photoplethysmography(PPG) signal is usually acquired from a video image by using the classic Joint Approximate Diagonalization of Eigenmatrices(JADE) algorithm,and the heart rate is extracted from PPG signal using Fast Fourier Transform. However,the obtained value has larger deviation with the actual heart rate value. To improve the accuracy of measured results,a new blind source separation algorithm was proposed. The algorithm used diagonal cumulant to separate the PPG signal,and took the Fast Fourier Transform to extract the heart rate. Experiments were carried out by utilizing visible spectrum color video. Compared with the JADE algorithm,the results show that statistical parameter values of the absolute difference between heart rate values extracted from the diagonal cumulant algorithm and the actual heart rate values are decreased. The mean value,standard deviation,and root-mean-square deviation has reduced by 1.46,4.98 and 4.49,respectively. By analytical form of the Bland-Altman graph,the floating range of diagonal cumulant algorithm reduces more than twice as compared with the JADE method in a 95% confidence interval. It suggests that diagonal cumulant algorithm provides higher estimated accuracy,and relies less on intensity of skin and natural light. The calculation time can also be controlled less than 1 s after dramatically reducing the iterations by adjusting the parameter values in diagonal cumulant algorithm,which meets the demand of real-time electrocardiogram signal extraction.
王蒙军, 王楠, 王霞, 付晓静, 李刚. 由可见光谱视频中提取心率的对角累积量法[J]. 光学 精密工程, 2015, 23(9): 2698. WANG Meng-jun, WANG Nan, WANG Xia, FU Xiao-jing, LI Gang. Extracting heart rate from visible spectrum video based on diagonal cumulant algorithm[J]. Optics and Precision Engineering, 2015, 23(9): 2698.