Peng Rong-Chao, Zhou Xiao-Lin, Lin Wan-Hua, Zhang Yuan-Ting
Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, 1068 Xueyuan Road, Xili Nanshan, Shenzhen, Guangdong 518055, China ; Shenzhen College of Advanced Technology, University of Chinese Academy of Sciences, 1068 Xueyuan Road, Xili Nanshan, Shenzhen, Guangdong 518055, China ; Key Laboratory for Health Informatics of the Chinese Academy of Sciences (HICAS), 1068 Xueyuan Road, Xili Nanshan, Shenzhen, Guangdong 518055, China.
Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, 1068 Xueyuan Road, Xili Nanshan, Shenzhen, Guangdong 518055, China ; Key Laboratory for Health Informatics of the Chinese Academy of Sciences (HICAS), 1068 Xueyuan Road, Xili Nanshan, Shenzhen, Guangdong 518055, China.
Comput Math Methods Med. 2015;2015:516826. doi: 10.1155/2015/516826. Epub 2015 Jan 12.
Heart rate variability (HRV) is a useful clinical tool for autonomic function assessment and cardiovascular diseases diagnosis. It is traditionally calculated from a dedicated medical electrocardiograph (ECG). In this paper, we demonstrate that HRV can also be extracted from photoplethysmograms (PPG) obtained by the camera of a smartphone. Sixteen HRV parameters, including time-domain, frequency-domain, and nonlinear parameters, were calculated from PPG captured by a smartphone for 30 healthy subjects and were compared with those derived from ECG. The statistical results showed that 14 parameters (AVNN, SDNN, CV, RMSSD, SDSD, TP, VLF, LF, HF, LF/HF, nLF, nHF, SD1, and SD2) from PPG were highly correlated (r > 0.7, P < 0.001) with those from ECG, and 7 parameters (AVNN, TP, VLF, LF, HF, nLF, and nHF) from PPG were in good agreement with those from ECG within the acceptable limits. In addition, five different algorithms to detect the characteristic points of PPG wave were also investigated: peak point (PP), valley point (VP), maximum first derivative (M1D), maximum second derivative (M2D), and tangent intersection (TI). The results showed that M2D and TI algorithms had the best performance. These results suggest that the smartphone might be used for HRV measurement.
心率变异性（HRV）是一种用于自主神经功能评估和心血管疾病诊断的有用临床工具。传统上，它是通过专用的医学心电图仪（ECG）计算得出的。在本文中，我们证明HRV也可以从智能手机摄像头获取的光电容积脉搏波图（PPG）中提取。从智能手机采集的PPG中计算出16个HRV参数，包括时域、频域和非线性参数，并与从ECG得出的参数进行比较。统计结果表明，PPG中的14个参数（平均NN间期（AVNN）、标准差NN间期（SDNN）、变异系数（CV）、相邻NN间期差值的均方根（RMSSD）、差值的标准差（SDSD）、总功率（TP）、极低频功率（VLF）、低频功率（LF）、高频功率（HF）、LF/HF比值、归一化低频功率（nLF）、归一化高频功率（nHF）、SD1和SD2）与ECG中的参数高度相关（r > 0.7，P < 0.001），并且PPG中的7个参数（AVNN、TP、VLF、LF、HF、nLF和nHF）在可接受范围内与ECG中的参数具有良好的一致性。此外，还研究了五种不同的算法来检测PPG波的特征点：峰值点（PP）、谷值点（VP）、最大一阶导数（M1D）、最大二阶导数（M2D）和切线交点（TI）。结果表明，M2D和TI算法性能最佳。这些结果表明智能手机可能可用于HRV测量。
