McDuff Daniel, Gontarek Sarah, Picard Rosalind W
IEEE Trans Biomed Eng. 2014 Dec;61(12):2948-54. doi: 10.1109/TBME.2014.2340991. Epub 2014 Jul 24.
We present a new method for measuring photoplethysmogram signals remotely using ambient light and a digital camera that allows for accurate recovery of the waveform morphology (from a distance of 3 m). In particular, we show that the peak-to-peak time between the systolic peak and diastolic peak/inflection can be automatically recovered using the second-order derivative of the remotely measured waveform. We compare measurements from the face with those captured using a contact fingertip sensor and show high agreement in peak and interval timings. Furthermore, we show that results can be significantly improved using orange, green, and cyan color channels compared to the tradition red, green, and blue channel combination. The absolute error in interbeat intervals was 26 ms and the absolute error in mean systolic-diastolic peak-to-peak times was 12 ms. The mean systolic-diastolic peak-to-peak times measured using the contact sensor and the camera were highly correlated, ρ = 0.94 (p 0.001). The results were obtained with a camera frame-rate of only 30 Hz. This technology has significant potential for advancing healthcare.
我们提出了一种使用环境光和数码相机远程测量光电容积脉搏波信号的新方法，该方法能够（在3米的距离）准确恢复波形形态。特别是，我们表明，利用远程测量波形的二阶导数可以自动恢复收缩期峰值与舒张期峰值/拐点之间的峰峰值时间。我们将面部测量结果与使用接触式指尖传感器捕获的结果进行比较，结果表明在峰值和时间间隔方面高度一致。此外，我们还表明，与传统的红、绿、蓝通道组合相比，使用橙色、绿色和青色通道可显著改善测量结果。心跳间隔的绝对误差为26毫秒，平均收缩期-舒张期峰峰值时间的绝对误差为12毫秒。使用接触式传感器和相机测量的平均收缩期-舒张期峰峰值时间高度相关，ρ = 0.94（p < 0.001）。这些结果是在相机帧率仅为30Hz的情况下获得的。这项技术在推进医疗保健方面具有巨大潜力。
