Development of dynamics preserving method for extraction of imaging photoplethysmogram signal from a conventional camera's video recordings.

在2022财年，进一步研究了光体积图信号的动力学。对数据采集参数的影响进行了深入的研究，如时间序列长度和抽样。结果表明，由非线性时间序列分析提取的动态特征与时间序列长度和采样率之间存在一定的相关性。此外，还发现所获得的结果可以用于检测可靠的特征提取所需的最小时间序列长度。此外，这些结果在复杂的非线性模型上得到了验证，因此，这些结果可以推广到除光体积图之外的其他非线性复信号。此外，本文还研究了FY成像的光体积图(IPPG)信号。首先，成功地从从iPad摄像头获得的视频记录中提取了iPPG信号。然后对其动力学特性进行了研究。结果显示，由传统脉搏血氧仪记录的参考信号与从iPad摄像头提取的信号具有显著的相似性。这揭示了智能手机/iPad相机可以用来记录具有与传统脉搏血氧仪相似的动态特性的光体积图信号，从而使基于光体积图的健康监测应用成为可能，例如生理和心理健康监测，而不需要任何专门的设备。

In FY 2022, the dynamics of the photoplethysmogram signals were furtherly investigated. Thoughtful investigation of the data collection parameters effects, such as time series length and sampling, were studied. The results demonstrated the dependence of the dynamical characteristics, extracted by nonlinear time series analysis, from the time series length and sampling rate. Moreover, it was found that the obtained results can be used to detect the minimal time series length required for reliable feature extraction. Furthermore, these results were validated on complex nonlinear models; thus, these results' applicability can be extended to other nonlinear complex signals besides the photoplethysmogram.Additionally, in this FY imaging photoplethysmogram (iPPG) signals were investigated. First, iPPG signals were successfully extracted from video recordings obtained from an iPad camera. Then its dynamical characteristics were investigated. The results demonstrated significant similarities between reference signals recorded by a conventional pulse oximeter and signals extracted from an iPad camera. This unveils that a smartphone/iPad camera can be used to record photoplethysmographic signals with dynamical characteristics similar to those of conventional pulse oximeters, thus enabling possibilities for photoplethysmogram-based health monitoring applications, such as physiological and mental health monitoring, without any specialized devices.