Shirbani Fatemeh, Blackmore Conner, Kazzi Christina, Tan Isabella, Butlin Mark, Avolio Alberto P
Annu Int Conf IEEE Eng Med Biol Soc. 2018 Jul;2018:3639-3641. doi: 10.1109/EMBC.2018.8513058.
Estimating blood pressure (BP) from pulse arrival time (PAT) by image-based (skin video) photoplethysmography (iPPG) is of increasing interest due to the non-contact method advantage (over cuff-based methods) and potential for BP measurement to be built into portable devices such as mobile phones. The relationship between pulse transit time extracted from iPPG has been investigated during stable BP. The sensitivity of beat-to-beat iPPG-PAT to dynamic changes in BP has not been explored. This study investigated the correlation between iPPG-PAT and diastolic BP (DBP) during 1-minute seated rest and 3-minute isometric handgrip exercise. 15 healthy participants (9 female, 34±13 years) were recruited. Video was recorded from subjects' faces at 30 frames per second using a standard web-camera with simultaneous measurement of the electrocardiogram and noninvasive finger BP. The iPPG waveform was from the averaged green channel intensity of regions of the forehead or cheek. PAT was calculated from the R-wave ofthe electrocardiogram to the foot of the iPPG or finger BP waveform respectively for direct comparison. Handgrip exercise caused a steady increase in DBP (75±9 to 87±13 mmHg, p<0.001). Beat-to-beat iPPG-PAT and DBP was negatively correlated (mena ±SE -1.33±1.70 ms/mmHg, P=0.0024) as was finger-PAT (mean ±SE -0.5S ±0.39 ms/mmHg, P<0.001). The proportion of individual significant negative regression slopes between DBP and finger-PAT and between DBP and iPPG-PAT was not significantly different. Despite high variability of the correlation between iPPG-PAT and DBP among subjects, iPPG-PAT can track dynamic changes in BP.
基于图像（皮肤视频）的光电容积脉搏波描记法（iPPG）通过脉搏到达时间（PAT）来估计血压（BP），由于其具有非接触式方法的优势（相对于基于袖带的方法）以及有望将血压测量功能集成到手机等便携式设备中，因此越来越受到关注。在血压稳定期间，已经对从iPPG中提取的脉搏传输时间之间的关系进行了研究。但尚未探讨逐搏iPPG - PAT对血压动态变化的敏感性。本研究调查了在1分钟坐姿休息和3分钟等长握力运动期间iPPG - PAT与舒张压（DBP）之间的相关性。招募了15名健康参与者（9名女性，年龄34±13岁）。使用标准网络摄像头以每秒30帧的速度记录受试者面部的视频，同时测量心电图和无创手指血压。iPPG波形来自前额或脸颊区域的平均绿色通道强度。分别从心电图的R波到iPPG波形或手指血压波形的波谷计算PAT，以便进行直接比较。握力运动导致DBP稳步升高（从75±9 mmHg升至87±13 mmHg，p<0.001）。逐搏iPPG - PAT与DBP呈负相关（均值±标准误为 - 1.33±1.70 ms/mmHg，P = 0.0024），手指PAT也是如此（均值±标准误为 - 0.58±0.39 ms/mmHg，P<0.001）。DBP与手指PAT以及DBP与iPPG - PAT之间个体显著负回归斜率的比例没有显著差异。尽管受试者之间iPPG - PAT与DBP之间的相关性存在很大差异，但iPPG - PAT仍可追踪血压的动态变化。
