Shao Dangdang, Yang Yuting, Liu Chenbin, Tsow Francis, Yu Hui, Tao Nongjian
IEEE Trans Biomed Eng. 2014 Nov;61(11):2760-7. doi: 10.1109/TBME.2014.2327024.
We present optical imaging-based methods to measure vital physiological signals, including breathing frequency (BF), exhalation flow rate, heart rate (HR), and pulse transit time (PTT). The breathing pattern tracking was based on the detection of body movement associated with breathing using a differential signal processing approach. A motion-tracking algorithm was implemented to correct random body movements that were unrelated to breathing. The heartbeat pattern was obtained from the color change in selected region of interest (ROI) near the subject's mouth, and the PTT was determined by analyzing pulse patterns at different body parts of the subject. The measured BF, exhaled volume flow rate and HR are consistent with those measured simultaneously with reference technologies (r = 0.98, for HR; r = 0.93, for breathing rate), and the measured PTT difference (30-40 ms between mouth and palm) is comparable to the results obtained with other techniques in the literature. The imaging-based methods are suitable for tracking vital physiological parameters under free-living condition and this is the first demonstration of using noncontact method to obtain PTT difference and exhalation flow rate.
我们展示了基于光学成像的方法来测量重要的生理信号，包括呼吸频率（BF）、呼气流量、心率（HR）和脉搏传输时间（PTT）。呼吸模式跟踪基于使用差分信号处理方法检测与呼吸相关的身体运动。实施了一种运动跟踪算法来校正与呼吸无关的随机身体运动。心跳模式从受试者嘴巴附近选定感兴趣区域（ROI）的颜色变化中获取，PTT通过分析受试者不同身体部位的脉搏模式来确定。测量得到的BF、呼出体积流量和HR与使用参考技术同时测量的结果一致（HR的r = 0.98；呼吸频率的r = 0.93），并且测量得到的PTT差异（嘴巴和手掌之间为30 - 40毫秒）与文献中其他技术获得的结果相当。基于成像的方法适用于在自由生活条件下跟踪重要的生理参数，这是首次展示使用非接触方法获得PTT差异和呼气流量。
