Nagoya Institute of Technology, Nagoya 466-8555, Japan.
Soken, Inc., Nisshin, Aichi 470-0111, Japan.
Sensors (Basel). 2021 Apr 13;21(8):2735. doi: 10.3390/s21082735.
Continuous monitoring of heart-rate is expected to lead to early detection of physical discomfort. In this study, we propose a non-contact heart-rate measurement method which can be used in an environment such as driver heart-rate monitoring with body movement. The method is based on the electric field strength transmitted through the human body that changes with the diastole and systole of the heart. Unlike conventional displacement detection of the skin surface, we attempted to capture changes in the internal structure of the human body by irradiating the human body with microwaves and acquiring microwaves that pass through the heart. We first estimated the electric field strength transmitted through the heart using three receiving sensors to reduce the body movement effect. Then we decomposed the estimated transmitted electric field using stationary wavelet transform to eliminate significant distortion due to body movement. As a result, we achieved an estimation accuracy of heart-rate as high as 98% in a verification experiment with normal body movement.
连续监测心率有望实现对身体不适的早期检测。在这项研究中，我们提出了一种非接触式心率测量方法，可用于驾驶员心率监测等存在身体运动的环境中。该方法基于通过人体传输的随心脏舒张和收缩而变化的电场强度。与传统的皮肤表面位移检测不同，我们尝试通过向人体发射微波并获取穿过心脏的微波来捕捉人体内部结构的变化。我们首先使用三个接收传感器来估计穿过心脏的电场强度，以减少身体运动的影响。然后，我们使用平稳小波变换对估计的传输电场进行分解，以消除因身体运动而产生的显著失真。结果，在正常身体运动的验证实验中，我们实现了高达 98%的心率估计准确率。
