School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798, Singapore.
SCALE @ NTU Corp Lab, Nanyang Technological University, Singapore 639798, Singapore.
Sensors (Basel). 2022 Apr 19;22(9):3106. doi: 10.3390/s22093106.
A non-contact, non-invasive monitoring system to measure and estimate the heart and breathing rate of humans using a frequency-modulated continuous wave (FMCW) mm-wave radar at 77 GHz is presented. A novel diagnostic system is proposed which extracts heartbeat phase signals from the FMCW radar (reconstructed using Fourier series analysis) to test a three-layer artificial neural network model to predict the presence of arrhythmia in individuals. The effect of person orientation, distance of measurement and movement was analyzed with respect to a reference device based on statistical measures that include number of outliers, mean, mean squared error (MSE), mean absolute error (MAE), median absolute error (medAE), skewness, standard deviation (SD) and R-squared values. The individual oriented in front of the radar outperformed almost all other orientations for most distances with an expected d = 90 cm and d = 120 cm. Furthermore, it was found that the heart rate that was measured while walking and the breathing rate which was measured for a motionless individual generated results with the lowest SD and MSE. An artificial neural network (ANN) was trained using the MIT-BIH database with a training accuracy of 93.9 % and an R value = 0.876. The diagnostic tool was tested on 15 subjects and achieved a mean test accuracy of 75%.
提出了一种使用 77GHz 调频连续波(FMCW)毫米波雷达测量和估计人类心率和呼吸率的非接触式、非侵入式监测系统。提出了一种新的诊断系统,该系统从 FMCW 雷达(使用傅里叶级数分析重建)中提取心跳相位信号,以测试三层人工神经网络模型,预测个体是否存在心律失常。使用包括异常值数量、均值、均方误差(MSE)、平均绝对误差(MAE)、中位数绝对误差(medAE)、偏度、标准差(SD)和 R 平方值在内的统计度量标准,分析了人员方向、测量距离和运动的影响。与基于统计数据的参考设备相比,雷达前定向的个体在大多数距离下的表现优于几乎所有其他定向,预期距离为 90cm 和 120cm。此外,还发现,在行走时测量的心率和对静止个体测量的呼吸率生成的结果具有最低的 SD 和 MSE。使用 MIT-BIH 数据库训练了一个人工神经网络(ANN),训练精度为 93.9%,R 值=0.876。该诊断工具在 15 名受试者上进行了测试,平均测试准确率为 75%。