Accurate Heart Rate and Respiration Rate Detection Based on a Higher-Order Harmonics Peak Selection Method Using Radar Non-Contact Sensors

Abstract

Vital signs such as heart rate and respiration rate are among the most important physiological signals for health monitoring and medical applications. Impulse radio (IR) ultra-wideband (UWB) radar becomes one of the essential sensors in non-contact vital signs detection. The heart pulse wave is easily corrupted by noise and respiration activity since the heartbeat signal has less power compared with the breathing signal and its harmonics. In this paper, a signal processing technique for a UWB radar system was developed to detect the heart rate and respiration rate. There are four main stages of signal processing: (1) clutter removal to reduce the static random noise from the environment; (2) independent component analysis (ICA) to do dimension reduction and remove noise; (3) using low-pass and high-pass filters to eliminate the out of band noise; (4) modified covariance method for spectrum estimation. Furthermore, higher harmonics of heart rate were used to estimate heart rate and minimize respiration interference. The experiments in this article contain different scenarios including bed angle, body position, as well as interference from the visitor near the bed and away from the bed. The results were compared with the ECG sensor and respiration belt. The average mean absolute error (MAE) of heart rate results is 1.32 for the proposed algorithm.

Evaluation Protocol for Analogue Intelligent Medical Radars: Towards a Systematic Approach Based on Theory and a State of the Art

“…In this section, we analyse more than 50 papers on medical radar experiments in order to extract from them interesting elements about their protocols [ 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 , 71 , 72 , 73 , 74 , 75 ...…”

Classification of Respiratory States Using Spectrogram with Convolutional Neural Network

“…When using UWB radar sensors for respiration measurement, patients (or persons who need measurements to be taken) do not have inconveniences in attaching the device. The UWB radar sensor provides a high signal-to-noise ratio and accuracy of measurement [38]. If the reflected signal is not pre-processed, various types of filters such as the Kalman filter, bandpass filter, median filter, etc., are employed to enhance the quality of the signals.…”

Non-Contact VITAL Signs Monitoring of a Patient Lying on Surgical Bed Using Beamforming FMCW Radar

“…Therefore, in surgery, the vital signs should be monitored without contact. To monitor the vital signs without contact, a radar sensor has been considered in much research [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 ]. However, when the surgeon performs surgery for the patient lying on the surgical bed, the surgeon’s movements reduce the vital sign accuracies monitored by the radar.…”

“…The CW Doppler radar system is very simple and relatively cheap; however, it cannot distinguish between two or more objects at different ranges simultaneously. Some recent studies have adopted the ultra-wide-band (UWB) [ 5 , 6 , 7 , 8 , 9 ] or FMCW radar [ 15 , 32 , 33 , 34 , 35 , 36 , 37 ], which can distinguish several objects at different ranges.…”