Noncontact Wrist Pulse Waveform Detection Using 24-GHz Continuous-Wave Radar Sensor for Blood Pressure Estimation

In this paper, a compact 24-GHz continuous-wave radar sensor is developed to detect the wrist pulse waveform for blood pressure (BP) estimation. The systolic and diastolic BPs can be calculated by the reflective pulse transit time (R-PTT) using the BP computation algorithm. Instead of using conventional PTT, the R-PTT is re-defined as the propagation time interval between the forward and reflected pressure waves observed at the radial artery area in this paper. It can be then extracted from the wrist pulse waveform, which is remotely measured by the radar sensor. The BPs of a 23-year-old female have been continuously monitored for 8 days and compared with the commercial cuff-based BP monitor. The measured mean difference (MD) and standard deviation (SD) of the proposed BP radar sensor are 0.55±5.45 mmHg (MD±SD) and -2.26±3.93 mmHg (MD±SD) for systolic and diastolic BPs, respectively.