Impulse Radio UWB Radar-based Respiration Rate Estimation Method Under Clutter Environments

This paper presents an effective real-time IR-UWB radar-based respiration rate (RR) estimation method by exploring a simple clutter removal technique. The proposed method consists of radar matrix generation, clutter removal, bin selection, band-pass filter, Fourier magnitude computation, dominant spectral peak determination, and RR computation. The performance of the method is evaluated using the radar signals of 12 subjects collected at different distances (0.3, 0.5, 1, and 1.5 meters) from the radar locations and with their ground-truth RR values. The RR estimation method with clutter removal demonstrates accuracy improvement with reductions in mean absolute error (MAE) by 39.33%, standard deviation (SD) by 39.77%, root mean square error (RMSE) by 39.54%, and Bland-Altman Ratio (BAR) by 44.07%. Evaluation results further demonstrate that the proposed method improves the RR estimation accuracy with 46.02% for the estimation error (EE) range of 0-2 breaths per minute (BrPM). The method reduces estimation error for 65.22% of the segments with the clutter removal algorithm (from 670 to 233 segments for the EE range greater than 10 BrPM).