Millimeter-Wave Frequency Modulated Continuous Wave Radar-Based Soft Fall Detection Using Pattern Contour-Confined Doppler-Time Maps

Fall accidents are one of the leading causes of non-natural death of older people. It is necessary to design and implement fall detection systems in older people’s homes. Among all indoor fall detection approaches, radar-based methods are considered one of the optimum solutions. In this paper, a millimetre-wave frequency modulated continuous wave (FMCW) radar-based fall detection method using pattern contour-confined Doppler-time (PCC-DT) maps is proposed. The soft fall motions, which can lead to missed detections, are studied and analyzed. When Doppler-time (DT) maps are used to interpret different motions, the redundant information and outliers can cause detection errors. The proposed PCC-DT map can diminish the superfluous information and remove outlier points to improve detection accuracy. The experimental results show that the proposed method can detect sudden and soft fall motions with high accuracy, sensitivity, and specificity.