Non-Contact Multi-Subject Human Gait Analysis Using A State-Space Method With Enhanced 1-D Block Representation

A stepped-frequency continuous-wave (SFCW) radar system with adequate pulse repetition frequency (PRF) is developed to track relatively fast motions from various parts of the human body, separately. Robust signal processing technique is utilized, where a 1-D block processing technique, based on state-space method (SSM) is developed in two dimensions to form an enhanced Hankel matrix to track human motions from two-dimensional (2-D) data collected using the developed SFCW radar system in single- or multi-subject motion scenarios. Experimental datasets are used to track body parts' motions and velocities with high accuracy. The significant improvement, besides de-noising the data, is due to the fact that applying the 1-D block processing technique to 2-D dataset matrix accounts for the correlation between motion's estimates from consecutive frames. Results agree well with our reference, the human Boulic model.

I. Introduction

Human gait investigations continue to attract many scientists and practitioners in various fields such as sport medicine, geriatric medicine, bio-mechanic and bio-medical engineering. These investigations include segmentation of human body parts for athletic performance evaluation [1], health issue diagnosis [2]–[4], automatic monitoring of human activities in security-sensitive zones [5], elderly health care monitoring [6], man–machine user interface design [7], and smart video conferencing [8]. To further understand any motion abnormalities, we need first to thoroughly track and understand the normal motion of human limb joints.