Human gait involves a complex mechanism of muscular skeletal coordinated operation,which is specific and can be used as the basis of identity recognitions and clinical disease diagnoses.Human gaits have wide application value in the field of disaster rescue,battlefield ambulance,counter-terrorism,security,and medical and healthcare.The traditional contact-free gait detection technology mainly depends on optical images or ultrasound,which is susceptible to light,low visibility,obstacles,etc.In recent years,with the rapidly development of bio-radar technology,the bio-radar based contact-free human gait signal detection technology has shown more advantages.It can not be affected by light,can penetrate clothing,camouflage or even walls,and can operate in all-weathe,including low visibility weather conditions such as smog,smoke and fog.In this paper,the technical principles and methods of bio-radar based contact-free human gait detection technologies were discussed,the research status was summarized,and the development trendency was prospected.

Based on the analysis of the existing problems and implementation dilemmas in family doctor contracting and first-return-visits faced by primary medical institutions in China, the authors propose countermeasures to provide reference for managers of primary health care institutions.