A 24-GHz Doppler Sensor System for Cardiorespiratory Monitoring

In this paper, a 24-GHz Microwave band noninvasive sensor system for detecting and monitoring cardiorespiratory signals of patients is presented. The system consists of a sensor unit and a monitoring server. To demonstrate the proposal, a Doppler sensor unit operating at 24 GHz ISM band is fabricated. The fabricated radar unit shows below 6.2 % error for respiration rate when the distance between the patient and the radar system is below 1 m. The error increases to 7.3 % when the distance is increased to 2 m. To demonstrate the proposed medical sensor system, the life conditions of a subject is monitored. When an abnormality such as a stop breathing occurs, a warning signal is successfully generated automatically. In the case of an emergency, the health care workers can help the patients quicker.