A Self-Calibrating Radar Sensor System for Measuring Vital Signs

• Published in: IEEE transactions on biomedical circuits and systems Vol. 10; no. 2; pp. 352 - 363
• Main Authors: Ming-Chun Huang, Liu, Jason J., Wenyao Xu, Changzhan Gu, Changzhi Li, Sarrafzadeh, Majid
• Format: Journal Article
• Language: English
• Published: United States IEEE 01-04-2016; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Algorithms; Baseband; Biomedical measurement; Biosensing Techniques - instrumentation; Biosensing Techniques - methods; Calibration; Computer programs; Demodulation; Doppler radar; Equipment Design; Heart beat; Human performance; Humans; Medical; Microwaves; Monitoring; Monitoring, Physiologic - instrumentation; Monitoring, Physiologic - methods; Patients; Radar; Sensors; Software; vital sign measurement; Vital Signs - physiology
• ISSN: 1932-4545; 1940-9990
• DOI: 10.1109/TBCAS.2015.2411732

Vital signs (i.e., heartbeat and respiration) are crucial physiological signals that are useful in numerous medical applications. The process of measuring these signals should be simple, reliable, and comfortable for patients. In this paper, a noncontact self-calibrating vital signs monitoring system based on the Doppler radar is presented. The system hardware and software were designed with a four-tiered layer structure. To enable accurate vital signs measurement, baseband signals in the radar sensor were modeled and a framework for signal demodulation was proposed. Specifically, a signal model identification method was formulated into a quadratically constrained l1 minimization problem and solved using the upper bound and linear matrix inequality (LMI) relaxations. The performance of the proposed system was comprehensively evaluated using three experimental sets, and the results indicated that this system can be used to effectively measure human vital signs.