Development of remote radar based vital sign acquisition for emergency department patient triage

Introduction – To enable remote acquisition of patients' vital signs, ELTA Systems Ltd. developed a Radar remote vital signs acquisition system (TAMAR). The system identifies chest and neck respiratiory movements and pulse wave movements, enabling quantification of respiratory and pulse rates. The validation process of the TAMAR system is reported. Methods – A multicenter, prospective observational study was performed, enrolling low acuity patients who presented to 3 Emergency Departments. Patients provided consent and had their pulse and respiratory rates simultaneously measured by the TAMAR radar system and a traditional monitor (Mindray BeneVision N15). Vital signs were recorded continuously by both systems for 150 s, and later compared using Bland-Altman statistical analysis. Results – Between May and September 2021 we enrolled 315 patients. Measurements were calculated in 181/259 (70%) patients for Heart Rate (HR), and in 191/252 patients (76%) for Respiratory Rate (RR). For RR, the upper level of agreement (LOA) was 1.0, and the lower LOA was 1.6 respirations per minute. For HR, the upper level of agreement was 4.7, and the lower LOA was 3.5 beats per minute. All of these were well below the predetermined acceptable LOA of +/- 10 percent of the reference monitor rate. Discussion – The vital signs acquired by the TAMAR system, based on 90-second average measurements, are statistically adequate compared to traditional monitors, suggesting that TAMAR may replace traditional monitors for patients' triage.