Stroke volume estimation from the new noninvasive cardiopulmonary stethoscope

This paper presents advanced signal processing techniques and associated results for measuring the stroke volume using cardiopulmonary stethoscope (CPS), a new noninvasive multiple vital signs sensor. The CPS is a novel sensor based on RF measurements on patient´s chest. It can noninvasively and accurately measure changes in lung water (CLW), heart rate (HR), and respiration rate (RR) as reported in previous studies. CPS cardiac signal was correlated with arterial blood pressure measurements for studying the feasibility of estimating this important parameter noninvasively. Stroke volume measurement was computed using two methods, namely mean arterial blood pressure and area under the curve. Validation results by comparison with arterial blood pressure waveform are presented.