Use of Non-Invasive Methods to Determine Stroke Volume

The current methods for estimating stroke volume rely on respiratory gas analysis, bioimpedance, echocardiography, and catheter-based techniques and are impractical for the battlefield environment. Research into the medical use of Ultra-WideBand (UWB) has shown it is capable of non-invasive collection of a variety of medically significant data and holds promise as a means of estimating cardiac stroke volume. In Phase I, we will demonstrate both in theory and practice that Ultra-WideBand Medical Radar (UWBMR) can detect conditions within the heart that will lead to a determination of changes in stroke volume. We propose to employ a two stage research project to meet the program requirements. First, we will conduct a theoretical analysis of the problem using computer-generated FDTD models of the heart and surrounding thoracic region. The volume of the cardiac chambers will be varied and the effects on the reflected radar energies will be evaluated to determine the UWB device's ability to detect changes in stroke volume. Second, we will validate the results from the computer model with tests on porcine animal models with an UWBMR array and synthetic aperture radar algorithms. Furthermore, we will demonstrate the potential to package the instrument into a hand-held device.