SBIR-STTR Award

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.

Keywords:
Ultra-Wideband Medical Radar, Cardiopulmonary Function, Steroscopic Image Enhancement Using Synthetic Aperture Radar Processing Algoritms, Heart Disease/ Cardiovascular Health

LifeWave is completing work on the Phase I SBIR “Use of Non-Invasive Methods to Determine Stroke Volume”. Completed efforts to date include FDTD computer simulations of the UWB radar and human torso and algorithms for stroke volume measurement using cardiac phantom data. Results of these efforts show that it is theoretically possible to measure stroke volume with UWB radar. The objective of this Phase II proposal is to convert the Phase I effort into a miniature UWB radar module that connects to a commercially-available PDA and can accurately measure cardiac stroke volume. Based on the stroke volume and other derived metrics, the system will estimate levels of hemorrhagic shock and direct resuscitation in the hypovolemic patient. The system will also support storage and dissemination of biometric field data, enabling enhancements in triage algorithms and further improving casualty care. The technical approach involves collection of baseline cardiac data from porcine models and human subjects in a laboratory environment. This data will be used to refine the UWB radar circuitry and the signal processing algorithms. Enhancements will be validated in the lab using controlled exanguination in the porcine tests and lower body negative pressure in the human tests.

Keywords:
Ultra-Wideband, Stroke Volume, Health Monitoring, Emergency Medicine