Non-invasive method and apparatus for determining lung tissue thermal properties and for extra vascular lung water measurement

Abstract

The subject matter discloses a noninvasive method and device for detection, measurement and monitoring of Pulmonary Interstitial fluid—Extravascular Lung Water —volumes in inpatient settings: Intensive Care Units, Emergency Rooms, Internal Hospital Departments, and daily monitoring of chronic patient in outpatient settings: outpatient departments, rehab centers and Home monitoring. The disclosed method is based on the analysis of lung tissue thermodynamic properties, and their deviation from normal value. The device measures the rate of temperature change of a lung tissue by measuring the exhaled gas temperature changing rate during cooling/heating of lung tissue. The cooling/heating of lung tissue may be achieved by prompt changing one of the inhaled gas parameters temperature, and/or humidity, and/or rate of breathing, and/or tidal volume, and/or type of gas and etc. The change is performed at the beginning of measurement, and is kept during entire measurement time.