MICROWAVE METHODS OF MEASURING CHANGES IN LUNG WATER.

Two microwave methods for measuring changes in lung water content have been investigated. The first is based on measuring changes in the phase of an active microwave signal transmitted through the thorax, while the other is based on measuring the natural microwave radiation emitted by the body with a radiometer. The feasibility of using the active microwave method is investigated by making measurements on phantoms, on anesthetized dogs with induced pulmonary edema, and on isolated dog lungs. The obtained results clearly illustrated that the method is sensitive enough to measure small changes in lung water content.