Acoustic devices for breathing investigations

Abstract

The problem of spirometry control in medicine and medical engineering still remains urgent. The necessity of getting more and more information from spirometry investigations imposes more and more stringent requirements for spirometers, volumeters and bodypletizmographs, first of all, to the primary spiroflow transdusers. Practice shows that these requirements cannot be met by improving devices which use conventional spirometric principles. The new acoustic means for pulsating air-gas flow rate measurement has been created in Russia and is described in the paper. The main feature is special air-metric channel, supplied with ceramics electroacoustic transducers. The principle of its operation is based on the dependence of the acoustic vibrations arriving at the receiver velocity upon the air-gas flow rate. The device does not disturb the air dynamic structure of the flow, has no inertia or moving elements and unsurpassed sensitivity and precision.