Measurement of breath noise from the surface of human thorax

Physical and mathematical models for the human thorax are proposed to estimate the efficiency of breath noise measurements by contact-type pickups. The models considered reflect the general peculiarities of the sound propagation channel from the source to the thorax wall. A mathematical model for the pickup (piezoaccelerometer) is developed that gives an adequate description of its electromechanical properties. An interaction between the pickup and the soft tissue of the thorax wall is investigated. Spatial-time distortions of the detected signal, which arise when the pickup interacts with the thorax wall, are estimated