ABSTRACT
This chapter examines how low-intensity, air-coupled, acoustic energy in the range from 0.2 to 5000 Hz can be used to noninvasively characterize the health of the respiratory system, as well as the middle-ear components of the auditory system through the measurement of acoustic impedance. The frequency characteristics of sound transmission through the thorax are also considered as candidate NI means of diagnosing obstructive lung diseases. The chapter also examines the history of respiratory acoustic impedance measurement systems (RAIMSs), and a RAIMS developed by the author and his graduate students. It illustrates the acoustic and electronic components of a general system for measuring the respiratory acoustic impedance. The chapter describes the two ways that have been devised to quantitatively measure the acoustic attenuation reflex. It expresses that how the transmission of audio-frequency acoustic energy through the chest and lungs can be used as an inexpensive, NI diagnostic tool to detect OLD and fluid in the lungs and pleural space.
