Characteristics of the wave form of intrabronchial spark sounds on the chest wall and discontinuous adventitious lung sounds
Kudoh, S.; Kosaka, K.; Shibuya, A.; Aisaka, N.; Ono, I.; Shirai, S.
Nihon Kyobu Shikkan Gakkai Zasshi 18(1): 3-10
1980
ISSN/ISBN: 0301-1542 PMID: 7366036 Document Number: 164979
Impulsive sounds are widely used to investigate the acoustic transmission in the elastic bodies. Reverse dispersion because in the wave forms of discontinuous adventitious lung sounds, i.e., crackles, rales and crepitations. Impulsive sounds were generated by electrical spark discharge at the needle-gap inserted into the canine airway, and the wave forms on the chest wall were analyzed. The level of voltage on spark discharge was 7.5 kV, and the peak level of sound pressure was about 110 dB at 1 cm distance from the electrode in the free air field. The duration of the wave on the chest wall was 10 ms or more and it consisted of 3 different phases. The 1st phase, which was synchronic with the timing of discharge, was apparently caused by mixing of the electric wave on spark discharge. The 2nd phase was the maximum wave in terms of amplitude and duration. Reverse dispersion occurred as in discontinuous adventitious lung sounds. This phase was apparently basically surface wave and not a body wave directly derived from the source. Discontinuous adventitious lung sound apparently had characteristics of a surface wave. The physical meaning of the 3rd phase, which showed dumped oscillation in many cases, is uncertain.