連続性ラ音の音響学的性状および伝播特性に関する検討 ： 気管支狭窄による連続性ラ音と気管支喘息患者ラ音の対比検討

Abstract

The author studied the acoustic features of continuous adventitious lung sounds in asthmatic patients, and analyzed the characteristics of transmission by comparing the continuous sounds in asthmatic patients with those due to bronchial stenosis. The results were as follows ; 1) Continuous adventitious lung sounds in patients with bronchial stenosis confirmed by bronchoscopy were well transmitted to the neck over the trachea. Therefore, it was demonstrated that continuous adventitious lung sounds generated in the lung were able to be transmitted to the tracheal region. 2) continnous adventitious lung sounds in asthmatic patients were divided into monophonic tones and polyphonic tones, according to sound spectrographic findings. From the results of coherence analysis, the monophonic tones were considered to be generated in the right or left lung and were well transmitted to the neck over the trachea. Therefore, it was confirmed that the tracheal region is a very important location for auscultating and monitoring asthmatic patients. 3) From the results of cross-correlation analysis, it was suggested that the continuous adventitious lung sounds due to bronchial stenosis could be differentiated from those in asthmatic patients.