Debreczeni L A, Korpas J, Salat D
Experimental Pathophysiological Research Unit, National Koranyi Institute for TBC and Pulmonology, Budapest, Hungary.
Bull Eur Physiopathol Respir. 1987;23 Suppl 10:57s-61s.
The voluntary cough sounds of healthy volunteers, patients with chronic rhinitis, chronic rhinitis with bronchial asthma and asthma were recorded with and without a nose clip. A gated series of signals of the first cough sound lasting 200 ms was analysed by a system with a 20 ms delay of the first signal. In the case of filtered cough sounds, low-cut digitally, the mean values of averaged spectra of the healthy volunteers showed a first peak around 350 Hz, similar to the expiratory spectra of respiratory sounds. Second and third harmonics were also identified. The mean values of averaged spectra from the patients with airway disease differed significantly in the range of low frequency components. The upper airways work as narrow-band acoustic filters determining the harmonic contents of speech as well as those of cough sounds. To minimize these effects for acoustic analytical purposes, the application of a nose clip is suggested to find the cough harmonics related to those of pulmonary sounds. The voluntary cough sounds contain diagnostic information, but to build up a quantitative, diagnostic, decision-making system, further investigations as well as standardization of recording and analysis are necessary.
在佩戴和不佩戴鼻夹的情况下，记录了健康志愿者、慢性鼻炎患者、伴有支气管哮喘的慢性鼻炎患者以及哮喘患者的自主咳嗽声音。使用对第一个信号有20毫秒延迟的系统，分析了持续200毫秒的第一个咳嗽声音的门控系列信号。对于经数字低通滤波的咳嗽声音，健康志愿者平均频谱的平均值在350赫兹左右出现第一个峰值，类似于呼吸音的呼气频谱。还识别出了第二和第三谐波。气道疾病患者平均频谱的平均值在低频成分范围内有显著差异。上呼吸道起到窄带声学滤波器的作用，决定了语音以及咳嗽声音的谐波成分。为了在声学分析中尽量减少这些影响，建议使用鼻夹来找出与肺音谐波相关的咳嗽谐波。自主咳嗽声音包含诊断信息，但要建立一个定量的诊断决策系统，还需要进一步的研究以及记录和分析的标准化。
