【摘要】 本文应用快速付氏换对正常呼吸音进行了谱分析,应用相干函数研究了气管音与肺胞呼吸音的相干性,以及胸部不同部位肺胞呼吸音之间的相干性。结果表明,肺胞呼吸音功率谱值频率增加里指数衰减,其能量主要集中在300Hz以内,气管音功率谱分布在较宽的频带内.在100～500 Hz频率范围内,气管音与肺胞呼吸音之间有较大的相干系数,在500Hz以上的频段内,两者之间相干系数几乎为零。在80～300HZz带内,胸部两个不同部位的肺胞呼吸音的相干系数较小。研究结果表明,气管音与肺胞呼吸音之间有较大的相关性,这两种音足气流与肺、气管等相互作用下产生的白噪声音源在不同声道上的传播至体表的生理声信号。肺胞呼吸音产生与传播与肺局部功能有关,表明了肺胞呼吸音产生传播的局部特性。更多还原

【Abstract】 In this paper, the spectra ofnormal breath sounds were analyzedby using FFT method. The coher-ence between tracheal breath soundsand vesicular breath sounds, variousvesicular breaths at different positionof chest were investigated. The spec-tra showed that: the power spec-tra of vesicular breath sounds wereexponentially decreased with the in-crease of frequency, and the energywas concentrated mainly below 300Hz.The power spectra of tracheal breathsounds were distributed over awider frequency-band. The coherencecoefficiency value between trachealbreath sounds and vesicular breathsounds was greater in range of 100- 500Hz,and it was almost equal to0 above 500Hz, In the range of 80-300Hz, the coherence coefficiencyof vesicular breath sounds at twodifferent positions on the thorax wellwas smaller. The results indicatedthat there were significant coher-ence between trachea breath soundsand vesicular breath sounds. Thesetwo sounds were physiological soundsignal, which were white-noisesources under the co-action of air-flow and lung tissues transmitted tobody surface through differentsounds ways. Bronchus within a cer-tain range of lung affected the pro-duction and transmission of the twosounds. The production and trans-mission of vesicular breath soundswere related to the local function oflung.更多还原