Pasterkamp H, Fenton R, Tal A, Chernick V
Am Rev Respir Dis. 1985 Jan;131(1):61-4. doi: 10.1164/arrd.1985.131.S5.S61.
We have used fast Fourier transform and power spectra analysis to determine possible interference of cardiovascular sounds with the analysis of breath sounds in children. Ten normal children, 8 to 13 yr of age, were studied with sound transducer over midprecordium, right upper lobe, and right lower lobe along with simultaneously recorded ECG and air flow. Detection of R-waves facilitated sampling of sound segments at defined flow rates, with inclusion or exclusion of heart sounds. Measurements during breath-holding and without heart sounds served as baseline values. Heart sounds were only slightly attenuated over the right upper lobe. There was a considerable overlap in the power spectra of heart and breath sounds, mainly in frequencies below 100 Hz. Analysis of low-frequency components of normal breath sounds requires sampling during parts of the cardiac cycle that are free of cardiovascular sounds.
我们运用快速傅里叶变换和功率谱分析来确定儿童心音对呼吸音分析可能产生的干扰。对10名年龄在8至13岁的正常儿童进行了研究，使用声音传感器置于心前区中部、右上叶和右下叶，并同时记录心电图和气流。R波的检测有助于以规定流速对声音片段进行采样，包括或排除心音。屏气且无心脏声音时的测量值作为基线值。心音在右上叶仅略有衰减。心音和呼吸音的功率谱有相当大的重叠，主要在100赫兹以下的频率。对正常呼吸音低频成分的分析需要在心动周期中无心血管声音的部分进行采样。
