Dalmasso F, Guarene M M, Spagnolo R, Benedetto G, Righini G
Bull Eur Physiopathol Respir. 1984 Mar-Apr;20(2):139-44.
A system for recording and processing lung crackles is described. These are detected by a microphone on the chest wall and recorded simultaneously with flow rate, tidal volume and oesophageal pressure on a four-channel tape recorder. The sound signal is subsequently digitized by an analog-to-digital converter and processed by a minicomputer, using the Time Series Language and the fast Fourier transform algorithm. A preliminary study on seven patients with cryptogenic fibrosing alveolitis (CFA) confirms that crackles typically occur at the end of inspiration; timing seems to be well related to inspired volume and esophageal pressure. Inspiratory crackles of CFA have a well-defined waveform: it consists of a starting component and a damped oscillation, which probably depends on the resonant frequency of the lung. The crackle energy content is mainly concentrated in the frequency range between 100 and 2 000 Hz, the spectrum shape being determined by the energy distribution between the two components of the waveform. This recording and processing system gives more complete information about crackles than auscultation does, allowing their quantification and reproducibility. It may be used to compare crackles in different diseases, and may be simplified and standardized for routine clinical use as an additional noninvasive diagnostic technique.
本文描述了一种用于记录和处理肺部啰音的系统。这些啰音通过胸壁上的麦克风进行检测，并与流速、潮气量和食管压力同时记录在四通道磁带录音机上。随后，声音信号由模数转换器数字化，并由小型计算机使用时间序列语言和快速傅里叶变换算法进行处理。对7例隐源性纤维性肺泡炎（CFA）患者的初步研究证实，啰音通常出现在吸气末；其时间似乎与吸入气量和食管压力密切相关。CFA的吸气性啰音具有明确的波形：它由一个起始成分和一个衰减振荡组成，这可能取决于肺的共振频率。啰音的能量含量主要集中在100至2000Hz的频率范围内，频谱形状由波形两个成分之间的能量分布决定。这种记录和处理系统比听诊能提供关于啰音更完整的信息，从而实现啰音的量化和可重复性。它可用于比较不同疾病中的啰音，并且可以简化和标准化，作为一种额外的无创诊断技术用于常规临床应用。
