Data reduction for cough studies using distribution of audio frequency content.
Data reduction for cough studies using distribution of audio frequency content.
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DOI：
10.1186/1745-9974-8-12
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发表时间：
2012-12-12
期刊：
影响因子：
--
通讯作者：
Smith JA
中科院分区：
文献类型：
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作者：
Barton A;Gaydecki P;Holt K;Smith JA
最近的研究表明，客观地量化录音中的咳嗽提供了一种新的手段来了解咳嗽和评估治疗。目前，手动咳嗽计数是量化咳嗽的最准确方法。然而，手动计数咳嗽记录的需求是巨大的，这表明需要在计数之前减少记录长度，同时保留其中的咳嗽。本研究测试了为此目的开发的算法的性能。招募了20名受试者（5名健康吸烟者和非吸烟者，5名慢性咳嗽，5名慢性阻塞性肺病和5名哮喘），配备了动态记录系统并记录24小时。将产生的记录分成15分钟的片段并计数。使用音频信号的中值频率和功率去除每个片段中的非活动音频时段，并对所产生的文件重新计数。所得节段长度中位数为13.9 s（IQR 56.4 s），24小时记录长度中位数为62.4 min（IQR 100.4）。错误地删除了中位数0.0次咳嗽/h（IQR 0.0-0.2），所得咳嗽计数的变异性与手动咳嗽计数之间的变异性相当。在哮喘患者中观察到最大的误差，但仍然只有1.0%的咳嗽/h被遗漏。这些数据表明，使用中值音频频率测量信号活动的系统可以显著减少记录长度，而不会显著损害其中包含的咳嗽。
Recent studies suggest that objectively quantifying coughing in audio recordings offers a novel means to understand coughing and assess treatments. Currently, manual cough counting is the most accurate method for quantifying coughing. However, the demand of manually counting cough records is substantial, demonstrating a need to reduce record lengths prior to counting whilst preserving the coughs within them. This study tested the performance of an algorithm developed for this purpose. 20 subjects were recruited (5 healthy smokers and non-smokers, 5 chronic cough, 5 chronic obstructive pulmonary disease and 5 asthma), fitted with an ambulatory recording system and recorded for 24 hours. The recordings produced were divided into 15 min segments and counted. Periods of inactive audio in each segment were removed using the median frequency and power of the audio signal and the resulting files re-counted. The median resultant segment length was 13.9 s (IQR 56.4 s) and median 24 hr recording length 62.4 min (IQR 100.4). A median of 0.0 coughs/h (IQR 0.0-0.2) were erroneously removed and the variability in the resultant cough counts was comparable to that between manual cough counts. The largest error was seen in asthmatic patients, but still only 1.0% coughs/h were missed. These data show that a system which measures signal activity using the median audio frequency can substantially reduce record lengths without significantly compromising the coughs contained within them.