Computerized respiratory sounds can differentiate smokers and non-smokers

Cigarette smoking is often associated with the development of several respiratory diseases however, if diagnosed early, the changes in the lung tissue caused by smoking may be reversible. Computerised respiratory sounds have shown to be sensitive to detect changes within the lung tissue before any other measure, however it is unknown if it is able to detect changes in the lungs of healthy smokers. This study investigated the differences between computerised respiratory sounds of healthy smokers and non-smokers. Healthy smokers and non-smokers were recruited from a university campus. Respiratory sounds were recorded simultaneously at 6 chest locations (right and left anterior, lateral and posterior) using air-coupled electret microphones. Airflow (1.0–1.5 l/s) was recorded with a pneumotachograph. Breathing phases were detected using airflow signals and respiratory sounds with validated algorithms. Forty-four participants were enrolled: 18 smokers (mean age 26.2, SD = 7 years; mean FEV1 % predicted 104.7, SD = 9) and 26 non-smokers (mean age 25.9, SD = 3.7 years; mean FEV1 % predicted 96.8, SD = 20.2). Smokers presented significantly higher frequency at maximum sound intensity during inspiration [(M = 117, SD = 16.2 Hz vs. M = 106.4, SD = 21.6 Hz; t(43) = −2.62, p = 0.0081, d z = 0.55)], lower expiratory sound intensities (maximum intensity: [(M = 48.2, SD = 3.8 dB vs. M = 50.9, SD = 3.2 dB; t(43) = 2.68, p = 0.001, d z = −0.78)]; mean intensity: [(M = 31.2, SD = 3.6 dB vs. M = 33.7,SD = 3 dB; t(43) = 2.42, p = 0.001, d z = 0.75)] and higher number of inspiratory crackles (median [interquartile range] 2.2 [1.7–3.7] vs. 1.5 [1.2–2.2], p = 0.081, U = 110, r = −0.41) than non-smokers. Significant differences between computerised respiratory sounds of smokers and non-smokers have been found. Changes in respiratory sounds are often the earliest sign of disease. Thus, computerised respiratory sounds might be a promising measure to early detect smoking related respiratory diseases

Akciğer Solunum Seslerinin Spektral Öznitelikler ile Sınıflandırılması

Bu çalışmada güç spektrum yoğunluğu, mel frekans kepstral katsayıları (MFKK) ve algısal doğrusal öngörü (ADÖ) yöntemleri; çıtırtı, üfürüm ve normal akciğer solunum seslerini ayrıştırmak amacıyla kullanılan öznitelik çıkarıcılar olarak görevlendirilmiştir. Ham özniteliklerden sekiz alt öznitelik kümesi (enerji, entropi, en küçülten, en büyülten, ortalama, standart sapma, eğrilik ve basıklık) çıkarılarak k-en yakın komşu ve destek vektör makineleri sınıflandırıcılarına birini dışarıda bırak şeması kullanılarak beslenmiştir. Önerilen algısal doğrusal öngörü katsayıları yöntemi güç spektrum yoğunluğundan daha iyi performans sergilerken mel frekans kepstral katsayıları ile başa baş performans göstermiştir. ADÖ yönteminin üç gruplu sınıflandırma performansı var olan literatürle karşılaştırılmıştır. Çıtırtı, üfürüm ve normal sınıfları (% 94, % 95.5, % 95.5 sırasıyla) için en iyi sonuçlara ADÖ tarafından ulaşılmıştır. Diğer taraftan tüm sınıf doğruluklarının en iyi ortalama sonucuna % 91.3 ile MFKK tarafından ulaşılmıştır. MFKK ve ADÖ yöntemlerinin sınıflandırma doğruluğunun model derecesine oldukça bağlı olduğu gözlemlenmiştir

Visual classification of medical data using MLP mapping

In this work we discuss the design of a novel non-linear mapping method for visual classification based on multilayer perceptrons (MLP) and assigned class target values. In training the perceptron, one or more target output values for each class in a 2-dimensional space are used. In other words, class membership information is interpreted visually as closeness to target values in a 2D feature space. This mapping is obtained by training the multilayer perceptron (MLP) using class membership information, input data and judiciously chosen target values. Weights are estimated in such a way that each training feature of the corresponding class is forced to be mapped onto the corresponding 2-dimensional target value

ARTICLE IN PRESS Computers in Biology and Medicine ( ) –

www.elsevierhealth.com/locate/compbiomed Two-stage classi cation ofrespiratory sound pattern

An open access database for the evaluation of respiratory sound classification algorithms

Objective: Over the last few decades, there has been significant interest in the automatic analysis of respiratory sounds. However, currently there are no publicly available large databases with which new algorithms can be evaluated and compared. Further developments in the field are dependent on the creation of such databases. Approach: This paper describes a public respiratory sound database, which was compiled for an international competition, the first scientific challenge of the IFMBE’s International Conference on Biomedical and Health Informatics. The database includes 920 recordings acquired from 126 participants and two sets of annotations. One set contains 6898 annotated respiratory cycles, some including crackles, wheezes, or a combination of both, and some with no adventitious respiratory sounds. In the other set, precise locations of 10 775 events of crackles and wheezes were annotated. Main results: The best system that participated in the challenge achieved an average score of 52.5% with the respiratory cycle annotations and an average score of 91.2% with the event annotations. Significance: The creation and public release of this database will be useful to the research community and could bring attention to the respiratory sound classification problem.publishe