215 research outputs found

    Analysis of Respiratory Sounds: State of the Art

    Get PDF
    Objective This paper describes state of the art, scientific publications and ongoing research related to the methods of analysis of respiratory sounds. Methods and material Review of the current medical and technological literature using Pubmed and personal experience. Results The study includes a description of the various techniques that are being used to collect auscultation sounds, a physical description of known pathologic sounds for which automatic detection tools were developed. Modern tools are based on artificial intelligence and on technics such as artificial neural networks, fuzzy systems, and genetic algorithms… Conclusion The next step will consist in finding new markers so as to increase the efficiency of decision aid algorithms and tools

    Performance evaluation of the Hilbert–Huang transform for respiratory sound analysis and its application to continuous adventitious sound characterization

    Get PDF
    © 2016. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/The use of the Hilbert–Huang transform in the analysis of biomedical signals has increased during the past few years, but its use for respiratory sound (RS) analysis is still limited. The technique includes two steps: empirical mode decomposition (EMD) and instantaneous frequency (IF) estimation. Although the mode mixing (MM) problem of EMD has been widely discussed, this technique continues to be used in many RS analysis algorithms. In this study, we analyzed the MM effect in RS signals recorded from 30 asthmatic patients, and studied the performance of ensemble EMD (EEMD) and noise-assisted multivariate EMD (NA-MEMD) as means for preventing this effect. We propose quantitative parameters for measuring the size, reduction of MM, and residual noise level of each method. These parameters showed that EEMD is a good solution for MM, thus outperforming NA-MEMD. After testing different IF estimators, we propose Kay¿s method to calculate an EEMD-Kay-based Hilbert spectrum that offers high energy concentrations and high time and high frequency resolutions. We also propose an algorithm for the automatic characterization of continuous adventitious sounds (CAS). The tests performed showed that the proposed EEMD-Kay-based Hilbert spectrum makes it possible to determine CAS more precisely than other conventional time-frequency techniques.Postprint (author's final draft

    Distinguishing Between Asthma and Pneumonia Through Automated Lung Sound Analysis

    Get PDF
    This project attempts to distinguish between two pulmonary disorders, asthma and pneumonia, using automated analysis of lung sounds. Such an approach minimizes the subjectivity of diagnosis inherent to current practices by physicians. Breath sounds are recorded by a physiological microphone and hardware acquisition system, and then analyzed in software using a two stage algorithm. The first stage detects abnormal lung sounds and second stage makes a diagnosis. A clinical trial was conducted at a pediatric clinic to validate the system

    Application of clustering techniques for lung sounds to improve interpretability and detection of crackles

    Get PDF
    Due to the subjectivity involved currently in pulmonary auscultation process and its diagnostic to evaluate the condition of respiratory airways, this work pretends to evaluate the performance of clustering algorithms such as k-means and DBSCAN to perform a computational analysis of lung sounds aiming to visualize a representation of such sounds that highlights the presence of crackles and the energy associated with them. In order to achieve that goal, Wavelet analysis techniques were used in contrast to traditional frequency analysis given the similarity between the typical waveform for a crackle and the wavelet sym4. Once the lung sound signal with isolated crackles is obtained, the clustering process groups crackles in regions of high density and provides visualization that might be useful for the diagnostic made by an expert. Evaluation suggests that k-means groups crackle more effective than DBSCAN in terms of generated clusters.Debido a la subjetividad que involucra actualmente el proceso de auscultación pulmonar y su diagnóstico para evaluar la condición de las vías respiratorias de un paciente, este trabajo busca evaluar el desempeño de los algoritmos de clustering: k-means y DBSCAN para efectuar un análisis computacional de sonidos pulmonares con el objetivo de visualizar una representación de dichos sonidos que exalte la presencia de estertores y la energía contenida en ellos. Para este fin, se emplearon técnicas de descomposición y análisis Wavelet a diferencia del tradicional análisis en frecuencia dada la similitud entre la forma de onda de un estertor típico y la wavelet sym4. Obtenida la señal de sonido pulmonar con estertores aislados, el proceso de clustering agrupa estertores en regiones de alta presencia y ofrece una visualización que puede ser de utilidad para el diagnóstico hecho por un experto. La evaluación hecha sugiere que k-means agrupa conjuntos de estertores de forma más efectiva que DBSCAN en términos de clusters generados

    Aplicación de Técnicas de Clustering en Sonidos Adventicios para Mejorar la Interpretabilidad y Detección de Estertores

    Get PDF
    Due to the subjectivity involved currently in pulmonary auscultation process and its diagnostic to evaluate the condition of respiratory airways, this work pretends to evaluate the performance of clustering algorithms such as k-means and DBSCAN to perform a computational analysis of lung sounds aiming to visualize a representation of such sounds that highlights the presence of crackles and the energy associated with them. In order to achieve that goal, Wavelet analysis techniques were used in contrast to traditional frequency analysis given the similarity between the typical waveform for a crackle and the wavelet sym4. Once the lung sound signal with isolated crackles is obtained, the clustering process groups crackles in regions of high density and provides visualization that might be useful for the diagnostic made by an expert. Evaluation suggests that k-means groups crackle more effective than DBSCAN in terms of generated clusters. Debido a la subjetividad que involucra actualmente el proceso de auscultación pulmonar y su diagnóstico para evaluar la condición de las vías respiratorias de un paciente, este trabajo busca evaluar el desempeño de los algoritmos de clustering: k-means y DBSCAN para efectuar un análisis computacional de sonidos pulmonares con el objetivo de visualizar una representación de dichos sonidos que exalte la presencia de estertores y la energía contenida en ellos. Para este fin, se emplearon técnicas de descomposición y análisis Wavelet a diferencia del tradicional análisis en frecuencia dada la similitud entre la forma de onda de un estertor típico y la wavelet sym4. Obtenida la señal de sonido pulmonar con estertores aislados, el proceso de clustering agrupa estertores en regiones de alta presencia y ofrece una visualización que puede ser de utilidad para el diagnóstico hecho por un experto. La evaluación hecha sugiere que k-means agrupa conjuntos de estertores de forma más efectiva que DBSCAN en términos de clusters generados
    corecore