The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Alda Marques - One of the best experts on this subject based on the ideXlab platform.
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automatic classification of adventitious Respiratory Sounds a un solved problem
Sensors, 2020Co-Authors: Bruno Rocha, Alda Marques, Paulo Carvalho, Diogo Pessoa, Rui Pedro PaivaAbstract:(1) Background: Patients with Respiratory conditions typically exhibit adventitious Respiratory Sounds (ARS), such as wheezes and crackles. ARS events have variable duration. In this work we studied the influence of event duration on automatic ARS classification, namely, how the creation of the Other class (negative class) affected the classifiers' performance. (2) Methods: We conducted a set of experiments where we varied the durations of the other events on three tasks: crackle vs. wheeze vs. other (3 Class); crackle vs. other (2 Class Crackles); and wheeze vs. other (2 Class Wheezes). Four classifiers (linear discriminant analysis, support vector machines, boosted trees, and convolutional neural networks) were evaluated on those tasks using an open access Respiratory sound database. (3) Results: While on the 3 Class task with fixed durations, the best classifier achieved an accuracy of 96.9%, the same classifier reached an accuracy of 81.8% on the more realistic 3 Class task with variable durations. (4) Conclusion: These results demonstrate the importance of experimental design on the assessment of the performance of automatic ARS classification algorithms. Furthermore, they also indicate, unlike what is stated in the literature, that the automatic classification of ARS is not a solved problem, as the algorithms' performance decreases substantially under complex evaluation scenarios.
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enhancing our understanding of computerised adventitious Respiratory Sounds in different copd phases and healthy people
Respiratory Medicine, 2018Co-Authors: Ana Oliveira, Alda Marques, Joao M O S RodriguesAbstract:Abstract Background Timely diagnosis of acute exacerbations of COPD (AECOPD) is challenging as it depends on patients' reports. AECOPD are characterised by increased airway obstruction, mucus and air trapping, which results in changes in lung acoustics. Thus, adventitious Respiratory Sounds (ARS) may be useful to detect/monitor AECOPD. Objective To evaluate computerised ARS changes during AECOPD. Methods 25 non-hospitalised patients with AECOPD (16♂, 70 [62.5–77.0]yrs, FEV1 59 [31.5–73.0]%predicted) and 34 healthy volunteers (17♂, 63.5 [57.7–72.3]yrs, FEV1 103.0 [88.8–125.3]%predicted) were enrolled. ARS at anterior and posterior right and left chest were recorded at hospital presentation (T1), 15 days (T2) and 45 days (T3) after hospital presentation from patients with AECOPD and only once from healthy participants. A subsample of 9 patients (7♂; 66 [60.0–76.0]yrs; FEV1 62 [26.5–74.0]%predicted) was also included to study ARS pre-AECOPD (T0). Number of crackles and wheeze occupation rate (%Wh) were processed using validated algorithms. Results During AECOPD, patients presented more inspiratory crackles at T1 than T3 (p = 0.013) and more inspiratory %Wh at T1 than T2 (p = 0.006), at posterior chest. Patients with stable COPD presented more inspiratory crackles (p = 0.012), at posterior chest, and more expiratory %Wh, both at anterior (p 0.05). Conclusions Inspiratory crackles seem to persist until 15 days post exacerbation whilst inspiratory %Wh decreased after this period. ARS seem to be sensitive to monitor AECOPD. This information may allow advances in monitoring the recovery time of patients with AECOPD across all clinical and non-clinical settings.
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reliability validity and minimal detectable change of computerized Respiratory Sounds in patients with chronic obstructive pulmonary disease
Clinical Respiratory Journal, 2018Co-Authors: Alda Marques, Ana Oliveira, Joao M O S Rodrigues, Susan Martins LageAbstract:INTRODUCTION: Computerized Respiratory Sounds (CRS) are closely related to the movement of air within the tracheobronchial tree and are promising outcome measures in patients with chronic obstructive pulmonary disease (COPD). However, CRS measurement properties have been poorly tested. OBJECTIVE: The aim of this study was to assess the reliability, validity and the minimal detectable changes (MDC) of CRS in patients with stable COPD. METHODS: Fifty patients (36♂, 67.26 ± 9.31y, FEV1 49.52 ± 19.67%predicted) were enrolled. CRS were recorded simultaneously at seven anatomic locations (trachea; right and left anterior, lateral and posterior chest). The number of crackles, wheeze occupation rate, median frequency (F50) and maximum intensity (Imax) were processed using validated algorithms. Within-day and between-days reliability, criterion and construct validity, validity to predict exacerbations and MDC were established. RESULTS: CRS presented moderate-to-excellent within-day reliability (ICC1,3 ≥ 0.51; P 0.78). CRS correlated poorly with patient-reported outcomes (rs < 0.48; P < .05) and did not predict exacerbations. Inspiratory number of crackles at posterior right chest, inspiratory F50 at trachea and anterior left chest and expiratory Imax at anterior right chest were simultaneously reliable and valid, and their MDC were 2.41, 55.27, 29.55 and 3.98, respectively. CONCLUSION: CRS are reliable and valid. Their use, integrated with other clinical and patient-reported measures, may fill the gap of assessing small airways and contribute toward a patient's comprehensive evaluation.
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Normal Versus Adventitious Respiratory Sounds
Breath Sounds, 2018Co-Authors: Alda Marques, Ana OliveiraAbstract:Respiratory Sounds are composed by normal and adventitious Respiratory Sounds which comprise the Sounds heard over the trachea/mouth and chest wall. All Sounds can be described using frequency, intensity, and timbre. Frequency and intensity are perceived by human beings as pitch and loudness, respectively. Timbre allows the differentiation between two Sounds with the same frequency and intensity. For Respiratory Sounds, some additional information is often informative, such as the timing within the Respiratory cycle in which the sound occurs, the sound duration, and the influence of gravity/forced expiratory maneuvers on the sound. It is also important to know the origin and mechanisms of the Respiratory sound. Normal and adventitious Respiratory Sounds can be highly informative about a person’s Respiratory health as it is known that their characteristics change with gender, location where it is heard, body size, body position, and airflow, being particularly different between children and adults and in the presence of a Respiratory condition. This chapter provides a comprehensive understanding of the use of normal and adventitious Respiratory Sounds for identifying Respiratory conditions and their severity and monitoring Respiratory interventions.
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computerized Respiratory Sounds a comparison between patients with stable and exacerbated copd
Clinical Respiratory Journal, 2017Co-Authors: Ana Oliveira, Cristina Jácome, Alda MarquesAbstract:Introduction Diagnosis of acute exacerbations of chronic obstructive pulmonary disease (AECOPD) is often challenging as it relies on patients’ clinical presentation. Computerized Respiratory Sounds (CRS), namely crackles and wheezes, may have the potential to contribute for the objective diagnosis/monitoring of an AECOPD. Objectives: This study explored if CRS differ during stable and exacerbation periods in patients with COPD. Methods 13 patients with stable COPD and 14 with AECOPD were enrolled. CRS were recorded simultaneously at trachea, anterior, lateral and posterior chest locations using seven stethoscopes. Airflow (0.4–0.6l/s) was recorded with a pneumotachograph. Breathing phases were detected using airflow signals; crackles and wheezes with validated algorithms. Results At trachea, anterior and lateral chest, no significant differences were found between the two groups in the number of inspiratory/expiratory crackles or inspiratory wheeze occupation rate. At posterior chest, the number of crackles (median 2.97–3.17 vs. 0.83–1.2, P < 0.001) and wheeze occupation rate (median 3.28%–3.8% vs. 1.12%–1.77%, P = 0.014–0.016) during both inspiration and expiration were significantly higher in patients with AECOPD than in stable patients. During expiration, wheeze occupation rate was also significantly higher in patients with AECOPD at trachea (median 3.12% vs. 0.79%, P < 0.001) and anterior chest (median 3.55% vs. 1.28%, P < 0.001). Conclusion Crackles and wheezes are more frequent in patients with AECOPD than in stable patients, particularly at posterior chest. These findings suggest that these CRS can contribute to the objective diagnosis/monitoring of AECOPD, which is especially valuable considering that they can be obtained by integrating computerized techniques with pulmonary auscultation, a noninvasive method that is a component of patients’ physical examination.
Ana Oliveira - One of the best experts on this subject based on the ideXlab platform.
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reliability validity and minimal detectable change of computerized Respiratory Sounds in patients with chronic obstructive pulmonary disease
Clinical Respiratory Journal, 2018Co-Authors: Alda Marques, Ana Oliveira, Joao M O S Rodrigues, Susan Martins LageAbstract:INTRODUCTION: Computerized Respiratory Sounds (CRS) are closely related to the movement of air within the tracheobronchial tree and are promising outcome measures in patients with chronic obstructive pulmonary disease (COPD). However, CRS measurement properties have been poorly tested. OBJECTIVE: The aim of this study was to assess the reliability, validity and the minimal detectable changes (MDC) of CRS in patients with stable COPD. METHODS: Fifty patients (36♂, 67.26 ± 9.31y, FEV1 49.52 ± 19.67%predicted) were enrolled. CRS were recorded simultaneously at seven anatomic locations (trachea; right and left anterior, lateral and posterior chest). The number of crackles, wheeze occupation rate, median frequency (F50) and maximum intensity (Imax) were processed using validated algorithms. Within-day and between-days reliability, criterion and construct validity, validity to predict exacerbations and MDC were established. RESULTS: CRS presented moderate-to-excellent within-day reliability (ICC1,3 ≥ 0.51; P 0.78). CRS correlated poorly with patient-reported outcomes (rs < 0.48; P < .05) and did not predict exacerbations. Inspiratory number of crackles at posterior right chest, inspiratory F50 at trachea and anterior left chest and expiratory Imax at anterior right chest were simultaneously reliable and valid, and their MDC were 2.41, 55.27, 29.55 and 3.98, respectively. CONCLUSION: CRS are reliable and valid. Their use, integrated with other clinical and patient-reported measures, may fill the gap of assessing small airways and contribute toward a patient's comprehensive evaluation.
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enhancing our understanding of computerised adventitious Respiratory Sounds in different copd phases and healthy people
Respiratory Medicine, 2018Co-Authors: Ana Oliveira, Alda Marques, Joao M O S RodriguesAbstract:Abstract Background Timely diagnosis of acute exacerbations of COPD (AECOPD) is challenging as it depends on patients' reports. AECOPD are characterised by increased airway obstruction, mucus and air trapping, which results in changes in lung acoustics. Thus, adventitious Respiratory Sounds (ARS) may be useful to detect/monitor AECOPD. Objective To evaluate computerised ARS changes during AECOPD. Methods 25 non-hospitalised patients with AECOPD (16♂, 70 [62.5–77.0]yrs, FEV1 59 [31.5–73.0]%predicted) and 34 healthy volunteers (17♂, 63.5 [57.7–72.3]yrs, FEV1 103.0 [88.8–125.3]%predicted) were enrolled. ARS at anterior and posterior right and left chest were recorded at hospital presentation (T1), 15 days (T2) and 45 days (T3) after hospital presentation from patients with AECOPD and only once from healthy participants. A subsample of 9 patients (7♂; 66 [60.0–76.0]yrs; FEV1 62 [26.5–74.0]%predicted) was also included to study ARS pre-AECOPD (T0). Number of crackles and wheeze occupation rate (%Wh) were processed using validated algorithms. Results During AECOPD, patients presented more inspiratory crackles at T1 than T3 (p = 0.013) and more inspiratory %Wh at T1 than T2 (p = 0.006), at posterior chest. Patients with stable COPD presented more inspiratory crackles (p = 0.012), at posterior chest, and more expiratory %Wh, both at anterior (p 0.05). Conclusions Inspiratory crackles seem to persist until 15 days post exacerbation whilst inspiratory %Wh decreased after this period. ARS seem to be sensitive to monitor AECOPD. This information may allow advances in monitoring the recovery time of patients with AECOPD across all clinical and non-clinical settings.
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Normal Versus Adventitious Respiratory Sounds
Breath Sounds, 2018Co-Authors: Alda Marques, Ana OliveiraAbstract:Respiratory Sounds are composed by normal and adventitious Respiratory Sounds which comprise the Sounds heard over the trachea/mouth and chest wall. All Sounds can be described using frequency, intensity, and timbre. Frequency and intensity are perceived by human beings as pitch and loudness, respectively. Timbre allows the differentiation between two Sounds with the same frequency and intensity. For Respiratory Sounds, some additional information is often informative, such as the timing within the Respiratory cycle in which the sound occurs, the sound duration, and the influence of gravity/forced expiratory maneuvers on the sound. It is also important to know the origin and mechanisms of the Respiratory sound. Normal and adventitious Respiratory Sounds can be highly informative about a person’s Respiratory health as it is known that their characteristics change with gender, location where it is heard, body size, body position, and airflow, being particularly different between children and adults and in the presence of a Respiratory condition. This chapter provides a comprehensive understanding of the use of normal and adventitious Respiratory Sounds for identifying Respiratory conditions and their severity and monitoring Respiratory interventions.
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computerized Respiratory Sounds a comparison between patients with stable and exacerbated copd
Clinical Respiratory Journal, 2017Co-Authors: Ana Oliveira, Cristina Jácome, Alda MarquesAbstract:Introduction Diagnosis of acute exacerbations of chronic obstructive pulmonary disease (AECOPD) is often challenging as it relies on patients’ clinical presentation. Computerized Respiratory Sounds (CRS), namely crackles and wheezes, may have the potential to contribute for the objective diagnosis/monitoring of an AECOPD. Objectives: This study explored if CRS differ during stable and exacerbation periods in patients with COPD. Methods 13 patients with stable COPD and 14 with AECOPD were enrolled. CRS were recorded simultaneously at trachea, anterior, lateral and posterior chest locations using seven stethoscopes. Airflow (0.4–0.6l/s) was recorded with a pneumotachograph. Breathing phases were detected using airflow signals; crackles and wheezes with validated algorithms. Results At trachea, anterior and lateral chest, no significant differences were found between the two groups in the number of inspiratory/expiratory crackles or inspiratory wheeze occupation rate. At posterior chest, the number of crackles (median 2.97–3.17 vs. 0.83–1.2, P < 0.001) and wheeze occupation rate (median 3.28%–3.8% vs. 1.12%–1.77%, P = 0.014–0.016) during both inspiration and expiration were significantly higher in patients with AECOPD than in stable patients. During expiration, wheeze occupation rate was also significantly higher in patients with AECOPD at trachea (median 3.12% vs. 0.79%, P < 0.001) and anterior chest (median 3.55% vs. 1.28%, P < 0.001). Conclusion Crackles and wheezes are more frequent in patients with AECOPD than in stable patients, particularly at posterior chest. These findings suggest that these CRS can contribute to the objective diagnosis/monitoring of AECOPD, which is especially valuable considering that they can be obtained by integrating computerized techniques with pulmonary auscultation, a noninvasive method that is a component of patients’ physical examination.
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Computerised Respiratory Sounds can differentiate smokers and non-smokers.
Journal of clinical monitoring and computing, 2016Co-Authors: Ana Oliveira, Yasemin P. Kahya, Ipek Sen, Vera Afreixo, Alda MarquesAbstract: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.
Shinichiro Ohshimo - One of the best experts on this subject based on the ideXlab platform.
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A novel system that continuously visualizes and analyzes Respiratory Sounds to promptly evaluate upper airway abnormalities: a pilot study
Journal of Clinical Monitoring and Computing, 2021Co-Authors: Kazuya Kikutani, Shinichiro Ohshimo, Takuma Sadamori, Hiroshi Giga, Shingo Ohki, Tsubasa Nishida, Satoshi Yamaga, Nobuaki ShimeAbstract:Although Respiratory Sounds are useful indicators for evaluating abnormalities of the upper airway and lungs, the accuracy of their evaluation may be limited. The continuous evaluation and visualization of Respiratory Sounds has so far been impossible. To resolve these problems, we developed a novel continuous visualization system for assessing Respiratory Sounds. Our novel system was used to evaluate Respiratory abnormalities in two patients. The results were not known until later. The first patient was a 23-year-old man with chronic granulomatous disease and persistent anorexia. During his hospital stay, he exhibited a consciousness disorder, bradypnea, and hypercapnia requiring tracheal intubation. After the administration of muscle relaxant, he suddenly developed acute airway stenosis. Because we could not intubate and ventilate, we performed cricothyroidotomy. Subsequent review of our novel system revealed mild stridor before the onset of acute airway stenosis, which had not been recognized clinically. The second patient was a 74-year-old woman who had been intubated several days earlier for tracheal burn injury, and was extubated after alleviation of her laryngeal edema. After extubation, she gradually developed inspiratory stridor. We re-intubated her after diagnosing post-extubation laryngeal edema. Subsequent review of our novel system revealed serially increased stridor after the extubation, at an earlier time than was recognized by healthcare providers. This unique continuous monitoring and visualization system for Respiratory Sounds could be an objective tool for improving patient safety regarding airway complications.
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Innovation in Analysis of Respiratory Sounds
Annals of internal medicine, 2016Co-Authors: Shinichiro Ohshimo, Takuma Sadamori, Koichi TanigawaAbstract:It is difficult to describe the Sounds of breathing, especially when different types of sound are present at the same time. The authors propose the use of an electronic stethoscope with innovative ...
Nobuaki Shime - One of the best experts on this subject based on the ideXlab platform.
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A novel system that continuously visualizes and analyzes Respiratory Sounds to promptly evaluate upper airway abnormalities: a pilot study
Journal of Clinical Monitoring and Computing, 2021Co-Authors: Kazuya Kikutani, Shinichiro Ohshimo, Takuma Sadamori, Hiroshi Giga, Shingo Ohki, Tsubasa Nishida, Satoshi Yamaga, Nobuaki ShimeAbstract:Although Respiratory Sounds are useful indicators for evaluating abnormalities of the upper airway and lungs, the accuracy of their evaluation may be limited. The continuous evaluation and visualization of Respiratory Sounds has so far been impossible. To resolve these problems, we developed a novel continuous visualization system for assessing Respiratory Sounds. Our novel system was used to evaluate Respiratory abnormalities in two patients. The results were not known until later. The first patient was a 23-year-old man with chronic granulomatous disease and persistent anorexia. During his hospital stay, he exhibited a consciousness disorder, bradypnea, and hypercapnia requiring tracheal intubation. After the administration of muscle relaxant, he suddenly developed acute airway stenosis. Because we could not intubate and ventilate, we performed cricothyroidotomy. Subsequent review of our novel system revealed mild stridor before the onset of acute airway stenosis, which had not been recognized clinically. The second patient was a 74-year-old woman who had been intubated several days earlier for tracheal burn injury, and was extubated after alleviation of her laryngeal edema. After extubation, she gradually developed inspiratory stridor. We re-intubated her after diagnosing post-extubation laryngeal edema. Subsequent review of our novel system revealed serially increased stridor after the extubation, at an earlier time than was recognized by healthcare providers. This unique continuous monitoring and visualization system for Respiratory Sounds could be an objective tool for improving patient safety regarding airway complications.
Takuma Sadamori - One of the best experts on this subject based on the ideXlab platform.
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A novel system that continuously visualizes and analyzes Respiratory Sounds to promptly evaluate upper airway abnormalities: a pilot study
Journal of Clinical Monitoring and Computing, 2021Co-Authors: Kazuya Kikutani, Shinichiro Ohshimo, Takuma Sadamori, Hiroshi Giga, Shingo Ohki, Tsubasa Nishida, Satoshi Yamaga, Nobuaki ShimeAbstract:Although Respiratory Sounds are useful indicators for evaluating abnormalities of the upper airway and lungs, the accuracy of their evaluation may be limited. The continuous evaluation and visualization of Respiratory Sounds has so far been impossible. To resolve these problems, we developed a novel continuous visualization system for assessing Respiratory Sounds. Our novel system was used to evaluate Respiratory abnormalities in two patients. The results were not known until later. The first patient was a 23-year-old man with chronic granulomatous disease and persistent anorexia. During his hospital stay, he exhibited a consciousness disorder, bradypnea, and hypercapnia requiring tracheal intubation. After the administration of muscle relaxant, he suddenly developed acute airway stenosis. Because we could not intubate and ventilate, we performed cricothyroidotomy. Subsequent review of our novel system revealed mild stridor before the onset of acute airway stenosis, which had not been recognized clinically. The second patient was a 74-year-old woman who had been intubated several days earlier for tracheal burn injury, and was extubated after alleviation of her laryngeal edema. After extubation, she gradually developed inspiratory stridor. We re-intubated her after diagnosing post-extubation laryngeal edema. Subsequent review of our novel system revealed serially increased stridor after the extubation, at an earlier time than was recognized by healthcare providers. This unique continuous monitoring and visualization system for Respiratory Sounds could be an objective tool for improving patient safety regarding airway complications.
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Innovation in Analysis of Respiratory Sounds
Annals of internal medicine, 2016Co-Authors: Shinichiro Ohshimo, Takuma Sadamori, Koichi TanigawaAbstract:It is difficult to describe the Sounds of breathing, especially when different types of sound are present at the same time. The authors propose the use of an electronic stethoscope with innovative ...