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Lauwers E, Stas T, McLane I, Snoeckx A, Van Hoorenbeeck K, De Backer W, Ides K, Steckel J, Verhulst S. Exploring the link between a novel approach for computer aided lung sound analysis and imaging biomarkers: a cross-sectional study. Respir Res 2024; 25:177. [PMID: 38658980 PMCID: PMC11044477 DOI: 10.1186/s12931-024-02810-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2023] [Accepted: 04/09/2024] [Indexed: 04/26/2024] Open
Abstract
BACKGROUND Computer Aided Lung Sound Analysis (CALSA) aims to overcome limitations associated with standard lung auscultation by removing the subjective component and allowing quantification of sound characteristics. In this proof-of-concept study, a novel automated approach was evaluated in real patient data by comparing lung sound characteristics to structural and functional imaging biomarkers. METHODS Patients with cystic fibrosis (CF) aged > 5y were recruited in a prospective cross-sectional study. CT scans were analyzed by the CF-CT scoring method and Functional Respiratory Imaging (FRI). A digital stethoscope was used to record lung sounds at six chest locations. Following sound characteristics were determined: expiration-to-inspiration (E/I) signal power ratios within different frequency ranges, number of crackles per respiratory phase and wheeze parameters. Linear mixed-effects models were computed to relate CALSA parameters to imaging biomarkers on a lobar level. RESULTS 222 recordings from 25 CF patients were included. Significant associations were found between E/I ratios and structural abnormalities, of which the ratio between 200 and 400 Hz appeared to be most clinically relevant due to its relation with bronchiectasis, mucus plugging, bronchial wall thickening and air trapping on CT. The number of crackles was also associated with multiple structural abnormalities as well as regional airway resistance determined by FRI. Wheeze parameters were not considered in the statistical analysis, since wheezing was detected in only one recording. CONCLUSIONS The present study is the first to investigate associations between auscultatory findings and imaging biomarkers, which are considered the gold standard to evaluate the respiratory system. Despite the exploratory nature of this study, the results showed various meaningful associations that highlight the potential value of automated CALSA as a novel non-invasive outcome measure in future research and clinical practice.
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Affiliation(s)
- Eline Lauwers
- Laboratory of Experimental Medicine and Pediatrics and member of Infla-Med Research Consortium of Excellence, University of Antwerp, Wilrijk, Belgium.
- Fluidda NV, Kontich, Belgium.
| | - Toon Stas
- CoSys-Lab Research Group, University of Antwerp and Flanders Make Strategic Research Center, Wilrijk, Lommel, Belgium
| | - Ian McLane
- Sonavi Labs, Baltimore, MD, USA
- Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Annemiek Snoeckx
- Department of Radiology, Antwerp University Hospital, Edegem, Belgium
- Faculty of Medicine and Health Sciences, University of Antwerp, Wilrijk, Belgium
| | - Kim Van Hoorenbeeck
- Laboratory of Experimental Medicine and Pediatrics and member of Infla-Med Research Consortium of Excellence, University of Antwerp, Wilrijk, Belgium
- Department of Pediatrics, Antwerp University Hospital, Edegem, Belgium
| | - Wilfried De Backer
- Faculty of Medicine and Health Sciences, University of Antwerp, Wilrijk, Belgium
- Fluidda NV, Kontich, Belgium
- MedImprove BV, Kontich, Belgium
| | - Kris Ides
- Laboratory of Experimental Medicine and Pediatrics and member of Infla-Med Research Consortium of Excellence, University of Antwerp, Wilrijk, Belgium
- CoSys-Lab Research Group, University of Antwerp and Flanders Make Strategic Research Center, Wilrijk, Lommel, Belgium
- Department of Pediatrics, Antwerp University Hospital, Edegem, Belgium
- MedImprove BV, Kontich, Belgium
| | - Jan Steckel
- CoSys-Lab Research Group, University of Antwerp and Flanders Make Strategic Research Center, Wilrijk, Lommel, Belgium
| | - Stijn Verhulst
- Laboratory of Experimental Medicine and Pediatrics and member of Infla-Med Research Consortium of Excellence, University of Antwerp, Wilrijk, Belgium
- Department of Pediatrics, Antwerp University Hospital, Edegem, Belgium
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Tabata H, Enseki M, Nukaga M, Hirai K, Matsuda S, Furuya H, Kato M, Mochizuki H. Changes in the breath sound spectrum during methacholine inhalation in children with asthma. Respirology 2017; 23:168-175. [PMID: 28960780 DOI: 10.1111/resp.13177] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Revised: 07/05/2017] [Accepted: 07/11/2017] [Indexed: 01/24/2023]
Abstract
BACKGROUND AND OBJECTIVE An effort-independent breath sound analysis is expected to be a safe and simple method for clinical assessment of changes in airway function. The effects of bronchoconstriction and bronchodilation on novel breath sound parameters in asthmatic children were investigated. METHODS The study population included 49 children with atopic asthma (male = 33; mean age: 10.2 years). We evaluated breath sound parameters of the highest frequency of the power spectrum (HFp), frequency limiting 50% and 99% of the power spectrum (F50 and F99 ) and roll-off from 600 Hz to the HFp (Slope). We also assessed new parameters obtained using the ratios of sound spectrum parameters (spectrum curve indices), such as the ratio of the third and fourth power area to the total power area (P3 /PT and P4 /PT ), the ratio of the third and fourth areas to the total area under the curve (A3 /AT and B4 /AT ) and the ratio of power and frequency at 75% of HFp and 50% of HFp (RPF75 and RPF50 ). This was measured before and after methacholine inhalation challenge and after β2 agonist inhalation. RESULTS The parameters, F50 and F99 , showed no changes after methacholine inhalation. Conversely, the A3 /AT (12.5-10.0%, P < 0.001), B4 /AT (7.6-5.5%, P < 0.001), RPF75 (6.7-4.0 dBm/Hz, P < 0.001) and RPF50 (5.8-4.3 dBm/Hz, P < 0.001) were significantly decreased. These values returned to the original level after β2 agonist inhalation. CONCLUSION Spectrum curve indices indicate bronchoconstriction and bronchodilation. These parameters may play a role in the assessment of airway narrowing in asthmatic children.
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Affiliation(s)
- Hideyuki Tabata
- Department of Pediatrics, Tokai University School of Medicine, Isehara, Japan
| | - Mayumi Enseki
- Department of Pediatrics, Tokai University School of Medicine, Isehara, Japan
| | - Mariko Nukaga
- Department of Pediatrics, Tokai University School of Medicine, Isehara, Japan
| | - Kota Hirai
- Department of Pediatrics, Tokai University School of Medicine, Isehara, Japan
| | - Shinichi Matsuda
- Department of Pediatrics, Tokai University School of Medicine, Isehara, Japan
| | - Hiroyuki Furuya
- Department of Basic Clinical Science and Public Health, Tokai University School of Medicine, Isehara, Japan
| | - Masahiko Kato
- Department of Pediatrics, Tokai University School of Medicine, Isehara, Japan
| | - Hiroyuki Mochizuki
- Department of Pediatrics, Tokai University School of Medicine, Isehara, Japan
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Enseki M, Nukaga M, Tabata H, Hirai K, Matsuda S, Mochizuki H. A clinical method for detecting bronchial reversibility using a breath sound spectrum analysis in infants. Respir Investig 2017; 55:219-228. [PMID: 28427749 DOI: 10.1016/j.resinv.2016.11.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Revised: 11/02/2016] [Accepted: 11/18/2016] [Indexed: 12/18/2022]
Abstract
BACKGROUND Using a breath sound analyzer, we investigated clinical parameters for detecting bronchial reversibility in infants. METHODS A total of 59 infants (4-39 months, mean age 7.8 months) were included. In Study 1, the intra- and inter-observer variability was measured in 23 of 59 infants. Breath sound parameters, the frequency at 99% of the maximum frequency (F99), frequency at 25%, 50%, and 75% of the power spectrum (Q25, Q50, and Q75), and highest frequency of inspiratory breath sounds (HFI), and parameters obtained using the ratio of parameters, i.e. spectrum curve indices, the ratio of the third and fourth area to total area (A3/AT and B4/AT, respectively) and ratio of power and frequency at F75 and F50 (RPF75 and RPF50), were calculated. In Study 2, the relationship between parameters of breath sounds and age and stature were studied. In Study 3, breath sounds were studied before and after β2 agonist inhalation. RESULTS In Study 1, the data showed statistical intra- and inter-observer reliability in A3/AT (p=0.042 and 0.034, respectively) and RPF50 (p=0.001 and 0.001, respectively). In Study 2, there were no significant relationships between age, height, weight, and BMI. In Study 3, A3/AT and RPF50 significantly changed after β2 agonist inhalation (p=0.001 and p<0.001, respectively). CONCLUSIONS Breath sound analysis can be performed in infants, as in older children, and the spectrum curve indices are not significantly affected by age-related factors. These sound parameters may play a role in the assessment of bronchial reversibility in infants.
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Affiliation(s)
- Mayumi Enseki
- Department of Pediatrics, Tokai University School of Medicine, Shimokasuya 143, Isehara, Kanagawa 259-1193, Japan.
| | - Mariko Nukaga
- Department of Pediatrics, Tokai University School of Medicine, Shimokasuya 143, Isehara, Kanagawa 259-1193, Japan.
| | - Hideyuki Tabata
- Department of Pediatrics, Tokai University School of Medicine, Shimokasuya 143, Isehara, Kanagawa 259-1193, Japan.
| | - Kota Hirai
- Department of Pediatrics, Tokai University School of Medicine, Shimokasuya 143, Isehara, Kanagawa 259-1193, Japan.
| | - Shinichi Matsuda
- Department of Pediatrics, Tokai University School of Medicine, Shimokasuya 143, Isehara, Kanagawa 259-1193, Japan.
| | - Hiroyuki Mochizuki
- Department of Pediatrics, Tokai University School of Medicine, Shimokasuya 143, Isehara, Kanagawa 259-1193, Japan.
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Lung sound analysis can be an index of the control of bronchial asthma. Allergol Int 2017; 66:64-69. [PMID: 27312512 DOI: 10.1016/j.alit.2016.05.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2015] [Revised: 04/10/2016] [Accepted: 05/01/2016] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND We assessed whether lung sound analysis (LSA) is a valid measure of airway obstruction and inflammation in patients with bronchial asthma during treatment with inhaled corticosteroids (ICSs). METHODS 63 good adherence patients with bronchial asthma and 18 poor adherence patients were examined by LSA, spirometry, fractional exhaled nitric oxide (FeNO), and induced sputum. The expiration-to-inspiration lung sound power ratio at low frequencies between 100 and 200 Hz (E/I LF) obtained by LSA was compared between healthy volunteers and bronchial asthma patients. Next, post-ICS treatment changes were compared in bronchial asthma patients between the good adherence patients and the poor adherence patients. RESULTS E/I LF was significantly higher in bronchial asthma patients (0.62 ± 0.21) than in healthy volunteers (0.44 ± 0.12, p < 0.001). The good adherence patients demonstrated a significant reduction in E/I LF from pre-treatment to post-treatment (0.55 ± 0.21 to 0.46 ± 0.16, p = 0.002), whereas the poor adherence patients did not show a significant change. The decrease of E/I LF correlated with the improvement of FEV1/FVC ratio during the ICS treatment (r = -0.26, p = 0.04). The subjects with higher pre-treatment E/I LF values had significantly lower FEV1/FVC and V50,%pred (p < 0.001), and significantly higher FeNO and sputum eosinophil percentages (p = 0.008 and p < 0.001, respectively). CONCLUSIONS The E/I LF measurement obtained by LSA is useful as an indicator of changes in airway obstruction and inflammation and can be used for monitoring the therapeutic course of bronchial asthma patients.
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Shimoda T, Obase Y, Nagasaka Y, Kishikawa R, Mukae H, Iwanaga T. Peripheral bronchial obstruction evaluation in patients with asthma by lung sound analysis and impulse oscillometry. Allergol Int 2017; 66:132-138. [PMID: 27516132 DOI: 10.1016/j.alit.2016.06.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Revised: 05/23/2016] [Accepted: 06/20/2016] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND Computer-aided lung sound analysis (LSA) has been reported to be useful for evaluating airway inflammation and obstruction in asthma patients. We investigated the relation between LSA and impulse oscillometry with the evaluation of peripheral airway obstruction. METHODS A total of 49 inhaled corticosteroid-naive bronchial asthma patients underwent LSA, spirometry, impulse oscillometry, and airway hyperresponsiveness testing. The data were analyzed to assess correlations between the expiration: inspiration lung sound power ratio (dB) at low frequencies between 100 and 195 Hz (E/I LF) and various parameters. RESULTS E/I LF and X5 were identified as independent factors that affect V˙50,%predicted. E/I LF showed a positive correlation with R5 (r = 0.34, p = 0.017), R20 (r = 0.34, p = 0.018), reactance area (AX, r = 0.40, p = 0.005), and resonant frequency of reactance (Fres, r = 0.32, p = 0.024). A negative correlation was found between E/I LF and X5 (r = -0.47, p = 0.0006). E/I LF showed a negative correlation with FEV1/FVC(%), FEV1,%predicted, V˙50,%predicted, and V˙25,%predicted (r = -0.41, p = 0.003; r = -0.44, p = 0.002; r = -0.49, p = 0.0004; and r = -0.30, p = 0.024, respectively). E/I LF was negatively correlated with log PC20 (r = -0.30, p = 0.024). Log PC20, X5, and past smoking were identified as independent factors that affected E/I LF level. CONCLUSIONS E/I LF as with X5 can be an indicator of central and peripheral airway obstruction in bronchial asthma patients.
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Affiliation(s)
- Terufumi Shimoda
- Clinical Research Center, Fukuoka National Hospital, Fukuoka, Japan.
| | - Yasushi Obase
- Department of Respiratory Medicine, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | | | - Reiko Kishikawa
- Clinical Research Center, Fukuoka National Hospital, Fukuoka, Japan
| | - Hiroshi Mukae
- Department of Respiratory Medicine, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - Tomoaki Iwanaga
- Clinical Research Center, Fukuoka National Hospital, Fukuoka, Japan
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Azad MK, Mansy HA, Gamage PT. Geometric features of pig airways using computed tomography. Physiol Rep 2016; 4:4/20/e12995. [PMID: 27798351 PMCID: PMC5099960 DOI: 10.14814/phy2.12995] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Accepted: 09/12/2016] [Indexed: 11/24/2022] Open
Abstract
Accurate knowledge of the airway geometry is needed when constructing physical models of the airway tree and for numerical modeling of flow or sound propagation in the airways. Human and animal experiments are conducted to validate these models. Many studies documented the geometric details of the human airways. However, information about the geometry of pig airways is scarcer. Earlier studies suggested that the morphology of animal airways can be significantly different from that of humans. The objective of this study is to measure the airway diameter, length and bifurcation angles in domestic pigs using computed tomography. In this study, lungs of six pigs were imaged, then segmentation software tools were used to extract the geometry of the airway lumen. The airway dimensions were measured from the resulting 3‐D models for the first 24 airway generations. Results showed that the size and morphology of the airways of the six pigs were similar. The trachea diameters were found to be comparable to the typical human adult, but the diameter, length and branching angles of other airways were noticeably different from that of humans. For example, pig airways consistently had an early branching from the trachea that feeds the top right lung lobe and precedes the main carina. This branch is absent in the human airways. The results suggested that the pig airways geometry may not be accurately approximated by human airways and this approximation may contribute to increasing the errors in computational models of the pig chest.
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Affiliation(s)
- Md K Azad
- Biomedical Acoustics Research Laboratory, Department of Mechanical and Aerospace Engineering, University of Central Florida, Orlando, Florida .,Rush University Medical Center, Chicago, Illinois
| | - Hansen A Mansy
- Biomedical Acoustics Research Laboratory, Department of Mechanical and Aerospace Engineering, University of Central Florida, Orlando, Florida.,Rush University Medical Center, Chicago, Illinois
| | - Peshala T Gamage
- Biomedical Acoustics Research Laboratory, Department of Mechanical and Aerospace Engineering, University of Central Florida, Orlando, Florida.,Rush University Medical Center, Chicago, Illinois
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Azad MK, Mansy HA. Generation of Pig Airways using Rules Developed from the Measurements of Physical Airways. ACTA ACUST UNITED AC 2016; 6. [PMID: 28255517 DOI: 10.4172/2155-9538.1000203] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND A method for generating bronchial tree would be helpful when constructing models of the tree for benchtop experiments as well as for numerical modeling of flow or sound propagation in the airways. Early studies documented the geometric details of the human airways that were used to develop methods for generating human airway tree. However, methods for generating animal airway tree are scarcer. Earlier studies suggested that the morphology of animal airways can be significantly different from that of humans. Hence, using algorithms for the human airways may not be accurate in generating models of animal airway geometry. OBJECTIVE The objective of this study is to develop an algorithm for generating pig airway tree based on the geometric details extracted from the physical measurements. METHODS In the current study, measured values of branch diameters, lengths and bifurcation angles and rotation of bifurcating planes were used to develop an algorithm that is capable of generating a realistic pig airway tree. RESULTS The generation relations between parent and daughter branches were found to follow certain trends. The diameters and the length of different branches were dependent on airway generations while the bifurcation angles were primarily dependent on bifurcation plane rotations. These relations were sufficient to develop rules for generating a model of the pig large airways. CONCLUSION The results suggested that the airway tree generated from the algorithm can provide an approximate geometric model of pig airways for computational and benchtop studies.
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Affiliation(s)
- Md Khurshidul Azad
- Biomedical Acoustics Research Laboratory, University of Central Florida, United States
| | - Hansen A Mansy
- Biomedical Acoustics Research Laboratory, University of Central Florida, United States
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Tabata H, Hirayama M, Enseki M, Nukaga M, Hirai K, Furuya H, Mochizuki H. A novel method for detecting airway narrowing using breath sound spectrum analysis in children. Respir Investig 2015; 54:20-8. [PMID: 26718141 DOI: 10.1016/j.resinv.2015.07.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Revised: 07/22/2015] [Accepted: 07/24/2015] [Indexed: 10/23/2022]
Abstract
BACKGROUND Using a breath sound analyzer, we investigated new clinical parameters that are rarely affected by airflow in young children. METHODS A total of 65 children with asthma participated in this study (mean age 9.6 years). In Study 1, the intra- and inter-observer variability was measured. Common breath sound parameters, frequency at 99%, 75%, and 50% of the maximum frequency (F99, F75, and F50) and the highest frequency of inspiratory breath sounds were calculated. In addition, new parameters obtained using the ratio of sound spectra parameters, i.e., the spectrum curve indexes including the ratio of the third and fourth area to the total area and the ratio of power and frequency at F75 and F50, were calculated. In Study 2, 51 children underwent breath sound analyses. In Study 3, breath sounds were studied before and after methacholine inhalation. RESULTS In Study 1, the data showed good inter- and intra-observer reliability. In Study 2, there were significant relationships between the airflow rate, age, height, and spirometric and common breath sound parameters. However, there were no significant relationships between the airflow rate and the spectrum curve indexes. Moreover, the spectrum curve indexes showed no relationships with age, height, or spirometric parameters. In Study 3, all parameters significantly changed after methacholine inhalation. CONCLUSIONS Some spectrum curve indexes are not significantly affected by the airflow rate at the mouth, although they successfully indicate airway narrowing. These parameters may play a role in the assessment of bronchoconstriction in children.
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Affiliation(s)
- Hideyuki Tabata
- Department of Pediatrics, Tokai University School of Medicine, Shimokasuya 143, Isehara, Kanagawa 259-1193, Japan.
| | - Mariko Hirayama
- Department of Pediatrics, Tokai University School of Medicine, Shimokasuya 143, Isehara, Kanagawa 259-1193, Japan.
| | - Mayumi Enseki
- Department of Pediatrics, Tokai University School of Medicine, Shimokasuya 143, Isehara, Kanagawa 259-1193, Japan.
| | - Mariko Nukaga
- Department of Pediatrics, Tokai University School of Medicine, Shimokasuya 143, Isehara, Kanagawa 259-1193, Japan.
| | - Kota Hirai
- Department of Pediatrics, Tokai University School of Medicine, Shimokasuya 143, Isehara, Kanagawa 259-1193, Japan.
| | - Hiroyuki Furuya
- Department of Basic Clinical Science and Public Health, Tokai University School of Medicine, Shimokasuya 143, Isehara, Kanagawa 259-1193, Japan.
| | - Hiroyuki Mochizuki
- Department of Pediatrics, Tokai University School of Medicine, Shimokasuya 143, Isehara, Kanagawa 259-1193, Japan.
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Mineshita M, Shirakawa T, Saji J, Handa H, Furuya N, Kida H, Nishine H, Nobuyama S, Inoue T, Miyazawa T. Vibration response imaging in healthy Japanese subjects. Respir Investig 2013; 52:28-35. [PMID: 24388368 DOI: 10.1016/j.resinv.2013.05.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2012] [Revised: 05/26/2013] [Accepted: 05/30/2013] [Indexed: 10/26/2022]
Abstract
BACKGROUND Vibration response imaging (VRI) records the intensity and distribution of lung sounds during the respiration cycle. Our objective was to analyze VRI findings in healthy Japanese adults. METHODS VRI images of 106 healthy subjects (33.7±9.6 years, 52 male and 54 female), including 67 nonsmokers and 39 asymptomatic smokers, were recorded. The regional intensity of vibrations was assessed using quantitative lung data (QLD), and VRI dynamic images by rater assessment, left and right lung asynchrony (gap index), and regional lung asynchrony (asynchrony score). RESULTS A dominance of total left lung QLD was observed in all subjects, and this phenomenon was more prominent in female subjects. However, there was no significant difference between the total left and total right lung QLD in smokers. Rater assessments showed that 81.1% of all subjects had a normal final assessment. Male subjects had a significantly higher percentage of good or normal assessments for all image scores, except dynamic image scoring. The asynchrony score was significantly higher in female subjects. There were no significant differences in these qualitative assessments between non-smokers and smokers. CONCLUSIONS Although our QLD results were similar to those of a previous report, there were discrepancies between sexes for the qualitative assessments. A significantly higher number of female subjects had abnormal images as assessed by the raters. Furthermore, significantly higher asynchrony scores were observed in female subjects. The VRI variability in sex may be considered normal among the Japanese population. This study is registered with UMIN-CTR under registration number UMIN000002355.
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Affiliation(s)
- Masamichi Mineshita
- Division of Respiratory and Infectious Diseases, Department of Internal Medicine, St. Marianna University School of Medicine, Kawasaki, Japan.
| | - Taeko Shirakawa
- Division of Respiratory and Infectious Diseases, Department of Internal Medicine, St. Marianna University School of Medicine, Kawasaki, Japan.
| | - Junko Saji
- Division of Respiratory and Infectious Diseases, Department of Internal Medicine, St. Marianna University School of Medicine, Kawasaki, Japan.
| | - Hiroshi Handa
- Division of Respiratory and Infectious Diseases, Department of Internal Medicine, St. Marianna University School of Medicine, Kawasaki, Japan.
| | - Naoki Furuya
- Division of Respiratory and Infectious Diseases, Department of Internal Medicine, St. Marianna University School of Medicine, Kawasaki, Japan.
| | - Hirotaka Kida
- Division of Respiratory and Infectious Diseases, Department of Internal Medicine, St. Marianna University School of Medicine, Kawasaki, Japan.
| | - Hiroki Nishine
- Division of Respiratory and Infectious Diseases, Department of Internal Medicine, St. Marianna University School of Medicine, Kawasaki, Japan.
| | - Seiichi Nobuyama
- Division of Respiratory and Infectious Diseases, Department of Internal Medicine, St. Marianna University School of Medicine, Kawasaki, Japan.
| | - Takeo Inoue
- Division of Respiratory and Infectious Diseases, Department of Internal Medicine, St. Marianna University School of Medicine, Kawasaki, Japan.
| | - Teruomi Miyazawa
- Division of Respiratory and Infectious Diseases, Department of Internal Medicine, St. Marianna University School of Medicine, Kawasaki, Japan.
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Mansy HA, O'Connor CJ, Balk RA, Sandler RH. Breath sound changes associated with malpositioned endotracheal tubes. Med Biol Eng Comput 2005; 43:206-11. [PMID: 15865129 DOI: 10.1007/bf02345956] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Endotracheal tubes (ETTs) are used to establish airway access in patients with ventilatory failure and during general anaesthesia. Tube malpositioning can compromise respiratory function and can be associated with increased morbidity and mortality. Clinical assessment of ETT position normally involves chest auscultation, which is highly skill-dependent and can be misleading. The objective of this pilot study was to investigate breath sound changes associated with ETT malpositioning. Breath sounds were acquired in six human subjects over each hemithorax and over the epigastrium for tracheal, bronchial and oesophageal intubations. When the ETT was in the oesophagus, the acoustic energy ratio between epigastrium and chest surface increased in all subjects (p < 0.04). In addition, ETT placement in the right mainstem bronchus decreased the acoustic energy ratio between the left and right hemithoraxes in all subjects (p < 0.04). A baseline measurement of this energy ratio was needed for bronchial intubation identification. However, using this ratio after bandpass filtering (200-500 Hz) did not require a baseline value, which would increase the utility of this method for initial ETT placement. These results suggest that computerised analysis of breath sounds may be useful for assessment of ETT positioning. More studies are needed to test the feasibility of this approach further.
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Affiliation(s)
- H A Mansy
- Biomedical Acoustics Research Group, Department of Pediatrics, Rush Medical College, Chicago, IL, USA.
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Sera T, Satoh S, Horinouchi H, Kobayashi K, Tanishita K. Respiratory flow in a realistic tracheostenosis model. J Biomech Eng 2003; 125:461-71. [PMID: 12968570 DOI: 10.1115/1.1589775] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The possible mechanism of wheeze generation in tracheostenosis was identified by measuring inspiratory and expiratory flow in a "morphological and distensible" realistic tracheostenosis model. The shape of the model was based on CT (Computed Tomography) images of a patient that had tracheostenosis. A trachea consists of tracheal cartilage rings and smooth muscle. Spatial variation of wall distensibility was achieved in the model by varying the wall thickness based on the elastic modulus measured in pig airways. The spatial variation influenced the flow in the airway and the turbulence production rate decreased faster at smooth muscles. Using the model, we investigated the mechanism of wheeze generation by focusing on the turbulence intensity. The turbulence intensity in expiratory flow was about twice that in inspiratory flow, and larger vortices existed in post-stenosis in expiratory flow, and thus might contribute to wheeze generation.
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Affiliation(s)
- Toshihiro Sera
- Center for Life Science and Technology, School of Fundamental Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, 223-8522, Japan.
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Kiyokawa H, Pasterkamp H. Volume-dependent variations of regional lung sound, amplitude, and phase. J Appl Physiol (1985) 2002; 93:1030-8. [PMID: 12183500 DOI: 10.1152/japplphysiol.00110.2002] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Acoustic imaging of the respiratory system demonstrates regional changes of lung sounds that correspond to pulmonary ventilation. We investigated volume-dependent variations of lung sound phase and amplitude between two closely spaced sensors in five adults. Lung sounds were recorded at the posterior right upper, right lower, and left lower lobes during targeted breathing (1.2 +/- 0.2 l/s; volume = 20-50 and 50-80% of vital capacity) and passive sound transmission (< or =0.2 l/s; volumes as above). Average sound amplitudes were obtained after band-pass filtering to 75-150, 150-300, and 300-600 Hz. Cross correlation established the phase relation of sound between sensors. Volume-dependent variations in phase (< or =1.5 ms) and amplitude (< or =11 dB) were observed at the lower lobes in the 150- to 300-Hz band. During inspiration, increasing delay and amplitude of sound at the caudal relative to the cranial sensor were also observed during passive transmission in several subjects. This previously unrecognized behavior of lung sounds over short distances might reflect spatial variations of airways and diaphragms during breathing.
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Affiliation(s)
- Hiroshi Kiyokawa
- Department of Pediatrics and Child Health, University of Manitoba, Winnipeg, Manitoba, Canada R3C 3J7
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Mansy HA, Royston TJ, Balk RA, Sandler RH. Pneumothorax detection using computerised analysis of breath sounds. Med Biol Eng Comput 2002; 40:526-32. [PMID: 12452412 DOI: 10.1007/bf02345450] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
The primary objective of the study was to investigate the effects of pneumothorax (PTX) on breath sounds and to evaluate their use for PTX diagnosis. The underlying hypothesis is that there are diagnostic breath sound changes with PTX. An animal model was created in which breath sounds of eight mongrel dogs were acquired and analysed for both normal and PTX states. The results suggested that pneumothorax was associated with a reduction in sound amplitude, a preferential decrease in high-frequency acoustic components and a reduction in sound amplitude variation during the respiration cycle (p<0.01 for each, using the Wilcoxson signed-rank test). Although the use of diminished sound amplitude for PTX diagnosis assumes availability of baseline measurements, this appears unnecessary for high-frequency reduction or sound amplitude changes over the respiratory cycle. Further studies are warranted to test the clinical feasibility of the method in humans.
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Affiliation(s)
- H A Mansy
- Biomedical Acoustics Research Group, Department of Pediatrics, Rush Medical College, Chicago, USA.
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Beiträge zum Workshop. BIOMED ENG-BIOMED TE 2000. [DOI: 10.1515/bmte.2000.45.s2.11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Kraman SS, Pasterkamp H, Kompis M, Takase M, Wodicka GR. Effects of breathing pathways on tracheal sound spectral features. RESPIRATION PHYSIOLOGY 1998; 111:295-300. [PMID: 9628234 DOI: 10.1016/s0034-5687(97)00113-8] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The spectra of sounds recorded over the trachea of adults typically reveal peaks near 700 and 1500 Hz. We assessed the anatomical determinants of these peaks and the conditions contributing to their presence. We studied five adult subjects with normal lung function, measuring sounds at the suprasternal notch and on the right cheek. The subjects breathed at target airflows of 15 and at 30 ml sec(-1) kg(-1) both through the mouth with nose clips and then through the mouth and nose using a cushioned face mask. The mouth breathing maneuvers were performed with three lengths (3.6, 21.1 and 38.6 cm) of 2.6 cm diameter tubing between the mouth and the pneumotachograph. The nose breathing maneuver was performed with the longest tube (between the mask and pneumotachograph). The signals occurring at the target flows +/- 20% were used to create averaged, spectral estimates. We found that all subjects had two predominant spectral peaks; a approximately 700 Hz peak loudest over the cheek and a approximately 1500 Hz peak loudest over the trachea. The frequency of both peaks negatively correlated with body height (and presumably, airway length). There was no systematic effect of breathing phase, flow rate or length of the tube connecting the mouth to the pneumotachograph on the spectral peaks. Breathing into the mask and breathing through the nose did markedly alter the spectra. We conclude that the higher tracheal sound peak reflects resonance within the major airways and is relatively independent of extrathoracic influences during mouth breathing through a tube.
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Affiliation(s)
- S S Kraman
- VA Medical Center, Lexington, Kentucky 40511, USA.
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Pasterkamp H, Kraman SS, Wodicka GR. Respiratory sounds. Advances beyond the stethoscope. Am J Respir Crit Care Med 1997; 156:974-87. [PMID: 9310022 DOI: 10.1164/ajrccm.156.3.9701115] [Citation(s) in RCA: 281] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Affiliation(s)
- H Pasterkamp
- Department of Pediatrics and Child Health, University of Manitoba, Winnipeg, Canada
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Fiz Fernández J. Sonidos respiratorios. Arch Bronconeumol 1995. [DOI: 10.1016/s0300-2896(15)30938-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Schreur HJ, Vanderschoot J, Zwinderman AH, Dijkman JH, Sterk PJ. Abnormal lung sounds in patients with asthma during episodes with normal lung function. Chest 1994; 106:91-9. [PMID: 8020326 DOI: 10.1378/chest.106.1.91] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Even in patients with clinically stable asthma with normal lung function, the airways are characterized by inflammatory changes, including mucosal swelling. In order to investigate whether lung sounds can distinguish these subjects from normal subjects, we compared lung sound characteristics between eight normal and nine symptom-free subjects with mild asthma. All subjects underwent simultaneous recordings of airflow, lung volume changes, and lung sounds during standardized quiet breathing, and during forced maneuvers. Flow-dependent power spectra were computed using fast Fourier transform. For each spectrum we determined lung sound intensity (LSI), frequencies (Q25%, Q50%, Q75%) wheezing (W), and W%. The results were analyzed by ANOVA. During expiration, LSI was lower in patients with asthma than in healthy controls, in particular at relatively low airflow values. During quiet expiration, Q25% to Q75% were higher in asthmatics than in healthy controls, while the change of Q25% to Q75% with flow was greater in asthmatic than in normal subjects. The W and W% were not different between the subject groups. The results indicate that at given airflows, lung sounds are lower in intensity and higher in pitch in asthmatics as compared with controls. This suggests that the generation and/or transmission of lung sounds in symptom-free patients with stable asthma differ from that in normal subjects, even when lung function is within the normal range. Therefore, airflow standardized phonopneumography might reflect morphologic changes in airways of patients with asthma.
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Affiliation(s)
- H J Schreur
- Department of Pulmonology, University Hospital of Leiden, The Netherlands
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Schreur HJ, Sterk PJ, Vanderschoot J, van Klink HC, van Vollenhoven E, Dijkman JH. Lung sound intensity in patients with emphysema and in normal subjects at standardised airflows. Thorax 1992; 47:674-9. [PMID: 1440459 PMCID: PMC474797 DOI: 10.1136/thx.47.9.674] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
BACKGROUND A common auscultatory finding in pulmonary emphysema is a reduction of lung sounds. This might be due to a reduction in the generation of sounds due to the accompanying airflow limitation or to poor transmission of sounds due to destruction of parenchyma. Lung sound intensity was investigated in normal and emphysematous subjects in relation to airflow. METHODS Eight normal men (45-63 years, FEV1 79-126% predicted) and nine men with severe emphysema (50-70 years, FEV1 14-63% predicted) participated in the study. Emphysema was diagnosed according to pulmonary history, results of lung function tests, and radiographic criteria. All subjects underwent phonopneumography during standardised breathing manoeuvres between 0.5 and 2 1 below total lung capacity with inspiratory and expiratory target airflows of 2 and 1 l/s respectively during 50 seconds. The synchronous measurements included airflow at the mouth and lung volume changes, and lung sounds at four locations on the right chest wall. For each microphone airflow dependent power spectra were computed by using fast Fourier transformation. Lung sound intensity was expressed as log power (in dB) at 200 Hz at inspiratory flow rates of 1 and 2 l/s and at an expiratory flow rate of 1 l/s. RESULTS Lung sound intensity was well repeatable on two separate days, the intraclass correlation coefficient ranging from 0.77 to 0.94 between the four microphones. The intensity was strongly influenced by microphone location and airflow. There was, however, no significant difference in lung sound intensity at any flow rate between the normal and the emphysema group. CONCLUSION Airflow standardised lung sound intensity does not differ between normal and emphysematous subjects. This suggests that the auscultatory finding of diminished breath sounds during the regular physical examination in patients with emphysema is due predominantly to airflow limitation.
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Affiliation(s)
- H J Schreur
- Department of Pulmonology, University of Leiden, The Netherlands
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