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Sarkar M, Madabhavi I. Vocal resonance: a narrative review. Monaldi Arch Chest Dis 2024. [PMID: 38572699 DOI: 10.4081/monaldi.2024.2911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Accepted: 03/18/2024] [Indexed: 04/05/2024] Open
Abstract
Physical examination is an important ritual of bedside medicine that establishes a strong bond between the patient and the physician. It provides practice to acquire important diagnostic skills. A poorly executed bedside examination may result in the wrong diagnosis and adverse outcomes. However, the ritual of obtaining a patient's history and performing a good clinical examination is declining globally. Even the quality of clinical examination skills is declining. One reason may be the short time spent by physicians at the bedside of patients. In addition, due to the substantial technological advancement, physicians often rely more on technology and consider clinical examinations less relevant. In resource-limited settings, thorough history-taking and physical examinations should always be prioritized. An important aspect of respiratory auscultation is the auscultation over the chest wall to detect abnormalities in the transmission of voice-generated sounds, which may provide an important diagnostic clue. Laënnec originally described in detail three types of voice-generated sounds and named them bronchophonism, pectoriloquism, and egophonism. Subsequently, they are known as bronchophony, whispering pectoriloquy, and egophony. A recent variant of egophony is "E-to-A" changes. We searched PubMed, EMBASE, and the CINAHL from inception to December 2023. We used the following search terms: vocal resonance, bronchophony, egophony, whispering pectoriloquy, auscultation, etc. All types of studies were chosen. This review will narrate the physics of sound waves, the types of vocal resonance, the mechanisms of vocal resonance, the methods to elicit them, and the accuracy of vocal resonance.
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Affiliation(s)
- Malay Sarkar
- Department of Pulmonary Medicine, Indira Gandhi Medical College, Shimla, Himachal Pradesh.
| | - Irappa Madabhavi
- Department of Medical and Pediatric Oncology, J N Medical College, KLE Academy of Higher Education and Research, Belagavi, Karnataka.
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Lee CS, Li M, Lou Y, Abbasi QH, Imran MA. Acoustic Lung Imaging Utilized in Continual Assessment of Patients with Obstructed Airway: A Systematic Review. SENSORS (BASEL, SWITZERLAND) 2023; 23:6222. [PMID: 37448069 DOI: 10.3390/s23136222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 07/03/2023] [Accepted: 07/04/2023] [Indexed: 07/15/2023]
Abstract
Smart respiratory therapy is enabled by continual assessment of lung functions. This systematic review provides an overview of the suitability of equipment-to-patient acoustic imaging in continual assessment of lung conditions. The literature search was conducted using Scopus, PubMed, ScienceDirect, Web of Science, SciELO Preprints, and Google Scholar. Fifteen studies remained for additional examination after the screening process. Two imaging modalities, lung ultrasound (LUS) and vibration imaging response (VRI), were identified. The most common outcome obtained from eleven studies was positive observations of changes to the geographical lung area, sound energy, or both, while positive observation of lung consolidation was reported in the remaining four studies. Two different modalities of lung assessment were used in eight studies, with one study comparing VRI against chest X-ray, one study comparing VRI with LUS, two studies comparing LUS to chest X-ray, and four studies comparing LUS in contrast to computed tomography. Our findings indicate that the acoustic imaging approach could assess and provide regional information on lung function. No technology has been shown to be better than another for measuring obstructed airways; hence, more research is required on acoustic imaging in detecting obstructed airways regionally in the application of enabling smart therapy.
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Affiliation(s)
- Chang-Sheng Lee
- James Watt School of Engineering, University of Glasgow, Glasgow G12 8QQ, UK
- Global Technology and Innovation Department, Hill-Rom Services Pte Ltd., Singapore 768923, Singapore
| | - Minghui Li
- James Watt School of Engineering, University of Glasgow, Glasgow G12 8QQ, UK
| | - Yaolong Lou
- Global Technology and Innovation Department, Hill-Rom Services Pte Ltd., Singapore 768923, Singapore
| | - Qammer H Abbasi
- James Watt School of Engineering, University of Glasgow, Glasgow G12 8QQ, UK
| | - Muhammad Ali Imran
- James Watt School of Engineering, University of Glasgow, Glasgow G12 8QQ, UK
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3
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GTCC-based BiLSTM deep-learning framework for respiratory sound classification using empirical mode decomposition. Neural Comput Appl 2021. [DOI: 10.1007/s00521-021-06295-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Habukawa C, Ohgami N, Arai T, Makata H, Tomikawa M, Fujino T, Manabe T, Ogihara Y, Ohtani K, Shirao K, Sugai K, Asai K, Sato T, Murakami K. Wheeze Recognition Algorithm for Remote Medical Care Device in Children: Validation Study. JMIR Pediatr Parent 2021; 4:e28865. [PMID: 33875413 PMCID: PMC8277407 DOI: 10.2196/28865] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 04/16/2021] [Accepted: 04/16/2021] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Since 2020, peoples' lifestyles have been largely changed due to the COVID-19 pandemic worldwide. In the medical field, although many patients prefer remote medical care, this prevents the physician from examining the patient directly; thus, it is important for patients to accurately convey their condition to the physician. Accordingly, remote medical care should be implemented and adaptable home medical devices are required. However, only a few highly accurate home medical devices are available for automatic wheeze detection as an exacerbation sign. OBJECTIVE We developed a new handy home medical device with an automatic wheeze recognition algorithm, which is available for clinical use in noisy environments such as a pediatric consultation room or at home. Moreover, the examination time is only 30 seconds, since young children cannot endure a long examination time without crying or moving. The aim of this study was to validate the developed automatic wheeze recognition algorithm as a clinical medical device in children at different institutions. METHODS A total of 374 children aged 4-107 months in pediatric consultation rooms of 10 institutions were enrolled in this study. All participants aged ≥6 years were diagnosed with bronchial asthma and patients ≤5 years had reported at least three episodes of wheezes. Wheezes were detected by auscultation with a stethoscope and recorded for 30 seconds using the wheeze recognition algorithm device (HWZ-1000T) developed based on wheeze characteristics following the Computerized Respiratory Sound Analysis guideline, where the dominant frequency and duration of a wheeze were >100 Hz and >100 ms, respectively. Files containing recorded lung sounds were assessed by each specialist physician and divided into two groups: 177 designated as "wheeze" files and 197 as "no-wheeze" files. Wheeze recognitions were compared between specialist physicians who recorded lung sounds and those recorded using the wheeze recognition algorithm. We calculated the sensitivity, specificity, positive predictive value, and negative predictive value for all recorded sound files, and evaluated the influence of age and sex on the wheeze detection sensitivity. RESULTS Detection of wheezes was not influenced by age and sex. In all files, wheezes were differentiated from noise using the wheeze recognition algorithm. The sensitivity, specificity, positive predictive value, and negative predictive value of the wheeze recognition algorithm were 96.6%, 98.5%, 98.3%, and 97.0%, respectively. Wheezes were automatically detected, and heartbeat sounds, voices, and crying were automatically identified as no-wheeze sounds by the wheeze recognition algorithm. CONCLUSIONS The wheeze recognition algorithm was verified to identify wheezing with high accuracy; therefore, it might be useful in the practical implementation of asthma management at home. Only a few home medical devices are available for automatic wheeze detection. The wheeze recognition algorithm was verified to identify wheezing with high accuracy and will be useful for wheezing management at home and in remote medical care.
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Affiliation(s)
- Chizu Habukawa
- Department of Pediatrics, Minami Wakayama Medical Center, Tanabe, Japan
| | | | | | | | | | | | | | | | | | - Kenichiro Shirao
- Shirao Clinic of Pediatrics and Pediatric Allergy, Hiroshima, Japan
| | - Kazuko Sugai
- Sugai Children's Clinic Pediatrics/Allergy, Hiroshima, Japan
| | - Kei Asai
- Omron Healthcare Co, Ltd, Muko, Japan
| | | | - Katsumi Murakami
- Department of Psychosomatic Medicine, Sakai Sakibana Hospital, Sakai, Japan
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Habukawa C, Ohgami N, Matsumoto N, Hashino K, Asai K, Sato T, Murakami K. A wheeze recognition algorithm for practical implementation in children. PLoS One 2020; 15:e0240048. [PMID: 33031408 PMCID: PMC7544038 DOI: 10.1371/journal.pone.0240048] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Accepted: 09/18/2020] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND The detection of wheezes as an exacerbation sign is important in certain respiratory diseases. However, few highly accurate clinical methods are available for automatic detection of wheezes in children. This study aimed to develop a wheeze detection algorithm for practical implementation in children. METHODS A wheeze recognition algorithm was developed based on wheezes features following the Computerized Respiratory Sound Analysis guidelines. Wheezes can be detected by auscultation with a stethoscope and using an automatic computerized lung sound analysis. Lung sounds were recorded for 30 s in 214 children aged 2 months to 12 years and 11 months in a pediatric consultation room. Files containing recorded lung sounds were assessed by two specialist physicians and divided into two groups: 65 were designated as "wheeze" files, and 149 were designated as "no-wheeze" files. All lung sound judgments were agreed between two specialist physicians. We compared wheeze recognition between the specialist physicians and using the wheeze recognition algorithm and calculated the sensitivity, specificity, positive predictive value, and negative predictive value for all recorded sound files to evaluate the influence of age on the wheeze detection sensitivity. RESULTS The detection of wheezes was not influenced by age. In all files, wheezes were differentiated from noise using the wheeze recognition algorithm. The sensitivity, specificity, positive predictive value, and negative predictive value of the wheeze recognition algorithm were 100%, 95.7%, 90.3%, and 100%, respectively. CONCLUSIONS The wheeze recognition algorithm could identify wheezes in sound files and therefore may be useful in the practical implementation of respiratory illness management at home using properly developed devices.
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Affiliation(s)
- Chizu Habukawa
- Department of Paediatrics, Minami Wakayama Medical Center, Wakayama, Japan
| | - Naoto Ohgami
- Clinical Development Department, Technology Development HQ, Development center, Omron Healthcare Co., Ltd, Kyoto, Japan
| | - Naoki Matsumoto
- Core Technology Department, Technology Development HQ, Development Center, Omron Healthcare Co., Ltd, Kyoto, Japan
| | - Kenji Hashino
- Core Technology Department, Technology Development HQ, Development Center, Omron Healthcare Co., Ltd, Kyoto, Japan
| | - Kei Asai
- Clinical Development Department, Technology Development HQ, Development center, Omron Healthcare Co., Ltd, Kyoto, Japan
| | - Tetsuya Sato
- Clinical Development Department, Technology Development HQ, Development center, Omron Healthcare Co., Ltd, Kyoto, Japan
| | - Katsumi Murakami
- Department of Psychosomatic Medicine, Sakai Sakibana Hospital, Osaka, Japan
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Lozano-Garcia M, Davidson CM, Prieto-Ramon C, Moxham J, Rafferty GF, Jolley CJ, Jane R. Spatial Distribution of Normal Lung Sounds in Healthy Individuals under Varied Inspiratory Load and Flow Conditions. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2020; 2020:2744-2747. [PMID: 33018574 DOI: 10.1109/embc44109.2020.9175992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Respiratory sounds yield pertinent information about respiratory function in both health and disease. Normal lung sound intensity is a characteristic that correlates well with airflow and it can therefore be used to quantify the airflow changes and limitations imposed by respiratory diseases. The dual aims of this study are firstly to establish whether previously reported asymmetries in normal lung sound intensity are affected by varying the inspiratory threshold load or the airflow of respiration, and secondly to investigate whether fixed sample entropy can be used as a valid measure of lung sound intensity. Respiratory sounds were acquired from twelve healthy individuals using four contact microphones on the posterior skin surface during an inspiratory threshold loading protocol and a varying airflow protocol. The spatial distribution of the normal lung sounds intensity was examined. During the protocols explored here the normal lung sound intensity in the left and right lungs in healthy populations was found to be similar, with asymmetries of less than 3 dB. This agrees with values reported in other studies. The fixed sample entropy of the respiratory sound signal was also calculated and compared with the gold standard root mean square representation of lung sound intensity showing good agreement.
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Abstract
Recent developments in sensor technology and computational analysis methods enable new strategies to measure and interpret lung acoustic signals that originate internally, such as breathing or vocal sounds, or are externally introduced, such as in chest percussion or airway insonification. A better understanding of these sounds has resulted in a new instrumentation that allows for highly accurate as well as portable options for measurement in the hospital, in the clinic, and even at home. This review outlines the instrumentation for acoustic stimulation and measurement of the lungs. We first review the fundamentals of acoustic lung signals and the pathophysiology of the diseases that these signals are used to detect. Then, we focus on different methods of measuring and creating signals that have been used in recent research for pulmonary disease diagnosis. These new methods, combined with signal processing and modeling techniques, lead to a reduction in noise and allow improved feature extraction and signal classification. We conclude by presenting the results of human subject studies taking advantage of both the instrumentation and signal processing tools to accurately diagnose common lung diseases. This paper emphasizes the active areas of research within modern lung acoustics and encourages the standardization of future work in this field.
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Boehme S, Toemboel FPR, Hartmann EK, Bentley AH, Weinheimer O, Yang Y, Achenbach T, Hagmann M, Kaniusas E, Baumgardner JE, Markstaller K. Detection of inspiratory recruitment of atelectasis by automated lung sound analysis as compared to four-dimensional computed tomography in a porcine lung injury model. Crit Care 2018; 22:50. [PMID: 29475456 PMCID: PMC6389194 DOI: 10.1186/s13054-018-1964-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Accepted: 01/24/2018] [Indexed: 11/21/2022] Open
Abstract
Background Cyclic recruitment and de-recruitment of atelectasis (c-R/D) is a contributor to ventilator-induced lung injury (VILI). Bedside detection of this dynamic process could improve ventilator management. This study investigated the potential of automated lung sound analysis to detect c-R/D as compared to four-dimensional computed tomography (4DCT). Methods In ten piglets (25 ± 2 kg), acoustic measurements from 34 thoracic piezoelectric sensors (Meditron ASA, Norway) were performed, time synchronized to 4DCT scans, at positive end-expiratory pressures of 0, 5, 10, and 15 cmH2O during mechanical ventilation, before and after induction of c-R/D by surfactant washout. 4DCT was post-processed for within-breath variation in atelectatic volume (Δ atelectasis) as a measure of c-R/D. Sound waveforms were evaluated for: 1) dynamic crackle energy (dCE): filtered crackle sounds (600–700 Hz); 2) fast Fourier transform area (FFT area): spectral content above 500 Hz in frequency and above −70 dB in amplitude in proportion to the total amount of sound above −70 dB amplitude; and 3) dynamic spectral coherence (dSC): variation in acoustical homogeneity over time. Parameters were analyzed for global, nondependent, central, and dependent lung areas. Results In healthy lungs, negligible values of Δ atelectasis, dCE, and FFT area occurred. In lavage lung injury, the novel dCE parameter showed the best correlation to Δ atelectasis in dependent lung areas (R2 = 0.88) where c-R/D took place. dCE was superior to FFT area analysis for each lung region examined. The analysis of dSC could predict the lung regions where c-R/D originated. Conclusions c-R/D is associated with the occurrence of fine crackle sounds as demonstrated by dCE analysis. Standardized computer-assisted analysis of dCE and dSC seems to be a promising method for depicting c-R/D. Electronic supplementary material The online version of this article (10.1186/s13054-018-1964-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Stefan Boehme
- Department of Anesthesia, General Intensive Care Medicine and Pain Management, Medical University Vienna, Waehringer Guertel, 18-20, Vienna, Austria. .,Department of Anesthesiology, Medical Center of the Johannes-Gutenberg University Mainz, Mainz, Germany.
| | - Frédéric P R Toemboel
- Department of Anesthesia, General Intensive Care Medicine and Pain Management, Medical University Vienna, Waehringer Guertel, 18-20, Vienna, Austria
| | - Erik K Hartmann
- Department of Anesthesiology, Medical Center of the Johannes-Gutenberg University Mainz, Mainz, Germany
| | - Alexander H Bentley
- Department of Anesthesiology, Medical Center of the Johannes-Gutenberg University Mainz, Mainz, Germany
| | - Oliver Weinheimer
- Department of Diagnostic and Interventional Radiology, Medical Center of the Johannes-Gutenberg University Mainz, Mainz, Germany.,Department of Diagnostic and Interventional Radiology, University Hospital of Heidelberg, Heidelberg, Germany.,Translational Lung Research Center Heidelberg (TLRC), Member of the German Center for Lung Research (DZL), Heidelberg, Germany
| | - Yang Yang
- Department of Diagnostic and Interventional Radiology, Medical Center of the Johannes-Gutenberg University Mainz, Mainz, Germany
| | - Tobias Achenbach
- Department of Diagnostic and Interventional Radiology, Medical Center of the Johannes-Gutenberg University Mainz, Mainz, Germany.,Institute of Diagnostic and Interventional Radiology, St. Vinzenz Hospital, Cologne, Germany
| | - Michael Hagmann
- Center for Medical Statistics, Informatics, and Intelligent Systems, Medical University Vienna, Vienna, Austria
| | - Eugenijus Kaniusas
- Institute of Electrodynamics, Microwave and Circuit Engineering, Vienna University of Technology, Vienna, Austria
| | - James E Baumgardner
- Department of Anesthesiology, University of Pittsburgh Medical Center, Pittsburgh, PA, 15261, USA
| | - Klaus Markstaller
- Department of Anesthesia, General Intensive Care Medicine and Pain Management, Medical University Vienna, Waehringer Guertel, 18-20, Vienna, Austria.,Department of Anesthesiology, Medical Center of the Johannes-Gutenberg University Mainz, Mainz, Germany
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Jiang H, Chen J, Cao J, Mu L, Hu Z, He J. Application of vibration response imaging technology in patients with community-acquired pneumonia before and after the treatment. Exp Ther Med 2017; 13:3433-3437. [PMID: 28587422 PMCID: PMC5450771 DOI: 10.3892/etm.2017.4419] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Accepted: 02/16/2017] [Indexed: 11/05/2022] Open
Abstract
The value of vibration response imaging (VRI) technology in patients with community-acquired pneumonia (CAP) was assessed. The VRI images of 62 cases of CAP patients with normal lung functions before and after treatment were observed and the changes in images before and after treatment were compared. The maximum vibration energy value of CAP patients was 1.64±0.32, patients with unsmoothed vibration energy curve accounted for 88.71%, 41 cases (66.12%) had unordered dynamic images, 56 cases (90.32%) jumping images, 54 cases (87.10%) desynchrony, 58 cases (93.55%) delay and 52 cases (83.87%) showed contrary events. The maximum vibration energy value after treatment was 1.59±0.29 and the difference was not statistically significant (P=0.93). Patients with unsmoothed vibration energy curve accounted for 20.97%, 11 cases (17.74%) appeared as unordered dynamic images, 28 cases (45.16%) of jumping images, 21 cases (33.87%) desynchrony, 18 cases (29.03%) delay and 10 cases (16.13%) with contrary events. The differences of these symptoms before and after treatment were statistically significant. The image scores of CAP patients before treatment were 10.33±1.95, higher (P<0.001) than after treatment (3.49±2.29). In conclusion, the changes of VRI images of CAP patients are relatively obvious and this technology can be used for the evaluation of CAP curative effects.
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Affiliation(s)
- Hongying Jiang
- Department of Respiratory Rehabilitation Center, Beijing Rehabilitation Hospital of Capital Medical University, Beijing 100014, P.R. China
| | - Jichao Chen
- Department of Respiratory Medicine, Aerospace Center Hospital, Beijing 100049, P.R. China
- Aerospace Clinical Medical College of Peking University, Peking University, Beijing 100049, P.R. China
| | - Jinying Cao
- Department of Respiratory Medicine, Aerospace Center Hospital, Beijing 100049, P.R. China
- Aerospace Clinical Medical College of Peking University, Peking University, Beijing 100049, P.R. China
| | - Lan Mu
- Department of Respiratory Medicine, Aerospace Center Hospital, Beijing 100049, P.R. China
- Aerospace Clinical Medical College of Peking University, Peking University, Beijing 100049, P.R. China
| | - Zhenyu Hu
- Department of Respiratory Medicine, Aerospace Center Hospital, Beijing 100049, P.R. China
- Aerospace Clinical Medical College of Peking University, Peking University, Beijing 100049, P.R. China
| | - Jian He
- Department of Respiratory Medicine, Aerospace Center Hospital, Beijing 100049, P.R. China
- Aerospace Clinical Medical College of Peking University, Peking University, Beijing 100049, P.R. China
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Pramono RXA, Bowyer S, Rodriguez-Villegas E. Automatic adventitious respiratory sound analysis: A systematic review. PLoS One 2017; 12:e0177926. [PMID: 28552969 PMCID: PMC5446130 DOI: 10.1371/journal.pone.0177926] [Citation(s) in RCA: 88] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Accepted: 05/05/2017] [Indexed: 12/03/2022] Open
Abstract
Background Automatic detection or classification of adventitious sounds is useful to assist physicians in diagnosing or monitoring diseases such as asthma, Chronic Obstructive Pulmonary Disease (COPD), and pneumonia. While computerised respiratory sound analysis, specifically for the detection or classification of adventitious sounds, has recently been the focus of an increasing number of studies, a standardised approach and comparison has not been well established. Objective To provide a review of existing algorithms for the detection or classification of adventitious respiratory sounds. This systematic review provides a complete summary of methods used in the literature to give a baseline for future works. Data sources A systematic review of English articles published between 1938 and 2016, searched using the Scopus (1938-2016) and IEEExplore (1984-2016) databases. Additional articles were further obtained by references listed in the articles found. Search terms included adventitious sound detection, adventitious sound classification, abnormal respiratory sound detection, abnormal respiratory sound classification, wheeze detection, wheeze classification, crackle detection, crackle classification, rhonchi detection, rhonchi classification, stridor detection, stridor classification, pleural rub detection, pleural rub classification, squawk detection, and squawk classification. Study selection Only articles were included that focused on adventitious sound detection or classification, based on respiratory sounds, with performance reported and sufficient information provided to be approximately repeated. Data extraction Investigators extracted data about the adventitious sound type analysed, approach and level of analysis, instrumentation or data source, location of sensor, amount of data obtained, data management, features, methods, and performance achieved. Data synthesis A total of 77 reports from the literature were included in this review. 55 (71.43%) of the studies focused on wheeze, 40 (51.95%) on crackle, 9 (11.69%) on stridor, 9 (11.69%) on rhonchi, and 18 (23.38%) on other sounds such as pleural rub, squawk, as well as the pathology. Instrumentation used to collect data included microphones, stethoscopes, and accelerometers. Several references obtained data from online repositories or book audio CD companions. Detection or classification methods used varied from empirically determined thresholds to more complex machine learning techniques. Performance reported in the surveyed works were converted to accuracy measures for data synthesis. Limitations Direct comparison of the performance of surveyed works cannot be performed as the input data used by each was different. A standard validation method has not been established, resulting in different works using different methods and performance measure definitions. Conclusion A review of the literature was performed to summarise different analysis approaches, features, and methods used for the analysis. The performance of recent studies showed a high agreement with conventional non-automatic identification. This suggests that automated adventitious sound detection or classification is a promising solution to overcome the limitations of conventional auscultation and to assist in the monitoring of relevant diseases.
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Affiliation(s)
| | - Stuart Bowyer
- Department of Electrical and Electronic Engineering, Imperial College London, London, United Kingdom
| | - Esther Rodriguez-Villegas
- Department of Electrical and Electronic Engineering, Imperial College London, London, United Kingdom
- * E-mail:
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11
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Li SH, Lin BS, Tsai CH, Yang CT, Lin BS. Design of Wearable Breathing Sound Monitoring System for Real-Time Wheeze Detection. SENSORS 2017; 17:s17010171. [PMID: 28106747 PMCID: PMC5298744 DOI: 10.3390/s17010171] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/13/2016] [Revised: 12/27/2016] [Accepted: 01/13/2017] [Indexed: 11/16/2022]
Abstract
In the clinic, the wheezing sound is usually considered as an indicator symptom to reflect the degree of airway obstruction. The auscultation approach is the most common way to diagnose wheezing sounds, but it subjectively depends on the experience of the physician. Several previous studies attempted to extract the features of breathing sounds to detect wheezing sounds automatically. However, there is still a lack of suitable monitoring systems for real-time wheeze detection in daily life. In this study, a wearable and wireless breathing sound monitoring system for real-time wheeze detection was proposed. Moreover, a breathing sounds analysis algorithm was designed to continuously extract and analyze the features of breathing sounds to provide the objectively quantitative information of breathing sounds to professional physicians. Here, normalized spectral integration (NSI) was also designed and applied in wheeze detection. The proposed algorithm required only short-term data of breathing sounds and lower computational complexity to perform real-time wheeze detection, and is suitable to be implemented in a commercial portable device, which contains relatively low computing power and memory. From the experimental results, the proposed system could provide good performance on wheeze detection exactly and might be a useful assisting tool for analysis of breathing sounds in clinical diagnosis.
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Affiliation(s)
- Shih-Hong Li
- Department of Thoracic Medicine, Chang Gung Memorial Hospital at Linkou, Taoyuan 33305, Taiwan.
- Department of Respiratory Therapy, College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan.
| | - Bor-Shing Lin
- Department of Computer Science and Information Engineering, National Taipei University, New Taipei City 23741, Taiwan.
| | - Chen-Han Tsai
- Institute of Imaging and Biomedical Photonics, National Chiao Tung University, Tainan 71150, Taiwan.
| | - Cheng-Ta Yang
- Department of Thoracic Medicine, Chang Gung Memorial Hospital at Taoyuan, Taoyuan 33378, Taiwan.
- Department of Respiratory Therapy, College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan.
| | - Bor-Shyh Lin
- Institute of Imaging and Biomedical Photonics, National Chiao Tung University, Tainan 71150, Taiwan.
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12
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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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Mineshita M, Kida H, Handa H, Nishine H, Furuya N, Inoue T, Matsuoka S, Miyazawa T. Regional Lung Sound Asynchrony in Chronic Obstructive Pulmonary Disease Patients. Respiration 2016; 92:252-257. [DOI: 10.1159/000449255] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Accepted: 08/17/2016] [Indexed: 11/19/2022] Open
Abstract
<b><i>Background:</i></b> Regional lung sound distribution in chronic obstructive pulmonary disease (COPD) is reported to be asynchronous. Mathematical analyses using vibration response imaging (VRI), such as left and right lung asynchrony (gap index; GI) and regional lung asynchrony (asynchrony score; AS), are useful measures to evaluate lung sound asynchrony. <b><i>Objectives:</i></b> The aim of this study was to investigate the association of lung sound asynchrony with pulmonary functions and emphysematous lesions in COPD patients. <b><i>Methods:</i></b> VRI recordings and pulmonary function tests were performed in 46 stable male COPD patients and in 40 healthy male smokers. Lung sound asynchrony was evaluated using GI, AS of the left and right lung (AS L-R), and AS of the upper and lower lung (AS U-L). In 38 patients, computed tomography taken within 6 months was available and analyzed. <b><i>Results:</i></b> AS L-R and AS U-L were significantly higher in COPD patients than in healthy smokers, with no significant difference in GI. There were no significant correlations with either AS and pulmonary functions, excluding a negative correlation between AS U-L and diffusion capacity. Although there were no significant correlations between both AS and severity of emphysema, significant positive correlations were observed between heterogeneity of emphysematous lesions and AS L-R (ρ = 0.38, p < 0.05) or AS U-L (ρ = 0.51, p < 0.005). <b><i>Conclusions:</i></b> Regional lung sounds are distributed more asynchronously in COPD patients than in healthy smokers, which correlates with the heterogeneous distribution of emphysematous lesions.
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Jiang H, Chen J, Cao J, Mu L, Hu Z, He J. Evaluation of Vibration Response Imaging (VRI) Technique and Difference in VRI Indices Among Non-Smokers, Active Smokers and Passive Smokers. Med Sci Monit 2015. [PMID: 26212715 PMCID: PMC4521697 DOI: 10.12659/msm.894335] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Background Vibration response imaging (VRI) is a new technology for lung imaging. Active smokers and non-smokers show differences in VRI findings, but no data are available for passive smokers. The aim of this study was to evaluate the use of VRI and to assess the differences in VRI findings among non-smokers, active smokers, and passive smokers. Material/Methods Healthy subjects (n=165: 63 non-smokers, 56 active smokers, and 46 passive smokers) with normal lung function were enrolled. Medical history, physical examination, lung function test, and VRI were performed for all subjects. Correlation between smoking index and VRI scores (VRIS) were performed. Results VRI images showed progressive and regressive stages representing the inspiratory and expiratory phases bilaterally in a vertical and synchronized manner in non-smokers. Vibration energy curves with low expiratory phase and plateau were present in 6.35% and 3.17%, respectively, of healthy non-smokers, 41.07% and 28.60% of smokers, and 39.13% and 30.43% of passive smokers, respectively. The massive energy peak in the non-smokers, smokers, and passive-smokers was 1.77±0.27, 1.57±0.29, and 1.66±0.33, respectively (all P<0.001). A weak but positive correlation was observed between VRIS and smoking index. Conclusions VRI can intuitively show the differences between non-smokers and smokers. VRI revealed that passive smoking can also harm the lungs. VRI could be used to visually persuade smokers to give up smoking.
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Affiliation(s)
- Hongying Jiang
- Department of Respiratory Medicine, Aerospace Center Hospital, Beijing, China (mainland)
| | - Jichao Chen
- Department of Respiratory Medicine, Aerospace Center Hospital, Beijing, China (mainland)
| | - Jinying Cao
- Department of Respiratory Medicine, Aerospace Center Hospital, Beijing, China (mainland)
| | - Lan Mu
- Department of Respiratory Medicine, Aerospace Center Hospital, Beijing, China (mainland)
| | - Zhenyu Hu
- Department of Respiratory Medicine, Aerospace Center Hospital, Beijing, China (mainland)
| | - Jian He
- Department of Respiratory Medicine, Aerospace Center Hospital, Beijing, China (mainland)
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Mansy HA, Balk RA, Warren WH, Royston TJ, Dai Z, Peng Y, Sandler RH. Pneumothorax effects on pulmonary acoustic transmission. J Appl Physiol (1985) 2015; 119:250-7. [PMID: 26023225 DOI: 10.1152/japplphysiol.00148.2015] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Accepted: 05/26/2015] [Indexed: 11/22/2022] Open
Abstract
Pneumothorax (PTX) is an abnormal accumulation of air between the lung and the chest wall. It is a relatively common and potentially life-threatening condition encountered in patients who are critically ill or have experienced trauma. Auscultatory signs of PTX include decreased breath sounds during the physical examination. The objective of this exploratory study was to investigate the changes in sound transmission in the thorax due to PTX in humans. Nineteen human subjects who underwent video-assisted thoracic surgery, during which lung collapse is a normal part of the surgery, participated in the study. After subjects were intubated and mechanically ventilated, sounds were introduced into their airways via an endotracheal tube. Sounds were then measured over the chest surface before and after lung collapse. PTX caused small changes in acoustic transmission for frequencies below 400 Hz. A larger decrease in sound transmission was observed from 400 to 600 Hz, possibly due to the stronger acoustic transmission blocking of the pleural air. At frequencies above 1 kHz, the sound waves became weaker and so did their changes with PTX. The study elucidated some of the possible mechanisms of sound propagation changes with PTX. Sound transmission measurement was able to distinguish between baseline and PTX states in this small patient group. Future studies are needed to evaluate this technique in a wider population.
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Affiliation(s)
- Hansen A Mansy
- Department of Mechanical and Aerospace Engineering and Department of Pediatrics, University of Central Florida, Orlando, Florida;
| | - Robert A Balk
- Division of Pulmonary and Critical Care Medicine, Rush Medical College, Chicago, Illinois
| | - William H Warren
- Department of Cardiovascular-Thoracic Surgery, Rush Medical College, Chicago, Illinois
| | - Thomas J Royston
- Department of Bioengineering, University of Illinois at Chicago, Chicago, Illinois; and
| | - Zoujun Dai
- Department of Mechanical Engineering, University of Illinois at Chicago, Chicago, Illinois
| | - Ying Peng
- Department of Mechanical Engineering, University of Illinois at Chicago, Chicago, Illinois
| | - Richard H Sandler
- Department of Mechanical and Aerospace Engineering and Department of Pediatrics, University of Central Florida, Orlando, Florida
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Dai Z, Peng Y, Mansy HA, Sandler RH, Royston TJ. Experimental and Computational Studies of Sound Transmission in a Branching Airway Network Embedded in a Compliant Viscoelastic Medium. JOURNAL OF SOUND AND VIBRATION 2015; 339:215-229. [PMID: 26097256 PMCID: PMC4469198 DOI: 10.1016/j.jsv.2014.11.026] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Breath sounds are often used to aid in the diagnosis of pulmonary disease. Mechanical and numerical models could be used to enhance our understanding of relevant sound transmission phenomena. Sound transmission in an airway mimicking phantom was investigated using a mechanical model with a branching airway network embedded in a compliant viscoelastic medium. The Horsfield self-consistent model for the bronchial tree was adopted to topologically couple the individual airway segments into the branching airway network. The acoustics of the bifurcating airway segments were measured by microphones and calculated analytically. Airway phantom surface motion was measured using scanning laser Doppler vibrometry. Finite element simulations of sound transmission in the airway phantom were performed. Good agreement was achieved between experiments and simulations. The validated computational approach can provide insight into sound transmission simulations in real lungs.
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Affiliation(s)
- Zoujun Dai
- University of Illinois at Chicago, Chicago, IL 60607, USA
- Corresponding author.
| | - Ying Peng
- University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Hansen A. Mansy
- University of Central Florida, Orlando, FL 32816, USA
- Rush University Medical Center, Chicago, IL 60612, USA
| | - Richard H. Sandler
- University of Central Florida, Orlando, FL 32816, USA
- Nemours Children’s Hospital, Orlando, FL 32827, USA
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Dai Z, Peng Y, Mansy HA, Sandler RH, Royston TJ. Comparison of Poroviscoelastic Models for Sound and Vibration in the Lungs. JOURNAL OF VIBRATION AND ACOUSTICS 2014; 136:0510121-5101211. [PMID: 25278740 PMCID: PMC4112928 DOI: 10.1115/1.4026436] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Revised: 12/18/2013] [Indexed: 05/23/2023]
Abstract
Noninvasive measurement of mechanical wave motion (sound and vibration) in the lungs may be of diagnostic value, as it can provide information about the mechanical properties of the lungs, which in turn are affected by disease and injury. In this study, two previously derived theoretical models of the vibroacoustic behavior of the lung parenchyma are compared: (1) a Biot theory of poroviscoelasticity and (2) an effective medium theory for compression wave behavior (also known as a "bubble swarm" model). A fractional derivative formulation of shear viscoelasticity is integrated into both models. A measurable "fast" compression wave speed predicted by the Biot theory formulation has a significant frequency dependence that is not predicted by the effective medium theory. Biot theory also predicts a slow compression wave. The experimentally measured fast compression wave speed and attenuation in a pig lung ex vivo model agreed well with the Biot theory. To obtain the parameters for the Biot theory prediction, the following experiments were undertaken: quasistatic mechanical indentation measurements were performed to estimate the lung static shear modulus; surface wave measurements were performed to estimate lung tissue shear viscoelasticity; and flow permeability was measured on dried lung specimens. This study suggests that the Biot theory may provide a more robust and accurate model than the effective medium theory for wave propagation in the lungs over a wider frequency range.
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Affiliation(s)
- Zoujun Dai
- University of Illinois at Chicago , Chicago, IL 60607
| | - Ying Peng
- University of Illinois at Chicago , Chicago, IL 60607
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Mineshita M, Kida H, Handa H, Nishine H, Furuya N, Nobuyama S, Inoue T, Matsuoka S, Miyazawa T. The correlation between lung sound distribution and pulmonary function in COPD patients. PLoS One 2014; 9:e107506. [PMID: 25244247 PMCID: PMC4171498 DOI: 10.1371/journal.pone.0107506] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Accepted: 08/12/2014] [Indexed: 11/18/2022] Open
Abstract
Background Regional lung sound intensity in chronic obstructive pulmonary disease (COPD) patients is influenced by the severity and distribution of emphysema, obstructed peripheral airways, and altered ribcage and diaphragm configurations and movements due to hyperinflation. Changes in the lung sound distribution accompanied by pulmonary function improvements in COPD patients were observed after bronchodilator inhalation. We investigated the association of lung sound distribution with pulmonary functions, and the effects of emphysematous lesions on this association. These studies were designed to acquire the basic knowledge necessary for the application of lung sound analysis in the physiological evaluation of COPD patients. Methods Pulmonary function tests and the percentage of upper- and lower-lung sound intensity (quantitative lung data [QLD]) were evaluated in 47 stable male COPD patients (54 - 82 years of age). In 39 patients, computed tomography taken within 6 months of the study was available and analyzed. Results The ratio of lower QLD to upper QLD showed significant positive correlations with FEV1 %predicted (%FEV1; ρ = 0.45, p<0.005) and MEF50 %predicted (%MEF50; ρ = 0.46, p<0.005). These correlations were not observed in COPD patients with dominant emphysema (% low attenuation area >40%, n = 20) and were stronger in less emphysematous patients (n = 19, %FEV1; ρ = 0.64, p<0.005, %MEF50; ρ = 0.71, p<0.001). Conclusions In COPD patients, the ratio of lower- to upper-lung sound intensities decreased according to the severity of obstructive changes, although emphysematous lesions considerably affected lung sound distribution.
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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
- * E-mail:
| | - Hirotaka Kida
- 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
| | - Hiroki Nishine
- 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
| | - 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
| | - Shin Matsuoka
- Department of Radiology, 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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Mineshita M, Kida H, Nishine H, Handa H, Inoue T, Miyazawa T. Left and right lung asynchrony as a physiological indicator for unilateral bronchial obstruction in interventional bronchoscopy. PLoS One 2014; 9:e105327. [PMID: 25133760 PMCID: PMC4136828 DOI: 10.1371/journal.pone.0105327] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Accepted: 07/17/2014] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND In patients with bronchial obstruction, pulmonary function tests may not change significantly after intervention. The airflow asynchrony in both lungs due to unilateral bronchial obstruction may be applicable as a physiological indicator. The airflow asynchrony is reflected by the difference in the left and right lung sound development at tidal breathing. OBJECTIVES To investigate the usefulness of left and right lung asynchrony due to unilateral bronchial obstruction as a physiological indicator for interventional bronchoscopy. METHODS Fifty cases with central airway obstruction were classified into three groups: tracheal, bronchial and extensive obstruction. The gap index was defined as the absolute value of the average of gaps between the left and right lung sound intensity peaks for a 12-second duration. RESULTS Before interventional bronchoscopy, the gap index was significantly higher in the bronchial (p<0.05) and extensive obstruction groups (p<0.05) than in the tracheal group. The gap index in cases with unilateral bronchial obstruction of at least 80% (0.18±0.04 seconds) was significantly higher than in cases with less than 80% obstruction (0.02±0.01 seconds, p<0.05). After intervention for bronchial obstruction, the dyspnea scale (p<0.001) and gap index significantly improved (p<0.05), although no significant improvements were found in spirometric assessments. The responder rates for dyspnea were 79.3% for gap indexes over 0.06 seconds and 55.6% for gap indexes of 0.06 seconds or under. CONCLUSIONS Assessment of left and right lung asynchrony in central airway obstruction with bronchial involvement may provide useful physiological information for interventional bronchoscopy.
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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, Kanagawa, Japan
- * E-mail:
| | - Hirotaka Kida
- Division of Respiratory and Infectious Diseases, Department of Internal Medicine, St. Marianna University School of Medicine, Kawasaki, Kanagawa, Japan
| | - Hiroki Nishine
- Division of Respiratory and Infectious Diseases, Department of Internal Medicine, St. Marianna University School of Medicine, Kawasaki, Kanagawa, Japan
| | - Hiroshi Handa
- Division of Respiratory and Infectious Diseases, Department of Internal Medicine, St. Marianna University School of Medicine, Kawasaki, Kanagawa, Japan
| | - Takeo Inoue
- Division of Respiratory and Infectious Diseases, Department of Internal Medicine, St. Marianna University School of Medicine, Kawasaki, Kanagawa, Japan
| | - Teruomi Miyazawa
- Division of Respiratory and Infectious Diseases, Department of Internal Medicine, St. Marianna University School of Medicine, Kawasaki, Kanagawa, Japan
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Pesin J, Faingersh A, Waisman D, Landesberg A. Highly sensitive monitoring of chest wall dynamics and acoustics provides diverse valuable information for evaluating ventilation and diagnosing pneumothorax. J Appl Physiol (1985) 2014; 116:1632-40. [DOI: 10.1152/japplphysiol.00966.2013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Current practice of monitoring lung ventilation in neonatal intensive care units, utilizing endotracheal tube pressure and flow, end-tidal CO2, arterial O2 saturation from pulse oximetry, and hemodynamic indexes, fails to account for asymmetric pathologies and to allow for early detection of deteriorating ventilation. This study investigated the utility of bilateral measurements of chest wall dynamics and sounds, in providing early detection of changes in the mechanics and distribution of lung ventilation. Nine healthy New Zealand rabbits were ventilated at a constant pressure, while miniature accelerometers were attached to each side of the chest. Slowly progressing pneumothorax was induced by injecting 1 ml/min air into the pleural space on either side of the chest. The end of the experiment ( tPTX) was defined when arterial O2 saturation from pulse oximetry dropped <90% or when vigorous spontaneous breathing began, since it represents the time of clinical detection using common methods. Consistent and significant changes were observed in 15 of the chest dynamics parameters. The most meaningful temporal changes were noted for features extracted from subsonic dynamics (<10 Hz), e.g., tidal amplitude, energy, and autoregressive poles. Features from the high-frequency band (10–200 Hz), e.g., energy and entropy, exhibited smaller but significant changes. At 70% tPTX, identification of asymmetric ventilation was attained for all animals. Side identification of the pneumothorax was achieved at 50% tPTX, within a 95% confidence interval. Diagnosis was, on average, 34.1 ± 18.8 min before tPTX. In conclusion, bilateral monitoring of the chest dynamics and acoustics provide novel information that is sensitive to asymmetric changes in ventilation, enabling early detection and localization of pneumothorax.
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Affiliation(s)
- Jimy Pesin
- Faculty of Biomedical Engineering, Technion, Israel Institute of Technology, Haifa, Israel
| | - Anna Faingersh
- Faculty of Biomedical Engineering, Technion, Israel Institute of Technology, Haifa, Israel
| | - Dan Waisman
- Faculty of Biomedical Engineering, Technion, Israel Institute of Technology, Haifa, Israel
- Department of Neonatology, Carmel Medical Center, and Faculty of Medicine, Technion, Haifa, Israel
| | - Amir Landesberg
- Faculty of Biomedical Engineering, Technion, Israel Institute of Technology, Haifa, Israel
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Detecting unilateral phrenic paralysis by acoustic respiratory analysis. PLoS One 2014; 9:e93595. [PMID: 24718599 PMCID: PMC3981712 DOI: 10.1371/journal.pone.0093595] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2013] [Accepted: 03/07/2014] [Indexed: 12/11/2022] Open
Abstract
The consequences of phrenic nerve paralysis vary from a considerable reduction in respiratory function to an apparently normal state. Acoustic analysis of lung sound intensity (LSI) could be an indirect non-invasive measurement of respiratory muscle function, comparing activity on the two sides of the thoracic cage. Lung sounds and airflow were recorded in ten males with unilateral phrenic paralysis and ten healthy subjects (5 men/5 women), during progressive increasing airflow maneuvers. Subjects were in sitting position and two acoustic sensors were placed on their back, on the left and right sides. LSI was determined from 1.2 to 2.4 L/s between 70 and 2000 Hz. LSI was significantly greater on the normal (19.3±4.0 dB) than the affected (5.7±3.5 dB) side in all patients (p = 0.0002), differences ranging from 9.9 to 21.3 dB (13.5±3.5 dB). In the healthy subjects, the LSI was similar on both left (15.1±6.3 dB) and right (17.4±5.7 dB) sides (p = 0.2730), differences ranging from 0.4 to 4.6 dB (2.3±1.6 dB). There was a positive linear relationship between the LSI and the airflow, with clear differences between the slope of patients (about 5 dB/L/s) and healthy subjects (about 10 dB/L/s). Furthermore, the LSI from the affected side of patients was close to the background noise level, at low airflows. As the airflow increases, the LSI from the affected side did also increase, but never reached the levels seen in healthy subjects. Moreover, the difference in LSI between healthy and paralyzed sides was higher in patients with lower FEV1 (%). The acoustic analysis of LSI is a relevant non-invasive technique to assess respiratory function. This method could reinforce the reliability of the diagnosis of unilateral phrenic paralysis, as well as the monitoring of these patients.
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Assessing the variability in respiratory acoustic thoracic imaging (RATHI). Comput Biol Med 2014; 45:58-66. [DOI: 10.1016/j.compbiomed.2013.11.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2012] [Revised: 11/07/2013] [Accepted: 11/18/2013] [Indexed: 11/19/2022]
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Assessment of regional ventilation distribution: comparison of vibration response imaging (VRI) with electrical impedance tomography (EIT). PLoS One 2014; 9:e86638. [PMID: 24475160 PMCID: PMC3903564 DOI: 10.1371/journal.pone.0086638] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2013] [Accepted: 12/11/2013] [Indexed: 11/21/2022] Open
Abstract
Background Vibration response imaging (VRI) is a bedside technology to monitor ventilation by detecting lung sound vibrations. It is currently unknown whether VRI is able to accurately monitor the local distribution of ventilation within the lungs. We therefore compared VRI to electrical impedance tomography (EIT), an established technique used for the assessment of regional ventilation. Methodology/Principal Findings Simultaneous EIT and VRI measurements were performed in the healthy and injured lungs (ALI; induced by saline lavage) at different PEEP levels (0, 5, 10, 15 mbar) in nine piglets. Vibration energy amplitude (VEA) by VRI, and amplitudes of relative impedance changes (rel.ΔZ) by EIT, were evaluated in seven regions of interest (ROIs). To assess the distribution of tidal volume (VT) by VRI and EIT, absolute values were normalized to the VT obtained by simultaneous spirometry measurements. Redistribution of ventilation by ALI and PEEP was detected by VRI and EIT. The linear correlation between pooled VT by VEA and rel.ΔZ was R2 = 0.96. Bland-Altman analysis showed a bias of −1.07±24.71 ml and limits of agreement of −49.05 to +47.36 ml. Within the different ROIs, correlations of VT-distribution by EIT and VRI ranged between R2 values of 0.29 and 0.96. ALI and PEEP did not alter the agreement of VT between VRI and EIT. Conclusions/Significance Measurements of regional ventilation distribution by VRI are comparable to those obtained by EIT.
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Mineshita M, Matsuoka S, Miyazawa T. Effects of Bronchodilators on Regional Lung Sound Distribution in Patients with Chronic Obstructive Pulmonary Disease. Respiration 2014; 87:45-53. [DOI: 10.1159/000350228] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2012] [Accepted: 02/06/2013] [Indexed: 11/19/2022] Open
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Abstract
BACKGROUND The concept of lung sounds conveying information regarding lung physiology has been used extensively in clinical practice, particularly with physical auscultation using a stethoscope. Advances in computer technology have facilitated the construction of dynamic visual images derived from recorded lung sounds. Arguably, the most significant progress in this field was the development of the commercially available vibration response imaging (VRI) (Deep Breeze Ltd, Or-Akiva, Israel). This device provides a non-invasive, dynamic image of both lungs constructed from sounds detected from the lungs using surface sensors. In the literature, VRI has been utilized in a multitude of clinical and research settings. This systematic review aims to address three study questions relating to whether VRI can be used as an evaluative device, whether the images generated can be characterized, and which tools and measures have been used to assess these images. METHODS/DESIGN This systematic review will involve implementing search strategies in five online journal databases in order to extract articles relating to the application of VRI. Appropriate articles will be identified against a set of pre-determined eligibility criteria and assessed for methodological quality using a standardized scale. Included articles will have data extracted by the reviewers using a standardized evidence table. A narrative synthesis based on a standardized framework will be conducted, clustering evidence into three main groups; one for each of the study questions. A meta-analysis will be conducted if two or more research articles meet pre-determined criteria that allow quantitative synthesis to take place. DISCUSSION This systematic review aims to provide a complete overview of the scope of VRI in the clinical and research settings, as well as to discuss methods to interpret the data obtained from VRI. The systematic review intends to help clinicians to make informed decisions on the clinical applicability of the device, to allow researchers to identify further potential avenues of investigation, and to provide methods for the evaluation and interpretation of dynamic and static images. The publication and registration of this review with PROSPERO provides transparency and accountability, and facilitates the appraisal of the proposed systematic review against the original design. TRIAL REGISTRATION PROSPERO registration number: CRD42013003751.
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A new method to predict values for postoperative lung function and surgical risk of lung resection by quantitative breath sound measurements. Am J Clin Oncol 2013; 36:273-8. [PMID: 22547008 DOI: 10.1097/coc.0b013e3182467fdc] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES We evaluated quantitative acoustic measurements, as a simpler alternative to perfusion scintigraphy, for estimation of predicted postoperative (ppo) lung function after resection surgery in our patient population. METHODS Patients with lung cancer, considered as candidates for lung resection, were enrolled in the study. All patients underwent lung function testing and quantitative breath sound testing by vibration response imaging (VRI) on the same day. A subset of patients also had perfusion testing. Forced expiratory volume in 1 second (FEV(1)) and diffusing capacity of the lung for carbon monoxide (DLCO) predictions derived from VRI testing were compared with perfusion values and actual FEV(1) values at 1 month postoperatively. RESULTS Fifty-three subjects (40 males; age 66±8 y) participated. There was high correlation between both methods for the calculation of ppoFEV(1)% (R=0.94; n=39) and ppoFEV (L) (R=0.90; n=39). PpoFEV(1) were 58±18% versus 56±20% and 1.69±0.49 L versus 1.62±0.52 L, based on perfusion and VRI methods, respectively. In 92% (36/39) of calculations, the difference between the 2 methods was <10%. High correlations also existed between VRI and perfusion for the calculation of ppoDLCO% (R=0.95; n=37) and ppoDLCO mL/min/mm Hg (R=0.90; n=37). VRI predictions showed good correlation for the 34 patients with actual postoperative lung function (R=0.88 and R=0.80 for FEV(1)% and FEV(1)L, respectively). Accuracy of the VRI to predict surgical risk (<40% cutoff threshold for ppo values) compared with actual postoperative values was 85% (29/34). CONCLUSIONS Predictions of postoperative lung function using VRI agree well with radionuclide techniques and actual measured postoperative values. VRI may provide a noninvasive, simpler alternative for estimation of ppo values, particularly when perfusion testing is not readily available.
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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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Slattery DE, Pollack CV. Vibration response imaging of lung function in acute asthma in the Emergency Department. J Emerg Med 2013; 44:987-8. [PMID: 23490114 DOI: 10.1016/j.jemermed.2012.01.070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2010] [Revised: 01/26/2011] [Accepted: 01/17/2012] [Indexed: 10/27/2022]
Affiliation(s)
- David E Slattery
- Department of Emergency Medicine, University of Nevada School of Medicine, University Medical Center of Southern Nevada, Las Vegas, Nevada, USA
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Detterbeck F, Gat M, Miller D, Force S, Chin C, Fernando H, Sonett J, Morice R. A New Method to Predict Postoperative Lung Function: Quantitative Breath Sound Measurements. Ann Thorac Surg 2013; 95:968-75. [DOI: 10.1016/j.athoracsur.2012.07.045] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2012] [Revised: 07/18/2012] [Accepted: 07/23/2012] [Indexed: 10/27/2022]
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Kim HK, Yoo D, Sung HK, Lee HJ, Choi YH. Vibration response imaging in prediction of pulmonary function after pulmonary resection. Ann Thorac Surg 2012; 94:1680-6. [PMID: 22959575 DOI: 10.1016/j.athoracsur.2012.07.019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2012] [Revised: 07/09/2012] [Accepted: 07/11/2012] [Indexed: 10/27/2022]
Abstract
BACKGROUND Vibration response imaging (VRI) is a new technique that captures lung sounds generated by the flow of air through the lungs. It predicts postoperative values for an intended lung resection. In this study, we measured the predicted postoperative pulmonary function as determined by a perfusion lung scan and the VRI, and compared with results from the postoperative pulmonary function. METHODS This study was performed prospectively in patients who were candidates for major pulmonary resection. Each patient underwent a pulmonary function test, perfusion scintigraphy, and VRI within 1 week before operation. Postoperative lung function was measured at 4 to 6 weeks. RESULTS The study enrolled 44 patients. There were no significant differences for predicted postoperative forced expiratory volume in 1 second (ppoFEV(1)) and predicted postoperative diffusion capacity of the lung for carbon monoxide (ppoDlco) between scan and VRI. Both ppoFEV(1) and ppoDlco using a scan and VRI predicted the postoperative results well, respectively. The postoperative FEV(1) was correlated with ppoFEV(1) using a scan (r = 0.83, p < 0.001), and the ppoFEV(1) using a VRI (r = 0.83, p < 0.001). The postoperative Dlco was correlated with the ppoDlco using a scan (r = 0.85, p < 0.001), and the ppoDlco using a VRI (r = 0.80, p < 0.001). CONCLUSIONS The VRI was highly predictive of postoperative FEV(1) and Dlco for lung resection.
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Affiliation(s)
- Hyun Koo Kim
- Department of Thoracic and Cardiovascular Surgery, Korea University Guro Hospital, Korea University College of Medicine, Seoul, Korea.
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Radzievsky N, Papyan S, Kushnir I, Gat M, Kushnir A, Sagie A, Agmon Y. Estimation of left ventricular function using a novel acoustic-based device. Eur J Clin Invest 2012; 42:402-10. [PMID: 21950619 DOI: 10.1111/j.1365-2362.2011.02596.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND We examined the feasibility of estimating left ventricular ejection fraction (LVEF) by a novel acoustic-based device [vibration response imaging (VRI); Deep Breeze]. METHODS One hundred and forty-one subjects (117 patients and 24 healthy volunteers; age 55 ± 15 years, 82% men) were examined by both VRI and echocardiography. LVEF was determined by echocardiography (echo-LVEF) using the biplane Simpson's method. Low-frequency acoustic signals (10-70 Hz) were recorded by VRI from the left posterior thorax by a matrix of 36 microphones during 8 s of breath holding, and an electrocardiogram was recorded simultaneously. The acoustic signals were processed digitally, and an algorithm designed to estimate LVEF was developed (VRI-LVEF), based on a combination of multiple acoustic (systolic and diastolic acoustic signals, beat-to-beat variability of acoustic signals and propagation of acoustic signals throughout the matrix), electrocardiographic and clinical parameters. RESULTS Mean echo-LVEF was 51 ± 15% (range, 11-76%). Echo-LVEF was reduced (< 50%) in 55 subjects (39%) and severely reduced (< 35%) in 28 subjects (20%). VRI-LVEF calculated by a multivariate algorithm correlated significantly with echo-LVEF (R(2) = 0·59; P < 0·001). VRI-LVEF accurately predicted the presence of reduced (< 50%) or severely reduced (< 35%) echo-LVEF, with sensitivities of 84% and 82%, specificities of 86% and 91%, positive predictive values of 79% and 70% and negative predictive values of 89% and 95%, respectively. CONCLUSIONS LVEF can be estimated using a novel acoustic-based device. This device may assist in triage of patients according to LVEF prior to definitive assessment of LVEF by echocardiography.
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Computerised lung sound monitoring to assess effectiveness of chest physiotherapy and secretion removal: a feasibility study. Physiotherapy 2012; 98:250-5. [PMID: 22898583 DOI: 10.1016/j.physio.2011.12.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2011] [Accepted: 12/14/2011] [Indexed: 11/22/2022]
Abstract
OBJECTIVES To explore the feasibility of computerised lung sound monitoring to evaluate secretion removal in intubated and mechanically ventilated adult patients. DESIGN Before and after observational investigation. SETTING Intensive care unit. PARTICIPANTS Fifteen intubated and mechanically ventilated adult patients receiving chest physiotherapy. INTERVENTIONS Chest physiotherapy included combinations of standard closed airway suctioning, saline lavage, postural drainage, chest wall vibrations, manual-assisted cough and/or lung hyperinflation, dependent upon clinical indications. MAIN OUTCOME MEASURES Lung sound amplitude at peak inspiration was assessed using computerised lung sound monitoring. Measurements were performed immediately before and after chest physiotherapy. Data are reported as mean [standard deviation (SD)], mean difference and 95% confidence intervals (CI). Significance testing was not performed due to the small sample size and the exploratory nature of the study. RESULTS Fifteen patients were included in the study [11 males, four females, mean age 65 (SD 14) years]. The mean total lung sound amplitude at peak inspiration decreased two-fold from 38 (SD 59) units before treatment to 17 (SD 19) units after treatment (mean difference 22, 95% CI of difference -3 to 46). The mean total lung sound amplitude from the lungs of patients with a large amount of secretions (n=9) was over four times 'louder' than the lungs of patients with a moderate or small amount of secretions (n=6) [56 (SD 72) units vs 12 (13) units, respectively; mean difference -44, 95% CI of difference -100 to 11]. The mean total lung sound amplitude decreased in the group of 'loud' right and left lungs (n=15) from 37 (SD 36) units before treatment to 15 (SD 13) units after treatment (mean difference 22, 95% CI of difference 6 to 38). CONCLUSION Computerised lung sound monitoring in this small group of patients demonstrated a two-fold decrease in lung sound amplitude following chest physiotherapy. Subgroup analysis also demonstrated decreasing trends in lung sound amplitude in the group of 'loud' lungs following chest physiotherapy. Due to the small sample size and large SDs with high variability in the lung sound amplitude measurements, significance testing was not reported. Further investigation is needed in a larger sample of patients with more accurate measurement of sputum wet weight in order to distinguish between secretion-related effects and changes due to other factors such as airflow rate and pattern.
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Wang Z, Xiong YX. Lung sound patterns help to distinguish congestive heart failure, chronic obstructive pulmonary disease, and asthma exacerbations. Acad Emerg Med 2012; 19:79-84. [PMID: 22251194 DOI: 10.1111/j.1553-2712.2011.01255.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Abstract
OBJECTIVES Although congestive heart failure (CHF), chronic obstructive pulmonary disease (COPD), and asthma patients typically present with abnormal auscultatory findings on lung examination, respiratory sounds are not normally subjected to rigorous analysis. The aim of this study was to evaluate in detail the distribution of respiratory sound intensity in CHF, COPD, and asthma patients during acute exacerbation. METHODS Respiratory sounds throughout the respiratory cycle were captured and displayed using an acoustic-based imaging technique. Breath sound distribution was mapped to create a gray-scale sequence of two-dimensional images based on intensity of sound (vibration). Consecutive CHF (n = 22), COPD (n = 19), and asthma (n = 18) patients were imaged at the time of presentation to the emergency department (ED). Twenty healthy subjects were also enrolled as a comparison group. Geographical area of the images and respiratory sound patterns were quantitatively analyzed. RESULTS In healthy volunteers and COPD patients, the median (interquartile range [IQR]) geographical areas of the vibration energy images were similar, at 75.6 (IQR = 6.0) and 75.8 (IQR = 10.8) kilopixels, respectively (p > 0.05). Compared to healthy volunteers and COPD patients, areas for CHF and asthma patients were smaller, at 66.9 (IQR = 9.9) and 53.9 (IQR = 15.6) kilopixels, respectively (p < 0.05). The geographic area ratios between the left and right lungs for healthy volunteers and CHF and COPD patients were 1.0 (IQR = 0.2), 1.0 (IQR = 0.2), and 1.0 (IQR = 0.1), respectively. Compared to healthy volunteers, the geographic area ratio between the left and right lungs for asthma patients was 0.5 (IQR = 0.4; p < 0.05). In healthy volunteers and CHF patients, the ratios of vibration energy values at peak inspiration and expiration (peak I/E ratio) were 4.6 (IQR = 4.4) and 4.7 (IQR = 3.5). In marked contrast, the peak I/E ratios of COPD and asthma patients were 3.4 (= 2.1) and 0.1 (IQR = 0.3; p < 0.05), respectively. CONCLUSIONS The pilot data generated in this study support the concept that relative differences in respiratory sound intensity may be useful in distinguishing acute dyspnea caused by CHF, COPD, or asthma.
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Affiliation(s)
- Zhen Wang
- Department of Emergency Medicine, Beijing Shi-ji-tan Hospital, Capital Medical University, Beijing, China.
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Rees SE. The Intelligent Ventilator (INVENT) project: the role of mathematical models in translating physiological knowledge into clinical practice. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2011; 104 Suppl 1:S1-S29. [PMID: 22152752 DOI: 10.1016/s0169-2607(11)00307-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
This dissertation has addressed the broad hypothesis as to whether building mathematical models is useful as a tool for translating physiological knowledge into clinical practice. In doing so it describes work on the INtelligent VENTilator project (INVENT), the goal of which is to build, evaluate and integrate into clinical practice, a model-based decision support system for control of mechanical ventilation. The dissertation describes the mathematical models included in INVENT, i.e. a model of pulmonary gas exchange focusing on oxygen transport, and a model of the acid-base status of blood, interstitial fluid and tissues. These models have been validated, and applied in two other systems: ALPE, a system for measuring pulmonary gas exchange and ARTY, a system for arterialisation of the acid-base and oxygen status of peripheral venous blood. The major contributions of this work are as follows. A mathematical model has been developed which can describe pulmonary gas exchange more accurately that current clinical techniques. This model is parsimonious in that it can describe pulmonary gas exchange from measurements easily available in the clinic, along with a readily automatable variation in F(I)O(2). This technique and model have been developed into a research and commercial tool (ALPE), and evaluated both in the clinical setting and when compared to the reference multiple inert gas elimination technique (MIGET). Mathematical models have been developed of the acid- base chemistry of blood, interstitial fluid and tissues, with these models formulated using a mass-action mass-balance approach. The model of blood has been validated against literature data describing the addition and removal of CO(2), strong acid or base, and haemoglobin; and the effects of oxygenation or deoxygenation. The model has also been validated in new studies, and shown to simulate accurately and precisely the mixing of blood samples at different PCO(2) and PO(2) levels. This model of acid-base chemistry of blood has been applied in the ARTY system. ARTY has been shown to accurately and precisely calculate arterial values of acid-base and oxygen status in patients residing in the ICU, and in those with chronic lung disease. The INtelligent VENTilator (INVENT) system has been developed for optimization of mechanical ventilator settings using physiological models and utility/penalty functions, separating physiological knowledge from clinical preference. The models can be tuned to the individual patient via parameter estimation, providing patient specific advice. The INVENT team has shown prospectively that the system provides advice on F(I)O(2) which is as good as clinical practice, and retrospectively that the system provides reasonable suggestions of tidal volume, respiratory frequency and F(I)O(2). In general, this dissertation has illustrated a further example of the role of modeling in describing and understanding complex systems. The dissertation has shown that when dealing with complexity the goal of the model must be in focus if a correct balance is to be maintained between system complexity and model parameterization. The original goal of the INVENT team, i.e. to build, evaluate and integrate a DSS for control of mechanical ventilation has not as yet been completed. However, the broader hypothesis that building models generates new and interesting questions has been successfully demonstrated. The ALPE model and system has been applied in intensive care, post operative care and cardiology and is currently being evaluated in new clinical domains. ARTY has been shown to have potential benefit in eliminating the need for painful arterial punctures, and may also be useful as a screening tool. These systems illustrate the benefits of investing in models as a mechanism for translating physiological knowledge to clinical practice.
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Affiliation(s)
- Stephen E Rees
- Center for Model-based Medical Decision Support, Department of Health Science and Technology, Aalborg University, Denmark
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SHARIF DAWOD, RADZIEVSKY NAIRA, SAMNIAH NEMER, HASSAN AMIN, KUSHNIR ALON, ROSENSCHEIN URI. Palpography Detects Mechanical Dyssynchrony and Worsens with Right Ventricular Pacing and Reduced Left Ventricular Ejection Fraction. Pacing Clin Electrophysiol 2011; 34:875-83. [DOI: 10.1111/j.1540-8159.2011.03057.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Park E, Park JH, Hong MJ, Kim WD, Lee KY, Kim SJ, Kim HJ, Ha KW, Chon GR, Kim HA, Yoo KH. Usefulness of Vibration Response Imaging (VRI) for Pneumonia Patients. Tuberc Respir Dis (Seoul) 2011. [DOI: 10.4046/trd.2011.71.1.30] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Affiliation(s)
- Eugene Park
- Department of Internal Medicine, Konkuk University School of Medicine, Seoul, Korea
| | - Jung Hee Park
- Department of Internal Medicine, Konkuk University School of Medicine, Seoul, Korea
| | - Mi-Jin Hong
- Department of Internal Medicine, Konkuk University School of Medicine, Seoul, Korea
| | - Won Dong Kim
- Department of Internal Medicine, Konkuk University School of Medicine, Seoul, Korea
| | - Kye Young Lee
- Department of Internal Medicine, Konkuk University School of Medicine, Seoul, Korea
| | - Sun Jong Kim
- Department of Internal Medicine, Konkuk University School of Medicine, Seoul, Korea
| | - Hee Joung Kim
- Department of Internal Medicine, Konkuk University School of Medicine, Seoul, Korea
| | - Kyoung-Won Ha
- Department of Internal Medicine, Konkuk University Chungju Hospital, Chungju, Korea
| | - Gyu Rak Chon
- Department of Internal Medicine, Konkuk University Chungju Hospital, Chungju, Korea
| | - Hyun Ai Kim
- Department of Internal Medicine, Konkuk University School of Medicine, Seoul, Korea
| | - Kwang Ha Yoo
- Department of Internal Medicine, Konkuk University School of Medicine, Seoul, Korea
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Morice RC, Jimenez CA, Eapen GA, Mehran RJ, Keus L, Ost D. Using quantitative breath sound measurements to predict lung function following resection. J Cardiothorac Surg 2010; 5:81. [PMID: 20939900 PMCID: PMC2964689 DOI: 10.1186/1749-8090-5-81] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2010] [Accepted: 10/12/2010] [Indexed: 02/03/2023] Open
Abstract
BACKGROUND Predicting postoperative lung function is important for estimating the risk of complications and long-term disability after pulmonary resection. We investigated the capability of vibration response imaging (VRI) as an alternative to lung scintigraphy for prediction of postoperative lung function in patients with intrathoracic malignancies. METHODS Eighty-five patients with intrathoracic malignancies, considered candidates for lung resection, were prospectively studied. The projected postoperative (ppo) lung function was calculated using: perfusion scintigraphy, ventilation scintigraphy, and VRI. Two sets of assessments made: one for lobectomy and one for pneumonectomy. Clinical concordance was defined as both methods agreeing that either a patient was or was not a surgical candidate based on a ppoFEV1% and ppoDLCO% > 40%. RESULTS Limits of agreement between scintigraphy and VRI for ppo following lobectomy were -16.47% to 15.08% (mean difference = -0.70%;95%CI = -2.51% to 1.12%) and for pneumonectomy were -23.79% to 19.04% (mean difference = -2.38%;95%CI = -4.69% to -0.07%). Clinical concordance between VRI and scintigraphy was 73% for pneumonectomy and 98% for lobectomy. For patients who had surgery and postoperative lung function testing (n = 31), ppoFEV1% using scintigraphic methods correlated with measured postoperative values better than projections using VRI, (adjusted R2 = 0.32 scintigraphy; 0.20 VRI), however the difference between methods failed to reach statistical significance. Limits of agreement between measured FEV1% postoperatively and ppoFEV1% based on perfusion scintigraphy were -16.86% to 23.73% (mean difference = 3.44%;95%CI = -0.29% to 7.16%); based on VRI were -19.56% to 28.99% (mean difference = 4.72%;95%CI = 0.27% to 9.17%). CONCLUSIONS Further investigation of VRI as an alternative to lung scintigraphy for prediction of postoperative lung function is warranted.
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Affiliation(s)
- Rodolfo C Morice
- Department of Pulmonary Medicine, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd. Unit 1462, Houston, Texas, 77030, USA
| | - Carlos A Jimenez
- Department of Pulmonary Medicine, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd. Unit 1462, Houston, Texas, 77030, USA
| | - Georgie A Eapen
- Department of Pulmonary Medicine, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd. Unit 1462, Houston, Texas, 77030, USA
| | - Reza J Mehran
- Department Thoracic and Cardiovascular Surgery, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd. Unit 0445, Houston, Texas, 77030, USA
| | - Leendert Keus
- Department of Pulmonary Medicine, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd. Unit 1462, Houston, Texas, 77030, USA
| | - David Ost
- Department of Pulmonary Medicine, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd. Unit 1462, Houston, Texas, 77030, USA
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Acoustic thoracic image of crackle sounds using linear and nonlinear processing techniques. Med Biol Eng Comput 2010; 49:15-24. [DOI: 10.1007/s11517-010-0663-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2010] [Accepted: 07/04/2010] [Indexed: 10/19/2022]
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Bartziokas K, Daenas C, Preau S, Zygoulis P, Triantaris A, Kerenidi T, Makris D, Gourgoulianis KI, Daniil Z. Vibration response imaging: evaluation of rater agreement in healthy subjects and subjects with pneumonia. BMC Med Imaging 2010; 10:6. [PMID: 20222975 PMCID: PMC2848624 DOI: 10.1186/1471-2342-10-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2009] [Accepted: 03/11/2010] [Indexed: 11/21/2022] Open
Abstract
Background We evaluated pulmonologists variability in the interpretation of Vibration response imaging (VRI) obtained from healthy subjects and patients hospitalized for community acquired pneumonia. Methods The present is a prospective study conducted in a tertiary university hospital. Twenty healthy subjects and twenty three pneumonia cases were included in this study. Six pulmonologists blindly analyzed images of normal subjects and pneumonia cases and evaluated different aspects of VRI images related to the quality of data aquisition, synchronization of the progression of breath sound distribution and agreement between the maximal energy frame (MEF) of VRI (which is the maximal geographical area of lung vibrations produced at maximal inspiration) and chest radiography. For qualitative assessment of VRI images, the raters' evaluations were analyzed by degree of consistency and agreement. Results The average value for overall identical evaluations of twelve features of the VRI image evaluation, ranged from 87% to 95% per rater (94% to 97% in control cases and from 79% to 93% per rater in pneumonia cases). Inter-rater median (IQR) agreement was 91% (82-96). The level of agreement according to VRI feature evaluated was in most cases over 80%; intra-class correlation (ICC) obtained by using a model of subject/rater for the averaged features was overall 0.86 (0.92 in normal and 0.73 in pneumonia cases). Conclusions Our findings suggest good agreement in the interpretation of VRI data between different raters. In this respect, VRI might be helpful as a radiation free diagnostic tool for the management of pneumonia.
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Accuracy of gray-scale coding in lung sound mapping. Comput Med Imaging Graph 2010; 34:362-9. [PMID: 20171843 DOI: 10.1016/j.compmedimag.2009.12.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2009] [Revised: 10/06/2009] [Accepted: 12/14/2009] [Indexed: 11/28/2022]
Abstract
Stethoscope evaluation of the lungs is widely accepted and practiced; however, there are some widely recognized, major limitations with its use. A safe device that helped solve these limitations by translating sound into objective, quantifiable images would have clinical utility. Translating lung sounds into quantifiable images in which regional differences or asymmetry in intensities of breath sounds are presented as gradients in gray-scale is not a trivial process. Healthy lungs and lung pathology are characterized by different patterns of regional breath sound distribution and, therefore, the accuracy of mapping gray-scale images must be ensured in a controlled systematic fashion prior to clinical use of such a technique. Vibration response imaging (VRI) maps lung sounds from 40 sensors to a two-dimensional gray-scale image. To assess mapping accuracy, a simulated lung sound map with uniform signals was compared to modified maps where sound signals were reduced (1-3db) at one sensor. Also, 8 readers evaluated the gray-scale images. The computer algorithm accurately displayed gray-scale coding changes in correct locations in 97% of images. There was 95+/-4% accuracy rate by readers to correctly identify gray-scale changes. In addition, quantitative data at different stages of signal processing were investigated in a LSM of a subject with asthma. Signal processing was 97% accurate overall in that the gray-scale values from which the image was derived corresponded with intensity values from recorded signals. These results suggest VRI accurately maps acoustic signals to a gray-scale image and that trained readers can detect small changes.
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Wang Z, Baumann BM, Slutsky K, Gruber KN, Jean S. Respiratory sound energy and its distribution patterns following clinical improvement of congestive heart failure: a pilot study. BMC Emerg Med 2010; 10:1. [PMID: 20078862 PMCID: PMC2821310 DOI: 10.1186/1471-227x-10-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2009] [Accepted: 01/15/2010] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Although congestive heart failure (CHF) patients typically present with abnormal auscultatory findings on lung examination, respiratory sounds are not normally subjected to additional analysis. The aim of this pilot study was to examine respiratory sound patterns of CHF patients using acoustic-based imaging technology. Lung vibration energy was examined during acute exacerbation and after clinical improvement. METHODS Respiratory sounds throughout the respiratory cycle were captured using an acoustic-based imaging technique. Twenty-three consecutive CHF patients were imaged at the time of presentation to the emergency department and after clinical improvement. Digital images were created (a larger image represents more homogeneously distributed vibration energy of respiratory sound). Geographical area of the images and respiratory sound patterns were quantitatively analyzed. Data from the CHF patients were also compared to healthy volunteers. RESULTS The median (interquartile range) geographical areas of the vibration energy image of acute CHF patients without and with radiographically evident pulmonary edema were 66.9 (9.0) and 64.1(9.0) kilo-pixels, respectively (p < 0.05). After clinical improvement, the geographical area of the vibration energy image of CHF patients without and with radiographically evident pulmonary edema were increased by 18 +/- 15% (p < 0.05) and 25 +/- 16% (p < 0.05), respectively. CONCLUSIONS With clinical improvement of acute CHF exacerbations, there was more homogenous distribution of lung vibration energy, as demonstrated by the increased geographical area of the vibration energy image.
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Affiliation(s)
- Zhen Wang
- Division of Critical Care Medicine, Robert Wood Johnson School of Medicine - University of Medicine and Dentistry of New Jersey - Cooper University Hospital, One Cooper Plaza, Camden, NJ 08103, USA
- Department of Emergency Medicine, Beijing Shi-ji-tan Hospital, 10 Tie Yi Rd., Haidian District Beijing 100038, PR China
| | - Brigitte M Baumann
- Department of Emergency Medicine, Robert Wood Johnson School of Medicine - University of Medicine and Dentistry of New Jersey - Cooper University Hospital, One Cooper Plaza, Camden, NJ 08103, USA
| | - Karen Slutsky
- Department of Emergency Medicine, Robert Wood Johnson School of Medicine - University of Medicine and Dentistry of New Jersey - Cooper University Hospital, One Cooper Plaza, Camden, NJ 08103, USA
| | - Karen N Gruber
- Department of Emergency Medicine, Robert Wood Johnson School of Medicine - University of Medicine and Dentistry of New Jersey - Cooper University Hospital, One Cooper Plaza, Camden, NJ 08103, USA
| | - Smith Jean
- Division of Critical Care Medicine, Robert Wood Johnson School of Medicine - University of Medicine and Dentistry of New Jersey - Cooper University Hospital, One Cooper Plaza, Camden, NJ 08103, USA
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Bodmann I, Dierich M, Fuehner T, Simon A, Welte T, Gottlieb J. Vibration response imaging (VRI) in lung transplant recipients. Ther Adv Respir Dis 2010; 4:3-11. [PMID: 20042451 DOI: 10.1177/1753465809356293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND In the first 6 months following lung transplantation, the most frequently occurring complications are infection, acute rejection and anastomotic dysfunction. The utility of vibration response imaging (VRI) lung images in assisting with the detection of these complications was evaluated. OBJECTIVES The study aimed to evaluate if VRI is a good, non-invasive method of detecting clinical problems in lung transplant (LTx) recipients during early follow-up. METHODS Between 06/2006 and 03/2007 all LTx patients who received transplants during the preceding 6 months at the Hannover Medical School received baseline VRI at enrollment with subsequent reassessment in combination with standard follow-up at 1, 3 and 6 months thereafter. The resulting images were analysed by two blinded reviewers. RESULTS Fifty-five lung transplant recipients were enrolled in the study, with 49 patients successfully completing follow-up. Device operability and patient participation occurred without significant problems. High numbers of abnormal scans were detected. According to the clinical diagnosis, 29 patients (59.2 %) were stable at all four visits. Twenty clinical problems occurred (e.g., infections, rejections, obstructions, unknown deterioration). Agreement with clinical interpretation of rejections and infections was poor. Central airway obstruction (CAO) was detected in 80% by both reviewers. Accuracy in detecting obstructions was 89%; positive predicted value and negative predicted value were 80% and 90%, respectively. CONCLUSION The VRI system is a non-invasive easy-to-use method with technical success and good image quality. The high number of abnormal scans makes interpretation following LTx difficult. VRI was unable to detect deterioration in graft function with the exception of ventilation disorders like central airway complications.
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Affiliation(s)
- Isabelle Bodmann
- Hannover Medical School, Department of Respiratory Medicine, Hannover, Germany.
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Yosef M, Langer R, Lev S, Glickman YA. Effect of airflow rate on vibration response imaging in normal lungs. Open Respir Med J 2009; 3:116-22. [PMID: 19834576 PMCID: PMC2761668 DOI: 10.2174/1874306400903010116] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2009] [Revised: 08/10/2009] [Accepted: 08/21/2009] [Indexed: 12/02/2022] Open
Abstract
Background: Evaluating the effect of airflow rate on amplitude of lung sound energy and regional distribution of lung sounds may assist in the interpretation of computerized acoustic measurements. Objectives: The aim of this study was to assess the effect of airflow rate on Vibration Response Imaging (VRI) measurement in healthy lungs. Methods: Lung sounds were recorded from 20 healthy adults in the frequency range of 150-250 Hz using 40 piezoelectric sensors positioned on the posterior chest wall. During the recordings, subjects were breathing at airflow rates ranging between 0.3 and 1.7L/s. Online visual feedback was provided using a pneumotach mouthpiece. Results: Amplitude of lung sound energy significantly increased with increasing airflow rate (p<0.00001, Friedman test). A strong relationship (R2=0.95) was obtained between amplitude of lung sound energy at peak inspiration and airflow rate raised to the third power. This correlation did not significantly affect normalized lung sound distribution maps at peak inspiration, especially when airflow was higher than 1.0L/s. Acoustic maps obtained at airflow rates below 0.7L/s differed from those recorded above 1.0L/s (p<0.05, Wilcoxon matched-paired signed-ranks test). Conclusion: These findings may be of importance when comparing healthy and diseased lungs or when monitoring changes in lung sounds during treatment follow-up.
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Affiliation(s)
- Meirav Yosef
- Deep Breeze, Ltd., 2 Hailan St., P.O. Box 140, Or-Akiva, 30600, Israel
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Lev S, Glickman YA, Kagan I, Dahan D, Cohen J, Grinev M, Shapiro M, Singer P. Changes in regional distribution of lung sounds as a function of positive end-expiratory pressure. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2009; 13:R66. [PMID: 19426555 PMCID: PMC2717423 DOI: 10.1186/cc7871] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/07/2008] [Revised: 04/27/2009] [Accepted: 05/10/2009] [Indexed: 11/17/2022]
Abstract
Introduction Automated mapping of lung sound distribution is a novel area of interest currently investigated in mechanically ventilated, critically ill patients. The objective of the present study was to assess changes in thoracic sound distribution resulting from changes in positive end-expiratory pressure (PEEP). Repeatability of automated lung sound measurements was also evaluated. Methods Regional lung sound distribution was assessed in 35 mechanically ventilated patients in the intensive care unit (ICU). A total of 201 vibration response imaging (VRI) measurements were collected at different levels of PEEP between 0 and 15 cmH2O. Findings were correlated with tidal volume, oxygen saturation, airway resistance, and dynamic compliance. Eighty-two duplicated readings were performed to evaluate the repeatability of the measurement. Results A significant shift in sound distribution from the apical to the diaphragmatic lung areas was recorded when increasing PEEP (paired t-tests, P < 0.05). In patients with unilateral lung pathology, this shift was significant in the diseased lung, but not as pronounced in the other lung. No significant difference in lung sound distribution was encountered based on level of ventilator support needed. Decreased lung sound distribution in the base was correlated with lower dynamic compliance. No significant difference was encountered between repeated measurements. Conclusions Lung sounds shift towards the diaphragmatic lung areas when PEEP increases. Lung sound measurements are highly repeatable in mechanically ventilated patients with various lung pathologies. Further studies are needed in order to fully appreciate the contribution of PEEP increase to diaphragmatic sound redistribution.
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Affiliation(s)
- Shaul Lev
- Department of General Intensive Care, Rabin Medical Center, Beilinson Campus, Petach Tikva 49100, Israel.
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Guntupalli KK, Reddy RM, Loutfi RH, Alapat PM, Bandi VD, Hanania NA. Evaluation of obstructive lung disease with vibration response imaging. J Asthma 2009; 45:923-30. [PMID: 19085584 DOI: 10.1080/02770900802395496] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
As optimal treatment and prognosis differ between asthma and COPD, a new diagnostic approach to differentiating between the two disorders would be clinically desirable. We evaluated the utility of vibration response imaging in differentiating between asthma and COPD. Sixty-six subjects with asthma or COPD were recorded, before and after the administration of a short-acting bronchodilator, using a computerized lung sound analysis device. Gray-scale images of breath sound distribution in the lungs, quantitative data in breath sound graphs (timing, amplitude) and automatic crackle and wheeze detection programs were used to differentiate between asthma and COPD subjects. Imaging data were compared with the clinical diagnosis, made by the standard methods (medical history, physical examination, and spirometric indices). Blinded evaluation of images demonstrated a significantly higher rate of improvement in image dynamics, shape and overall improvement following bronchodilator in subjects with asthma compared with those with COPD. Quantitative data showed distinct patterns in timing and amplitude for these two pathologies. Combined analyses based on qualitative image evaluation and quantitative data demonstrated an overall 85% accuracy (84% for asthma, 86% for COPD) in differentiating between asthma and COPD. Combined qualitative and quantitative evaluations of lung sounds are quite sensitive in distinguishing between lung sound recordings of COPD and asthma individuals. Lung sound features of synchronization in timing and intensity provide objective data that may further differentiate these two airway disorders.
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Affiliation(s)
- Kalpalatha K Guntupalli
- Baylor College of Medicine, Ben Taub General Hospital, 1504 Taub Loop, Houston, Texas 77030, USA.
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Guntupalli KK, Alapat PM, Bandi VD, Kushnir I. Validation of automatic wheeze detection in patients with obstructed airways and in healthy subjects. J Asthma 2009; 45:903-7. [PMID: 19085580 DOI: 10.1080/02770900802386008] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Computerized lung-sound analysis is a sensitive and quantitative method to identify wheezing by its typical pattern on spectral analysis. We evaluated the accuracy of the VRI, a multi-sensor, computer-based device with an automated technique of wheeze detection. The method was validated in 100 sound files from seven subjects with asthma or chronic obstructive pulmonary disease and seven healthy subjects by comparison of auscultation findings, examination of audio files, and computer detection of wheezes. Three blinded physicians identified 40 sound files with wheezes and 60 sound files without wheezes. Sensitivity and specificity were 83% and 85%, respectively. Negative predictive value and positive predictive value were 89% and 79%, respectively. Overall inter-rater agreement was 84%. False positive cases were found to contain sounds that simulate wheezes, such as background noises with high frequencies or strong noises from the throat that could be heard and identified without a stethoscope. The present findings demonstrate that the wheeze detection algorithm has good accuracy, sensitivity, specificity, negative predictive value and positive predictive value for wheeze detection in regional analyses with a single sensor and multiple sensors. Results are similar to those reported in the literature. The device is user-friendly, requires minimal patient effort, and, distinct from other devices, it provides a dynamic image of breath sound distribution with wheeze detection output in less than 1 minute.
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Affiliation(s)
- Kalpalatha K Guntupalli
- Baylor College of Medicine, Ben Taub General Hospital, 1504 Taub Loop, Houston, Texas 77030, USA.
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Jean S, Cinel I, Tay C, Parrillo JE, Dellinger RP. Assessment of asymmetric lung disease in intensive care unit patients using vibration response imaging. Anesth Analg 2008; 107:1243-7. [PMID: 18806034 DOI: 10.1213/ane.0b013e3181804a99] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND Vibration response imaging (VRI) is a computer-based technology that creates a visual dynamic two-dimensional image of distribution of vibration within the lung during the respiratory process. The acoustic signals, recorded from 36 posteriorly positioned surface skin sensors, are transferred to a hardware board where several stages of filtering are applied to select a specific frequency band. The filtered output signal frequencies are presented as a gray-scale coded dynamic image, consisting of a series of 0.17 s frames, and as a table featuring the percentage contribution of each lung to the total vibration signal. METHODS We describe the VRI technology in detail and examine images obtained from consecutive intensive care unit (ICU) patients with one diseased lung on chest radiograph. ICU patients with normal chest radiographs are presented as controls. Analysis of the image was performed by comparing the weighted pixel count analysis from both lungs. In this method, the pixels in the image were assigned values based on their grayscale color with the darker pixels assigned higher values. RESULTS In patients with normal chest radiographs, the right and left lungs developed similarly in dynamic VRI images, and the percent lung vibrations from both sides were comparable (53%+/-12% and 47%+/-12%, respectively). In ICU patients with asymmetric lung disease, however, the percent lung vibrations from the diseased and nondiseased lungs were 27%+/-23% and 73%+/-23%, respectively (P<0.001). In patients with asymmetric lung disease (one lung has moderate to severe disease and the other appears normal or close to normal as per chest radiograph), the diseased lung usually appeared in VRI as irregular, smaller, and lighter in color (reduced vibration signal) when compared to the nonaffected lung. The weighted pixel count from diseased and nondiseased lungs were 33%+/-21% and 67%+/-21%, respectively (P < 0.003). CONCLUSION The VRI technology may provide a radiation-free method for identifying and tracking of asymmetric lung parenchymal processes.
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Affiliation(s)
- Smith Jean
- Department of Medicine, Robert Wood Johnson School of Medicine, University of Medicine and Dentistry of New Jersey, Cooper University Hospital, Camden, NJ 08103, USA
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