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Frerichs I, Vogt B, Deuss K, Hennig V, Schädler D, Händel C. Distribution of regional lung function in upright healthy subjects determined by electrical impedance tomography in two chest examination planes. Physiol Meas 2024; 45:015001. [PMID: 38096575 DOI: 10.1088/1361-6579/ad15ac] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Accepted: 12/14/2023] [Indexed: 12/20/2023]
Abstract
Objective. The variation in pulmonary gas content induced by ventilation is not uniformly distributed in the lungs. The aim of our study was to characterize the differences in spatial distribution of ventilation in two transverse sections of the chest using electrical impedance tomography (EIT).Approach. Twenty adult never-smokers, 10 women and 10 men (mean age ± SD, 31 ± 9 years), were examined in a sitting position with the EIT electrodes placed consecutively in a caudal (6th intercostal space) and a cranial (4th intercostal space) chest location. EIT data were acquired during quiet breathing, slow and forced full expiration manoeuvres. Impedance variations representing tidal volume (VT), vital capacity (VC), forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) were calculated at the level of individual image pixels and their spatial distribution was determined using the following EIT measures: the centres of ventilation in ventrodorsal (CoVvd) and right-to-left direction (CoVrl), the dorsal and right fractions of ventilation, the coefficient of variation (CV) and the global inhomogeneity (GI) index.Main results. The sums of pixel ventilation-related impedance variations reproduced reliably the volumetric dissimilarities amongVT, VC, FEV1and FVC, with no significant differences noted between the two examination planes. Significant differences in ventilation distribution were found between the planes during tidal breathing and slow full expiration, mainly regarding the ventrodorsal direction, with higher values of CoVvdand dorsal fraction of ventilation in the caudal plane (p< 0.01). No significant differences in the spatial distribution of FEV1and FVC were detected between the examination planes.Significance. The spatial distribution of ventilation differed between the two examination planes only during the relaxed (quiet breathing and slow VC manoeuvre) but not during the forced ventilation. This effect is attributable to the differences in thoracoabdominal mechanics between these types of ventilation.
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Affiliation(s)
- I Frerichs
- University Medical Centre Schleswig-Holstein, Campus Kiel, Department of Anaesthesiology and Intensive Care Medicine, Kiel, Germany
| | - B Vogt
- University Medical Centre Schleswig-Holstein, Campus Kiel, Department of Anaesthesiology and Intensive Care Medicine, Kiel, Germany
| | - K Deuss
- University Medical Centre Schleswig-Holstein, Campus Kiel, Department of Anaesthesiology and Intensive Care Medicine, Kiel, Germany
| | - V Hennig
- University Medical Centre Schleswig-Holstein, Campus Kiel, Department of Anaesthesiology and Intensive Care Medicine, Kiel, Germany
| | - D Schädler
- University Medical Centre Schleswig-Holstein, Campus Kiel, Department of Anaesthesiology and Intensive Care Medicine, Kiel, Germany
| | - C Händel
- University Medical Centre Schleswig-Holstein, Campus Kiel, Department of Anaesthesiology and Intensive Care Medicine, Kiel, Germany
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2
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Haris K, Vogt B, Strodthoff C, Pessoa D, Cheimariotis GA, Rocha B, Petmezas G, Weiler N, Paiva RP, de Carvalho P, Maglaveras N, Frerichs I. Identification and analysis of stable breathing periods in electrical impedance tomography recordings. Physiol Meas 2021; 42. [PMID: 34098533 DOI: 10.1088/1361-6579/ac08e5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 06/07/2021] [Indexed: 11/11/2022]
Abstract
Objective. In this paper, an automated stable tidal breathing period (STBP) identification method based on processing electrical impedance tomography (EIT) waveforms is proposed and the possibility of detecting and identifying such periods using EIT waveforms is analyzed. In wearable chest EIT, patients breathe spontaneously, and therefore, their breathing pattern might not be stable. Since most of the EIT feature extraction methods are applied to STBPs, this renders their automatic identification of central importance.Approach. The EIT frame sequence is reconstructed from the raw EIT recordings and the raw global impedance waveform (GIW) is computed. Next, the respiratory component of the raw GIW is extracted and processed for the automatic respiratory cycle (breath) extraction and their subsequent grouping into STBPs.Main results. We suggest three criteria for the identification of STBPs, namely, the coefficient of variation of (i) breath tidal volume, (ii) breath duration and (iii) end-expiratory impedance. The total number of true STBPs identified by the proposed method was 294 out of 318 identified by the expert corresponding to accuracy over 90%. Specific activities such as speaking, eating and arm elevation are identified as sources of false positives and their discrimination is discussed.Significance. Simple and computationally efficient STBP detection and identification is a highly desirable component in the EIT processing pipeline. Our study implies that it is feasible, however, the determination of its limits is necessary in order to consider the implementation of more advanced and computationally demanding approaches such as deep learning and fusion with data from other wearable sensors such as accelerometers and microphones.
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Affiliation(s)
- K Haris
- Lab of Computing, Medical Informatics and Biomedical Imaging Technologies, Aristotle University, Thessaloniki, Greece.,Department of Informatics and Computer Engineering, University of West Attica, Greece
| | - B Vogt
- Department of Anaesthesiology and Intensive Care Medicine, University Medical Centre Schleswig-Holstein, Campus Kiel, Germany
| | - C Strodthoff
- Department of Anaesthesiology and Intensive Care Medicine, University Medical Centre Schleswig-Holstein, Campus Kiel, Germany
| | - D Pessoa
- University of Coimbra, Centre for Informatics and Systems of the University of Coimbra, Department of Informatics Engineering, 3030-290 Coimbra, Portugal
| | - G-A Cheimariotis
- Lab of Computing, Medical Informatics and Biomedical Imaging Technologies, Aristotle University, Thessaloniki, Greece
| | - B Rocha
- University of Coimbra, Centre for Informatics and Systems of the University of Coimbra, Department of Informatics Engineering, 3030-290 Coimbra, Portugal
| | - G Petmezas
- Lab of Computing, Medical Informatics and Biomedical Imaging Technologies, Aristotle University, Thessaloniki, Greece
| | - N Weiler
- Department of Anaesthesiology and Intensive Care Medicine, University Medical Centre Schleswig-Holstein, Campus Kiel, Germany
| | - R P Paiva
- University of Coimbra, Centre for Informatics and Systems of the University of Coimbra, Department of Informatics Engineering, 3030-290 Coimbra, Portugal
| | - P de Carvalho
- University of Coimbra, Centre for Informatics and Systems of the University of Coimbra, Department of Informatics Engineering, 3030-290 Coimbra, Portugal
| | - N Maglaveras
- Lab of Computing, Medical Informatics and Biomedical Imaging Technologies, Aristotle University, Thessaloniki, Greece.,Department of Electrical and Computer Engineering, Northwestern University, Evanston, IL, United States of America
| | - I Frerichs
- Department of Anaesthesiology and Intensive Care Medicine, University Medical Centre Schleswig-Holstein, Campus Kiel, Germany
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3
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Lasarow L, Vogt B, Zhao Z, Balke L, Weiler N, Frerichs I. Regional lung function measures determined by electrical impedance tomography during repetitive ventilation manoeuvres in patients with COPD. Physiol Meas 2021; 42:015008. [PMID: 33434902 DOI: 10.1088/1361-6579/abdad6] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
OBJECTIVE Current standards for conducting spirometry examinations recommend that the ventilation manoeuvres needed in pulmonary function testing are carried out repeatedly during sessions. Chest electrical impedance tomography (EIT) can determine the presence of ventilation heterogeneity during such manoeuvres, which increases the information content derived from such examinations. The aim of this study was to characterise regional lung function in patients with chronic obstructive pulmonary disease (COPD) during repetitive forced full ventilation manoeuvres. Regional lung function measures derived from these manoeuvres were compared with quiet tidal breathing. APPROACH Sixty hospitalised patients were examined during up to three repeated ventilation manoeuvres. Acceptable spirometry manoeuvres were performed and EIT recordings suitable for analysis obtained in 53 patients (12 women, 41 men; age: 68 ± 12 years (mean ± SD)). Pixel values of tidal volume, forced full inspiratory and expiratory volume in 1 s, and forced inspiratory and expiratory vital capacity were calculated from the EIT data. Spatial ventilation heterogeneity was assessed using the coefficient of variation, global inhomogeneity index, and centres and regional fractions of ventilation. Temporal inhomogeneity was determined by examining the pixel expiration times needed to exhale 50% and 75% of regional forced vital capacity. MAIN RESULTS All EIT-derived measures of regional lung function showed reproducible results during repetitive examinations. Parameters of spatial heterogeneity obtained from quiet tidal breathing were comparable with the measures derived from the forced manoeuvres. SIGNIFICANCE Measures of spatial and temporal ventilation heterogeneity obtained in COPD patients by EIT provide comparable findings during repeated examinations within one testing session. Quiet tidal breathing generates similar information on ventilation heterogeneity as forced manoeuvres that demand a high amount of patient effort.
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Affiliation(s)
- L Lasarow
- Department of Anaesthesiology and Intensive Care Medicine, University Medical Centre Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - B Vogt
- Department of Anaesthesiology and Intensive Care Medicine, University Medical Centre Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Z Zhao
- Institute of Technical Medicine, Furtwangen University, Villingen-Schwenningen, Germany.,Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, People's Republic of China
| | - L Balke
- Department of Pneumology, University Medical Centre Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - N Weiler
- Department of Anaesthesiology and Intensive Care Medicine, University Medical Centre Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - I Frerichs
- Department of Anaesthesiology and Intensive Care Medicine, University Medical Centre Schleswig-Holstein, Campus Kiel, Kiel, Germany
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Lanfranconi F, Ferri A, Pollastri L, Bartesaghi M, Novarina M, De Vito G, Beretta E, Tremolizzo L. Impact of Hanging Motionless in Harness on Respiratory and Blood Pressure Reflex Modulation in Mountain Climbers. High Alt Med Biol 2019; 20:122-132. [PMID: 31009248 PMCID: PMC6602116 DOI: 10.1089/ham.2018.0089] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Harness hang syncope (HHS) is a risk that specifically affects safety of harness users in mountain climbing. Aims: To evaluate individual patterns of breathing resulting from deranged cardiovascular reflexes triggering a syncopal event when a mismatch between cerebral O2 demand and supply is present. Results: Forty healthy participants [aged 39.1 (8.2) years] were enrolled in a motionless suspension test while hanging in harness. Respiratory gas exchange values were analyzed to assess the pattern of breathing (EpInWel, respiratory elastic power) and cardiovascular parameters were monitored (BP, blood pressure). Four participants experienced HHS after 30.0 (7.6) minutes, with an early manifestation of loss of control of both a sustainable EpInWel and BP, starting after 10–12 minutes. Among the other participants, two different reactions were observed during suspension: (1) group G1 tolerated 32.7 (11.4) minutes of suspension by a favorable adaptation of the EpInWel and BP parameters and (2) group G2 showed significantly shorter time of suspension 24.0 (10.4) minutes with unfavorable increase in EpInWel and BP. Conclusions: Greater resistance to HHS occurs in people developing less marked fluctuations of both respiratory and cardiovascular reflex responses. Conversely, wider fluctuations both in control of EpInWel and BP were observed in the event of decreased suspension tolerance or in syncopal events.
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Affiliation(s)
- Francesca Lanfranconi
- 1 School of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy.,2 Foundation Monza and Brianza for the Mother and Her Child, Monza, Italy
| | - Alessandra Ferri
- 1 School of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy.,3 Institute for Health and Sport, Victoria University, Melbourne, Australia
| | | | | | | | - Giovanni De Vito
- 1 School of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy
| | - Egidio Beretta
- 1 School of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy
| | - Lucio Tremolizzo
- 1 School of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy
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Chatwin M, Toussaint M, Gonçalves MR, Sheers N, Mellies U, Gonzales-Bermejo J, Sancho J, Fauroux B, Andersen T, Hov B, Nygren-Bonnier M, Lacombe M, Pernet K, Kampelmacher M, Devaux C, Kinnett K, Sheehan D, Rao F, Villanova M, Berlowitz D, Morrow BM. Airway clearance techniques in neuromuscular disorders: A state of the art review. Respir Med 2018; 136:98-110. [PMID: 29501255 DOI: 10.1016/j.rmed.2018.01.012] [Citation(s) in RCA: 121] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Revised: 01/20/2018] [Accepted: 01/22/2018] [Indexed: 12/13/2022]
Abstract
This is a unique state of the art review written by a group of 21 international recognized experts in the field that gathered during a meeting organized by the European Neuromuscular Centre (ENMC) in Naarden, March 2017. It systematically reports the entire evidence base for airway clearance techniques (ACTs) in both adults and children with neuromuscular disorders (NMD). We not only report randomised controlled trials, which in other systematic reviews conclude that there is a lack of evidence base to give an opinion, but also include case series and retrospective reviews of practice. For this review, we have classified ACTs as either proximal (cough augmentation) or peripheral (secretion mobilization). The review presents descriptions; standard definitions; the supporting evidence for and limitations of proximal and peripheral ACTs that are used in patients with NMD; as well as providing recommendations for objective measurements of efficacy, specifically for proximal ACTs. This state of the art review also highlights how ACTs may be adapted or modified for specific contexts (e.g. in people with bulbar insufficiency; children and infants) and recommends when and how each technique should be applied.
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Affiliation(s)
- Michelle Chatwin
- Academic and Clinical Department of Sleep and Breathing and NIHR Respiratory Biomedical Research Unit, Royal Brompton & Harefield NHS Foundation Trust, Sydney Street, London, UK.
| | - Michel Toussaint
- Centre for Home Mechanical Ventilation and Specialized Centre for Neuromuscular Diseases, Inkendaal Rehabilitation Hospital, Vlezenbeek, Belgium
| | - Miguel R Gonçalves
- Noninvasive Ventilatory Support Unit, Pulmonology Department, Emergency and Intensive Care Medicine Department, São João University Hospital, Faculty of Medicine, University of Porto, Portugal
| | - Nicole Sheers
- Institute for Breathing and Sleep and Victorian Respiratory Support Service, Austin Health, Melbourne, Australia
| | - Uwe Mellies
- Departement of Pediatric Pulmonology and Sleep Medicine, Cystic Fibrosis Center Essen, University of Essen, Germany
| | - Jesus Gonzales-Bermejo
- Sorbonne Université, UPMC Univ Paris 06, INSERM, UMRS1158 Neurophysiologie Respiratoire Expérimentale et Clinique, AP-HP, Groupe Hospitalier Pitié-Salpêtrière Charles Foix, Service de Pneumologie et Réanimation Médicale (Département "R3S"), Paris, France
| | - Jesus Sancho
- Respiratory Care Unit, Respiratory Medicine Department, Hospital Clinico Universitario, Valencia, Institute of Health Research INCLIVA, Valencia, Spain
| | - Brigitte Fauroux
- Pediatric Noninvasive Ventilation and Sleep Unit, Necker University Hospital, Paris, Paris Descartes University, Paris Research Unit INSERM U 955, Team 13, Creteil, France
| | - Tiina Andersen
- Norwegian Centre of Excellence for Home Mechanical Ventilation, Thoracic Department and Department of Physiotherapy, Haukeland University Hospital, Bergen Norway, Department of Clinical Science, Medical Faculty, University of Bergen, Bergen, Norway
| | - Brit Hov
- Dept of Peadiatric Medicine, Oslo University Hospital, Oslo, Norway and Norwegian Centre of Excellence for Home Mechanical Ventilation, Haukeland University Hospital, Bergen, Norway
| | - Malin Nygren-Bonnier
- Department of Neurobiology, Care Sciences and Society, Division of Physiotherapy, Karolinska Institutet, Functional Area Occupational Therapy and Physiotherapy, Allied Health Professionals Function, Karolinska University Hospital, Stockholm, Sweden
| | - Matthieu Lacombe
- Adult Intensive Care Unit, Raymond Poincaré Hospital (AP-HP) Garches, France
| | - Kurt Pernet
- Centre for Home Mechanical Ventilation and Specialized Centre for Neuromuscular Diseases, Inkendaal Rehabilitation Hospital, Vlezenbeek, Belgium
| | - Mike Kampelmacher
- Home Ventilation Service, University Medical Centre Utrecht, Utrecht, The Netherlands
| | - Christian Devaux
- Direction des Actions Médicales, Paramédicales et Psychologiques, Association Française Contre Les Myopathies-Téléthon, 91000 EVRY, France
| | - Kathy Kinnett
- Parent Project Muscular Dystrophy, 401 Hackensack Ave 9th Floor, Hackensack, NJ 07601, United States
| | - Daniel Sheehan
- Assisted Breathing Center, Women and Children's Hospital of Buffalo Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, The State University of New York, United States
| | - Fabrizio Rao
- Respiratory Unit, Neuromuscular OmniCentre (NeMO), Neurorehabilitation, University of Milan, Niguarda Hospital, Milan, Italy
| | - Marcello Villanova
- Neuromuscular Rehabilitation Unit, Nigrisoli Hospital, Viale Ercolani 7/b - 40125, Bologna, Italy
| | - David Berlowitz
- Institute for Breathing and Sleep and Victorian Respiratory Support Service, Austin Health, Melbourne, Australia
| | - Brenda M Morrow
- Department of Paediatrics and Child Health, University of Cape Town, Klipfontein Rd, Rondebosch, Cape Town, South Africa
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Ericsson E, Tesselaar E, Sjöberg F. Effect of Electrode Belt and Body Positions on Regional Pulmonary Ventilation- and Perfusion-Related Impedance Changes Measured by Electric Impedance Tomography. PLoS One 2016; 11:e0155913. [PMID: 27253433 PMCID: PMC4890811 DOI: 10.1371/journal.pone.0155913] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Accepted: 05/08/2016] [Indexed: 11/18/2022] Open
Abstract
Ventilator-induced or ventilator-associated lung injury (VILI/VALI) is common and there is an increasing demand for a tool that can optimize ventilator settings. Electrical impedance tomography (EIT) can detect changes in impedance caused by pulmonary ventilation and perfusion, but the effect of changes in the position of the body and in the placing of the electrode belt on the impedance signal have not to our knowledge been thoroughly evaluated. We therefore studied ventilation-related and perfusion-related changes in impedance during spontaneous breathing in 10 healthy subjects in five different body positions and with the electrode belt placed at three different thoracic positions using a 32-electrode EIT system. We found differences between regions of interest that could be attributed to changes in the position of the body, and differences in impedance amplitudes when the position of the electrode belt was changed. Ventilation-related changes in impedance could therefore be related to changes in the position of both the body and the electrode belt. Perfusion-related changes in impedance were probably related to the interference of major vessels. While these findings give us some insight into the sources of variation in impedance signals as a result of changes in the positions of both the body and the electrode belt, further studies on the origin of the perfusion-related impedance signal are needed to improve EIT further as a tool for the monitoring of pulmonary ventilation and perfusion.
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Affiliation(s)
- Elin Ericsson
- Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
| | - Erik Tesselaar
- Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
- Department of Radiation Physics, Department of Medical and Health Sciences, Linköping University, Linköping, Sweden
- * E-mail:
| | - Folke Sjöberg
- Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
- Department of Hand and Plastic Surgery and the Burn Clinic, Linköping University, Linköping, Sweden
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Antunes BO, de Souza HCD, Gianinis HH, Passarelli-Amaro RDCV, Tambascio J, Gastaldi AC. Peak expiratory flow in healthy, young, non-active subjects in seated, supine, and prone postures. Physiother Theory Pract 2016; 32:489-493. [PMID: 27253194 DOI: 10.3109/09593985.2016.1139646] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVE To compare the PEFs in healthy, young, non-active subjects in seated, supine, and prone postures. METHODS A total of 30 healthy volunteers (15 male, mean age 22.7 years, non-smokers, sedentary) underwent a physical examination, spirometry to confirm normal pulmonary function, and PEF using the Mini-Wright Peak Flow Meter while wearing a nose clip. PEF measurements were repeated three times in each of three positions (seated, prone, and supine) in random order and differed by less than 20 L/min for a given position. Paired Student's t-tests were used to analyze the results, and the significance level was set at 5%. RESULTS The PEF values obtained when the study participants were in a seated position (481.0 ± 115.1 L/min) were higher than those obtained when participants were in prone (453.7 ± 112.1 L/min) or supine (453.2 ± 114.3 L/min) positions (p < 0.05). No significant difference in PEF values was observed between the prone and supine positions. CONCLUSION Body posture affects PEF in healthy, young, non-active subjects. PEFs are higher when subjects are in a seated position compared to prone or supine positions, but no difference in PEF is observed between the prone and supine positions.
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Affiliation(s)
- Bianca Orestes Antunes
- a Physiotherapy Course, School of Medicine of Ribeirão Preto , São Paulo University , São Paulo , Brazil
| | - Hugo C Dutra de Souza
- a Physiotherapy Course, School of Medicine of Ribeirão Preto , São Paulo University , São Paulo , Brazil
| | - Heloisa Higuti Gianinis
- a Physiotherapy Course, School of Medicine of Ribeirão Preto , São Paulo University , São Paulo , Brazil
| | | | - Joana Tambascio
- b University Hospital, Ribeirão Preto Medical School, University of São Paulo , São Paulo , Brazil
| | - Ada C Gastaldi
- a Physiotherapy Course, School of Medicine of Ribeirão Preto , São Paulo University , São Paulo , Brazil
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8
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Vogt B, Mendes L, Chouvarda I, Perantoni E, Kaimakamis E, Becher T, Weiler N, Tsara V, Paiva RP, Maglaveras N, Frerichs I. Influence of torso and arm positions on chest examinations by electrical impedance tomography. Physiol Meas 2016; 37:904-21. [PMID: 27200486 DOI: 10.1088/0967-3334/37/6/904] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Electrical impedance tomography (EIT) is increasingly used in patients suffering from respiratory disorders during pulmonary function testing (PFT). The EIT chest examinations often take place simultaneously to conventional PFT during which the patients involuntarily move in order to facilitate their breathing. Since the influence of torso and arm movements on EIT chest examinations is unknown, we studied this effect in 13 healthy subjects (37 ± 4 years, mean age ± SD) and 15 patients with obstructive lung diseases (72 ± 8 years) during stable tidal breathing. We carried out the examinations in an upright sitting position with both arms adducted, in a leaning forward position and in an upright sitting position with consecutive right and left arm elevations. We analysed the differences in EIT-derived regional end-expiratory impedance values, tidal impedance variations and their spatial distributions during all successive study phases. Both the torso and the arm movements had a highly significant influence on the end-expiratory impedance values in the healthy subjects (p = 0.0054 and p < 0.0001, respectively) and the patients (p < 0.0001 in both cases). The global tidal impedance variation was affected by the torso, but not the arm movements in both study groups (p = 0.0447 and p = 0.0418, respectively). The spatial heterogeneity of the tidal ventilation distribution was slightly influenced by the alteration of the torso position only in the patients (p = 0.0391). The arm movements did not impact the ventilation distribution in either study group. In summary, the forward torso movement and the arms' abduction exert significant effects on the EIT waveforms during tidal breathing. We recommend strict adherence to the upright sitting position during PFT when EIT is used.
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Affiliation(s)
- B Vogt
- Department of Anaesthesiology and Intensive Care Medicine, University Medical Centre Schleswig-Holstein, Campus Kiel, Kiel, Germany
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9
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Caruana LR, Paratz J, Chang AT, Fraser JF. Electrical impedance tomography in the clinical assessment of lung volumes following recruitment manoeuvres. PHYSICAL THERAPY REVIEWS 2013. [DOI: 10.1179/1743288x10y.0000000021] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
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