Heterogeneous Distribution of Pulmonary Ventilation in Intensive Care Patients Detected by Functional Electrical Impedance Tomography

1998 ◽  
Vol 13 (4) ◽  
pp. 168-173 ◽  
Author(s):  
Inéz Frerichs ◽  
Wolfgang Golisch ◽  
Günter Hahn ◽  
Kurpitz Michael ◽  
Hilmar Burchardi ◽  
...  
Keyword(s):  
Intensive Care ◽  
Electrical Impedance Tomography ◽  
Electrical Impedance ◽  
Pulmonary Ventilation ◽  
Bronchial Carcinoma ◽  
Biological Tissues ◽  
The Body ◽  
Impedance Tomography ◽  
Heterogeneous Distribution ◽  
Intensive Care Patients

Electrical impedance tomography (EIT) is a new noninvasive imaging technique which utilizes the different electrical properties of biological tissues to produce cross-sectional images of selected parts of the body. When applied on the thorax, the cyclic fluctuations of electrical impedance of the lung tissue, associated with different air contents of the lungs in the course of the respiratory cycle, can be used to generate derived EIT tomograms which represent the spatial distribution of ventilation in the chosen transverse plane. The corresponding evaluation technique, the functional EIT, was used for the first time to follow the regional ventilation in three intensive care patients. The method was shown (1) to identify the redistribution of inspired air in the lungs associated with controlled ventilation in a patient undergoing elective laparotomy, (2) to follow the improvement of locally impaired lung ventilation in the course of severe pneumonia, and (3) to detect regional reduction of ventilation due to lobar atelectasis with stasis pneumonia in a patient with bronchial carcinoma.

scholarly journals Evaluation of Regional Pulmonary Ventilation in Spontaneously Breathing Patients with Idiopathic Pulmonary Fibrosis (IPF) Employing Electrical Impedance Tomography (EIT): A Pilot Study from the European IPF Registry (eurIPFreg)

2021 ◽  
Vol 10 (2) ◽  
pp. 192
Author(s):  
Ekaterina Krauss ◽  
Daniel van der Beck ◽  
Isabel Schmalz ◽  
Jochen Wilhelm ◽  
Silke Tello ◽  
...  
Keyword(s):  
Idiopathic Pulmonary Fibrosis ◽  
Pulmonary Fibrosis ◽  
Electrical Impedance Tomography ◽  
Spontaneous Breathing ◽  
Electrical Impedance ◽  
Statistical Significance ◽  
Pulmonary Ventilation ◽  
Healthy Controls ◽  
Impedance Tomography ◽  
Spontaneously Breathing

Objectives: In idiopathic pulmonary fibrosis (IPF), alterations in the pulmonary surfactant system result in an increased alveolar surface tension and favor repetitive alveolar collapse. This study aimed to assess the usefulness of electrical impedance tomography (EIT) in characterization of regional ventilation in IPF. Materials and methods: We investigated 17 patients with IPF and 15 healthy controls from the University of Giessen and Marburg Lung Center (UGMLC), Germany, for differences in the following EIT parameters: distribution of ventilation (TID), global inhomogeneity index (GI), regional impedance differences through the delta of end-expiratory lung impedance (dEELI), differences in surface of ventilated area (SURF), as well as center of ventilation (CG) and intratidal gas distribution (ITV). These parameters were assessed under spontaneous breathing and following a predefined escalation protocol of the positive end-expiratory pressure (PEEP), applied through a face mask by an intensive care respirator (EVITA, Draeger, Germany). Results: Individual slopes of dEELI over the PEEP increment protocol were found to be highly significantly increased in both groups (p < 0.001) but were not found to be significantly different between groups. Similarly, dTID slopes were increasing in response to PEEP, but this did not reach statistical significance within or between groups. Individual breathing patterns were very heterogeneous. There were no relevant differences of SURF, GI or CGVD over the PEEP escalation range. A correlation of dEELI to FVC, BMI, age, or weight did not forward significant results. Conclusions: In this study, we did see a significant increase in dEELI and a non-significant increase in dTID in IPF patients as well as in healthy controls in response to an increase of PEEP under spontaneous breathing. We propose the combined measurements of EIT and lung function to assess regional lung ventilation in spontaneously breathing subjects.

Electrical Impedance Tomography of Cell Viability in Tissue With Application to Cryosurgery

2004 ◽  
Vol 126 (2) ◽  
pp. 305-309 ◽  
Author(s):  
Rafael Davalos ◽  
Boris Rubinsky
Keyword(s):  
Electrical Properties ◽  
Electrical Impedance Tomography ◽  
Electrical Impedance ◽  
Cell Damage ◽  
Membrane Integrity ◽  
The Body ◽  
Impedance Tomography ◽  
Cell Membrane Integrity ◽  
Minimally Invasive Surgical Procedure ◽  
Minimally Invasive Surgical

Tissue damage that is associated with the loss of cell membrane integrity should alter the bulk electrical properties of the tissue. This study shows that electrical impedance tomography (EIT) should be able to detect and image necrotic tissue inside the body due to the permeabilization of the membrane to ions. Cryosurgery, a minimally invasive surgical procedure that uses freezing to destroy undesirable tissue, was used to investigate the hypothesis. Experimental results with liver tissue demonstrate that cell damage during freezing results in substantial changes in tissue electrical properties. Two-dimensional EIT simulations of liver cryosurgery, which employ the experimental data, demonstrate the feasibility of this application.

scholarly journals Redistribution of pulmonary ventilation after lung surgery detected with electrical impedance tomography

2019 ◽  
Vol 64 (4) ◽  
pp. 517-525 ◽  
Author(s):  
Martin Lehmann ◽  
Beatrice Oehler ◽  
Jonas Zuber ◽  
Uwe Malzahn ◽  
Thorsten Walles ◽  
...  
Keyword(s):  
Electrical Impedance Tomography ◽  
Electrical Impedance ◽  
Pulmonary Ventilation ◽  
Lung Surgery ◽  
Impedance Tomography

Combined effects of body positioning and noninvasive ventilation on the regional distribution of pulmonary ventilation evaluated by electrical impedance tomography in the young and the elderly

2019 ◽  
Author(s):  
Liegina Silveira Marinho ◽  
Andrea Nobrega Cirino Nogueira Da Nobrega Cirino Nogueira ◽  
Juliana Arcanjo Lino ◽  
Gabriela De Carvalho Gomes Frota ◽  
Renata Dos Santos Vasconcelos ◽  
...  
Keyword(s):  
Electrical Impedance Tomography ◽  
Noninvasive Ventilation ◽  
Electrical Impedance ◽  
Pulmonary Ventilation ◽  
Regional Distribution ◽  
The Elderly ◽  
Combined Effects ◽  
Impedance Tomography ◽  
Body Positioning

Patient examinations using electrical impedance tomography—sources of interference in the intensive care unit

2011 ◽  
Vol 32 (12) ◽  
pp. L1-L10 ◽  
Author(s):  
Inéz Frerichs ◽  
Sven Pulletz ◽  
Gunnar Elke ◽  
Barbara Gawelczyk ◽  
Alexander Frerichs ◽  
...  
Keyword(s):  
Intensive Care Unit ◽  
Intensive Care ◽  
Electrical Impedance Tomography ◽  
Electrical Impedance ◽  
Impedance Tomography

Determination of optimal positive end-expiratory pressure based on respiratory compliance and electrical impedance tomography: a pilot clinical comparative trial

2019 ◽  
Vol 64 (2) ◽  
pp. 135-145 ◽  
Author(s):  
Jan Karsten ◽  
Nicolas Voigt ◽  
Hans-Joerg Gillmann ◽  
Thomas Stueber
Keyword(s):  
Electrical Impedance Tomography ◽  
Electrical Impedance ◽  
Peep Level ◽  
Pilot Trial ◽  
Comparative Trial ◽  
Positive End Expiratory Pressure ◽  
Impedance Tomography ◽  
Gold Standard Method ◽  
Intensive Care Patients ◽  
Respiratory Compliance

Abstract There is no agreement on gold standard method for positive end-expiratory pressure (PEEP) titration. Electrical impedance tomography (EIT) may aid in finding the optimal PEEP level. In this pilot trial, we investigated potential differences in the suggested optimal PEEP (BestPEEP) as derived by respiratory compliance and EIT-derived parameters. We examined if compliance-derived PEEP differs with regard to the regional ventilation distribution in relation to atelectasis and hyperinflation. Measurements were performed during an incremental/decremental PEEP trial in 15 ventilated intensive care patients suffering from mild-to-moderate impairment of oxygenation due to sepsis, pneumonia, trauma and metabolic and ischemic disorders. Measurement agreement was analyzed using Bland-Altman plots. We observed a diversity of EIT-derived and compliance-based optimal PEEP in the evaluated patients. BestPEEPCompliance did not necessarily correspond to the BestPEEPODCL with the least regional overdistension and collapse. The collapsed area was significantly smaller when the overdistension/collapse index was used for PEEP definition (p=0.022). Our results showed a clinically relevant difference in the suggested optimal PEEP levels when using different parameters for PEEP titration. The compliance-derived PEEP level revealed a higher proportion of residual regional atelectasis as compared to EIT-based PEEP.

scholarly journals Evaluation of reconstruction parameters of electrical impedance tomography on aorta detection during saline bolus injection

2016 ◽  
Vol 2 (1) ◽  
pp. 511-514 ◽  
Author(s):  
Florian Thürk ◽  
Andreas D. Waldmann ◽  
Karin H. Wodack ◽  
Constantin J. Trepte ◽  
Daniel Reuter ◽  
...  
Keyword(s):  
Electrical Impedance Tomography ◽  
Electrical Impedance ◽  
Bolus Injection ◽  
Noise Figure ◽  
Early Stage ◽  
The Body ◽  
Detection Accuracy ◽  
Impedance Tomography ◽  
Saline Bolus ◽  
Hemodynamic Processes

AbstractAn accurate detection of anatomical structures in electrical impedance tomography (EIT) is still at an early stage. Aorta detection in EIT is of special interest, since it would favor non-invasive assessment of hemodynamic processes in the body. Here, diverse EIT reconstruction parameters of the GREIT algorithm were systematically evaluated to detect the aorta after saline bolus injection in apnea. True aorta position and size were taken from computed tomography (CT). A comparison with CT showed that the smallest error for aorta displacement was attained for noise figure nf = 0.7, weighting radius rw = 0.15, and target size ts = 0.01. The spatial extension of the aorta was most precise for nf = 0.7, rw = 0.25, and ts = 0.07. Detection accuracy (F1-score) was highest with nf = 0.6, rw = 0.15, and ts = 0.04. This work provides algorithm-related evidence for potentially accurate aorta detection in EIT after injection of a saline bolus.

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