Document Detail


Impedance tomography: computational analysis based on finite element models of a cylinder and a human thorax.
MedLine Citation:
PMID:  7762883     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
A direct image reconstruction method of electrical impedance tomography (EIT) is evaluated using three-dimensional (3-D) finite element models of cylindrical and torso-shaped volume conductors. The cylindrical model is used to examine the effect of electrode configurations and the sensitivity to off-plane objects and to noise in the measured data. It is also used to validate the modeling procedures by comparison with experimental data acquired from a similar cylindrical tank filled with saline. Simulation results show only minor differences in performance between the various electrode configurations. In the second part, a realistic human thorax model constructed from CT images is used to evaluate monitoring of pulmonary edema by EIT. The conductivity, volume, and vertical position of an abnormal region in the lungs are varied to simulate the progress of edema. Dynamic EIT images are reconstructed from data computed for the inhomogeneous thorax (heart and lungs) as the reference set and a realistic amount of noise is added to reproduce the conditions in which the technique would be used in practice. Simulation results show that a 10 ml edema region with a conductivity equal to that of blood can be detected at a 40 dB signal-to-noise ratio (SNR). Detection of a smaller volume, in the order of 2 ml, should be possible by improving either the instrumentation to achieve 60 dB SNR or the performance of reconstruction algorithms.
Authors:
A V Shahidi; R Guardo; P Savard
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Annals of biomedical engineering     Volume:  23     ISSN:  0090-6964     ISO Abbreviation:  Ann Biomed Eng     Publication Date:    1995 Jan-Feb
Date Detail:
Created Date:  1995-06-29     Completed Date:  1995-06-29     Revised Date:  2007-11-15    
Medline Journal Info:
Nlm Unique ID:  0361512     Medline TA:  Ann Biomed Eng     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  61-9     Citation Subset:  IM    
Affiliation:
Institut de génie Biomédical, Ecole Polytechnique, Montréal, Québec, Canada.
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MeSH Terms
Descriptor/Qualifier:
Cardiography, Impedance*
Evaluation Studies as Topic
Humans
Image Processing, Computer-Assisted
Models, Anatomic
Monitoring, Physiologic
Numerical Analysis, Computer-Assisted
Pulmonary Edema / diagnosis
Sensitivity and Specificity
Thorax / anatomy & histology*

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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