Abstract:
:The increasing use of EIT in clinical research on severely ill lung patients requires a clarification of the influence of pathologic impedance distributions on the validity of the resulting tomograms. Significant accumulation of low-conducting air (e.g. pneumothorax or emphysema) or well-conducting liquid (e.g. haematothorax or atelectases) may conflict with treating the imaging problem as purely linear. First, we investigated the influence of stepwise inflation and deflation by up to 300 ml of air and 300 ml of Ringer solution into the pleural space of five pigs on the resulting tomograms during ventilation at constant tidal volume. Series of EIT images representing relative impedance changes were generated on the basis of a modified Sheffield back projection algorithm and ventilation distribution was displayed as functional (f-EIT) tomograms. In addition, a modified simultaneous iterative reconstruction technique (SIRT) was applied to quantify the resistivity distribution on an absolute level scaled in Omega m (a-EIT). Second, we applied these two EIT techniques on four intensive care patients with inhomogeneous air and fluid distribution and compared the EIT results to computed tomography (CT) and to a reference set of intrathoracic resistivity data of 20 healthy volunteers calculated by SIRT. The results of the animal model show that f-EIT based on back projection is not disturbed by the artificial pneumo- or haematothorax. Application of SIRT allows reliable discrimination and detection of the location and amplitude of pneumo- or haematothorax. These results were supported by the good agreement between the electrical impedance tomograms and CT scans on patients and by the significant differences of regional resistivity data between patients and healthy volunteers.
journal_name
Physiol Measjournal_title
Physiological measurementauthors
Hahn G,Just A,Dudykevych T,Frerichs I,Hinz J,Quintel M,Hellige Gdoi
10.1088/0967-3334/27/5/S16subject
Has Abstractpub_date
2006-05-01 00:00:00pages
S187-98issue
5eissn
0967-3334issn
1361-6579pii
S0967-3334(06)11250-2journal_volume
27pub_type
杂志文章abstract::During voluntary contractions in humans, the subcutaneous tissues between surface electrodes and active motor units have been shown to attenuate surface electromyographic (EMG) signal amplitude. The purpose of this investigation was to examine the relationship between adipose tissue thickness and the electromechnical ...
journal_title:Physiological measurement
pub_type: 临床试验,杂志文章
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journal_title:Physiological measurement
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pub_type: 杂志文章
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更新日期:2010-12-01 00:00:00
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doi:10.1088/1361-6579/ab5154
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journal_title:Physiological measurement
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更新日期:2007-08-01 00:00:00
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pub_type: 杂志文章,评审
doi:10.1088/1361-6579/aa5fca
更新日期:2017-05-01 00:00:00
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pub_type: 杂志文章
doi:10.1088/1361-6579/aba07b
更新日期:2020-08-11 00:00:00
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journal_title:Physiological measurement
pub_type: 杂志文章
doi:10.1088/0967-3334/27/1/005
更新日期:2006-01-01 00:00:00
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pub_type: 杂志文章
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pub_type: 临床试验,杂志文章
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更新日期:2017-03-01 00:00:00
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pub_type: 杂志文章
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journal_title:Physiological measurement
pub_type: 杂志文章
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更新日期:2014-08-01 00:00:00
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journal_title:Physiological measurement
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更新日期:1999-08-01 00:00:00
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更新日期:2014-11-01 00:00:00
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pub_type: 杂志文章
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pub_type: 临床试验,杂志文章
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