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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
1
|
| pubmed:dateCreated |
1991-7-3
|
| pubmed:abstractText |
Scalp potentials generated by a concentrated electric source in the brain are very similar to potentials generated by an electric dipole at the source position. In this sense a concentrated source in the brain is modelled as an electric dipole. When the source is diffuse such a dipole which best approximates the scalp potential is called an optimal dipole. Its position is calculated by the Dipole Tracing Method based on a realistic head model with homogeneous electric conductivity. There are 2 major difficulties inherent in this method: (1) The low electric conductivity of the skull causes systematic shifts of the optimal dipole positions from the true positions of concentrated sources; (2) the optimal dipoles cannot specify diffuse source positions. The first difficulty is overcome by using the numerical correction obtained by comparing the known dipole positions generated within a human head with their optimal ones. The second difficulty is removed to a certain extent by comparing the optimal dipole positions obtained with the 1-dipole and 2-dipole models together with their dipolarity. We have obtained criteria for the validity of the dipole approximation and source concentration.
|
| pubmed:language |
eng
|
| pubmed:journal | |
| pubmed:citationSubset |
IM
|
| pubmed:status |
MEDLINE
|
| pubmed:issn |
0896-0267
|
| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:volume |
3
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
143-50
|
| pubmed:dateRevised |
2006-11-15
|
| pubmed:meshHeading | |
| pubmed:year |
1990
|
| pubmed:articleTitle |
Do optimal dipoles obtained by the dipole tracing method always suggest true source locations?
|
| pubmed:affiliation |
Department of Applied Electronics, Tokyo Institute of Technology, Yokohama, Japan.
|
| pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't
|