Title :
An equivalent current source model and Laplacian weighted minimum norm current estimates of brain electrical activity
Author :
He, Bin ; Yao, D. ; Lian, Jie ; Wu, D.
Author_Institution :
Dept. of Bioeng., Chicago Univ., IL, USA
fDate :
4/1/2002 12:00:00 AM
Abstract :
We have developed a method for estimating the three-dimensional distribution of equivalent current sources inside the brain from scalp potentials. Laplacian weighted minimum norm algorithm has been used in the present study to estimate the inverse solutions. A three-concentric-sphere inhomogeneous head model was used to represent the head volume conductor. A closed-form solution of the electrical potential over the scalp and inside the brain due to a point current source was developed for the three-concentric-sphere inhomogeneous head model. Computer simulation studies were conducted to validate the proposed equivalent current source imaging. Assuming source configurations as either multiple dipoles or point current sources/sinks, in computer simulations we used our method to reconstruct these sources, and compared with the equivalent dipole source imaging. Human experimental studies were also conducted and the equivalent current source imaging was performed on the visual evoked potential data. These results highlight the advantages of the equivalent current source imaging and suggest that it may become an alternative approach to imaging spatially distributed current sources-sinks in the brain and other organ systems.
Keywords :
Laplace transforms; brain models; electroencephalography; inverse problems; medical image processing; visual evoked potentials; Laplacian weighted minimum norm current; brain electric source imaging; brain electrical activity; closed-form solution; equivalent current source model; equivalent dipole source imaging; forward problem; head volume conductor; high-resolution EEG; inverse solutions; scalp potentials; three-concentric-sphere inhomogeneous head model; three-dimensional distribution; visual evoked potential; Brain modeling; Closed-form solution; Computer simulation; Conductors; Electric potential; Head; Humans; Image reconstruction; Laplace equations; Scalp; Algorithms; Brain; Computer Simulation; Electric Conductivity; Electroencephalography; Electrophysiology; Evoked Potentials; Feasibility Studies; Humans; Models, Neurological; Scalp; Skull;
Journal_Title :
Biomedical Engineering, IEEE Transactions on