EEG/MEC error bounds for a static dipole source with a realistic head model

2001 ◽  
Vol 49 (3) ◽  
pp. 470-484 ◽  
Author(s):  
C.H. Muravchik ◽  
A. Nehorai

2000 ◽  
Vol 39 (02) ◽  
pp. 110-113 ◽  
Author(s):  
C. Muravchik ◽  
O. Bria ◽  
A. Nehorai

Abstract:This work presents the background and derivation of Cramér-Rao bounds on the errors of estimating the parameters (moment and location) of a dynamic current dipole source using data from electro- and magneto-encephalography. A realistic head model, based on knowledge of surfaces separating tissues of different conductivities, is used.



NeuroImage ◽  
2001 ◽  
Vol 13 (6) ◽  
pp. 970
Author(s):  
Deborah E. Bentley ◽  
Paula D. Youell ◽  
Anthony K.P. Jones


Epilepsia ◽  
2000 ◽  
Vol 41 (1) ◽  
pp. 71-80 ◽  
Author(s):  
G. Herrendorf ◽  
B. J. Steinhoff ◽  
R. Kolle ◽  
J. Baudewig ◽  
T. D. Waberski ◽  
...  


2003 ◽  
Vol 114 (6) ◽  
pp. 1069-1078 ◽  
Author(s):  
Katsuhiro Kobayashi ◽  
Harumi Yoshinaga ◽  
Makio Oka ◽  
Yoko Ohtsuka ◽  
Jean Gotman


PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e4061 ◽  
Author(s):  
Awais Munawar Qureshi ◽  
Zartasha Mustansar

In this paper, we have presented a microwave scattering analysis from multiple human head models. This study incorporates different levels of detail in the human head models and its effect on microwave scattering phenomenon. Two levels of detail are taken into account; (i) Simplified ellipse shaped head model (ii) Anatomically realistic head model, implemented using 2-D geometry. In addition, heterogenic and frequency-dispersive behavior of the brain tissues has also been incorporated in our head models. It is identified during this study that the microwave scattering phenomenon changes significantly once the complexity of head model is increased by incorporating more details using magnetic resonance imaging database. It is also found out that the microwave scattering results match in both types of head model (i.e., geometrically simple and anatomically realistic), once the measurements are made in the structurally simplified regions. However, the results diverge considerably in the complex areas of brain due to the arbitrary shape interface of tissue layers in the anatomically realistic head model.After incorporating various levels of detail, the solution of subject microwave scattering problem and the measurement of transmitted and backscattered signals were obtained using finite element method. Mesh convergence analysis was also performed to achieve error free results with a minimum number of mesh elements and a lesser degree of freedom in the fast computational time. The results were promising and the E-Field values converged for both simple and complex geometrical models. However, the E-Field difference between both types of head model at the same reference point differentiated a lot in terms of magnitude. At complex location, a high difference value of 0.04236 V/m was measured compared to the simple location, where it turned out to be 0.00197 V/m. This study also contributes to provide a comparison analysis between the direct and iterative solvers so as to find out the solution of subject microwave scattering problem in a minimum computational time along with memory resources requirement.It is seen from this study that the microwave imaging may effectively be utilized for the detection, localization and differentiation of different types of brain stroke. The simulation results verified that the microwave imaging can be efficiently exploited to study the significant contrast between electric field values of the normal and abnormal brain tissues for the investigation of brain anomalies. In the end, a specific absorption rate analysis was carried out to compare the ionizing effects of microwave signals to different types of head model using a factor of safety for brain tissues. It is also suggested after careful study of various inversion methods in practice for microwave head imaging, that the contrast source inversion method may be more suitable and computationally efficient for such problems.



Sign in / Sign up

Export Citation Format

Share Document