Publication: In vivo estimation of head tissue conductivities using bound constrained optimization
2
0
Issued Date
2019
Resource Type
File Type
application/pdf
ISSN
906964
Other identifier(s)
2-s2.0-85064503315
Rights Holder(s)
มหาวิทยาลัยศรีนครินทรวิโรฒ
Bibliographic Citation
Annals of Biomedical Engineering. Vol 47, No.7 (2019), p.1575-1583
Suggested Citation
Ouypornkochagorn T., Ouypornkochagorn S. In vivo estimation of head tissue conductivities using bound constrained optimization. Annals of Biomedical Engineering. Vol 47, No.7 (2019), p.1575-1583. doi:10.1007/s10439-019-02254-9 Retrieved from: https://hdl.handle.net/20.500.14740/5259
Author(s)
Abstract
The conductivity of head tissues was noninva-sively estimated using electrical impedance tomography technique. Instead of using conventional unconstrained optimization method to estimate the conductivities, a constrained method with the scaled-logistic function was employed to improve the very high sensitivity of the skull region resulting in accuracy and robustness improvement. Estimation of five conductivities i.e. scalp, skull, cerebrospinal fluid (CSF), grey matter (GM), and white matter (WM) conductivity was investigated by simulation on random and low-value initial guesses. Simulation results showed that the performance of the unconstrained method depended directly to the difference between the exact skull conductivity value and the initial guess value of the skull conductivity. However, the approached constrained method was independent of the guess selection. It can reduce the sensitivity of the skull region by 126 times and reduce the condition number of the sensitivity matrix by 13–17 times. The estimation resulted in only positive and in-range of reported conductivity values. The estimation error of the skull conductivity decreased by 15% and the robustness increased by 2 times. However, the estimation of the CSF, the WM, and the GM may be not reliable due to the very low sensitivity of these regions in both methods. © Springer. All rights reserved.
Subject(s)
Cerebrospinal fluid
Electric impedance
Electric impedance measurement
Electric impedance tomography
Number theory
Tissue
Bio-impedance
Bound constrained optimization
Cerebro spinal fluids
Electrical impe dance tomography (EIT)
Electrical impedance tomography
Initial guess
Tissue conductivity
Unconstrained optimization
Constrained optimization
Article
Cerebrospinal fluid
Computer assisted impedance tomography
Conductance
Gray matter
Human tissue
In vivo study
Scalp
Simulation
Skull
White matter
Adult
Biological model
Computer simulation
Human
Impedance
Adult
Cerebrospinal Fluid
Computer Simulation
Electric Impedance
Gray Matter
Humans
Models, Biological
Scalp
Skull
White Matter
Electric impedance
Electric impedance measurement
Electric impedance tomography
Number theory
Tissue
Bio-impedance
Bound constrained optimization
Cerebro spinal fluids
Electrical impe dance tomography (EIT)
Electrical impedance tomography
Initial guess
Tissue conductivity
Unconstrained optimization
Constrained optimization
Article
Cerebrospinal fluid
Computer assisted impedance tomography
Conductance
Gray matter
Human tissue
In vivo study
Scalp
Simulation
Skull
White matter
Adult
Biological model
Computer simulation
Human
Impedance
Adult
Cerebrospinal Fluid
Computer Simulation
Electric Impedance
Gray Matter
Humans
Models, Biological
Scalp
Skull
White Matter
