tailieunhanh - Recent Advances in Biomedical Engineering_2

Tham khảo sách 'recent advances in biomedical engineering_2', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 14 3-D MRI and DT-MRI Content-adaptive Finite Element Head Model Generation for Bioelectomagnetic Imaging Tae-Seong Kim and Won Hee Lee Kyung Hee University Department of Biomedical Engineering Republic of Korea 1. Introduction One of the challenges of the 21st century is to understand the functions and mechanisms of the human brain. Although the complexity of deciphering how the brain works is so overwhelming the electromagnetic phenomenon happening in the brain is one aspect we can study and investigate. In general this phenomenon of electromagnetism is described as the electrical current produced by action potentials from neurons which are reflected as the changes in electrical potential and magnetic fields Baillet et al. 2001 . These electromagnetic fields of the brain are generally measured with electroencephalogrm EEG and magnetoencephalogram MEG that are actively used for bioelectromagnetic imaging of the human brain . inverse solutions of EEG and MEG . In order to investigate the electromagnetic phenomenon of the brain the human head is generally modelled as an electrically conducting medium and various numerical approaches are utilized such as boundary element method He et al. 1987 Hamalainen Sarvas 1989 Meijs et al. 1989 finite difference method Neilson et al. 2005 Hallez et al. 2008 and finite element method Buchner et al. 1997 Marin et al. 1998 Kim et al. 2002 Lee et al. 2006 Wolters et al. 2006 Zhang et al. 2006 Wendel et al. 2008 to solve the bioelectromagnetic problems . forward solutions of EEG and MEG . Among these approaches the finite element method FEM or analysis FEA is known as the most powerful and realistic method with increasing popularity due to i readily available computed tomography CT or magnetic resonance MR images where geometrical shape information can be derived ii recent developments in imaging physical properties of biological tissue such as electrical Kim et al. 2009 or thermal conductivity which can be incorporated in