Brain Power, Time-harmonic And Head Of Media Study On The Influence Of Brain Potentials

In the paper,the electrophysiological mechanisms of production of brain electromagnetic field and the structures and functions of neuron and synapse are induced.The ions which stay in and out of neuron move through neuronal membrane, and neuronal electric current is produced.The current is transferred among all neurons through the synapse.The researching meanings,methods,foreground,actuality and deficiency are amply induced and my work is directed against the researching deficiency.The distributions of electric potentials in homogeneous dielectric sphere and inhomogeneous three-layer dielectric sphere produced by dipole and the influences on potentials caused by time-harmonic property and dielectric property are researched, based on the research of the forward problem of EEG The work is focused on the following several aspects:(1) A modal of time-harmonic equivalent current dipole is proposed to simulate EEG source and an isotropic dielectric sphere modal is built for researching into the influences produced by the time-harmonic property of dipole and the dielectric property of medium.The brain electromagnetic field is described by Maxwell equations in the electroquasistatic condition.(2) On the surface of homogeneous dielectric sphere,the real and imaginary parts of the electric potentials produced by the dipole are calculated respectively.The numerical results and the figures what describe the distributions of electric potentials are given.(3) On the surface of every layer of inhomogeneous three-layer dielectric sphere, the real and imaginary parts of the electric potentials produced by the dipole are calculated respectively.The numerical results and the figures what describe the distributions of electric potentials are given,too.(4) On the surface of Debye dielectric sphere,the real and imaginary parts of the electric potentials produced by the dipole are calculated respectively.The responding relations of potential to time and frequency are calculated and discussed respectively. The numerical results and the figures what describe the distributions of electric potentials are given.The calculational results show that the influences exist certainly on potential produced by time-harmonic property of EEG source and dielectric property of brain when frequency equals or exceeds 50Hz.