The human tissue cells in the spontaneous production of a very weak biological activity, the use of electrodes on the scalp will be installed on the cell's electrical activity, and after the EEG amplification recorded to get a certain waveform, amplitude, frequency and phase of the graphics, curve, that is, the eeg. When the pathological changes of brain tissue occur, this curve will change accordingly, so as to provide evidence for clinical diagnosis and treatment of brain and nervous system diseases, such as the infection of central nervous system, intracranial tumor and chronic diseases, cerebrovascular disease, brain injury and epilepsy.
When the neuron is affected by genetic, pathological, electrochemical or drug stimulation, the cell membrane is destroyed, and the action potential is generated. The local action potential will destroy the balance of the cell membrane. This series of biochemical and physical processes, which constitute the action potential in neurons and nerve cell membrane, generate a brain electrical signal, and its amplitude range is 10-100 ~ V.