Study of brain dynamics under mobile phone radiation using various fractal dimension methods

摘要

The electroencephalogram (EEG) is a record of the oscillations of brain electric potentials. The EEG provides a convenient window on the mind, revealing synaptic action that strongly co-relate with brain state. Fractal dimension, measure of signal complexity can be used to characterize the physiological conditions of the brain. As the EEG signal is non linear, non stationary and noisy, non linear methods will be suitable for the analysis. In this paper various methods of fractal dimension analysis especially Higuichi's fractal method, Katz, and k-NN algorithms were applied to find the fractal dimension of EEG. The main attraction of fractal geometry stems from its ability to describe the irregular shape of natural features as well as other complex objects that traditional Euclidean geometry fails to analyse‥ EEGs of 5 volunteers were recorded at rest and on exposure to radiofrequency (RF) emissions from mobile phones having different SAR values. Mobiles were positioned near the ears and then near the cz position. Fractal dimensions for all conditions are calculated using three algorithms. The result shows that there are some changes in the FD while using mobile phone. The change in FD of the signal varies from person to person. The changes in FD show the variations in EEG signal while using mobile phone, which demonstrate transformation in the activities of brain due to radiation.