Effect of mobile phone radiation on brain using wavelet energy

Abstract

The usage of mobile phone is increased exponentially in last few years. So frequent exposure of human body to electromaghetic radiation is a growing concern. Most of the studies using EEG, (Electroencephalo graph) concluded with contradictory results, since the signal is considered as linear. As the EEG signal is non linear, non linear methods are more suitable, so wavelet transform method is used. EEGs of 10 volunteers were recorded at rest and on exposure to radiofrequency (RF) emissions from mobile phones with different SAR by keeping phone at Cz and Auricle positions. Wavelet energy is calculated for all bands (δ, θ, α, β & γ) of EEG, using wavelet transform were used as feature parameter. In this paper, relative wavelet energy of all bands of EEG calculated, for hundred samples of length 128 is analyzed using statistical methods. It is assumed that each band exhibit a characteristic range of wavelet energy. Relative energy is calculated as ratio of energy for each band to total energy. Data set of relative wavelet energy is analyzed using student’s paired t- test. Null hypothesis is rejected with 95% confidence in all the cases. The data set of mean of normalised energy is analysed using ANOVA to verify the result. There is 100% rejection of the hypothesis. This shows that the samples behave as they are from different population. All the data of same subject were recorded in succession under same conditions, so it is evident that these changes in wavelet energy while using mobile phones demonstrates transformation in the activities of brain due to radiation.