How to extract the energy ratio from wavelet coefficient?

my PHD is about of epileptic seizure detection using discret wavelet transform.So to decompose the EEG signal into its sub-bands I choose the Daubechies of order 4 . I read an article and the writer said that we need to extract the energy ratio from

[kowshik Thopalli]

check this answer -https://www.mathworks.com/matlabcentral/answers/84998-wavelet-decomposition-of-a-signal?s_tid=answers_rc1-3_p3_MLT