Dear all, I need to know the natural (resonance) frequency of the brain, blood vessels and the heart. I will appreciate very much your help. Thank you, Naser Khaled Nawayseh The University of Sheffield Dept. of Automatic Control and Systems Engineering Mappin Street, Sheffield S1 3JD Great Britain Tel: +44(0)114-222-5608 (Office) %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%