Biologically active compounds are classified according to their effect on ion channels, changes in membrane potential and ionic currents, and the frequency content of action potentials that the compound(s) evoke in excitable cells. The spectral density changes of such evoked membrane potential or action...http://www.google.com/patents/US6377057?utm_source=gb-gplus-sharePatent US6377057 - Classification of biological agents according to the spectral density signature of evoked changes in cellular electric potential
