Hyperthermia by Local EM Heating and Local Conductivity Change

A study is made on the scheme of heating a local region of a biological body by utilizing an EM field and increasing the conductivity of the local region. It was found that when the frequency of the EM field is in the range of 1 to 100 MHz, the increase of the conductivity of the local region usually causes a decrease, instead of an increase, of the absorbed power in that local region. For a microwave EM field, there may exist an optimum conductivity for the local region to gain the most effective EM heating.