SELECTIVE HEATING BY SHORT RADIO WAVES AND ITS APPLICATION TO ELECTROTHERAPY

Abstract

In the first part of the paper the theoretical basis of the formulas, given in a previous communication, for the generation of heat in a poorly conducting dielectric which is placed in the field of a high-frequency oscillator, is examined in some detail. Its application to the complicated case met with in medical "radiothermy" is made and it is shown that the analysis applies with satisfactory accuracy to this case, though not to that of electrode diathermy. Prediction of the "selective" effect is possible from a knowledge of the characteristic electrical constants of the body-substances at high frequencies, and by proper choice of wave-length the heating of a particular part might be favored over that of neighboring parts.In the second part of the paper, experimental work is described which carries verification of the formulas to shorter wave-lengths. Experiments on the heating of meat demonstrate the selective effect and its dependence upon wave-length. The heating of such substances as liver, heart, and the different parts of an egg, are examined experimentally as examples of the various determining factors that are involved.The theoretical explanation of the effects is considered satisfactory and further developments depend upon the results of in viva experiments with shorter wavelengths than those at present in general use.