Abstract: A deep-heating diathermy apparatus consisting of a hollow tube adapted to receive a part of the body, or other dielectric material to be treated. An rf coil coaxially surrounds the tube and is driven by an rf generator. The total wire length of the coil is approximately 0.7 to 1.3 (depending on specific electrical properties and volume of the treated material) times the wavelength of a basic driving frequency provided by the generator. The output of the generator is supplied to the coil via a 50-ohm coaxial cable and a matching impedance. The coil may be driven by frequencies corresponding to integral multiples of one-half the basic wavelength, to enable shifting the heat focus volume along the coil axis from the normal centered location on the axis produced by full-wave excitation.

Abstract: A direct contact microwave diathermy applicator consisting of a rectangular waveguide in which are secured two parallel Teflon dielectric loading slabs. This assembly is secured in a waveguide-coaxial cable adaptor, enabling the applicator to be energized from a microwave diathermy machine. The configuration of the applicator causes the tissue under treatment to exhibit approximately uniform heating patterns over a substantial portion of the treated tissue area and minimizes harmful scatter radiation. This uniform heating is particularly useful in effecting microwave induced hyperthermia treatment of cancer.