Abo Bibliothek: Guest

ISSN Online: 2377-424X

ISBN Print: 0-89116-299-2

International Heat Transfer Conference 7
September, 6-10, 1982, Munich, Germany

THERMAL STRESSES IN SOFT TISSUES INDUCED BY ELECTROMAGNETIC AND ULTRASONIC DIATHERMY

Get access (open in a dialog) DOI: 10.1615/IHTC7.4160
pages 571-576

Abstrakt

Timewise variation of thermal stresses and tissue displacement in a plane skin-fat-muscle combination induced by non-invasive methods of heating by electromagnetic (EM) and ultrasonic (US) radiation is theoretically studied. All mechanisms of heat dissipation such as capillary blood cooling, metabolic heat production and heat diffusion are taken into account. The uncoupled quasi-static theory is employed in the temperature-displacement analysis. The effects of wave frequency, power input, ambient conditions, tissue geometry and core conditions on normal stresses and displacement are determined It is disclosed that radiation heating induces maximum displacement in the musculature at the location of transition of normal stresses from tension to compression. An abrupt increase in blood perfusion rate initiated at a critical tissue temperature induces a sharp increase in the magnitude of both the local tissue displacement and normal stresses. A microwave frequency of 433 MHz yeilds the lowest maximum tissue displacement and normal stresses in applications.