Optimization of helical coil applicators for hyperthermia

Author

Hagmann, Mark J.

Author_Institution

Dept. of Electr. Eng., Florida Int. Univ., Miami, FL, USA

Volume

36

Issue

1

fYear

1988

fDate

1/1/1988 12:00:00 AM

Firstpage

148

Lastpage

150

Abstract

Numerical solutions were used to optimize helical coil applicators to maximize the ratio of axial heating to surface heating within coaxial muscle cylinders. It is shown that this optimization requires significantly larger values of pitch angle and frequency than any previously specified for experimental applicators. The maximum ratio of axial to surface heating is obtained with a linear helix defined to have a pitch angle of 90°. Calculated ratios of axial/surface heating with a linear helix are as large as 2.54 (at 352 MHz) for a muscle cylinder with a radius of 4 cm, and 1.26 (at 82 MHz) for one with a radius of 8 cm. The relationship of the linear helix applicator to the annual phased-array applicator and to the resonant cylindrical cavity applicator is discussed

Keywords

biomedical equipment; biothermics; radiation therapy; radiofrequency heating; 82 to 352 MHz; RF heating; UHF; VHF; axial heating; biomedical equipment; biothermics; coaxial muscle cylinders; frequency; helical coil applicators; hyperthermia; linear helix; optimization; pitch angle; surface heating; Applicators; Coaxial components; Coils; Dielectric losses; Heating; Hyperthermia; Muscles; Phased arrays; Radio frequency; Resonance;

fLanguage

English

Journal_Title

Microwave Theory and Techniques, IEEE Transactions on

Publisher

ieee

ISSN

0018-9480

Type

jour

DOI

10.1109/22.3495

Filename

3495