Tripas: A Triapplicator System with Relocatable ‘Hot Spot’ at Tissue Depth

  • Haim I. Bicher
  • Samuel A. Afuwape
  • Ralph S. Wolfstein
  • Duane F. Bruley
  • Kenneth Reesman
Part of the Advances in Experimental Medicine and Biology book series (AEMB, volume 267)


Solving the problem of heat focusing and standardization of the clinical application of hyperthermia requires a mathematical prediction model. The model should include the medium constitutive parameter, and be able to predict positioning of the microwave applicators to optimize treatment planning and provide for reproducible treatment set-up. We present a configuration of 3 applicators subtended by an equilateral triangle in order to target and relocate a ‘hot spot’ for improved treatment of deep tumors. A simple geometric analysis is illustrated. The microwave beam absorption profile, from the three power sources, was obtained from phantom studies depicting the radiative heat pattern for the triapplicator system (TRIPAS). A complex mathematical model was developed to demonstrate interaction of the beams in the medium.

It was observed empirically that under coherent propagation in the near field electromagnetic (EM) waves tend to add at the center, while varying the propagation axial focal length caused a relocation of the summing focal points.

Mathematical prediction correlated very well with the phantom studies. SAR values above 100 W/kg were achieved at 12.5 cm phantom depth, creating a relocatable ‘hot spot’ at the concentric foci of the 3 air cooled horn microwave applicators operating at 300 MHz.


Constitutive Parameter Specific Absorption Rate Effective Wavelength Circular Segment Polarize Plane Wave 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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Copyright information

© Plenum Press, New York 1990

Authors and Affiliations

  • Haim I. Bicher
    • 1
  • Samuel A. Afuwape
    • 1
  • Ralph S. Wolfstein
    • 1
  • Duane F. Bruley
    • 1
  • Kenneth Reesman
    • 1
  1. 1.Valley Cancer InstitutePanorama CityUSA

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