Tumor Ablation System Modeling: Tissue and Virtual Generator

This example demonstrates the complex behavior of Radio Frequency - RF - Thermal-Electric Tissue Ablation. The model consists of a cylindrical segment of liver, shown here with slices removed for visualization purposes.  There are three sets of double pronged electrodes arranged in a hexagonal pattern around the target tissue which could be a tumor or other lesion.

The electrode array is driven by a virtual generator modeled with a user subroutine providing the full feedback loop where the generator responds to the changing tissue impedance as the tissue isablated.  Multiple digital generators were developed allowing the entire generator to be changed as desired to investigate the function of the device designs under multiple service conditions.

A wide range of variables can be studied as to their effects on the lesion including:

• Power on-time
• Power off-time
• Electrode pair sequence
• Generator power level
• Generator Design
  • Current Product
  • Competitor's Product
  • New Concepts
• Electrode geometric configuration

The Liver Tissue Material Model for the simulation included Thermal and Electrical properties that varied as a function of temperature.