Temperature-dependent dielectric properties of liver tissue measured during thermal ablation: toward an improved numerical model.

The development of microwave tumor ablation devices depends largely on numerical simulations of antenna characteristics and transient electromagnetic heating. However, without an adequate tissue model simulation predictions can vary widely from experimental results. In this study, tissue dielectric properties are measured to capture changes induced by temperature, cellular makeup and water content during thermal ablation. Measurements made using this technique agree closely with previous measurements for temperatures up to 50 degrees C, but both relative permittivity and conductivity decrease by as much as 50 percent when temperatures approach 100 degrees C.