Figure 5
From: Theoretical modeling for radiofrequency ablation: state-of-the-art and challenges for the future
Example of hypothetic behavior for the electrical conductivity (σ) of a biological tissue considering a thermal level of ≈70°C as first threshold of the irreversible behavior, such as that experimentally observed by Pop et al [82]. In addition, the dotted line represents the relation between σ and temperature once a second thermal threshold (≈90°C) has occurred. This second level is associated with a high degree of tissue desiccation, and thus a significant increase in the electrical impedance, as has been experimentally observed [134] (i.e. a lower value of σ). The real situation is probably more complex, since the thresholds are not simply thermal levels but levels of a tissue damage function. For the y-axis the units of σ are arbitrary.