Effect of Water-Cooled Loop Monopole Antenna on Microwave Ablation Efficiency

This work compares the effect of a monopole antenna without cooling unit on a biological tissue and a monopole antenna with cooling unit. Computer simulation was done using a computer software named COMSOL MultiphysicsTM, input power was varied from 10W to 120W, with an interval of 10W, at different times, from 60s to 120s at an interval of 60s. It was observed that the diameter of the lowest power (20W) decreased by -17.2% at 5mins, the length decreased by -32.9% and aspect ratio for the two antennas increased by 23.40%. For medium power (60W), at 5mins, the diameter decreased by -9.89%, length decreased by -37.9%, and aspect ratio decreased by 45.24%. The p-value obtained from diameter for low power showed no significant difference for ablation without water cool (p > 0.005), but showed significant difference with water cool (p < 0.005), diameter for medium power showed no significant difference, p > 0.005 in both simulations, there was no statistically significant difference in the diameter for high power (110W and 120W) for both simulations, p-value > 0.005. The result showed that inclusion of cooling unit reduced backward heating of microwave antenna, ablation length, and ablation diameter of simulated tissue.