High-frequency induction heating of Ti-coated mild steel rod for minimally invasive ablation therapy of human cancer

For application as a novel ablation therapy of human cancer, the heating property of a Ti-coated mild steel rod was studied in an AC magnetic field at 300 kHz. When the Ti-tube thickness was as low as 0.1 mm, the specimen, when placed parallel to the magnetic flux direction (θ=0°), exhibited a significant increase in temperature; however, its value gradually decreased with the increasing Ti thickness. In computer simulation images, the high magnetic flux concentration and concurrent large current density were observed around the interface between the mild steel rod and the Ti-tube. The heating property was drastically different at the three inclination angles (θ=0°, 45°, and 90°) to the magnetic flux direction. However, the effect of the inclination angle was markedly reduced in the mild steel rod surrounded by a 0.3 mm thick Ti-tube, suggesting that the non-oriented heating property will be achieved for the prototype ablation needle coated with a Ti layer having the optimum thickness.

► Heating property of a ferromagnetic mild steel rod in AC magnetic fields.
► Drastically different heating property is obtained owing to the Ti layer thickness.
► Computer simulation images showing the mechanism of heating property.
► Effect of the inclination angle is reduced using an optimum Ti layer thickness.
► It is expected that we can fabricate a non-oriented ablation needle for clinical use.