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Abstract: 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 300kHz. When the Ti-tube thickness was as low as 0.1mm, 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 0.3mm 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. [Copyright &y& Elsevier]

Abstract: The heat generation ability of needle-type materials was studied for the application of thermal coagulation therapy in an AC magnetic field. Although the Ti tube without the MgFe2O4 powder or Ti rod showed poor heat generation abilities in an AC magnetic field, the temperature was significantly increased by the presence of ferrite powder in the Ti tube. We confirmed using a computer simulation that the eddy loss of the Ti tube was increased by the enhanced magnetic flux density due to the ferrite powder in the Ti tube. The heat generation of the ferrite filled Ti tube was increased by utilization of the quenched MgFe2O4 powder from elevated temperature. The relative magnetic permeability of the quenched ferrite was enhanced with the decrease in the inverse ratio of the cubic spinel structure. The heat generation ability was increased with the increase in the relative magnetic permeability of the Ti tube with ferrite powder. The calculated joule loss based on the experimental results showed an agreement with those using the computer simulation. [ABSTRACT FROM AUTHOR]