Hyperthermia is a cancer therapy that necrotizes cancerous tumors by means of heat. The soft-heating method is one type of hyperthermia in which a small elongated element is implanted inside the body. The element generates heat induced by high frequency magnetic field produced by an exciting coil allows the element to generate heat. The most heat is generated when the element's major axis is parallel to the direction of the magnetic field, but solenoid and spiral coils may be excited in a nearly constant direction. It is therefore difficult to heat efficiently using these coils. What is required is a coil that can excite the element efficiently without depending on the position and direction of the heat element. In this paper, we examine a multidirectional exciting coil. We have concluded that, in case of using orthogonal type coil, multidirectional magnetic fields can be generated by being driven each coil with current phase difference or with different frequencies.
