Use of trapezoidal waves and complementary static fields incident on magnetic nanoparticles to induce magnetic hyperthermia for therapeutic cancer treatment

Magnetic hyperthermia for treatment of tumors would benefit greatly from increased heating of the superparamagnetic particles, coupled with reduced incident electromagnetic wave power. Previous micromagnetic simulations based on the Landau-Lifshitz-Gilbert equation with thermal fluctuations showed that the use of incident square waves greatly increases the normalized heat. Experimentally generating a square waveform may produce a trapezoidal waveform due to an inherent rise and fall time. It is found that the normalized heating power given by this wave shows a 30% improvement over the sinusoidal waveform for an anisotropy distribution of 20%. A static magnetic field can increase the effectiveness of a sinusoidal waveform, but gives little added benefit to the effectiveness of a square waveform.