Development of steep pulsed magnetic fields generator for tumor treatment

In order to study a new tumor treatment method using steep pulsed magnetic fields (SPMF), this paper developed a SPMF generator by means of the integration of pulsed power technology and modern power electronics technology. After a brief introduction of basic principle of SPMF generator, steep pulse formation circuit and Helmholtz coils, two main parts of SPMF generator, were discussed in detail, especially on design techniques. The peak value, width and repeat rate of the output SPMF waveform could be adjusted independently in the range of 0~1 mT, 160 ns~55μs and 1Hz~1 kHz, respectively. The rise time was shortened to 70-220 nanoseconds by means of choosing quickly operating switch and reducing circuit stray inductance. Magnetic field distribution uniformity was improved via designing better geometrical structure of Helmholtz coils. This research laid the foundations for further experiment and mechanism research of tumor treatment utilizing SPMF.