Study On Steep Pulsed Magnetic Fields Generator For Tumor Treatment

So far, the technology of pulsed magnetic fields treating for malignant tumor is not mature enough, and its clinical observation is not satisfied yet. In order to explore malignant tumor treatment under steep pulsed magnetic fields, this paper developed a set of measurement device for steep pulsed magnetic fields and Helmholtz coil which can produce steep pulsed magnetic fields. Applied with these diveces, a lot of cell experiments were carried out, which accordingly proved the positive performance of steep pulsed magnetic fields in preventing proliferation of tumor cells.First of all, through theoretical calculation and analysis, simulation and actual function tests, this paper developed a set of Helmholtz coil which can produce steep pulsed magnetic fields. The details are namely as following: chose the better scheme meeting experiment requirement, based on theoretical analysis; analyzed the magnetic fields distribution inside the coil according to the simulation study on coil scheme model with the simulation software named FEMLAB; and then proceeded with further improvements on the developed coil with considering the experiment requirement. The practical testing results showed that this kind of coil can produce steep pulsed magnetic fields with rise time of 50ns. It has a larger uniform region, and has the extremely stable working performance.Secondly, according to Faraday electromagnetic induction law, this paper also developed a set of measurement device for steep pulsed magnetic fields, and calibrated it based on theoretic calculation. All results of theoretic calculation, simulation study and actual tests indicated that this device has wide frequency range of 400 kHz¹00MHz, high sensitivity of 700V/T and accuracy of 1×10^-6T, as well as excellent performance of EMI shielding.At last, with the steep pulsed magnetic fields generator in this paper, cell experiments were made using human hepatoma cells (Hep-G2). The preliminary results suggested that steep pulsed magnetic fields have good effects on preventing proliferation of tumor cells.All results of lab tests and medicine experiments showed that in this paper the developed coil for steep pulsed magnetic fields production, and device for steep pulsed magnetic fields measurement, can meet the demands of medicine experiment. Besides, it is also proved that steep pulsed magnetic fields have positive performance on tumor treatment, which built solid foundation for future study on malignant tumor treatment under steep pulsed magnetic fields.