Design of Alternating Magnetic Field Excitation System Based on Magnetic Nanometer Temperature Measurement
SU Rijian
MENG Deguang
DU Zhongzhou
HOU Dengpan
Abstract：The method of the temperature measurement based on magnetic nanoparticles in hyperthermia is expected to solve the problem that the temperature cannot be measured accurately.This paper analyzes the problems such as low homogeneity of magnetic field,low signal to noise ratio,load impedance in the application of the method of the temperature measurement base magnetic nanoparticles.Firstly,Helmholtz coil is proposed as the excitation part for generating the AC magnetic field by careful analysis of signal chain in the AC magnetic field system from three aspects:theoretical analysis,analogue simulation and actual measurement.Secondly the nine-order elliptic passive filter is designed for solving the problems of low signal-to-noise ratio and the test result meets design requirement that the signal-to-noise is 100dB.Lastly,according to impedance matching theories,the series resonant circuit is used for solving the impedance mismatch.The test result is that the magnetic field strength is 20Gs.In the meantime,the sampling resistor,which is a power resister installed in series to the load circuit for monitoring the excitation current of the Helmholtz coils and negative feedback control algorithm,was used to stabilize the exciting magnetic field.
Keywords：magnetic nanoparticlesHelmholtzninth order elliptic filterseries resonance
Publication Date：2017-04-02
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：5( 182-185,202 )