The Research Of AC Magnetic Field Measurement System In Tumors Hyperthermia

Supported by the National Natural Science Foundation of China , study on method of measurement about intermediate frequency magnetic field.The main contributions are as follows:The basic theory of hyperthermia treatment of tumors with AC magnetic field is introduced and the development of AC magnetic heating setup and measurement system of high-frequency and intense magnetic field for therapy is summarized.By analyzing the electromagnetic field theory , magnetic field measuring method and the characteristics of near-field electromagnetic fields, by referring to design method of AC magnetic fields measurement system, Process of design is divided to magnetic-field sensor designed and circuit design. The size,construction and convertible principle of the probe is deduce in detail with the math method,then the signal processing circuit of the sensor is design。 The sensor frequency character is emulated , the result has shown that the response of probe flat over the frequency range of interest.Magetic-field strength of tumor magnetic heating device has been measured with home-made magneic-field measurment system ,the result shows that magnetic-field strength in the central of atmosphere between magnetic poles distributes uniformly and increases with the rise of circuit ,magnetic-field strength out of atmosphere between magnetic poles attenuates rapidly.Applied the software ANSYS ,the static and harmonic magnetic analyseis were finished that the detailed distribution of electromagnetic field in The Magetic-field of tumor magnetic heating device was calculated,the result exactly agrees with what is measured with home-made probe.The design of AC magnetic field measurement system can measure intermediate frequency magnetic field, analysising to the strength and distribution of the working magnetic field, provided the precious data for the temperature plan system development.