磁疗用圆片永磁磁源空间磁感强度理论值与实测值分析

摘要

目的:在磁疗研究中,磁源空间磁感强度的量值可以通过相关的理论计算来完成,但由于各种原因磁源空间磁感强度的实际值会与理论值存在一定的差别.本文以磁疗用圆片永磁磁源为研究对象,探讨了磁源空间磁感强度理论值与实测值的关系,为磁疗的准确磁场定量提供了依据.方法:取极面中心磁感强度名义值为100 mT磁源30片(沿磁源轴线方向充磁),筛选出N、S两极面中心磁感强度差别较小的磁源,依据其极面中心磁感强度数值,采用有限元数值计算方法进行磁源空间磁场理论分析与计算,得出磁感强度的理论计算值;同时设计测量装置进行磁源空间磁场测量,得出与理论计算位置对应点的实测值,分析理论值与测量值的差别.结果:所选磁源空间磁感强度理论值与测量值总体变化趋势一致,在磁源N、S极面中心连线(轴线)上数值吻合情况最好,其它大部分位置点误差率低于30％;磁源倒角所对方向误差较大,误差率可超过100％.结论:由于磁场空间磁感强度理论计算值与实测值之间的差别是系统误差,因此磁源空间磁感强度理论值可用于初步指导磁疗定量研究.但要准确掌握磁源各空间位置的磁感强度必须进行实际测量或对理论计算结果进行修正.%Objective: In magnetic therapy studies, magnetic induction values of magnetic sources can be got through relevant theoretical calculation, but there are certain differences between theoretical values and actual values of space magnetic induction of magnetic sources due to various reasons. This study used circular permanent magnetic sources as research objects, to investigate the consistency of theoretical values and measured values of space magnetic induction of circular permanent magnetic sources to provide basis for quantitative application of magnetic sources. Methods: Taking 30 circular magnetic sources with nominal value of magnetic induction 100mT in pole center, and selected those which magnetic inductions of N, S pole center had smaller differences, On the basis of the polar center magnetic induction values, using finite element numerical calculation method to finish theoretical analysis and magnetic field calculation of magnetic sources, got theoretical values of magnetic induction; At the same time, designed measurement device for spatial magnetic field measurement of magnetic sources, got the measured values corresponding to the theoretical calculation point, analyzed the differences of theoretical values and measured values. Results: The measured values and theory values of selected space magnetic induction magnetic sources had the same trend. In the N, S polar center axis of magnetic sources numerical anastomosis situation was the best, in other positions the error rate was lower than 30%; in direction of magnetic source chamfering the error was bigger, the error rate could be more than 100%. Conclusions: The differences of theory calculated values and measured values of magnetic field induction are system errors, so the theoretical values of space magnetic induction can be used for preliminary guidance of quantitative study of magnetic therapy. But to grasp the magnetic induction of space position of magnetic source accurately, it must need practical measurement or the theoretical calculation result be fixed.