生物组织磁聚焦电导率成像原理及反演算法  

Focused magnetic fields conductivity tomography of biological tissue and its inverse algorithm

作　　者：傅林[1] 黄卡玛[1] 向胜昭[1] 

机构地区：[1]四川大学电子信息学院,四川成都610064

出　　处：《电波科学学报》2006年第2期249-254,共6页Chinese Journal of Radio Science

基　　金：国家杰出青年基金资助(No.60125102);高等学校博士点基金资助

摘　　要：生物组织磁聚焦电导率成像系统利用多圈螺旋电感线圈形成聚焦磁场激励和检测导电目标,达到了提高成像空间分辨率的目的。根据所推导的频率变化与分层生物组织电导率的关系,引入遗传算法对目标电导率进行反演优化计算,获得了充足的成像数据。对于给定的十层分层生物组织模型,反演优化所得电导率除最深层有较大偏差需要进行数据处理外,其余均与目标一致,成像数据非常可靠;成像速度为百毫秒数量级但是具有很大提高潜力。计算结果表明该方法能够有效地对生物组织进行分层媒质建模计算,进一步采取措施能够实现较高分辨率的实时成像。The focused magnetic fields conductivity tomography system employs planar spiral coil for generating the focused magnetic fields and induces eddy current inside the biological tissue which generates secondary magnetic fields and couples back the coil. The system can obtain the changes of inductance of coil by measuring variety of frequencies in oscillators. According to relationship between variations of frequencies of oscillators and conduetivities within stratified biological tissue, the conductivity and its distribution inside tissue may be calculated and optimized by using genetic algorithm, For given ten layered homogeneous biological tissue model, the results of optimization calculation are consistent with actual values but the errors are increased with the augmenting depth. In addition, the errors increased with errors of measurement. For a measurement point, once inversion time is 100 milliseconds and had a great improving potential. Meantime, the results indicates that the system is effective to reconstruct the conductivity of stratified biological tissue. Moreover, the system is able to realize real-time imaging by further work.

关 键 词：磁聚焦电导率成像 聚焦线圈 优化计算 遗传算法 

分 类 号：Q64[生物学—生物物理学]