Boverman Gregory, Kao Tzu-Jen, Isaacson David, Saulnier Gary J
Information Sciences Institute, University ofSouthern California, Arlington, VA, USA.
IEEE Trans Med Imaging. 2009 Jul;28(7):1073-82. doi: 10.1109/TMI.2009.2012892. Epub 2009 Jan 19.
Mathematical interest in electrical impedance tomography has been strong since the publication of CalderOn's foundational paper. This paper introduced the idea of applying external voltage patterns to a medium such that, assuming that the medium is sufficiently close to a constant admittivity, the reconstruction can be accomplished directly by inverse Fourier transform. Motivated by CalderOn's method, we have developed a variant of the algorithm which is applicable to the case of measurement on only a part of the boundary and on discrete electrodes. Here we determine voltage or current patterns to apply to the electrodes which optimally approximate CalderOn's special functions in the interior. Furthermore, in three dimensions and higher, CalderOn's method allows each point in Fourier space to be computed in a multiplicity of ways. We show that by making use of the inherent redundancy in our measurements, we can significantly improve the quality of the static images produced by our algorithm.
自卡尔德隆的基础论文发表以来,数学界对电阻抗断层成像的兴趣一直浓厚。该论文提出了向介质施加外部电压模式的想法,这样一来,假设介质足够接近恒定电导率,就可以通过傅里叶逆变换直接完成重建。受卡尔德隆方法的启发,我们开发了一种算法变体,它适用于仅在边界的一部分以及离散电极上进行测量的情况。在这里,我们确定要施加到电极上的电压或电流模式,这些模式能在内部最佳地逼近卡尔德隆的特殊函数。此外,在三维及更高维度中,卡尔德隆方法允许以多种方式计算傅里叶空间中的每个点。我们表明,通过利用测量中固有的冗余性,我们可以显著提高我们算法生成的静态图像的质量。