Optimum Receiver Array Design for Magnetic Induction Tomography

Magnetic induction tomography (MIT) is an imaging modality that aims at mapping the distribution of the electrical conductivity inside the body. Eddy currents are induced in the body by magnetic induction and the resulting fields are measured by an array of receiver coils. In MIT, the location of the receivers affects the quality of the image reconstruction. In this paper, a fast deterministic algorithm was applied to obtain optimum receiver array designs for a given specific excitation. The design strategy is based on the iterative exclusion of receiver locations, which yield poor conductivity information, from the space spanning all possible locations until a feasible design is reached. The applicability of ldquoregionally focusedrdquo MIT designs that increase the image resolution at a particular region was demonstrated. Currently used design geometries and the corresponding reconstructed images were compared to the images obtained by optimized designs. The eigenvalue analysis of the Hessian matrix showed that the algorithm tends to maintain identical conductivity information content sensed by the receivers. Although the method does not guarantee finding the optimum design globally, the results demonstrate the practical usability of this algorithm in MIT experimental designs.

[1]  Andrew Curtis,et al.  Optimal design of focused experiments and surveys , 1999 .

[2]  A. Adler,et al.  A measure of the information content of EIT data , 2008, Physiological Measurement.

[3]  John R. Mortarelli A Generalization of the Geselowitz Relationship Useful in Impedance Plethysmographic Field Calculations , 1980, IEEE Transactions on Biomedical Engineering.

[4]  Hermann Scharfetter,et al.  Planar gradiometer for magnetic induction tomography (MIT): theoretical and experimental sensitivity maps for a low-contrast phantom. , 2004, Physiological measurement.

[5]  P ? ? ? ? ? ? ? % ? ? ? ? , 1991 .

[6]  H Griffiths,et al.  A primary field compensation scheme for planar array magnetic induction tomography. , 2004, Physiological measurement.

[7]  Per Christian Hansen,et al.  Rank-Deficient and Discrete Ill-Posed Problems , 1996 .

[8]  Patricia Brunner,et al.  Reconstruction of the shape of conductivity spectra using differential multi-frequency magnetic induction tomography , 2006, Physiological measurement.

[9]  Vladimir A. Cherepenin,et al.  Progress in Realization of Magnetic Induction Tomography , 1999 .

[10]  O Dössel,et al.  Design and performance of a planar-array MIT system with normal sensor alignment. , 2005, Physiological measurement.

[11]  Anthony Lomax,et al.  A deterministic algorithm for experimental design applied to tomographic and microseismic monitoring surveys , 2004 .

[12]  Nevzat G. Gencer,et al.  Electrical conductivity imaging via contactless measurements: an experimental study , 2003, IEEE Transactions on Medical Imaging.

[13]  Martin Schweiger,et al.  MULTILEVEL PRECONDITIONING FOR 3D LARGE-SCALE SOFT-FIELD MEDICAL APPLICATIONS MODELLING , 2006 .

[14]  Joaquim Ferreira,et al.  An overview of electromagnetic inductance tomography: Description of three different systems , 1996 .

[15]  O Dössel,et al.  A comparison of sensors for minimizing the primary signal in planar-array magnetic induction tomography. , 2005, Physiological measurement.

[16]  G. Temple Static and Dynamic Electricity , 1940, Nature.

[17]  Thomas M. Cover,et al.  Elements of Information Theory , 2005 .

[18]  Hermann Scharfetter,et al.  A new type of gradiometer for the receiving circuit of magnetic induction tomography (MIT). , 2005, Physiological measurement.

[19]  Patricia Brunner,et al.  Solution of the inverse problem of magnetic induction tomography (MIT) , 2005, Physiological measurement.

[20]  Hermann Scharfetter,et al.  Biological tissue characterization by magnetic induction spectroscopy (MIS): requirements and limitations , 2003, IEEE Transactions on Biomedical Engineering.

[21]  Nevzat G. Gencer,et al.  Electrical conductivity imaging via contactless measurements , 1999, IEEE Transactions on Medical Imaging.

[22]  H Griffiths,et al.  Magnetic Induction Tomography: A Measuring System for Biological Tissues , 1999, Annals of the New York Academy of Sciences.

[23]  A Korjenevsky,et al.  Magnetic induction tomography: experimental realization. , 2000, Physiological measurement.

[24]  H. Lackner,et al.  Magnetic induction tomography: hardware for multi-frequency measurements in biological tissues. , 2001, Physiological measurement.

[25]  N. G. Gencer,et al.  Forward problem solution for electrical conductivity imaging via contactless measurements. , 1999, Physics in medicine and biology.