Contributed EIT Data:

Authors: Andrew Tizzard, Middlesex University, Bramley Road, London N14 4YZ.
Date: October 2007. (Created from 2002 to 2006)
Brief Description: A range Finite Element meshes of different densities for the human head including two neonate meshes.

The underlying geometry is described in Tizzard et al. (2005b) and all meshes except SA262 are used in Tizzard & Bayford (2007a)


License: Creative Commons Artistic License (with Attribution)
Attribution Requirement: Tizzard, A. and Bayford, R.H. (2007). Improving the Finite Element Forward Model of the Human Head by Warping using Elastic Deformation. Physiol.Meas. 28:S163-S182.
Format: Data are in Matlab v6 format, compressed with 7-Zip

Each model is shelled comprising regions defining Scalp, Skull, CSF and brain as defined by the materials structure. The important arrays in this structure are names and ref. The vector ref relates elements (tri) to each region by index into the names array. Nodal positions (mm) are defined by the vtx array.

The underlying geometry is described in Tizzard et al. (2005b) and all meshes except SA262 are used in Tizzard and Bayford (2007a)


Methods: Geometry generated using Alias Studio Tools (now Autodesk Alias) and the meshing carried out using EDS I-DEAS (now UGS NX).

The tables below give a summary of the adult and neonate head meshes. They are all shelled comprising regions defining Scalp, Skull, CSF and brain. The underlying geometry is described in Tizzard et al. (2005b) and all meshes except SA262 are used in Tizzard and Bayford (2007a) Some of these meshes and others based on the same underlying geometry have been used by the UCL and Middlesex groups (Bagshaw et al. 2003; Bayford et al. 2005; Bayford et al. 2006b; Bayford et al. 2006a; Horesh et al. 2004; Tizzard et al. 2005a; Tizzard and Bayford 2007b; Yerworth et al. 2004).

Summary of shelled adult head meshes.
Number of
Elements
Number of
Nodes
Stretch
Minimum
Stretch
Maximum
Stretch
Mean
Model
Name
27684 5226 0.0018 0.9641 0.6025 SAH028
31111 5939 0.0257 0.9770 0.6605 SAH031
35073 6556 0.0254 0.9781 0.6310 SAH035
49172 9142 0.0691 0.9815 0.6572 SAH049
77196 14188 0.0570 0.9869 0.6752 SAH077
131672 24688 0.1046 0.9896 0.6794 SAH132
262368 48394 0.0970 0.9878 0.6833 SAH262

Summary of shelled neonate head meshes
Number of
Elements
Number of
Nodes
Stretch
Minimum
Stretch
Maximum
Stretch
Mean
Model
Name
45702 8703 0.024 0.982 0.643 SNH046
142654 26586 0.033 0.988 0.686 SNH143

References

  • Bagshaw, A., Liston, A. D., Bayford, R. H., Tizzard, A., Gibson, A., Tidswell, A. T., Sparkes, M. K., Dehghani, H., Binnie, C. D. and Holder, D. S. (2003) "Electrical impedance tomography of human brain function using reconstruction algorithms based on the finite element method." Neuroimage 20, pp752-64.
  • Bayford, R. H., Tizzard, A. and Liu, X. (2005) "Dynamic modelling of electrical current distribution in the deep structure of the brain." Proceedings of the 3rd IEE International Seminar on Medical Applications of Signal Processing (London, UK: Institute of Electrical Engineers), pp131-4.
  • Bayford, R. H., Tizzard, A. and Liu, X. (2006a) "The Forward Model", 7th conference on Biomedical Applications of Electrical Impedance Tomography (Seoul, South Korea), p21.
  • Bayford, R. H., Tizzard, A., Yousif, N. and Liu, X. (2006b) "Investigating the mechanism of deep brain stimulation using a dynamic complex model of the head incorporated with the complete model of electrode" Clin. Neurophys. 117, ppS219-S220.
  • Horesh, L., Bayford, R. H., Yerworth, R. J., Tizzard, A., Ahadzi, G. E. and Holder, D. S. (2004) "Beyond the linear domain - the way forward in MFEIT reconstruction of the human head." XII International Conference on Electrical Bioimpedance and V Electrical Impedance Tomography (Gdansk, Poland: Gdansk University of Technology), pp683-6.
  • Tizzard, A. and Bayford, R. H. (2007a) "Improving the Finite Element Forward Model of the Human Head by Warping using Elastic Deformation." Physiol. Meas. 28, ppS163-S182.
  • Tizzard, A. and Bayford, R. H. (2007b) "Validation of Finite Element mesh warping for improving the forward model in EIT of brain function." 13th International Conference on Electrical Bioimpedance & 8th Conference on Electrical Impedance Tomography. (Graz, Austria: Springer-Verlag).
  • Tizzard, A., Holder, D. S. and Bayford, R. H. (2005a) "Generating surfaces for registration and warping FE meshes for the forward model in EIT of brain function" EMBEC05: The 3rd European Medical and Biological Engineering Conference (Prague, Cz: IFMBE).
  • Tizzard, A., Horesh, L., Yerworth, R. J., Holder, D. S. and Bayford, R. H. (2005b) "Generating accurate finite element meshes for the forward model of the human head in EIT" Physiol. Meas. 26, ppS251-S261.
  • Yerworth, R. J., Horesh, L., Bayford, R. H., Tizzard, A. and Holder, D. S. (2004) "Robustness of linear and nonlinear reconstruction algorithms for brain EITS" XII International Conference on Electrical Bioimpedance and V Electrical Impedance Tomography (Gdansk, Poland: Gdansk University of Technology).

Data:
Adult head meshes:
SAH028 (27684 elements),
SAH031 (31111 elements),
SAH035 (35073 elements),
SAH049 (49172 elements),
SAH077 (77196 elements),
SAH132 (131672 elements),
SAH262 (262368 elements)
Neonate head meshes:
SNH046 (45702 elements)
SNH143 (142654 elements)
Example images:
 for str = {'SAH028', 'SAH262'}
    load(str{1});
    ee= find_boundary(tri);
    trimesh(ee,vtx(:,1),vtx(:,2),vtx(:,3))
    hh=trimesh(ee,vtx(:,1),vtx(:,2),vtx(:,3));
    set(hh,'EdgeColor', [0,0,0]);
    axis tight
    axis equal
    view(-55,10);
    print('-dpng','-r100',[str{1},'.png']);
end
SAH028-mesh SAH262-mesh
Figure: Left: Outer boundary of SAH028 (27684 element) mesh Right: Outer boundary of SAH262 (262368 elements) mesh Last Modified: $Date: 2017-02-28 13:12:08 -0500 (Tue, 28 Feb 2017) $ by $Author: aadler $