Abstract:

Electrical activity in biological media can be described in a mathematical way, which is applicable to computer-based simulation. Biophysically mathematical descriptions provide important insights into the electrical and electrophysiological properties of cells, tissues, and organs. Examples of these descriptions are Maxwell's and Poisson's equations for electromagnetic and electric fields. Commonly, numerical techniques are applied to calculate electrical fields, e.g. the finite element method. Finite elements can be classified on the order of the underlying Interpolation. High-order finite elements provide enhanced geometric flexibility and can increase the accuracy of a solution. The aim of this work is the design of a framework for describing and solving high-order finite elements in the SCIRun/BioPSE software system, which allows geometric modeling, simulation, and visualization for solving bioelectric field problems. Currently, only low-order elements are supported. Our design for high-order elements concerns interpolation of geometry and physical fields. The design is illustrated by an implementation of one-dimensional elements with cubic interpolation of geometry and field variables.

Abstract:

Computational modeling and simulation can provide important insights into the electrical and electrophysiological properties of cells, tissues, and organs. Commonly, the modeling is based on Maxwell's and Poisson's equations for electromagnetic and electric fields, respectively, and numerical techniques are applied for field calculation such as the finite element and finite differences methods. Focus of this work are finite element methods, which are based on an element-wise discretization of the spatial domain. These methods can be classified on the element's geometry, e.g. triangles, tetrahedrons and hexahedrons, and the underlying interpolation functions, e.g. polynomials of various order. Aim of this work is to describe finite element-based approaches and their application to extend the problem-solving environment SCIRun/BioPSE. Finite elements of various types were integrated and methods for interpolation and integration were implemented. General methods for creation of finite element system matrices and boundary conditions were incorporated. The extension provides flexible means for geometric modeling, physical simulation, and visualization with particular application in solving bioelectric field problems.