Solution of exterior 3D time dependent diffusion problems by boundary elements

Extracellular potassium can markedly affect the excitability of cells. Furthermore, there are morphological structures which place large regions of neighbouring membranes in extremely close apposition thereby creating highly restrictive diffusional volumes. Thus, potassium ions may accumulate in the extracellular spaces and become an important factor in cell coupling. Solving exterior time-dependent diffusion problems using boundary elements has proved to be problematic for several reasons. Recently, a technique was introduced to transform exterior problems to interior ones. This technique is expanded to three dimensions and an example given to illustrate its validity