Model of the human Purkinje cell by Sampson et al.

This implementation is based on the original fortran code published by the authors as supplement to [1].

It was verified against the original code by comparing the calculated derivatives (which matched to within machine precision).

[1] Sampson, Iyer, Marks, Kass (2010) A computational model of Purkinje fibre single cell electrophysiology: implications for the long QT syndrome. Journal of Physiology. doi: 10.1113/jphysiol.2010.187328