Uniform Null Controllability for a Degenerating Reaction-Diffusion   System Approximating a Simplified Cardiac Model
  This paper is devoted to the analysis of the uniform null controllability for a family of nonlinear reaction-diffusion systems approximating a parabolic-elliptic system which models the electrical activity of the heart. The uniform, with respect to the degenerating parameter, null controllability of the approximating system by means of a single control is shown. The proof is based on the combination of Carleman estimates and weighted energy inequalities. 
Mostafa Bendahmane and Felipe Wallison Chaves-Silva
math.OC cs.SY