class IT0_TC {
  static double Ca_0, Cels, Qm, Qh;
  double m_inf, tau_m, h_inf, tau_h, Phi_h, Phi_m, ratio, eca, eca0; 

public:
  double iT0, m0, h0, Shift_m, Shift_h;
  double G_Ca0;
  IT0_TC(double v);
  void init(double v);
  void calc(double m, double h, double &fm, double &fh,  
            double v, double cai, double x);
};