FitzHughNagumo1961OdeSystem.cpp

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*/
#include "FitzHughNagumo1961OdeSystem.hpp"
#include "OdeSystemInformation.hpp"
#include <cmath>
 
//
// Model-scope constant parameters
//
const double FitzHughNagumo1961OdeSystem::mAlpha = -0.08;
const double FitzHughNagumo1961OdeSystem::mGamma = 3.00;
const double FitzHughNagumo1961OdeSystem::mEpsilon = 0.005;
 
 
FitzHughNagumo1961OdeSystem::FitzHughNagumo1961OdeSystem(
        boost::shared_ptr<AbstractIvpOdeSolver> pOdeSolver,
        boost::shared_ptr<AbstractStimulusFunction> pIntracellularStimulus)
    : AbstractCardiacCell(pOdeSolver, 2, 0, pIntracellularStimulus)
{
    mpSystemInfo = OdeSystemInformation<FitzHughNagumo1961OdeSystem>::Instance();
 
    Init();
}
 
FitzHughNagumo1961OdeSystem::~FitzHughNagumo1961OdeSystem(void)
{
}
 
void FitzHughNagumo1961OdeSystem::EvaluateYDerivatives(double time, const std::vector<double> &rY, std::vector<double>& rDY)
{
    double membrane_V = rY[0]; // v
    double recovery_variable = rY[1]; // w
 
    double i_stim = GetIntracellularAreaStimulus(time);
 
    // dV/dt
    double membrane_V_prime = 0;
    // do not update voltage if the mSetVoltageDerivativeToZero flag has been set
    if (!mSetVoltageDerivativeToZero)
    {
        membrane_V_prime = membrane_V*(membrane_V-mAlpha)*(1-membrane_V)-recovery_variable+i_stim;
    }
 
    // dw/dt
    double recovery_variable_prime = mEpsilon*(membrane_V-mGamma*recovery_variable);
 
    rDY[0] = membrane_V_prime;
    rDY[1] = recovery_variable_prime;
}
 
double FitzHughNagumo1961OdeSystem::GetIIonic(const std::vector<double>* pStateVariables)
{
    if (!pStateVariables) pStateVariables = &mStateVariables;
    double membrane_V = (*pStateVariables)[mVoltageIndex];
    double recovery_variable = (*pStateVariables)[1];
    double fake_ionic_current = membrane_V*(membrane_V-mAlpha)*(1-membrane_V)-recovery_variable;
    return fake_ionic_current;
}
 
template<>
void OdeSystemInformation<FitzHughNagumo1961OdeSystem>::Initialise(void)
{
    /*
     * State variables
     */
    this->mVariableNames.push_back("V");
    this->mVariableUnits.push_back("mV");
    this->mInitialConditions.push_back(0.0);
 
    this->mVariableNames.push_back("w");
    this->mVariableUnits.push_back("");
    this->mInitialConditions.push_back(0.0);
 
    this->mInitialised = true;
}