UserTutorials/Monodomain3dRabbitHeart

This tutorial is automatically generated from the file trunk/heart/test/tutorials/TestMonodomain3dRabbitHeartTutorial.hpp at revision r21674. Note that the code is given in full at the bottom of the page.

3D monodomain rabbit heart example

This tutorial runs a simulation on a whole rabbit heart mesh. Note that this mesh is far too coarse for converged simulations, but provides a useful example.

First include the headers, MonodomainProblem this time. 

#include <cxxtest/TestSuite.h>
#include "MonodomainProblem.hpp"
#include "LuoRudy1991BackwardEuler.hpp"
#include "PetscSetupAndFinalize.hpp"
#include "GenericMeshReader.hpp"
#include "DistributedTetrahedralMesh.hpp"

Here we define a cell factory that gives stimuli to all cells below height z = 0.042... this corresponds to the apex of the heart. 

class RabbitHeartCellFactory : public AbstractCardiacCellFactory<3> // <3> here
{
private:
    boost::shared_ptr<SimpleStimulus> mpStimulus;

public:
    RabbitHeartCellFactory()
        : AbstractCardiacCellFactory<3>(), // <3> here as well!
          mpStimulus(new SimpleStimulus(-80000.0, 2))
    {
    }

    AbstractCardiacCell* CreateCardiacCellForTissueNode(Node<3>* pNode)
    {
        double z = pNode->rGetLocation()[2];

        if (z <= 0.05)
        {
            return new CellLuoRudy1991FromCellMLBackwardEuler(mpSolver, mpStimulus);
        }
        else
        {
            return new CellLuoRudy1991FromCellMLBackwardEuler(mpSolver, mpZeroStimulus);
        }
    }
};

Now define the test 

class TestMonodomain3dRabbitHeartTutorial : public CxxTest::TestSuite
{
public:
    void TestMonodomain3dRabbitHeart() throw(Exception)
    {

        HeartConfig::Instance()->SetMeshFileName("apps/texttest/weekly/Propagation3d/OxfordRabbitHeart_482um",
                                                 cp::media_type::Axisymmetric);

Specify the conductivity vector to use in the simulation. Since this is going to be a monodomain simulation, we only specify intra-cellular conductivities. Additionally, because this is an Axi-symmetric mesh then we must specify conductivity along the sheet and normal directions to be the same (an exception will be thrown if not).

The 3rd entry would be different for an orthotropic mesh with fibre, sheet and normal directions. For a simulation without fibre directions, there should be one value. 

        HeartConfig::Instance()->SetIntracellularConductivities(Create_c_vector(1.75, 0.19, 0.19));

Set the simulation duration, output directory, filename and VTK visualization.

We have set the simulation duration to be very short here so this tutorial runs quickly, increase it to see decent propagation of the wavefront. 

        HeartConfig::Instance()->SetSimulationDuration(2); //ms
        HeartConfig::Instance()->SetOutputDirectory("Monodomain3dRabbitHeart");
        HeartConfig::Instance()->SetOutputFilenamePrefix("results");
        HeartConfig::Instance()->SetVisualizeWithVtk(true);

The ODE and PDE timesteps should be refined when using this code for real scientific simulations. The values here are sufficient to ensure stability in this case, but not sufficient for converged numerical behaviour. 

        HeartConfig::Instance()->SetOdePdeAndPrintingTimeSteps(0.02, 0.1, 0.2);

Here we create an instance of our cell factory, which will tell the MonodomainProblem class which action potential models to use at which nodes. The rest of the problem is set up identically to Monodomain3dExample. 

        RabbitHeartCellFactory cell_factory;
        MonodomainProblem<3> monodomain_problem( &cell_factory );
        monodomain_problem.SetWriteInfo();
        monodomain_problem.Initialise();
        monodomain_problem.Solve();

We can access nodes in the mesh using a NodeIterator. Here, we check that each node has not been assigned to bath, and throw an error if it has. This is not a particularly useful test, but it does demonstrate the principle. 

        AbstractTetrahedralMesh<3,3>* p_mesh = &(monodomain_problem.rGetMesh());

        for (AbstractTetrahedralMesh<3,3>::NodeIterator iter = p_mesh->GetNodeIteratorBegin();
                         iter != p_mesh->GetNodeIteratorEnd(); ++iter)
        {
            TS_ASSERT_EQUALS(HeartRegionCode::IsRegionBath( iter->GetRegion() ), false);
        }
    }
};

Note if you were doing a 'real' scientific simulation you would want to use a higher resolution mesh. A version of this can be found on the  Chaste download website

Navigate to the "Data" tab, and download either

These will probably require HPC resources, and finer ODE and PDE time steps than we used here.

To visualize these results, see ChasteGuides/VisualisationGuides/ParaviewForCardiac. The colour axes in Paraview may need to be rescaled in order to see the voltage changes.

Code

The full code is given below

File name TestMonodomain3dRabbitHeartTutorial.hpp

#include <cxxtest/TestSuite.h>
#include "MonodomainProblem.hpp"
#include "LuoRudy1991BackwardEuler.hpp"
#include "PetscSetupAndFinalize.hpp"
#include "GenericMeshReader.hpp"
#include "DistributedTetrahedralMesh.hpp"

class RabbitHeartCellFactory : public AbstractCardiacCellFactory<3> // <3> here
{
private:
    boost::shared_ptr<SimpleStimulus> mpStimulus;

public:
    RabbitHeartCellFactory()
        : AbstractCardiacCellFactory<3>(), // <3> here as well!
          mpStimulus(new SimpleStimulus(-80000.0, 2))
    {
    }

    AbstractCardiacCell* CreateCardiacCellForTissueNode(Node<3>* pNode)
    {
        double z = pNode->rGetLocation()[2];

        if (z <= 0.05)
        {
            return new CellLuoRudy1991FromCellMLBackwardEuler(mpSolver, mpStimulus);
        }
        else
        {
            return new CellLuoRudy1991FromCellMLBackwardEuler(mpSolver, mpZeroStimulus);
        }
    }
};

class TestMonodomain3dRabbitHeartTutorial : public CxxTest::TestSuite
{
public:
    void TestMonodomain3dRabbitHeart() throw(Exception)
    {
        HeartConfig::Instance()->SetMeshFileName("apps/texttest/weekly/Propagation3d/OxfordRabbitHeart_482um",
                                                 cp::media_type::Axisymmetric);

        HeartConfig::Instance()->SetIntracellularConductivities(Create_c_vector(1.75, 0.19, 0.19));

        HeartConfig::Instance()->SetSimulationDuration(2); //ms
        HeartConfig::Instance()->SetOutputDirectory("Monodomain3dRabbitHeart");
        HeartConfig::Instance()->SetOutputFilenamePrefix("results");
        HeartConfig::Instance()->SetVisualizeWithVtk(true);

        HeartConfig::Instance()->SetOdePdeAndPrintingTimeSteps(0.02, 0.1, 0.2);

        RabbitHeartCellFactory cell_factory;
        MonodomainProblem<3> monodomain_problem( &cell_factory );
        monodomain_problem.SetWriteInfo();
        monodomain_problem.Initialise();
        monodomain_problem.Solve();

        AbstractTetrahedralMesh<3,3>* p_mesh = &(monodomain_problem.rGetMesh());

        for (AbstractTetrahedralMesh<3,3>::NodeIterator iter = p_mesh->GetNodeIteratorBegin();
                         iter != p_mesh->GetNodeIteratorEnd(); ++iter)
        {
            TS_ASSERT_EQUALS(HeartRegionCode::IsRegionBath( iter->GetRegion() ), false);
        }
    }
};