NhsContractionModel Class Reference

#include <NhsContractionModel.hpp>

Inherits AbstractOdeBasedContractionModel.

Inherited by NhsModelWithBackwardSolver.

Collaboration diagram for NhsContractionModel:

Public Member Functions
	NhsContractionModel ()
void	SetStretchAndStretchRate (double lambda, double dlambdaDt)
void	SetInputParameters (ContractionModelInputParameters &rInputParameters)
void	SetIntracellularCalciumConcentration (double calciumConcentration)
double	GetCalciumTroponinValue ()
void	EvaluateYDerivatives (double time, const std::vector< double > &rY, std::vector< double > &rDY)
double	GetActiveTension ()
double	GetNextActiveTension ()
bool	IsStretchDependent ()
bool	IsStretchRateDependent ()
Protected Member Functions
void	CalculateCalciumTrop50 ()
double	CalculateT0 (double z)
Protected Attributes
double	mLambda
double	mDLambdaDt
double	mCalciumI
double	mCalciumTrop50
double	mK1
double	mK2
Static Protected Attributes
static const double	mKon = 100
static const double	mKrefoff = 0.2
static const double	mGamma = 2
static const double	mCalciumTroponinMax = 0.07
static const double	mAlphaR1 = 0.002
static const double	mAlphaR2 = 0.00175
static const double	mKZ = 0.15
static const unsigned	mNr = 3u
static const double	mBeta1 = -4
static const double	mAlpha0 = 0.008
static const unsigned	mN = 3u
static const double	mZp = 0.85
static const double	mCalcium50ref = 0.00105
static const double	mTref = 56.2
static const double	mBeta0 = 4.9
static const double	mA = 0.35
static const double	mA1 = -29
static const double	mA2 = 138
static const double	mA3 = 129
static const double	mAlpha1 = 0.03
static const double	mAlpha2 = 0.130
static const double	mAlpha3 = 0.625
Friends
class	TestContractionModels

Detailed Description

NHS (Niederer, Hunter, Smith) model of active tension in cardiac cells.

A system of ODEs which determines the active potential, given the intracellular calcium concentration, the stretch (lambda) of the cell, and the stretch rate (dlambda_dt) of the cell.

The state variables are, in order: Calcium_troponin, z, Q1, Q2, Q3

Reference: S.A. Niederer, N.P. Smith, P.J. Hunter, "New developments in a strongly coupled cardiac electro-mechanical model" Europace 7, S118-S127

The active tension is returned in KPa.

Definition at line 48 of file NhsContractionModel.hpp.

Constructor & Destructor Documentation

NhsContractionModel::NhsContractionModel ( )

Constructor. Initialises all state variables to zero, lambda to 1, dlambda_dt to 0 and intracellular calcium concentration to 0

Definition at line 92 of file NhsContractionModel.cpp.

References CalculateCalciumTrop50(), AbstractOdeSystem::GetInitialConditions(), mAlphaR2, mCalciumI, mDLambdaDt, mK1, mK2, mKZ, mLambda, mNr, AbstractOdeSystem::mpSystemInfo, mZp, and AbstractOdeSystem::SetStateVariables().

Member Function Documentation

void NhsContractionModel::CalculateCalciumTrop50 ( ) [protected]

Compute the calcium_trop50 concentration. This is a function of constants and lambda, so only needs to be called in the constructor or when lambda is set

Definition at line 67 of file NhsContractionModel.cpp.

References mBeta1, mCalcium50ref, mCalciumTrop50, mCalciumTroponinMax, mGamma, mKon, mKrefoff, and mLambda.

Referenced by NhsContractionModel(), and SetStretchAndStretchRate().

double NhsContractionModel::CalculateT0 ( double z ) [protected]

Calculate T0. This is a function of constants, lambda and z

Parameters:

z

Definition at line 76 of file NhsContractionModel.cpp.

References mAlpha0, mAlphaR1, mBeta0, mCalciumTrop50, mCalciumTroponinMax, mK1, mK2, mLambda, mN, and mTref.

Referenced by NhsModelWithBackwardSolver::CalculateCaTropAndZDerivatives(), EvaluateYDerivatives(), GetActiveTension(), and NhsModelWithBackwardSolver::GetNextActiveTension().

void NhsContractionModel::EvaluateYDerivatives	(	double	time,
		const std::vector< double > &	rY,
		std::vector< double > &	rDY
	)			`[virtual]`

Evaluate the derivatives of the state variables

Parameters:

	time	the current time, in milliseconds
	rY	current values of the state variables
	rDY	to be filled in with derivatives

Implements AbstractOdeSystem.

Definition at line 141 of file NhsContractionModel.cpp.

References CalculateT0(), mA, mA1, mA2, mA3, mAlpha0, mAlpha1, mAlpha2, mAlpha3, mAlphaR1, mAlphaR2, mCalciumI, mCalciumTrop50, mCalciumTroponinMax, mDLambdaDt, mGamma, mKon, mKrefoff, mKZ, mN, mNr, and mTref.

double NhsContractionModel::GetActiveTension ( ) [virtual]

Get the active tension, which is a function of the constants and current state variables. KILOPASCALS

Implements AbstractContractionModel.

Definition at line 199 of file NhsContractionModel.cpp.

References CalculateT0(), mA, and AbstractOdeSystem::mStateVariables.

double NhsContractionModel::GetCalciumTroponinValue ( )

Get the current Calcium Troponin (one of the state variables) value. This may be needed if the cell model has Calcium troponin and might need overwriting

Definition at line 136 of file NhsContractionModel.cpp.

References AbstractOdeSystem::mStateVariables.

double NhsContractionModel::GetNextActiveTension ( ) [inline, virtual]

GetNextActiveTension() normally returns the active tension corresponding to the state variables that have been computed in RunDoNotUpdate. However, this only applies to when an implicit cardiac mechanics solver is used, in which case the NhsModelWithBackwardSolver should be used.

Implements AbstractContractionModel.

Reimplemented in NhsModelWithBackwardSolver.

Definition at line 203 of file NhsContractionModel.hpp.

bool NhsContractionModel::IsStretchDependent ( ) [inline, virtual]

This model is stretch-dependent

Implements AbstractContractionModel.

Definition at line 211 of file NhsContractionModel.hpp.

bool NhsContractionModel::IsStretchRateDependent ( ) [inline, virtual]

This model is stretch-rate-dependent

Implements AbstractContractionModel.

Definition at line 219 of file NhsContractionModel.hpp.

void NhsContractionModel::SetInputParameters ( ContractionModelInputParameters & rInputParameters ) [virtual]