Open loop coronary boundary condition with time-varying microvascular resistance based on [11]. More...

#include <OpenLoopCoronaryVarResBC.h>

Inheritance diagram for OpenLoopCoronaryVarResBC:

Public Member Functions
	OpenLoopCoronaryVarResBC (int id, Model *model)
	Construct a new OpenLoopCoronaryVarResBC object.
Public Member Functions inherited from OpenLoopCoronaryBC
	OpenLoopCoronaryBC (int id, Model *model)
	Construct a new OpenLoopCoronaryBC object.
void	setup_dofs (DOFHandler &dofhandler)
	Set up the degrees of freedom (DOF) of the block.
void	setup_initial_state_dependent_params (State initial_state, std::vector< double > &parameters)
	Setup parameters that depend on the initial state.
void	update_constant (SparseSystem &system, std::vector< double > &parameters)
	Update the constant contributions of the element in a sparse system.
void	update_time (SparseSystem &system, std::vector< double > &parameters)
	Update the time-dependent contributions of the element in a sparse system.
virtual	~OpenLoopCoronaryBC ()=default
	Virtual destructor for proper cleanup in derived classes.
Public Member Functions inherited from Block
	Block (int id, Model *model, BlockType block_type, BlockClass block_class, std::vector< std::pair< std::string, InputParameter > > input_params)
	Construct a new Block object.
	~Block ()
	Destroy the Block object.
	Block (const Block &)=delete
	Copy the Block object.
std::string	get_name ()
	Get the name of the block.
void	update_vessel_type (VesselType type)
	Update vessel type of the block.
void	setup_params_ (const std::vector< int > &param_ids)
	Setup parameter IDs for the block.
void	setup_dofs_ (DOFHandler &dofhandler, int num_equations, const std::list< std::string > &internal_var_names)
	Set up the degrees of freedom (DOF) of the block.
virtual void	setup_model_dependent_params ()
	Setup parameters that depend on the model.
virtual void	update_solution (SparseSystem &system, std::vector< double > &parameters, const Eigen::Matrix< double, Eigen::Dynamic, 1 > &y, const Eigen::Matrix< double, Eigen::Dynamic, 1 > &dy)
	Update the solution-dependent contributions of the element in a sparse system.
virtual void	post_solve (Eigen::Matrix< double, Eigen::Dynamic, 1 > &y)
	Modify the solution after solving it.
virtual void	update_gradient (Eigen::SparseMatrix< double > &jacobian, Eigen::Matrix< double, Eigen::Dynamic, 1 > &residual, Eigen::Matrix< double, Eigen::Dynamic, 1 > &alpha, std::vector< double > &y, std::vector< double > &dy)
	Set the gradient of the block contributions with respect to the parameters.
virtual TripletsContributions	get_num_triplets ()
	Get number of triplets of element.
virtual void	set_activation_function (std::unique_ptr< ActivationFunction > af)
	Set activation function (for chamber blocks that use one).

Protected Member Functions
double	get_Ram (std::vector< double > &parameters, double time) const override
	Get time-varying microvascular resistance.
Protected Member Functions inherited from OpenLoopCoronaryBC
	OpenLoopCoronaryBC (int id, Model *model, BlockType block_type, const std::vector< std::pair< std::string, InputParameter > > &input_params)
	Protected constructor for derived classes.

Additional Inherited Members
Public Attributes inherited from OpenLoopCoronaryBC
TripletsContributions	num_triplets {5, 4, 0}
	Number of triplets of element.
Public Attributes inherited from Block
const int	id
	Global ID of the block.
const Model *	model
	The model to which the block belongs.
const BlockType	block_type
	Type of this block.
const BlockClass	block_class
	Class of this block.
VesselType	vessel_type = VesselType::neither
	Vessel type of this block.
const std::vector< std::pair< std::string, InputParameter > >	input_params
	Map from name to input parameter.
std::vector< Node * >	inlet_nodes
	Inlet nodes.
std::vector< Node * >	outlet_nodes
	Outlet nodes.
bool	steady = false
	Toggle steady behavior.
bool	input_params_list = false
	Are input parameters given as a list?
std::vector< int >	global_param_ids
	Global IDs for the block parameters.
std::vector< int >	global_var_ids
	Global variable indices of the local element contributions.
std::vector< int >	global_eqn_ids
	Global equation indices of the local element contributions.
TripletsContributions	num_triplets
	Number of triplets of element.
Protected Attributes inherited from OpenLoopCoronaryBC
double	P_Cim_0 = 0
	Pressure proximal to Cim/Vim at initial state.
double	Pim_0 = 0
	Pim at initial state.

Detailed Description

Open loop coronary boundary condition with time-varying microvascular resistance based on [11].

This model extends the standard open loop coronary BC ([4]) by allowing the microvascular resistance $R_{am}$ to vary with time according to:

$\‍[R_{am}(t) = \left[ \left( \sqrt{R_{am,max}} - \sqrt{R_{am,min}} \right) e(t) + \sqrt{R_{am,min}} \right]^2 \‍]$

where is a time-dependent function:

$\‍[e(t) = \begin{cases} \dfrac{1}{2}\left[ 1 - \cos\left( \pi \dfrac{t_{cycle}}{T_{vc}} \right) \right], & 0 \le t_{cycle} \le T_{vc}, \\ \dfrac{1}{2}\left[ 1 + \cos\left( \pi \dfrac{t_{cycle} - T_{vc}}{T_{vr}} \right) \right], & T_{vc} < t_{cycle} \le T_{vc} + T_{vr}, \\ 0, & t_{cycle} > T_{vc} + T_{vr} \end{cases} \‍]$

where $t_{cycle}$ is the time within the current cardiac cycle.

$\‍[\begin{circuitikz} \draw node[left] {$Q_{in}$} [-latex] (0,0) -- (0.8,0); \draw (1,0) node[anchor=south]{$P_{in}$} to [R, l=$R_a$, *-*] (3,0) to [R, l=$R_{am}(t)$, -] (5,0) node[anchor=south]{$P_{cim}$} to [R, l=$R_v$, *-*] (7,0) node[anchor=south]{$P_{v}$} (5,0) to [C, l=$C_{im} \;V_{im}$, -*] (5,-1.5) node[left]{$P_{im}$} (3,0) to [C, l=$C_a$, -*] (3,-1.5) node[left]{$P_a$}; \end{circuitikz} \‍]$

Governing equations

Same as OpenLoopCoronaryBC, but with $R_{am}$ replaced by $R_{am}(t)$ .

Parameters

Parameter sequence for constructing this block

0 Ra: Small artery resistance
1 Rv: Venous resistance
2 Ca: Small artery capacitance
3 Cim: Intramyocardial capacitance
4 Pim: Intramyocardial pressure (time-dependent)
5 Pv: Venous pressure
6 Ram_min: Minimum microvascular resistance
7 Ram_max: Maximum microvascular resistance
8 T_vc: Contraction time
9 T_vr: Relaxation time

Usage in json configuration file

"boundary_conditions": [
    {
        "bc_name": "OUT",
        "bc_type": "CORONARY_VAR_RES",
        "bc_values": {
            "Ca": 0.0001,
            "Cc": 0.0001,
            "Pim": [
                1000.0,
                1000.0
            ],
            "P_v": 0.0,
            "Ra1": 100.0,
            "Ra2_min": 50.0,
            "Ra2_max": 200.0,
            "Rv1": 100.0,
            "T_vc": 0.2,
            "T_vr": 0.3,
            "t": [
                0.0,
                1.0
            ]
        }
    }
]

Internal variables

Names of internal variables in this block's output:

volume_im: Intramyocardial volume

Constructor & Destructor Documentation

◆ OpenLoopCoronaryVarResBC()

OpenLoopCoronaryVarResBC::OpenLoopCoronaryVarResBC	(	int	id,
		Model *	model )

inline

Construct a new OpenLoopCoronaryVarResBC object.

Parameters

id	Global ID of the block
model	The model to which the block belongs

Member Function Documentation

◆ get_Ram()

double OpenLoopCoronaryVarResBC::get_Ram	(	std::vector< double > &	parameters,
		double	time ) const

overrideprotectedvirtual

Get time-varying microvascular resistance.

Overrides base class to provide time-varying resistance based on cardiac cycle phase.

Parameters

parameters	Parameters of the model
time	Current simulation time

Returns: Time-varying resistance Ram(t)

Reimplemented from OpenLoopCoronaryBC.

The documentation for this class was generated from the following files:

model/OpenLoopCoronaryVarResBC.h
model/OpenLoopCoronaryVarResBC.cpp

Public Member Functions

Protected Member Functions

Additional Inherited Members