AhaStrainCalculator

class ansys.health.heart.post.strain_calculator.AhaStrainCalculator(model: ansys.health.heart.models.HeartModel, d3plot_file)

Compute longitudinal, radial, and circumferential strain for the left ventricle.

Overview

Methods

compute_longitudinal_radial_strain	Compute longitudinal and radial strain.
compute_aha_strain	Compute AHA 17 segment strain values from the deformation gradient.
compute_aha_strain_at	Export AHA strain and/or save a VTK file for a given frame.

Attributes

model
aha_labels
d3plot

Static methods

bullseye_17_segments

Bullseye representation of the 17 segments of the left ventricle.

Import detail

from ansys.health.heart.post.strain_calculator import AhaStrainCalculator

Attribute detail

AhaStrainCalculator.model

AhaStrainCalculator.aha_labels

AhaStrainCalculator.d3plot

Method detail

AhaStrainCalculator.compute_longitudinal_radial_strain(time_array: numpy.ndarray | list = None, vtk_dir: pathlib.Path | str = None) → tuple[numpy.ndarray, numpy.ndarray]

Compute longitudinal and radial strain.

Longitudinal and radial strain (V_i and H_i) values are saved with the following format:

P1—H1—P2—H2—P3—-H3–P4—H4—P5—H5—P6—H6—P1 | | | | | | | | | | | | | | V1 S4 V2 S5 V3 S6 V4 S1 V5 S2 V6 S3 V1 | | | | | | | | | | | | | | P7—H7—P8—H8—P9—-H9–P10–H10–P11–H11–P12–H12–P7 | | | | | | | | | | | | | | V7 S10 V8 S11 V9 S12 V10 S7 V11 S8 V12 S9 V7 | | | | | | | | | | | | | | P13–H13–P14–H14–P15–H15–P16–H16–P17–H17–P18–H18–P13

P19—H19—P20—H20—P21—H21—P22—H22—P19 | | | | | | | | | | V13 S15 V14 S16 V15 S13 V16 S14 V13 | | | | | | | | | | P23—H23—P24—H24—P25—H25—P26—H26—P23

Parameters:

time_arraynp.ndarray | list, optional

Array of time points to compute strain at. If None, all time points are used.

vtk_dirpathlib.Path | str, optional

Directory to save VTK files. If None, no VTK files are saved.

Returns:

tuple[np.ndarray, np.ndarray]

Longitudinal and radial strain arrays of 17 segments.

AhaStrainCalculator.compute_aha_strain(out_dir: str = None, write_vtk: bool = False, t_to_keep: float = 100000000000.0) → numpy.ndarray

Compute AHA 17 segment strain values from the deformation gradient.

Parameters:

out_dirstr, default: None

Output folder.

write_vtkbool, default: False

Whether to write to VTK files.

t_to_keepfloat, default: 10e10

Time to stop.

Returns:

np.ndarray

Array of N_time * (1+17*3). Columns represent time and longitudinal, radial, and circumferential strain averaged of each segment.

AhaStrainCalculator.compute_aha_strain_at(frame: int = 0, out_dir: pathlib.Path = None) → numpy.ndarray

Export AHA strain and/or save a VTK file for a given frame.

Parameters:

frame: int, default: 0

Frame number to compute strain.

out_dir: pathlib.Path, default: None

Directory to save VTK file to. No VTK file is saved by default.

Returns:

np.ndarry

AHA LRC strain matrix (17 * 3).

static AhaStrainCalculator.bullseye_17_segments(ax, data) → None

Bullseye representation of the 17 segments of the left ventricle.

Parameters:

axaxes

datalist of int and float

Intensity values for each of the 17 segments.

Notes

This function creates the 17-segment model for the left ventricle according to the American Heart Association (AHA) [1].

This method is modified from the Matplotlibs bullseye example. Copyright© 2012- Matplotlib Development Team; All Rights Reserved. Modifications consisted of removing colors and including the values for each segment.

References

[1]

M. D. Cerqueira, N. J. Weissman, V. Dilsizian, A. K. Jacobs, S. Kaul, W. K. Laskey, D. J. Pennell, J. A. Rumberger, T. Ryan, and M. S. Verani, “Standardized myocardial segmentation and nomenclature for tomographic imaging of the heart”, Circulation, vol. 105, no. 4, pp. 539-542, 2002.