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#

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.

model

aha_labels

d3plot

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:
frameint, default: 0

Frame number to compute strain.

out_dirpathlib.Path, default: None

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

Returns:
np.ndarray

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:
axmatplotlib.axes.Axes

Matplotlib polar axes used for plotting the bullseye.

datalist[int | float] | np.ndarray

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.