Preprocessor

This topic provides an overview of the preprocessor module. Use this module to preprocess a case from the following two public datasets:

• A Publicly Available Virtual Cohort of Four-chamber Heart Meshes for Cardiac Electro-mechanics Simulations

• Virtual cohort of adult healthy four-chamber heart meshes from CT images

The preprocessor module provides methods to extract the necessary information and VTP object from these two databases. You can then process this data further and use it with the HeartModel.load_input method. The module also includes methods to conveniently download data from these two public sources.

from ansys.health.heart.utils.download import download_case_from_zenodo, unpack_case
tar_file = download_case_from_zenodo("Rodero2021", 1, "my-download-dir")
file_path = unpack_case(tar_file)

The file_path variable contains the path to the downloaded and unpacked CASE or VTK file.

Alternatively, you can provide your own set of input files. Specify a path to the VTP/VTK file that describes the input geometry and a JSON file that describes the parts.

The part definitions JSON file has the following format:

part_definitions = {
    "Left ventricle": {
        "id": 1,
        "enclosed_by_boundaries": {
            "left-ventricle-endocardium": 1,
            "left-ventricle-epicardium": 2,
            "interface_left-ventricle-myocardium_mitral-valve": 3,
        },
    }
}

The id represents the volumetric part ID, and enclosed_by_boundaries contains the IDs of the boundaries that enclose the volumetric part. Add a cell data array called surface-id so that the preprocessor can identify the IDs of the enclosing boundaries. The HeartModel reads the input model and part definitions JSON file.

# Initialize left-ventricular heart model.
model = models.LeftVentricle(working_directory="my-working-dir")
# Load input model and part definitions:
model.load_input(heart, part_definitions, "surface-id")

Use the HeartModel.mesh_volume method to generate the volumetric meshes from the input model.

# Remesh the model using wrapping
model.mesh_volume(use_wrapper=True, global_mesh_size=1.0)

For comprehensive examples, see Preprocessor examples.