Body Male - Realistic, by Dan Ulrich.
Official Blender Human Base Meshes bundle v1.4.1.
Publisher: Blender Studio and community contributors.
License: CC0 1.0 Universal (public domain dedication).

Source page: https://www.blender.org/download/demo-files/#assets
Source archive: https://download.blender.org/demo/asset-bundles/human-base-meshes/human-base-meshes-bundle-v1.4.1.zip

The official listing marks this bundle CC0. Its embedded README says:
"All provided assets are public domain under the CC0 license."
The collection "Body Male - Realistic" credits Dan Ulrich and describes
this model as "Realistic scan data model with multiresolution details".
An unrelated legacy text block named License mentions the Rain Rig;
that rig is not used here. The bundle README and official listing agree
on the CC0 license of this body asset.

Adaptation: export body at multiresolution level 2, include eyeball meshes,
triangulate, rotate to supine display coordinates, uniformly scale to
millimetres, translate to the existing examination table. Preserve the
artist's natural A-pose. The file contains geometry only; no scripts.
170454 vertices, 340896 triangles. Rebuild with tools/prepare-blender-human.py.
Model/archive hashes and further metadata: source.json.

The displayed person is not the patient in the ultrasound footage.
This exterior model does not provide medical registration of the footage.
The previous MakeHuman mesh has been replaced; prepare-human.py is retained
only as the legacy v0.3 conversion recipe.