Anatomy sources & simulation methods

The Digital Twin and Physiology Lab show reference anatomy with illustrative motion. These models have not been validated for diagnosis, treatment planning, pregnancy monitoring or biomechanical prediction.

Male reference

Human Atlas supplies 2,234 individually selectable BodyParts3D 4.0 meshes. BodyParts3D, © The Database Center for Life Science, is licensed under CC BY 4.0. Source units and axes were converted and geometry simplified for browser use.

The male view also includes 20 bronchopulmonary surface segments from OpenMedical's HRA v1.2 male reference. Credit: Browne, Schlehlein, Herr, Quardokus and Börner (2022), HuBMAP CCF 3D Reference Object Library v1.2, CC BY 4.0. Their world transforms were baked and the assembly translated upward by 0.81 m for visual registration.

Female anatomical reconstruction

The female view uses the Human Atlas female reconstruction, with full-body muscles and skeleton adapted from the same BodyParts3D source used by the male view. It includes the chest, abdomen, back, shoulders, arms, hands, legs and feet. The framework is reshaped toward estimated female proportions; it is not a female donor scan.

Female pelvic bones, reproductive organs, breast tissues and full-body skin come from Kristen Browne and Heidi Schlehlein, Human Reference Atlas / HuBMAP, 3D Reference Organ Set for Female v1.5 (2023), CC BY 4.0. The upstream reconstruction retains 2,181 BodyParts3D meshes and adds 64 adapted HRA meshes. OpenMedical also registers the original HRA female skin to the reconstructed body. Each selectable structure retains its source identifier and adaptation notes.

OpenMedical adds source-derived female lungs and matching airways under one shared registration to the thorax. These replace the overlapping BodyParts3D airway meshes as one assembly. It also fits the walking pivots to the reconstructed bones. The adaptation record documents geometry changes, source hashes and checks.

This is an educational reconstruction. Proportions, organ placement and tissue attachments remain estimates. Some pelvic-floor structures are absent from the source reconstruction. Geometry integrity and connected animation checks do not establish anatomical or clinical accuracy.

Included geometry

These are actual selectable meshes, with no duplicated or subdivided structures added to raise the count. Mesh counts differ with source segmentation and do not measure anatomical completeness. Totals include successful lung supplements; if a supplement cannot load, the viewer reports the available geometry and offers a retry.

Rendering & adaptations

Body surface shows opaque, assembled skin, including the head, torso, arms, hands, legs and feet. Explore anatomy uses transparent skin as context; the opacity control adjusts its visibility. The female skin is registered reference geometry. It retains the original surface topology, with estimated alignment to the internal reconstruction.

Human Atlas application code is MIT licensed. OpenMedical adapts batched geometry and exploded layouts, preserving names and source identifiers. Geometry downloads use immutable source revisions. Per-structure transforms drive rendering and picking together. No patient data is included in asset requests.

Five source nasal cartilages overlap the skin near the nose tip. They are hidden in the assembled overview. Use Include nasal cartilage under Anatomical layers, search for a cartilage, or explode its layer to inspect it. Nasal bones remain visible. This display choice preserves source geometry.

Breathing

The illustrative cycle uses a smooth inspiration occupying 38% of a cycle, followed by a longer expiration. Lungs expand laterally and descend at their bases while the diaphragm moves downward. The volume setting controls deformation; mesh volume is not calibrated to that setting. See NHLBI: what breathing does for the body. Timings and deformation coefficients are teaching assumptions.

Walking & heartbeat

Each model uses its own estimated hip, knee, ankle, shoulder and elbow centres measured from its bone geometry. Wrist, thumb and finger bones follow the forearm; feet follow the ankle. Linked rigid transforms keep the skeleton assembled throughout the cycle. Soft tissues spanning joints remain available in Explore anatomy and Muscles.

The illustrative gait uses a 60% stance fraction and approximate patellar tracking. It does not solve contact forces, balance, muscle forces or inverse dynamics. For measured biomechanics, see OpenSim's experimental-data workflow. Heartbeat uses source heart membership and a shared contraction pivot, excluding laryngeal and cerebral ventricular structures; it does not calculate blood flow or pressure.

Omitted source structures

The detached HRA placenta, amnion and umbilical reference assembly is excluded from the adult viewer, layers and search. The female reconstruction excludes male-specific reproductive anatomy and some shared pelvic-floor structures. Female reproductive organs remain available.

Computational biology labs

Sequence algorithms, molecular structures, protein folding and dynamics retain their documented methods and assumptions. Reduced-unit simulations are not experimentally calibrated predictions. Only the selected laboratory instrument runs at a time.