Preparing anatomy and conduction…
Loading anatomy…
RestingDepolarizedRecoveryResting
SARALALL
Drag a node or lead to move it · Drag empty space to orbit · Scroll / pinch to zoom
Rate—bpm
PR—ms
QRS—ms
QT—ms
QTcF—ms
Axis*—°
Normal sinus rhythm25 mm/s · 10 mm/mV
0 ms
Intervals from tissue activation · Axis in model frame · Experimental morphology
WORKSPACE CONTROLS

The original workspace, rebuilt.

Orbit Left- or right-drag empty space. Scroll or pinch to zoom.
Move markers Left-drag SA, RA, LA, LL or a visible V electrode. Electrodes update the live signal during dragging; SA recalculates on release and snaps to tissue. Moving it outside the RA creates an experimental stimulus site.
Resize Drag the pane divider or control-panel edge. Double-click resets size; Escape cancels a drag. Focus a divider and use arrow keys for precise adjustment.
Dock Use the three icons in the control heading. Stack ECG keeps controls alongside the stacked viewers. Swap sides reverses the two viewers.
Camera views Front / Back / Left / Right / Top / Bot. Shift-click 1–3 to save; click to restore. Saved views persist locally.
Ortho views Front, side and top insets. Drag their dividers, scroll each inset to zoom, or click its label to flip it.
Paint Enable Paint tissue. Left-drag a stroke; right-drag to orbit. Choose scar, ischaemia or erase and a wall depth. Undo restores a stroke.
ECG Choose leads or switch grid/column. Drag the trace to scrub. Space plays/pauses. Resizing changes visible time, while paper squares retain their scale.

The new engine uses actual myocardial volumes. The original shell-based model imports need re-export through the Blender add-on. Models includes a tissue sphere and muscle strip. Their signals demonstrate tissue propagation, not normal cardiac ECG.

MODEL & METHODS

From anatomy to a signal.

A 48,000-triangle display surface is independent of 15,943 volume-weighted tissue nodes. Viewing, docking, resizing, opacity and paper gain do not change the calculated ECG.

Propagation and recovery

An event-driven graph simulates refractory tissue, AV gateways and an approximate fast endocardial layer. Stimulus and electrode positions are editable. Conduction changes recalculate in a background worker. Electrode potentials are sampled live; stored samples are never replaced.

One forward model

Volume-weighted voltage gradients supply nine electrode potentials. All twelve leads are derived from those same potentials, including the Wilson central terminal. Paper gain changes the drawing scale only.

Limits

This is an educational model with experimental morphology, not a clinically validated digital twin. The atlas simplifies atrial and RV walls. A homogeneous conductor, approximate conduction landmarks and simplified action potentials limit interpretation. Contraction is a visual animation, not a force or pressure model. The original tutorial course is not implemented.

Anatomy · CC BY 4.0 · Full model specification · Interaction reference