Medical Device Simulators

Gamma Knife

Explore how multiple idealized beam axes converge at a selected focus in a two-dimensional normalized model.

Educational use only. This is not a Gamma Knife treatment-planning system and cannot be used for clinical decisions, prescriptions, dose, or targeting. Every result is a normalized relative contribution—not Gy.

Idealized geometry

Beam controls

Target x0.0 a.u.Target y0.0 a.u.Beam count, N12 beamsAngular spread360 °Beam spread, σ0.80 a.u.Add a conceptual second focus

Why these controls?

These controls arrange the idealized beam geometry: target position, number of beams, angular spread, beam width σ and relative weights. Change them to see how convergence builds a high contribution at the focus while any single beam stays low everywhere.

Normalized map

Relative beam convergence

12 beams

1 focus

Axes intersect at the selected conceptual focus; contours are teaching guides.

At selected target

1.000

Offset point (+3, +3)

0.130

Raw sum at target

12.00

Color bands and dashed rings are normalized visual layers. Beam-axis lines show ideal geometry; off-target contribution is not zero.

Teaching equation

D_rel(x,y) = Σ w_k exp[−d_k²/(2σ²)]

d_k is perpendicular distance to beam axis k. N is beam count, w_k is relative weight, and σ is effective beam spread.

Student checks

Confirm one beam is maximal along its entire axis.
Compare one beam with symmetric convergence at the focus.
Reduce σ and observe a narrower distribution.
Move the target and confirm the convergence maximum moves.
Reduce one group’s weight and inspect the loss of symmetry.
Explain why nonzero off-target contribution requires real planning safeguards.