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Semicircular canals — each ear from its side; the patient and the canals from above (schematic, not to scale)
Choose Canal to stimulate one canal, or Otoconia for BPPV. Click a canal in the drawing: once ampullopetal, twice ampullofugal, a third time at rest — several canals combine, e.g. both PCs (ampullofugal) → pure upbeat; AC+PC of one ear → pure torsion. AC/PC pairs lie in the LARP / RALP planes (~45° to the sagittal plane).
Canal
Ear
Flow of endolymph — click again to stop it
Which canal
Which ear
Otoconia — click a lit one again to remove them; or drag them from the dish
Head position
Several canals: each keeps its own flow and the responses add as vectors.
Click a canal to step it: ampullopetal → ampullofugal → at rest.
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Extraocular muscles — examiner's view (patient's right eye on your left)
Excited muscles glow coral; their antagonists (inhibited) turn blue.
Excited / contracting
Inhibited / relaxing
Not driven by this canal
Anatomical actions vs clinical testing (H-pattern)
Right eye, anterior view. A muscle's anatomical action (left) is its pull acting alone; clinical testing (right) first turns the eye so one muscle's action is isolated: SR/IR are tested in ABduction, SO/IO in ADduction. Click a muscle above to highlight its arrows here.
Which canal
Horizontal canal — where
Affected ear
Watch from
Epley outcome
Zuma outcome
Semont outcome
Yacovino outcome
The Epley's third position decides it
Head from above
Inside the canal
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