Study of the Mechanism of Perceived Rotational Acceleration of a Bionic Semicircular Canal on the Basis of the "Circular Geometry Hypothesis".

Academia often uses the "circular geometry hypothesis" to explain the sensing principle of the human SCC system for angular acceleration, which is widely accepted as an important angular acceleration sensor in the human balance system. Based on this hypothesis and the anatomical structure of human SCCs, a series of physical SCC models with different geometries at 4× magnification were prepared via 3D printing and modification of hydrogels. Theoretical models of the SCC perception mechanism were established. Then, impulse angular acceleration, sinusoidal rotation and sinusoidal linear stimulation were applied to the models, and their responses were visually observed and analyzed in detail. As a result, the circular SCC model had a larger system gain and a smaller phase difference for the angular acceleration stimulation but a smaller system gain and a larger phase difference for the linear acceleration stimulation. These results verified that the circular semicircular canal was more sensitive to angular acceleration.