Fig. 3.

Hysteresis characterization method using OCE. (a) Workflow of the hysteresis characterization method based on the separate measurements of the air-pulse and surface displacement profiles. (b) and (c) are based on a hysteresis characterization example, where (b) shows the normalized air pressure (mean ± SD) and surface displacement profiles in the time domain and (c) demonstrates the hysteresis loop based on the measurement of the pressure-displacement relations in the loading and unloading periods. In this example, the sample was a 2% agar phantom, the air pressure was 8 Pa, and the maximum induced surface displacement was 1.84 µm at a measurement distance of 0.15 mm from the stimulation center.