Abstract:In order to achieve the optical coherence tomography (OCT) scan of the esophagus, an endoscopic optical scanning mechanism that combines longitudinal motion of a linear ultrasonic motor and circumferential scanning of a rotating ultrasonic motor is developed. The linear motor is a squiggle- piezoelectric motor form New Scale Technologies. The rotating motor is a hollow shaft ultrasonic motor which works at the out-of-plane bending mode of the circular thin plate. The finite element software COMSOL Multiphysics is used to optimize the size of the rotating motor. The motor′s speed is 4 200 r/min under the driving signal of 78.5kHz, 60Vp-p sinusoidal voltage, which can be used in the endoscope when the OCT scanning laser is modulated at the frequency of 200kHz. The endoscopic optical scanning mechanism including the lens is designed, the diameter of the capsule endoscope prototype is 16mm, and the linear stroke is greater than 5mm. The medical equipment can be compatible with magnetic resonance imaging (MRI) for using piezoelectric ultrasonic motor.