Mechanical Stabilization in Robotic Bionic Eyes with Gravity and Disturbance Compensations The vibration of the robot during the movement brings various irregular motion disturbances to the robotxe2x80x99s head, these vibration results into unstable images captures by the headmounted vision system and therefor the vision system cannot accurately perceive the environment. This paper presents a mechanical stabilization method based on gravity and disturbance compensations, which considers and compensates the gravity influences of the mechanical structure and external disturbances. Finally, the current command of the joint motor is generated based on the compensations, which can quickly stabilize the image. We performed simulation and physical experiments to verify the performance of our proposed method.

Towards securing the sclera against patient involuntary head movement in robotic retinal surgery Retinal surgery involves manipulating very delicate tissues within the confined area of eyeball. In such demanding practices, patient involuntary head movement might abruptly raise tooltoeyeball interaction forces which would be detrimental to eye. This study is aimed at implementing different force control strategies and evaluating how they contribute to attaining sclera force safety while patient head drift is present. To simulate patient head movement, a piezoelectricactuated linear stage is used to produce random motions in a single direction in random time intervals. Having an eye phantom attached to the linear stage then an experienced eye surgeon is asked to manipulate the eye and repeat a mock surgical task both with and without the assist of the SteadyHand Eye Robot. For the freehand case, warning sounds were provided to the surgeon as auditory feedback to alert him about excessive slclra forces. For the robotassisted experiments two variants of an adaptive sclera force control and a virtual fixture method were deployed to see how they can maintain eye safety under head drift circumstances. The results indicate that the developed robot control strategies are able to compensate for head drift and keep the sclera forces under safe levels as well as the free hand operation.