It is difficult to achieve a stably delicate operation in manual microsurgery, and the aim of this paper is to evaluate the robotic trephination that can open a promising perspective for the development of robotic microsurgical system for keratoplasty. A robot for corneal trephination integrating a force/torque sensor is designed based on manual trephine action. The manual experiments and the robotic experiments about penetrating trephination are performed in porcine eyes. The expected values of operational parameters that are references to the robotic trephination are obtained from the manual experiments using probability density functions (PDFs), including linear velocity, angular velocity, and rotating angle. Considering the meanings of the forces/torques, the results of the manual and robotic experiments such as trephine forces/torques and photomicrographs are compared to evaluate the effectiveness of robotic trephination. The manual trephination shows some randomness and this leads to large fluctuations in the trephine forces/torques during the surgery, but the robot may improve overall outcome of the graft, as it is able to carry out the operation stably and produce a uniform cutting margin. There is potential to improve the biomechanical properties in the delicate microsurgery by using the trephine robot and such devices can assist the surgeon to achieve a consistently high-quality result.

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Temperature of cooling roller is a key issue affecting the quality of the amorphous ribbon. To this end, heat flux distribution acting on cooling roller outer wall was calculated by fluid dynamics software Fluent. Cooling roller steady temperature field was analyzed with a finite element method with heat flux boundary conditions. The cooling roller inner and outer wall temperature distribution was obtained and the temperature of cooling roller as a function of cooling roller thickness and water passage height was discussed. Results show that cooling roller outer wall temperature decreases with roller thickness and the cooling water passage height decrease; cooling roller inner wall temperature decreases with roller thickness increases and the cooling water passage height decreases. Meantime, the appropriate roller thickness and passage height were selected to keep both inner and outer wall temperature of cooling roller within the certain range. The study result provides theoretical support for cooling roller design and optimization.