SATO Tomomasa The University of Tokyo, Research Center for Advanced Science and Technology, Pr, 先端科学技術センター, 教授 (50235371)
HATAMURA Yotaro The University of Tokyo, Faculty of Engineering, Professor, 工学部, 教授 (40010863)
WATANABE Hiroyoshi National Fukuyama Hospital, Department of Orthopaedic Surgery, Doctor, 整形外科, 医師
|Budget Amount *help
¥9,000,000 (Direct Cost : ¥9,000,000)
Fiscal Year 1994 : ¥3,000,000 (Direct Cost : ¥3,000,000)
Fiscal Year 1993 : ¥6,000,000 (Direct Cost : ¥6,000,000)
This research has developed a tele-micro-surgery system with operational environment information transmission capability. The system consists of the following components : (i) a slave manipulator with a fixed operational point, (ii) a visual information acquisition system with a fixed visual point, and (iii) a master manipulator with a feature that moments are not fed back.
To perform micro-surgery by handling a pair of tweezers and needles as an operator's arbitrary intention, the "slave manipulator with a fixed operational point" consists of rough mechanism for wide range motion, fine mechanism for high precision and rotational degrees of freedom where all axs of rotation intersect at the tip of the tool. Because all apparatus, including the slave manipulators and the visual information system must share the limited space around the small object that is being handled by the system, each mechanism should be confined to a conical space. Therefore, actuators must be located at the outer
side of the mechanism and the motion of the actuator is transmitted though parallel link mechanism.
The "visual information acquisition system with a fixed visual point" has the following features : translational fine mechanism to move the operation point, rotational mechanism to get visual information from an arbitrary direction, keeping the center of the rotation in the visual field, zoom function for arbitrary magnification ratio, lighting equipment which is arranged so that it does not disturb the operation, wide range motion ability, and compactness to leave room for manipulators.
For the master manipulator the following functions are necessary : separation of rotational and translational degrees of freedom, augmented presentation function of force information in the micro world, holding function of tweezers for grasping a needle, posture keeping function when an operator is not handling, and constraint function to reduce the degrees of freedom. If it is assumed in the system that the tip of the tool is fixed, only translational force will occer and the moment is not generated. Therefore, only the translational force need be fed back to the force feedback type master manipulator. The rotational and translational degrees of freedom are realized by the combination of rotation rings and orthogonally combined linear guides, respectively.
By connecting the technologies mentioned above organically, a soft object with the diameter of 4mm was successfully sawed. Less