Kinematic optimization of a spherical mechanism for a minimally invasive surgical robot.

Lum, M.J.H. and Rosen, J. and Sinanan, M. and Hannaford, B. (2004) Kinematic optimization of a spherical mechanism for a minimally invasive surgical robot. In: Proc. IEEE International Conference on Robotics and Automation.

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Advances in surgical technology allow physicians to more effectively provide care to their patients. Minimally invasive surgery (MIS) has revolutionized the way a significant number of procedures are performed. Recent advances in technology have led to the fusion of MIS techniques and robot devices. Current systems are large and cumbersome. By optimizing a spherical mechanism using in-vivo data collected during MIS procedures, this paper is focused on a bottom-up approach in developing a new class of surgical robot arms. The spherical mechanism is a rotational manipulator with all axes intersecting at the center of the sphere. Locating the rotation center of the mechanism at the MIS port makes this class of mechanism a suitable candidate for the first two links of a surgical robot for MIS. The required dexterous workspace (DWS) is defined as a high dexterity region defined by a right circular cone with a vertex angel of 60 deg in which 95 of the tool motions are contained based on in-vivo measurements. The extended dexterous workspace (EDWS) is defined as the workspace required to reach the entire abdominal cavity with MIS instruments and defined by a cone with an elliptical cross section created by two orthogonal vertex angels of 60 deg and 90 deg . For optimizing the mechanism structure, the forward and inverse kinematics as well as the Jacobian matrix were derived. Using the Jacobian, mechanism isotropy was considered as the performance metric. Optimization across both the DWS and a superset of the EDWS lead to a mechanism configuration with link length angles of 52 deg and 40 deg that maximizes kinematic performance and compactness. The workspace of this design covers the entire EDWS. By directly applying in-vivo experimental data from MIS in order to optimize the spherical manipulator, a design that maximizes performance and minimizes size has been developed. A pair of prototype manipulators will be developed based on these results.

Item Type: Conference or Workshop Item (Paper)
Subjects: B Teleoperation > B Teleoperation (General)
Depositing User: Junjie Yan
Date Deposited: 09 Jul 2015 23:40
Last Modified: 09 Jul 2015 23:40

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