Design and analysis of a novel long-distance double tendon-sheath transmission device for breast intervention robots under MRI field

Cancer represents a major threat to human health. Magnetic resonance imaging (MRI) provides superior performance to other imaging-based examination methods in the detection of tumors and offers distinct advantages in biopsy and seed implantation. However, because of the MRI environment, the material requirements for actuating devices for the medical robots used in MRI are incredibly demanding. This paper describes a novel double tendon-sheath transmission device for use in MRI applications. LeBus grooves are used in the original transmission wheels, thus enabling the system to realize long-distance and large-stroke transmission with improved accuracy. The friction model of the transmission system and the transmission characteristics model of the novel tendon-sheath structure are then established. To address the problem that tension sensors cannot be installed in large-stroke transmission systems, a three-point force measurement method is used to measure and set an appropriate preload in the novel tendon-sheath transmission system. Additionally, experiments are conducted to verify the accuracy of the theoretical model and multiple groups of tests are performed to explore the transmission characteristics. Finally, the novel tendon-sheath transmission system is compensated to improve its accuracy and the experimental results acquired after compensation show that the system satisfies the design requirements

SpiderNet: A multi-server code service model design for computational grid support.

One goal of a Computational Grid is to aggregate ensembles of shared, heterogeneous, and distributed resources to provide computational power [Foster00]. The increasing use of Web technology Internet and Intranet is making the Web an attractive framework for solving distributed applications, in particular, because the interface can be made platform independent. Several systems have been developed that make distributed computing available. However, these systems are either not web-based or not taking the enterprise Java technology [Chen97]. Typically, those systems are unnecessarily complicated and require long development. This thesis is an approach to research and development on distributed, multi-server code service system model---SpiderNet. While a service-based architecture for distributed computer systems is not new, a theory and practice approach on using EJB in multi-server environment is presented in this thesis report. It adapts enterprise Java and web application server technology trying to solve the fundamental problem of multi-server model: work balance for efficiency and fail over for availability. This thesis also demonstrates that with using Web and enterprise Java development toolkit, it is possible to build applications using a graphical drag-and-drop and web-based interface, thereby speeding up the application development. Source: Masters Abstracts International, Volume: 40-06, page: 1560. Adviser: Robert D. Kent. Thesis (M.Sc.)--University of Windsor (Canada), 2001