Performing medical gestures under MRI is a promising medical approach. Todate, using MRI for interventions is still limited, despite the quality of the provided images. This limitation is mainly due to the confined physical space inside the tunnel and the complexity of the gestures. To make accessible such practices, a robotic assistance seems very relevant. However, it’s a challenge for the designer, given the limited space and the strong magnetic field inside the bore. In this context, we have developed an MR-‐compatible robotic assistant, named MRGuide, for prostate interventions. The robot is based on an original cable-‐ driven manipulator with a remote actuation. In this work, many contributions leading to the development of MRGuide are presented. One of these contributions lies in the use of an original instrumented structure to evaluate the cables tensions. This instrumentation is based on the use of a truss structure, compliant mechanisms and optical displacement sensors for MRcompatibility. In order to optimize the size of the robot and facilitate its integration in the scanner, a new design methodology using interval analysis has been developed. Other contributions related to the workspace characterization of instrumented cable-‐driven robots, the tension sensor calibration and the development of a new control strategy adapted to the device are described.
