Contents I. Introduction
The MRI based medical diagnosis and treatment paradigm capitalizes on the novel benefits and capabilities created by the combination of high sensitivity for detecting tumors, high spatial resolution and high-fidelity soft tissue contrast. This makes it an ideal modality for guiding and monitoring medical procedures, such as needle biopsy and low-dose-rate permanent brachytherapy. Though with so many appealing merits, the magnetic and electrical fields in MRI environment presents significant challenges for mechatronic instrumentation design. Generally, the development of sensors for applications in MR environments requires careful consideration of safety and electromagnetic compatibility constraints. Fig. 1 illustrates a diagram of a traditional transrectal ultrasound guided (TRUS) brachytherapy needle placement procedure which is structurally similar to our application in [1]. Our previous work in [2] has developed an MRI-compatible actuation system, specifically targeting the neural intervention procedure, we intend to extend this work to sensor design to further our systematic approach to developing MR-compatible mechatronic systems. Specifically, for soft tissue needle placement, our basic measurement requirement is 3 axis hybrid sensing-one force and two torque measurements and the details would be explained in Section II.
