Design and Validation of Multi-Layer Brakes for a Lockable Stand for a Surgical Robotic SystemBehaviors

MPL (multi-port laparoscopy) has mostly replaced traditional open surgery due to several advantages, such as less postoperative complications and faster recovery. However, manual manipulation of the laparoscopic surgical tools can be challenging and exhausting. Numerous robotic systems were hence developed to assist surgeons. A majority of the existing developments followed a similar approach that a manipulator maneuvers a stick-like surgical tool for intra-abdominal surgical tasks. The surgical tool is usually equipped with a wrist for distal dexterity, while the manipulator is required to realize RCM (Remote Center of Motion) movements in order to prevent the surgical tool from tearing a patient's abdominal wall. However, a continuum surgical manipulator with 6 DoFs (Degrees of Freedom) can provide sufficient mobility for intra-abdominal movements. Therefore, only a lockable stand that holds such a continuum surgical manipulator, instead of an RCM mechanism, is needed during a procedure. Compact and reliable joint brakes with high locking torques and rapid actuation are needed for such a lockable stand. Inspired by the layered jamming principle, this paper presents the design, construction and verification of multi-layer brakes for the lockable stand. The experimental validation of the multi-layer brakes is elaborated to demonstrate the functionality and the effectiveness of the proposed idea.