Natural orifice cholecystectomy using a miniature robot
ABSTRACT Natural orifice translumenal endoscopic surgery (NOTES) is surgically challenging. Current endoscopic tools provide an insufficient platform for visualization and manipulation of the surgical target. This study demonstrates the feasibility of using a miniature in vivo robot to enhance visualization and provide off-axis dexterous manipulation capabilities for NOTES.
The authors developed a dexterous, miniature robot with six degrees of freedom capable of applying significant force throughout its workspace. The robot, introduced through the esophagus, completely enters the peritoneal cavity through a transgastric insertion. The robot design consists of a central "body" and two "arms" fitted respectively with cautery and forceps end-effectors. The arms of the robot unfold, allowing the robot to flex freely for entry through the esophagus. Once in the peritoneal cavity, the arms refold, and the robot is attached to the abdominal wall using the interaction of magnets housed in the robot body with magnets in an external magnetic handle. Video feedback from the on-board cameras is provided to the surgeon throughout a procedure.
The efficacy of this robot was demonstrated in three nonsurvivable procedures in a porcine model, namely, abdominal exploration, bowel manipulation, and cholecystectomy. After insertion, the robot was attached to the interior abdominal wall. The robot was repositioned throughout the procedure to provide optimal orientations for visualization and tissue manipulation. The surgeon remotely controlled the actuation of the robot using an external console to assist in the procedures.
This study has shown that a dexterous miniature in vivo robot can apply significant forces in arbitrary directions and improve visualization to overcome many of the limitations of current endoscopic tools for performing NOTES procedures.
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ABSTRACT: This paper presents a novel articulated drive mechanism (ADM) for a multifunctional natural orifice transluminal endoscopic surgery (NOTES) robotic manipulator. It consists mainly of three major components including a snakelike linkage, motor housing, and an arm connector. The ADM can articulate into complex shapes for improved access to surgical targets. A connector provides an efficient and convenient modularity for insertion and removal of the robot. Four DC motors guide eight cables to steer the robot. The workspace, cable displacement and force transmission relationships are derived. Experimental results give preliminary validation of the feasibility and capability of the ADM system.Journal of Mechanisms and Robotics 02/2015; 7(1):0110041-110048. DOI:10.1115/1.4029307 · 0.86 Impact Factor
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ABSTRACT: We propose local magnetic actuation (LMA) as an approach to robotic actuation for surgical instruments. An LMA actuation unit consists of a pair of diametrically magnetized single-dipole cylindrical magnets, working as magnetic gears across the abdominal wall. In this study, we developed a dynamic model for an LMA actuation unit by extending the theory proposed for coaxial magnetic gears. The dynamic model was used for closed-loop control, and two alternative strategies-using either the angular velocity at the motor or at the load as feedback parameter-were compared. The amount of mechanical power that can be transferred across the abdominal wall at different intermagnetic distances was also investigated. The proposed dynamic model presented a relative error below 7.5% in estimating the load torque from the system parameters. Both the strategies proposed for closed-loop control were effective in regulating the load speed with a relative error below 2% of the desired steady-state value. However, the load-side closed-loop control approach was more precise and allowed the system to transmit larger values of torque, showing, at the same time, less dependence from the angular velocity. In particular, an average value of 1.5 mN·m can be transferred at 7 cm, increasing up to 13.5 mN·m as the separation distance is reduced down to 2 cm. Given the constraints in diameter and volume for a surgical instrument, the proposed approach allows for transferring a larger amount of mechanical power than what would be possible to achieve by embedding commercial dc motors.IEEE Transactions on Robotics 02/2015; 31(1):143-156. DOI:10.1109/TRO.2014.2382851 · 2.65 Impact Factor
Article: Flexible endoscopic robot[Show abstract] [Hide abstract]
ABSTRACT: Abstract Natural orifice transluminal endoscopic surgery (NOTES) is a novel surgical procedure during which abdominal operations can be performed with an endoscope passed through a natural orifice through an internal incision in the stomach, vagina, bladder or colon. NOTES is still evolving and many barriers stand on its way before it can gain acceptance in modern surgical practice. Effective access to the peritoneal cavity, closure techniques of the natural orifice access sites, development of a multitasking platform to accomplish procedures and support for special orientation are only a handful of its known limitations. Although the endoscope and conventional tools are useful for simple procedures, many important and complicated procedures are currently not possible due to limitation of degree of freedom (DOF) of the end effectors. We have developed a Master and Slave Transluminal Endoscopic Robot (MASTER) with nine degrees of freedom (DOF) in end effectors, which are long and flexible so as to enhance endoscopic procedures and NOTES. Using MASTER we have successfully performed endoscopic sub-mucosal dissections (ESD) to segmental hepatectomies in animal models. Thus, the MASTER robotic system shows great potential to perform new surgical procedures that are otherwise not possible with conventional endoscopic tools.Minimally Invasive Therapy & Allied Technologies 02/2015; 24(1):37-44. DOI:10.3109/13645706.2014.996163 · 1.18 Impact Factor