Natural orifice cholecystectomy using a miniature robot. Surg Endosc

N104 Walter Scott Engineering Center, University of Nebraska-Lincoln, P.O. Box 880656, Lincoln, NE 68588-0656, USA.
Surgical Endoscopy (Impact Factor: 3.26). 02/2009; 23(2):260-6. DOI: 10.1007/s00464-008-0195-3
Source: PubMed


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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    • "A possible solution to the limited dexterity consists of embedding controllable actuators inside the magnetic instruments. The most common approach reported in literature is adopting electromagnetic (EM) motors [7] [8] [9]. Since the available mechanical power in this kind of actuator scales with mass and volume, the motors that can fit through a single tiny incision have very limited power and do not allow surgeons to perform surgical tasks such as lifting an organ, or to tele-operate the instrument tip in realtime. "
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    ABSTRACT: Magnetic instruments for laparoscopic surgery have the potential to enhance triangulation and reduce invasiveness, as they can be rearranged inside the abdominal cavity and do not need a dedicated port during the procedure. Onboard actuators can be used to achieve a controlled and repeatable motion at the interface with the tissue. However, actuators that can fit through a single laparoscopic incision are very limited in power and do not allow performance of surgical tasks such as lifting an organ. In this study, we present a tissue retractor based on local magnetic actuation (LMA). This approach combines two pairs of magnets, one providing anchoring and the other transferring motion to an internal mechanism connected to a retracting lever. Design requirements were derived from clinical considerations, while finite element simulations and static modeling were used to select the permanent magnets, set the mechanism parameters, and predict the lifting and supporting capabilities of the tissue retractor. A three-tier validation was performed to assess the functionality of the device. First, the retracting performance was investigated via a benchtop experiment, by connecting an increasing load to the lever until failure occurred, and repeating this test for different intermagnetic distances. Then, the feasibility of liver resection was studied with an ex vivo experiment, using porcine hepatic tissue. Finally, the usability and the safety of the device were tested in vivo on an anesthetized porcine model. The developed retractor is 154mm long, 12.5mm in diameter, and weights 39.16 g. When abdominal wall thickness is 2 cm, the retractor is able to lift more than ten times its own weight. The model is able to predict the performance with a relative error of 9.06+/-0.52%. Liver retraction trials demonstrate that the device can be inserted via laparoscopic access, does not require a dedicated port, and can perform organ retraction. The main limitation is the reduced mobility due to the length of the device. In designing robotic instrument for laparoscopic surgery, LMA can enable the transfer of a larger amount of mechanical power than what is possible to achieve by embedding actuators on board. This study shows the feasibility of implementing a tissue retractor based on this approach and provides an illustration of the main steps that should be followed in designing a LMA laparoscopic instrument.
    No preview · Article · Mar 2015 · Journal of Medical Devices
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    • "A single module by itself cannot operate, but modules arranged together can achieve complex tasks and controlling such a system could be rather difficult. The surgical robots are commonly controlled from outside the patient's body under indirect video assisted vision with the use of a joystick-like surgical interface [4, 11, 12]. Snake-like modular mini-robots can be in some cases compared to flexible endoscopes. "
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    ABSTRACT: Aim. Modular mini-robots can be used in novel minimally invasive surgery techniques like natural orifice transluminal endoscopic surgery (NOTES) and laparoendoscopic single site (LESS) surgery. The control of these miniature assistants is complicated. The aim of this study is the in silico investigation of a remote controlling interface for modular miniature robots which can be used in minimally invasive surgery. Methods. The conceptual controlling system was developed, programmed, and simulated using professional robotics simulation software. Three different modes of control were programmed. The remote controlling surgical interface was virtually designed as a high scale representation of the respective modular mini-robot, therefore a modular controlling system itself. Results. With the proposed modular controlling system the user could easily identify the conformation of the modular mini-robot and adequately modify it as needed. The arrangement of each module was always known. The in silico investigation gave useful information regarding the controlling mode, the adequate speed of rearrangements, and the number of modules needed for efficient working tasks. Conclusions. The proposed conceptual model may promote the research and development of more sophisticated modular controlling systems. Modular surgical interfaces may improve the handling and the dexterity of modular miniature robots during minimally invasive procedures.
    Full-text · Article · Sep 2014 · Minimally Invasive Surgery
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    • "Adding more degrees of freedom is very useful for recent minimally invasive surgery such as Single Port Surgery(SPS) and NOTES[9]. Also sterilization and electrical safety are very important issue for clinical use. "
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    ABSTRACT: We have developed multi degrees of freedom forceps which has one degree of bending and one degree of tip rotation freedom for small USAD. Especially, we developed a ultrasonic motor for rotation mechanism, which has various merits of small size and high- torque. For actuation mechanism, we selected cylinder-type ultrasonic motor. Bulk piezoelectric zirconate titanate (PZT) cylinder was used as a stator transducer. Inner diameter and outer diameter of the actuator was 13 mm and 14 mm and length was 25 mm.In rotation property evaluation experiment, we confirmed that the actuator has sufficient rotation speed and holding torque. From positioning experiment, we have achieved smooth approach to the brood vessel model using the mechanism.
    Full-text · Article · Dec 2013
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