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ABSTRACT: BACKGROUND: Laparoscopic surgery is becoming increasingly popular throughout the world. But the conventional instruments used in many surgeries are not flexible enough to be operated. Challenging tasks, such as suturing and knot-tying tasks are difficult to complete using conventional instruments with limited degrees of freedom (DoFs). In the paper, a novel cable-driven multi-DoF manual instrument is presented with a simple structure but strong functionality. METHODS: The proposed instrument has been developed with a wristlike operation end (OE), a wristlike end effector (EE), and the transmission system. It can be operated intuitively. The orientation and the position of the EE are directly controlled by surgeons due to the one-to-one motion mapping structure. The clamp structure and tension device are reasonably designed. The pitch, yaw, and the open and close motion are actuated by cables. Based on the optimization index Global Condition Index (GCI), four cables are used to actuate the pitch and yaw motions, while other two are used for the open and close motion. The layout of the cables is also determined by the GCI. RESULTS: Experiments carried out with a prototype show that tasks such as suturing and knot-tying can be completed comfortably. Due to the intuitive control and multi-DoFs, surgeons can use the prototype to finish the tasks with ease. CONCLUSIONS: The instrument developed herein with intuitive control and dexterity can be used alone or together with a robotic system to accomplish some challenging tasks that are difficult for conventional instruments. Copyright © 2012 John Wiley & Sons, Ltd.
International Journal of Medical Robotics and Computer Assisted Surgery 04/2012; · 1.59 Impact Factor
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ABSTRACT: Minimally invasive surgery (MIS) robots are commonly used in hospitals and medical centres. However, currently available robotic systems are very complicated and huge, greatly raising system costs and the requirements of operating rooms. These disadvantages have become the major impediments to the expansion of MIS robots.
An integrated MIS robotic system is proposed based on the analysis of advantages and disadvantages of different MIS robots. In the proposed system, the master manipulators, slave manipulators, image display device and control system have been designed as a whole. Modular design is adopted for the control system for easy maintenance and upgrade. The kinematic relations between the master and the slave are also investigated and embedded in software to realize intuitive movements of hand and instrument. Finally, animal experiments were designed to test the effectiveness of the robot.
The robot realizes natural hand-eye movements between the master and the slave to facilitate MIS operations. The experimental results show that the robot can realize similar functions to those of current commercialized robots.
The integrated design simplifies the robotic system and facilitates use of the robot. Compared with the commercialized robots, the proposed MIS robot achieves similar functions and features but with a smaller size and less weight.
International Journal of Medical Robotics and Computer Assisted Surgery 03/2012; 8(1):77-84. · 1.59 Impact Factor
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ABSTRACT: BACKGROUND: Compared with conventional minimally invasive surgery and open surgery, robotic-assisted minimally invasive surgery can overcome or eliminate drawbacks caused by operator restrictions, motion limitation by the trocar and the image system, such as fatigue, trembling, low precision, constrained degree-of-freedom, poor hand-eye coordination and restricted surgical vision. In this paper, a novel partly tendon-driven master-slave robot system is proposed to assist minimally invasive surgery and a master-slave control architecture is developed for abdominal surgical operations. METHODS: A novel master-slave surgery robot system named MicroHand A has been developed. A kinematic analysis of master and slave manipulators was conducted, based on screw theory and vector loop equation. The relationships of the tendon-driven multi-DOF surgical instrument among Cartesian space, actuator space and joint space were derived for control purposes. The control system architecture of the MicroHand A was designed with intuitive motion control and motion scaling control. Llewellyn's absolute stability criterion and the transparency of the one-DOF master-slave system are also analysed. RESULTS: Intuitive motion control under dissimilar kinematics in master-slave manipulations and motion scaling control were accomplished to solve absonant hand-eye coordination, kinematic dissimilarity and workspace mismatch of master-slave manipulator problems. A series of tests and animal experiments were carried out to evaluate system performance. The experimental results demonstrate that the system could accomplish intuitive motion control and motion scaling control, and that the control system is stable and reliable. CONCLUSIONS: The experiments performed on the MicroHand A robotic system yielded expected control results. The system satisfies the requirements of minimally invasive surgery. Intuitive motion control and motion scaling control under different kinematics for the master and slave have been implemented. Copyright © 2011 John Wiley & Sons, Ltd.
International Journal of Medical Robotics and Computer Assisted Surgery 07/2011; · 1.59 Impact Factor
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IEEE International Conference on Robotics and Automation, ICRA 2011, Shanghai, China, 9-13 May 2011; 01/2011
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ABSTRACT: The trajectory tracking control of 3-DOF instrument is very important for master-slave control robotic-assisted minimally invasive surgery. In this paper, dynamic structure and equation of motion for the 3-DOF instrument was established to use the Euler-Lagrange method based on screw theory. A control scheme is designed based on the computed-torque controller and a RBF neural network based compensating controller, which makes full used of the model-based control approach and uses the RBF neural network controller to compensate for the 3-DOF instrument modeling uncertainties. Dynamic trajectory tracking control simulations are carried out on a 3-DOF instrument. The simulations results demonstrate validity of the derived model and show excellent tracking capability of the designed control scheme.
Robotics and Biomimetics (ROBIO), 2009 IEEE International Conference on; 01/2010
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ABSTRACT: Minimally invasive surgery (MIS) has many advantages compared with open surgery, but there are still many drawbacks in performing MIS. Using robotic technologies, many problems caused by human restrictions, such as fatigue and low precision, can be solved. In this paper, a novel mechanism for a MIS robot is proposed.
Kinematics analysis was carried out and singularity and isotropy configurations were also investigated, based on kinematics equations. In order to evaluate the performance of the robot, a combined measure gave attention to the mean value and standard deviation of the reciprocal of the condition number. Optimization was achieved by maximizing the combined measure subjected to a set of constraints in the task workspace. The effectiveness of the measure was demonstrated by comparing the performance and volume of the optimized mechanism with those of the mechanism optimized by the Global Condition Index (GCI).
The robot met the volume constraints with the dimensional parameter a <or= 115 mm. The combined measure phi was maximized when a is 100 mm. The robots optimized by the GCI and the combined measure showed similar performance in terms of condition number, but the latter had advantages on volume compared with the former.
A novel mechanism that satisfied the incision point constraint of MIS was proposed. A systematic methodology for optimizing the mechanism was developed and the combined measure was effective to evaluate the performance. A prototype was set up based on the outcomes mentioned in the paper.
International Journal of Medical Robotics and Computer Assisted Surgery 12/2009; 6(1):83-90. · 1.59 Impact Factor
