Teleoperated medical robotic systems allow procedures such as surgeries, treatments, and diagnoses to be conducted across short or long distances while utilizing wired and/or wireless communication networks. This study presents a systematic review of the relevant literature between the years 2004 and 2015, focusing on medical teleoperated robotic systems which have witnessed tremendous growth over the examined period. A thorough insight of telerobotics systems discussing design concepts, enabling technologies (namely robotic manipulation, telecommunications, and vision systems), and potential applications in clinical practice is provided, while existing limitations and future trends are also highlighted. A representative paradigm of the short-distance case is the da Vinci Surgical System which is described in order to highlight relevant issues. The long-distance telerobotics concept is exemplified through a case study on diagnostic ultrasound scanning. Moreover, the present review provides a classification into short- and long-distance telerobotic systems, depending on the distance from which they are operated. Telerobotic systems are further categorized with respect to their application field. For the reviewed systems are also examined their engineering characteristics and the employed robotics technology. The current status of the field, its significance, the potential, as well as the challenges that lie ahead are thoroughly discussed.

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Medical telerobotic systems: current status and future trends.

This paper presents a new type of 4-degree-of-freedom (DOF) robotic surgical instrument for a minimally invasive surgical robot system. The forceps wrist mechanism was designed here on the basis of the 3-DOF parallel structure with three prismatic-spherical-revolute kinematic chains. The pitch and yaw motions of the moving platform generated the wrist rotational motions of the forceps. The axial translation of the parallel mechanism was converted into the forceps grasp motion by an inversion of the slider-crank mechanism. Furthermore, for a more dexterous movement of the forceps, a full revolution of the forceps for the axial rotation is also possible with the instrument. While the proposed instrument realized all the required DOFs of a forceps, the parallel structure of the wrist and the driving mechanism that was designed using only rod elements made the proposed instrument more reliable and rigid than other wire-driven instruments. The kinematic constraints and inverse kinematics of the proposed instrument were derived. Furthermore, the screw-based Jacobian was formulated geometrically, and the static force relation and the linear constraints on a twist were derived. Finally, a prototype of the proposed instrument with a diameter of 8 mm was introduced, and the performance of the prototype was verified through several experiments.

Design of a Novel 4-DOF Wrist-Type Surgical Instrument With Enhanced Rigidity and Dexterity

Motion-canceling bilateral control, a teleoperation method, is proposed and implemented for telesurgical robots. Telesurgical robots have difficulty in achieving control owing to a lack of haptic feedback and the beating motion of organs. Hence, this study aims to provide a surgeon with the means for feeling the tactile sensation of the remote organ, as well as synchronizing with its motion. Therefore, a surgeon can treat the target using a master robot as if the organ is not moving even though it actually moves. The proposed method basically consists of acceleration-based bilateral control to achieve haptic feedback, and visual servoing is used to compensate for organ motion. The frequency characteristics and root locus of the proposed method are analyzed to evaluate its performance and stability, respectively. The proposal is validated through experiments using telesurgical forceps robots.

Heartbeat Synchronization With Haptic Feedback for Telesurgical Robot

Experimental evaluation of an eco-friendly grinding process combining minimum quantity lubrication and graphene-enhanced plant-oil-based cutting fluid

Review of snake robots in constrained environments

Background

Robot-assisted systems have been widely used in minimally invasive surgery (MIS) practice, and with them the precision and accuracy of surgical procedures can be significantly improved. Promoting the development of robot technology in MIS will improve robot performance and help in tackling problems from complex surgical procedures.



Methods

A medical robot system with a new mechanism for MIS was proposed to achieve a two-dimensional (2D) remote centre of motion (RCM). An improved surgical instrument was designed to enhance manipulability and eliminate the coupling motion between the wrist and the grippers. The control subsystem adopted a master–slave control mode, upon which a new method with error compensation of repetitive feedback can be based for the inverse kinematics solution. A unique solution with less computation and higher satisfactory accuracy was also obtained. Tremor filtration and trajectory planning were also addressed with regard to the smoothness of the surgical instrument movement.



Results

The robot system was tested on pigs weighing 30–45 kg. The experimental results show that the robot can successfully complete a cholecystectomy and meet the demands of MIS.



Conclusions

The results of the animal experiments were excellent, indicating a promising clinical application of the robot with high manipulability. Copyright © 2011 John Wiley & Sons, Ltd.

Development of a medical robot system for minimally invasive surgery

Robot-assisted minimally invasive surgery (RMIS) is promising for improving surgical accuracy and dexterity. As the end effector of the robotic arm, the remote centre of motion mechanism is one of the requisite terms for guaranteeing patient safety. The existing remote centre of motion mechanisms are complex and large in volume, as well as high assembly requirement and unsatisfactory precise. This paper aimed to present a new remote centre of motion mechanism for solving these problems. A new mechanism based on the RMIS requirements is proposed for holding the laparoscope and generating a remote centre of motion for the laparoscope. The mechanism kinematics is then analysed from the perspective of the structural function, and its inverse kinematics is determined with a small number of calculations. Finally, the position deviation of the laparoscope rotational point is chosen as the index to evaluate the mechanism performance. The experiments are performed to test the deviation. The position deviations of the laparoscope rotational point do not exceed 2 mm, which is lower than that of the existing remote centre of motion mechanism. The 2 mm positioning error of the laparoscope won’t affect surgeon observation of the surgical field, and the pressure caused by the positioning error was acceptable for the skin elasticity. The proposed mechanism meets the RMIS requirement. The proposed mechanism can achieve the remote centre of motion for the laparoscope. Its simple and compact structure is beneficial to avoid the collision of robotic arms, and it can be applied on other robots for providing the instrument necessary motion in minimally invasive surgery.

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New remote centre of motion mechanism for robot-assisted minimally invasive surgery

Background
Pose optimization and port placement are critical issues for preoperative preparation in robot-assisted minimally invasive surgery (RMIS), and affect the robot performance and surgery quality.

Methods
This paper proposes a method for pose optimization and port placement for RMIS in cholecystectomy that considers both the robot and surgery requirements. The robot pose optimization was divided into optimization of the positioning joint configuration and optimization of the end effector configuration. To determine the optimal location for the trocar port placement, the operational workspace was defined as the evaluation index. The port area was divided into many sub-areas, and that with the maximum operational workspace was selected as the location for the port placement.

Results
Considering the left robotic arm as an example, the location for the port placement and joints angles for robotic arm configuration were discussed and simulated using the proposed method.

Conclusion
This research can provide guidelines for surgeons in preoperative preparation.

Pose optimization and port placement for robot-assisted minimally invasive surgery in cholecystectomy

Background Surgical instruments greatly impact the performance of robot-assisted minimally invasive surgery (RMIS) because they operate on tissues. Methods A snake-like surgical instrument, designed with 4 degrees of freedom (DOFs), is proposed for RMIS. The DOFs are as follows: opening and closing motions of the forceps, rotation of the forceps and bi-directional bending of the instrument. The performance of the instrument was evaluated using a prototype in vitro. Results All DOFs of the instrument were experimentally evaluated and proven sufficient for RMIS. In vitro testing showed that the operations of the proposed model were powerful and steady. Conclusions The position and posture of the surgical instrument could be adjusted in the body of the patient by its bending and rotational movements. The proposed model could therefore work as a competent assistant in multi-port RMIS and allow surgeons to perform better.

Snake-like surgical forceps for robot-assisted minimally invasive surgery.

Compound sinusoidal grid surface with nanometric finish plays a significant role in modern systems and precision calibrator, which can make the systems smaller, the system structure more simple, reduce the cost, and promote the performance of the systems, but it is difficult to design and fabricate by traditional methods. In this paper, a compound freeform surface constructed by a paraboloidal base surface and sinusoidal grid feature surface is designed and machined by slow tool servo (STS) assisted with single point diamond turning (SPDT). A novel combination of the constant angle and constant arc-length method is presented to optimize the cutting tool path. The machining error prediction model is analyzed for fabricating the compound sinusoidal grid surface. A compound sinusoidal grid surface with 0.03 mm amplitude and period of 4 is designed and cutting process is simulated by use of MATLAB software, machining experiment is done on ultra-precision machine tool, the surface profile and topography are measured by Taylor Hobson and Keyence VR-3200, respectively. After dealing with the measurement data of compound freeform surface, form accuracy 4.25 μm in Peak Village value (PV), and surface roughness 89 nm in Ra are obtained for the machined surface. From the theoretical analysis and experimental results, it can be seen that the proposed method is a reasonable choice for fabricating the compound sinusoidal grid surface.

Mei Feng

Papers

Development of a medical robot system for minimally invasive surgery

New remote centre of motion mechanism for robot-assisted minimally invasive surgery

Pose optimization and port placement for robot-assisted minimally invasive surgery in cholecystectomy

Snake-like surgical forceps for robot-assisted minimally invasive surgery.

Ultra-Precision Machining of a Compound Sinusoidal Grid Surface Based on Slow Tool Servo