Coupling Effect Suppressed Compact Surgical Robot with 7-Axis Multi-Joint Using Wire-Driven Method

Abstract

Currently, the most prevalent surgical treatment method is laparoscopic surgery. Robotic surgery has many advantages over laparoscopic surgery. Therefore, robotic surgery technology is currently constantly evolving. The advantages of robotic surgery are that it can minimize incision, bleeding, and sequelae. Other advantages of robotic surgery are that it can reduce hospitalization, recovery period, and side effects. The appeal of robotic surgery is that it requires fewer surgical personnel compared to laparoscopic surgery. This paper proposes an ultra-compact 7-axis vertical multi-joint robot that employs the wire-driven method for minimally invasive surgery. The proposed robot analyzes the degree of freedom and motion coupling for control. The robot joint is composed of a total of seven joints, and among them, the 7-axis joint operates the forceps. At this time, the forceps joint (#7 axis) can only operate open and close functions, while the link is bent and rotatable, regardless of position change. This phenomenon can be analyzed by Forward Kinematics. Also, when the DOF rotates, the passing wires become twisted, and the wire is generated through length change and coupling phenomenon. The maximum rotation angle of DOF is 90° and the rotating passing wire is wound by the rotation of the wire pulley. If the DOF is rotated to the full range of 120°, the second DOF will be rotated to 90°, and at this time, the coupling phenomenon caused by the first DOF rotation can be eliminated. The length change and the robot joint angle change related to the motor drive, based on the surgical robot control using the wire-driven method, are correlated, and the values for the position and direction of the end effector of the robot can be obtained through a forward kinematic analysis. The coupling problem occurring in the wire connecting the robot driving part can be solved through a kinematic analysis. Therefore, it was possible to test the position of the slave robot and the performance of the surgical forceps movement using the master system.

Proposed Shaft Coupling Based on RPRRR Mechanism: Positional Analysis and Consequences

“…From the presented considerations, it results that, for an accurate design of the mechanism, the envelopes of the segments 𝛥 and 𝛥 described with respect to element 4 and 3, respectively, must be found. These can be obtained by applying relations (36) and (40), because the parameters 𝑥 , 𝑧 , 𝑥 , and 𝑧 , respectively, must be chosen in a manner that the points of coordinates 𝑥 , 𝑦 and 𝑥 , 𝑦 are placed on the segments 𝛥 and 𝛥 respectively. The illustration of the procedure is shown in Figures 14 and 15 From the designing point of view, there are two important aspects:…”

“…Relation ( 35) is developed; therefore, the parametric equations of the trajectory of a point from the plane x 3 z 3 in the plane x 4 z 4 are obtained: In Figure 9, the trajectory of the origin of the system O 3 x 3 y 3 z 3 in the plane x 4 z 4 attached to element 4 is plotted, as in the particular case x 3 = 0; z 3 = 0 in relation (36). To find the rotation motion from the pair, it is sufficient to specify the variation in time of the angle between two straight lines belonging to the planes that form the planar pair.…”

“…Two main directions are met in engineering applications: either the final element belongs to a mechanism and therefore the kinematics will depend on the motion of the driving element and on the constructive parameters of the mechanism, or the final element appertains to a robotic structure wherein the binary elements present a simple shape [24][25][26] (open kinematic chain) and the motion of the final element is ensured by the action of multiple driving pairs from the structure of the robot [27]-with the well-known examples of multiple-axes CNC machines [28,29] and medical devices and robots [30][31][32][33][34][35][36]. Contrasting with the robotic kinematic chain, in the case of mechanisms, the task of obtaining an imposed motion law of the final element is more difficult due to the fact that the driving element performs a simple motion.…”

Mathematical Analysis and Motion Capture System Utilization Method for Standardization Evaluation of Tracking Objectivity of 6-DOF Arm Structure for Rehabilitation Training Exercise Therapy Robot

“…In each joint, the , , and axes that are the movement coordinate systems were mapped to the joint . The links and rotation parameters based on the forward kinematics are shown in Table 1 and were determined from the Denavit–Hartenberg proof [ 22 , 23 ]. In particular, is the rotation joint and directly concerns the rehabilitation exercise.…”

Adjustment of the Length Variation With Wire-driven Using the Stand Looper Tension Technique for Surgical Robot Applications

“…1 Although the wire-driven approach minimizes a robot size and weight, discrepancies may arise when the wire lengths for pulling and pushing motions is not match, affecting power transmission for joint movement. 2,3 To address this challenge, this study proposes a technique of implementing looper strip tension between stands as an alternative to the wire-driven method. Consequently, mathematical analyses and simulations are conducted to examine the potential for error minimization.…”