Dong-Yeop Seok

A Novel Six-Axis Force/Torque Sensor for Robotic Applications

This paper presents a novel six-axis force/torque (F/T) sensor for robotic applications that is self-contained, rugged, and inexpensive. Six capacitive sensor cells are adopted to detect three normal and three shear forces. Six sensor cell readings are converted to F/T information via calibrations and transformation. To simplify the manufacturing processes, a sensor design with parallel and orthogonal arrangements of sensing cells is proposed, which achieves the large improvement of the sensitivity. Also, the signal processing is realized with a single printed circuit board and a ground plate, and thus, we make it possible to build a lightweight six-axis F/T sensor with simple manufacturing processes at extremely low cost. The sensor is manufactured and its performances are validated by comparing them with a commercial six-axis F/T sensor.

Development of a grasping force-feedback user interface for surgical robot system

This paper presents a grasping force-feedback user interface (GFUI) which transfers the accurate kinesthetic force detected during robot-assisted minimally invasive surgery (RMIS) to a user, and allows the users to perform grasping motions with articulation and intuition. Using the GFUI, a developed robot hardware (S-surge) is controlled, and the force data measured from the robot are reflected to the GFUI. To evaluate the effect of grasping force-feedback control using the GFUI, a group of subjects (n=10) participated in a standard peg transfer tasks with and without the feedback control. To conduct the tasks, a developed robot hardware and a commercial haptic device were used which make the entire surgical environment including the GFUI as a master-slave controlled system. As a result, the performance of the GFUI was verified through the conducted tasks using the entire surgical system.

S-Surge: Novel Portable Surgical Robot with Multiaxis Force-Sensing Capability for Minimally Invasive Surgery

To achieve a compact and lightweight surgical robot with force-sensing capability, in this paper, we propose a surgical robot called “S-surge,” which is developed for robot-assisted minimally invasive surgery, focusing mainly on its mechanical design and force-sensing system. The robot consists of a 4-degree-of-freedom (DOF) surgical instrument and a 3-DOF remote center-of-motion manipulator. The manipulator is designed by adopting a double-parallelogram mechanism and spherical parallel mechanism to provide advantages such as compactness, simplicity, improved accuracy, and high stiffness. Kinematic analysis was performed in order to optimize workspace. The surgical instrument enables multiaxis force sensing including a three-axis pulling force and single-axis grasping force. In this study, it will be verified that it is feasible to carry the entire robot around thanks to its light weight (4.7 kg); therefore, allowing the robot to be applicable for telesurgery in remote areas. Finally, it will be explained how we experimented with the performance of the robot and conducted tissue manipulating task using the motion and force sensing capability of the robot in a simulated surgical setting.

A new type of surgical forceps integrated with three-axial force sensor for minimally invasive robotic surgery

In this paper, a novel concept of surgical forceps integrated with three-axial force sensor is presented. The forceps include two surgical grippers that measure three-axial force, respectively. Using capacitive-type force sensing method, the surgical gripper has the force sensing capability with preserving its original shape and its minimization. And, the force sensor is placed on the distal region of the surgical grippers tip, therefore, it is possible to detect the palpation at backside or edge of the gripper. In this study, the principle of the three-axial force sensing is presented, and the design and realization of the forceps are conducted.

A novel capacitive type torque sensor for robotic applications

This paper presents a novel capacitive type joint torque sensor for robotic applications. The proposed torque sensor enables to measure the rotational torque value while it decouples the external Force/Torque loads without any complicated computing procedure. To measure the joint torque, just two capacitive transducer cells are used. These two cells are located in the opposite sides of each other, which compensates the cross couplings of the torques when external Force/Torque loads are applied. To simply the manufacturing process, the proposed sensor is designed to be composed of three plate-shaped parts and a single printed circuit board (PCB). Lastly, the developed torque sensor is manufactured and its performances are experimentally demonstrated.

Development of surgical forceps integrated with a multi-axial force sensor for minimally invasive robotic surgery

This paper aims to develop novel surgical forceps integrated with a three-axis force sensor for robot-assisted minimally invasive surgery (RMIS). To detect accurate force sensing, a force sensing system is integrated to a gripper of a surgical instrument. At the gripper side, two possible locations are considered, and the sensing system is installed to the distal region of the gripper, which gives major advantages such as the grippers minimization, palpation function, and multi-axis force sensing. Based on the capacitive-type sensing method, the sensor enables the direct measurement of the three-axis force applied to surgical gripper tip. The sensorized gripper is simply designed at a low cost, composed of only four mechanical parts, and, the forceps including two grippers are installed to an instrument that is able to conduct a grasping motion. Therefore, it is used to evaluate the performance of the force sensing system. The sensorized forceps are experimentally validated by using a commercial sensor in an experimental set-up.

A Surgical Palpation Probe With 6-Axis Force/Torque Sensing Capability for Minimally Invasive Surgery

A novel surgical palpation probe installing a miniature 6-axis force/torque (F/T) sensor is presented for robot-assisted minimally invasive surgery. The 6-axis F/T sensor is developed by using the capacitive transduction principle and a novel capacitance sensing method. The sensor consists of only three parts, namely a sensing printed circuit board, a deformable part, and a base part. The simple configuration leads to simpler manufacturing and assembly processes in conjunction with high durability and low weight. In this study, a surgical instrument installed with a surgical palpation probe is implemented. The 6-axis F/T sensing capability of the probe has been experimentally validated by comparing it with a reference 6-axis F/T sensor. Finally, a vivo tissue palpation task is performed in a simulated surgical environment with an animal organ and a relatively hard simulated cancer buried under the surface of the organ.

Design of novel capacitive type torque sensor for robotic applications

This paper introduces a novel capacitive type torque sensor. The developed torque sensor measures single axis torque value by using two capacitance transducing cells. To make a linear relation between the capacitance and the deformation, the shape of flexure hinge is considered to be deformed constantly. Also, the nonlinear curve fitting method is used to fit the capacitance linearly. Finally, the performance of the sensor is verified in reference to a commercial torque sensor.