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Efficacy of robot arm-assisted endoscopic submucosal dissection in live porcine stomach (with video)

Sun, 30 Jun 2024 15:00:00 GMT

Title: Efficacy of robot arm-assisted endoscopic submucosal dissection in live porcine stomach (with video) Author(s): Kim, Joonhwan; Lee, Dong-Ho; Kwon, Dong-Soo; Park, Ki Cheol; Sul, Hae Joung; Hwang, Minho; Lee, Seung-Woo Abstract: Endoscopic submucosal dissection (ESD) is technically challenging and requires a high level of skill. However, there is no effective method of exposing the submucosal plane during dissection. In this study, the efficacy of robot arm-assisted tissue traction for gastric ESD was evaluated using an in vivo porcine model. The stomach of each pig was divided into eight locations. In the conventional ESD (C-ESD) group, one ESD was performed at each location (N = 8). In the robot arm-assisted ESD (R-ESD) group, two ESDs were performed at each location (N = 16). The primary endpoint was the submucosal dissection speed (mm2/s). The robot arm could apply tissue traction in the desired direction and successfully expose the submucosal plane during submucosal dissection in all lesion locations. The submucosal dissection speed was significantly faster in the R-ESD group than in the C-ESD group (p = 0.005). The blind dissection rate was significantly lower in the R-ESD group (P = 0.000). The robotic arm-assisted traction in ESD enabled a significant improvement in submucosal dissection speed, blind dissection rate which suggests the potential for making ESD easier and enhancing procedural efficiency and safety. © The Author(s) 2024.

SAM: Semi-Active Mechanism for Extensible Continuum Manipulator and Real-Time Hysteresis Compensation Control Algorithm

Sat, 30 Nov 2024 15:00:00 GMT

Title: SAM: Semi-Active Mechanism for Extensible Continuum Manipulator and Real-Time Hysteresis Compensation Control Algorithm Author(s): Park, Junhyun; Jang, Seonghyeok; Park, Myeongbo; Park, Hyojae; Yoon, Jeonghyeon; Hwang, Minho Abstract: Background: Cable-driven continuum manipulators (CDCMs) enable scar-free procedures but face limitations in workspace and control accuracy due to hysteresis. Methods: We introduce an extensible CDCM with a semi-active mechanism (SAM) and develop a real-time hysteresis compensation control algorithm using a temporal convolution network (TCN) based on data collected from fiducial markers and RGBD sensing. Results: Performance validation shows the proposed controller significantly reduces hysteresis by up to 69.5% in random trajectory tracking test and approximately 26% in the box pointing task. Conclusion: The SAM mechanism enables access to various lesions without damaging surrounding tissues. The proposed controller with TCN-based compensation effectively predicts hysteresis behaviour and minimises position and joint angle errors in real-time, which has the potential to enhance surgical task performance. © 2024 John Wiley & Sons Ltd.

Hysteresis Compensation of Flexible Continuum Manipulator using RGBD Sensing and Temporal Convolutional Network

Sun, 30 Jun 2024 15:00:00 GMT

Title: Hysteresis Compensation of Flexible Continuum Manipulator using RGBD Sensing and Temporal Convolutional Network Author(s): Park, Junhyun; Jang, Seonghyeok; Park, Hyojae; Bae, Seongjun; Hwang, Minho Abstract: Flexible continuum manipulators are valued for minimally invasive surgery, offering access to confined spaces through nonlinear paths. However, cable-driven manipulators face control difficulties due to hysteresis from cabling effects such as friction, elongation, and coupling. These effects are difficult to model due to nonlinearity and the difficulties become even more evident when dealing with long and coupled, multi-segmented manipulator. This paper proposes a data-driven approach based on Deep Neural Networks (DNN) to capture these nonlinear and previous states-dependent characteristics of cable actuation. We collect physical joint configurations according to command joint configurations using RGBD sensing and 7 fiducial markers to model the hysteresis of the proposed manipulator. Result on a study comparing the estimation performance of four DNN models show that the Temporal Convolution Network (TCN) demonstrates the highest predictive capability. Leveraging trained TCNs, we build a control algorithm to compensate for hysteresis. Tracking tests in task space using unseen trajectories show that the proposed control algorithm reduces the average position and orientation error by 61.39% (from

$\mathbf {13.7mm}$

$\mathbf {5.29 mm}$

) and 64.04% (from 31.17

$^{\circ }$

to 11.21

$^{\circ }$

), respectively. This result implies that the proposed calibrated controller effectively reaches the desired configurations by estimating the hysteresis of the manipulator. Applying this method in real surgical scenarios has the potential to enhance control precision and improve surgical performance. IEEE

Asymmetric Rolling Contact Joint for Enhanced Payload Capabilities

Wed, 31 Jan 2024 15:00:00 GMT

Title: Asymmetric Rolling Contact Joint for Enhanced Payload Capabilities Author(s): Ahn, Jeongdo; Hwang, Minho; Kong, Dukyoo; Kim, Joonhwan; Kwon, Dong-Soo Abstract: It is challenging for a surgical joint to tolerate a sufficient payload when downsizing its diameter. The tradeoff between payload and diameter is even more evident when designing robots with strict size constraints, such as in flexible endoscopic surgery applications. To address this issue, we propose a novel asymmetric rolling contact (ARC) joint that has two different rolling radii with a wire hole slit that is actuated by a tendon-driven mechanism. The ARC joint is designed to tolerate a high payload in the dominant direction, such as when lifting tissue or pulling a suture thread. We analyzed the effects of various design variables on the payload capability of the ARC joint. The results of the payload experiment suggest that the designed ARC joint has a maximum payload of 2.6 N with a 3.4 mm diameter, which enhances the payload by 71.9% compared to the conventional symmetric rolling joint. We confirmed that the endoscopic surgical task may be feasibly conducted using the proposed joint for two major tasks: endoscopic submucosal dissection and surgical suturing. © 2024 IEEE