Endoscopic submucosal dissection (ESD) is a procedure targeted for early gastrointestinal cancer. Traction plays a crucial role in enhancing the efficiency of cutting lesions, thereby reducing procedural complexity and duration. From the perspective of traction devices, current non-magnetic ones hold shortcomings in complicating the workspace in directional tissue manipulation; Current magnetic traction devices cannot be prepared before the procedure, and require the withdrawal of endoscope in the midway to re-introduce the magnetic retractor to the lesion site. Towards these plights, this paper introduces a robotic flexible magnetic retractor designed for tissue manipulation during ESD. Precisely, the flexible prototype can be seamlessly inserted through the instrument channel of an endoscope to the lesion site without the need for endoscope withdrawal. Moreover, the introduction of robotic magnetic actuation enhances the agile control of magnetic retractors while alleviating the surgeon's workload in magnetic-retractor-assisted ESD. The experimental results validate the functionality and efficacy of the prototype magnetic retractor in magnetic traction-assisted ESD procedures. The retractor demonstrated its ability to provide adequate traction and accomplish clinical tasks. This innovative approach holds promise for enhancing the efficiency and outcomes of ESD procedures, offering a compelling alternative to traditional traction methods.

Manual rigid endoscopes have defects such as a low efficiency, difficult operation, and safety risks, and the antinoise interference ability, convergence speed, and control accuracy of the neural network control technology for the existing autonomous endoscopes are often ignored. Solving these problems is important for the stable operation of endoscopes. Therefore, a new adaptive fast convergent antinoise dual neural network (AFA-DNN) controller for the visual servo control of ten-degree of freedom flexible endoscope robots (FERs) with physical constraints is proposed in this work. First, the control scheme of the FERs is formulated as a quadratic programming problem, and then, an AFA-DNN visual servo controller is designed for the FERs. The adaptive gains of the controller can accelerate the convergence, improve the antinoise ability, and increase the convergence accuracy of the controller. Then, according to the Lyapunov theory, the fast convergence of the AFA-DNN in finite time is proven for both noise-free and noisy conditions. The experimental results indicate that the FER controlled by the proposed AFA-DNN can accurately track various trajectories and that the AFA-DNN has a better antinoise interference ability, higher convergence accuracy, and faster convergence speed than conventional methods. The convergence speed of the AFA-DNN is increased by a factor of 4.22 by using the adaptive gains. Experiments also indicate that the AFA-DNN remains well functioning under various noise disturbances (such as constant, periodic, linear, and Gaussian noise).

This paper is concerned with the issue of the kinematic model-based bending control for the magnetically actuated robotic endoscope and its application for automatic retroflexion. By the utilization of the Cosserat rod theory and the transformation in the magnetic tip of the endoscope, the comprehensive kinematic model of the magnetically-actuated robotic endoscope is established. Afterward, a magnetic control scheme for the bending motion is proposed by co-developing an error feedback PID control strategy and the model-based feedback approach. Moreover, as one unique kind of bending motion, retroflexion is taken into account, and the strategy aimed at the bid of compact space retroflexion is presented by virtue of the introduction of serial waypoints pursuing the position of the magnetic tip being close to the midline as possible. Eventually, the developed modeling and bending control scheme and the compact space retroflexion strategy are examined in a magnetically actuated robotic endoscope system to manifest the effectiveness and applicability of the theoretical approach. The experimental results indicate that the designed controller can drive the endoscope to bend to the desired pose and show a reduction of about 47.01% in the sweeping area and 79.25% in the last distance to midline achieved by conducting compact space retroflexion in comparison to “U” type one.

Characteristics of wireless manipulation based on permanent magnet coupling, including anchoring distance, panning torque, and translational force, are assessed in this paper. The study focuses on a typical scenario where a slave robot embedded with a small permanent magnet can be remotely controlled within a constrained area by a master large permanent magnet placed outside the environment at a certain distance from it. The key parameters (force and torque) acting on the slave robot are quantified and evaluated. In this article, several combinations of permanent magnets with various dimensions and configurations are studied using finite element methods. Based on the obtained results, we create a lookup table for each parameter, serving as a guideline to help interested researchers choose suitable magnetic combinations for their applications.

To solve the problems of discomfort and potential colon perforations of patients that arise when standard colonoscopes are used for colonoscopy, an electromagnetically actuated soft-tethered colonoscope robot (EASCR) is here introduced. Owing to EASCRs’ highly nonlinear and complex application environments, the hybrid vision/magnetic-force tracking control for these types of robots remains a challenging research issue, and the lack of current constraints may also give rise to safety concerns. Therefore, a hybrid vision/magnetic-force fast convergent dual neural network (DNN) tracking controller for an EASCR with current constraints is developed to alleviate patient discomfort and ensure the safe and smooth progression of colonoscopy. First, EASCR motion/vision and electromagnetically actuated force nonlinear coupling models are established, and a quadratic programming visual servo-tracking control scheme with current constraints is designed. Second, a novel DNN solver for the nonlinear control scheme is developed, and its convergence in finite time is strictly proved. The results of simulations and experiments indicate that the designed control method can well control EASCRs with current constraints to achieve tracking tasks, and it has a stronger anti-disturbance ability, faster convergence, and higher convergence accuracy than existing methods.

This paper presents a long-range magnetic actuated and guided endoscope for uniport video-assisted thoracic surgery (VATS). In VATS, the incision is quite narrow and part of the chest wall may be very thick. So, the magnetic endoscope system is required to produce sufficient attractive force at a considerable distance with a compact dimension. In this paper, a magnetic endoscope system is developed to meet the aforementioned clinical demands. In the system, both the internal and external units consist of two cylindrical magnets at both ends and a semi-cylindrical magnet in the middle. Coupled with the magnetic field from the external unit, the internal endoscope can achieve anchoring, tilting, panning, and translating to provide the desired view for the surgeon. The rotation of the endoscope is dynamically modeled by combining magnetic theory and coordinate transformation. The prototype is made with a boundary box of 10×14×56 mm, which can be inserted through the narrow incision in VATS. In the experiment, the developed models of anchoring, tilting, and panning were verified. The magnet configuration in the system can achieve a static anchoring distance of 95 mm and exhibits enhancement in attractive force compared with other designs.