Narrow Working Space Research Articles

A Neural Network-Based State-Constrained Control Strategy for Underactuated Aerial Transportation Systems Within Narrow Workspace

The aerial transportation system belongs to a symmetrical system and has recently garnered increasing attention from researchers due to its broad application range and convenient operation. The control difficulty of the aerial transportation system lies in the fact that the load is not directly actuated, posing a significant challenge for state-constrained control. Taking the motion of an unmanned aerial vehicle (UAV) suspension transportation system within complex pipelines as an example, this paper employs the the swept volume signed distance field (SVSDF) method to search for state boundaries, which is an aspect not considered or elaborated in many state-constrained control approaches. Furthermore, adaptive state-constrained control based on the radial basis function (RBF) neural network is utilized for the case of experiencing unknown air resistance. The convergence of the proposed method for underactuated and actuated state variables is theoretically demonstrated based on the Lyapunov technique. Compared with existing methods, the error integral index demonstrates that the proposed method displays better convergence capability in the simulation section when considering state constraints under disturbance and air resistance.

PENGARUH MOTIVASI KERJA, LINGKUNGAN KERJA DAN BEBAN KERJA TERHADAP KINERJA KARYAWAN WAROENG SPESIAL SAMBAL (SS) DI YOGYAKARTA

This research is based on the working environment conditions in the Special Sambal (SS) waroeng which has a narrow work space, especially in the kitchen, and the workload requires working quickly but still must pay attention to customer satisfaction at the Special Sambal (SS) waroeng. The aim of this research is to explain the influence of work motivation, work environment and workload on employee performance and to show the variables that most influence the performance of employees at the Special Sambal (SS) waroeng in Yogyakata. This research uses quantitative methods. The sample in this study were employees of the Special Sambal (SS) waroeng in Yogyakata with a total of 100 respondents. The analysis method uses multiple linear regression analysis with the help of the SPSS version 22 program. The results of the research show that work motivation has no effect on employee performance, work environment and workload have an effect on employee performance, and simultaneously work motivation, work environment and workload have an effect on employee performance at Waroeng Spesial Sambal (SS) in Yogyakarta. The research results show that the most dominant variable that influences employee performance is workload.

단일공 다빈치로봇을 이용하여 헤어라인 절개를 통한 일차성 부갑상선 증대증 수술 1예

The da Vinci single port(SP) robotic system features a single arm design that may be particularly suitable for procedures requiring long and narrow working spaces, such as thyroidectomy. Recent advances in preoperative localization studies and the increasing demand for scarless surgery have spurred research into remote surgical techniques for parathyroid surgery. The hairline approach appears to offer the most convenient and safest access to the neck. In this paper, we share our preliminary experience with SP robotic parathyroidectomy, employing only a hairline incision, in one patient with primary hyperparathyroidism. The operation lasted 35 minutes and the console time was 15 minutes. There were no postoperative complications. The SP robot parathyroidectomy using a hairline incision is a viable and safe, providing improved surgical exposure and instrument manipulation.

Design of In-Orbit Sample Container Transfer Mechanism for Chang’E-5 Lunar Sample Return Mission

In this paper, a pawl composite linkage transfer mechanism is designed for the automatic in-orbit sample transfer mission of Chang’E-5 lunar sample return mission, which can realize the sample container in-orbit transfer under various critical constraints such as lightweight, miniaturization, and narrow working space. Resistance during the whole process as well as the sensitive factors that affect the resistance during the sample container transfer process are investigated and designed. The sample container transfer process has been verified by the test system on the ground, indicating that the design can satisfy the requirements of the sample transfer mission. The developed transfer mechanism completed the Chang’E-5 sample return mission successfully with good consistency between space and ground, verifying the correctness and effectiveness of the design.

Development and image-guided control of a robotic endoscope system for nasotracheal intubation

Nasotracheal intubation (NTI) is an advanced airway management technique, in which a flexible endoscope is inserted into the patient’s trachea from the nasal cavity. Due to the hand-eye coordination requirement, the operation of the flexible endoscope in a narrow workspace is a challenge, even for experienced surgeons. In this study, a novel robotic nasotracheal intubation system (RNIS) is proposed to automatically steer the endoscope along the upper respiratory tract. The configuration of the RNIS meets the motion requirement of the flexible endoscope. A lumen center detection method with Kalman filter is designed to determine the position of the lumen center in endoscopic images. Then, a fuzzy logic-based control strategy is developed to enable the RNIS to achieve automatic endoscope steering. Control parameters are updated online using a fuzzy logic algorithm to handle uncertainty. Movements in three degrees of freedom of the endoscope are controlled by the RNIS using visual feedback. Finally, experiments based on a motion simulator and a training mannequin are conducted. Results demonstrate that the proposed RNIS can successfully steer the flexible endoscope along the upper respiratory tract. Automated robotic endoscopes outperform manual operations in terms of operational accuracy.

The Use of Retraction Sutures in End-To-Side Microvascular Anastomosis—A Novel Technical Innovation in Experimental Rat Femoral Model with Successful Use in STA-MCA Bypass in Moyamoya Disease

A narrow working space, small diameters, and the tendency to collapse with clamps make cerebral microvascular anastomosis challenging. A retraction suture (RS) is a novel technique to keep the recipient vessel lumen open during the bypass. To provide a step-by-step overview of RS for end-to-side (ES) microvascular anastomosis on rat femoral vessels and successful use for STA-MCA bypass in Moya Moya disease (MMD) patients. A prospective experimental study with approval from the Institutional Animal Ethics Committee. Femoral vessels ES anastomoses were performed on Sprague Daley rats. The rat model used three types of RS (Adventitial, Luminal, and Flap-retraction sutures). An ES-interrupted anastomosis was done. The rats were observed for an average period of 16.18±5.65 days; the patency was assessed by re-exploration. The immediate patency on the STA-MCA bypasses was confirmed with intra-operative indocyanine green (ICG) angiography and micro-doppler; delayed patency with MRI and DSA after 3-6 months. In the rat model, 45 anastomoses were performed, 15 each using the three subtypes. The immediate patency was 100%. Delayed patency was 42/43 (97.67%), and two rats died during observation. In the clinical series, 59 STA-MCA bypasses were done in 44 patients (average age -18.14±11.09 years) using RS. The follow-up imaging was available for 41/59 patients. Both immediate and delayed patency (41/41 at six months) was 100%. The RS allows continuous visualization of the vessel lumen, reduces the handling of intimal edges, and avoids incorporating the back wall in sutures; thus improving anastomosis patency.

Design and simulation experiment of ridge planting strawberry picking manipulator

Strawberry picking robot arm is an important part of strawberry picking operation. The narrow and complex working environment of ridged strawberry is a great challenge for strawberry picking. Aiming at the problems of narrow working space and complex working environment for strawberry picking in ridge farming, a P-R-R-P-R-R strawberry picking arm is proposed to realize automatic picking of strawberries in ridge farming. By establishing the kinematics model of the strawberry picking manipulator, the Jacobian condition number and operability index of the strawberry picking manipulator are solved to analyze the dexterity of the manipulator. In order to analyze the performance of each joint of the strawberry picking manipulator in the picking operation, a dynamic model of the strawberry picking manipulator was established. The strawberry picking arm has no singular position within the set strawberry picking point range, and the operability indexes are all greater than 0.38. According to the growing environment of strawberry, the simulation route of strawberry picking and the picking operation cycle were set and tested by experiments. Compared with the S-curve motion mode, the motion of each joint of the strawberry picking robotic arm is less smooth in the uniform acceleration-uniform speed-uniform deceleration motion mode. However, the peak velocity of each joint in the uniform acceleration-uniform velocity-uniform deceleration motion mode is lower than that in the S-curve motion mode, Taking three-joint as an example, the peak velocity of S-curve is 19.8° per second, higher than that of the uniform acceleration-uniform speed-uniform deceleration motion mode, which is 16.6° per second. Since joint 4 needs to overcome the influence of gravity, its peak force exceeds 15.5 N. It did not reach the farthest point of its own stroke during the picking process, resulting in a low moment of inertia at the three joints to the end which caused the peak moment of joint 3 to range from 0.2 N·M to 0.31 N·M. The peak torque of joint 5 is all under 0.1 N·M. The total power consumption of the strawberry picking robotic arm is 0.1622 J in a single picking operation using the uniform acceleration-uniform speed-uniform deceleration motion mode. In conclusion, the strawberry picking manipulator designed in this study has good dexterity and can adapt to a ridge environment.

Safety-aware robotic steering of a flexible endoscope for nasotracheal intubation

Automation in robotic endoscopy surgery is an important but challenging research topic. The flexible deformation of the endoscope makes it difficult for surgeons to steer it, especially in a narrow workspace. The safety of endoscope steering has been a major concern in a robotic endoscope. This study presents a safety-aware control framework to enable a robotic endotracheal intubation system (RNIS) to automatically steer the flexible endoscope during nasotracheal intubation (NTI). With the endoscopic image as feedback, we used the fusion of image intensity and optical flow measurements to detect the lumen center. A velocity-based orientation controller is designed to adjust the orientation of the endoscope tip to track the lumen center. To ensure surgical safety, the relative depth from the endoscope tip to the lumen surface is calculated from endoscopic images. With the relative depth as feedback, the feed motion of the endoscope is controlled to prevent the collision between the endoscope tip and its surrounding tissue. The position and orientation of the endoscope tip can be adjusted by the RNIS during NTI. Finally, extensive experiments based on a training manikin were performed. The results indicate that the proposed control framework enables the RNIS to successfully steer the flexible endoscope along the upper respiratory tract with high safety. The performance of lumen center detection is good according to the annotation of experienced users.

A magnetically controlled chemical-mechanical polishing (MC-CMP) approach for fabricating channel-cut silicon crystal optics for the High Energy Photon Source.

Crystal monochromators are indispensable optical components for the majority of beamlines at synchrotron radiation facilities. Channel-cut monochromators are sometimes chosen to filter monochromatic X-ray beams by virtue of their ultrahigh angular stability. Nevertheless, high-accuracy polishing on the inner diffracting surfaces remains challenging, thus hampering their performance in preserving the coherence or wavefront of the photon beam. Herein, a magnetically controlled chemical-mechanical polishing (MC-CMP) approach has been successfully developed for fine polishing of the inner surfaces of channel-cut crystals. This MC-CMP process relieves the constraints of narrow working space dictated by small offset requirements and achieves near-perfect polishing on the surface of the crystals. Using this method, a high-quality surface with roughness of 0.614 nm (root mean square, r.m.s.) is obtained in a channel-cut crystal with 7 mm gap designed for beamlines at the High Energy Photon Source, a fourth-generation synchrotron radiation source under construction. On-line X-ray topography and rocking-curve measurements indicate that the stress residual layer on the crystal surface was removed. Firstly, the measured rocking-curve width is in good agreement with the theoretical value. Secondly, the peak reflectivity is very close to theoretical values. Thirdly, topographic images of the optics after polishing were uniform without any speckle or scratches. Only a nearly 2.5 nm-thick SiO2 layer was observed on the perfect crystalline matrix from high-resolution transmission electron microscopy photographs, indicating that the structure of the bulk material is defect- and dislocation-free. Future development of MC-CMP is promising for fabricating wavefront-preserving and ultra-stable channel-cut monochromators, which are crucial to exploit the merits of fourth-generation synchrotron radiation sources or hard X-ray free-electron lasers.

Endoscopic submucosal dissection using an ultrathin endoscope for superficial pharyngeal cancer: a prospective feasibility study (with video).

Background and study aims Endoscopic submucosal dissection (ESD) of pharyngeal cancers with conventional endoscopes often is difficult, not only because of the narrow working space, but also because endoscope maneuverability in the pharynx is poor due to interference from the endotracheal tube and/or hyoid bone. However, we hypothesized that those problems could possibly be resolved by use of an ultrathin endoscope for ESD of superficial pharyngeal cancer. The aim of this prospective interventional study was to investigate the feasibility of ESD for superficial pharyngeal cancer using an ultrathin endoscope. Patients and methods This feasibility study was conducted at NTT Medical Center Tokyo between June 2020 and September 2021, and data from a total of 20 consecutively superficial pharyngeal cancers were analyzed. The primary outcome measure was the R0 resection rate. The ESD completion rate, en bloc resection rate, procedure time, and frequency of intraoperative and postoperative adverse events (AEs) were also evaluated as secondary outcome measures. Results Data from 16 patients with 20 lesions were included in the analysis. All of the lesions were successfully resected by ultrathin endoscope ESD, and the en bloc and R0 resection rates were 100 % and 85.0 % (17/20), respectively; the procedure time was 37.8 ± 28.2 minutes. No intraoperative or postoperative AEs were encountered in any cases. Conclusions ESD using an ultrathin endoscope is feasible for superficial pharyngeal cancers and has potential to be a safe and effective treatment option for these cancers.

Our initial single port robotic cholecystectomy experience: A feasible and safe option for benign gallbladder diseases.

Although single-port laparoscopic cholecystectomy has been performed for over 25 years, it is still not popular. The narrow working space used in this surgery limits the movement of instruments and causes ergonomic challenges. Robotic surgery not only resolves the ergonomic challenges of single-port laparoscopic surgery but is also considered a good option with its additional technical advantages, like a three-dimensional display and not being affected by tremors. However, the extent to which these technical and ergonomic advantages positively affect the surgical outcomes and how safe the single-port robotic surgeries need to be assessed for each particular surgery. To evaluate the feasibility and safety of single-port robotic cholecystectomy for patients with cholelithiasis. The electronic records of the first 40 consecutive patients with gallbladder lithiasis who underwent single-port robotic cholecystectomy from 2013 to 2021 were analyzed retrospectively. In addition to the demographic characteristics of the patients, we analyzed American Society of Anesthesiologists (ASA) scores and body mass index. The presence of an accompanying umbilical hernia was also noted. The amount of blood loss during the operation, the necessity to place a drain in the subhepatic area, and the need to use grafts during the closure of the fascia of the port site were determined. Hospital stay, readmission rates, perioperative and postoperative complications, the Clavien-Dindo complication scores and postoperative analgesia requirements were also evaluated. The mean age of the 40 patients included in the study was 49.5 ± 11.6 years, and 26 were female (65.0%). The umbilical hernia was present in 24 (60.0%) patients, with a body mass index median of 29.3 kg/m2 and a mean of 29.7 ± 5.2 kg/m2. Fifteen (37.5%) of the patients were evaluated as ASA I, 18 (45.0%) as ASA II, and 7 (17.5%) as ASA III. The mean bleeding amount during the operation was 58.4 ± 55.8 mL, and drain placement was required in 12 patients (30.0%). After port removal, graft reinforcement during fascia closure was preferred in 14 patients (35.0%). The median operation time was 93.5 min and the mean was 101.2 ± 27.0 min. The mean hospital stay was 1.4 ± 0.6 d, and 1 patient was readmitted to the hospital due to pain (2.5%). Clavien-Dindo I complications were seen in 14 patients (35.0%), and five (12.5%) complications were wound site problems. In addition to the technological and ergonomic advantages robotic surgery provides surgeons, our study strongly supports that single-port robotic cholecystectomy is a feasible and safe option for treating patients with gallstones.

An overview of lumbar anatomy with an emphasis on unilateral biportal endoscopic techniques: A review

Unilateral biportal endoscopy (UBE) is a major surgical technique used to treat degenerative lumbar diseases. The UBE technique has the advantages of flexible operation, high efficiency, and a large observation and operation space. However, as a typical representative of minimally invasive techniques, UBE still needs to complete a wide range of decompression and tissue resection in a narrow working space, resulting in many surgery-associated injuries. Therefore, it is necessary to reduce complications by familiarity with the anatomy of the lumbar spine. Based on the UBE technique, this review article provides historical and current information on the anatomical structures of the lumbar vertebrae, such as the articular process, pedicle, lamina, ligamentum flavum, nerve root, intervertebral disc, and artery supply.

A novel approach for nature gas hydrate separation: Downhole spiral-cyclone coupled hydraulic in-situ separation

The weakly cemented mixture slurry which is formed by the natural gas hydrate (NGH) solid-state fluidization mining method that is composed of natural gas hydrate, sediment and water. The downhole cyclone of NGH needs to deal with such problems as high viscosity, narrow radial working space, and difficult to adjust the split ratio. Directly using the conventional solid-liquid cyclone structure for downhole sand removal cannot obtain good separation performance. And the conventional separator does not have a tubular structure suitable for solid fluidization exploitation of NGH. Therefore, in order to solve the problem of weak cementation between NGH and sediment due to large sand production during NGH exploitation, this study proposes a new method to separate weakly cemented natural gas hydrate based on the principle of spiral-cyclone coupling. And the model of spiral-cyclone separator was established. This method can break weakly cemented solid-phase particles in the slurry, and the effective separation and removal of ultra-fine sediment with cross-scale and micron size. The research also designs and optimizes the separation device for NGH sand removal. According to numerical simulation and theoretical analysis, the separation efficiency is greater than 60% when the particle size is larger than 5 µm and the inlet velocity is between 2 m/s and 10 m/s. The research results show that the proposed spiral-cyclone separation method has the characteristics of high separation efficiency, strong sand removal, and can break the cementation bond between the sediment and natural gas hydrate, which is a high-efficiency solid-liquid separation technology.

Development and Application of Dual-Polarization Antenna for Dielectric Logging Sensor.

Because the dielectric constant of water is greater than that of oil and gas, dielectric logging sensors can effectively distinguish oil and gas reservoirs from water layers by measuring the dielectric parameters of formations. Under the special working conditions during the logging of boreholes drilled for oil and gas exploration, such as high temperature and pressure and a narrow working space, the endurance and effectiveness of the antenna in the dielectric logging sensor are crucial. This paper presents a design method for a dual-polarization slot antenna for such working conditions. We theoretically analyzed the working principle of this antenna, established the antenna model, and evaluated its radiation characteristics through simulation. Subsequently, we developed and tested the proposed antenna. The antenna could withstand a high temperature and pressure of 175 °C and 140 MPa, respectively. A dielectric logging sensor using the proposed antenna was successfully applied in oilfield logging.

Single-Fingered Reconfigurable Robotic Gripper With a Folding Mechanism for Narrow Working Spaces

This letter proposes a novel single-fingered reconfigurable robotic gripper for grasping objects in narrow working spaces. The finger of the developed gripper realizes two configurations, namely, the insertion and grasping modes, using only a single motor. In the insertion mode, the finger assumes a thin shape such that it can insert its tip into a narrow space. The grasping mode of the finger is activated through a folding mechanism. Mode switching can be achieved in two ways: switching the mode actively by a motor, or combining passive rotation of the fingertip through contact with the support surface and active motorized construction of the claw. The latter approach is effective when it is unclear how much finger insertion is required for a specific task. The structure provides a simple control scheme. The performance of the proposed robotic gripper design and control methodology was experimentally evaluated. The minimum width of the insertion space required to grasp an object is 4 mm (1 mm, when using a strategy).

Incrementally Stochastic and Accelerated Gradient Information Mixed Optimization for Manipulator Motion Planning

This paper introduces a novel motion planner, incrementally stochastic and accelerated gradient information mixed optimization (iSAGO), for robotic manipulators in a narrow workspace. Primarily, we propose the overall scheme of iSAGO informed by the mixed momenta for an efficient constrained optimization based on the penalty method. In the stochastic part, we generate the adaptive stochastic momenta via the random selection of sub-functionals based on the adaptive momentum (Adam) method to solve the body-obstacle stuck case. Due to the slow convergence of the stochastic part, we integrate the accelerated gradient descent (AGD) to improve the planning efficiency. Moreover, we adopt the Bayesian tree inference (BTI) to transform the whole trajectory optimization (SAGO) into an incremental sub-trajectory optimization (iSAGO), which improves the computation efficiency and success rate further. Finally, we tune the key parameters and benchmark iSAGO against the other 5 planners on LBR-iiwa on a bookshelf and AUBO-i5 on a storage shelf. The result shows the highest success rate and moderate solving efficiency of iSAGO.

Multifunctional Parallel Gripper With Three Actuators

This article proposes a parallel gripper with a rack and pinion mechanism that is more versatile than the traditional parallel grippers with three actuators. The proposed gripper can switch between large and small fingers via lengthening and shortening actions, which improves its ability to pick up objects with various sizes and weights, as well as in narrow workspaces. This function also enables the gripper to perform three-face grasping, wherein three faces of a grasped object are securely in contact with the gripper, thereby improving the robustness of grasping. The gripper can also perform in-hand manipulations using a stand. We analyze the grasping force of the three-face grasp and show that it is more robust against external forces that generate the moment about the normal of the finger surface than the traditional two-face grasp. Finally, we demonstrate the improved abilities of the developed gripper and the robustness of the three-face grasp through the experimental results. The possible applications of this gripper include tasks in which the sizes, weights, and arrangements of the objects are not optimized for robot hands.

Systematic design of snake arm maintainer in nuclear industry

This paper develops a remote handling system with a Snake Arm Maintainer (SAM) as the end effector, which aims to meet the maintenance needs of various narrow working spaces of the Chinese Fusion Engineering Test Reactor (CFETR). The multi-joint snake-arm is designed with the principle of layered drive to realie the angle synchronisation of adjacent joints, which reduces the complexity of the drive control system, and reduces the volume and weight while ensuring a high spatial curvature. The drive box is connected to the Multi-Purpose Overload Robot (CMOR) through a quick-change connector. The worm gear mechanism realies the reverse folding of the SAM and close to the CMOR, enabling access to the narrow vacuum chamber. Two working methods of SAM are designed based on trajectory planning and trajectory tracking. Finally, based on the actual environment of the CFETR vacuum chamber, simulation experiments were carried out on the rationality of the structural design of the SAM and the correctness of the working methods, which verified the feasibility of working in a narrow vacuum chamber.

Colonic endoscopic submucosal dissection using a novel robotic system.

111 Background: Appropriate tissue tension and clear visibility of the dissection area using traction are essential for effective and safe endoscopic submucosal dissection (ESD). We developed a robotic assistive traction device for colonoscopy.This is a preclinical animal study to evaluate the performance of colorectal ESD using novel robotic system. Methods: Experienced endoscopist performed ESD on ex vivo porcine colon ten times using a robot and ten times by the conventional method. The outcome measures were operating time (from starting incision to finishing dissection), completeness of resection, procedure-related adverse events, and limitations of arm manipulation in a narrow working space as assessed by counting the frequency of blind cutting.We also conducted an in vivo feasibility study on live pig. Results: Total of twenty colonic lesions were resected from ex vivo porcine colon. The submucosal dissection speed was significantly faster in robotic ESD than in conventional ESD (P = 0.002). Adverse events such as perforation were also significantly higher in the conventional group. In the in vivo feasibility study, robot was attached to the colonoscope and inserted into the proximal colon. ESD was performed successfully. Conclusions: When the robot was assisting in the ESD procedure, the dissection speed improved significantly. Our robotic device can thus provide simple, effective, and safe multidirectional traction during colonic ESD.

Uniportal thoracoscopic decortication: start away from empyema approach

Aim: Video-assisted thoracoscopic surgery (VATS) is now a gold standard in treating early-stage empyema, while much debate still exists considering the effectiveness of this approach for late-stage empyema. Most concerns arise from the crowded rib cage, narrow working space, and ability to free trapped lungs quickly, mainly if uniportal VATS is used. However, unlike uniportal VATS lobectomy, there is no consensus about standard steps for uniportal VATS decortication to ensure smooth and effective surgery. We try to offer standard, easy-to-replicate steps for this approach to evaluate the efficacy and safety of the “start away from empyema” approach for uniportal VATS decortication in the management of stage II and III empyema. Methods: A prospective case series study has been conducted on 25 patients. All patients with stage II and III empyema were admitted to the Cardiothoracic Surgery Department between October 2017 and March 2020. VATS procedure was done under general anesthesia by a double-lumen tube for selective ventilation. Demographic data, preoperative diagnosis, intraoperative findings, hospital stay, and complications were recorded. Results: Twenty-five patients were enrolled in this study with a median age of 35 years. The duration of illness ranged between 14 and 60 days, with a median (IQR) of 25 (17) days. In (88%) of the patients, there was a successful outcome defined as a near-complete resolution on Chest X-ray (scoring of 3 or 4) and chest US (scoring of 2 or 3). Only three (12%) patients had a partially successful outcome. All patients with partial success suffered from infection associated with malignant effusion. Conclusion: “Start away from empyema” approach for uniportal VATS decortication in stage II and III empyema could be safe and effective in treating loculated nonmalignant pleural effusion.