Narrow Working Space Research Articles

Robotics in laryngeal surgery

While transoral laser microsurgery has been the gold standard for laryngeal surgery for many years, recently transoral robotic surgery (TORS) has become a new treatment option not being restricted to a straight line of view which can be an obstacle during resection. In combination with specifically designed retractors TORS can provide a superior visualization and allows tissue manipulation especially in the narrow working space of the larynx. The present article describes the commercially available robotic systems suitable for transoral surgery in adult benign laryngeal masses and highlights on the use of TORS retractors. Additionally, the most relevant benign laryngeal masses in adults will be addressed with special emphasis on transoral robotic accessibility, visualization, and surgical resection techniques. Additionally, using the Medrobotics system TORS was evaluated for surgery of benign laryngeal masses in 37 adults suffering from cysts, polpys, papillomas, dysplasias, and leukoplakias: Excellent visualization, surgical access to all lesions and complete resection without any severe side effects could be achieved. In conclusion, TORS can be a valuable tool in surgery for adult benign laryngeal masses. While transoral laser microsurgery has been the gold standard for laryngeal surgery for many years, recently transoral robotic surgery (TORS) has become a new treatment option not being restricted to a straight line of view which can be an obstacle during resection. In combination with specifically designed retractors TORS can provide a superior visualization and allows tissue manipulation especially in the narrow working space of the larynx. The present article describes the commercially available robotic systems suitable for transoral surgery in adult benign laryngeal masses and highlights on the use of TORS retractors. Additionally, the most relevant benign laryngeal masses in adults will be addressed with special emphasis on transoral robotic accessibility, visualization, and surgical resection techniques. Additionally, using the Medrobotics system TORS was evaluated for surgery of benign laryngeal masses in 37 adults suffering from cysts, polpys, papillomas, dysplasias, and leukoplakias: Excellent visualization, surgical access to all lesions and complete resection without any severe side effects could be achieved. In conclusion, TORS can be a valuable tool in surgery for adult benign laryngeal masses.

A case study on the plan for soil reinforcement by TCS in south korea

Compaction grouting was developed in the 1950s as a remedial measure for the correction of building settlement, and used almost exclusively for that purpose for many years. Over the past 25 years, however, compaction grouting technology has evolved to treat a wide range of subsurface conditions for new and remedial construction. Compaction grouting is used foundation rehabilitation, ground improvement, railroad subgrade stabilization, seismic/liquefaction mitigation, sinkhole remediation, tunneling stabilization, void filling. It also has merit that makes possible to construct structures having narrow working spaces. But the effects of ground improvement depending on the type of soil must be studied in order to adopt in various soil(granular soil and cohesive soil). In this paper, field and laboratory tests were performed to understand effects of ground improvement for soft ground and seismic mitigation. To know the characteristics of bearing capacity in adjacent ground, plate loading test for behind the improving ground. Strength characteristics of TCS were indicated by uniaxial compression test. Ground improvement effect by TCS together strength increment effect by TCS itself was proved that TCS can be used for soil improvement method using bearing capacity increment.

The First Human Trial of Transoral Robotic Surgery Using a Single-Port Robotic System in the Treatment of Laryngo-Pharyngeal Cancer.

This study aimed to evaluate the feasibility and safety of the DaVinci SP system for performing transoral robotic surgery (TORS) in patients with head and neck cancer. From October 2018 to April 2019, the medical records of 41 patients who underwent TORS using the DaVinci SP system were retrospectively reviewed. During TORS, three robotic arms could be used to perform a geometric resection of the lesion in a narrow working space. The mean total operation time was 60min, and the average time required to set up the robotic system was 10min or less. All patients successfully underwent TORS. All robotic arms were inserted through a single port, which widened the working space around the patient's head and allowed the operative assistant an easy approach to the patient during the operation. The joggle joint of the robotic arms aided easy manipulation within the confined working space. The joggle joints of the endoscopic arm were controlled through the navigation system, which was very helpful in securing superior visualization of the surgical site, especially in the area of the larynx and the hypopharynx. The study confirmed that the DaVinci SP system provided technical advantages above the Si and Xi systems for performing TORS. It was especially helpful in ensuring proper visualization of the surgical field and in performing precise surgery during surgery to the tongue base or the hypopharyngeal lesion.

The cheek expander enables tonsillectomy with a wide view and working space

ObjectiveTonsillectomy is the most commonly performed otolaryngological surgeries.Although a surgical method had been established, obtaining a clear surgical field still remains problematic, and injury to the corners of the mouth may occur. For safer tonsillectomy, we use a cheek expander coupled with a Davis mouth gag. The devise retract both corners of the mouth to a wide lateral position. We report here our investigation in the application of a cheek retractor for tonsillectomy and also report the advantages of this device. MethodsA series of 13 tonsillectomies (7 adults and 6 children) using the cheek retractor from November 2017 to March 2018 were enrolled for this study. The cheek retractor was applied after the Davis mouth-opening device was in place. We measured the oral angle diameter before and after placement of the cheek retractor. ResultsThis devise increases the width of the visual field 1.6 times and provides a good surgical field. In addition, this device covers the mouth fully and safely, so no lip injury develops ConclusionThe cheek retractor is useful for improving the narrow working space in tonsillectomy.

Robotic-assisted minimally invasive esophagectomy versus the conventional minimally invasive one: A meta-analysis and systematic review.

Conventional video-assisted minimally invasive esophagectomy (MIE) is safe and associated with low rates of morbidity and mortality, but the two-dimensional monitor reduces eye-hand harmony and viewing yield. Robotic-assisted minimally invasive esophagectomy (RAMIE) with its virtual reality simulators offers a realistic three-dimensional environment that facilitates dissection in the narrow working space, but it is expensive and requires longer operative time. Therefore, the aim of this meta-analysis was to assess the safety and feasibility of RAMIE versus MIE in patients with esophageal cancer. PubMed, EMBASE, Cochrane library, and Chinese Biomedical Literature databases were systematically searched up to 21 September 2018 for case-controlled studies that compared RAMIE with MIE. Eight case-controlled studies involving 1862 patients (931 under RAMIE and 931 under MIE) were considered. No statistically significant difference between the two techniques was observed regarding R0 resection rate (OR=1.1174, P=0.8647), conversion to open (OR=0.7095, P=0.7519), 30-day mortality rate (OR=0.8341, P=0.7696), 90-day mortality rate (OR=0.3224, P=0.3329), in-hospital mortality rate (OR=0.3733, P=0.3895), postoperative complications, number of harvested lymph nodes (mean difference [MD]=0.8216, P=0.2039), operation time (MD=24.3655min, P=0.2402), and length of stay in hospitals (LOS) (MD=-5.0228day, P=0.1342). The meta-analysis showed that RAMIE was associated with a significantly fewer estimated blood loss (EBL) (MD=-33.2268mL, P=0.0075). And the vocal cord palsy rate was higher in the MIE group compared with RAMIE, and the difference was significant (OR=0.5696, P=0.0447). This meta-analysis indicated that RAMIE and MIE display similar feasibility and safety when used in esophagectomy. However, randomized controlled studies with larger sample sizes are needed to evaluate the benefit and harm in patients with esophageal cancer undergoing RAMIE.

Mechanism Design of Electric Robot of Distribution Network for Cut Off or Connection of Leading Wire

As a typical distribution network live working project, the live disconnecting and connecting lead wires are frequently carried out in live working, and the working environment has the characteristics of unstructured and narrow working space. By comprehensively considering the working environment and work tasks of the live working robots in the distribution network, a distribution networked electric disconnecting and connecting streamline robot based on the adjustable crawler-type mobile platform is constructed. The adjustable crawler belt type mobile platform is designed to enhance the application range of the working robot. A six-degree-of-freedom multi-manipulator cooperative working mechanism system is proposed to design a high-performance live working end to realize the insulation wire stripping, clamping, nut tightening, loosen and other functions. The results show that the proposed power distribution disconnected and connected streamline robot can effectively replace the manual task and improve the intelligent level of the distribution network maintenance system.

Path rendering and velocity restriction with welding-assisting device composed of magnetorheological brakes

Abstract In the shipbuilding industry, welding is one of the forms of nonautomated heavy labor, and the welding operator is required to weld indeterminate objects in a narrow working space. Therefore, it is difficult to use large equipment, such as industrial robots. In addition, it is not easy to perform high-quality welding, because tracing a welding line accurately at a constant speed requires a long training period. In this research, the aim was to develop a welding assist device that can be applied to a welding environment. The proposed device fixes to the welding surface by magnetic force and assists semiautomatic welding with a magnetorheological (MR) brake. MR brakes have a sufficient response speed compared with powder brakes, have a large output weight ratio, and are considered to be suitable for welding assistance. In this work, a strategy for control of path rendering and speed restriction by MR brakes is proposed. Its effectiveness was confirmed by experiments with a prototype.

A wide dynamic range and high resolution all-fiber-optic turbidity measurement system based on single photon detection technique

A high-resolution fiber-optic detection system has been developed to measure the wide dynamic range of turbidity. To obtain high-resolution measurement results, a high sensitive single photon detection technique (SPDT) has been used in the system. Based on fiber characteristics, a compact probe structure for fiber-optic integrated transceiver (FITP) is designed to transmitting and collection light signal, which has the capability of detecting turbidity in the narrow workspace. By combining the Beer-Lambert (B-L) law transmission law with single photon counting theory, a novel turbidity measurement theoretical model has been proposed, which shows a good exponential relationship over the whole measurement range from 0.01 to 1000 NTU (Nephelometric Turbidity Units). However, when detecting 0.01–0.1 NTU low turbidity, the experimental results turn into an approximate linear relationship, which good agrees with the proposed theoretical model. Last, some issues about the optimization of light intensity and requiring attention on constructing a practical distributed multi-point water turbidity remote monitoring system in the outdoors are also discussed. It was found that the system can achieve a measurement dynamic range as wide as 50 dB with a resolution better than 0.01 NTU in the range of 0.01–1000 NTU, which is suitable for some specific turbidity measurement in remote and narrow workspace.

Development of an observational checklist for falling risk assessment of high-voltage transmission tower construction workers

Falls from elevation have been reported to cause the highest number of fatalities in the Taiwan construction industry, accounting for 43.53% of all construction worker fatalities for the period from 2006 to 2015, inclusive. High-voltage transmission tower construction is a high-risk operation due to the construction site locations, extreme climatic factors, elevated working surfaces, and narrow working space. However, the factors contributing to the risk of falls in high-voltage transmission tower construction work have not been characterized. This paper describes the development and application of an observational checklist for assessing exposure to fall risks. Three contributing factors, movement, stability, and fall protection measures, were characterized based on the suggestions of ergonomic experts, interviews of supervisors and workers, and on-site observations. Inter-observer reliability test results showed that inter-observer reliability of the observational checklist was acceptable to excellent. A pilot study assessing five primary construction operations suggested that position shifting, wherein workers were found to have frequent exposure to the whole-body movement level and spent the least time in a tied-off full body harness, was the operation with the highest fall risk. These results demonstrated that the observational checklist can be used to identify specific construction operations with fall hazards.

Translaminar Approach for Treatment of Hidden Zone Foraminal Lumbar Disc Herniations: Surgical Technique and Preoperative Selection of Patients with Long-Term Follow-Up

Lumbar disc herniation is a common degenerative disease of the lumbar spine with a prevalence of 1%-3% in some population studies. In 10% of patients, there is a fragment migrated cranially in Macnab's "hidden zone." In selected cases, this fragment can be removed with a translaminar approach that was described in 1998. We provide a detailed description of the technical advantages and pitfalls of the translaminar approach in a consecutive series of 32 patients treated at our institution. Patients were divided preoperatively and postoperatively into 5 classes based on the Oswestry Disability Index (ODI): class 1, ODI 0%-20% (minimal disability); class 2, 20%-40% (moderate disability); class 3, 40%-60% (severe disability); 60%-80% (crippled); 80%-100% (bedridden or disabling symptoms). Four (12.5%) patients were upgraded 1 ODI class after the operation; 6 (18.7%) patients were upgraded 2 classes, 8 (25%) patients were upgraded 3 classes, and 11 (34.4%) patients were upgraded 4 classes. In 3 (9.4%) patients, ODI class did not change after the operation. After surgery, 7 (21.9%) patients developed mild low back pain. Mean follow-up was 25 months. When performed by dedicated spinal neurosurgeons, the translaminar approach is safe and effective in patients with long-term follow-up. Most patients showed an improvement in ODI. Major pitfalls were related to surgical selection and the narrow working space.

A target localization method with monocular hand-eye vision

The installation of binocular vision at the end of a manipulator reduces its availability in environments with obstacles. To deal with the problem, this study puts forward a target localization method using a laser and the monocular hand-eye vision. In the proposed method, the centre of the laser spot is obtained by the hand-eye vision, and the geometric relations among the laser emission point, light-spot and the optical axis of the camera are used to calculate the distance. Then, the D-H method is employed to construct the coordinate conversion system, so that the location of the target can be calculated. The measuring precision is negatively correlated with the distance, and it is suitable for the measurement in medium or short distance. Compared with the commonly used binocular measurement methods, the proposed method uses fewer cameras, which reduces the width of the measurement system on manipulators, and makes it more applicable to narrow workspace. Moreover, it also improves the effective load capacity of manipulators.

Towards a Magnetically-Actuated Laser Scanner for Endoscopic Microsurgeries

This paper presents the design and assembly of a novel magnetically-actuated endoscopic laser scanner device. The device is designed to perform 2D position control and high-speed scanning of a fiber-based laser for operation in narrow workspaces. The device includes laser focusing optics to allow non-contact incisions and tablet-based control interface for intuitive teleoperation. The performance of the proof-of-concept device is analyzed through controllability and usability studies. The computer-controlled high-speed scanning demonstrates repeatable results with 21[Formula: see text][Formula: see text]m precision and a stable response up to 48[Formula: see text]Hz. Teleoperation user trials were performed for trajectory-following tasks with 12 subjects, showing an accuracy of 39[Formula: see text][Formula: see text]m. The innovative design of the device can be applied to both surgical and diagnostic (imaging) applications in endoscopic systems.

Do Transperitoneal and Retroperitoneal Hand-Assisted Laparoscopic Nephroureterectomy have Different Effects on Intravesical Recurrence?

Objectives: Some studies have shown that in patients with upper tract urothelial carcinoma (UTUC) who have undergone hand-assisted laparoscopic nephroureterectomy (HALNU), the narrow working space and inevitable manipulation that occurs during the retroperitoneal approach (RP-HALNU) enhances tumor cell seeding in the bladder mucosa. This study was an attempt to investigate the differences in intravesical recurrence between transperitoneal HALNU (TP-HALNU) and RP-HALNU. Patients and Methods: From 1999 to 2011, a total of 197 patients with UTUC were enrolled. After excluding those with a previous history of bladder cancer, 170 patients were analyzed. Sixty-five of these underwent RP-HALNU, and 105 of these underwent TP-HALNU. The median follow-up periods were 39.2 and 46.2 months. Tumor location was divided into three groups: In the renal pelvis, in the ureter, and in both the renal pelvis and ureter. Results: There was no significant difference in the intravesical recurrence rate in relation to the different surgical approaches (P = 0.10), but tumor location in both the renal pelvis and ureter significantly increased the risk (hazard ratio [HR] = 3.11, P = 0.01). In addition, advanced T stage (HR = 9.63, P < 0.01) was the only significant risk factor related to death. Conclusions: In patients with UTUC, tumor location in both the renal pelvis and ureter determined higher susceptibility to intravesical recurrence. However, different surgical approaches to HALNU were not a significant risk factor for intravesical recurrence.

Research on a new omnidirectional mobile platform with heavy loading and flexible motion

This article presents an omnidirectional mobile platform with six mecanum wheels, which provide better carrying capacity than traditional four-wheel platform. Omnidirectional mobile platform with six mecanum wheels can withstand heavier load than the omnidirectional mobile platform with four mecanum wheels, which was used to transport large equipments used in marine and aerospace. Due to the small size, omnidirectional mobile platform with six mecanum wheels move more flexibly and reach desired position and pose easier in narrow workspace, compared with omnidirectional mobile platform with eight mecanum wheels whose disadvantage of large size offsets the advantage of zero turning radius. The kinematic model of the omnidirectional mobile platform with six mecanum wheel is established and verified through four kinds of motion state by the simulation (the omnidirectional mobile platform with six mecanum wheels moving along the Z axis, the X axis, the direction of which angle between positive X is 45°, and the omnidirectional mobile platform with six mecanum wheels rotating around the geometric center). The states of one wheel in failure have been analyzed in this article, taking into account the research levels of omnidirectional mobile platform with six mecanum wheels in the presence. The motion features of the platform with six mecanum wheels and four mecanum wheels are analyzed when certain wheels are locked-up or followed-up based on the force analysis of the wheels, and it proves that the platform with six mecanum wheels moves more stable than the platform with four mecanum wheels. In the presence of wheel failure, the platform still can move to the target location with gesture, due to its redundancy. This study contributes to the research of omnidirectional mobile platform with normal or failure mecanum wheels.

B-4 狭隘空間における溶接ヒュームの除去に関する数値予測

B-4 狭隘空間における溶接ヒュームの除去に関する数値予測

Theoretical analysis and design optimization of thermoelectric generator

Advantages of thermoelectric generators, such as no-moving parts, high stability, low noise and flexibly changeable volume, make them essential in power supply engineering. However, low generation power and large thickness restrict their usages. Purpose of the paper is to study influences of the common parameters, including working temperature, area-to-length ratio of n/p type semiconductors and thickness of electrical conducting plate, on performance of thermoelectric unit using theoretical and numerical methods. Based on the analysis, thermoelectric components can be redesigned to obtain optimal power output and efficiency of the generator. The new designed thermoelectric unit is composed of n/p type semiconductors in a cuboid shape made of functionally-graded materials, and upper/left/right electrical conducting plates with optimal thickness. The proposed generator has minimized thickness, high efficiency and enhanced power output. Therefore, volume and cost of the generator can be notably reduced, making it suitable for applications in special occasions, such as low-grade heat sources, narrow working spaces and large rated power output.

Development of a novel paediatric surgical assist robot for tissue manipulation in a narrow workspace

PurposePaediatric congenital esophageal atresia surgery typically requires delicate and dexterous operations in a narrow and confined workspace. This study aims to develop a novel robot assisted surgical system to address these challenges.Design/methodology/approachThe proposed surgical robot consists of two symmetrical slave arms with nine degree of freedoms each. Each slave arm uses a rigid-dexterous configuration and consists of a coarse positioning manipulator and a distal fine operation manipulator. A small Selective Compliance Assembly Robot Arm (SCARA) mechanism was designed to form the main component of the coarse positioning unit, ensuring to endure large forces along the vertical direction and meet the operational demands. The fine positioning manipulator applied the novel design using flexible shafts and universal joints to achieve delicate operations while possessing a high rigidity. The corresponding kinematics has been derived and then was validated by a co-simulation that was performed based on the combined use of Adams and MATLAB with considering the real robot mass information. Experimental evaluations for the tip positioning accuracy and the ring transfer tasks have been performed.FindingsThe simulation was performed to verify the correctness of the derived inverse kinematics and demonstrated the robot’s flexibility. The experimental results illustrated that the end-effector can achieve a positioning accuracy within 1.5 mm in a confined 30 × 30 × 30 mm workspace. The ring transfer task demonstrated that the surgical robot is capable of providing a solution for dexterous tissue intervention in a narrow workspace for paediatric surgery.Originality/valueA novel and compact surgical assist robot is developed to support delicate operations by using the dexterous slave arm. The slave arm consists of a SCARA mechanism to avoid experiencing overload in the vertical direction and a tool manipulator driven by flexible shafts and universal joints to provide high dexterity for operating in a narrow workspace.

Do transperitoneal and retroperitoneal hand-assisted laparoscopic nephroureterectomy have different effects on intravesical recurrence?

ObjectivesSome studies have shown that in patients with upper tract urothelial carcinoma (UTUC) who have undergone hand-assisted laparoscopic nephroureterectomy (HALNU), the narrow working space and inevitable manipulation that occurs during the retroperitoneal approach (RP-HALNU) enhances tumor cell seeding in the bladder mucosa. This study was an attempt to investigate the differences in intravesical recurrence between transperitoneal HALNU (TP-HALNU) and RP-HALNU. MethodsFrom 1999 to 2011, a total of 197 patients with UTUC were enrolled. After excluding those with a previous history of bladder cancer, 170 patients were analyzed. 65 of these underwent RP-HALNU, and 105 of these underwent TP-HALNU. The median follow-up periods were 39.2 and 46.2 months. Tumor location was divided into three groups: in the renal pelvis, in the ureter, and in both the renal pelvis and ureter. ResultsThere was no significant difference in the intravesical recurrence rate in relation to the different surgical approaches (p = 0.10), but tumor location in both the renal pelvis and ureter significantly increased the risk (Hazard ratio [HR] = 3.11, p = 0.01). In addition, advanced T stage (HR = 9.63, p < 0.01) was the only significant risk factor related to death. ConclusionsIn patients with UTUC, tumor location in both the renal pelvis and ureter determined higher susceptibility to intravesical recurrence. However, different surgical approaches to HALNU were not a significant risk factor for intravesical recurrence.

Feasibility of Transvesical Robotic VVF Repair in Porcine Model.

Extraperitoneal transvesicoscopic vesicovaginal fistula (VVF) repair has received limited use because of its narrow working space, longer operation time, and technical difficulty. The present study describes the feasibility of robotic-assisted transvesicoscopic VVF repair in an animal model. Two Yorkshire swine underwent robotic-assisted laparoscopic (RAL) VVF repair. With the 4 trocars, an artificial VVF was made in the supratrigonal area and VVF repair was performed in 3 layers as in open VVF repair methods. The mean operation time was 108 minutes. The operation time was prolonged in 1 case due to weak fixation of bladder to anterior abdominal wall. Equipment interference did not occur. Tissue manipulation and suturing were easy. The results of this study suggest that extraperitoneal RAL procedures for VVF repair may be an effective minimally invasive modality with reduced morbidity. A shorter operation time and easy suturing technique were the distinct merits of the extraperitoneal RAL technique.

All Arthroscopic Remnant-Preserving Technique to Reconstruct the Lateral Ankle Ligament Complex

Arthroscopic lateral ankle ligament reconstruction has been recently advocated. But this technique has not been popularized because of the technical complexity and potential iatrogenic injury. Because the talocalcaneal and calcaneofibular ligaments are extra-articular structures, how to efficiently view and address them is a difficult task. Limited dissection outside the capsule to form a working space is required, but aggressive dissection is harmful for tissue healing although it is helpful for visualization and instrumentation. Because almost the entire talar body is covered by articular cartilage, it is very difficult to safely make a bone tunnel without damaging the cartilage. The remnants of the lateral ankle ligament have proprioceptive sensors that are important for functional stability, but it is difficult to perform anatomical reconstruction arthroscopically while preserving them because of the narrow working space. Furthermore, how to properly tension the reconstructed ligaments in such a narrow working space is also a very difficult task. We have designed a technique that preserves the remnants of lateral ankle ligaments, and all of the above-mentioned problems have been successfully addressed. We have used this technique clinically, and only minor complications occurred.