Mechanical Arm Research Articles

A head-to-head comparison of the first choice and crossover lead extraction tool: laser vs. mechanical

Abstract Funding Acknowledgements Type of funding sources: None. Background During transvenous lead extraction (TLE) longer dwelling time often requires the use of powered sheaths. Purpose This study aimed to compare outcomes with the laser and mechanical tools. Methods Single-center data from consecutive patients undergoing TLE between 2012 and 2021 were retrospectively analyzed. Efficacy and safety of the primary extraction tool were compared. Procedures requiring crossover between powered sheaths were also analyzed. Moreover, we examined the efficacy of each level of the stepwise approach. Results Out of 166 patients 142 (age 65.4±13.7 years) underwent TLE requiring advanced techniques with 245 leads (dwelling time 9.4±6.3 years). Laser sheaths were used in 64.9%, mechanical sheaths in 35.1% of the procedures as primary extraction tools. Procedural success rate was 85.5% with laser and 82.5% with mechanical sheaths (p=0.552). Minor and major complications were observed in similar rate. Procedural mortality occurred only in the laser group in case of 3 patients. Crossover was needed in 19.5% after laser and in 12.8% after mechanical extractions (p=0.187). Among crossover procedures only clinical success favored the secondary mechanical arm (87.1% vs. 54.5%, aOR: 0.09, 95%CI: 0.01-0.79, p=0.030). After step-by-step efficacy analysis, procedural success was 64.9% with the first-line extraction tool, 75.1% after crossover, 84.5% with bailout femoral snare, and 91.8% by non-emergency surgery (Figure). Conclusion The efficacy and safety of laser and mechanical sheaths were similar in our study, however in the subgroup of crossover procedures mechanical tools had better performance regarding clinical success. Device diversity seems to be indispensable in order to achieve the most optimal outcomes.

A case report of re-implanting a neglected avulsion of supraspinatus tendon by arthroscopic and open surgeries.

IntroductionRotator cuff constitutes a mechanical arm and an important stabilizing factor for the shoulder joint, and the supraspinatus muscle is the initiator of the movement of arm in the abduction direction. Rotator cuff injuries constitute an important part of the shoulder pain, and many cases are managed conservatively, nevertheless, open or arthroscopic surgery remains a must in many cases.Case reportWe present the case of a patient in the sixth decade of life who complained of absence of abduction movement in his right shoulder three months ago after he lifted a heavy object. The clinical examination showed a positive sign of drop arm and other clinical signs indicating absence of supraspinatus muscle function. The MRI also showed a full-thickness tear of the supraspinatus tendon and its retraction away from its original inserting point on the greater tuberosity of the humerus. The case was managed by re-implanting the ruptured tendon by combining arthroscopic and open surgeries and using two anchors with slipable sutures, adopting the principles of duplicated knots and multiple transverse entry through the tendon to get a firm fulcrum. The results were clearly good after rehabilitation with a wide and powerful ROM (Range of Motion).DiscussionMany cases of RCT (Rotator Cuff Tears) are concretively managed by using corticosteroids injections into the subacromial space with results of significant improvement in symptoms, and arthroscopic surgery is of increasing importance in preventing the development of small partial or full thickness tears and in reconnecting complete or avulsion tears early. The current case is characterized by a clear contraction of the completely avulsed tendon with severe adhesions due to neglection of the case for several months, which made the possibilities of arthroscopic surgeries limited only by acromioplasty, loosening some adhesions and preparation of the footprint, as well as making open surgery mandatory to give a wide area for doubling the suturing layers and then re-implanting the avulsed tendon into its original anchor.ConclusionNeglect and delay in managing full-thickness tears in the supraspinatus tendon are the important reasons for the occurrence of adhesions and fibrosis, which in turn hinder the process of re-implanting the ruptured tendon at its original anchor through arthroscopic surgery, so that open surgery becomes the mandatory solution. It is necessary to use anchors with slipable threads and to focus on doubling the suturing layers with repeatedly entering through the muscle tendon to reduce it to the footprint firmly and strongly by tightening the slipable threads through the anchors.

Accurate THz ellipsometry using calibration in time domain.

We report on the realisation of a customized THz time domain spectroscopic ellipsometer (THz-TDSE) based on fiber-coupled photoconductive antennas, operating in a wide range of incident angles and allowing also standard transmission spectroscopy without any optical realignment. To ensure accurate parameter extraction for a broad range of materials, we developed a fast and effective algorithm-assisted method to calibrate the setup and compensate for the nonideality in the response of the THz system. The procedure allows to minimise errors induced by imperfect response of the antennas and polarizers, imprecise setting of the impinging and receiving angles in the goniometric mechanical arms, and unavoidable mismatches in the THz beam optics. Differently from other calibration methods applied in the literature, our approach compares in time domain the ellipsometric derived electric field s- and p-polarised components at a given angle of incidence with the reconstructed ones, attained by using the complex dielectric function of a known sample. The calibrated response is determined with high precision by setting the system in transmission mode. In order to validate the technique, ellipsometric measurements have been carried out at various angle of incidences on a number of materials both in solid and liquid form, and their data compared with what obtained by conventional THz spectroscopy. Results show that THz-TDSE accompanied with an accurate calibration procedure is an effective technique for material characterization, especially in case of samples with a high absorption rate that are not easily investigated through transmission measurements.

Dynamic simulation of complex multi-hinge space flap mechanism

Dynamics simulation of large civil aircraft complex multi-hinge space flap mechanism was studied, and a set of dynamics simulation modeling method of complex multi-hinge space flap mechanism based on Motionview was proposed. Firstly, a moving digital prototype of the complex multi-hinge space mechanism was constructed. The multi-point constraint RBE3 element was used to associate the intersection points of the rigid multi-hinge mechanism to the body of the flap surface considering flexibility, and the rigid-flexible coupling dynamic model of the flap mechanism was formed. The dynamics simulation of the mechanism was carried out under the aerodynamic load conditions of cruise, take-off and landing, the driving torque and hinge point load dynamics indexes of the complex multi-hinge space flap mechanism were obtained. The simulation results show that the driving arm of the inner mechanism bears most of the lateral load from the flap wing surface, the radial direction of the joints bearing at each hinge bears the aerodynamic pulling force from the flap wing surface. And the inner mechanism of the flap is the main bearing part, the load capacity of the inner rocker arm is almost four times that of the outer rocker arm. The dynamic simulation research can provide a certain reference for the design and improvement of the complex multi-hinge space flap mechanism.

Function Integration through Design for Hybrid Integrating Additive Manufacturing Technologies

AbstractAdditive manufacturing (AM) technologies enable the design of new products due to their potentials. The potential of function integration can be extended through a combination of AM with a component integrating technology forming a hybrid integrating additive manufacturing technology (hiAM). With a created development method optimization areas within a product are identified on a functional level using characteristics, structural configurations and integrated functional areas. These are derived analysing examples in literature. The method is applied to a mechanical arm and hand prosthesis.

Pengembangan Bag Valve Mask (BVM) Otomatis

<em><span>Ventilators are one of the medical devices that are needed as a breathing apparatus for COVID-19 patients who have respiratory problems. One of the low-cost ventilators currently being developed by several domestic institutions is the ambu bag-based ventilator. The point is an air bag (bag) that is pressed by two carefully controlled automatic clamps, so that it can reach all, while taking into account portability, aesthetics and ease of manufacture. Therefore, the Bag Valve Mask (BVM) or ambu bag is an emergency option to replace the function of the ventilator. This study aims to make an ambu bag that can be applied as a portable mechanical ventilator. Thus, the ambu bag which was originally used manually can be used automatically like a ventilator machine in general. In determining the type of mechanical arm pressure, several parameters such as minute volume, respiratory rate, and tidal volume are used. As recommended by the American Heart Association (AHA) that the tolerance limit for the RR value is +/-10 BPM, it can be said that the automatic BVM as a result of this study can be used with or without a reservoir as needed or with the addition of oxygen</span></em>

On novel hydrogels based on poly(2-hydroxyethyl acrylate) and polycaprolactone with improved mechanical properties prepared by frontal polymerization

This work aimed to improve the mechanical properties of poly(2-hydroxyethyl acrylate) (PHEA)-based hydrogels by performing their polymerization in the presence of an ad hoc synthesized star-shaped polymer, whose arms are composed of a biopolymer, i.e., polycaprolactone (PCL) end-capped with acrylic units to act as a crosslinker for PHEA. Indeed, this system was designed to have (i) biocompatible, biodegradable, and mechanical strong arms as well as (ii) a star structure with acrylic functionalities to promote the crosslinking of the material. 1H NMR, IR and TGA measurements confirmed the star PCL functionalization, which was carried out starting from a hydroxyl-terminated polymer. Hydrogels were prepared by varying the concentration of the synthesized star polymer, and the properties of the materials obtained by frontal (FP) and bulk polymerization (BP) were compared. Moreover, to evaluate the specific effect of PCL-star-4-2 k-tetraacrylate (PCL-TA) on the crosslinking of the systems, samples were also synthesized using a commercial acrylate crosslinker. For what concerns the frontal polymerization process, fronts were found to be stable in the presence of PCL-TA. The thermal characterization results showed a significant decrease in the PHEA glass transition temperature with increasing PCL-TA content, which was particularly evident in the samples prepared by FP. This result can be attributed to the partial miscibility of the two polymers, which become compatible during the polymerization process by forming a copolymer system. This was confirmed by analyzing the thermal behavior of hydrogels polymerized in the presence of a hydroxyl terminated PCL, i.e., a polymer without active functional end groups. The samples synthesized by FP with the star polymer and the commercial crosslinker, as well as neat PHEA, were subjected to mechanical tests. The mechanical behavior of PCL-based hydrogels was outstanding, exhibiting three time higher modulus than that of crosslinked PHEA, and were structurally stable even under high compression loadings. This remarkable property, combined with the fast and efficient polymerization method and the environmentally friendly properties of PCL, make the developed hydrogels promising systems for practical applications in various fields.

The Role and Application of 3D Printer in the Automobile Industry

In this paper, we will discuss Additive Manufacturing, which is regarded as one of the most significant innovative industrial processes in the coming years, especially in the automobile industry. As of late, the utilization of added substance fabricating (AM) in the plan has gotten a ton of consideration. To print building parts utilizing total based materials, metals, or polymers, huge mechanical arm and gantry frameworks have been created. The robotization of the assembling cycle, the serious level of plan freedom, and the subsequent extension for streamlining are altogether huge benefits of AM. We discussed all of the terms that made this technology superior to conventional production and prototyping processes in this paper. In the automobile industry, additive manufacturing is a process that follows the industries to manufacture different components.3D printing otherwise called additive manufacturing has the ability to democratize mechanical part production. 3D printing machines can find their way into all aspects of the automotive industry in the future.

Mechanical versus bioprosthetic valve for aortic valve replacement: systematic review and meta-analysis of reconstructed individual participant data.

The aim of this study was to compare biological versus mechanical aortic valve replacement. We searched MEDLINE, Scopus and Cochrane Library databases for randomized clinical trials and propensity score-matched studies published by 14 October 2021 according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses statement. Individual patient data on overall survival were extracted. One- and two-stage survival analyses and random-effects meta-analyses were conducted. A total of 25 studies were identified, incorporating 8721 bioprosthetic and 8962 mechanical valves. In the one-stage meta-analysis, mechanical valves cumulatively demonstrated decreased hazard for mortality [hazard ratio (HR): 0.79, 95% confidence interval (CI): 0.74-0.84, P < 0.0001]. Overall survival was similar between the compared arms for patients <50 years old (HR: 0.88, 95% CI: 0.71-1.1, P = 0.216), increased in the mechanical valve arm for patients 50-70 years old (HR: 0.76, 95% CI: 0.70-0.83, P < 0.0001) and increased in the bioprosthetic arm for patients >70 years old (HR: 1.35, 95% CI: 1.17-1.57, P < 0.0001). Meta-regression analysis revealed that the survival in the 50-70 year-old group was not influenced by the publication year of the individual studies. No statistically significant difference was observed regarding in-hospital mortality, postoperative strokes and postoperative reoperation. All-cause mortality was found decreased in the mechanical group, cardiac mortality was comparable between the 2 groups, major bleeding rates were increased in the mechanical valve group and reoperation rates were increased in the bioprosthetic valve group. Survival rates seem to not be influenced by the type of prosthesis in patients <50 years old. The survival advantage in favour of mechanical valves is observed in patients 50-70 years old, while in patients >70 years old bioprosthetic valves offer better survival outcomes.

Bed-mounted laparoscopic surgical robot system with novel positioning arm mechanism.

Commercialised laparoscopic surgical robotic systems require a large operating room and can only be used in large hospitals. If the robotic system is to be used in a small- or medium-sized hospital, the occupied volume must be reduced further. In this paper, we propose a bed-mounted system that can be installed in a general operating room. Furthermore, we proposed a novel positioning arm suitable for a bed-mounted surgical robot system. The surgical possibility of the proposed bed-mounted system has been verified. Furthermore, the surgical possibility of the proposed system was confirmed using in vivo animal experiments. A bed-mounted laparoscopic robotic system and a novel positioning arm was proposed. The study's ultimate goal is to enable robotic surgery in small and medium-sized hospitals by introducing the proposed bed-mounted laparoscopic robot system, allowing many people to receive high-quality medical services.

A Low-Cost Three-Dimensional Printed Retractor for Transforaminal Lumbar Interbody Fusion

The authors developed a low-cost surgical retractor to improve surgeon’s comfort and facilitate pedicle screw insertion in transforaminal lumbar interbody fusion surgery. The retractor was designed using three-dimensional (3D) modeling software and produced with the help of a 3D printer. It was attached to a mechanic retractor arm. The retractor was anchored to the transverse process through a concave notch at its tip, visualizing the junction between the transverse process and the superior articular process. The gutter-shaped body of the retractor helped stay within the ideal trajectory during screw insertion. The retractor was tested in 20 patients undergoing transforaminal lumbar interbody fusion with satisfactory results. Future models will be generated suitable for surgery of the cervical and thoracic spine.

Entropy Could Quantify Brain Activation Induced by Mechanical Impedance-Restrained Active Arm Motion: A Functional NIRS Study.

Brain activation has been used to understand brain-level events associated with cognitive tasks or physical tasks. As a quantitative measure for brain activation, we propose entropy in place of signal amplitude and beta value, which are widely used, but sometimes criticized for their limitations and shortcomings as such measures. To investigate the relevance of our proposition, we provided 22 subjects with physical stimuli through elbow extension-flexion motions by using our exoskeleton robot, measured brain activation in terms of entropy, signal amplitude, and beta value; and compared entropy with the other two. The results show that entropy is superior, in that its change appeared in limited, well established, motor areas, while signal amplitude and beta value changes appeared in a widespread fashion, contradicting the modularity theory. Entropy can predict increase in brain activation with task duration, while the other two cannot. When stimuli shifted from the rest state to the task state, entropy exhibited a similar increase as the other two did. Although entropy showed only a part of the phenomenon induced by task strength, it showed superiority by showing a decrease in brain activation that the other two did not show. Moreover, entropy was capable of identifying the physiologically important location.

Operation space analysis and trajectory planning of mechanical arm in narrow space for GIS (gas insulated switchgear) inspection robot

Purpose The purpose of this paper is to achieve optimal climbing control of the gas-insulated switchgear (GIS) robot, as the authors know that the GIS inspection robot is a kind of artificial intelligent mobile equipment which auxiliary or even substitute human labor drive on the inner wall of the gas-insulated metal enclosed switchgear. The GIS equipment fault inspection and maintenance can be realized through the robot manipulator on the mobile platform and the camera carried on the fuselage, and it is a kind of intelligent equipment for operation. To realize the inspection and operation of the GIS equipment pipeline without blind spots, the robot is required to be able to travel on any wall inside the pipeline, especially the top of the pipeline and both right and left sides of the pipeline, which requires the flexible climbing of the GIS inspection robot. The robot device has a certain adsorption function to ensure that the robot is fully attached to the wall surface. At the same time, the robot manipulator can be used for collision-free obstacle avoidance operation planning in the narrow operation space inside the GIS equipment. Design/methodology/approach The above two technologies are the key that the robot completes the GIS equipment inspections. Based on this, this paper focuses on modeling and analysis of the chassis adsorption characteristics for the GIS inspection robot. At the same time, the Denavit Hartenberg (D-H) coordinate model of the robot arm system has been established, and the kinematics forward and inverse solutions of the robot manipulator system have been derived. Findings The reachable working space point cloud diagram of the robot manipulator in MATLAB has been obtained based on the kinematics analysis, and the operation trajectory planning of the robot manipulator using the robot toolbox has been obtained. The simulation results show that the robot manipulator system can realize the movement without collision and obstacle avoidance. The space can cover the entire GIS pipeline so as to achieve no blind area operation. Originality/value Finally, the GIS inspection robot physical prototype system has been developed through system integration design, and the inspection, maintenance operation experiment has been carried out in the actual GIS equipment. The entire robot system can complete the GIS equipment inspection operation soundly and improve the operation efficiency. The research in this paper has important theoretical significance and practical application value for the optimization design and practical research of the GIS inspection robot system.

Guidance method of simulating weld trajectory between planes based on single-point laser

Abstract In the face of problems such as welding of small objects or too small welding space, an application method of welding small plane intersecting objects based on point laser was proposed. The demonstration points pointing to different planes were preset, and the laser displacement sensor was driven to measure the physical value by simulating the sharp workpiece of the welding gun. Multiple projections at different locations were made on a certain plane of the welding object, so as to ensure that the laser points were not collinear and obtain the laser point parameter set. The plane equation was solved respectively according to the planes pointed by different demonstration points, and a geometric model was built. The equation of the intersecting line between the planes in the welding object was calculated. The points on the line were obtained as the welding start points. The workpiece tip was controlled to move along the intersection direction by the mechanical arm, so as to achieve the weld effect.

Design, Modeling and Motion Simulation of a Setback Arming Mechanism under Weak Acting Forces

Abstract A parallel two-degree-of-freedom (two-DOF) setback arming mechanism was designed in this study according to acceleration signal characteristics of weak launch and service conditions. A model of an inertia switch with a low g-feature was designed to be used in the electromechanical fuze of the proposed mechanism. Simulations were conducted to analyze the motion characteristics of the inertia switch that was based on the parallel two-DOF spring-mass system under the launch overload and the service dropping overload. The reliability and safety of the inertia switch were validated.

Design of a Novel Long-Reach Cable-Driven Hyper-Redundant Snake-like Manipulator for Inspection and Maintenance

Robotic inspection and maintenance are gaining importance due to the number of different scenarios in which robots can operate. The use of robotic systems to accomplish such tasks has deep implications in terms of safety for human workers and can significantly extend the life of infrastructures and industrial facilities. In this context, long-reach cable-driven hyper-redundant robots can be employed to inspect areas that are difficult to reach and hazardous environments such as tanks and vessels. This paper presents a novel long-reach cable-driven hyper-redundant robot called SLIM (Snake-Like manipulator for Inspection and Maintenance). SLIM consists of a robotic arm, a pan and tilt mechanism as end-effector, and an actuation box that can rotate and around which the arm can wrap. The robot has a total of 15 degrees of freedom and, therefore, for the task of positioning the tool centre point in a bi-dimensional Cartesian space with a specific attitude, it has 10 degrees of redundancy. The robot is designed to operate in harsh environments and high temperatures and can deploy itself up to about 4.8 m. This paper presents the requirements that drove the design of the robot, the main aspects of the mechanical and electronic systems, the control strategy, and the results of preliminary experimental tests performed with a physical prototype to evaluate the robot performances.

Single-position robot-assisted versus laparoscopic antegrade bilateral inguinal lymphadenectomy for penile cancer: A retrospective controlled study

ObjectivesThe main purpose of this study was to compare the surgical strategy and clinical outcomes of single-position robotic assisted laparoscopic anterograde bilateral inguinal lymphadenectomy for penile cancer. Materials and methods21 patients were diagnosis with squamous cell carcinoma and identified from March 2010 to December 2020 in our department. Ten patients were received single-position robotic assisted laparoscopic anterograde bilateral inguinal lymphadenectomy (robot-assisted group), and eleven patients underwent laparoscopic inguinal lymphadenectomy (laparoscopic group). Preoperative physical examination and related auxiliary examinations all indicated bilateral inguinal lymph node enlargement, and there was no distant metastasis patient presented during the follow-up period. ResultsThere was no intraoperative conversion to open surgery. The operation time under robot-assisted group was 104 ± 13 min which was significantly shorter than laparoscopic group (136 ± 11 min, P < 0.01). The average number of lymph nodes was 22.2 ± 4.5 of both sides in robot-assisted group, which was statistically different compared with laparoscopic group (15.4 ± 3.1, p < 0.01). Moreover, there was significant difference of hospitalization cost between two groups (CNY 67429 ± 5586 vs 28582 ± 3774, P < 0.01). No differences in operation time, blood loss, and length of stay were recorded. ConclusionsThe single-position robotic assisted laparoscopic anterograde bilateral inguinal lymphadenectomy reveals with shorter operating time, and better surgical effect, Moreover, we prefer to no change the trocars layout and mechanical arm system during the operation.

Modelling, simulation and experimental validation of wheel and arm locomotion based wall-climbing robot

AbstractThis article presents modelling, simulation, and development of a wall-climbing robot based on coupled wheel and arm-type locomotion mechanism. The developed robot consists of two mobile modules connected with a robot arm mechanism. The actuation of the robot arm is inspired by inchworm locomotion, particularly during wall-to-wall transition, obstacle avoidance, and uneven surface locomotion. Easiness in the interchanging of wheel to arm and vice versa makes the robot more effective compared to previously developed wall-climbing robots. The kinematic and dynamic model for the proposed coupled wheel and arm locomotion concept has been established. A combination of particle swarm optimization (PSO) and proportional, integral, derivatives (PID) feedback control algorithm has been developed using MATLAB to simulate the different cases of robot motions. The developed prototype of the wall-climbing robot is used to verify the coupled wheel and arm locomotion concept in various wall climbing scenarios. The simulation and experimental findings show good comparisons and validate the model-based design of the wall-climbing robot.

A Study of the Vibration Characteristics of Flexible Mechanical Arms for Pipe String Transportation in Oilfields

During the drilling and repairing of wells, the pipe string transfer equipment has a high work frequency. The movement accuracy, response speed, and controllability of the equipment have significant impacts on the stability. In this paper, we propose an analysis method of mechanical arms to lift pipe strings using a rigid–flexible coupling model. With the mechanical arm as a flexible body and the mechanical hand as a rigid body, a numerical calculation model of the rigid-flexible coupling of the system was established based on the Lagrangian equation. ADAMS and Ansys software were applied to numerical simulations of this system to investigate the lifting characteristics, the influence of the operation parameters and structure parameters, and the contact collision analysis of the mechanical arm. The conditions of rigid–flexible modeling for the multi-body system and the main factors affecting the vibration characteristics of the flexible arm are described. We conclude that the arm should be modeled as a rigid body if the structure parameter [w/l] (elastic deformation/length) is between 1/650 and 1/1000, the system can be modeled as a rigid–flexible coupling if [w/l] is between 1/400 and 1/650, and the arm should be modeled as a flexible body and the influence and compensation of the control method should be considered if [w/l] is between 1/250 and 1/400.

Contour recognition method of Hall-effect-based whisker sensor

This paper introduces a novel Hall-effect-based whisker sensor and proposes a contour recognition algorithm for distinguishing and recognizing objects. The mechanical arm drives the sensor to move according to the contour recognition algorithm in the experiments, and the object contour is distinguished and recognized by processing the detected spatial magnetic field data. The results of identifying the measured object with harder carbon fiber and softer ABS whiskers were compared and analyzed, and a new design was proposed based on the advantages of soft and hard materials. The newly designed whisker with glass fiber and stainless steel rod nested reduced the contour recognition error to 4.1%. The experimental results showed that the sensor could distinguish the contour of the straight line and circular objects, and the glass fiber and stainless steel rod nested sensor had a better recognition effect.