Small Workspace Research Articles

Characterization of Friction within a Novel 3 mm Wristed Robotic Instrument

Surgical robotic tools are being developed for a variety of surgical procedures that are executed within small workspaces. Novel designs of miniaturized cable-actuated surgical tools for cleft palate repair have previously been developed. However, the behavior and significance of friction within these tools are largely unknown. A study was conducted to investigate the friction in a pulleyless 3 mm diameter wristed instrument. The wrist utilizes cable guide channels that allow for miniaturization at the cost of increased friction. An experimental rig was developed to measure friction within the wrist link mechanism when the tool is positioned at various pitch angles. A strong relationship between the cable tension and the tool’s pitch angle was found as a result of friction. The cable tension increased as the pitch angle approached extreme values (percent increases in the cable tension of 33% and 67.3% at a pitch of 90° and −90°, respectively). However, the resultant cable tension was below the failure strength of the cable, indicating that the design is feasible. The results of this study would be useful to those considering the design of miniature robotic surgical tools that are cable-driven. Significant tool reduction can be achieved by employing static guide channels for the cables, forgoing the use of additional moving components like pulleys while maintaining cable tension well within its break strength. Future work in the design and optimization of novel miniaturized wrist mechanisms should consider frictional effects and their impact on mechanism function.

On the design of a macro‐micro parallel manipulator for cochlear microrobot operations

AbstractBackgroundThe method of stem cell transfer to narrow cochlear canals in vivo to generate hair cells is still an unclear operation. Thus, the development of any possible method that will ensure the usage of medical microrobots in small cochlear workspaces is a challenging procedure.MethodsThe current study tries to introduce a macro‐micro manipulator system composed of a 6‐DoF industrial serial manipulator as a macro manipulator and a proposed 5‐DoF parallel manipulator with dual end effectors as a micro manipulator carrying permanent magnets for tetherless microrobot actuation inside the cochlea.ResultsThroughout the study, structural synthesis and kinematic analysis of the proposed micro manipulator were introduced. A prototype of the manipulator was manufactured and its hardware verification procedures were carried out using motion capture cameras and surgical navigation registration methodologies.ConclusionsFollowing motion training, the assembled macro‐micro manipulator was successfully utilised to actuate a microrobot placed inside a manufactured cochlea mockup model.

Enabling extracorporeal ultrasound imaging with the da Vinci robot for transoral robotic surgery: a feasibility study.

Transoral robotic surgery (TORS) is a challenging procedure due to its small workspace and complex anatomy. Ultrasound (US) image guidance has the potential to improve surgical outcomes, but an appropriate method for US probe manipulation has not been defined. This study evaluates using an additional robotic (4th) arm on the da Vinci Surgical System to perform extracorporeal US scanning for image guidance in TORS. A stereoscopic imaging system and da Vinci-compatible US probe attachment were developed to enable control of the extracorporeal US probe from the surgeon console. The prototype was compared to freehand US by nine operators in three tasks on a healthy volunteer: (1) identification of the common carotid artery, (2) carotid artery scanning, and (3) identification of the submandibular gland. Operator workload and user experience were evaluated using a questionnaire. The robotic US tasks took longer than freehand US tasks (2.09x longer; ) and had higher operator workload (2.12x higher; ). However, operator-rated performance was closer (avg robotic/avg freehand=0.66; ), and scanning performance measured by MRI-US average Hausdorff distance provided no statistically significant difference. Extracorporeal US scanning for intraoperative US image guidance is a convenient approach for providing the surgeon direct control over the US image plane during TORS, with little modification to the existing operating room workflow. Although more time-consuming and higher operator workload, several methods have been identified to address these limitations.

Upper gastrointestinal endoscopic submucosal dissection using an ultrathin endoscope: a retrospective, single-center evaluation.

Recent studies have reported the therapeutic use of endoscopic submucosal dissection (ESD) using an ultrathin endoscope for targeting pharyngeal and distal side lesions in the stenosis or as a less invasive treatment via the nasal route. However, the effectiveness and safety of these treatments remain undetermined. Therefore, this study aimed to review treatment outcomes and discuss the advantages and precautions of the treatments based on our experience. This study included 13 patients with 14 lesions who underwent 14 sessions of upper gastrointestinal ESD using an ultrathin endoscope between December 2021 and August 2023. The outcome measures included lesion background, en bloc resection rate, en bloc complete resection rates, and incidence of adverse events (including post-operative bleeding, intraoperative perforation, and delayed perforation). The lesions in the esophagus, stomach, and duodenum were eight, three, and three, respectively, and the median length (range) of each located lesion was 16.5 (6-26), 17 (9-36), and 10 (4-16) mm, respectively. En bloc resection and en bloc complete resection rates were 100 and 92.9%, respectively. The only adverse event was an intraoperative perforation observed during duodenal ESD, resulting from the assistant's inadvertent expansion of the SOUTEN at the final dissection stage. Our results demonstrate that ESD with an ultrathin endoscope effectively reaches lesions in difficult locations and enables treatment within a small working space. Therefore, ESD using an ultrathin endoscope is a treatment option for lesions located distally to gastrointestinal stenosis, highly fibrotic lesions, and duodenal tumors.

Predictors of surgical difficulty according to surgical proficiency in robot-assisted radical prostatectomy.

Robot-assisted radical prostatectomy (RARP) is a standard treatment for localized prostate cancer. We previously reported that a large amount of pelvic visceral fat and a small working space, as measured by three-dimensional image analysis, were significantly associated with prolonged console time in RARP, and these factors could be alternatives to the more clinically practical body mass index (BMI) and pelvic width (PW), respectively. Herein, we further investigated whether surgical proficiency affected surgical difficulty as measured by console time. Medical records of 413 patients who underwent RARP between 2014 and 2020 at our institution were reviewed. Surgeons who had experience with over and under 100 cases were defined as "experienced" and "non-experienced," respectively. Multivariate logistic regression analyses were performed to identify factors that prolonged console time. The median console times for RARP by experienced and non-experienced surgeons were 87.5 and 149.0min, respectively; a difficult case was defined as one requiring time greater than the median. Among inexperienced surgeons, higher BMI (p < 0.001, odds ratio: 1.89) and smaller PW (p = 0.001, odds ratio: 1.86) were significant factors that increased console time; the complication rate was increased in patients with these factors. However, these factors did not significantly affect the console time or complication rate among experienced surgeons. This study demonstrates that experienced surgeons may be able to overcome obesity- and small workspace-related surgical difficulties. The current analysis may provide useful information regarding unpredictable surgical risks and identify suitable cases for novices.

Study on the error characteristics of transformer for primary and secondary fusion used in pole-mounted switchgear

The fusion of primary and secondary functions refers to integrating the function of primary equipment and secondary equipment together. If doing so, the working condition of the equipment for primary and secondary fusion becomes more and more complex and bad, especially the transformer working in the smaller workspace after fusing. Therefore, this paper focuses on the transformer used in primary and secondary fusion pole-mounted Switchgear and establishes the temperature field and electric field simulation model of the primary and secondary fusion pole-mounted switchgear transformer, respectively, and the temperature rise and the environment electric field interference influencing the error of transformer are analyzed as well. When the working environment temperature ranges from -40 to 70°C, the maximum error of low-power current transformers and resistive voltage transformers is 0.1246% and 0.0371%, respectively. The electric field is one of the main factors influencing resistive voltage transformers, which makes ratio errors and angle errors -0.256% and -22.5392’, respectively. The research reveals that under conditions, the error is mainly dependent on temperature rise and electric field. These two factors have a great influence on the error, while the transformers still have enough reliability.

Performance evaluation and dimensional optimization design of planar 6R redundant actuation parallel mechanism

AbstractAiming at the problems of small good workspace, many singular configurations, and limited carrying capacity of non-redundant parallel mechanisms, a full-redundant drive parallel mechanism is designed and developed, and its performance evaluation, good workspace identification, and scale optimization design are studied. First, the kinematics analysis of the planar 6R parallel mechanism is completed. Then, the motion/force transmission performance evaluation index of the mechanism is established, and the singularity analysis of the mechanism is completed. Based on this, the fully redundant driving mode of the mechanism is determined, and the good transmission workspace of the mechanism in this mode is identified. Then, the mapping relationship between the performance and scale of the mechanism is established by using the space model theory, and the scale optimization of the mechanism is completed. Finally, the robot prototype is made according to the optimal scale, and the performance verification is carried out based on the research of dynamics and control strategy. The results show that the fully redundant actuation parallel mechanism obtained by design optimization has high precision and large bearing capacity. The position repeatability and position accuracy are 0.053 mm and 0.635 mm, respectively, and the load weight ratio can reach 15.83%. The research results of this paper complement and improve the performance evaluation and scale optimization system of redundantly actuated parallel mechanisms.

Selective-collective scalable locomotion control of helical magnetic swimmers within confined channels using global magnetic fields

Achieving selective-individual and collective control over multiple magnetic microrobots remains a formidable challenge. Existing techniques for controlling identical magnetic swimmers are often limited to two-dimensional, small working spaces, while heterogeneous swimmers can only be controlled in small numbers without the option for collective control. In this study, we present a purely magnetic control methodology for the selective-scalable locomotion of helical magnetic swimmers within confined channels. By employing a unique gradient field distribution, referred to as the "selection field," along with space-uniform rotating fields, we establish a "selection volume" that allows swimmers within it to fully rotate, while those outside remain stationary. We explore various conditions of the selection volume to analyze the locomotion dynamics of the swimmers in relation to the position of the selection volume. Experimental results demonstrate the selective-scalable locomotion of identical robots, ranging from one to an arbitrary number (N) of robots, as well as their selective-individual manipulation for multitasking applications. Furthermore, compatibility of the proposed method with different magnetic torque-driven robots is exemplified through the selective control of rolling robots. Moreover, three-dimensional selective-scalable control is also demonstrated for four swimmers in a quasi-three-dimensional channel, as well as for two swimmers within a true three-dimensional channel.

Highly Shape-Adaptable Honeycomb Gripper Using Orthotropic Surface Tension

Astrictive-type grippers, which generate gripping forces from adhesive forces at the contact surface such as suction cup, are popular end-effectors as picking solutions because of their simplicity and small working space. However, the adhesive force of the astrictive gripper decreases with increasing complexity of the object surface; thus, its application has been restricted to simple picking of objects with a flat surface. Here, we present an all-round honeycomb astrictive gripper that has an orthotropic surface tension for grasping highly irregular shaped objects with an uneven surface. The design is inspired by mimicking the two-level (macro- and meso-scale) shape adaptation of the octopus's leg. The stiffness-variable structure is also consisted to change its stiffness similar to the function of octopus's leg, and owing to the combination of these structures makes possible to perform various tasks including hammering, breakfast serving, and vaccination which were not possible for previous astrictive gripper.

Evaluation of skill acquisition characteristics depending on the size of a dry box

Background Few studies have analyzed the effect of the size of the working space in training on the acquisition of endoscopic skills. In this study, adult- and infant-sized dry boxes (DBs) were used to verify how the size of the working space in training affects forceps manipulation and learning curve. Material and methods Seventy-two medical students were enrolled. The task was peg transfer. The training environment was divided into adult- and infant-sized DBs. Skill evaluations were also divided into adult- and infant-sized DBs (four groups in total). The forceps manipulation characteristics and task completion time were compared before and after training. Results Regarding skill evaluations using adult-sized DBs, there were no significant differences between the infant- and adult-sized DB-trained groups. Regarding skill evaluations using infant-sized DBs, there were no significant differences between the groups before training. After training, there was no significant difference in the total path length or average acceleration of the forceps between the groups. However, the infant-sized DB-trained group had a significantly faster average forceps velocity and faster task completion time than the adult-sized DB-trained group. Conclusion Training with a small DB is more efficient in acquiring smoother and faster forceps manipulation in a small working space.

Drive Layout Configuration Strategy and Scale Optimization Design of Multi-Drive Mode Parallel Mechanism

Abstract Aiming at the inherent defects of single-drive mode parallel mechanisms, such as small good workspace and many singular configurations, a new multi-drive mode parallel mechanism is proposed from the perspective of driving innovation. Taking the planar 6R parallel mechanism as an example, the driving layout configuration strategy and scale optimization design are studied. First, the potential driving layout of the mechanism is analyzed, and the inverse kinematics model of the mechanism is established. Then, based on the motion/force transmission index, the singular space and good transmission workspace of the mechanism are identified, and the mechanism-driven layout configuration strategy is formulated to complete the performance comparison analysis. Finally, based on the performance map method, the scale optimization design of the mechanism is carried out, the prototype is developed and manufactured, and the experimental verification is carried out. The research results show that the multi-drive mode parallel mechanism can improve its kinematic performance without changing the topological structure and scale parameters of the mechanism.

Design and Analysis of a Novel Redundant Parallel Mechanism for Long Bone Fracture Reduction

Abstract In recent years, parallel robots have become a hot research topic in trauma fracture treatment because of their high precision, high load capacity, and compact structure. However, compared with serial robots, parallel robots have disadvantages like smaller workspaces and more complex dexterity. In this paper, a novel redundant parallel mechanism (RPM) for long bone fracture reduction is proposed based on Stewart parallel mechanism (SPM). 6 kinematically redundant DOFs (Degrees of freedom) are added to the RPM. First, the kinematics of the RPM is established, and its workspace is calculated. The analysis results indicate that the position workspace of the RPM is about 19 times larger than that of the SPM. The RPM has a similar range of torsion angles as the SPM, but a more extensive range of tilt angles than the SPM. Second, the singularities of the two parallel mechanisms are compared based on the dimensionally homogeneous Jacobian matrix. The results show that the dexterity of the RPM is much better than the SPM. Third, a multi-parameter multi-objective optimization method is proposed to optimize the geometry parameters of the RPM. The statics of the RPM is analyzed by finite element analysis. To further expand the performance of the RPM, the unfixed RPM (URPM) is proposed. The analysis results show that the URPM is superior to the RPM in terms of workspace and dexterity. Finally, experiments are conducted to verify the effectiveness of the proposed methods in this paper.

Depth-Dependent Control in Vision-Sensor Space for Reconfigurable Parallel Manipulators.

In this paper, a control approach for reconfigurable parallel robots is designed. Based on it, controls in the vision-sensor, 3D and joint spaces are designed and implemented in target tracking tasks in a novel reconfigurable delta-type parallel robot. No a priori information about the target trajectory is required. Robot reconfiguration can be used to overcome some of the limitations of parallel robots like small relative workspace or multiple singularities, at the cost of increasing the complexity of the manipulator, making its control design even more challenging. No general control methodology exists for reconfigurable parallel robots. Tracking objects with unknown trajectories is a challenging task required in many applications. Sensor-based robot control has been actively used for this type of task. However, it cannot be straightforwardly extended to reconfigurable parallel manipulators. The developed vision-sensor space control is inspired by, and can be seen as an extension of, the Velocity Linear Camera Model-Camera Space Manipulation (VLCM-CSM) methodology. Several experiments were carried out on a reconfigurable delta-type parallel robot. An average positioning error of 0.6 mm was obtained for static objectives. Tracking errors of 2.5 mm, 3.9 mm and 11.5 mm were obtained for targets moving along a linear trajectory at speeds of 6.5, 9.3 and 12.7 cm/s, respectively. The control cycle time was 16 ms. These results validate the proposed approach and improve upon previous works for non-reconfigurable robots.

Knowledge, Attitude, and Practice Regarding the Prevalence of Occupation Related Musculoskeletal Disorders and Ergonomics among Dental Practitioners in a Tertiary Care Hospital in Karachi, Cross Sectional Survey

Introduction: The precise, minute nature of dental treatments renders a dentist particularly sensitive to ergonomic-driven hazards. Ergonomics is the study of adapting the work environment to the worker for maximum efficiency and safety. There are many contributing factors that may result in multiple occupational hazards for dentists, including inappropriate working hours, odd postures, poor ergonomics practice, a small workspace with restricted movement, and prolonged standing, which can overstretch the cervical spine and lumbar region and cause other MSDs like damage to the muscles, joints, bones, ligaments, tendons, nerves, and blood vessels. Methods and Materials: A cross sectional survey was conducted in a private tertiary care hospital. A closed ended questionnaire with informed consent will be distributed to the participants. Results: According to specialty 77.8% were general practitioner, 8.2% were maxillofacial specialist, 3.5% were specialist in restorative dentistry, 2.9% were Periodontist and orthodontist followed by 1.2% with Endodontist and Paedodontist. Conclusion: Effective ergonomics application can reduce the risk of strenuous injuries by enhancing the working environment; nevertheless, ineffective ergonomics application can result in a variety of health risks that could eventually cause disability that ends a career. For dental professionals to successfully care for patients and concentrate on their work, we need to develop primary and secondary prevention methods to reduce the prevalence of work-related MSDs among them.

Stapleless thoracoscopic lobectomy for congenital pulmonary airway malformation: a simple technique in thoracoscopic surgery.

Congenital pulmonary airway malformation (CPAM) is a developmental malformation that affects the lung parenchyma, especially terminal respiratory bronchioles. This paper reports a case of an infant diagnosed with CPAM who underwent stapleless thoracoscopic lobectomy using Hem-o-Lok clips®. Computed tomography showed cystic pulmonary lesions in the left lower lobe. Thoracoscopic lobectomy was performed at the age of 1year and 3months. During surgery, the hilar vasculature was treated using either Hem-o-Lok® clips or a LigaSure vessel sealing system. The lower lobe bronchus was divided using double Hem-o-Lok® clips proximally. The surgery was successfully completed. The patient's postoperative course was uneventful, and there were no complications. This technique can be easily performed as a thoracoscopic lobectomy with the potential benefits of safe and effective procedures for bronchus closure and vascular sealing in the small working space of pediatric patients.

Line Follower and Bluetooth Controlled Robot

Abstract: Our proposal is a vehicle that can follow a straight path. It can follow a line until it reaches the end of the line and then pause until the return instruction is issued. This can be used to convey items from a car to a destination (at the end of the line) within a house or small work space. Another advantage of the project is that it can be controlled via Bluetooth. A car is a differential wheeled vehicle, which is a mobile vehicle with two independently powered wheels on either side of the vehicle body. To operate the automobile through bluetooth, a mobile application for the joystick was downloaded. We may choose whether the car should act as a line follower or Bluetooth via the application

V04-07 ROBOTIC ASSISTED SIDE-TO-SIDE REFLUXING NON-DISMEMBERED URETEROCYSTOTOMY FOR MANAGEMENT OF AN OBSTRUCTED MEGAURETER

You have accessJournal of UrologyCME1 Apr 2023V04-07 ROBOTIC ASSISTED SIDE-TO-SIDE REFLUXING NON-DISMEMBERED URETEROCYSTOTOMY FOR MANAGEMENT OF AN OBSTRUCTED MEGAURETER Hailey Silverii, Xinyuan Zhang, and Nicolas Fernandez Hailey SilveriiHailey Silverii More articles by this author , Xinyuan ZhangXinyuan Zhang More articles by this author , and Nicolas FernandezNicolas Fernandez More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003252.07AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Obstructed megaureters can often be safely observed; however, when there are associated changes in renal function or recurrent infections, surgical intervention is indicated. Surgical management options include: endoscopic intervention, diversion with cutaneous ureterostomy, non-refluxing ureteral reimplantation, or refluxing ureteral reimplantation with an end-to-side or side-to-side approach. Determining factors for management include the circumstance for which intervention is indicated, age and size of the patient, degree of ureteral dilation and obstruction, and bladder size. In this video, we present a robotic assisted side-to-side refluxing non-dismembered ureterocystotomy for an infant with a ureterovesical junction (UVJ) obstruction. METHODS: A 4-month-old, 6.6 kg male with a history of antenatally diagnosed hydroureteronephrosis presents with a 3 month interval renal ultrasound demonstrating worsened degree of right hydroureteronephrosis with debris and increased parenchymal thinning. He has no prior history of urinary tract infections. A MAG3 renal scan demonstrated normal differential function and an obstruction at the level of the right UVJ. Given the patient’s young age and small bladder capacity, a non-refluxing ureteral reimplantation was not felt to be a feasible option. A side-to-side ureterocystotomy was recommended to which the family consented. After further counseling, a robotic approach was agreed upon and completed with the assistance of the Da Vinci XI platform (Intuitive Surgical, Sunnyvale, CA). RESULTS: The case began with a cystoscopy and right retrograde pyelogram which confirmed the level of the obstruction at the UVJ. Three supraumbilical 8 mm ports were placed prior to docking the Da Vinci system. Console time was 60 minutes. The tension free side-to-side anastomosis was completed in an interrupted fashion between the bladder and the dilated distal ureter. Estimated blood loss was less than 5 cc. The patient was discharged on post-operative day one after Foley catheter removal and the patient is doing very well. CONCLUSIONS: In conclusion, a robotic approach to a refluxing non-dismembered ureterocystotomy can safely be employed in small infants with adaptations in port placement, dissection, and anastomosis given small working space and risk to injuring nearby structures. Source of Funding: N/A © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e340 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Hailey Silverii More articles by this author Xinyuan Zhang More articles by this author Nicolas Fernandez More articles by this author Expand All Advertisement PDF downloadLoading ...

Haptify: A Measurement-Based Benchmarking System for Grounded Force-Feedback Devices

Grounded force-feedback (GFF) devices are an established and diverse class of haptic technology based on robotic arms. However, the number of designs and how they are specified make comparing devices difficult. We thus present Haptify, a benchmarking system that can thoroughly, fairly, and noninvasively evaluate GFF haptic devices. The user holds the instrumented device end-effector and moves it through a series of passive and active experiments. Haptify records the interaction between the hand, device, and ground with a seven-camera optical motion-capture system, a 60-cm-square custom force plate, and a customized sensing end-effector. We demonstrate six key ways to assess GFF device performance: workspace shape, global free-space forces, global free-space vibrations, local dynamic forces and torques, frictionless surface rendering, and stiffness rendering. We then use Haptify to benchmark two commercial haptic devices. With a smaller workspace than the 3D Systems Touch, the more expensive Touch X outputs smaller free-space forces and vibrations, smaller and more predictable dynamic forces and torques, and higher-quality renderings of a frictionless surface and high stiffness.

Design, Analysis, and Optimization of a Kinematically Redundant Parallel Robot

It has been nearly 60 years since the introduction of the Gough–Stewart manipulator (GSM). With the advantages of superior load capacity and high precision, the GSM still plays an important role in many fields. However, the GSM has limitations such as a small workspace and complex singularities. To overcome these problems, a novel kinematically redundant parallel robot is designed with three redundant actuators added on the basis of the GSM. First, the structure of the proposed robot is introduced, and the kinematics of the proposed robot is established. Second, the workspaces of the proposed robot are analyzed, and the results show that the position workspace volume and the maximum torsion and orientation angles of the proposed robot can be improved effectively. Third, the singularities of the proposed robot and the GSM are compared based on the Jacobian matrices. Finally, the multi-parameter, multi-objective optimization is used to optimize the geometric parameters of the proposed robot, and an experimental prototype of the proposed robot is designed based on the optimization results.

3-PRRR parallel mechanism kinematics and workspace analysis

Aiming at the current problems of small working space and the high cost of erection of parallel structure FDM-3D printer, a 3-PRRR parallel mechanism with a common line of branch chain moving sub is proposed and planned to be used in 3D printing equipment. First, the degrees of freedom of the 3-PRRR parallel mechanism is analyzed based on the spiral theory, and the positive and negative solutions of the position of the mechanism are established by the vector method; on this basis, the working space of the mechanism is analyzed using the Monte Carlo method; finally, the mechanism is specifically applied to the FDM- 3D printing device.