An Open-Source Research Kit for the da Vinci ® Surgical System

Abstract-We present a telerobotics research platform that provides complete access to all levels of control via opensource electronics and software. The electronics employs an FPGA to enable a centralized computation and distributed I/O architecture in which all control computations are implemented in a familiar development environment (Linux PC) and lowlatency I/O is performed over an IEEE-1394a (FireWire) bus at speeds up to 400 Mbits/sec. The mechanical components are obtained from retired first-generation da Vinci R Surgical Systems. This system is currently installed at 11 research institutions, with additional installations underway, thereby creating a research community around a common open-source hardware and software platform

A Prospective Multicenter Study Evaluating Learning Curves and Competence in Endoscopic Ultrasound and Endoscopic Retrograde Cholangiopancreatography Among Advanced Endoscopy Trainees: The Rapid Assessment of Trainee Endoscopy Skills (RATES) Study

Background and aims Based on the Next Accreditation System, trainee assessment should occur on a continuous basis with individualized feedback. We aimed to validate endoscopic ultrasound (EUS) and endoscopic retrograde cholangiopancreatography (ERCP) learning curves among advanced endoscopy trainees (AETs) using a large national sample of training programs and to develop a centralized database that allows assessment of performance in relation to peers. Methods ASGE recognized training programs were invited to participate and AETs were graded on ERCP and EUS exams using a validated competency assessment tool that assesses technical and cognitive competence in a continuous fashion. Grading for each skill was done using a 4-point scoring system and a comprehensive data collection and reporting system was built to create learning curves using cumulative sum analysis. Individual results and benchmarking to peers were shared with AETs and trainers quarterly. Results Of the 62 programs invited, 20 programs and 22 AETs participated in this study. At the end of training, median number of EUS and ERCP performed/AET was 300 (range 155-650) and 350 (125-500). Overall, 3786 exams were graded (EUS:1137; ERCP–biliary 2280, pancreatic 369). Learning curves for individual endpoints, and overall technical/cognitive aspects in EUS and ERCP demonstrated substantial variability and were successfully shared with all programs. The majority of trainees achieved overall technical (EUS: 82%; ERCP: 60%) and cognitive (EUS: 76%; ERCP: 100%) competence at conclusion of training. Conclusions These results demonstrate the feasibility of establishing a centralized database to report individualized learning curves and confirm the substantial variability in time to achieve competence among AETs in EUS and ERCP

Competence in Endoscopic Ultrasound and Endoscopic Retrograde Cholangiopancreatography, From Training Through Independent Practice.

BACKGROUND & AIMS: It is unclear whether participation in competency-based fellowship programs for endoscopic ultrasound (EUS) and endoscopic retrograde cholangiopancreatography (ERCP) results in high-quality care in independent practice. We measured quality indicator (QI) adherence during the first year of independent practice among physicians who completed endoscopic training with a systematic assessment of competence. METHODS: We performed a prospective multicenter cohort study of invited participants from 62 training programs. In phase 1, 24 advanced endoscopy trainees (AETs), from 20 programs, were assessed using a validated competence assessment tool. We used a comprehensive data collection and reporting system to create learning curves using cumulative sum analysis that were shared with AETs and trainers quarterly. In phase 2, participating AETs entered data into a database pertaining to every EUS and ERCP examination during their first year of independent practice, anchored by key QIs. RESULTS: By the end of training, most AETs had achieved overall technical competence (EUS 91.7%, ERCP 73.9%) and cognitive competence (EUS 91.7%, ERCP 94.1%). In phase 2 of the study, 22 AETs (91.6%) participated and completed a median of 136 EUS examinations per AET and 116 ERCP examinations per AET. Most AETs met the performance thresholds for QIs in EUS (including 94.4% diagnostic rate of adequate samples and 83.8% diagnostic yield of malignancy in pancreatic masses) and ERCP (94.9% overall cannulation rate). CONCLUSIONS: In this prospective multicenter study, we found that although competence cannot be confirmed for all AETs at the end of training, most meet QI thresholds for EUS and ERCP at the end of their first year of independent practice. This finding affirms the effectiveness of training programs. Clinicaltrials.gov ID NCT02509416

Competence in Endoscopic Ultrasound and Endoscopic Retrograde Cholangiopancreatography, From Training Through Independent Practice.

BACKGROUND & AIMS: It is unclear whether participation in competency-based fellowship programs for endoscopic ultrasound (EUS) and endoscopic retrograde cholangiopancreatography (ERCP) results in high-quality care in independent practice. We measured quality indicator (QI) adherence during the first year of independent practice among physicians who completed endoscopic training with a systematic assessment of competence. METHODS: We performed a prospective multicenter cohort study of invited participants from 62 training programs. In phase 1, 24 advanced endoscopy trainees (AETs), from 20 programs, were assessed using a validated competence assessment tool. We used a comprehensive data collection and reporting system to create learning curves using cumulative sum analysis that were shared with AETs and trainers quarterly. In phase 2, participating AETs entered data into a database pertaining to every EUS and ERCP examination during their first year of independent practice, anchored by key QIs. RESULTS: By the end of training, most AETs had achieved overall technical competence (EUS 91.7%, ERCP 73.9%) and cognitive competence (EUS 91.7%, ERCP 94.1%). In phase 2 of the study, 22 AETs (91.6%) participated and completed a median of 136 EUS examinations per AET and 116 ERCP examinations per AET. Most AETs met the performance thresholds for QIs in EUS (including 94.4% diagnostic rate of adequate samples and 83.8% diagnostic yield of malignancy in pancreatic masses) and ERCP (94.9% overall cannulation rate). CONCLUSIONS: In this prospective multicenter study, we found that although competence cannot be confirmed for all AETs at the end of training, most meet QI thresholds for EUS and ERCP at the end of their first year of independent practice. This finding affirms the effectiveness of training programs. Clinicaltrials.gov ID NCT02509416

Modelling, simulation and planning of needle motion in soft tissues

Precise needle placement is required for the success of a wide variety of percutaneous interventions in medicine. Insertions into soft tissues can be difficult to learn and to perform, due to tissue deformation, needle deflection and limited visual feedback. Little quantitative information is known about the interaction between needles and soft tissues during puncture, and no effective physically-based training, planning and guidance systems exist for such procedures. This work aims to characterise needle-tissue interaction by measuring contact forces and deformations that are applied during insertions into soft tissue phantoms. A new methodology for estimating the forces that occur along the needle shaft during insertion is described. The approach is based on physical experiments, as well as on linear elastic phantom models that are discretised by traditional Finite Element Methods. Shaft force distributions are derived from insertions into homogeneous and simple layered inhomogeneous tissue phantoms at several driving velocities, and are applied as boundary conditions to tissue models for physically-based simulations of needle insertion trajectories. A large-strain elastic needle model is coupled to the tissue models to account for needle deflection and bending during simulated insertion. Since the force-displacement relationship is only of interest along the needle shaft, a condensation technique is shown to reduce the computational complexity of linear simulation models significantly. The boundary conditions that determine the tissue and needle motion change as the needle penetrates, or is withdrawn from the tissue model. Boundary condition and local material coordinate changes are facilitated by fast low-rank matrix updates. Such numerical schemes have been seen in prior work involving point and surface interaction; however, in this work the condensation state, boundary conditions and material coordinates evolve as the needle penetrates the tissue volume, and as internal contact states change. These novel interactive simulation techniques allow users to manipulate a three-degree-of-freedom virtual needle as it penetrates virtual tissue models, while experiencing steering torques and forces through a planar haptic interface. Models and simulations are also used to formulate needle insertion as a trajectory planning and control problem. The concept of needle steering is developed, and a Needle Manipulation Jacobian is defined to express the relationship between the needle base and tip velocities. This concept is used in conjunction with a potential-field-based path planning technique to demonstrate needle tip placement and obstacle avoidance. Results from open loop insertion experiments are also provided.Applied Science, Faculty ofElectrical and Computer Engineering, Department ofGraduat

Position and force trajectory programming within a virtual excavation environment

A means of automatically reproducing operator demonstrated excavation trajectories has been developed for the automation of repetitive digging tasks and the teleoperation of remote machines. The dynamic adjustment of backhoe end-effector impedance, according to a variable impedance-control strategy, has been proposed for this purpose. This strategy matches machine end-point and environment impedances by means of a new, generalised duality principle which enables simultaneous position and force control over varying environment characteristics, by observing a specified compromise between position and force trajectory errors. A virtual excavation environment has been designed and implemented to provide an inexpensive, safe, flexible, yet realistic platform for the development and evaluation of such automation and control strategies. The simulator comprises a mechanical impedance model of the excavator manipulator, a model for the synthesis of bucket-ground interaction forces, as well as graphical and haptic interfaces for both visual and force feedback. Experimental results show that task demonstration and playback within a virtual excavation environment results in appropriate trajectory tracking throughout a digging motion which encounters environment impedances ranging from free motion to hard contact.Applied Science, Faculty ofElectrical and Computer Engineering, Department ofGraduat

Modeling simulation and planning of needle motion in soft tissues

Precise needle placement is required for the success of a wide variety of percutaneous interventions in medicine. Insertions into soft tissues can be difficult to learn and to perform, due to tissue deformation, needle deflection and limited visual feedback. Little quantitative information is known about the interaction between needles and soft tissues during puncture, and no effective physicallybased training, planning and guidance systems exist for such procedures. This work aims to characterise needle-tissue interaction by measuring contact forces and deformations that are applied during insertions into soft tissue phantoms. A new methodology for estimating the forces that occur along the needle shaft during insertion is described. The approach is based on physical experiments, as well as on linear elastic phantom models that are discretised by traditional Finite Element Methods. Shaft force distributions are derived from insertions into homogeneous and simple layered inhomogeneous tissue phantoms at several driving velocities, and are applied as boundary conditions to tissue models for physically-based simulations of needle insertion trajectories. A large-strain elastic needle model is coupled to the tissue models to account for needle deflection and bending during simulated insertion. Sinc

Robotic assistant for transperineal prostate interventions

Abstract. Numerous studies have demonstrated the efficacy of imageguided needle-based therapy and biopsy in the management of prostate cancer. The accuracy of traditional prostate interventions performed using transrectal ultrasound (TRUS) is limited by image fidelity, needle template guides, needle deflection and tissue deformation. Magnetic Resonance Imaging (MRI) is an ideal modality for guiding and monitoring such interventions due to its excellent visualization of the prostate, its sub-structure and surrounding tissues. We have designed a comprehensive robotic assistant system that allows prostate biopsy and brachytherapy procedures to be performed entirely inside a 3T closed MRI scanner. We present a detailed design of the robotic manipulator and an evaluation of its usability and MR compatibility

Integrated System for Robot-Assisted in Prostate Biopsy in Closed MRI Scanner

Abstract-Prostate cancer biopsy is a routine medical procedure, yet conventional techniques suffer from low sensitivity attributed to suboptimal image guidance and needle placement. Targeting small lesions and foci (5 mm in diameter) is particularly prone to errors. We developed an integrated system to perform robot-assisted transperineal needle insertions into the prostate, under Magnetic Resonance Imaging (MRI) guidance. The system provides arbitrary needle trajectories and allows for simultaneous surveillance and correction of the needle path, based on intra-operative MRI. System functionality and data transfer and processing tests were conducted. Five lesions embedded in the gel phantom were targeted successfully, while communication delays (due to higher image frame rates) had no adverse affect on robot-software communication. The system was sufficiently resistant to high network loads and performed with an acceptable transfer rate