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This paper describes a new implementation for calculating Jacobian and its time derivative for robot manipulators in real-time. The estimation of Jacobian is the key in the real-time implementation of kinematics and dynamics of complex planar or spatial robots with fixed as well as floating axes in which the Jacobian form changes with the structure. The proposed method is suitable for such implementations. The new method is based on matrix differential calculus. Unlike the conventional methods, which are based on screw theory, the Jacobian calculation in the proposed approach has been reduced to the inner product of two matrices. Use of the new method to derive linear and angular velocity parts of Jacobian and its time derivative is described in detail. We have demonstrated the method using a two-DOF spatial robot and a hyper-redundant spatial robot., Competing Interests: The authors have declared that no competing interests exist.

Objective: Inadequate visual and force feedback while navigating surgical tools elevate the risk of endovascular procedures. It also poses occupational hazard due to repeated exposure to X-rays. A teleoperated robotic system that augments surgeon's actions is a solution., Method: We have designed and developed an endovascular robotic system that augments surgeon's actions using conventional surgical tools, as well as generates feedback in order to ensure safety during the procedure. The reaction force from vasculature is estimated from motor current that drives the surgical tool. Calibration required for force estimation is based on bilevel optimization. Input shaping is used in conjunction with a cascaded controller to avoid large responses due to faster inputs and to track tool position. The design, realization, and testing of our system are presented., Results: The responses of the system in comparison with the dynamics model is similar vis-à-vis the same input commands. Any error in the position tracking is reduced by the cascaded controller. Phase-portrait analysis of the system showed that the system is stable. The reaction force estimation is validated against load cell measurements. The safety mechanism in the events of excessive reaction forces while interacting with vasculature is demonstrated., Conclusion and Significance: Our system is a step toward intelligent robots that can assist surgeons during endovascular procedures by monitoring and alerting the surgeons regarding detrimental parameters. It arrests any unintended excursions of the surgical tools or surgeon's actions. This will also eliminate the need for surgeons to be in radiation environment.

Surgeons typically rely on their past training and experiences as well as visual aids from medical imaging techniques such as magnetic resonance imaging (MRI) or computed tomography (CT) for the planning of surgical processes. Often, due to the anatomical complexity of the surgery site, two dimensional or virtual images are not sufficient to successfully convey the structural details. For such scenarios, a 3D printed model of the patient's anatomy enables personalized preoperative planning. This paper reviews critical aspects of 3D printing for preoperative planning and surgical training, starting with an overview of the process-flow and 3D printing techniques, followed by their applications spanning across multiple organ systems in the human body. State of the art in these technologies are described along with a discussion of current limitations and future opportunities.

We present a new surgical robot hardware-in-the-loop simulator, with 3D surgical field reconstruction in RGB-D sensor range, which allows tool-tissue interactions to be presented as haptic feedback and thus provides the situation awareness of unwanted collision. First, the point cloud of the complete surgical environment is constructed from multiple frames of sensor data to avoid the occlusion issue. Then the user selects a region of interest where the robot's tool must avoid (also called forbidden region). The real-time haptic force rendering algorithm computes the interaction force which is then communicated to a haptic device at 1 kHz, to assist the surgeon to perform safe actions. The robot used is a RAVEN II system, RGB-D sensor is used to scan the environment, and two Omni haptic devices provide the 3-DoF haptic force. A registration pipeline is presented to complete the surgical environment point cloud mapping in preoperative surgery planning phase, which improves quality of haptic rendering in the presence of occlusion. Furthermore, we propose a feasible and fast algorithm which extends the existing work on the proxy-based method for haptic rendering between a Haptic Interaction Point (HIP) and a point cloud. The proposed methodology has the potential of improving the safety of surgical robots.

This work presents a software and hardware framework for a telerobotic surgery safety and motor skill training simulator. The aims are at providing trainees a comprehensive simulator for acquiring essential skills to perform telerobotic surgery. Existing commercial robotic surgery simulators lack features for safety training and optimal motion planning, which are critical factors in ensuring patient safety and efficiency in operation. In this work, we propose a hardware-in-the-loop simulator directly introducing these two features. The proposed simulator is built upon the Raven-II™ open source surgical robot, integrated with a physics engine and a safety hazard injection engine. Also, a Fast Marching Tree-based motion planning algorithm is used to help trainee learn the optimal instrument motion patterns. The main contributions of this work are (1) reproducing safety hazards events, related to da Vinci™ system, reported to the FDA MAUDE database, with a novel haptic feedback strategy to provide feedback to the operator when the underlying dynamics differ from the real robot's states so that the operator will be aware and can mitigate the negative impact of the safety-critical events, and (2) using motion planner to generate semioptimal path in an interactive robotic surgery training environment.

Objective: To validate robot-assisted surgery skills acquisition using an augmented reality (AR)-based module for urethrovesical anastomosis (UVA)., Methods: Participants at three institutions were randomised to a Hands-on Surgical Training (HoST) technology group or a control group. The HoST group was given procedure-based training for UVA within the haptic-enabled AR-based HoST environment. The control group did not receive any training. After completing the task, the control group was offered to cross over to the HoST group (cross-over group). A questionnaire administered after HoST determined the feasibility and acceptability of the technology. Performance of UVA using an inanimate model on the daVinci Surgical System (Intuitive Surgical Inc., Sunnyvale, CA, USA) was assessed using a UVA evaluation score and a Global Evaluative Assessment of Robotic Skills (GEARS) score. Participants completed the National Aeronautics and Space Administration Task Load Index (NASA TLX) questionnaire for cognitive assessment, as outcome measures. A Wilcoxon rank-sum test was used to compare outcomes among the groups (HoST group vs control group and control group vs cross-over group)., Results: A total of 52 individuals participated in the study. UVA evaluation scores showed significant differences in needle driving (3.0 vs 2.3; P = 0.042), needle positioning (3.0 vs 2.4; P = 0.033) and suture placement (3.4 vs 2.6; P = 0.014) in the HoST vs the control group. The HoST group obtained significantly higher scores (14.4 vs 11.9; P 0.012) on the GEARS. The NASA TLX indicated lower temporal demand and effort in the HoST group (5.9 vs 9.3; P = 0.001 and 5.8 vs 11.9; P = 0.035, respectively). In all, 70% of participants found that HoST was similar to the real surgical procedure, and 75% believed that HoST could improve confidence for carrying out the real intervention., Conclusion: Training in UVA in an AR environment improves technical skill acquisition with minimal cognitive demand., (© 2014 The Authors. BJU International © 2014 BJU International.)

Background: Recent incorporation of simulation in surgical training necessitates developing validated platforms for training and assessment. A tool should fulfill the fundamental criteria of validation., Objective: To report the ability of a simulation-based robotic training curriculum-Fundamental Skills of Robotic Surgery (FSRS)-to assess and distinguish between different performance levels of operator experience (construct validity)., Materials and Methods: This is a prospective multicenter observational study. Participants were classified as novice (0 robotic cases performed) and experts (>150 robotic cases performed). All participants were required to complete 4 key tasks in a previously validated FSRS curriculum: ball placement, coordinated tool control, fourth arm control, and needle handling and exchange. Using the metrics available in the simulator software, the performances of each group were compared to evaluate construct validation., Results: A convenience cohort of 61 surgeons participated. Novice group (n = 49) consisted of 41 fellows/residents/medical students and 8 trained open/laparoscopic surgeons, whereas expert group consisted of 12 surgeons. The novice group had no previous robotic console experience, whereas the expert group had >150 prior robotic cases experience. An overall significant difference was observed in favor of the expert group in 4 skill sets (p < 0.05). Time to complete all 4 tasks was significantly shorter in the expert group (p < 0.001). The expert group displayed significantly lesser tool collision (p = 0.002) and reduced tissue damage (p < 0.001). In performing most tasks, the expert group's camera (p < 0.001) and clutch usage (p < 0.001) was significantly greater when compared with the novice group., Conclusion: The components of the FSRS curriculum showed construct validity. This validation would help in effectively implementing this curriculum for robot-assisted surgical training., (© 2014 Published by Association of Program Directors in Surgery on behalf of Association of Program Directors in Surgery.)

Background: A standardized scoring system does not exist in virtual reality-based assessment metrics to describe safe and crucial surgical skills in robot-assisted surgery. This study aims to develop an assessment score along with its construct validation., Materials and Methods: All subjects performed key tasks on previously validated Fundamental Skills of Robotic Surgery curriculum, which were recorded, and metrics were stored. After an expert consensus for the purpose of content validation (Delphi), critical safety determining procedural steps were identified from the Fundamental Skills of Robotic Surgery curriculum and a hierarchical task decomposition of multiple parameters using a variety of metrics was used to develop Robotic Skills Assessment Score (RSA-Score). Robotic Skills Assessment mainly focuses on safety in operative field, critical error, economy, bimanual dexterity, and time. Following, the RSA-Score was further evaluated for construct validation and feasibility. Spearman correlation tests performed between tasks using the RSA-Scores indicate no cross correlation. Wilcoxon rank sum tests were performed between the two groups., Results: The proposed RSA-Score was evaluated on non-robotic surgeons (n = 15) and on expert-robotic surgeons (n = 12). The expert group demonstrated significantly better performance on all four tasks in comparison to the novice group. Validation of the RSA-Score in this study was carried out on the Robotic Surgical Simulator., Conclusion: The RSA-Score is a valid scoring system that could be incorporated in any virtual reality-based surgical simulator to achieve standardized assessment of fundamental surgical tents during robot-assisted surgery., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Objective: To develop and establish effectiveness of simulation-based robotic curriculum--fundamental skills of robotic surgery (FSRS)., Methods: FSRS curriculum was developed and incorporated into a virtual reality simulator, Robotic Surgical Simulator (RoSS). Fifty-three participants were randomized into an experimental group (EG) or control group (CG). The EG was asked to complete the FSRS and 1 final test on the da Vinci Surgical System (dVSS). The dVSS test consisted of 3 tasks: ball placement, suture pass, and fourth arm manipulation. The CG was directly tested on the dVSS then offered the chance to complete the FSRS and re-tested on the dVSS as a crossover (CO) group., Results: Sixty-five percent of participants had never formally trained using laparoscopic surgery. Ball placement: the EG demonstrated shorter time (142 vs 164 seconds, P = .134) and more precise (1.5 vs 2.5 drops, P = .014). The CO took less time (P <.001) with greater precision (P <.001). Instruments were rarely lost from the field. Suture pass: the EG demonstrated better camera utilization (4.3 vs 3.0, P = .078). Less instrument loss occurred (0.5 vs 1.1, P = .026). Proper camera usage significantly improved (P = .009). Fourth arm manipulation: the EG took less time (132 vs 157 seconds, P = .302). Meanwhile, loss of instruments was less frequent (0.2 vs 0.8, P = .076). Precision in the CO improved significantly (P = .042) and camera control and safe instrument manipulation showed improvement (1.5 vs 3.5, 0.2 vs 0.9, respectively)., Conclusion: FSRS curriculum is a valid, feasible, and structured curriculum that demonstrates its effectiveness by significant improvements in basic robotic surgery skills., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Objective: To determine the overall cost effectiveness of surgical skills training on Robotic Surgical Simulator (RoSS)., Methods: This study evaluates the cost analysis of utilizing RoSS for robot-assisted surgical training, at Roswell Park Center for Robotic Surgery. Trainees were queried for time spent on the RoSS console over a period of 1 year, starting from June 2010 to June 2011. Time spent was converted to training time consumed on robotic console, resulting in loss of OR time and revenue. The mechanical durability of the RoSS was also determined., Results: 105 trainees spent 361 h on the RoSS. This duration converted to 73 robot-assisted radical prostatectomy cases, and 72 animal lab sessions. RoSS prevented a potential loss of $600,000, while 72 animal labs would have cost more than $72,000 without including initial robot installation, annual maintenance and personnel expenses. The mechanical durability testing determined breakdown at 180 and 360 h for master control and pinch device, which were repaired under warranty., Conclusion: RoSS is a cost effective surgical simulator for implementation of a simulation-based robot-assisted surgical training program., (Copyright © 2013 Surgical Associates Ltd. Published by Elsevier Ltd. All rights reserved.)

Objective: • To assess the content validity of an early prototype robotic simulator. Minimally invasive surgery poses challenges for training future surgeons. The Robotic Surgical Simulator (RoSS) is a novel virtual reality simulator for the da Vinci Surgical System., Patients and Methods: • Participants attending the 2010 International Robotic Urology Symposium were invited to experience RoSS. Afterwards, participants completed a survey regarding the appropriateness of the simulator as a teaching tool., Results: • Forty-two subjects including surgeons experienced with robotics (n= 31) and novices (n= 11) participated in this study. • Eighty per cent of the entire cohort had an average of 4 years of experience with robot-assisted surgery. • Eleven (26%) novices lacked independent robot-assisted experience. The expert group comprised 17 (41%) surgeons averaging 881 (160-2200) robot-assisted cases. Experts rated the 'clutch control' virtual simulation task as a good (71%) or excellent (29%) teaching tool. • Seventy-eight per cent rated the 'ball place' task as good or excellent but 22% rated it as poor. • Twenty-seven per cent rated the 'needle removal' task as an excellent teaching tool, 60% rated it good and 13% rated it poor. • Ninety-one per cent rated the 'fourth arm tissue removal' task as good or excellent. • Ninety-four per cent responded that RoSS would be useful for training purposes. • Eighty-eight per cent felt that RoSS would be an appropriate training and testing format before operating room experience for residents. • Seventy-nine per cent indicated that RoSS could be used for privileging or certifying in robotic surgery., Conclusion: • Results based on expert evaluation of RoSS as a teaching modality illustrate that RoSS has appropriate content validity., (© 2010 THE AUTHORS. BJU INTERNATIONAL © 2010 BJU INTERNATIONAL.)

Recent growth of daVinci Robotic Surgical System as a minimally invasive surgery tool has led to a call for better training of future surgeons. In this paper, a new virtual reality simulator, called RoSS is presented. Initial results from two studies - face and content validity, are very encouraging. 90% of the cohort of expert robotic surgeons felt that the simulator was excellent or somewhat close to the touch and feel of the daVinci console. Content validity of the simulator received 90% approval in some cases. These studies demonstrate that RoSS has the potential of becoming an important training tool for the daVinci surgical robot.

Objectives: To assess the face validity of Robotic Surgery Simulator (RoSS), a novel virtual reality training platform for the da Vinci Surgical System (DVSS)., Methods: Urologic surgeons, fellows, and residents attending the 2009 American Urologic Association Annual Meeting in April 2009 were invited to an orientation session with RoSS. Participants completed a questionnaire after orientation and two modules., Results: Thirty participants including 24 surgeons and fellows experienced with robotic surgery and 6 robotic surgery novices participated in the study. Eighty percent participants had at least 4 years of experience with robotic surgery and 77% had performed an average of 340 cases on the DVSS as primary console surgeons. Subjects indicated that RoSS was realistically close to the DVSS console in terms of virtual simulation and instrumentation. Fifty-two percent of subjects rated RoSS somewhat close and 45% rated RoSS very close to the DVSS console. Thirty-seven percent rated RoSS pinch device somewhat close, and 47% very close to the DVSS. With regard to movement of the arms, 43% rated it somewhat close, 40% rated it very close, and 7% felt that it was just like the DVSS. Camera movement and clutch functions were rated not close (11%), somewhat close (57%), and very close (32%) to the DVSS. Data were further analyzed in terms of surgical volume. Thirty-eight percent of subjects had also tried the Mimic dV-Trainer robotic surgery simulator., Conclusions: RoSS provides opportunity for robot-assisted surgical training for future error-free surgery. Further validation will be necessary to assess RoSS and the application of specific modules for robot-assisted surgical training., (Copyright 2010. Published by Elsevier Inc.)

Background: Recently, robotic systems have been introduced as a method for assisting endovascular interventional procedures. A few commercial and research solutions are available. In a survey it was found that none of the current systems satisfied all basic design requirements set forth for a good robot-assisted therapy platform., Methods: A human motion analysis study was performed to identify design specifications for safe motion and force limits for endovascular surgery. Based on design requirements from surveyed systems and motion analysis, a new, teleoperated, haptically enabled system called System for Endovascular Teleoperated Access (SETA) was constructed. SETA is capable of simultaneously manipulating any guidewire and catheter in the range of 0.014-0.13 inches., Results: SETA's slave was evaluated for precision positioning, using in vitro vascular phantoms. It was also evaluated by a cohort of neurovascular surgeons and fellows (n = 8), using the VIST vascular simulator. A qualitative survey of the participants and a quantitative analysis of metrics procedure time and contrast used found that SETA was equivalent to manual intervention on this platform., Conclusions: SETA provided good performance in the in vitro studies, and will soon be evaluated in a series of in vivo animal model studies., ((c) 2010 John Wiley & Sons, Ltd.)

Objective: To assess the utilization of a novel virtual reality robotic surgical simulator (RoSS) in surgical anatomy training and pattern recognition., Study Design: Ten surgical trainees (medical students and residents) were recruited to participate in a study that evaluated the efficacy of a robotic simulator in anatomy training. The subjects were divided into two groups of five individuals each. Each participant received a syllabus consisting of line diagrams and color pictures of the human anatomy. All participants were later tested on identifying the same five anatomical landmarks from photographs from actual laparoscopic procedures. Group I studied the syllabus and took the test. Group II similarly studied the syllabus, but were trained on the RoSS system using cognitive skill sets and then took the same test. Group II were asked to complete a posttest survey., Results: Mean time to complete the test was 142.8 seconds for group I and 118.4 seconds for group II. Mean number of errors committed by the group trained on RoSS was 0.4 out of 5, whereas the group that did not undergo training on RoSS committed 1.7 out of 5. The mean number of correct answers given by group I was 2.9 out of 5, whereas group II answered 4.2 out 5 correctly. All results were statistically significant. The subjects rated the anatomy module helpful, with a mean rating of 3.6 out of 5., Conclusions: RoSS is an effective tool in anatomy training. Further testing is underway to illustrate its important role in medical education and robotic surgical training.

Endovascular neurosurgery has gained acceptance as the best method of treatment of vascular abnormalities like cerebral aneurysms. However, the procedure is associated with difficulties in tool/tissue manipulation. Navigation of stent, catheter and, guide wire through complex arteries without any force information often causes stent snagging, plaque dislocations and formation of thrombosis caused by the damage of the arterial wall. Currently, there is no haptic device available which can provide the surgeons with the force information, related to stent placement procedure. The goal of this work is to create a data base for a fast synthetic endovascular force simulator, which will provide the surgeon with force information during tool-artery interaction, based on the various combinations of tool sizes and vessel complexity, [1, 2] to facilitate better preoperative planning, safer interventions, and advanced training of new surgeons.

Realistic trocar insertion simulator requires reliable and reproducible tissue data. This paper looks at using synthetic surrogate tissue to facilitate creation of data covering a wide range of pathological cases. Furthermore, we propose to map the synthetic puncture force data to the puncture force data obtained on animal/human tissue to create a simulation model of the procedure. We have developed an experimental setup to collect data from surrogate synthetic tissue using a bladeless trocar.

This paper describes our efforts at creating a system with real time acquisition and geometric processing of the patients vascular anatomy, supplemented by a framework to simulate catheter vasculature interaction. Our system uses biplane angiograms coupled with an algorithm for generation of 3D vascular trees for patient data acquisition. Surface reconstruction and processing of this data is performed to provide novel decision aids to the interventionalist. The processed data can be loaded in a virtual environment to simulate guidance of the catheter through the patient's vasculature. With our combination of techniques, a patient specific visualization and simulation environment can be prepared within the narrow time window available for this procedure.

The aim of computer haptics is to enable the user to touch, feel and maneuver virtual objects using a haptic interface. As the user "feels" the virtual object by applying force through the interface, complex calculations have to be done in real-time to generate a feedback force appropriate to the material properties of the object being "touched". In this paper we propose a method for modeling soft bodies, which incorporate non-linear, viscoelastic, anisotropic behavior that will enable real-time user interaction and still satisfy the high force-feedback frequency requirements. In this paper, we restrict the user interaction with virtual objects to palpation.

In advancing our capabilities in the realm of virtual reality, the development of haptic technology has been a rate-limiting factor in producing tactile sensations directly onto the human hands. The Living Anatomy Program seeks to obviate the need for such technology by designing physical objects based on anatomic components that feel realistic to the touch. Furthermore, synchronizing motion between physical and related virtual objects infinitely expands visual design options and provides a profound level of immersion into content.

Esophageal intubations are performed for urgent airway control in injured patients. Current methods of training include working on cadavers and mannequins, which lack the realism of a living human being. Work in this field has been limited due to the complex nature of simulating in real-time the interactive forces and deformations which occur during an actual patient intubation. This study addressed the issue of intubation training in an attempt to bridge the gap between actual and virtual patient scenarios. The two haptic devices along with the real-time performance of the simulator give it both visual and physical realism. The three dimensional viewing and interaction available through virtual reality make it possible for physicians, pre-hospital personnel and students to practice many esophageal intubations without ever touching a patient. The ability for a medical professional to practice a procedure multiple times prior to performing it on a patient will both enhance the skill of the individual while reducing the risk to the patient.

Modeling human organs and soft tissue or anatomic regions for the purpose of medical training and simulation is a relatively new area. The data presented here is the groundwork for our ongoing development of a real-time haptic virtual environment for abdominal soft tissue palpation. The purpose of modeling the human abdomen is twofold. First, to provide a mathematical description of soft tissue and organs and second, to simulate the behavior of realistic interactions in real-time within a virtual environment. We have developed a, non-invasive, system that will allow us to determine mathematical functions that model the deformation of individual layers of soft tissue within the human abdomen. This system has been tested, experimentally, with a viscoelastic polyester foam model. We have been able to determine the stiffness and force/displacement function of an object beneath two layers of foam having different material characteristics. These experimental results correlate well with known polyester foam material characteristics. In general, the calculated stiffness constants were within 5% of the actual value. The data presented in this study shows that this system may be a viable tool for accurate measurement of human soft tissue properties and behavioral response to palpation.