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ABSTRACT: This paper presents a fast numerical solution for the inverse kinematics of a serial manipulator. The method is implemented on the C-arm, a manipulator designed for use in robotic surgery. The inverse kinematics solution provides all possible solutions for any six degree-of-freedom serial manipulator, assuming that the forward kinematics are known and that it is possible to solve for the remaining joint angles if one joint angle's value is known. With a fast numerical method and the current levels of computing power, designing a manipulator with closed-form inverse kinematics is no longer necessary. When designing the C-arm, we therefore chose to weigh other factors, such as actuator size and patient safety, more heavily than the ability to find a closed-form inverse kinematics solution.
Applied Bionics and Biomechanics 09/2010; 7(3):209-216.
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ABSTRACT: The integration of human and robot into a single system offers remarkable opportunities for a new generation of assistive technology. Despite the recent prominence of upper limb exoskeletons in assistive applications, the human arm kinematics and dynamics are usually described in single or multiple arm movements that are not associated with any concrete activity of daily living (ADL). Moreover, the design of an exoskeleton, which is physically linked to the human body, must have a workspace that matches as close as possible with the workspace of the human body, while at the same time avoid singular configurations of the exoskeleton within the human workspace. The aims of the research reported in this manuscript are (1) to study the kinematics and the dynamics of the human arm during daily activities in a free and unconstrained environment, (2) to study the manipulability (isotropy) of a 7-degree-of-freedom (DOF)-powered exoskeleton arm given the kinematics and the dynamics of the human arm in ADLs. Kinematic data of the upper limb were acquired with a motion capture system while performing 24 daily activities from six subjects. Utilising a 7-DOF model of the human arm, the equations of motion were used to calculate joint torques from measured kinematics. In addition, the exoskeleton isotropy was calculated and mapped with respect to the spacial distribution of the human arm configurations during the 24 daily activities. The results indicate that the kinematic joint distributions representing all 24 actions appear normally distributed except for elbow flexion–extension with the emergence of three modal centres. Velocity and acceleration components of joint torque distributions were normally distributed about 0 Nm, whereas gravitational component distributions varied with joint. Additionally, velocity effects were found to contribute only 1/100th of the total joint torque, whereas acceleration components contribute 1/10th of the total torque at the shoulder and elbow, and nearly half of the total torque at the wrist. These results suggest that the majority of human arm joint torques are devoted to supporting the human arm position in space while compensating gravitational loads whereas a minor portion of the joint torques is dedicated to arm motion itself. A unique axial orientation at the base of the exoskeleton allowed the singular configuration of the shoulder joint to be moved towards the boundary of the human arm workspace while supporting 95% of the arm's workspace. At the same time, this orientation allowed the best exoskeleton manipulability at the most commonly used human arm configuration during ADLs. One of the potential implications of these results might be the need to compensate gravitational load during robotic-assistive rehabilitation treatment. Moreover, results of a manipulability analysis of the exoskeleton system indicate that the singular configuration of the exoskeleton system may be moved out of the human arm physiological workspace while maximising the overlap between the human arm and the exoskeleton workspaces. The collected database along with kinematic and dynamic analyses may provide a fundamental basis towards the development of assistive technologies for the human arm.
Applied Bionics and Biomechanics 07/2009; 6:175-191.
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ABSTRACT: Surgical guides may interfere with effective use of surgical instrumentation during implant placement in the posterior segments where interocclusal distance may be limited.
The purpose of this study was to measure and compare the accuracy of posterior implant placement using 3 precision surgical guides with varying occlusogingival heights, and to evaluate the difference in accuracy of implant placement through precision guides as compared to freehand placement.
Three groups of surgical guides were fabricated with occlusogingival heights of 4, 6, and 8 mm, respectively. A jig was fabricated to allow for accurate positioning in bone substitute blocks. Ninety implants were placed in the mandibular first molar site on a manikin. Thirty implants (Astra Tech AB) were placed for each group, with 15 through the guide and 15 freehand. Distances between a reference implant and each placed implant were measured at both implant and abutment levels using a coordinate measuring machine. Apex position and angular discrepancy were calculated using the coordinates of the centers of the implant platform and of the occlusal aspect of the abutment. Data was assessed using 2-way ANOVA (alpha=.05).
Two-way ANOVA demonstrated that guide height did not significantly affect the accuracy of the implant position. The distance from the reference point to the point of measurement was significantly smaller for placement through the guide compared to freehand placement at both implant (P<.001) and abutment levels (P<.001). The angular discrepancy was also significantly smaller for placement through the guide (P<.001).
Precision surgical guides with 4-mm occlusogingival height allow placement as accurate as precision guides with 8-mm height. Placement through the guide reproduced the target position more accurately than freehand insertion.
The Journal of prosthetic dentistry 06/2009; 101(6):372-81. · 1.22 Impact Factor
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Pablo Garcia, Jacob Rosen,
Chetan Kapoor,
Mark Noakes,
Greg Elbert,
Michael Treat,
Tim Ganous,
Matt Hanson,
Joe Manak,
Chris Hasser,
David Rohler,
Richard Satava
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ABSTRACT: The Trauma Pod (TP) vision is to develop a rapidly deployable robotic system to perform critical acute stabilization and/or surgical procedures, autonomously or in a teleoperative mode, on wounded soldiers in the battlefield who might otherwise die before treatment in a combat hospital could be provided.
In the first phase of a project pursuing this vision, a robotic TP system was developed and its capability demonstrated by performing selected surgical procedures on a patient phantom.
The system demonstrates the feasibility of performing acute stabilization procedures with the patient being the only human in the surgical cell. The teleoperated surgical robot is supported by autonomous robotic arms and subsystems that carry out scrub-nurse and circulating-nurse functions. Tool change and supply delivery are performed automatically and at least as fast as performed manually by nurses. Tracking and counting of the supplies is performed automatically. The TP system also includes a tomographic X-ray facility for patient diagnosis and two-dimensional (2D) fluoroscopic data to support interventions. The vast amount of clinical protocols generated in the TP system are recorded automatically.
Automation and teleoperation capabilities form the basis for a more comprehensive acute diagnostic and management platform that will provide life-saving care in environments where surgical personnel are not present.
International Journal of Medical Robotics and Computer Assisted Surgery 02/2009; 5(2):136-46. · 1.59 Impact Factor
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2009 IEEE International Conference on Robotics and Automation, ICRA 2009, Kobe, Japan, May 12-17, 2009; 01/2009
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I. J. Robotic Res. 01/2009; 28:1183-1197.
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ABSTRACT: A teleoperated surgical robotic system allows surgical procedures to be conducted across long distances while utilizing wired and wireless communication with a wide spectrum of performance that may affect the outcome. An open architecture portable surgical robotic system (Raven) was developed for both open and minimally invasive surgery. The system has been the subject of an intensive telesurgical experimental protocol aimed at exploring the boundaries of the system and surgeon performance during a series of field experiments in extreme environments (desert and underwater) teleportation between US, Europe, and Japan as well as lab experiments under synthetic fixed time delay. One standard task (block transfer emulating tissue manipulation) of the Fundamentals of Laparoscopic Surgery (FLS) training kit was used for the experimental protocol. Network characterization indicated a typical time delay in the range of 16-172 ms in field experiments. The results of the lab experiments showed that the completion time of the task as well as the length of the tool tip trajectory significantly increased (alpha< 0.02) as time delay increased in the range of 0-0.5 sec increased. For teleoperation with a time delay of 0.25s and 0.5s the task completion time was lengthened by a factor of 1.45 and 2.04 with respect to no time delay, whereas the length of the tools' trajectory was increased by a factor of 1.28 and 1.53 with respect to no time delay. There were no statistical differences between experienced surgeons and non-surgeons in the number of errors (block drooping) as well as the completion time and the tool tip path length at different time delays.
Conference proceedings: ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference 01/2009; 2009:6860-3.
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ABSTRACT: Within the area of telerobotic surgery no standardized means of surgically relevant performance evaluation has been established. The Society of American Gastrointestinal and Endoscopic Surgeons (SAGES) Fundamentals of Laparoscopic Surgery (FLS) program provides a set of standardized tasks that are considered the “gold standard” in surgical skill assessment. We present a methodology for using one of the SAGES FLS tasks for surgical robotic performance evaluation. The TeleRobotic FLS methodology is extendable to two other FLS tasks. Time delay in teleoperation in general and telesurgery in particular is one of the fundamental effects that limits performance in telerobotic surgery. In this pilot study the effect of time delay on the Block Transfer task performance was investigated. The RAVEN Surgical Robot was used in a master/slave configuration in which time delays of 0, 250, 500, and 1000 ms were introduced by a network emulator between the master (Surgeon Site) and the slave (Patient Site). The study included three subjects, each of whom was presented with three of the four conditions. The results show that one subject had a lower error rate with increasing time delay, whereas the other subjects had a higher error rate with increased delay. The subject with the longest average completion time suffered the least performance decrease under time delay.
Engineering in Medicine and Biology Society, 2008. EMBS 2008. 30th Annual International Conference of the IEEE; 09/2008
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ABSTRACT: As unmanned extraction vehicles become a reality in the military theater, opportunities to augment medical operations with telesurgical robotics become more plausible. This project demonstrated an experimental surgical robot using an unmanned airborne vehicle (UAV) as a network topology. Because battlefield operations are dynamic and geographically challenging, the installation of wireless networks is not a feasible option at this point. However, to utilize telesurgical robotics to assist in the urgent medical care of wounded soldiers, a robust, high bandwidth, low latency network is requisite. For the first time, a mobile surgical robotic system was deployed to an austere environment and surgeons were able to remotely operate the systems wirelessly using a UAV. Two University of Cincinnati surgeons were able to remotely drive the University of Washington's RAVEN robot's end effectors. The network topology demonstrated a highly portable, quickly deployable, bandwidth-sufficient and low latency wireless network required for battlefield use.
Telemedicine and e-Health 09/2008; 14(6):539-44. · 1.42 Impact Factor
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ABSTRACT: Robotic assisted surgery generates the possibility of remote operation between surgeon and patient. We need better understanding
of the engineering issues involved in operating a surgical robot in remote locations and through novel communication links
between surgeon and surgery site. This paper describes two recent experiments in which we tested the RAVEN, a new prototype
surgical robot manipulation system, in field and laboratory conditions. In the first experiment, the RAVEN was deployed in
a pasture and ran on generator power. Telecommunication with the surgical control station was provided by a novel airborne
radio link supported by an unmanned aerial vehicle. In the second experiment, the RAVEN was teleoperated via Internet between
Imperial College in London and the BioRobotics Lab at the University of Washington in Seattle. Data are reported on surgeon
completion times for basic tasks and on network latency experience. The results are a small step towards teleoperated surgical
robots which can be rapidly deployed in emergency situations in the field.
06/2008: pages 305-314;
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ABSTRACT: Accurate knowledge of biomechanical characteristics of tissues is essential for developing realistic computer-based surgical simulators incorporating haptic feedback, as well as for the design of surgical robots and tools. As simulation technologies continue to be capable of modeling more complex behavior, an in vivo tissue property database is needed. Most past and current biomechanical research is focused on soft and hard anatomical structures that are subject to physiological loading, testing the organs in situ. Internal organs are different in that respect since they are not subject to extensive loads as part of their regular physiological function. However, during surgery, a different set of loading conditions are imposed on these organs as a result of the interaction with the surgical tools. Following previous research studying the kinematics and dynamics of tool/tissue interaction in real surgical procedures, the focus of the current study was to obtain the structural biomechanical properties (engineering stress-strain and stress relaxation) of seven abdominal organs, including bladder, gallbladder, large and small intestines, liver, spleen, and stomach, using a porcine animal model. The organs were tested in vivo, in situ, and ex corpus (the latter two conditions being postmortem) under cyclical and step strain compressions using a motorized endoscopic grasper and a universal-testing machine. The tissues were tested with the same loading conditions commonly applied by surgeons during minimally invasive surgical procedures. Phenomenological models were developed for the various organs, testing conditions, and experimental devices. A property database-unique to the literature-has been created that contains the average elastic and relaxation model parameters measured for these tissues in vivo and postmortem. The results quantitatively indicate the significant differences between tissue properties measured in vivo and postmortem. A quantitative understanding of how the unconditioned tissue properties and model parameters are influenced by time postmortem and loading condition has been obtained. The results provide the material property foundations for developing science-based haptic surgical simulators, as well as surgical tools for manual and robotic systems.
Journal of Biomechanical Engineering 05/2008; 130(2):021020. · 1.90 Impact Factor
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ABSTRACT: Emphasis has been placed on improving patient outcomes in healthcare management. Significant patient morbidity and mortality exists from inappropriate procedural technique and percutaneous catheter needle insertion procedures have been linked to medical complications. Healthcare trainees learn these procedures through trial and error and most existing simulators are synthetic tissue based and lack in-vivo force feedback. We seek to utilize the Blue DRAGON instrument positioning system coupled with a force sensor to determine true forces experienced by a needle as it is passed through animal and human tissues in an effort to design a percutaneous needle insertion simulator that affords the learner with the experience of the true force feedback. Acquiring force displacement measurements of needle insertion is the first step towards development of a computational model of the phenomena. The computational model may be further incorporated into a medical haptic simulator that provides physically based force feedback to the user.
Studies in health technology and informatics 02/2008; 132:245-7.
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ABSTRACT: The Society of American Gastrointestinal Endoscopic Surgeons (SAGES) Fundamentals of Laparoscopic Surgery (FLS) program contains curriculum that includes both a cognitive and psychomotor skills. In this research the use of FLS Block Transfer task is used to evaluate the performance of surgeons' teleoperating the University of Washington Surgical robot. The use of the FLS Trainer Box and accessories kit provides a well-defined series of tasks that can be repeated by any researchers working in the field of surgical robotics so that systems can be evaluated using a common method.
Studies in health technology and informatics 02/2008; 132:263-5.
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ABSTRACT: Within the area of telerobotic surgery no standardized means of surgically relevant performance evaluation has been established. The Society of American Gastrointestinal and Endoscopic Surgeons (SAGES) Fundamentals of Laparoscopic Surgery (FLS) program provides a set of standardized tasks that are considered the 'gold standard' in surgical skill assessment. We present a methodology for using one of the SAGES FLS tasks for surgical robotic performance evaluation. The TeleRobotic FLS methodology is extendable to two other FLS tasks. Time delay in teleoperation in general and telesurgery in particular is one of the fundamental effects that limits performance in telerobotic surgery. In this pilot study the effect of time delay on the Block Transfer task performance was investigated. The RAVEN Surgical Robot was used in a master/slave configuration in which time delays of 0, 250, 500, and 1000 ms were introduced by a network emulator between the master (Surgeon Site) and the slave (Patient Site). The study included three subjects, each of whom was presented with three of the four conditions. The results show that one subject had a lower error rate with increasing time delay, whereas the other subjects had a higher error rate with increased delay. The subject with the longest average completion time suffered the least performance decrease under time delay.
Conference proceedings: ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference 02/2008; 2008:5597-600.
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Telemedicine and e-Health 09/2007; 13(4):369-80. · 1.42 Impact Factor
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ABSTRACT: With patient safety and improved outcomes as its focus, the Institute for Surgical and Interventional Simulation (ISIS), is dedicated to the training of medical professionals in technical and procedural skills, and research and development of emerging simulation technologies and educational strategies. ISIS is a collaborative institute of the University of Washington School of Medicine. It connects fifteen departments within the School of Medicine, the School of Nursing, the School of Dentistry, the Biorobotics Laboratory, the Human Interface Technology Lab, and the Center for Videoendoscopic Surgery. ISIS has active MOUs with other simulation centers at University of British Columbia, Oregon Health and Sciences University, and Madigan Army Medical Center, and a presence in Washington, Wyoming, Alaska, Montana, and Idaho. This model has applicability in civilian and military settings, as the collaboration with Madigan Army Medical Center (Andersen Simulation Center) demonstrates.
05/2007;
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ABSTRACT: The methodology for assessing medical skills is gradually shifting from subjective scoring of an expert which may be a variably biased opinion using vague criteria towards a more objective quantitative analysis. A methodology using Hidden Markov Modeling (HMM) and Markov Models (MM) were used to analyze database acquired the E-Pelvis (physical simulator) during a pelvic exam. The focus is on the method of selection of HMM parameters. K-Means is used to choose the alphabet size. Successful classification rates of 62% are observed with the HMM as opposed to 92% with the MM. Moreover, the MM provide an insight into the nature of the process while identifying typical sequences that are unique to each level of expertise, where the HM, given their nature as a black box model, do not.
Studies in health technology and informatics 02/2007; 125:316-8.
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ABSTRACT: With the development of new technologies in surgery, minimally invasive surgery (MIS) has drastically improved the way conventional medical procedures are performed. However, a new learning curve has resulted requiring an expertise in integrating visual information with the kinematics and dynamics of the surgical tools. The Red DRAGON is a multi-modal simulator for teaching and training MIS procedures allowing one to use it with several modalities including: simulator (physical objects and virtual objects) and an animal model. The Red DRAGON system is based on a serial spherical mechanism in which all the rotation axes intersect at a single point (remote center) allowing the endoscopic tools to pivot around the MIS port. The system includes two mechanisms that incorporate two interchangeable MIS tools. Sensors are incorporated into the mechanism and the tools measure the positions and orientations of the surgical tools as well as forces and torques applied on the tools by the surgeon. The design is based on a mechanism optimization to maximize the manipulability of the mechanism in the MIS workspace. As part of a preliminary experimental protocol, five expert level surgeons performed three laparoscopic tasks--a subset of the Fundamental Laparoscopic Skill (FLS) set as a baseline for skill assessment protocols. The results provide an insight into the kinematics and dynamics of the endoscopic tools, as the underlying measures for objectively assessing MIS skills.
Studies in health technology and informatics 02/2007; 125:149-54.
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ABSTRACT: Surgical simulators are excellent training tools for minimally invasive procedures but are currently lacking in realistic tissue rendering and tissue responses to manipulation. Accurate color representation of tissues may add realism to simulators and provide medically relevant information. The goal of this study was to determine feasible methods for measuring color of in vivo tissue, specifically liver, in a standardized color space. Several compressions were applied to in vivo porcine liver. Three methods were then used to determine the CIELab and/or sRGB colors of normal and damaged liver. Results suggest that there are significant differences between normal and damaged liver color.
Studies in health technology and informatics 02/2007; 125:109-11.
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Mitchell J H Lum, Jacob Rosen,
Hawkeye King,
Diana C W Friedman,
Gina Donlin,
Ganesh Sankaranarayanan,
Brett Harnett,
Lynn Huffman,
Charles Doarn,
Timothy Broderick,
Blake Hannaford
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ABSTRACT: Robotically assisted surgery stands to further revolutionize the medical field and provide patients with more effective healthcare. Most robotically assisted surgeries are teleoperated from the surgeon console to the patient where both ends of the system are located in the operating room. The challenge of surgical teleoperation across a long distance was already demonstrated through a wired communication network in 2001. New development has shifted towards deploying a surgical robot system in mobile settings and/or extreme environments such as the battlefield or natural disaster areas with surgeons operating wirelessly. As a collaborator in the HAPs/MRT (High Altitude Platform/Mobile Robotic Telesurgery) project, The University of Washington surgical robot was deployed in the desert of Simi Valley, CA for telesurgery experiments on an inanimate model via wireless communication through an Unmanned Aerial Vehicle (UAV). The surgical tasks were performed telerobotically with a maximum time delay between the surgeon's console (master) and the surgical robot (slave) of 20 ms for the robotic control signals and 200 ms for the video stream. This was our first experiment in the area of Mobile Robotic Telesurgery (MRT). The creation and initial testing of a deployable surgical robot system will facilitate growth in this area eventually leading to future systems saving human lives in disaster areas, on the battlefield or in other remote environments.
Studies in health technology and informatics 02/2007; 125:313-5.
