Diana C. W. Friedman

The RAVEN: Design and Validation of a Telesurgery System

The collaborative effort between fundamental science, engineering and medicine provides physicians with improved tools and techniques for delivering effective health care. Minimally invasive surgery (MIS) techniques have revolutionized the way a number of surgical procedures are performed. Recent advances in surgical robotics are once again revolutionizing MIS interventions and open surgery. In an earlier research endeavor, 30 surgeons performed 7 different MIS tasks using the Blue Dragon system to collect measurements of position, force, and torque on a porcine model. This data served as the foundation for a kinematic optimization of a spherical surgical robotic manipulator. Following the optimization, a seven-degree-of-freedom cable-actuated surgical manipulator was designed and integrated, providing all degrees of freedom present in manual MIS as well as wrist joints located at the surgical end-effector. The RAVEN surgical robot system has the ability to teleoperate utilizing a single bi-directional UDP socket via a remote master device. Preliminary telesurgery experiments were conducted using the RAVEN. The experiments illustrated the system’s ability to operate in extreme conditions using a variety of network settings.

Raven-II: An Open Platform for Surgical Robotics Research

The Raven-II is a platform for collaborative research on advances in surgical robotics. Seven universities have begun research using this platform. The Raven-II system has two 3-DOF spherical positioning mechanisms capable of attaching interchangeable four DOF instruments. The Raven-II software is based on open standards such as Linux and ROS to maximally facilitate software development. The mechanism is robust enough for repeated experiments and animal surgery experiments, but is not engineered to sufficient safety standards for human use. Mechanisms in place for interaction among the user community and dissemination of results include an electronic forum, an online software SVN repository, and meetings and workshops at major robotics conferences.

Teleoperation in surgical robotics – network latency effects on surgical performance

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 (α< 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.

Portable surgery master station for mobile robotic telesurgery

We describe a system that provides a low-cost, portable control station for experimentation in mobile robotic telesurgery. The software and hardware implementation of our system are described in detail. The device mapping between the Haptic Interface Devices (HID) and the surgical robot that enable the surgeon to effectively teleoperate the surgical robot are explained along with our communication protocols for telesurgery. We have also provided our initial results from extensive field testing of our system in different hardware and software configurations and challenging locations. We focus on working under sub-optimal network conditions for field operation in remote environments, and the importance of interoperability and distribution among networked surgical technologies.

Teleoperation of a Surgical Robot via Airborne Wireless Radio and Transatlantic Internet Links

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.

Instrument Failures for the da Vinci Surgical System: a Food and Drug Administration MAUDE Database Study

BackgroundOur goal was to analyze reported instances of the da Vinci robotic surgical system instrument failures using the FDAs MAUDE (Manufacturer and User Facility Device Experience) database. From these data we identified some root causes of failures as well as trends that may assist surgeons and users of the robotic technology.MethodsWe conducted a survey of the MAUDE database and tallied robotic instrument failures that occurred between January 2009 and December 2010. We categorized failures into five main groups (cautery, shaft, wrist or tool tip, cable, and control housing) based on technical differences in instrument design and function.ResultsA total of 565 instrument failures were documented through 528 reports. The majority of failures (285) were of the instrument’s wrist or tool tip. Cautery problems comprised 174 failures, 76 were shaft failures, 29 were cable failures, and 7 were control housing failures. Of the reports, 10 had no discernible failure mode and 49 exhibited multiple failures.ConclusionsThe data show that a number of robotic instrument failures occurred in a short period of time. In reality, many instrument failures may go unreported, thus a true failure rate cannot be determined from these data. However, education of hospital administrators, operating room staff, surgeons, and patients should be incorporated into discussions regarding the introduction and utilization of robotic technology. We recommend institutions incorporate standard failure reporting policies so that the community of robotic surgery companies and surgeons can improve on existing technologies for optimal patient safety and outcomes.

Automated Tool Handling for the Trauma Pod Surgical Robot

In order to enable robotic surgery without human assistance, a means must be developed to change tools. As part of the larger Trauma Pod Project, we developed the Tool Rack Subsystem - an automated tool rack capable of holding, accepting, and dispensing up to 14 tools for the da Vinci surgical robot. Borrowing some techniques from industrial automation, we developed a robust system capable of presenting any stored tool in 700ms or less. Tools are positively retained in a sterilizable carousel in a compliant manner designed to accomodate misalignment during tool exchange. RFID equipment is integrated into the system and the tools so that tools can be inventoried and presented by function or serial number instead of rack position. The resulting device has completed testing and integration into the Trauma Pod system and met all its design requirements.

Multiportal Robotic Access to the Anterior Cranial Fossa: A Surgical and Engineering Feasibility Study

Objective Integration of robotic surgical technology into skull base surgery is limited due to minimum angle requirements between robotic tools (narrow funnel effect), steep angle of approach, and instrumentation size. The objectives of this study were to systematically analyze surgical approach portals using a computer model, determine optimal approaches, and assess feasibility of the derived approaches on robotic surgical systems. Study Design Computer analysis on 10 computed tomography scans was performed to determine approach trajectories, angles between robotic tools, and distances to specified skull base target locations for transorbital and transnasal surgical approach portals. Setting Dry laboratory and cadaver laboratory. Subjects and Methods The optimal combinations were tested on the da Vinci and Raven robotic systems. Results Multiportal analyses showed the angles between 2 robotic tools were 14.7, 28.3, and 52.0 degrees in the cases of 2 transnasal portals, combined transnasal and medial orbit portals, and bilateral superior orbit portals, respectively, approaching a prechiasmatic target. The addition of medial and superior transorbital portals improved the skull base trajectory angles 21 and 27 degrees, respectively. Two robotic tools required an angle of at least 20 degrees between them to function effectively at skull base targets. Conclusion Technical feasibility of robotic transorbital and transnasal approaches to access sella and parasellar target locations was demonstrated. This technique addresses the 2 major drawbacks of (1) the narrow funnel effect generated from portals in close proximity and (2) the steep angle of approach to the skull base, as observed in previous studies analyzing transoral, transcervical, transmaxillary, and transhyoid portals.

Freeing the serial mechanism designer from inverse kinematic solvability constraints

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 angles 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.

Multiportal Robotic Access to the Anterior Cranial Fossa: An Engineering and Surgical Feasibility Study

Objectives: Use of robotic surgical technology in skull base surgery has been limited due to the need for 3 non-disruptive surgical portals; adequate working space between the large robotic arms; and the steep approach angle to the skull base. The objectives were to determine the minimum space requirements between robotic arms, systematically analyze surgical approach portals in a computer model, and assess task performance capability of the derived approaches. Methods: A computer analysis on 10 computed tomography scans computed approach trajectory angles and distances to specified skull base target locations for multiportal surgical approaches. The optimal combinations of portals were tested using the da Vinci and Raven robotic systems to perform tasks, both in dry lab and cadaver settings. Results: Two robotic tools required an angle of at least 20 degrees between them to function effectively at the skull base targets. In the computer analysis, the angle between two transnasal robotic tools was 14.7, and combining with transorbital portals yielded angles much larger (up to 46.0 degrees). Additionally, the skull base trajectory angle was improved by greater than 28 degrees. Conclusions: Computer analysis and cadaver testing demonstrated that the optimal multiportal combination to access sella and parasellar target locations was using 1 transnasal and 2 transorbital portals. This technique addresses the 2 major challenges of 1) the narrow funnel effect generated from portals in close proximity and 2) the steep angle of approach to the skull base, reported in studies evaluating transoral, transcervical, transmaxillary, and transhyoid portals.