Abstracts

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PhD Thesis

"Telesurgery and Surgical Simulation: Design, Modeling, and Evaluation of Haptic Interfaces to Real and Virtual Surgical Environments." M. C. Cavusoglu. PhD Thesis. University of California, Berkeley, August 23, 2000.  Also UC Berkeley ERL Memo M00/43, August 2000.

Abstract

In this thesis, telesurgery and surgical simulation are treated as parallel research problems of haptic interfacing to real and virtual surgical environments, respectively. The analytical tools of systems and control theory and robotics are used to address several research problems in these areas.

The work on telesurgery is centered around the UC Berkeley/UC San Francisco Laparoscopic Telesurgical Workstation, focusing on the design and analysis of the system, with details of the design specifications, solution of the forward and inverse kinematics, and control issues. This is followed by a discussion on the general issues on the testing of the system. A novel approach using open surgical suturing motion data to evaluate the kinematics of a robotic telesurgical manipulator without prototyping a physical system is proposed within this context.

High fidelity teleoperation controller design for the telesurgical system is studied, and a theoretical and experimental framework is established for design and evaluation of teleoperation controllers for telemanipulation of deformable objects. In this study, the teleoperator control design is specifically for manipulation of deformable objects and uses a task based optimization scheme which explicitly takes into account human perceptual capabilities for the task at hand, telesurgery and stiffness discrimination. Integrated with this control design approach, two quantitative methods to analytically compare sensory schemes for teleoperators are proposed and a new experimental methodology to evaluate teleoperation control algorithms is presented for a stiffness discrimination task.

Dynamic simulation of deformable objects for interactive virtual environments is explored with emphasis on formulation of the problem, enabling technologies, and various modeling methods in the literature, mostly focusing on putting the existing methodologies into a unifying framework.

Finally, the problem of high fidelity haptic interaction with deformable objects in virtual environments is studied from a control theory point of view. A novel method to interface with deformable objects addressing the issues resulting from the difference between the haptic and deformable model simulation update rates is motivated, developed, and analyzed using the tools of modern control theory.

Keywords: Medical robotics, haptic interfaces, surgical simulation, robotic tools for surgery, virtual environments

Journal Papers

"A Laparoscopic Telesurgical Workstation."  M. C. Cavusoglu, F. Tendick, M. Cohn, and S. S. Sastry. In the IEEE Transactions on Robotics and Automation, Vol. 15, No. 4, August 1999, pp. 728-739.

Abstract

Medical robotics and computer aided surgery in general, and robotic telesurgery in particular, are promising applications of robotics.  In this paper, various aspects of telesurgery are studied.  After a general introduction to laparoscopic surgery and medical applications of robotics, the UC Berkeley/Endorobotics Inc./UC San Francisco Telesurgical Workstation, a master-slave telerobotic system for laparoscopic surgery, is introduced, followed by its kinematic analysis, control, and experimental results.  Later some conceptual and future issues on telesurgery are discussed, including teleoperation and hybrid control, focusing on the special requirements of telesurgery.

Keywords: Telesurgery, medical robotics, laparoscopy, minimally invasive surgery.

"A Virtual Environment Testbed for Training Laparoscopic Surgical Skills."  F. Tendick, M. Downes, T. Goktekin, M. C. Cavusoglu, D. Feygin, X. Wu, R. Eyal, M. Hegarty, and L. W. Way.  In Presence, Vol.  9, No. 3, June 2000 , pp. 236-255.

Abstract

With the introduction of minimally invasive techniques, surgeons must learn skills and procedures that are radically different from traditional open surgery.  Traditional methods of surgical training that were adequate when techniques and instrumentation changed relatively slowly may not be as efficient or effective in training substantially new procedures.  Virtual environments are a promising new medium for training.

This paper describes a testbed developed at the Berkeley and San Francisco campuses of the University of California for research in understanding, assessing, and training surgical skills.  The testbed includes virtual environments for training perceptual motor skills, spatial skills, and critical steps of surgical procedures.  Novel technical elements of the testbed include a four degree-of-freedom haptic interface, a fast collision detection algorithm for contact between rigid and deformable objects, and parallel processing of physical modeling and rendering.  The major technical challenge in surgical simulation to be investigated using the testbed is the development of accurate real time methods of modeling deformable tissue behavior.  Several simulations have been implemented in the testbed, including environments for assessing performance of basic perceptual motor skills, training the use of an angled laparoscope, and teaching critical steps of a common laparoscopic procedure, the cholecystectomy.  The major challenges of extending and integrating these tools for training are discussed.

"A Critical Study of the Mechanical and Electrical Properties of the PHANToM(TM) Haptic Interface and Improvements for High Performance Control." M. C. Cavusoglu, D. Feygin, and F. Tendick.  In Presence, Vol. 11, No. 6, December 2002, pp. 555-568.

Abstract

This paper presents a critical study of the mechanical and electrical properties of the Phantom haptic interface and improvements to overcome its limitations for applications requiring high performance control. Target applications share the common requirements of low noise/granularity/latency measurements, an accurate system model, high bandwidth, the need for an open architecture, and the ability to operate for long periods without interruption while exerting significant forces. To satisfy these requirements, the kinematics, dynamics, high frequency dynamic response, and velocity estimation of the Phantom system are studied. Furthermore, this paper presents the details of how the unknown subsystems of the stock Phantom can be replaced with known, high performance systems and additional measurement electronics can be interfaced to compensate for some of the Phantom's shortcomings. With these improvements, it is possible to increase the maximum achievable virtual wall stiffness by 35%, active viscous damping by 120%, and teleoperation loop gain by 50% over the original system. With the modified system, it is also possible to maintain higher forces for longer periods without causing motor overheating.

Keywords: Phantom force reflecting haptic interface

"Design of Bilateral Teleoperation Controllers for Haptic Exploration and Telemanipulation of Soft Environments." M. C. Cavusoglu, A. Sherman, and F. Tendick.  In the IEEE Transactions on Robotics and Automation, Vol. 18, No.4, August 2002, pp 641-647.

Abstract

In this paper, teleoperation controller design for haptic exploration and telemanipulation of soft environments is studied. First, a new measure for fidelity in teleoperation is introduced which quantifies the teleoperation system's ability to transmit changes in the compliance of the environment. This sensitivity function is appropriate for the application of telesurgery, where the ability to distinguish small changes in tissue compliance is essential for tasks such as detection of embedded vessels. The bilateral teleoperation controller design problem is then formulated in a task-based optimization framework as the optimization of this metric with constraints on free space tracking and robust stability of the system under environment and human operator uncertainties. The control design procedure is illustrated with a case study. The analysis is also used to evaluate the effectiveness of using a force sensor in a teleoperation system.

Keywords: Bilateral Control Design, Haptics, Telemanipulation of Soft Objects, Teleoperation

" Robotics for Telesurgery: Second Generation Berkeley/UCSF Laparoscopic Telesurgical Workstation and Looking towards the Future Applications "  M. C. Cavusoglu, W. Williams, F. Tendick, and S. S. Sastry.  In Industrial Robot, Special Issue on Medical Robotics, Vol. 30, No.1, January 2003, pp. 22-29.

Abstract

Robotic telesurgery is a promising application of robotics to medicine, aiming to enhance the dexterity and sensation of regular and minimally invasive surgery through using millimeter-scale robotic manipulators under control of the surgeon. With appropriate communication links, it would also be possible to perform remote surgery for care in rural areas where specialty care is unavailable, or to provide emergency care en route to a hospital. The second generation UC Berkeley/UCSF Telesurgical Workstation is a master-slave telerobotic system, with two pairs of 6 degree of freedom (DOF) master and slave robotic manipulators, designed for laparoscopic surgery. The slave manipulators have 2 DOF wrists inside the body to allow high dexterity manipulation in addition to the 4 DOF of motion possible through the entry ports, which are actuated by external gross motion platforms. The kinematics and the controller of the system are designed to accommodate the force and movement requirements of complex tasks, including suturing and knot tying. The system has force feedback in 4 axes to improve the sensation of telesurgery. In this paper, the telesurgical system will be introduced with discussion of kinematic and control issues and presentation of in vitro experimental evaluation results.

Keywords: Medical robotics, robotic telesurgery, laparoscopy.

" In Touch with Robotics: Neurosurgery for the Future."  N. Nathoo, M. C. Cavusoglu, M. A. Vogelbaum, and G. H. Barnett. In Nerosurgery. Vol. 56, No.3, March 2005, pp.421-433.

Abstract

The introduction of multiple front-end technologies during the past quarter century has generated an emerging futurism for the discipline of neurological surgery. Driven primarily by synergistic developments in science and engineering, neurosurgery has always managed to harness the potential of the latest technical developments. Robotics represents one such technology. Progress in development of this technology has resulted in new uses for robotic devices in our discipline, which are accompanied by new potential dangers and inherent risks. The recent surge in robot-assisted interventions in other disciplines suggests that this technology may be considered one of a spectrum of frontier technologies poised to fuel the development of neurosurgery and consolidate the era of minimalism. On a more practical level, if the introduction of robotics in neurosurgery proves beneficial, neurosurgeons will need to become facile with this technology and learn to harness its potential so that the best surgical results may be achieved in the least invasive manner. This article reviews the role of robotic technology in the context of neurosurgery.

Keywords: Computer-directed surgery, Neurosurgery, Robot, Robotic technology

Book Chapters

"Telesurgery and Surgical Simulation: Haptic Interfaces to Real and Virtual Surgical Environments."  M. C. Cavusoglu, F. Tendick, and S. S. Sastry.  In McLaughlin, M. L., Hespanha, J. P., and Sukhatme, G., editors. Touch in virtual environments. IMSC Series in Multimedia. Prentice-Hall. 2002.

Abstract

In this paper, telesurgery and surgical simulation are introduced as parallel research problems of haptic interfacing to real and virtual surgical environments. The analytical tools of systems and control theory and robotics are used to address several research problems in these areas. The discussion on telesurgery is centered around the UC Berkeley/UC San Francisco Laparoscopic Telesurgical Workstation, focusing on the design of the system and high fidelity teleoperation controller design. Second part of the paper describes a testbed developed at the San Francisco, Berkeley, and Santa Barbara campuses of the University of California for research in understanding, assessing, and training surgical skills. The testbed includes virtual environments for training perceptual motor skills, spatial skills, and critical steps of surgical procedures. Within this context, a novel method to interface with deformable objects addressing the issues resulting from the difference between the haptic and deformable model simulation update rates is presented.

Keywords: ??

Conference Papers

"Human Hand Trajectory Analysis in Point-and-Direct Telerobotics."  T. T. Blackmon, M. C. Cavusoglu, F. Lai, and L. W. Stark.  In Proceedings of the 8th International Conference on Advanced Robotics (ICAR '97), Monterey, CA, July 7-9, 1997, pp. 927-932.

Abstract

Human hand trajectories have been recorded and analyzed in an experimental supervisory control interface for a telerobot manipulator. Using a six degree-of-freedom tracking device to control the gripper of a computer graphics simulation model of the telerobot, human operators were instructed to command the telerobot under a variety of visual conditions. Analysis of the human hand trajectories shows considerable distortion and adaptation e ects in the virtual environments. Also, the nature of the 3D hand trajectories for the reaching task lends support for a sampled-data model of human neurological control; this has design implications for telerobotic interfaces.

Keywords: Telerobotics, supervisory control, hand movements, virtual environments.

"A Hybrid System Approach to Contact Stability and Force Control in Robotic Manipulators."  M. C. Cavusoglu, J. Yan, and S. S. Sastry. In Proceedings of the 12th IEEE International Symposium on Intelligent Control (ISIC'97), Istanbul, Turkey, July 16-18, 1997, pp. 143-148.

Abstract

Force control and manipulation involving contacts are essentially hybrid control problems because of the inherent switching present in the dynamic behavior when the manipulator comes in contact with and leaves a surface. In this study, the game theoretic approach of hybrid control design is used to synthesize the least restrictive control law for a robotic manipulator to establish and maintain contact with a surface while keeping interaction forces within specified bounds.

"Human Machine Interfaces for Minimally Invasive Surgery."  F. Tendick, and M. C. Cavusoglu.  In Proceedings of the 19th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBS'97), Chicago, IL, October 30- November 2, 1997, pp. 2771-2776.

Abstract

Increasing numbers of surgical procedures are performed using minimally invasive techniques, in which trauma to external tissue is minimized. Unfortunately, reduced access reduces dexterity, limits perception, increases strain and the likelihood of error, and lengthens procedure time. Surgical technology must improve the interface between task requirements and human abilities. This paper describes three projects to evaluate and improve the human interface in laparoscopic surgery, or minimally invasive surgery of the abdomen: (a) measurement ofmovement trajectories under different visual conditions to determine the effect of viewing geometry, (b) the development of virtual environments for training, and (c) the development of haptic interfaces and control algorithms for teleoperative surgery.

Keywords: Laparoscopic surgery, video displays, virtual environments, teleoperation

"Laparoscopic Telesurgical Workstation."  M. C. Cavusoglu, M. Cohn, F. Tendick, and S. S. Sastry.  In Proceedings of the SPIE International Symposium on Biological Optics (BIOS'98) , San Jose, CA, January 24-30, 1998, pp. 296-303.

Abstract

Robotic telesurgery is a promising application of robotics to medicine, aiming to enhance the dexterity and sensation of minimally invasive surgery through millimeter-scale manipulators under control of the surgeon. With appropriate communication links, it would also be possible to perform remote surgery for care in rural areas where specialty care is unavailable, or to provide emergency care en route to a hospital. The UC Berkeley/Endorobotics/UCSF Telesurgical Workstation is a master-slave telerobotic system, with two 6 degree of freedom (DOF) robotic manipulators, designed for laparoscopic surgery. The slave robot has a 2 DOF wrist inside the body to allow high dexterity manipulation in addition to the 4 DOF of motion possible through the entry port, which are actuated by an external gross motion platform. The kinematics and the controller of the system are designed to accommodate the force and movement requirements of complex tasks, including suturing and knot tying. The system has force feedback in 4 axes to improve the sensation of telesurgery. In this paper, the telesurgical system will be introduced with discussion of kinematic and control issues and presentation of in vitro test results.

Keywords: Robotic Telesurgery, Medical Robotics, Laparoscopy

"Development of Virtual Environments for Training Skills and Reducing Errors in Laparoscopic Surgery."  F. Tendick, M. S. Downes, M. C. Cavusoglu, and L. W. Way.  In Proceedings of the SPIE International Symposium on Biological Optics (BIOS'98) , San Jose, CA, January 24-30, 1998, pp. 36-44.
 

Abstract

In every surgical procedure there are key steps and skills that, if performed incorrectly, can lead to complications.  In conjunction with efforts, based on task and error analysis, in the Videoscopic Training Center at UCSF to identify these key elements in laparoscopic surgical procedures, the authors are developing virtual environments and modeling methods to train the elements.  Laparoscopic surgery is particularly demanding of the surgeon's spatial skills, requiring the ability to create three-dimensional mental models and plans while viewing a two-dimensional image.  For example, operating a laparoscope with the objective lens angled from the scope axis is a skill that some surgeons have difficulty mastering, even after using the instrument in many procedures.  Virtual environments are a promising medium for teaching spatial skills.  A kinematically accurate model of an angled laparoscope in an environment of simple targets is being tested in courses for novice and experienced surgeons.  Errors in surgery are often due to a misinterpretation of local anatomy compounded with inadequate procedural knowledge.  Methods to avoid bile duct injuries in cholecystectomy (gallbladder removal) are being integrated into a deformable environment consisting of the liver, gallbladder, and biliary tree.  Novel deformable tissue modeling algorithms based on finite element methods will be used to improve the response of the anatomical models.

"Virtual Environments for Training Critical Skills in Laparoscopic Surgery."  M. S. Downes, M. C. Cavusoglu, W. Gantert, L. W. Way, and F. Tendick.  In Proceedings of Medicine Meets Virtual Reality VI (MMVR'98) , San Diego, CA, January 28-31, 1998, pp. 316-322.
 

Abstract

Surgical training simulations must incorporate not only advanced technical features, such as detailed geometric organ models and physically-based modeling techniques, but also a thorough understanding of the major training issues relating to a particular procedure. We have developed a prototype environment for training laparoscopic cholecystectomy, or gallbladder removal surgery, which focuses a student's attention on the critical steps performed during the procedure and provides feedback as to the common errors committed during a session. The current version of our system runs in real-time on a mid-range graphics workstation. The simulation also provides a platform for research into a variety of different areas, including tissue modeling, finite element methods, and generalized simulation authoring.

"Laparoscopic Telesurgical Workstation."  M. C. Cavusoglu, M. Cohn, F. Tendick, and S. S. Sastry.  In the Video Proceedings of the IEEE International Conference on Robotics and Automation (ICRA'99), Detroit, MI, May 10-15, 1999.

Abstract

Robotic telesurgery is a promising application of robotics to medicine, aiming to enhance the dexterity and sensation of minimally invasive surgery through millimeter-scale manipulators under control of the surgeon. With appropriate communication links, it would also be possible to perform remote surgery for care in rural areas where specialty care is unavailable, or to provide emergency care en route to a hospital. The UC Berkeley/Endorobotics/UCSF Telesurgical Workstation is a master-slave telerobotic system, with two 6 degree of freedom (DOF) robotic manipulators, designed for laparoscopic surgery. The slave robot has a 2 DOF wrist inside the body to allow high dexterity manipulation in addition to the 4 DOF of motion possible through the entry port, which are actuated by an external gross motion platform. The kinematics and the controller of the system are designed to accommodate the force and movement requirements of complex tasks, including suturing and knot tying. In this video, the telesurgical system will be introduced, followed by a video clip from the in vivo suturing and knot tying tasks performed at the Experimental Surgery Laboratory of University of California at San Francisco, by the resident surgeons.

Keywords:  Telesurgery, medical robotics, laparoscopy, minimally invasive surgery.

"Modeling the Dynamics of the Human Thigh for a Realistic Echographic Simulator with Force Feedback."  D. d'Aulignac, M. C. Cavusoglu, and C. Laugier. In the Proceedings of the Second International Conference on Medical Image Computing and Computer-Assisted Intervention (MICCAI’99), Cambridge, England, September 19-22, 1999.

Abstract

Not available

"Towards a Realistic Echographic Simulator with Force Feedback."  D. d'Aulignac, C. Laugier, and M. C. Cavusoglu. In the Proceedings of the IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS'99), Kyongju, Korea, October 17-21, 1999, pp.727-732.

Abstract

This paper proposes a mass-spring model of a human thigh based on real data acquired.  It addresses both the difficulties of determining the parameters of this model to fit the measurements and the computational demands.  Implicit integration is used to update the model through time.  The motivation behind this work is to provide accurate force-feedback for an echographic simulator that could be used to train practitioners to detect a trombosis.

"Multirate Simulation for High Fidelity Haptic Interaction with Deformable Objects in Virtual Environments."  M. C. Cavusoglu, F. Tendick.  In Proceedings of the IEEE International Conference on Robotics and Automation (ICRA 2000), San Francisco, CA, April 24-28, 2000, pp. 2458-2465.

Abstract

Haptic interaction is an increasingly common form of interaction in virtual environment (VE) simulations.  This medium introduces some new challenges.  In this paper we study the problem arising from the difference between the sampling rate requirements of haptic interfaces and the significantly lower update rates of the physical models being manipulated.  We propose a multirate simulation approach which uses a local linear approximation.  The treatment includes a detailed analysis and experimental verification of the approach.  The proposed method is also shown to improve the stability of the haptic interaction.

Keywords:  Balanced model reduction, deformable models, haptic interfacing, virtual reality, virtual environments.

"Maximizing the Sensation of Compliance in Teleoperative Surgery."  F. Tendick, M.C. Cavusoglu, N. Dhruv, and A. Sherman.  In Proccedings of the Eighth International Symposium on Robotics with Applications, part of the World Automation Congress (WAC 2000), Maui, HI, June 11-16, 2000.

Abstract

Minimally invasive surgery (MIS) can be of great benefit to the patient, but places great demands on the surgeon's perceptual motor skills. Teleoperation technology can restore some of the lost dexterity and sensation in MIS. In this paper, we describe (a) experiments to determine human capability to discriminate changes in compliance displayed through a haptic interface and (b) analysis of teleoperator control algorithms to optimize the transmission of compliance. The paradigm used in both cases is the ability to detect a change in compliance of a surface, as would occur due to a lesion or vessel embedded in soft tissue. It is shown that sensitivity to sinusoidal variations in compliance across a surface at high spatial frequencies is much better than discrimination between two compliant surfaces. A new metric for teleoperator performance is introduced which optimizes the transmission of changes in compliance while maintaining adequate stability and tracking accuracy.

Keywords: Haptics, teleoperation, minimally invasive surgery, psychophysics.

"Comparison of Teleoperator Control Architectures for Palpation Task."  A. Sherman, M. C. Cavusoglu, F. Tendick. In Proceedings of the Symposium on Haptic Interfaces for Virtual Environment and Teleoperator Systems, part of the ASME International Mechanical Engineering Congress and Exposition (IMECE 2000), Orlando, FL, November 5-10, 2000.

Abstract

This work focuses on the design and testing of teleoperation controllers which are required to discriminate changes in compliance, addressing the question of which controller architecture performs the best in the high fidelity application of telesurgery. Three teleoperator controller architectures are compared for their ability to detect objects in compliant environments. These architectures are: position error based force feedback (PERR), kinesthetic force feedback (KFF), and position and force feedback (P+FF). The gains for each controller are chosen based on stability, tracking performance, and fidelity of the system. Stability is determined by a robust stability criterion. A sensitivity function is used to determine a tracking criterion.  A new fidelity measure is introduced which looks at the sensitivity of the transmitted impedance to changes in the environmental compliance. Experiments are conducted to determine which control architecture allows the operator to most easily determine a change in compliance. This experimental task is designed to mimic palpation of soft tissue performed in medical procedures. The results suggest that the hybrid controller (P+FF) outperforms both PERR and KFF.

Keywords:  Haptics, Teleoperation, Palpation, Telemanipulation of Soft Objects, Telesurgery.

"Bilateral Controller Design for Telemanipulation in Soft Environments."  M. C. Cavusoglu, A. Sherman, F. Tendick.  In Proceedings of the IEEE International Conference on Robotics and Automation (ICRA 2001), Seoul, Korea, May 21-26, 2001.

Abstract

Previous research on teleoperation has focused on manipulation of hard objects.  However, the design constraints are different in applications that involve manipulation of deformable objects, such as robotic telesurgery.  In this paper a new measure for fidelity in teleoperation is introduced which quantifies the teleoperation system's ability to transmit changes in the compliance of the environment.  This sensitivity function is highly appropriate for the application of telesurgery, where the ability to distinguish small changes in tissue compliance is essential for tasks such as tumor detection. The bilateral teleoperation controller design problem is then formulated as the optimization of this new metric with constraints on free space tracking requirements and robust stability of the system under environment and human operator uncertainties.  The robust stability analysis can be applied to any teleoperator plant and guarantee stability given an uncertainty model.  The analysis is also extended to evaluate effectiveness of using a force sensor in the teleoperation system.

Keywords:  Bilateral Control Design, Haptics, Robust Stability, Telemanipulation of Soft Objects, Teleoperation

"Workspace Analysis of Robotic Manipulators for a Teleoperated Suturing Task."  M. C. Cavusoglu, I. Villanueva, F. Tendick. In Proceedings of the IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS 2001), Maui, HI, October 29-November 3, 2001.

Abstract

An important missing piece in the medical robotics literature is the lack of systematic methods to quantitatively compare different manipulator designs, and to evaluate kinematic configurations chosen for telesurgical manipulators in application-critical tasks. Such a quantitative method is especially important during design stage to make an informed decision between various design alternatives. In this paper, a quantitative method to evaluate the kinematic ability of surgical manipulators to perform the critical tasks of suturing and knot tying is presented. The proposed method does not require a physical prototype. This is achieved by running typical tool motions during these tasks through the inverse kinematics of the manipulators and checking if the system can accommodate the desired motions. The system can perform a given motion if the whole trajectory lies continuously within the workspace of the manipulator. Open surgical suturing motion data collected from experiments done with expert surgeons is used as the set of desired tool motions used in the analysis. The method is applied to compare two different wrist configurations of telesurgical slave manipulators, intended for use in minimally invasive surgery, by looking at the requirements on joint ranges and wrist manipulability during these motions.

Keywords: Medical robotics, robotic telesurgery, kinematics, workspace analysis, laparoscopy, thoracoscopy.

"Robotics for Telesurgery: Second Generation Berkeley/UCSF Laparoscopic Telesurgical Workstation and Looking towards the Future Applications."  M. C. Cavusoglu, W. Williams, F. Tendick, S.S. Sastry. In the Proceedings of the 39th Allerton Conference on Communication, Control and Computing, Monticello, IL, October 3-5, 2001. (Invited paper). 

Abstract

Robotic telesurgery is a promising application of robotics to medicine, aiming to enhance the dexterity and sensation of regular and minimally invasive surgery through using millimeter-scale robotic manipulators under control of the surgeon. With appropriate communication links, it would also be possible to perform remote surgery for care in rural areas where specialty care is unavailable, or to provide emergency care en route to a hospital. The second generation UC Berkeley/UCSF Telesurgical Workstation is a master-slave telerobotic system, with two pairs of 6 degree of freedom (DOF) master and slave robotic manipulators, designed for laparoscopic surgery. The slave manipulators have 2 DOF wrists inside the body to allow high dexterity manipulation in addition to the 4 DOF of motion possible through the entry ports, which are actuated by external gross motion platforms. The kinematics and the controller of the system are designed to accommodate the force and movement requirements of complex tasks, including suturing and knot tying. The system has force feedback in 4 axes to improve the sensation of telesurgery. In this paper, the telesurgical system will be introduced with discussion of kinematic and control issues and presentation of in vitro experimental evaluation results.

Keywords: Medical robotics, robotic telesurgery, laparoscopy.

"Kalman Filter Analysis for Quantitative Comparison of Sensory Schemes in Bilateral Teleoperation Systems." M. C. Cavusoglu, and F. Tendick. In Proccedings of the IEEE International Conference on Robotics and Automation (ICRA 2003), Taipei, Taiwan, May 12-17, 2003.

Abstract

An important area of research in the teleoperation literature is to develop systematic methods to quantitatively compare different manipulator designs in application critical tasks. Such quantitative methods are especially important during design of the manipulators to make an informed decision among various design alternatives. In this paper, a novel method to quantitatively compare different sensory schemes for a teleoperation system is introduced. This method evaluates the sensory schemes by comparing the norm of the {\em a posteriori} error covariance matrices of the Kalman filters for each configuration. The main advantage of this method is that it allows to quantitatively compare arbitrary sensory configurations.

Keywords: Bilateral Teleoperation Control Design, Haptics, Telemanipulation, Teleoperation, Telesurgery

"GiPSi: An Open Source/Open Architecture Software Development Framework for Surgical Simulation." M. C. Cavusoglu, T. G. Goktekin, F. Tendick, and S. S. Sastry. In  Proceedings of Medicine Meets Virtual Reality XII (MMVR 2004), Newport Beach, CA, January 14-17, 2004, Toronto, Canada, November 4-11, 2003.

Abstract.

In this paper we propose an open source/open architecture framework for developing organ level surgical simulations. Our goal is to facilitate shared development of reusable models, to accommodate heterogeneous models of computation, and to provide a framework for interfacing multiple heterogeneous models. The framework provides an intuitive API for interfacing models with spatial relationships. It is specifically designed to be independent of the specifics of the modeling methods used and therefore facilitates seamless integration of heterogeneous models and processes. Furthermore, each model has separate geometries for visualization, simulation and interfacing, allowing the modeler choose the most natural geometric representation for each case. I/O interfaces for visualization and haptics for real-time interactive applications have also been provided.

Keywords: Surgical simulation, open source surgical simulation, heart simulation.

"GiPSi: An Open Source/Open Architecture Software Development Framework for Surgical Simulation." T. Goktekin, M.C. Cavusoglu, F. Tendick, and S. S. Sastry. In Proceedings of the International Symposium on Medical Simulation, Cambridge, MA, June17-18, 2004. pp. 240-248.

Abstract.

In this paper we propose an open source/open architecture framework for developing organ level surgical simulations. Our goal is to facilitate shared development of reusable models, to accommodate heterogeneous models of computation, and to provide a framework for interfacing multiple heterogeneous models. The framework provides an intuitive API for interfacing dynamic models defined over spatial domains. It is specifically designed to be independent of the specifics of the modeling methods used and therefore facilitates seamless integration of heterogeneous models and processes. Furthermore, each model has separate geometries for visualization, simulation, and interfacing, allowing the modeler to choose the most natural geometric representation for each case. I/O interfaces for visualization and haptics for real-time interactive applications have also been provided.

Keywords: ???

"Virtual Reality as a Training Tool for Endoscopic Neurosurgical Procedures." S. Manjila, M. C. Cavusoglu, N. Brown, A. R. Cohen. The 33rd Annual Meeting of the AANS/CNS Section on Pediatric Neurological Surgery, San Francisco, CA, December 8-11, 2004

Abstract.

Not Available.

Keywords: ???

Technical Reports

"Closed Loop Position and Force Control of Anthrobot III Robot Hand."   M. C. Cavusoglu, G. Avkarogullari, and I.S. Koc. B.S. Project Report, (also report for TUBITAK AEAGE Project No 95-20-100), Department of Electrical and Electronic Engineering, Middle East Technical University, Ankara, Turkey, Spring 1996.

Abstract

Not available.

"Control of a Telesurgical Workstation."  M. C. Cavusoglu. M.S. Project Report.  University of California at Berkeley, May 20, 1997.  Also UC Berkeley ERL Memo M97/35, May 1997.

Abstract

Medical robotics and computer aided surgery in general, and robotic telesurgery in particular, are promising applications of robotics. In this report, various aspects of telesurgery are studied. After a general introduction to laparoscopic surgery and medical applications of robotics, in the first part, the UC Berkeley Telesurgical Workstation, a master-salve telerobotic system for laparoscopic surgery, is introduced, followed by its kinematic analysis and discussion on its control. In the second part, conceptual and future issues on telesurgery are studied in detail, including discussions on teleoperation, hybrid control and visualization. Discussions on teleoperation introduce the fidelity-stability trade-off  in teleoperation systems, give a general overview of the control algorithms present in the literature, and discuss the special requirements of telesurgery. Hybrid control is used to design the least restrictive control law for the telesurgical robot to limit the interaction forces for guaranteed safe operation. The visualization section discusses the general problems of the display system used in laparoscopic surgery, and proposes ways to overcome them, with a case study on 3D surface reconstruction from camera motion in laparoscopic images.

Abstract

Haptic interaction is an increasingly common form of interaction in virtual environment (VE) simulations.  This medium introduces some new challenges.  In this paper we study the problem arising from the difference between the sampling rate requirements of haptic interfaces and the significantly lower update rates of the physical models being manipulated.  We propose a multirate simulation approach which uses a local linear approximation.  The treatment includes a detailed analysis and experimental verification of the approach.  The proposed method is also shown to improve the stability of the haptic interaction.

Keywords:  Balanced model reduction, deformable models, haptic interfacing, virtual reality, virtual environments.

Abstract

In this report, derivation of the kinematic and dynamic equations of PHANToM(TM) model 1.5 manipulator are presented.

Keywords:  N/A.