Ganesh Sankaranarayanan

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.

Common uses and cited complications of energy in surgery

BackgroundInstruments that apply energy to cut, coagulate, and dissect tissue with minimal bleeding facilitate surgery. The improper use of energy devices may increase patient morbidity and mortality. The current article reviews various energy sources in terms of their common uses and safe practices.MethodsFor the purpose of this review, a general search was conducted through NCBI, SpringerLink, and Google. Articles describing laparoscopic or minimally invasive surgeries using single or multiple energy sources are considered, as are articles comparing various commercial energy devices in laboratory settings. Keywords, such as laparoscopy, energy, laser, electrosurgery, monopolar, bipolar, harmonic, ultrasonic, cryosurgery, argon beam, laser, complications, and death were used in the search.ResultsA review of the literature shows that the performance of the energy devices depends upon the type of procedure. There is no consensus as to which device is optimal for a given procedure. The technical skill level of the surgeon and the knowledge about the devices are both important factors in deciding safe outcomes.ConclusionsAs new energy devices enter the market increases, surgeons should be aware of their indicated use in laparoscopic, endoscopic, and open surgery.

Multidisciplinary Approach for Developing a New Minimally Invasive Surgical Robotic System

The synergy between fundamental science, engineering and medicine is constantly evolving while providing physicians with better tools and techniques for delivering patients effective health care. Minimally invasive surgery (MIS) revolutionized the way in which a number of surgical procedures are performed resulting in quicker postoperative recovery times. Surgical robotics provides a new paradigm to further improve MIS interventions. As part of an extensive experimental protocol, the kinematics and the dynamics of MIS tools were acquired from 30 surgeons who performed seven different minimally invasive surgical tasks. These tasks included tissue manipulation, tissue dissection and suturing in-vivo while using the Blue Dragon system and a porcine model. This database served as a design specification for a kinematic optimization of a spherical surgical robotic manipulator. Following the optimization that determined key geometrical dimensions of the robot, a 7-DOF cable-actuated surgical manipulator was designed and integrated, providing all the degrees of freedom of manual MIS as well as wrist joints located at the surgical end-effector. The surgical robotic system is teleoperated utilizing a single bi-directional UDP socket via a remote master device. This multidisciplinary approach of designing and optimizing the surgical robotic system will lead to a seamless integration into the operating room of the future

Virtual Coupling Schemes for Position Coherency in Networked Haptic Environments

In networked haptic environments, multiple users remotely collaborate sharing the same virtual space. Such environments are used in surgical simulation training, maintenance task training, etc. Maintaining position coherency between the copies of the virtual object in these environments is necessary to achieve consistency in collaboration, especially in the presence of time delays between users. Client-server architecture is widely used to maintain position coherency in networked haptic environments. Such methods introduce a round trip delay for each user and also the collaboration depends on the clients ability to maintain communication with the server. In peer-to-peer architecture where the information from each user is multicasted to all other users, time delay is reduced to half compared to client-server based methods. It is also the most difficult method for maintaining position coherency. Of the three virtual coupling schemes introduced to maintain position coherency in this paper, two utilize a peer-to-peer architecture. The performance of the schemes using peer-to-peer architecture for constant time delays was compared to the virtual coupling scheme representing the client-server method. Experimental results demonstrate that one of the virtual coupling schemes has a comparable performance to the server-based method

Experimental Internet Haptic Collaboration using Virtual Coupling Schemes

In this paper we present the results from several global-scale haptic collaboration experiments that were performed using the Internet. These experiments consist of three virtual coupling schemes proposed to maintain position coherency in a networked haptic virtual environment (NHVE). We compared two of our virtual coupling schemes - which represent a peer-to-peer architecture - to the third - with a client-server architecture. We set up a packet reflector network at our collaborator servers (Italy, Canada and North Carolina, USA) to perform the experiments with subjects located within the same laboratory. Our largest one-way latency was in the order of 200 ms for the packet reflector situated in Italy. The virtual coupling parameters were chosen so that it resulted in stable operation for all the delay values that were tested. User datagram protocol (UDP) was used for haptic data communication because of the high transmission rate requirement for NHVEs. There were three experiments carried out in total: two of them at the packet transmission rate of 1000 Hz with a change in the virtual coupling parameters in scheme 2, and the third one, which tested the three virtual coupling schemes at two fixed transmission rates of 500 Hz and 100 Hz. Locally, the haptic update rate was maintained at 1000 Hz during all the experiments. Our results demonstrate that the peer-to-peer virtual coupling schemes can be used for maintaining position coherency in a NHVE. We also show that the position error and the force rendered to the users increase with the reduction in the packet transmission rate. Given that these experiments were performed through the actual Internet, this work proves valuable for global-scale stable haptic collaboration using the Internet.

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.

Plugfest 2009: Global interoperability in Telerobotics and telemedicine

Despite the great diversity of teleoperator designs and applications, their underlying control systems have many similarities. These similarities can be exploited to enable inter-operability between heterogeneous systems. We have developed a network data specification, the Interoperable Telerobotics Protocol, that can be used for Internet based control of a wide range of teleoperators. In this work we test interoperable telerobotics on the global Internet, focusing on the telesurgery application domain. Fourteen globally dispersed telerobotic master and slave systems were connected in thirty trials in one twenty four hour period. Users performed common manipulation tasks to demonstrate effective master-slave operation. With twenty eight (93%) successful, unique connections the results show a high potential for standardizing telerobotic operation. Furthermore, new paradigms for telesurgical operation and training are presented, including a networked surgery trainer and upper-limb exoskeleton control of micro-manipulators.

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.

Preliminary Face and Construct Validation Study of a Virtual Basic Laparoscopic Skill Trainer

BACKGROUND The Virtual Basic Laparoscopic Skill Trainer (VBLaST) is a developing virtual-reality-based surgical skill training system that incorporates several of the tasks of the Fundamentals of Laparoscopic Surgery (FLS) training system. This study aimed to evaluate the face and construct validity of the VBLaST system. MATERIALS AND METHODS Thirty-nine subjects were voluntarily recruited at the Beth Israel Deaconess Medical Center (Boston, MA) and classified into two groups: experts (PGY 5, fellow and practicing surgeons) and novice (PGY 1-4). They were then asked to perform three FLS tasks, consisting of peg transfer, pattern cutting, and endoloop, on both the VBLaST and FLS systems. The VBLaST performance scores were automatically computed, while the FLS scores were rated by a trained evaluator. Face validity was assessed using a 5-point Likert scale, varying from not realistic/useful (1) to very realistic/useful (5). RESULTS Face-validity scores showed that the VBLaST system was significantly realistic in portraying the three FLS tasks (3.95 +/- 0.909), as well as the reality in trocar placement and tool movements (3.67 +/- 0.874). Construct-validity results show that VBLaST was able to differentiate between the expert and novice group (P = 0.015). However, of the two tasks used for evaluating VBLaST, only the peg-transfer task showed a significant difference between the expert and novice groups (P = 0.003). Spearman correlation coefficient analysis between the two scores showed significant correlation for the peg-transfer task (Spearman coefficient 0.364; P = 0.023). CONCLUSIONS VBLaST demonstrated significant face and construct validity. A further set of studies, involving improvement to the current VBLaST system, is needed to thoroughly demonstrate face and construct validity for all the tasks.

Bilateral teleoperation with time delay using modified wave variable based controller

Force-reflecting teleoperators in which the remote environment is kinesthetically coupled to the operator can considerably increase task performance. Wave-variable-based controllers can support the stable operation of force-reflecting teleoperators under arbitrary communication delays. Transparency in such systems is compromised in order to maintain stability. We had previously proposed a modified wave variable controller that implemented additional wave impedance in the wave variable transformations in order to focus more closely on force tracking. In this paper, we present a new controller for bilateral teleoperators based on the modified wave variable control method which provides superior position and force tracking performance compared to the traditional wave-variable-based method. Moreover, the method has high stability. Theoretical investigation and experimental results confirm the performance of this new controller.