Thomas P. Low

Evaluation of Teleoperated Surgical Robots in an Enclosed Undersea Environment

The ability to support surgical care in an extreme environment is a significant issue for both military medicine and space medicine. Telemanipulation systems, those that can be remotely operated from a distant site, have been used extensively by the National Aeronautics and Space Administration (NASA) for a number of years. These systems, often called telerobots, have successfully been applied to surgical interventions. A further extension is to operate these robotic systems over data communication networks where robotic slave and master are separated by a great distance. NASA utilizes the National Oceanographic and Atmospheric Administration (NOAA) Aquarius underwater habitat as an analog environment for research and technology evaluation missions, known as NASA Extreme Environment Mission Operations (NEEMO). Three NEEMO missions have provided an opportunity to evaluate teleoperated surgical robotics by astronauts and surgeons. Three robotic systems were deployed to the habitat for evaluation during NEEMO 7, 9, and 12. These systems were linked via a telecommunications link to various sites for remote manipulation. Researchers in the habitat conducted a variety of tests to evaluate performance and applicability in extreme environments. Over three different NEEMO missions, components of the Automated Endoscopic System for Optimal Positioning (AESOP), the M7 Surgical System, and the RAVEN were deployed and evaluated. A number of factors were evaluated, including communication latency and semiautonomous functions. The M7 was modified to permit a remote surgeon the ability to insert a needle into simulated tissue with ultrasound guidance, resulting in the worlds first semi-autonomous supervisory-controlled medical task. The deployment and operation of teleoperated surgical systems and semi-autonomous, supervisory-controlled tasks were successfully conducted.

Biologically inspired hexapedal robot using field-effect electroactive elastomer artificial muscles

Small, autonomous mobile robots are needed for applications such as reconnaissance over difficult terrain or internal inspection of large industrial systems. Previous work in experimental biology and with legged robots has revealed the advantages of using leg actuators with inherent compliance for robust, autonomous locomotion over uneven terrain. Recently developed field-effect electroactive elastomer artificial muscle actuators offer such compliance as well as attractive performance parameters such as force/weight and efficiency, so we developed a small (670 g) six-legged robot, FLEX, using AM actuators. Electrically, AM actuators are a capacitive, high-impedance load similar to piezoelectrics, which makes them difficult to rive optimally with conventional circuitry. Still, we were able to devise a modular, microprocessor-based control system capable of driving 12 muscles with up to 5,000 V, operating form an on- board battery. The artificial muscle actuators had excellent compliance and peak performance, but suffered from poor uniformity and degradation over time. FLEX is the first robot of its kind. While there is room for improvement in some of the robot systems such as actuators and their drivers, this work has validated the idea of using artificial muscle actuators in biologically inspired walking robots.

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.

Acceleration compensation for vehicle based telesurgery on earth or in space

Current telesurgical robotic systems are designed to be used exclusively in stationary environments. The ability of a robotic master and slave system to monitor and correct for acceleration induced movement errors would enable conduct of delicate medical procedures onboard moving vehicles. Such operations, without compensation, would be complicated by unintended movement of the surgeonpsilas hands and master controls, causing potentially dangerous response of the surgical robot manipulators. In caring for astronauts on long haul interplanetary missions, it is essential to compensate for alterations in gravitational acceleration when delivering telesurgical or autonomous robotic therapy in the microgravity of space or on non-terrestrial planetary surfaces. This paper introduces new work focused on compensating for unintended master and slave manipulator motion resulting from accelerations of the environment within which they are operated. Experimental results from vehicular operation show how induced motion can be reduced by introduction of dynamic electronic balancing of the master manipulator device and the addition of variable damping proportional to vehicle acceleration. A surgical master console and robot were operated in the micro-gravity and variable gravity of the NASA C-9 airborne parabolic laboratory. Robot kinematics data and surveys of surgeon and astronaut users show that compensating for different gravitational conditions improves usability of the system. Further experiments using an elevator as a motion platform demonstrate the effectiveness of acceleration compensation.