REDUCING LATENCY ISSUES FOR ROBOTIC SURGICAL SYSTEMS IN REMOTE ENVIRONMENTS

A primary limitation that prevents the integration of haptic feedback into telesurgical systems is related to data transmission and latency issues. Prior studies have shown that transmission delays between the master and remote devices greater than 200 ms or that are variable in nature impact surgical precision. Furthermore, latency or data loss can also lead to instabilities in closed loop control reducing the reliability of these remote surgical systems. The proposed system will incorporate a model-based teleoperation system, presently being tested for operation on the ISS “International Space Station”, that activates control strategies for autonomous actions of the surgical robot, thus bridging periods of degraded communication. More Specifically, the team will develop a remote surgical robot, including haptic feedback, with countermeasures to handle signal communication issues, including temporary loss of signal, increased latency, and bandwidth constraints to aid military surgeons during teleoperations. The system is capable of addressing the critical healthcare needs of the military, as follows: 1) the surgical environment can be accessed by remote users, such as experts not present on-site, facilitating on-demand clinical expertise; 2)  Telesurgery that utilizes haptic feedback provides clinicians with valuable feedback about the mechanical properties of tissue that can enhance the controllability of surgical instruments. Based off of previous work with teleoperation of remote satellites, the overall technology objective is to develop a model-based teleoperation system, where a surgeon operates on a virtual model and a patient-side robot follows the actions of the surgeon. In a surgical scenario, the initial model could be created from 3D medical images, such as CT images, or from real-time images, such as x-ray fluoroscopy or ultrasound. The key tasks associated with the proposed work focus on the methods to build and update the model and to provide autonomous actions that enable the system to bridge periods of degraded communication between the master console and remote robot.  In cases of lost or degraded communication, comparisons between the virtual model and patient-side images would be used as a catalyst to activate control strategies for autonomous actions of the surgical robot, thus bridging periods of degraded communication. Implementation of control strategies and autonomous actions could help address real-world latency issues associated with tele-operation in rugged and remote environments.  The strategies would enable predictable control signals to be delivered to the surgical robot thereby preventing unwanted actions during periods of lost communication. The system to be developed would serve as an enabling technology that could help address latency issues associated with tele-surgery, one of the most significant issues impacting surgical robots from being implemented for austere environments.