Development of real-time simulation for workload quantization in robotic tele-surgery

Tele-surgery enables medical care even in a remote region and has been realized in clinical cases by means of a special communication line. To make tele-surgery a commonly employed method, a surgical environment must be realized by means of a public communication line such as the Internet. In this paper, we focus on providing a general-purpose operating environment using public lines such as the Internet, and aim to clarify the optimum conditions of network 'Quality of Service' (QoS) required by robotic tele-surgery, by employing a method using three simulators. We propose an indicator of operability and workload. The proposed simulation system consists of a QoS simulator, organ deformation calculation, and virtual slave manipulators. The operability of two tasks using a rigid body model was evaluated by the semantic differential (SD) method, and the workload of organ model operation was evaluated with NASA-TLX. As a result of these experiments, we determined that the data flow in our proposed tele-surgery system will be controlled when delay exceeds 400 (ms) in the case of rigid body model operation or when the delay exceeds 200 (ms) in the case of organ model operation. The next research step would be to focus on a surgical environment where internal organ models would be integrated into a slave simulation system.