Improvement of Tactile Sensation of a Bilateral Forceps Robot by a Switching Virtual Model

Abstract

Interest in tele-operation started many decades ago. Today, tele-operation is becoming a reality with improved tele-communication systems. Bilateral control is also a subset of tele-operation. Usually in bilateral control, force position information is exchanged between a master and a slave. This structure successfully transmits tactile sensation from the slave environment to the master operator. A bilateral control system is capable of transmitting tactile sensation to the master side. This capability is also known as the transparency of the system. If bilateral control is used in a surgery, ideally the medical doctor should sense the feeling coming from the body tissue together with the reaction force of the special surgical tool. We have previously proposed a method to eliminate the special surgical tool with a simple tool tip and a virtual tool model. However, a physical tool as well as the proposed virtual tool add impedance to the system. Even if a virtual model is used, impedances are essential to carry out the tool action. In this paper, a novel method is proposed to switch off and on the virtual tool model when the tool action can be replaced by the environmental reaction forces. An experiment was carried out using a bilaterally controlled forceps robot. Results show the applicability of the idea.

Design and development of sensorless based 5-DOF bilaterally controlled surgical manipulator: A prototype

“…The disturbance observer offers numerous advantages including observation of disturbance torque and compensation. While a regular force sensor consists of narrow bandwidth, the disturbance observer's offers relatively wider bandwidth [22]. The force sensor consisting of narrow bandwidth cannot offer substantial force sensation and is just able to detect wherever it is implemented.…”

“…To control the slave side, torque/position information from the master side is used and vice versa. Thus, it is important to capture the exact torque/position information of the slave to provide high transparency to the master side [17,22]. However, according to control theory, transparency and stability cannot achieve simultaneously for bilateral controllers due to the system and environment uncertainties.…”

Observer based dynamic control model for bilaterally controlled MU-lapa robot: Surgical tool force limiting

“…Virtual spring controller is inserted at master side and force lock is affianced at slave's side. Moreover, with addition of virtual damper control system the absence of position of the actual force that is applied from master manipulator is equalized and is compensated [32]. In this study we are focusing on improving the Operational capability of the Bilaterally Controlled MU-LapaRobot primary surgical tool insertion.…”