Impedance controller and its clinical use of the remote ultrasound diagnostic system

A master-slave type remote ultrasound diagnostic system was developed. This paper presents and evaluates its control strategy. There is only one impedance controller that is located in the master site or the slave site or the relay point in the conventional impedance controller. Therefore, the effect of the time lag in transmitting force and position data becomes large in the conventional system. Then we propose an impedance controller to cope with this problem. In the proposed system, the position controller for the slave manipulator is also constructed by means of a velocity-control-based impedance controller. This feature makes it possible to shorten the dead time taken by the slave manipulator to respond for the contact force input. This paper also reports the result of a clinical use of the remote ultrasound diagnostic system. The result of the experiments demonstrates that a medical doctor can diagnose patients as well as the conventional diagnosis.