Laurence Josserand

A predictive control approach and interactive GUI to enhance distal environment rendering during robotized tele-echography: Interactive platform for robotized telechography

Performing a robotized telemedicine act via specific networks brings forth two issues. One is transparency in order to enable the operator, e.g. the medical ultrasound specialist, to safely and accurately perform bilateral tele-operation tasks despite the long time delays inherent to the communication link. To counter these effects, two strategies are combined to improve, at the operator site, the rendering of the interactions between the remote robotic systems with its environment (i.e. the patient), and the control of the robots orientation. The first approach is the development of a new control architecture based on an internal model providing an anticipated value of the distant environment stiffness; it is complemented with a graphic user interface (GUI) which provides the expert with the real-time relative position of the haptic probe with the robots end effector for a better tele-operated control. These combined strategies provide the expert with an improved interactive tool for a tele-diagnosis.

Closed loop control for a tele-echography system with communication delays

A closed loop control scheme for a tele-echography system with communication delays is here experimentally developed. Nowadays, available tele-echography systems work in an open loop manner, without taking into account the communication delays.We propose here to apply the closed loop approach we previously theoretically developed. First, we briefly recall the key steps of this approach, which use partial differential equations (PDE) modeling of the delays, leading to an infinite dimensional model of the overall tele-operation system that we incorporate in an Internal Model Control (IMC) closed loop structure. We apply it in real-time thanks to a tele-operation testing platform which has been built, so various network and physical parameters are adjustable. It is composed of a master PC and a slave PC, communicating on a WLAN, and of a Phantom device which must track the positions given by a joystick. Finally, this paper shows the results obtained with a basic predictive control tested on the platform.

An Anticipative Control Approach and Interactive GUI to Enhance the Rendering of the Distal Robot Interaction with its Environment during Robotized Tele-Echography: Interactive Platform for Robotized Tele-Echography

Performing a robotized telemedicine act via specific networks brings forth the issue of transparency in order to enable the operator, e.g. the medical ultrasound specialist, to safely and accurately perform bilateral tele-operation tasks despite the long time delays inherent to the communication link. To counter these effects, two strategies are combined to improve, at the operator site, the rendering of the interactions between the remote robotic systems with its environment i.e. the patient, and the control of the robots orientation at the operator site. The first approach is the development of a new control architecture based on an internal model providing an anticipated value of the distant environment stiffness; it is complemented with a graphic user interface GUI which provides the expert with the real-time relative position of the haptic probe with the robots end effector for better tele-operated control. These combined strategies provide the expert with an improved interactive tool for tele-diagnosis.

Direct Model Navigation issue shifted in the continuous domain by a predictive control approach for mobile robots

This paper presents a new navigation method for mobile robots, based on direct kinematics model and predictive control approach. It is adaptable to all types of robots taking into account their specific constraints. The research of the optimal trajectory is shifted in the continuous parameters space, which enables the exploitation of all of the robots capabilities. The use of a stochastic algorithm enables the determination of obstacle bypass trajectories, and simulation results show that the navigation in cluttered environment is improved.

PDE Approach for Time Delays in Robotized Teleoperation

Semigroup and spectrum perturbations are suitable for control synthesis of distributed parameter systems described by partial differential equation (PDE). The representation and processing of delay in tele-operated systems have a major scientific interest. In this contribution, the aim is to show that infinite dimensional representation of the delay by PDE can be suitable for control synthesis where the objective is that the tele-operated system tracks the master system. The Internal Model Boundary Control (IMBC) structure is used to achieve closed loop tele-operated characterization.

MARTE PROJECT : TELE-ECHOGRAPHY BETWEEN KYPEROUNTA AND NICOSIA (CYPRUS)

Ultrasound experts, who are few and not always on hand when needed, have now the tool and the possibility to examine patients from a distance, and thus perform a complete diagnosis without being in the same geographical position with the patient. This is possible thanks to a telemedicine system aiming to provide the possibility to examine a remote patient using a tele-operated controlled robot. In the frame of this project, different validations have been performed to show the technical performances of the teleoperated chain and the repercussions on the clinical aspect. The clinical validation is the crucial part for the validation of the overall concept of tele-echography. Thus, various specialities were investigated all throughout the project life, with the participation of different medical experts from several countries, namely France, Spain and Cyprus.