Medical telerobotic systems provide a framework for performing interventional and diagnostic procedures remotely utilizing communication networks. Over the past decade, various systems have demonstrated the feasibility and the significance of telerobotics, some of which have been already adopted in clinical practice. In this study, we elaborate on the potential and discuss associated challenges focusing on the enabling technologies, namely robotic manipulation, telecommunications, and vision systems. A case study of an end-to-end mobile teleechography software platform using the MELODY robotic system is presented, investigating the capability of commercially available 4G (and beyond) wireless networks to communicate clinically lossless medical video for remote diagnosis purposes. Performance analysis demonstrates that medical video transmission approaching the clinical standards of in-hospital examination while conforming to strict delay requirements is achievable.

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 robot's 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 robot's end effector for a better tele-operated control. These combined strategies provide the expert with an improved interactive tool for a tele-diagnosis.

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 robot's 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.

This paper presents two approaches developed to control our CyCab mobile robot. The first one introduces the notion of virtual axle to determine a flat Inverse Kinematics Model; the second one, based on the Escape Lanes method, uses the Direct Kinematics Model. In the last part of this paper, a comparison between the two methods is carried out in order to validate the inverse model and to discuss the two methods respective advantages.

In this paper, we present a control architecture based on the concept of levels. The architecture is composed of two parts called the decision part and the perception part. This organization permits to construct various configurations and is adaptable to any application. We implemented this architecture on different robotic platforms: a mobile robot, an omnidirectional robot and medical one. We focused on the generic aspect of the architecture which has the characteristic to include the tele-operation modes.

This article addresses the omni directional mechanical architectures problematic for mobile robots using 3 motorized axles with 2 spherical orthogonal wheels. These wheels transmit a power torque according to a direction and are completely free with respect to the two others. They are used on 2 mechanical structures: SM1 and SM2. The complete kinematic study emphasizes the facility of controlling such omni-directional robots, and examines the problems involved in the transition of the wheel-to-floor contact on each axle. From this double study emerges an optimal theoretical architecture, but difficult to realize mechanically. We then present a controller which compensates for the errors related to the simplest mechanical structure; and it is validated on a mobile robot ROMNI using mechanical structure SM1

This paper presents a tele-operated robot built within the OTELO European project framework. This six degree-of-freedom non-redundant probe-holder robot with a remote center of motion is dedicated to robotized medical tele-echography. The mechanical structure, chosen by end-users' specifications, presents a self-motion singularity within the working space of the medical expert. A strategy has been developed to counter the effect of the singularity located in the centre of the working space based on an real-time singularity control of the robotic tele-operated system. Thanks to the implementation of this real-time control, several clinical tele-echography tests have been successfully performed where medical specialists were able to propose a diagnosis in 80% of the studied cases.

This paper presents a new tele-operated robotic chain for real-time ultrasound image acquisition and medical diagnosis. This system has been developed in the frame of the Mobile Tele-Echography Using an Ultralight Robot European Project. A light-weight six degrees-of-freedom serial robot, with a remote center of motion, has been specially designed for this application. It holds and moves a real probe on a distant patient according to the expert gesture and permits an image acquisition using a standard ultrasound device. The combination of mechanical structure choice for the robot and dedicated control law, particularly nearby the singular configuration allows a good path following and a robotized gesture accuracy. The choice of compression techniques for image transmission enables a compromise between flow and quality. These combined approaches, for robotics and image processing, enable the medical specialist to better control the remote ultrasound probe holder system and to receive stable and good quality ultrasound images to make a diagnosis via any type of communication link from terrestrial to satellite. Clinical tests have been performed since April 2003. They used both satellite or Integrated Services Digital Network lines with a theoretical bandwidth of 384 Kb/s. They showed the tele-echography system helped to identify 66% of lesions and 83% of symptomatic pathologies.

In this paper, we present a modular method of environment perception for a mobile robot by local mapping. This map building process is done in order to authorize the motions of a mobile robot in unknown indoor environment. To validate it, we have implemented a reactive navigation on a mobile robot which perceives its near environment with two range finders. The map building process is the cluster of several functions: sort of measures in subsets, model of these subsets, elaboration of a map, and updating it with previous measures. Furthermore this process must be quick and sufficiently robust to deliver in real time a safe map to the robot.

An autonomous mobile robot needs externals sensors for its own localization and modeling environment. In order to perform the angular precision of ultrasonic sensor and to improve the number of informations for a given time, we developed an ultrasonic sensor network using the multiple receivers mode. In this paper we introduce the ultrasonic network with its hardware architecture and its functioning mode. We also present a method to localize an echo source with the multiple receivers mode and show how to simply model this echo in the robot frame. We then describe the extraction of environment primitives (segment) by the inertia matrix and Hough transform. Finally, we validate the all process by experiments.