Cyril Novales

A tele-operated mobile ultrasound scanner using a light-weight robot

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.

Omni-directional robot with spherical orthogonal wheels: concepts and analyses

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

Robotized Tele-Echography: An Assisting Visibility Tool to Support Expert Diagnostic

This paper presents a robotized tele-echography system with an assisting visibility mode that helps the medical expert diagnosis. This autonomous mode is based on a multitask control approach that maintains the visibility of an anatomic element of interest while the medical expert teleoperates a 2-D ultrasound (US) probe held by a 4-degrees-of-freedom (DOF) robot. The main task is used to automatically maintain several visual constraints that guarantee an intersection between the US image plane and the organ of interest (OI). A secondary task allows the medical expert to manually apply the probe motion through the teleoperation mode. The main advantage of this approach is to give to the clinician the control of all the DOFs of the probe to examine the patient while automatically preserving the visibility of the OI when required. Experimental results, performed on a phantom and a human abdomen, demonstrate the efficiency of the visibility assistance task.

Medical telerobotic systems: Current status and future trends

Teleoperated medical robotic systems allow procedures such as surgeries, treatments, and diagnoses to be conducted across short or long distances while utilizing wired and/or wireless communication networks. This study presents a systematic review of the relevant literature between the years 2004 and 2015, focusing on medical teleoperated robotic systems which have witnessed tremendous growth over the examined period. A thorough insight of telerobotics systems discussing design concepts, enabling technologies (namely robotic manipulation, telecommunications, and vision systems), and potential applications in clinical practice is provided, while existing limitations and future trends are also highlighted. A representative paradigm of the short-distance case is the da Vinci Surgical System which is described in order to highlight relevant issues. The long-distance telerobotics concept is exemplified through a case study on diagnostic ultrasound scanning. Moreover, the present review provides a classification into short- and long-distance telerobotic systems, depending on the distance from which they are operated. Telerobotic systems are further categorized with respect to their application field. For the reviewed systems are also examined their engineering characteristics and the employed robotics technology. The current status of the field, its significance, the potential, as well as the challenges that lie ahead are thoroughly discussed.

A local map building process for a reactive navigation of a mobile robot

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.

Quick primitives extraction using inertia matrix on measures issue from an ultrasonic network

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.

Assistive system based on nerve detection and needle navigation in ultrasound images for regional anesthesia

Assistive system based on ultrasound images analysis and robotics guidance for UGRA.New approach based on machine learning and image processing to identify the nerve.Combination of template matching and active contour to segment the ROIs in US images.Real-time trajectory generation algorithm for guiding the needle.Direct model based method with adaptability to the environment dynamics. The development of Ultrasound-Guided Regional Anesthesia (UGRA) is of great help to practitioners of regional anesthesia as it enables real time visualization of the needle, the targeted nerve, and different anatomic structures. However, the clinician has to perform a complex hand coordination to keep the needle, the nerve and some key regions visible in the ultrasound image plane. Daily clinical practice therefore requires a high degree of training and practical skill to identify the nerve block and steer the needle to it. There are two critical steps in UGRA: the recognition of anatomical structures and steering the needle to the target region. An intelligent system, with the ability to identify the regions of interest and to provide the needle insertion trajectory in ultrasound images, can significantly improve UGRA practice and generalize it to medical facilities that lack practitioners. It would also make the UGRA procedure safer (i.e., reducing the risk of nerve trauma). This work presents the first fully automatic system for the detection of regions of interest and generation of the needle trajectory for UGRA. Several problems were addressed, in two stages. The first one consisted in the automatic localization and segmentation of the nerve (target) and arteries (obstacles) in ultrasound images. A new method based on a machine learning algorithm with a multi-model classification process using a sliding window for localization, then an active contour was applied to delineate the localized regions. In the second stage, an algorithm for path planning was also developed to obtain the optimal trajectory for needle insertion based on the result of the first stage (target and obstacle detection). To check the effectiveness of the proposed system, firstly, experiments were performed over individual modules of the detection framework. Secondly, a comparison between the overall framework and the existing method was performed. Two data-sets were acquired in real conditions at different times to prove the robustness of our method. The first data-set contained eight patients and the second data-set, acquired one year later, contained five patients. Experimental results demonstrate the robustness of the proposed scheme and the feasibility of such an assistive system.

Control robot by a generic control architecture

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.

A hierarchical architecture to control autonomous robots evolving in an unknown environment

This paper addresses the problem of autonomy for mobile robots: on which part of the robot do we act more autonomy. After having modeled a mobile robot - limited to earth surface devices - we present an original mechanical structure that permits to a robot to be omni-directional; the experiments validate it. But the mechanical structure is not the only way to improve autonomy. So we have designed a functional architecture - based on multilevel architectures - to control mobile robots. Using an online local mapping of the environment, we have validated the first steps of this functional architecture on a second mobile robot, more powerful.

Robotic co-manipulation with 6 DoF admittance control: Application to patient positioning in proton-therapy

The paper focuses on controlling by hand a robot carrying a patient lying down on a “couch top” located at the extremity of the end-effector. The Orion prototype, is a six Degree-of-Freedom (DoF) robotic system. The control of the robot is achieved through a home-made co-manipulated haptic device located under the couch top and operated by a paramedical assistant. This device enables the operator to move the couch top, on which the patient lies down, and within an identified operational safety space. The 6 DoF admittance control algorithm is implemented on this new robotic platform. An experimental validation has been carried out to validate the co-manipulation control of the robot. The adaptable admittance parameters have been tuned on several experiments in order to observe the mass-spring-damper equivalent behaviour and demonstrate the validity of the implemented admittance algorithm.