Florent Nageotte

Control of a multiple sections flexible endoscopic system

The use of flexible endoscopes in new surgical procedures such as NOTES, i.e. Natural Orifice Transluminal Endoscopic Surgery, raises many problems. Indeed, the movements of conventional flexible endoscopes are limited and surgeons can only perform basic tasks with these systems. In order to enhance endoscope possibilities and workspace, we are currently developing a robotized system. The prototype we propose is based on the combination of several flexible endoscopes. The kinematic model of the system is detailed in order to develop a method of control. The paper presents the implementation of a control strategy using an external sensor which allows to deal with non linearities induced by the cable mechanism of the endoscopes.

Design of a telemanipulated system for transluminal surgery

Flexible endoscopes have been recently used for new surgical procedures called NOTES, i.e. Natural Orifice Transluminal Endoscopic Surgery. However, the movements of conventional flexible endoscopes are limited and surgeons can only perform basic tasks with these systems. In order to enhance endoscopes possibilities and workspace, several solutions have been proposed to redesign the whole endoscopic system. New devices have been proposed recently which are made up of a classical endoscope basis with two additionnal arms. However, these mechanical devices are not completely adequate to properly perform NOTES. That is why we are currently developing a robotized system which can be simultaneously teleoperated while performing autonomous motions. This article presents the constraints of transluminal surgery, existing devices and our new system together with its mathematical modeling.

Improvements in the control of a flexible endoscopic system

The use of flexible cable-driven systems is common in medicine (endoscope, catheter...). Their flexiblity allows surgeons to reach internal organs through sinuous and constrained ways. Unfortunately these systems are subject to backlash due to their internal mechanism. These non linearities raise many difficulties when robotizing and controlling such systems. In this article we propose an approach to improve the cartesian control of a four ways flexible endoscopic system with strong and unknown backlash-like non linearities. The method is based on an automatic off-line hystereses learning. We show that, despite coupling between degrees of freedom, it is possible to extract information from the hystereses which allow to improve cartesian control. Experiments on a real endoscopic system show the validity and the interest of the approach.

Pose Estimation and Feature Tracking for Robot Assisted Surgery with Medical Imaging

The field of vision-based robotics has been widely growing for more than three decades, and more and more complex 3-D scenes are within robot vision capabilities thanks to better understanding of the scenes, improvement of computer capabilities and control theory. The achievement of applications like medical robotics, mobile robotics, micro-robotic manipulation, agricultural automation or the observation by aerial or underwater robots needs the integration of several research areas in computer vision and automatic control ([32, 19]). For the past two decades, medical robot and computer-assisted surgery have gained increasing popularity. They have expanded the capabilities and comfort for both patients and surgeons in many kinds of interventions such as local therapy, biopsies, tumors detection and removal with techniques like multi-modal registration, online visualization, simulators for specific interventions and tracking. Medical robots provide a significant help in surgery, mainly for the improvement of positioning accuracy and particularly for intra-operative image guidance [36]. The main challenge in visual 3-D tracking for medical robotic purposes is to catch the relevant video information from images acquired with endoscopes [5], ultra-sound probes [17, 21] or scanners [35, 26] so as to evaluate the position and the velocity of objects of interest which usually are natural or artificial landmarks attached to a surgical instrument.

Introducing STRAS: A new flexible robotic system for minimally invasive surgery

In this paper we present a new robotic system, called STRAS, designed for endoluminal and transluminal surgery. The system is based on the Anubis® platform - a manual flexible system designed by Karl Storz for transluminal operations. Our new robot is a modular robotic system, compatible with the medical environment, allowing an easy setup in the operating room. It provides up to 10 Degrees of Freedom (DoFs), enabling the 3D positioning of an endoscopic camera, positioning of two instruments and offering grasper opening / closing functionalities. The paper presents for the first time the mechanical, electrical and control design of STRAS. An initial characterization of the system shows that, because of complex mechanical interactions, the kinematic modeling is not sufficient for cartesian control. However, first experiments, demonstrate that the robotic system can be telemanipulated using joint control and that the robotic system enables a single user to perform complex tasks with the underlying flexible system.

Design of a Robotized Flexible Endoscope for Natural Orifice Transluminal Endoscopic Surgery

Natural orifice transluminal endoscopic surgery (NOTES) is a new surgical technique, which consists in reaching the peritoneal cavity through a natural orifice (mouth, anus, or vagina) in order to treat a specific area (Fig. 1). It allows to perform various procedures such as cholecystectomy or tubal ligation. The main advantage of this kind of surgery is the absence of visible scars since it does not need any external incision. Thanks to this procedure, postoperative pain, recovery time, and psychological impact are reduced. The first transluminal procedure has been performed by Pr. Marescaux in Strasbourg in 2007 [1].

Comparison of methods for estimating the position of actuated instruments in flexible endoscopic surgery

The spatial configuration of actuated flexible instruments is fundamental for control applications in robotic noscar surgery. In these operations, the instruments are inserted in the channels of a flexible guide equipped with an endoscopic camera. In this paper we propose to estimate the position of the instruments of the Anubis platform (Karl Storz) using the endoscopic images provided by the embedded camera. In this system flexible instruments have 3-DOF (translation and rotation in the channel and deflection). Application of standard approaches for 3D location with such system do not provide good accuracy because of uncertainties on several model parameters. To cope with these uncertainties, supervised learning methods has been explored. With the help of colored visual markers attached to the instruments, the proposed approach consists of an image segmentation stage followed by a position estimation stage. Firstly, the markers are segmented in the images using an AdaBoost classifier manually trained on in-vivo images. Subsequently, the resulting blobs are used as input data of an approximation function trained using ground truth information provided by a magnetic sensor. A comparison with two other model-based methods showed the potentialities of such an approach on real devices.

A Novel Telemanipulated Robotic Assistant for Surgical Endoscopy: Preclinical Application to ESD

Objective: Minimally invasive surgical interventions in the gastrointestinal tract, such as endoscopic submucosal dissection (ESD), are very difficult for surgeons when performed with standard flexible endoscopes. Robotic flexible systems have been identified as a solution to improve manipulation. However, only a few such systems have been brought to preclinical trials as of now. As a result, novel robotic tools are required. Methods: We developed a telemanipulated robotic device, called STRAS, which aims to assist surgeons during intraluminal surgical endoscopy. This is a modular system, based on a flexible endoscope and flexible instruments, which provides 10 degrees of freedom (DoFs). The modularity allows the user to easily set up the robot and to navigate toward the operating area. The robot can then be teleoperated using master interfaces specifically designed to intuitively control all available DoFs. STRAS capabilities have been tested in laboratory conditions and during preclinical experiments. Results: We report 12 colorectal ESDs performed in pigs, in which large lesions were successfully removed. Dissection speeds are compared with those obtained in similar conditions with the manual Anubiscope platform from Karl Storz. We show significant improvements (

Endoluminal surgical triangulation 2.0: A new flexible surgical robot. Preliminary pre-clinical results with colonic submucosal dissection

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Robotized High Intensity Focused Ultrasound (HIFU) system for treatment of mobile organs using motion tracking by ultrasound imaging: An in vitro study

). Conclusion: These experiments show that STRAS (v2) provides sufficient DoFs, workspace, and force to perform ESD, that it allows a single surgeon to perform all the surgical tasks and those performances are improved with respect to manual systems. Significance: The concepts developed for STRAS are validated and could bring new tools for surgeons to improve comfort, ease, and performances for intraluminal surgical endoscopy.