50 research outputs found
ToolNet: Holistically-Nested Real-Time Segmentation of Robotic Surgical Tools
Real-time tool segmentation from endoscopic videos is an essential part of
many computer-assisted robotic surgical systems and of critical importance in
robotic surgical data science. We propose two novel deep learning architectures
for automatic segmentation of non-rigid surgical instruments. Both methods take
advantage of automated deep-learning-based multi-scale feature extraction while
trying to maintain an accurate segmentation quality at all resolutions. The two
proposed methods encode the multi-scale constraint inside the network
architecture. The first proposed architecture enforces it by cascaded
aggregation of predictions and the second proposed network does it by means of
a holistically-nested architecture where the loss at each scale is taken into
account for the optimization process. As the proposed methods are for real-time
semantic labeling, both present a reduced number of parameters. We propose the
use of parametric rectified linear units for semantic labeling in these small
architectures to increase the regularization ability of the design and maintain
the segmentation accuracy without overfitting the training sets. We compare the
proposed architectures against state-of-the-art fully convolutional networks.
We validate our methods using existing benchmark datasets, including ex vivo
cases with phantom tissue and different robotic surgical instruments present in
the scene. Our results show a statistically significant improved Dice
Similarity Coefficient over previous instrument segmentation methods. We
analyze our design choices and discuss the key drivers for improving accuracy.Comment: Paper accepted at IROS 201
Control of a hybrid robotic system for computer-assisted interventions in dynamic environments
International audiencePurpose Minimally invasive surgery is becoming the standard treatment of care for a variety of procedures. Surgeons need to display a high level of proficiency to overcome the challenges imposed by the minimal access. Especially when operating on a dynamic organ, it becomes very difficult to align instruments reliably and precisely. In this paper, a hybrid ro-botic system and a dedicated robotic control approach are proposed to assist the surgeon performing complex surgical gestures in a dynamic environment. Methods The proposed hybrid robotic system consists of a rigid robot arm on top of which a continuum robot is mounted in series. The continuum robot is locally actuated with McKibben muscles. A control scheme is adopted based on quadratic programming framework. It is shown that this framework allows enforcing a set of constraints on the pose of the tip, as well as of the instrument shaft, which is commanded to slide in and out through the entry point. Results Through simulation and experiments it is shown how the robot tool-tip is able to follow sinus-oidal trajectories of 0.37 Hz and 2 Hz, corresponding to motion due to breathing and heartbeat respectively, while maintaining the instrument shaft pivoting nicely about the entry point. The positioning and tracking accuracy of such system is shown to lie below 3mm in position and 5 âą in angle. Herbert De Praetere is with UZ Leuven, Cardiac surgery, Conclusion The results suggest a good potential for applying the proposed technology to assist the surgeon during complex robot-assisted interventions. It is also illustrated that even when using flexible hence relatively safe end-effectors, it is possible to reach acceptable tracking behaviour at relatively high frequencies
Design and Control of Continuum Robots for Minimally Invasive Surgical Applications
Flexible robots are a rapidly expanding research field. From industrial to exploration applications, flexible robots can provide significant benefits compared to conventional robots. Their properties are also appealing for the development of surgical instrumentation. Thanks to their superior dexterity these devices can reach places that are otherwise inaccessible to the surgeon, paving the way for new and less invasive interventions. However, continuum robots require radically different controllers from those used in conventional rigid robots (rigid vs. compliant â localized joints vs. continuum deformation). In addition, in minimally invasive surgeries, the robotâs environment is invariably complex and deformable. The robot can thus not be treated isolated from its environment. This thesis investigates the design and control of flexible continuum robots for minimally invasive surgical applications.status: publishe
Résultats de la mise en oeuvre des réseaux REPHY (Réseau Phytoplancton et Phycotoxines) et SRN (Suivi Régional des Nutriments) - Zones cÎtiÚres de la Manche orientale et de la baie sud de la Mer du Nord - Bilan de l'année 2021
The coastal zone of the Nord â Pas-de-Calais / Picardie showed dysfonctioning patterns of the ecosystem considered to be link to human activities along shores. These results in regular massive development of species, such as the phytoplanktonic seaweed, Phaeocystis sp. which life cycle was partly linked to nutrients availability and consequently to anthropogenic inputs. As part of the evaluation of the influence of continental inputs on the marine environment (nitrates, phosphates,âŠ) and on potential eutrophication processes, of the estimation of the efficiency of the sewage treatments plants in the possible elimination of dumpings and in order to establish a long-term survey to follow up the change in coastal waters quality, the regional nutrients monitoring network was implemented by Ifremer in collaboration with the Agence de l'Eau Artois-Picardie in 1992 in order to complete the REPHY (Phytoplankton and Phycotoxins) monitoring programme. This study reports the main results for the year 2021 in terms of temporal change of the main physico-chemical and biological parameters characteristic of water masses sampled along three transects offshore Dunkerque, Boulogne-sur-Mer and the Bay of Somme.Le littoral Nord - Pas-de-Calais / Picardie montre de nombreux signes de dysfonctionnements induits principalement par lâactivitĂ© anthropique. Ces signes se manifestent presque toujours par un dĂ©sĂ©quilibre des populations, quâelles soient animales ou vĂ©gĂ©tales. En effet, certaines espĂšces dominent. Câest le cas de la PrymnesiophycĂ©e Phaeocystis sp., une algue phytoplanctonique naturelle qui prolifĂšre tous les ans au printemps. Le cycle de dĂ©veloppement de lâespĂšce Ă©volue depuis quelques annĂ©es (modification de lâamplitude, de la durĂ©e et de lâextension graphique du bloom) et est fortement liĂ© Ă la dynamique des sels nutritifs comme les nitrates et les phosphates par exemple. Dans le cadre de lâĂ©valuation de lâinfluence des apports continentaux en Ă©lĂ©ments nutritifs sur dâĂ©ventuels processus dâeutrophisation du milieu marin, de lâestimation de lâefficacitĂ© des stations dâĂ©puration Ă Ă©liminer de telles substances et afin dâĂ©tablir un suivi Ă long terme permettant de suivre lâĂ©volution de la qualitĂ© des eaux littorales, le rĂ©seau de Suivi RĂ©gional des Nutriments (SRN) a Ă©tĂ© mis en place par lâIfremer en collaboration avec lâAgence de lâEau Artois-Picardie en 1992 afin de complĂ©ter le rĂ©seau REPHY (RĂ©seau Phytoplancton et Phycotoxines). Ce rapport prĂ©sente les principaux rĂ©sultats de lâannĂ©e 2021 en termes dâĂ©volution temporelle des paramĂštres physico-chimiques et biologiques caractĂ©ristiques des masses dâeaux Ă©chantillonnĂ©es au niveau des points de surveillance de trois radiales situĂ©es Ă Dunkerque, Ă Boulogne-sur-Mer et en Baie de Somme
Contributions des mesures automatisées à haute fréquence de type FerryBox pour les programmes thématiques Eutrophisation et Habitats Pélagiques de la DCSMM. Campagnes 2018
Dans le cadre du programme de surveillance des descripteurs DCSMM 1HP et 5, un suivi saisonnier des paramĂštres physico-chimiques et biologiques liĂ©s Ă ces descripteurs a Ă©tĂ© mis en place Ă lâĂ©chelle des SRM Manche Mer du Nord et Mer Celtique en 2018. Ce suivi implique les campagnes halieutiques optimisĂ©es IBTS et CGFS ainsi que 2 campagnes dĂ©diĂ©es DCSMM dĂ©ployĂ©es par le CNRS dont la stratĂ©gie dâĂ©chantillonnage pour le D5 et D1HP a Ă©tĂ© proposĂ©e dans un prĂ©cĂ©dent rapport. Parmi les outils dĂ©ployĂ©s lors de ces campagnes saisonniĂšres, les outils de mesures Hautes FrĂ©quences automatisĂ©s de type FerryBox ont Ă©tĂ© proposĂ©s comme complĂ©ment aux mĂ©thodes conventionnelles Basses FrĂ©quences dont les donnĂ©es alimentent les indicateurs DCSMM. Lâutilisation de ces outils a Ă©tĂ© validĂ©e lors dâune campagne dâessais techniques Ă bord du N/O Thalassa. Les analyses des donnĂ©es HF mesurĂ©es lors des diffĂ©rentes campagnes en 2018 montrent une rĂ©partition spatiale des mesures trĂšs variable selon les paysages marins. Certains paysages marins nĂ©cessiteraient une meilleure couverture spatiale des mesures HF. Les mailles labellisĂ©es DCSMM sont Ă©galement insuffisamment Ă©chantillonnĂ©es. La caractĂ©risation des masses dâeau par classification spectrale des mesures HF montre une bonne correspondance avec les paysages marins ce qui permettra une meilleure prise en compte des paramĂštres biologiques et biogĂ©ochimiques
Résultats de la mise en oeuvre des réseaux REPHY (Réseau Phytoplancton et Phycotoxines) et SRN (Suivi Régional des Nutriments). Zones cÎtiÚres de la Manche orientale et de la baie sud de la Mer du Nord. Bilan de l'année 2020
The coastal zone of the Nord â Pas-de-Calais / Picardie showed dysfonctioning patterns of the ecosystem considered to be link to human activities along shores. These results in regular massive development of species, such as the phytoplanktonic seaweed, Phaeocystis sp. which life cycle was partly linked to nutrients availability and consequently to anthropogenic inputs. As part of the evaluation of the influence of continental inputs on the marine environment (nitrates, phosphates,âŠ) and on potential eutrophication processes, of the estimation of the efficiency of the sewage treatments plants in the possible elimination of dumpings and in order to establish a long-term survey to follow up the change in coastal waters quality, the regional nutrients monitoring network was implemented by Ifremer in collaboration with the Agence de l'Eau Artois-Picardie in 1992 in order to complete the REPHY (Phytoplankton and Phycotoxins) monitoring programme. This study reports the main results for the year 2020 in terms of temporal change of the main physico-chemical and biological parameters characteristic of water masses sampled along three transects offshore Dunkerque, Boulogne-sur-Mer and the Bay of Somme.Le littoral Nord - Pas-de-Calais / Picardie montre de nombreux signes de dysfonctionnements induits principalement par lâactivitĂ© anthropique. Ces signes se manifestent presque toujours par un dĂ©sĂ©quilibre des populations, quâelles soient animales ou vĂ©gĂ©tales. En effet, certaines espĂšces dominent. Câest le cas de la PrymnesiophycĂ©e Phaeocystis sp., une algue phytoplanctonique naturelle qui prolifĂšre tous les ans au printemps. Le cycle de dĂ©veloppement de lâespĂšce Ă©volue depuis quelques annĂ©es (modification de lâamplitude, de la durĂ©e et de lâextension graphique du bloom) et est fortement liĂ© Ă la dynamique des sels nutritifs comme les nitrates et les phosphates par exemple. Dans le cadre de lâĂ©valuation de lâinfluence des apports continentaux en Ă©lĂ©ments nutritifs sur dâĂ©ventuels processus dâeutrophisation du milieu marin, de lâestimation de lâefficacitĂ© des stations dâĂ©puration Ă Ă©liminer de telles substances et afin dâĂ©tablir un suivi Ă long terme permettant de suivre lâĂ©volution de la qualitĂ© des eaux littorales, le rĂ©seau de Suivi RĂ©gional des Nutriments (SRN) a Ă©tĂ© mis en place par lâIfremer en collaboration avec lâAgence de lâEau Artois-Picardie en 1992 afin de complĂ©ter le rĂ©seau REPHY (RĂ©seau Phytoplancton et Phycotoxines). Ce rapport prĂ©sente les principaux rĂ©sultats de lâannĂ©e 2020 en termes dâĂ©volution temporelle des paramĂštres physico-chimiques et biologiques caractĂ©ristiques des masses dâeaux Ă©chantillonnĂ©es au niveau des points de surveillance de trois radiales situĂ©es Ă Dunkerque, Ă Boulogne-sur-Mer et en Baie de Somme
First Comprehensive Quantitative Multi-Parameter Assessment of the Eutrophication Status from Coastal to Marine French Waters in the English Channel, the Celtic Sea, the Bay of Biscay, and the Mediterranean Sea
The first quantitative and comprehensive assessment of the eutrophication status from coastal to offshore French waters was performed within the Marine Strategy Framework Directive (MSFD descriptor 5) for the English Channel, the southern bight of the North Sea, the Celtic Seas, the Bay of Biscay and the Western Mediterranean Sea. Based on a combination of different data sources (in situ, satellite, and modeling products), a fully-integrated dataset was generated over the period 2010â2016. Using the best available knowledge on the eutrophication process and definition, the assessment procedure was implemented considering nutrient pressures, and direct and indirect effects of excessive inputs. The different steps of the assessment were: (i) Establishment of assessment levels and thresholds, (ii) development of methodology for aggregation and integration of data, and (iii) qualification of the Environmental Status. We investigated how reliable this assessment procedure was when considering other complementary information. Results highlighted that, despite efforts in recent decades to reduced nutrient inputs, the pressure on coastal marine ecosystems was still high. We discuss options for improving the coherence between MSFD and other similar approaches and associated monitoring programs. This study identifies areas where an increased monitoring effort is needed to improve the assessment and where environmental management actions are of priority