Analyse quantitative d'un volume image par angioscopie virtuelle

- Dans le domaine vasculaire, la connaissance précise des paramètres géométriques des artères et de leurs lésions est nécessaire au diagnostic préopératoire et au choix d'outils endovasculaires adaptés. Au delà de l'instrument de visualisation, l'angioscopie virtuelle doit constituer un outil d'exploration et d'analyse quantitative des structures vasculaires pour le diagnostic, la plannification et l'assistance de l'acte interventionnel. Nous présentons ici une extension géométrique et fonctionnelle du modèle de l'endoscope virtuel, lui permettant de réaliser, au cours de la navigation exploratoire virtuelle et suivant l'axe des structures anatomiques, l'extraction adaptative, opérateur-indépendante et précise de la surface interne des vaisseaux, en particulier en présence de lésions. L'évaluation de l'analyse quantitative de lésions vasculaires par angioscopie virtuelle dans un volume image TDM a été réalisée sur un modèle animal de resténose hyperplasique

AngioNavigation (contribution des environnements virtuels aux interventions endovasculaires assistées par ordinateur)

Dans le contexte de la chirurgie des tissus mous, nous proposons un système de navigation afin de sécuriser les gestes endovasculaires minimalement invasifs. Exploitant un pré-planning fondé sur l'exploration virtuelle d'un volume image préopératoire, l'approche proposée inclut : la conception d'un environnement virtuel spécifique-patient (EV) à vocation pré- et peropératoire, la mise en correspondance de cet EV et de l'environnement interventionnel par recalage 3D TDM / angiographie 2D intégrant des connaissances à priori, le suivi et la localisation 3D des outils endovasculaires, la mise à jour des informations préopératoires prenant en compte les déformations des tissus, et la visualisation d'informations réelles et virtuelles fusionnées par une interface de réalité mixte. Après une évaluation sur simulations et fantômes, un démonstrateur du système a été utilisé dans le bloc opératoire au cours d'interventions endovasculaires réalisées dans les conditions cliniques.RENNES1-BU Sciences Philo (352382102) / SudocSudocFranceF

Ray casting with "on-the-fly" region growing: 3-D navigation into cardiac MSCT volume.

International audienceThis paper describes an extended ray casting scheme for three-dimensional (3-D) navigation into the heart cavities for preoperative planning using multislice X-ray computed tomography data. The key benefit is that artifacts due to contrast inhomogeneities can be eliminated during volume traversal, thus improving the visual perception of the endocardial wall

Depth-map-based scene analysis for active navigation in virtual angioscopy.

This paper presents a new approach dealing with virtual exploratory navigation inside vascular structures. It is based on the notion of active vision in which only visual perception drives the motion of the virtual angioscope. The proposed fly-through approach does not require a premodeling of the volume dataset or an interactive control of the virtual sensor during the fly-through. Active navigation combines the on-line computation of the scene view and its analysis, to automatically define the three-dimensional sensor path. The navigation environment and the camera-like model are first sketched. The basic stages of the active navigation framework are then described: the virtual image computation (based on ray casting), the scene analysis process (using depth map), the navigation strategy, and the virtual path estimation. Experimental results obtained from phantom model and patient computed tomography data are finally reported

Güç-yoğun Dar Toleranslı Kaynak Yöntemlerinin Endüstriyel İmalata Adaptasyonuna Yönelik 4 Eksenli Manipulator Tasarımı ve Bütünlenmesi

Büyük kütlelere sahip endüstriyel yapı ve ekipmanların kaynaklı imalatlarında, kaynak işleminden önce bir ön-montaj süreci söz konusudur. Bir araya getirilen alt-bütünler, bu ön-montaj aşamasının ardından kaynak marifetiyle kalıcı olarak bütünlenmektedirler. Parça hazırlama ve ön-montaj süreçleri yalnızca geleneksel ark kaynak yöntemlerinin uygulanabilirliğine fırsat veren ölçüsel kaçıklıklar içermektedir. Bu mertebedeki ölçüsel kaçıklıklar yeni geliştirilmiş yüksek verimli ve ileri kaynak yöntemlerinin endüstriyel imalat ve montaj alanlarında kullanımını sınırlamaktadır. ArGe ekibimiz BAP-08-11-2013-032 kapsamında yürüttüğü çalışmalarla İleri Kaynak Teknolojileri Laboratuvar’ımızda endüstriyel bir robot manüplatöre bütünlenmiş hibrit plazma ark kaynağı ve CCD-Laser görüntüleme sistemleri ile değişen birleştirme kenar geometrisine bağlı olarak kaynak gücü, hızı ve torç hareketini gerçek zamanlı olarak ayarlayabilen bir kaynak sistemini çalışır hale getirmek üzeredir. Bu projede ise dijital iletişim altyapısı olan ve servo-mekanizmalar marifetiyle 6 eksende hareket kabiliyetine sahip bir endüstriyel robota entegre edilebilen gerçek zamanlı proses kontrol sistemimizin, AC sürücüler de barındıran ve analog iletişim arayüzleri olan konvansiyonel 3 eksenli bir kolon-bom manipülatöre entegre edilirliğinin sağlanması hedeflenmektedir

Characterization of the co-seismic pattern and slip distribution of the February 06, 2023, Kahramanmaraş (Turkey) earthquakes (Mw 7.7 and Mw 7.6) with a dense GNSS network

Two consecutive earthquakes with the magnitudes of Mw 7.7 and 7.6 (February 06, 2023) occurred on the East Anatolian Fault Zone (EAFZ) segments and unfortunately resulted in significant devastation to human life and cities in Turkey and Syria. In this study, we aimed to analyse the co-seismic displacements and fault slip distributions of these seismic events. Our unique high-spatial-resolution Global Navigation Satellite System (GNSS) network (comprising 73 permanent GNSS stations and 40 campaign observation sites), providing the recent geodetic dataset for the region, allows better constraint of the co-seismic surface displacements and slip distributions of both earthquakes. The three largest total displacements were identified as 466 cm, 362 cm, and 360 cm. The Fault interactions along the EAFZ were obvious during the consecutive earthquakes. The ruptures mainly occurred in the left-lateral components of the fault segments, with the maximum slips of 7.25 m and 9.43 m for the first event along the EAFZ and the second event on the Çardak Fault, respectively

Angiovision: Aortic stent-graft placement by augmented angionavigation.

International audienc