Compaction behavior of out-of-autoclave prepreg materials

The main challenges with composite parts manufacturing are related to the curing means, mainly autoclaves, the length of their cycles and their operating costs. In order to decrease this dependency, out of autoclave materials have been considered as a solution for high production rate parts such as spars, flaps, etc… However, most out-of-autoclave process do not possess the same maturity as their counterpart, especially concerning part quality1. Some pre-cure processes such as compaction and ply lay-up are usually less of a concern for autoclave manufacturing: the pressure applied during the cycle participates to reduce the potential defects (porosity caused by a poor quality lay-up, bad compaction, entrapped air or humidity…). For out-of-autoclave parts, those are crucial steps which may have many consequences on the final quality of the laminate2. In order to avoid this quality loss, those steps must be well understood

3D tracking of laparoscopic instruments using statistical and geometric modeling

International audienceDuring a laparoscopic surgery, the endoscope can be manipulated by an assistant or a robot. Several teams have worked on the tracking of surgical instruments, based on methods ranging from the development of specific devices to image processing methods. We propose to exploit the instruments' insertion points, which are fixed on the patients abdominal cavity, as a geometric constraint for the localization of the instruments. A simple geometric model of a laparoscopic instrument is described, as well as a parametrization that exploits a spherical geometric grid, which offers attracting homogeneity and isotropy properties. The general architecture of our proposed approach is based on the probabilistic Condensation algorithm

Navigation d'une aiguille médicale déformable

Les environnements actuels de navigation de gestes interventionnels avec aiguille font l'hypothèse de l'indéformabilité de celle-ci. Hypothèse non vérifiée cliniquement avec comme conséquence immédiate une perte de précision du geste réalisé et à plus long terme de potentielles conséquences morbides. En pratique, cette aiguille peut être amenée à se déformer du fait des interactions avec les tissus. Il est donc nécessaire d'incorporer dans les systèmes de navigation des données sur la déformée de l'aiguille à l'aide, par exemple, de jauges de déformation. Ces dernières permettent d'accéder en temps réel à des informations locales de déformation, a partir desquelles il sera possible de reconstruire la déformée de l'aiguille. L'objectif de ce travail consiste donc à l'élaboration d'une nouvelle génération de système de navigation permettant de localiser en 3D et en temps réel, la déformée d'une aiguille instrumentée.The current environments of navigation of interventional gestures with needle make the assumption of the indeformability of this one. Unchecked hypothesis clinicaly with as immediate consequence a loss of precision of the gesture carried out and longer-term of potential morbid consequences. In practice, this needle can be brought to deform because of the interactions with tissues. It is thus necessary to incorporate in the navigation systems of the data on the bending of the needle to the assistance, for example, of strain gauges. These last ones allow to reach in real time local information of deformation, has to leave of which it will be possible to rebuild the deformation of the needle. The objective of this work thus consists with the development of a new generation of navigation system allowing to localize in 3D and real time, the deformation of an instrumented needle.SAVOIE-SCD - Bib.électronique (730659901) / SudocGRENOBLE1/INP-Bib.électronique (384210012) / SudocGRENOBLE2/3-Bib.électronique (384219901) / SudocSudocFranceF

Multi-View Vision System for Laparoscopy Surgery.

International audienceThis paper deals with the development of a new generation of augmented laparoscopy system. We propose to equip a traditional endoscope, or a robotic endoscope holder, with a miniature stereovision device. The system includes two miniature high resolution CMOS cameras mounted around the endoscope as a pair of glasses that provides a global view of the abdominal cavity completing the traditional view. Each camera can reach a frame rate of 30 images/second with a resolution of 1600 _ 1200 pixels. A deployment, fixation and rapid extraction system of the proposed device through the trocar was designed and validated through preclinical experiments (testbench and human cadaver). The main benefit of the proposed system in the minimally invasive surgery domain is to provide simultaneously local/global views, and with perspectives in 3D reconstruction of the organ being treated

Visual servoing of a robotic endoscope holder based on surgical instrument tracking

International audienceWe propose an image-based control for a roboticendoscope holder during laparoscopic surgery. Our aim is toprovide more comfort to the practitioner during surgery byautomatically positioning the endoscope at his request. To doso, we propose to maintain one or more instruments roughly atthe center of the laparoscopic image through different commandmodes. The originality of this method relies on the direct useof the endoscopic image and the absence of artificial markersadded to the instruments. The application is validated on a testbench with a commercial robotic endoscope holder

A new way to access the interaction forces between complex tissues and needles

International audienceThe aim of this study is to determine a generic static loading basis applied on a medical needle inserted into human tissue during a percutaneous procedure. Such a basis can be worthwhile to highlight the forces effectively encountered in a medical act and may be useful to develop models of needle deflection or medium deformation

Modélisation des cinétiques de polymérisation de résines destinées à la fabrication Hors Autoclave

The main challenges with composite parts manufacturing are related to the curing means, mainly autoclaves, the length of their cycles and their operating costs. In order to decrease this dependency, out of autoclave materials have been considered as a solution for high production rate parts such as spars, flaps, etc… However, most out-of-autoclave process do not possess the same maturity as their counterpart, especially concerning part quality 1. Three out-of-Autoclave prepreg materials were considered for this study, each one possessing different curing temperatures: A (180°C), B (125°C) and C (132°C). Those materials have also different chemical compositions, although all three have been designed for out-of-autoclave composite part manufacturing (primary and secondary structures). The interest of our study is to understand and compare polymerization mechanisms of each matrix, by defining each time a predictive model close to experimental values of the curing of those epoxy/amine systems 2

Robot-based tele-echography: clinical evaluation of the TER system in abdominal aortic exploration

OBJECTIVE: The TER system is a robot-based tele-echography system allowing remote ultrasound examination. The specialist moves a mock-up of the ultrasound probe at the master site, and the robot reproduces the movements of the real probe, which sends back ultrasound images and force feedback. This tool could be used to perform ultrasound examinations in small health care centers or from isolated sites. The objective of this study was to prove, under real conditions, the feasibility and reliability of the TER system in detecting abdominal aortic and iliac aneurysms. METHODS: Fifty-eight patients were included in 2 centers in Brest and Grenoble, France. The remote examination was compared with the reference standard, the bedside examination, for aorta and iliac artery diameter measurement, detection and description of aneurysms, detection of atheromatosis, the duration of the examination, and acceptability. RESULTS: All aneurysms (8) were detected by both techniques as intramural thrombosis and extension to the iliac arteries. The interobserver correlation coefficient was 0.982 (P < .0001) for aortic diameters. The rate of concordance between 2 operators in evaluating atheromatosis was 84% +/- 11% (95% confidence interval). CONCLUSIONS: Our study on 58 patients suggests that the TER system could be a reliable, acceptable, and effective robot-based system for performing remote abdominal aortic ultrasound examinations. Research is continuing to improve the equipment for general abdominal use

Device for positioning surgical tool in the body of patient

The present disclosure relates to a device for positioning and/or orienting, in the body of a patient, a surgical tool carried by a tool-holder, including a platform capable of being placed on the body of the patient, an orientable carrier, at least one part of which is rigidly connected to the tool-holder, means for guiding the orientable carrier rotationally relative to the platform in two directions of a plane parallel to the platform, at least 2 pneumatic actuators which engage with the orientable carrier such that a variation in pressure of at least one of the pneumatic actuators causes the orientable carrier to rotate in the first direction and/or the second direction, in which the pneumatic actuators are volumes that can deform in a predetermined direction as a function of the internal pressure

Comportement mécanique et osmotique d'une membrane semi-perméable d'acétate de cellulose utilisée dans une nouvelle endoprothèse vasculaire

Malgré des propriétés intéressantes de conversion d'énergie chimique en énergie mécanique, le processus osmotique, omniprésent dans la nature, est très peu utilisé pour des applications industrielles ou biomédicales. Dans ce travail, il est envisagé de concevoir des joints gonflables par osmose capables d'éliminer les endofuites se produisant chez certains patients possédant une endoprothèse pour anévrisme de l'aorte abdominale. Le travail présenté ici porte plus particulièrement sur la caractérisation osmo-mécanique du système osmotique eau / membrane d'acétate de cellulose / saccharose. Pour cela, un dispositif original de gonflement osmotique de membrane a été conçu et utilisé. Dans les gammes de concentration en saccharose envisagées, il apparaît que la perméabilité de la membrane dépend fortement de son état de déformation, et que cette membrane présente un comportement mécanique essentiellement élasto-plastique, qui a été identifié