Computer-navigated surgery has become widely used in orthopedics in recent decades, thanks to its proven effectiveness in knee, hip and shoulder arthroplasty. This solution provides real-time assistance to the surgeon in the operating room, optimizing implant sizing and positioning. During the surgery, a specific module localizes the patient's anatomical structures thanks to markers located on the bone structures and the surgeon's instruments. Navigation software displays relevant clinical information to assist the surgeon. Existing solutions are mainly based on bi-ocular optical cameras that localize markers fixed to the areas of interest. The size and weight of the markers make these solutions unsuitable for extremity surgery, in particular trapeziometacarpal arthroplasty, where the size of the incision and bones is very small (of the order of a cm). In this context, the XtremLoc project will offer the first integrated solution to assist the surgeon and to accurately guide the fitting of a metacarpal prosthesis. The pathology targeted here is rhizarthrosis, that is osteoarthritis affecting the trapeziometacarpal joint at the base of the thumb. It is the most common form of osteoarthritis in the hand and has increased significantly in recent years, due to the more regular use of keyboards and smartphones. The main objective of the XtremLoc project is to develop a complete navigation system to repair these small joints. This device will guide the surgeon during the implantation of a trapeziometacarpal prosthesis and contribute to optimize its positioning, enabling the patient to regain better mobility and limit post-operative complications. The solution proposed in this project is based on three innovative aspects. The first involves the design of non-invasive three-dimensional optical localization system, having a micrometric accurate and compatible with the operating room environment. It incorporates mini optical retroreflectors (volume in the order of mm3) attached to bones and surgical instruments, to localize them using high-speed (kHz) laser beam scanning technology. This scanning is performed by MEMS mirrors that can rotate around two orthogonal axes. By exploiting the reflections of the laser beams on these retroreflectors, it is possible to localize them and the structures that carry them in real time (i.e. the patient's anatomical features and the surgeon's probing instruments), in terms of both position and orientation. The second component is a software suite orchestrating planning and guidance. It is based on automatic segmentation and modelling of bone structures from scanner images, enabling detection of patient-specific anatomical features and calculation of optimal implant positioning. A precise registration method between intraoperative information from optical sensors and planning data enables intraoperative guidance of the surgeon. The third part of the project involves the integration of a navigated surgery prototype combining the above hardware and software bricks. The physical implementation of the localization module will be brought into line with the rules governing housing watertightness, instrument sterilization and ocular safety, so that it can be integrated into the surgical workflow. Navigation tests will be carried out on the surgical platform PLaTIMed, enabling a complete surgery to be performed on anatomical specimens, and the final demonstrator to be validated in a realistic environment.

The aim of the OPTIMUM project is to study both experimentally and numerically metal joints produced by linear friction welding (LFW). An original and comprehensive approach which links the welding process parameters, their effects on the microstructure evolution and the consequences on the final use properties of the welded components, will be developed. The focus will be on joining new grades of titanium based or nickel based alloys and joining dissimilar materials. Multi-scale characterization techniques will be used in order to deeply analyze the effects of the process parameters on the microstructure evolution in the welded zone (i.e. the ability to interpret the mechanisms behind the different observed microstructure zones). Using finite element method, a simulation tool of the LFW process will be developed in order to study the evolutions of the thermal, the kinematic and the stress fields during the welding process. The numerical tool will describe the different steps of the LFW process and will be validated based on several experimental data (e.g. thermal fields, force-displacement…). This numerical modeling will help in interpreting the physical phenomena responsible of the microstructure evolution (e.g. the temperature level reached and the microstructure transformation, the stress fields and the refining of the microstructure). The OPTIMUM project has four main work-packages: The first work-package is devoted to welding of different pairs of titanium-based or nickel-based materials. Tests will be conducted for various process parameters (forging pressure, frequency and amplitude of oscillations) and for different geometrical configurations. The second work-package is dedicated to the physical-chemical analysis and the microstructure analysis of the weld zone supplemented by measurements of residual stresses and by hardness profiles performed by an instrumented nanoindentation technique. The third work-package is dedicated to the development of a thermo-mechanical simulation tool of the LFW process in the Forge ® software environment. The quality of the developed numerical tool will be evaluated through the comparison of experimental and numerical data such as the fields of local thermal gradients , the geometry of the welded joint (e.g. size and geometry of the burr ) and the material consumption (i.e. the reduction in the size of the slug of materials after assembly ). This tool will be subsequently used to help in the interpretation of the observed microstructure evolution (local mechanical fields, cooling rates ...). The fourth work-package of the project deals with the study of service life of welds by using 3D non-destructive experimental techniques such as X-ray tomography and laminography for the analysis of defects induced by the process (e.g. porosity). Some in situ tests with a monitoring of the damage evolution and/or crack propagation will be realized by sequential mechanical tests or in situ sub synchrotron beam.

The lasting of digital data, after the death of its users, raise nowadays several questions. What become of the identity data of web users after their death? Do they care about them when they are still alive? How do relatives deal with these data? How do major actors of the web, such as Facebook and Google, manage them? As any other digital and funeral practices, those post mortem digital practices are gendered. This project wants to shed a light on the gender dimension of these practices. How does the gender of the dead person and of those who pay tribute to him/her structure the memorial uses and the construction of post mortem identities? Such questions seem crucial when taking into account the multiplication of digital programs dedicated to memorial practices and the dramatic importance of social networks in relation to the aging of web users. For a few years, international research has explored the social issues raised by profiles of dead users, as well as the changes in the mourning practices on the web, but has paid little attention to gender issues. In France, only a few research projects have been conducted on the thematic. Even more, if theses works articulate digital practices and death or question the gender dimension of mourning, none develop a specific gender perspective on digital practices related to death. The study of death enlightens social structure and raises individual and collective issues such as the historical conceptions of the body and self-representation. This research project aims at analysing the memorial uses of the web and the construction of digital post mortem identities, by using a gender perspective and by revealing their social, economic, legal and symbolic issues. To deal with such interdisciplinary questions, this project relies on a theoretical framework made of information and communication sciences, gender studies, sociology, computer sciences and philosophy. It pays a particular attention to the development of innovative methods in visualisation. The implementation of this project consists in 6 different tasks. We propose to conduct a qualitative and quantitative analysis of memorial uses on the web in France (Task 1), an analysis of the transmedia circulation of tributes to celebrities (Task 2), and a semiotic analysis of the web memorials and of the post mortem identities they build (Task 3). These three tasks will be conducted all together during the two first years of the project. The results will be exploited during the third year in a multidisciplinary synthesis. The objective of this fourth task (Task 4) is to address the re-composition of gender and digital identities in the memorial uses of the web in France, in comparison with other geographic areas (China, USA). During the whole project (3 years), valorisation (Task 5) and coordination (Task 6) are conducted independently. The consortium assembles 2 partners. Partner 1 is the CIM research center, at Paris 3 University, specialised in Media Studies and digital practices (Team Media, Culture and Digital Practices). Members from the Labsic research center (Paris 13) are associated to the CIM. Partner 2 is COSTECH, at the Technological University of Compiègne. This interdisciplinary research centre focuses on the social stakes of technologies. The consortium shares common research themes, especially the social, political, economic, symbolic and philosophic stakes in information and communication technologies, and an experience in working together on previous research project (ARPEGE).