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Combine anterior cruciate ligament reconstruction and unicompartmental knee arthroplasty with image-based robotic surgery: a current surgical technique
No full textInternational audienceUnicompartmental knee arthroplasty (UKA) is a widely recognized treatment for isolated compartment osteoarthritis (OA). The absence of an intact anterior cruciate ligament (ACL), however, has traditionally been considered a contraindication due to its critical role in maintaining knee stability and joint kinematics. This article aims to provide a detailed description of the surgical technique for UKA with simultaneous ACL reconstruction. It offers a practical guide for surgeons interested in adopting this approach for young, active patients with ACL-deficient and medial or lateral compartment OA, utilizing an image-based robotic platform for both preoperative and intraoperative planning. Indications and contraindications for the combined treatment are also reported. This technique, described through intraoperative images and video, represents a promising, joint-preserving alternative to total knee arthroplasty for appropriately selected patients. This step-by-step approach allows for the assessment of congruence between the bone tunnels and the prosthetic components, enabling a personalized implant positioning
k-scale: k-Anonymizing Millions of Trajectories
No full textInternational audienceTrajectory datasets collected by network operators and service providers offer detailed information about individual mobility and have wide application in business and research. However, managing such data raises privacy risks, as the unique movement patterns of individuals pose significant re-identification risks and make common countermeasures like pseudonymization ineffective. The privacy-preserving data publishing (PPDP) of trajectory datasets that maintains post-anonymization accuracy and truthfulness is an open problem -especially for large datasets with millions of records like those gathered by major actors in the telco ecosystem. We close this gap with k-scale, a framework that implements k-anonymity in massive mobile user trajectory datasets, removing uniqueness while safeguarding accuracy at the record level. Not only k-scale is the first model capable of scaling k-anonymization to a dataset of one million trajectories, but it does so while also outperforming state-of-the-art methods for trajectory data publishing in terms of preserved data quality, which we prove in real-world massive datasets and applications
RibPull: Implicit Occupancy Fields and Medial Axis Extraction for CT Ribcage Scans
No full textInternational audienceWe present RibPull, a methodology that utilizes implicit occupancy fields to bridge computational geometry and medical imaging. Implicit 3D representations use continuous functions that handle sparse and noisy data more effectively than discrete methods. While voxel grids are standard for medical imaging, they suffer from resolution limitations, topological information loss, and inefficient handling of sparsity. Coordinate functions preserve complex geometrical information and represent a better solution for sparse data representation, while allowing for further morphological operations. Implicit scene representations enable neural networks to encode entire 3D scenes within their weights. The result is a continuous function that can implicitly compesate for sparse signals and infer further information about the 3D scene by passing any combination of 3D coordinates as input to the model. In this work, we use neural occupancy fields that predict whether a 3D point lies inside or outside an object to represent CT-scanned ribcages. We also apply a Laplacian-based contraction to extract the medial axis of the ribcage, thus demonstrating a geometrical operation that benefits greatly from continuous coordinate-based 3D scene representations versus voxel-based representations. We evaluate our methodology on 20 medical scans from the RibSeg dataset, which is itself an extension of the RibFrac dataset. We will release our code upon publication.</div
Instabilités mécaniques et claquage pour les tiges hélicoidales en présence de perversion
No full textInternational audienceEquilibrium configurations of helical elastic rods during quasi-static unwinding are studied experimentally and theoretically. At a critical degree of unwinding, the helical conformation destabilizes into a mixed phase consisting of two helices with opposite chiralities connected by a perversion. As unwinding progresses, the perversion migrates along the rod, eventually disappearing, leading to a pure helical conformation with opposite chirality from the initial state. Measurements of axial torque and force as functions of extension and winding reveal remarkable phenomena: (i) As the perversion migrates, the torque remains nearly constant. (ii) The transition from a pure helix to a configuration with perversion is accompanied by snapping events, seen as singularities in torque and force. (iii) At a critical force, the perversion destabilizes and transitions to a self-touching conformation. The phase diagram and overall mechanical behavior are reproduced using a biphasic model. A shooting technique, numerical path-following methods and finite element simulations are employed to assess the instability of the perversion and the associated snapping toward self-contact. The singularity at the creation of the perversion is reproduced by incorporating clamping effects within path-following methods. An analogy with first-order phase transitions is discussed. The nearly constant torque in the mixed phase is reminiscent of a Maxwell plateau, while the creation of a perversion with snapping corresponds to a nucleation event. Finally, to apply our analysis to plant tendrils, we study a specific line in the phase diagram of the mixed state corresponding to zero net turns. The associated transition is continuous and supercritical.Les configurations d'équilibre des tiges élastiques hélicoïdales lors de leur déroulement quasi-statique sont étudiées expérimentalement et théoriquement. À un degré critique de déroulement, la conformation hélicoïdale se déstabilise pour former une phase mixte constituée de deux hélices de chiralités opposées reliées par une perversion. À mesure que le déroulement se poursuit, la perversion migre le long de la tige, pour finalement disparaître, aboutissant à une conformation hélicoïdale pure de chiralité opposée de l'état initial.Les mesures du couple axial et de la force en fonction de l'extension et du déroulement révèlent des phénomènes remarquables :(i) Pendant la migration de l'inversion, le couple reste presque constant.(ii) La transition d'une hélice pure à une configuration avec inversion s'accompagne de phénomènes de rupture brusque, observés comme des singularités dans les mesures de couple et de force.(iii) À une force critique, la perversion se déstabilise pour adopter une conformation avec auto-contact.Le diagramme de phase et le comportement mécanique global sont reproduits à l'aide d'un modèle biphasique. Une technique de tir ("shooting"), des méthodes numériques de suivi de chemin et des simulations par éléments finis sont utilisées pour analyser l'instabilité de la perversion et les phénomènes claquage associés menant à l'auto-contact. La singularité à la création de la perversion est reproduite en incluant les effets de fixation dans les méthodes de suivi de chemin.Une analogie avec les transitions de phase du premier ordre est discutée. Le couple presque constant dans la phase mixte rappelle un plateau de Maxwell, tandis que la création d'une perversion accompagnée d'un claquage correspond à un événement de nucléation. Enfin, pour appliquer cette analyse aux vrilles de plantes, une ligne spécifique dans le diagramme de phase de l'état mixte correspondant à un nombre net de tours nul est étudiée. La transition associée est continue et supercritique
pELECTRE_Tri: probabilistic multiple-criteria decision-making method for sorting and classification
No full textA computational framework and a Python 3.11.7 implementation of ELECTRE Tri-B multiple-criteria decision-making and of Simos' method for determining the weights of criteria, along with documentation and examples
Quand le cinéma révèle les héritages industriels de la ville
No full textInternational audienceLe Juge Fayard, dit "le Shériff” (The Judge Fayard, "aka the Sheriff") is a film directed by Yves Boisset in 1977 and shot almost entirely in Saint-Étienne in 1976. This conference took place at the Saint-Étienne's Cinematheque, following the screening of the film, for an audience of researchers, students and the general public. It offers a look back at the various filming locations, with a particular focus on industrial heritage: Saint-Étienne as seen by the Juge Fayard."Le Juge Fayard, dit le Shériff" est un film réalisé par Yves Boisset en 1977 et presque intégralement tourné à Saint-Étienne en 1976. Cette conférence se tient à la Cinémathèque de Saint-Étienne, à la suite de la projection du film, devant un auditoire regroupant chercheurs, étudiants et grand public. Elle propose de retour sur les différents lieux de tournage, en s'arrêtant plus particulièrement sur les héritages industriels : Saint-Étienne vue par le Juge Fayard
La nuit de Didon dans le Roman d’Énéas (v. 1302-1346). De la lettre ovidienne à la scène romanesque
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Research Engine by Seintinelles: A participatory platform to foster science–society dialogue and inform research priorities in cancer research
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Dual anchoring strategy for single-atom Fe catalysts: Insights into 1O2-driven oxidation of organic contaminants
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