Aujourd’hui, l’imagerie médicale est une composante majeure du développement de la médecine : l’analyse d’image et son déploiement sont un axe de recherche central à l’INRIA (Institut national de la recherche en Informatique et automatique), pionnier du domaine en France et à l’international. Cependant, réalisée sur le long terme, l’importance de cette recherche fondamentale est difficile à évaluer. En outre, fondée sur le principe de la coopération, le rôle de l’INRIA peut être sous-estimé au profit de ses partenaires. L’objectif historique de cette thèse est de montrer l’importance du rôle de l’INRIA en analyse d’imagerie médicale via l’exemple de son équipe-projet EPIDAURE/ASCLEPIOS, première en ce domaine. Cette investigation est adossée à trois paradigmes méthodologiques : une recherche bibliographique, une synthèse à partir des archives de l’INRIA-Rocquencourt (Île-de-France) et de dix entretiens semi-dirigés, réalisés par nos soins, auprès de chercheurs de l’INRIA directement impliqués dans l’analyse d’imagerie médicale. Les résultats montrent que dès les années 90 du XXe siècle, l’équipe-projet EPIDAURE/ASCLEPIOS a été fondatrice de ce domaine dans le monde. En outre, elle est à l’origine d’une nouvelle révolution du numérique, via la conception du « Patient numérique personnalisé » (PNP), proposée par son directeur Nicholas AYACHE dont le rôle central sur cet axe se traduit par l’excellence des résultats publiés et par la richesse et le dynamisme des collaborations établies, dans les domaines : académique, médical et industriel. Le soutien de la direction de l’INRIA à l’équipe-projet EPIDAURE/ASCLEPIOS est un atout de son succès, sur la scène internationale. / Today, medical imaging is a major component of the medicine development: image analysis and its deployment are a central research area at INRIA (French Institute for Research in Computer Science and Automation), pioneer in this field, in France and abroad. However, it is difficult to evaluate this kind of fundamental research because of its long-term realization. Moreover, given that the research at INRIA is based on cooperation, its role may be underestimated for the benefit of its partners. The historical objective of this thesis is to show the importance of INRIA’s role in medical imaging analysis through the example of EPIDAURE / ASCLEPIOS, leading team in this field. This investigation is based on three methodological paradigms: a bibliographic search, a synthesis from the archives of INRIA-Rocquencourt (Ile-de-France) and ten semi-directed interviews, conducted by us, with INRIA researchers directly involved in Medical imaging the analysis. The results show that since the 90s of the 20th century, the EPIDAURE / ASCLEPIOS project-team has been the founder of this field in the world. Moreover, this team is the origin of a new digital revolution, through the design of the "Personalized Digital Patient", proposed by its director Nicholas AYACHE, whose central role in this line of research is reflected in the excellence of published results, the wealth and dynamism of established collaborations in the academic, medical and industrial fields. The support of INRIA’s management to the EPIDAURE / ASCLEPIOS project-team is an asset of its success on the international scene.

<p>This thesis consists of the structure-preserving numerical methods for PNP-NS equation and dynamic liquid crystal systems in Oseen-Frank energy. </p> <p>In Chapter 1, we give a brief introduction of the Poisson-Nernst-Planck-Navier-Stokes (PNP-NS) system, and the dynamical liquid system in Oseen-Frank energy in one-constant approximation case and a special non-one-constant case. Each of those systems has a special structure and properties we want to keep at the discrete level when designing numerical methods.</p> <p>In Chapter 2, we introduce a first-order numerical scheme for the PNP-NS system that is decoupled, positivity preserving, mass conserving, and unconditionally energy stable. The numerical scheme is designed in the context of Wasserstein gradient flow based on the form ∇ · (c∇ ln c). The mobility terms are treated explicitly, and the chemical potential terms are treated implicitly so that the solution of the numerical scheme is the minimizer of a convex functional, which is the key to the unique solvability and positivity preserving of the numer-<br> ical scheme. Proper boundary conditions for chemical potentials are chosen to guarantee the mass-conservation property. The convection term in Poisson-Nernst-Planck(PNP) equation part is treated explicitly with an O(∆t) term introduced so that the numerical scheme is decoupled and unconditionally energy stable. Pressure correction methods are used for the Navier-Stokes(NS) equation part. And we proved the optimal convergence rate with an irregular high-order asymptotic expansion technique.</p> <p>In Chapter 3, we propose a first-order implicit numerical method for a dynamic liquid crystal system in a one-constant-approximation case(which is also known as heat flow of harmonic maps to S2). The solution is the minimizer of a convex functional under the unit length constraint, and from this point, the weak convergence of the numerical scheme could be proved. The numerical scheme is solved in an iterative procedure. This procedure could be proved to be energy decreasing and this implies the convergence of the algorithm.</p> <p>In Chapter 4, we study the dynamic liquid crystal system in a more generalized Oseen- Frank energy compared to Chapter 3. We are assuming K2 = K3 = −K4, the domain Ω is a rectangular region in R3, and d satisfies the periodic boundary condition on ∂Ω. And we propose a class of numerical schemes for this system that preserve the unit length constraint. The convergence of the numerical scheme has been proved under necessary assumptions. And numerical experiments are presented to validate the accuracy and demonstrate the performance of the proposed numerical scheme.</p>

The automotive safety company Veoneer are producers of high end driver visual assistance systems, but the knowledge about the absolute accuracy of their dynamic calibration algorithms that estimate the vehicle’s orientation is limited. In this thesis, a novel measurement system is proposed to be used in gathering reference data of a vehicle’s orientation as it is in motion, more specifically the pitch and roll angle of the vehicle. Focus has been to estimate how the uncertainty of the measurement system is affected by errors introduced during its construction, and to evaluate its potential in being a viable tool in gathering reference data for algorithm performance evaluation. The system consisted of three laser distance sensors mounted on the body of the vehicle, and a range of data acquisition sequences with different perturbations were performed by driving along a stretch of road in Linköping with weights loaded in the vehicle. The reference data were compared to camera system data where the bias of the calculated angles were estimated, along with the dynamic behaviour of the camera system algorithms. The experimental results showed that the accuracy of the system exceeded 0.1 degrees for both pitch and roll, but no conclusions about the bias of the algorithms could be drawn as there were systematic errors present in the measurements. / Bilsäkerhetsföretaget Veoneer är utvecklare av avancerade kamerasystem inom förarassistans, men kunskapen om den absoluta noggrannheten i deras dynamiska kalibreringsalgoritmer som skattar fordonets orientering är begränsad. I denna avhandling utvecklas och testas ett nytt mätsystem för att samla in referensdata av ett fordons orientering när det är i rörelse, mer specifikt dess pitchvinkel och rollvinkel. Fokus har legat på att skatta hur osäkerheten i mätsystemet påverkas av fel som introducerats vid dess konstruktion, samt att utreda dess potential när det kommer till att vara ett gångbart alternativ för att samla in referensdata för evaluering av prestandan hos algoritmerna. Systemet bestod av tre laseravståndssensorer monterade på fordonets kaross. En rad mätförsök utfördes med olika störningar introducerade genom att köra längs en vägsträcka i Linköping med vikter lastade i fordonet. Det insamlade referensdatat jämfördes med data från kamerasystemet där bias hos de framräknade vinklarna skattades, samt att de dynamiska egenskaperna kamerasystemets algoritmer utvärderades. Resultaten från mätförsöken visade på att noggrannheten i mätsystemet översteg 0.1 grader för både pitchvinklarna och rollvinklarna, men några slutsatser kring eventuell bias hos algoritmerna kunde ej dras då systematiska fel uppstått i mätresultaten.