Distribution and variability study of the femur cortical thickness from computer tomography

In the context of patient-specific 3D bone reconstruction, enhancing the surface with cortical thickness (COT) opens a large field of applications for research and medicine. This functionality calls for database analysis for better knowledge of COT. Our study provides a new approach to reconstruct 3D internal and external cortical surfaces from computer tomography (CT) scans and analyses COT distribution and variability on a set of asymptomatic femurs. The reconstruction method relies on a short (∼5 min) initialisation phase based on 3D reconstruction from biplanar CT-based virtual X-rays and an automatic optimisation phase based on intensity-based cortical structure detection in the CT volume, the COT being the distance between internal and external cortical surfaces. Surfaces and COT show root mean square reconstruction errors below 1 and 1.3 mm. Descriptions of the COT distributions by anatomical regions are provided and principal component analysis has been applied. The first mode, 16–50% of the variance, corresponds to the variation of the mean COT around its averaged shape; the second mode, 9–28%, corresponds to a fine variation of its shape. A femur COT model can, therefore, be described as the averaged COT distribution in which the first parameter adjusts its mean value and a second parameter adjusts its shape

Nouvelles pistes pour revisiter la production de la parole et son développement : données, modèles, représentation

International audienceNew tracks to revisit speech production and speech development: data, models and representation Since several years new tracks are explored to revisit speech production, emergence and development. Data bases and modeling concerning genetics (HOX and noHOX genes), biometrical data of head, hyoid bone and cervical vertebrae (C1-C7), muscle anatomy, developmental phonetics, vocal tract modeling (geometrical and biomechanical), and swallowing physiology have been interwoven in order to provide new insights on speech production. This research integrates, along all the steps, the realization of computerized dynamic graphics and video illustrations. They will provide help for speech researchers, physicians and speech therapists.Depuis quelques années de nouvelles pistes sont explorées pour revisiter la production de la parole, son émergence et son développement. Les domaines pour lesquels il a semblé productif de croiser bases de données et modélisation concernent la génétique du développement de la tête (gênes HOX et non-HOX), du rachis cervical (C1 C7) et de l'os hyoïde, de la biométrie osseuse de la tête et du cou, de l'anatomie fonctionnelle des muscles impliqués dans production de la parole, de la phonétique du développement, de la modélisation du conduit vocal (géométrique et biomécanique) et de la physiologie de la déglutition. Pour pouvoir appréhender ces nouvelles pistes dans leur spécificité, un effort important de visualisation a été fait grâce à l'utilisation de la synthèse numérique dynamique appliquée à la croissance de l'architecture osseuse, du cerveau et du conduit vocal

Considérations ontogénétiques et phylogénétiques concernant l'origine de la parole. Prédiction de la capacité des conduits vocaux de fossiles reconstitués à produire des sons de parole

http://primatologie.revues.org/797National audienceOntogenetic and phylogenetic considerations concerning the origin of speech The end of the XXth century and the beginning of this century saw a reorganization of the researches in the field of speech and language emergence (SLE). Naturalism is the kernel of this new approach. It consists in describing the relations between biological aspects (in every sense of the word) on the one hand and speech and language, on the other hand, by an accumulation of hypotheses and evidence derived from a huge range of data collected thanks to interdisciplinary collaborations. As is the case for researches on the origin of Man, a theoretical profusion of hypotheses has arisen which sometimes leads to very hypothetical developments, based on fragile results and on too little data, and proposed in related but not fully mastered or too much simplified disciplines. This is why regular critical overviews do not seem superfluous. First, we propose a classification (push and pull theory) that provides a new reading of the various theories which have been proposed for half a century. In the present state of knowledge it is not possible to infer when our ancestors acquired the FacultyofSpeechandLanguageandSpeech: control of speech articulators, coordination between larynx and vocal tract, phonology, syntax, semantic and recursivity. Among old unsolved questions: Why is our species alone in having speech and language? Many others questions are (for the moment?) ill posed problems: we do not have sufficiently data to answer. Perhaps these questions will remain unsolved. But we think that the following question can be solved: If we suppose that our ancestors (and distant cousins) controlled their larynx and vocal tract in the same way as present-day humans, did the geometry of their vocal tract allow them to produce the universal sound structures of the languages spoken today? We analyzed 31 skulls from now to 1.5 Ma (millions years) BP (Before Present) for fossil hominids available at the Muséedel'Homme in Paris or in the literature: (1) 10-30 ka BP: modern humans: Paleolithic; (2) 90-200 ka BP: anatomically modern humans; (3) 45-90 ka BP: Neanderthals; (4) 1.5 Ma BP: Homoergaster; These skulls are all well kept and possess a jaw in the majority of cases but the vertebral column has been reconstituted. We attempt to: (1) Localize hyoid bone and then glottis position; (2) Reconstitute a vocal tract model in a plausible way using an articulatory model; (3) Quantify the acoustic capabilities of this reconstituted vocal tract. For this purpose, we combine phylogenesis and ontogenesis. We are in a position to state that our ancestors and distant cousins were equipped with a vocal tract that could produce the same variety of vowel sounds as we can today: the vowels /i a u/. The vocal tract morphology has been favorable to the emergence and production of speech since several hundreds of thousands of years. But how to know to what extent they mastered the control skills needed to produce speech? New lines of research are proposed in which orofacial abilities necessary to the emergence of speech are linked to a precursor mechanism dedicated to feeding (masticating-swallowing movements).La fin du XXe et le tout début de ce siècle révèlent une véritable réarticulation des recherches dans le domaine de l'émergence de la parole et du langage. Le naturalisme, qui est au centre de cette approche, se propose de décrire les relations entre la biologie (au sens très large du terme) d'une part, la parole et le langage, d'autre part, par une accumulation d'hypothèses, de données et de preuves formulées et établies grâce à de multiples collaborations interdisciplinaires. Comme pour les travaux sur l'origine de l'Homme (la découverte d'un nouveau fossile entraînant souvent une remise en question des théories précédentes), on assiste à un foisonnement théorique qui entraîne parfois des développements très hypothétiques, s'appuyant sur des résultats fragiles et sur trop peu de données, proposés dans des disciplines connexes mais non maîtrisées ou trop simplifiées. C'est pourquoi les bilans réguliers, les mises en perspectives critiques ne nous semblent pas superflus. Dans un premier temps nous proposerons une classification qui permet une lecture des différentes théories proposées depuis un demi-siècle (théorie push-pull). Dans l'état actuel des connaissances, il n'est pas possible d'inférer quand nos ancêtres, voire nos lointains ont acquis la faculté de langage et de parole : le contrôle des articulateurs, la coordination entre le larynx et le conduit vocal, la phonologie, la syntaxe, la sémantique et la récursivité. Parmi les questions qui se posent, il en est une qui reste sans réponse : pourquoi notre espèce est actuellement la seule à posséder langue et parole ? De nombreuses questions font partie des problèmes mal posés, comme le sont les questions du type: Quelle(s) langue(s) parlaient nos prédécesseurs ? Possédaient-ils une langue unique ? En effet, on ne dispose pas (pour le moment) de suffisamment de données pour pouvoir y répondre. Peut-être même que ces questions ne trouveront pas de solution. Actuellement, il est quand même possible de répondre à la question suivante : si nous supposons que nos ancêtres (et cousins lointains) contrôlaient leur larynx et leur conduit vocal de la même manière que les Hommes actuels, est-ce que la géométrie de leur conduit leur permettaient de produire les structures sonores qui sont pratiquement présentes dans toutes les langues du monde ? Nous présenterons ensuite nos travaux qui participent à la nouvelle réarticulation avec une approche véritablement axée sur la pluridisciplinarité. Ils s'inscrivent dans le domaine des relations entre la morphologie des organes de la production de la parole et son contrôle. Nous présentons de nouveaux résultats concernant la croissance du conduit vocal de la naissance à l'âge adulte puis des reconstructions du conduit vocal pour des fossiles qui couvrent la période de 10.000 ans à un million et demi d'années BP (Before Present). À partir du crâne, de la mandibule et des vertèbres cervicales nous essaierons de manière plausible (1) de localiser l'os hyoïde, support de la langue, et la position de la glotte, (2) de reconstituer un conduit vocal, à l'aide d'un modèle articulatoire, (3) d'induire les possibilités acoustiques de tous ces conduits. En combinant phylogenèse et ontogenèse il est possible de représenter l'anatomie du tractus en synthétisant deux remodelages qui renvoient à l'ontogenèse et à la phylogenèse. Nous montrerons que tous ces conduits ont les mêmes potentialités acoustiques, ils peuvent produire les voyelles /i a u/ qui sont pratiquement présentes dans toutes les langues du monde : un triangle à l'intérieur duquel se situent toutes les autres voyelles. Quand aux consonnes les plus fréquentes /p t k/, /b d g/ elles sont aussi à la portée de tous ces conduits vocaux à partir de gestes de fermeture dans des régions précises (lèvres, zone alvéodentale, zone vélaire). De nouvelles pistes de recherche sont proposées qui tendraient à montrer qu'il y a vraisemblablement plusieurs centaines de milliers, voire plusieurs millions d'années que le conduit vocal présente une morphologie favorable à l'émergence et à la production de la parole. Un cadre est posé dans lequel les capacités orofaciales nécessaire à la parole pourraient être reliées au mécanisme précurseur d'ingestion (mastication-déglutition)

Synergies between machine learning and reasoning - An introduction by the Kay R. Amel group

This paper proposes a tentative and original survey of meeting points between Knowledge Representation and Reasoning (KRR) and Machine Learning (ML), two areas which have been developed quite separately in the last four decades. First, some common concerns are identified and discussed such as the types of representation used, the roles of knowledge and data, the lack or the excess of information, or the need for explanations and causal understanding. Then, the survey is organised in seven sections covering most of the territory where KRR and ML meet. We start with a section dealing with prototypical approaches from the literature on learning and reasoning: Inductive Logic Programming, Statistical Relational Learning, and Neurosymbolic AI, where ideas from rule-based reasoning are combined with ML. Then we focus on the use of various forms of background knowledge in learning, ranging from additional regularisation terms in loss functions, to the problem of aligning symbolic and vector space representations, or the use of knowledge graphs for learning. Then, the next section describes how KRR notions may benefit to learning tasks. For instance, constraints can be used as in declarative data mining for influencing the learned patterns; or semantic features are exploited in low-shot learning to compensate for the lack of data; or yet we can take advantage of analogies for learning purposes. Conversely, another section investigates how ML methods may serve KRR goals. For instance, one may learn special kinds of rules such as default rules, fuzzy rules or threshold rules, or special types of information such as constraints, or preferences. The section also covers formal concept analysis and rough sets-based methods. Yet another section reviews various interactions between Automated Reasoning and ML, such as the use of ML methods in SAT solving to make reasoning faster. Then a section deals with works related to model accountability, including explainability and interpretability, fairness and robustness. Finally, a section covers works on handling imperfect or incomplete data, including the problem of learning from uncertain or coarse data, the use of belief functions for regression, a revision-based view of the EM algorithm, the use of possibility theory in statistics, or the learning of imprecise models. This paper thus aims at a better mutual understanding of research in KRR and ML, and how they can cooperate. The paper is completed by an abundant bibliography

Modélisation tridimensionnelle des organes de la parole à partir d'images IRM pour la production de nasales - Caractérisation articulatori-acoustique des mouvements du voile du palais.

The goal of this work was the articulatory-acoustic characterization of nasality: the nature of velopharyngeal port movement and associated acoustic characteristics. The building of a 3D linear single-subject articulatory model of the nasal tract from MRI and CT images revealed two degrees of freedom for the movements of the velum and nasopharyngeal wall. The dominant parameter corresponds to a joint vertical oblique movement of the velum and a horizontal movement of the pharyngeal wall, expressing the sphincter effect of the velopharyngeal port. The second parameter corresponds to a smaller movement of the velum, significantly modifying the nasal coupling area. The space covered by the model's movements corresponds precisely to that described by a velum point measured by electromagnetic articulography. Realistic area functions of the nasal tract derived from the model allowed us to determine acoustic transfer functions for seven vowels and the acoustic influence of velar movements.Ce travail a pour objectif la caractérisation articulatori-acoustique de la nasalité: nature des mouvements du port vélopharyngé, caractéristiques acoustiques liées. La construction d'un modèle articulatoire linéaire 3D monosujet du conduit nasal à partir d'images IRM et CT a fait émerger deux degrés de liberté parmi les mouvements du voile du palais et de la paroi nasopharyngée. Le premier, prédominant, correspond à un mouvement conjoint vertical oblique du voile et horizontal de la paroi pharyngée, traduisant l'effet de sphincter du port vélopharyngé, et le second à un petit mouvement horizontal du voile seul, modifiant sensiblement l'aire de couplage nasal. L'espace des mouvements du modèle décrit exactement celui d'un point du voile obtenu par articulographie électromagnétique. Les fonctions d'aire réalistes du conduit nasal déduites du modèle ont permis de déterminer les fonctions de transfert acoustiques de sept voyelles et l'influence acoustique des mouvements du voile

A three-dimensional articulatory model of the velum and nasopharyngeal wall based on MRI and CT data

International audienceAn original three-dimensional 3D linear articulatory model of the velum and nasopharyngeal wall has been developed from magnetic resonance imaging MRI and computed tomography images of a French subject sustaining a set of 46 articulations, covering his articulatory repertoire. The velum and nasopharyngeal wall are represented by generic surface triangular meshes fitted to the 3D contours extracted from MRI for each articulation. Two degrees of freedom were uncovered by principal component analysis: first, VL accounts for 83% of the velum variance, corresponding to an oblique vertical movement seemingly related to the levator veli palatini muscle; second, VS explains another 6% of the velum variance, controlling a mostly horizontal movement possibly related to the sphincter action of the superior pharyngeal constrictor. The nasopharyngeal wall is also controlled by VL for 47% of its variance. Electromagnetic articulographic data recorded on the velum fitted these parameters exactly, and may serve to recover dynamic velum 3D shapes. The main oral and nasopharyngeal area functions controlled by the articulatory model, complemented by the area functions derived from the complex geometry of each nasal passage extracted from coronal MRIs, were fed to an acoustic model and gave promising results about the influence of velum movements on the spectral characteristics of nasals

Towards a 3D articulatory model of velum based on MRI and CT images

This paper describes the processing of MRI and CT images needed for developing a 3D linear articulatory model of velum. The 3D surface that defines each organ constitutive of the vocal and nasal tracts is extracted from MRI and CT images recorded on a subject uttering a corpus of artificially sustained French vowels and consonants. First, the 2D contours of the organs have been manually extracted from the corresponding images, expanded into 3D contours, and aligned in a common 3D coordinate system. Then, for each organ, a generic mesh has been chosen and fitted by elastic deformation to each of the 46 3D shapes of the corpus. This has finally resulted in a set of organ surfaces sampled with the same number of 3D vertices for each articulation, which is appropriate for Principal Component Analysis or linear decomposition. The analysis of these data has uncovered two main uncorrelated articulatory degrees of freedom for the velum's movement. The associated parameters are used to control the model. We have in particular investigated the question of a possible correlation between jaw / tongue and velum's movement and have not find more correlation than the one found in the corpus

Articulatory modelling of nasals: data and models

International audienceThe problem of nasality is complex and has given rise to a large number of studies, from both perception and production points of view. The nasality feature is related to the velum position: lowering the velum, and thus opening the velopharyngeal port, is a simple gesture that induces strong and complex changes in the vocal tract acoustical behaviour. The realisation of nasality involves (1) an articulatory level that deals with the shape of the articulators and their degrees of freedom, and (2) a control level that deals with the coordination of these articulators. The present contribution describes our attempts to characterise at both levels the nasality as realised by one specific subject. The first part is devoted to the development of a 3D articulatory model of the velum that complements the jaw, tongue and lips models already built from MRI data collected on the same subject (Badin et al., 2002). The corpus consisted of a set of artificially sustained phonemes designed as to cover the maximal range of velum positions: the four French nasal vowels and their oral counterparts, and the consonants [p t m n] in three symmetrical contexts [a i u]. Following a method already proven for orofacial articulatory modelling (Badin et al., 2002), the 3D coordinates defining the velum geometry extracted from the MRI data were submitted to decomposition in linear components. Two parameters were found to control the velum, roughly corresponding to vertical and horizontal movements of the uvula, and explaining 74 % of the data variance, with an RMS reconstruction error of 0.13 cm. In addition, a detailed description of the 3D geometry of the nasal and paranasal cavities of the subject was obtained from EBCT scans, and associated with the velum and tongue models to reconstruct area functions. The use of 3D is particularly important, as it appears that the subject's uvula is often in contact with both the back of the tongue and the pharyngeal wall, creating an occlusion in the midsagittal plane, though lateral canals remain open. The influence of tongue upon velum was also studied in detail. The whole model provides finally a link between the oropharyngeal port area and the velum control parameters. The second aspect of the work was the study of the effects of spatial and contextual coarticulation on the velum position in vowels and consonants, and on the associated acoustic outputs. We present an articulatory analysis of velar movements obtained by ElectroMagnetic Articulography for consonants and vowels recorded for the MRI subject uttering the same corpus of VCV sequences. These findings increase our knowledge of the articulatory control of nasality, and open the way to the articulatory synthesis of nasal vowels and consonants. Badin, P., Bailly, G., et al. (2002). Three-dimensional articulatory modeling of tongue, lips and face, based on MRI and video images. J. Phonetics, 30(3), 533-553