A language and an Integrated Environment for Program Transformations

We present the TrfL language, a rule-based language designed for program transformations. For the end-user, TrfL is intended to support both direct manipulation in an interactive setting and automated execution in a stand-alon- e context. For the designer, the TrfL language features a high-level expressiv- e power based on powerful patterns, pre-conditions and post-actions, access to contextual information such as symbol tables or dataflow graphs, and functional composition of transformations. For the designer, we also provide an interactive environment for program transformations based on Centaur. This integrated environment makes it possible to build transformation rules by selection of syntax patterns of the object language and to automatically generate the TrfL source code. Static typechecking of TrfL rules is provided, to ensure correct construction of patterns, appropriate use of variables, and visibility rules in a program. Among numerous application domains (legacy code problems, static optimizations, parallelizations), we propose in this article a complete example based on partial evaluation techniques on a toy imperative language. Our final goal, with a formal description of the transformations, besides its interest per se, is to be able to provide tools for proving the correctness of the transformations, as well as other important properties (such as confluence, termination, etc)

Airborne ultrasound measurement of posturo-respiratory interaction

In healthy subjects, spinal alignment varies with the variations of lung volume and the natural breathing perturbs physiologically the balance. The reciprocal action between respiratory postural perturbation and partial counteraction of cyclic movements of the spine, pelvis and lower limbs represents the posturo-respiratory interaction (PRI). The PRI is centrally controlled. In the Obstructive Sleep Apnoea Syndrome (OSAS) specifics postural dysfunctions related to an abnormal PRI is observed. Numerous tools exist to measure the PRI. We propose an alternative approach which is contactless and non-invasive using airborne ultrasound devices. This approach offers the advantages to simultaneously assess breathing and postural variations and to be easily implemented in clinical settings. We first evaluate the performance of our device to assess the breathing pattern compared to that of a spirometer. We secondly use our approach to qualify the PRI by measuring the postural variation at the level of the T7 vertebra. We introduce a new parameter named pseudo-emergence similar to the classical emergence parameter. This parameter gives a value of 8.33%. This value is close to the median emergence that was compute from predecessor. We have demonstrated that the proposed method allows a reliable measurement of breathing. We also offer a contactless approach of a respiratory pseudo-emergence parameter to evaluate the PRI. The obtained parameters seem promising and consistent with the literature, but need to be confirm.Programme SOUFFLE de l'Institut Universitaire d'Ingénierie en Santé (IUIS

Biplanar Low-Dose Radiograph Is Suitable for Cephalometric Analysis in Patients Requiring 3D Evaluation of the Whole Skeleton

Background: The biplanar 2D/3D X-ray technology (BPXR) is a 2D/3D imaging system allowing simultaneous stereo-corresponding posteroanterior (PA) and lateral 2D views of the whole body. The aim of our study was to assess the feasibility of cephalometric analysis based on the BPXR lateral skull view to accurately characterize facial morphology. Method: A total of 17 landmarks and 11 angles were placed and/or calculated on lateral BPXR and lateral cephalograms of 13 patients by three investigators. Five methods of angle identification were performed: the direct construction of straight lines on lateral cephalograms (LC-A) and on BPXR (BPXR-A), as well as the calculation of angles based on landmark identification on lateral cephalograms (LA-L) and on BPXR with the PA image (BPXR-LPA) or without (BPXR-L). Intra- and interoperator reliability of landmark identification and angle measurement of each method were calculated. To determine the most reliable method among the BPXR-based methods, their concordance with the reference method, LC-A, was evaluated. Results: Both imaging techniques had excellent intra- and interoperator reliability for landmark identification. On lateral BPXR, BPXR-A presented the best concordance with the reference method and a good intra- and interoperator reliability. Conclusion: BPXR provides a lateral view of the skull suitable for cephalometric analysis with good reliability

Breathing through a spirometer perturbs balance

Natural breathing is known to induce at each inspiration/expiration, minimal perturbations of body balance that are compensated by movement of trunk and lower limb (Hodges et al. 2002). This phenomenon called posturo ventilatory synchronization may be impaired (Manor et al. 2012). Its evaluation requires simultaneous assessments of ventilation profile and postural control, using the less disruptive methods. Spirometry is the reference method to assess the ventilatory parameters. It requires however to connect the subject to the spirometer, using a mouthpiece, that is known to modify significantly the respiratory frequency (Gilbert et al. 1972) and may influence the postural control. The Optoelectronic Plethysmography (OEP) was validated as an alternative non-disruptive method to assess ventilation as it allows subjects to breathe naturally. Evidently, non-contact measure of ventilation by camera is supposed to induce no perturbation of postural control, and may be more appropriate than spirometer to assess the posturo ventilator synchronization. The objective of this study was to evaluate the postural perturbations due to the use of the spirometer, by comparing it to the OEP method, on postural control

Cervical Spine Hyperextension and Altered Posturo-Respiratory Coupling in Patients With Obstructive Sleep Apnea Syndrome.

Obstructive sleep apnea syndrome (OSAS) is associated with postural dysfunction characterized by abnormal spinal curvature and disturbance of balance and walking, whose pathophysiology is poorly understood. We hypothesized that it may be the result of a pathological interaction between postural and ventilatory functions. Twelve patients with OSAS (4 women, age 53 years [51-63] (median [quartiles]), apnea hypopnea index 31/h [24-41]) were compared with 12 healthy matched controls. Low dose biplanar X-rays (EOS® system) were acquired and personalized three-dimensional models of the spine and pelvis were reconstructed. We also estimated posturo-respiratory coupling by measurement of respiratory emergence, obtaining synchronized center of pressure data from a stabilometric platform and ventilation data recorded by an optico-electronic system of movement analysis. Compared with controls, OSAS patients, had cervical hyperextension with anterior projection of the head (angle OD-C7 12° [8; 14] vs. 5° [4; 8]; p = 0.002), and thoracic hyperkyphosis (angle T1-T12 65° [51; 71] vs. 49° [42; 59]; p = 0.039). Along the mediolateral axis: (1) center of pressure displacement was greater in OSAS patients, whose balance was poorer (19.2 mm [14.2; 31.5] vs. 8.5 [1.4; 17.8]; p = 0.008); (2) respiratory emergence was greater in OSAS patients, who showed increased postural disturbance of respiratory origin (19.2% [9.9; 24.0] vs. 8.1% [6.4; 10.4]; p = 0.028). These results are evidence for the centrally-mediated and primarily respiratory origin of the postural dysfunction in OSAS. It is characterized by an hyperextension of the cervical spine with a compensatory hyperkyphosis, and an alteration in posturo-respiratory coupling, apparently secondary to upper airway instability.This work was supported in part by the Legs Poix (LEG 1604) of the Chancellerie des Universités de Paris. LC was supported by a Ph.D. fellowship from ENS Cachan. VA was the recipient of a grant poste d’accueil APHP/Arts et Métiers délégation à la Recherche Clinique et à l’Innovation (DRCI), Assistance Publique Hôpitaux de Paris (APHP). SR-N was the recipient of a grant of ResMed (France). The authors acknowledge the support of the Paristech BiomeCAM chair on subject specific modeling, with the support of Société Générale and COVEA

Decreased respiratory-related postural perturbations at the cervical level under cognitive load

PURPOSE: In healthy humans, postural and respiratory dynamics are intimately linked and a breathing-related postural perturbation is evident in joint kinematics. A cognitive dual-task paradigm that is known to induce both postural and ventilatory disturbances can be used to modulate this multijoint posturo-ventilatory (PV) interaction, particularly in the cervical spine, which supports the head. The objective of this study was to assess this modulation. METHODS: With the use of optoelectronic sensors, the breathing profile, articular joint motions of the cervical spine, hip, knees and ankles, and centre of pressure (CoP) displacement were measured in 20 healthy subjects (37 years old [29; 49], 10 females) during natural breathing (NB), a cognitive dual task (COG), and eyes-closed and increased-tidal-volume conditions. The PV interaction in the CoP and joint motions were evaluated by calculating the respiratory emergence (REm). RESULTS: Only the COG condition induced a decrease in the cervical REm (NB: 17.2% [7.8; 37.2]; COG: 4.2% [1.8; 10.0] p = 0.0020) concurrent with no changes in the cervical motion. The CoP REm (NB: 6.2% [3.8; 10.3]; COG: 12.9% [5.8; 20.7] p = 0.0696) and breathing frequency (NB: 16.6 min-1 [13.3; 18.7]; COG: 18.6 min-1 [16.3; 19.4] p = 0.0731) tended to increase, while the CoP (p = 0.0072) and lower joint motion displacements (p < 0.05) increased. CONCLUSION: This study shows stable cervical spine motion during a cognitive dual task, as well as increased postural perturbations globally and in other joints. The concurrent reduction in the PV interaction at the cervical spine suggests that this "stabilization strategy" is centrally controlled and is achieved by a reduction in the breathing-related postural perturbations at this level. Whether this strategy is a goal for maintaining balance remains to be studied.This work was funded by the Chancellerie des Universités de Paris (Grant number: Legs Poix (LEG 1604)); ENS Cachan (Grant number: Ph.D. fellowship); Assistance Publique - Hôpitaux de Paris (Grant number: Grant “poste d’accueil APHP/Arts et Métiers” délé- gation à la Recherche Clinique et à l’Innovation (DRCI)); Paristech (Grant number: BiomeCAM chair)

Mémoire pour l'obtention de l'Habilitation à Diriger les Recherches

This document supports the application for the « Habilitation à Diriger les Recherches ». The candidate, MD-PhD belonging to Sorbonne Université, is a Pulmonologist and Sleep specialist in the Pitié-Salpêtrière University Hospital and a senior Researcher in the Experimental and Clinical Neurophysiology Laboratory, UMR_S 1158 Sorbonne Université Inserm.The first section summarizes the personal and professional experience of the candidate. The second section lists her scientific publications. The third section describes her laboratory research supervisory. The fourth section details the candidate’s research experience, focusing on both experimental and clinical research aspects of her research activities. The experimental research concerned firstly the alteration of central integration of respiratory muscles, including diaphragm and upper airways respiratory muscles, in amyotrophic lateral sclerosis (ALS) and in obstructive sleep apnea syndrome (OSAS). These experiments were based on diaphragm electromyography, phrenic nerve central conduction time assessed by cortical and cervical magnetic stimulations and pre-inspiratory electroencephalographic potentials. For two years, the experimental research concerns the central posturo-respiratory synchronisation in healthy and patients suffering from chronic respiratory diseases, including obstructive sleep apnea syndrome. The last section describes the candidate’s experimental and clinical research projects. The experimental research will extend the knowledges on posturo-respiratory synchronisation, using high quality tools, available in the “Institut de Biomécanique Humaine Georges Charpak” Arts et Métiers ParisTech : EOS 2D/3D Xrays, motion capture coupled with stabilometry. Clinical research is in line with previous and current works and clinical activities of the candidate. It focuses on alternative therapy to CPAP in OSAS and assessment of respiratory-related postural dysfunction in chronic respiratory diseases in routine practice.La première partie de ce mémoire décrit le parcours personnel et professionnel de la candidate à l’habilitation à diriger des recherches, pneumologue dans le service des Pathologies du Sommeil au sein du Groupe Hospitalo-Universitaire Pitié-Salpêtrière-Charles Foix. La seconde partie de ce mémoire détaille ses publications et communications scientifiques. La troisième partie présente l’activité d’encadrement des jeunes chercheurs. La quatrième partie détaille les recherches conduites par la candidate à la date de soutenance du mémoire. Ses travaux de recherche fondamentale s’inscrivent dans la thématique « neurophysiologie respiratoire » de l’unité à laquelle elle est affiliée (UMRS_1158). Ils s’articulent autour de la notion d’intégration corticale de la respiration et des muscles respiratoires au sens large, incluant le diaphragme et les muscles des voies aériennes supérieures, à l’éveil et au cours du sommeil, chez le sujet sain et le patient atteint de maladie respiratoire chronique. La sclérose latérale amyotrophique (SLA) et le syndrome d’apnées obstructives du sommeil (SAOS) ont été utilisés comme modèles pathologiques. L’atteinte diaphragmatique secondaire à l’atteinte des motoneurones phréniques au cours de la SLA, a été caractérisée par l’étude des temps de conduction cortico-phréniques et son retentissement au cours du sommeil a été décrit par polysomnogrpahie. La mise en évidence de potentiels pre-inspiratoires électroencéphalographiques dans le SAOS a permis d’identifier une adaptation corticale respiratoire pathologique à l’éveil. L’intégration centrale de l’interaction entre les fonctions posturale et respiratoire est une thématique nouvelle, menée en collaboration avec l’Institut de Biomécanique Humaine Georges Charpak (Arts et Métiers ParisTech). Cette thématique développée dans la cinquième partie, constitue actuellement l’axe principal du projet de recherche de la candidate. Elle s’appuie sur l’existence d’un couplage neuromécanique entre la posture et la respiration. L’existence de dysfonctions posturales spécifiques chez les patients présentant une pathologie respiratoire chronique pourrait résulter d’une altération de ce couplage. Cette recherche s’appuie sur des outils haut de gamme d’étude de l’alignement postural par système EOS permettant la reconstruction d’un modèle spécifique en 3D du squelette à partir de clichés biplanaires du corps entier. La synchronisation centrale posturo-ventilatoire est approchée par enregistrement non disruptif de la ventilation (naturelle, dirigée, double tâche) par caméras optoélectroniques (motion capture), couplé à une stabilométrie, suivi de traitement des données (analyse stabilométrique, stochastique, calcul de l’index de synchronisation, analyses de non-linéarité des signaux). L’activité de recherche clinique est facilitée par l’activité clinique de la candidate dans le service des Pathologies du Sommeil. Elle porte sur les traitements alternatifs à la pression positive continue nocturne dans le SAOS (orthèses, stimulation du XII, neuromodulation), ainsi que la caractérisation des troubles posturaux en pathologie respiratoire chronique en pratique clinique

Upper airways stability and central integration

Le syndrome des apnées obstructives du sommeil (SAOS) est caractérisé par des épisodes répétitifs de collapsus des voies aériennes supérieures (VAS) durant le sommeil. Au cours du SAOS les propriétés mécaniques des voies aériennes supérieures sont altérées, dans le sens d'une réduction de leur capacité à laisser passer l'air, ce qui peut être assimilé à une "charge" inspiratoire. Les apnées obstructives ne se produisent jamais à l'éveil, suggérant qu'il existe, des mécanismes protecteurs d'origine corticale, de type " compensation de charge ", liés à l'éveil. Ce travail permis de caractériser ces mécanismes chez le sujet sain et le patient SAOS. Une première étude a décrit la relation pression/débit des VAS à l'éveil afin d'approcher le phénomène de compensation de charge, avant et après un traitement modulant le contrôle neurovégétatif des VAS par la compression du ganglion ptérygopalatin. La deuxième étude a mis en évidence à l'éveil chez les patients SAOS, une activité corticale motrice liée à la respiration (présence de potentiels électroencephalographiques - PPI), dont l'origine semble liée à la dysfonction des VAS, et qui est susceptible d'expliquer l'augmentation du niveau de contrôle respiratoire central connu dans le SAOS. La troisième étude a mis en évidence un phénomène de filtrage des sensations respiratoires à l'éveil chez des patients SAOS, avec restauration des ces sensations sous orthèse d'avancée mandibulaire, permettant de relier l'amélioration des propriétés mécaniques des VAS à l'intégration centrale des sensations respiratoires. Enfin la relation pression/débit a fait l'objet de deux modélisations.The obstructive sleep apnoea syndrome (OSAS) involves recurrent sleep-related upper airways (UA) collapse. UA mechanical properties and neural control are altered imposing a mechanical load on inspiration. UA collapse does not occur during wakefulness, hence arousal-dependent compensation. Three studies in healthy and apnoeic patients allowed characterizing it. From upper-airway pressure-flow relationships, the first study described local compensation mechanisms, before and after a neurovegetative modulation based on ptérygopalatin node compression. The second study showed a respiratory-related cortical activity that could contribute to the increased neural drive to upper airway and to inspiratory muscles that has previously been described in OSAS, and could therefore contribute to the arousal-dependent compensation of upper airway abnormalities. The third study showed a sensory gating-out process of breathing sensations in OSAS that could be reversed by mandibular advancement device, allowing linking upper-airway stability improvement to central integration of respiratory sensations. Finally, upper-airway pressure-flow relationship was approached by two models

Upper airway stabilization by osteopathic manipulation of the sphenopalatine ganglion versus sham manipulation in OSAS patients: a proof-of-concept, randomized, crossover, double-blind, controlled study

Abstract Background Osteopathic manipulative treatment (OMT) of the sphenopalatine ganglion (SPG) is used empirically for the treatment of rhinitis and snoring and is thought to increase pharyngeal stability. This trial was designed to study the effects of this treatment on pharyngeal stability evaluated by critical closing pressure in obstructive sleep apnoea syndrome. Methods This single-centre, randomized, crossover, double-blind study compared active manipulation and sham manipulation of the SPG. Randomization was computer-generated. Patients each received one active manipulation and one sham manipulation at an interval of 21 days and were evaluated 30 min and 48 h after each session administered by a qualified osteopath. Neither the patients, nor the investigator performing the evaluations were informed about the order of the two techniques (double-blind). The primary endpoint was the percentage of responding patients presenting increased pharyngeal stability defined by a variation of critical closing pressure (Pcrit) of at least −4 cmH2O at 30 min. Secondary endpoints were the variation of Pcrit in absolute values, sleepiness and snoring. Others endpoints were lacrimation (Schirmer’s test), induced pain, sensations experienced during OMT. Results Ten patients were included and nine (57 [50; 58] years, comprising 7 men, with an apnoea-hypopnoea index of 31.0 [25.5; 33.2]/h; (values are median [quartiles])) were analysed. Seven patients were analysed for the primary endpoint and nine patients were analysed for secondary endpoints. Five patients responded after active manipulation versus no patients after sham manipulation (p = 0.0209). Active manipulation induced more intense pain (p = 0.0089), increased lacrimation (ns) and more tactile, nociceptive and gustatory sensations (13 versus 1) compared to sham manipulation. No significant difference was observed for the other endpoints. Conclusions Osteopathic manipulative treatment of the SPG may improve pharyngeal stability in obstructive sleep apnoea syndrome. This trial validates the feasibility of the randomized, controlled, double-blind methodology for evaluation of this osteopathic treatment. Studies on a larger sample size must specify the efficacy on the apnoea-hypopnoea index. Trial registration The study was retrospectively registered in the clinicaltrial.gov registry under reference NCT01193738 on 1st September 2010 (first inclusion May 19, 2010)