27 research outputs found

    Synthèse des journées scientifiques francophones portant sur les codes de calculs en radioprotection, radiophysique et dosimétrie

    No full text
    L’article dresse le bilan des études présentées lors des journées scientifiques francophones co-organisées le 2-3 octobre 2003 à Sochaux par la SFRP (Société française de radioprotection), la SFPM (Société française de physique médicale) et la FIRAM (Association francophone pour le développement et l’utilisation des logiciels de simulation d’interaction rayonnement matière). L’article s’attache tout particulièrement à restituer de ces journées internationales, la synthèse des tendances actuelles dans le domaine du développement et de l’utilisation des codes de calculs en radioprotection, en radiophysique et en dosimétrie

    Feasibility study of a new platform based on the Case-Based Reasoning principles to efficiently search and store voxel phantoms

    No full text
    In case of accidental exposure to radiation, it is necessary to establish as soon as possible a dosimetry report for each victim. In most cases, this report is based on medical images of the victim, enabling the construction of a personalized realistic numerical model, also called a voxel phantom. Unfortunately it is not always possible to perform the medical imaging of the victim since the technology may be unavailable or to avoid additional exposure to radiation. In such cases, the commonly used method is to represent the victim with a numerical model like the "Reference Man", a voxelized phantom representative of the average male individual. The treatment accuracy depends on the diagnosis precision and, consequently, on the similarity of the phantom and/to the victim. A precise dosimetry evaluation requires a personalised and realistic phantom whose biometric characteristics match the victim; such model is often unavailable. The Case-Based Reasoning (CBR) is a problem solving method for the conception of intelligent systems. It imitates the analysis, understanding and reconstruction of the human intelligence. The ReEPh project (Research of Equivalent Phantom) proposes to use the CBR principles to retrieve from a set of phantoms, the most adapted one to the irradiated victim. For this study, the ReEPh platform retrieves, stores and compares existing phantoms to a victim. A graphic interface enables the user to compare victim's characteristics to the ones of the most similar phantoms available in the database. This defines a similarity index presenting the equivalence between the victim and the suggested phantom. Moreover, a confidence index is also assessed to define the uncertainty implied by the RaPC choice procedure. © EDP Sciences, 2010

    Evolution du capteur électronique pour la dosimétrie des neutrons développé au LEPOFI

    No full text
    La dosimétrie neutronique des personnels à l'aide de dispositifs électroniques est étudiée depuis quelques années. Ces dispositifs offrent un avantage majeur : l'obtention d'une réponse en temps réel. Après une étude de faisabilité d'un système à double diode, fondé sur l'utilisation de la méthode différentielle, le capteur (convertisseur de polyéthylène (CH2)n avec une implantation d'ions 10B et diode silicium) a été expérimenté dans divers champs de neutrons et modélisé afin de confirmer et compléter les mesures. La contribution des photons γ de ces champs de neutrons est la principale perturbation pour la détermination de la réponse aux neutrons. La sensibilité aux neutrons Sn est de 1 impulsion cm-2 µSv-1 pour les thermiques et sur la gamme d'énergie 1,5 - 5 MeV avec un seuil énergétique à 125 keV pour les particules secondaires détectées. Lorsque les équivalents de dose γ et neutron (équivalent de dose ambient H* (10)) deviennent du même ordre de grandeur, la perte de sensibilité Sn est d'autant plus grande que la composante du spectre neutronique en dessous de 500 keV est plus importante par rapport à celle au-dessus de cette énergie. La sensibilité aux photons γ (Sγ) est de l'ordre de 300 impulsions cm-2 µSv-1 avec un seuil de coupure à 130 keV. La modélisation du capteur a été effectuée avec un code Monte-Carlo (EGS4) pour les photons γ et un programme développé au laboratoire (PNEDIOD) pour les neutrons. Une structure adéquate utilisant tous les paramètres optimisés issus de la modélisation améliorerait la discrimination (n-γ) en divisant la sensibilité Sγ par 15. Le seuil de détection énergétique de notre système pour les neutrons serait alors inférieur à 200 keV

    Epidemiology of Spine Injuries in National Collegiate Athletic Association Men's Wrestling Athletes

    No full text
    Background: Spine injuries are common in collegiate wrestlers and can lead to reinjury, persistent pain, and time lost from participation. Purpose: To describe the epidemiology of spine injuries in National Collegiate Athletic Association (NCAA) wrestlers between academic years 2009 to 2010 and 2013 to 2014. Study Design: Descriptive epidemiology study. Methods: The incidence and characteristics of spine injuries were identified utilizing the NCAA-Injury Surveillance Program database. Spine injuries were assessed for injury type, injury mechanism, time of season, event type, recurrence, participation restriction, and time lost from participation. Rates of injury were calculated as the number of injuries divided by the total number of athlete-exposures (AEs). Injury rate ratios (IRRs) were calculated for event type and time of season, and results with 95% confidence intervals that did not include 1.0 were considered statistically significant. Results: There were an estimated 2040 spine injuries reported in the database over the 4-year period, resulting in an injury rate of 0.71 per 1000 AEs. Spine injuries were over twice as likely to occur in competitions as in practices (IRR, 2.02; 95% confidence interval, 1.10-3.69). More injuries occurred in both the preseason (0.94 per 1000 AEs) and the postseason (1.12 per 1000 AEs) compared with the regular season (0.55 per 1000 AEs). Contact injuries (42%) were the most common mechanism of injury, and brachial plexus injury (20%) was the most common diagnosis. Only 1.3% of injuries required surgery, and athletes most commonly returned to sport within 24 hours (33%) or within 6 days (25%). Conclusion: This investigation found an overall injury rate of 0.71 per 1000 AEs in wrestling athletes between academic years 2009 to 2010 and 2013 to 2014. The majority of these injuries were new, and athletes most commonly returned to sport within 24 hours. The injury rate was highest in competition, and both the preseason and the postseason showed a higher injury rate than that in season. Efforts to improve injury prevention and management should be informed by these findings

    Arthroscopic Evaluation of Knee Cartilage Using Optical Reflection Spectroscopy

    No full text
    Articular cartilage is critical for painless and low-friction range of motion; however, disruption of articular cartilage, particularly in the knee joint, is common. Treatment options are based on the size and depth of the chondral defect, as well as involvement of subchondral bone. The gold standard for evaluation of articular cartilage is with arthroscopy, but it is limited by its ability to objectively judge the depth and severity of chondral damage. Optical reflection spectroscopy has been introduced to objectively assess the thickness of cartilage. We present a technique to systematically evaluate the articular cartilage of the knee using BioOptico optical reflection spectroscopy (Arthrex) to better evaluate those with visible chondral and subchondral defects
    corecore