141 resultados para swd: Head-mounted Display
em Université de Lausanne, Switzerland
Resumo:
In the health domain, the field of rehabilitation suffers from a lack specialized staff while hospital costs only increase. Worse, almost no tools are dedicated to motivate patients or help the personnel to carry out monitoring of therapeutic exercises. This paper demonstrates the high potential that can bring the virtual reality with a platform of serious games for the rehabilitation of the legs involving a head-mounted display and haptic robot devices. We first introduce SG principles and the current context regarding rehabilitation interventions followed by the description of an original haptic device called Lambda Health System. The architecture of the model is then detailed, including communication specifications showing that lag is imperceptible for user (60Hz). Finally, four serious games for rehabilitation using haptic robots and/or HMD were tested by 33 health specialists.
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BACKGROUND: Visual behavior is known to be atypical in Autism Spectrum Disorders (ASD). Monitor-based eye-tracking studies have measured several of these atypicalities in individuals with Autism. While atypical behaviors are known to be accentuated during natural interactions, few studies have been made on gaze behavior in natural interactions. In this study we focused on i) whether the findings done in laboratory settings are also visible in a naturalistic interaction; ii) whether new atypical elements appear when studying visual behavior across the whole field of view. METHODOLOGY/PRINCIPAL FINDINGS: Ten children with ASD and ten typically developing children participated in a dyadic interaction with an experimenter administering items from the Early Social Communication Scale (ESCS). The children wore a novel head-mounted eye-tracker, measuring gaze direction and presence of faces across the child's field of view. The analysis of gaze episodes to faces revealed that children with ASD looked significantly less and for shorter lapses of time at the experimenter. The analysis of gaze patterns across the child's field of view revealed that children with ASD looked downwards and made more extensive use of their lateral field of view when exploring the environment. CONCLUSIONS/SIGNIFICANCE: The data gathered in naturalistic settings confirm findings previously obtained only in monitor-based studies. Moreover, the study allowed to observe a generalized strategy of lateral gaze in children with ASD when they were looking at the objects in their environment.
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Using head-mounted eye tracker material, we assessed spatial recognition abilities (e.g., reaction to object permutation, removal or replacement with a new object) in participants with intellectual disabilities. The "Intellectual Disabilities (ID)" group (n=40) obtained a score totalling a 93.7% success rate, whereas the "Normal Control" group (n=40) scored 55.6% and took longer to fix their attention on the displaced object. The participants with an intellectual disability thus had a more accurate perception of spatial changes than controls. Interestingly, the ID participants were more reactive to object displacement than to removal of the object. In the specific test of novelty detection, however, the scores were similar, the two groups approaching 100% detection. Analysis of the strategies expressed by the ID group revealed that they engaged in more systematic object checking and were more sensitive than the control group to changes in the structure of the environment. Indeed, during the familiarisation phase, the "ID" group explored the collection of objects more slowly, and fixed their gaze for a longer time upon a significantly lower number of fixation points during visual sweeping.
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BACKGROUND: Only a few studies have explored the relation between coffee and tea intake and head and neck cancers, with inconsistent results. METHODS: We pooled individual-level data from nine case-control studies of head and neck cancers, including 5,139 cases and 9,028 controls. Logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (95% CI), adjusting for potential confounders. RESULTS: Caffeinated coffee intake was inversely related with the risk of cancer of the oral cavity and pharynx: the ORs were 0.96 (95% CI, 0.94-0.98) for an increment of 1 cup per day and 0.61 (95% CI, 0.47-0.80) in drinkers of >4 cups per day versus nondrinkers. This latter estimate was consistent for different anatomic sites (OR, 0.46; 95% CI, 0.30-0.71 for oral cavity; OR, 0.58; 95% CI, 0.41-0.82 for oropharynx/hypopharynx; and OR, 0.61; 95% CI, 0.37-1.01 for oral cavity/pharynx not otherwise specified) and across strata of selected covariates. No association of caffeinated coffee drinking was found with laryngeal cancer (OR, 0.96; 95% CI, 0.64-1.45 in drinkers of >4 cups per day versus nondrinkers). Data on decaffeinated coffee were too sparse for detailed analysis, but indicated no increased risk. Tea intake was not associated with head and neck cancer risk (OR, 0.99; 95% CI, 0.89-1.11 for drinkers versus nondrinkers). CONCLUSIONS: This pooled analysis of case-control studies supports the hypothesis of an inverse association between caffeinated coffee drinking and risk of cancer of the oral cavity and pharynx. IMPACT: Given widespread use of coffee and the relatively high incidence and low survival of head and neck cancers, the observed inverse association may have appreciable public health relevance.
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PURPOSE: To understand the reasons for differences in the delineation of target volumes between physicians. MATERIAL AND METHODS: 18 Swiss radiooncology centers were invited to delineate volumes for one prostate and one head-and-neck case. In addition, a questionnaire was sent to evaluate the differences in the volume definition (GTV [gross tumor volume], CTV [clinical target volume], PTV [planning target volume]), the various estimated margins, and the nodes at risk. Coherence between drawn and stated margins by centers was calculated. The questionnaire also included a nonspecific series of questions regarding planning methods in each institution. RESULTS: Fairly large differences in the drawn volumes were seen between the centers in both cases and also in the definition of volumes. Correlation between drawn and stated margins was fair in the prostate case and poor in the head-and-neck case. The questionnaire revealed important differences in the planning methods between centers. CONCLUSION: These large differences could be explained by (1) a variable knowledge/interpretation of ICRU definitions, (2) variable interpretations of the potential microscopic extent, (3) difficulties in GTV identification, (4) differences in the concept, and (5) incoherence between theory (i.e., stated margins) and practice (i.e., drawn margins).
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BACKGROUND: Increasing incidence of head and neck cancer (HNC) in young adults has been reported. We aimed to compare the role of major risk factors and family history of cancer in HNC in young adults and older patients. METHODS: We pooled data from 25 case-control studies and conducted separate analyses for adults ≤45 years old ('young adults', 2010 cases and 4042 controls) and >45 years old ('older adults', 17 700 cases and 22 704 controls). Using logistic regression with studies treated as random effects, we estimated adjusted odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: The young group of cases had a higher proportion of oral tongue cancer (16.0% in women; 11.0% in men) and unspecified oral cavity / oropharynx cancer (16.2%; 11.1%) and a lower proportion of larynx cancer (12.1%; 16.6%) than older adult cases. The proportions of never smokers or never drinkers among female cases were higher than among male cases in both age groups. Positive associations with HNC and duration or pack-years of smoking and drinking were similar across age groups. However, the attributable fractions (AFs) for smoking and drinking were lower in young when compared with older adults (AFs for smoking in young women, older women, young men and older men, respectively, = 19.9% (95% CI = 9.8%, 27.9%), 48.9% (46.6%, 50.8%), 46.2% (38.5%, 52.5%), 64.3% (62.2%, 66.4%); AFs for drinking = 5.3% (-11.2%, 18.0%), 20.0% (14.5%, 25.0%), 21.5% (5.0%, 34.9%) and 50.4% (46.1%, 54.3%). A family history of early-onset cancer was associated with HNC risk in the young [OR = 2.27 (95% CI = 1.26, 4.10)], but not in the older adults [OR = 1.10 (0.91, 1.31)]. The attributable fraction for family history of early-onset cancer was 23.2% (8.60% to 31.4%) in young compared with 2.20% (-2.41%, 5.80%) in older adults. CONCLUSIONS: Differences in HNC aetiology according to age group may exist. The lower AF of cigarette smoking and alcohol drinking in young adults may be due to the reduced length of exposure due to the lower age. Other characteristics, such as those that are inherited, may play a more important role in HNC in young adults compared with older adults.
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Cancer-testis (CT) antigens comprise families of tumor-associated antigens that are immunogenic in patients with various cancers. Their restricted expression makes them attractive targets for immunotherapy. The aim of this study was to determine the expression of several CT genes and evaluate their prognostic value in head and neck squamous cell carcinoma (HNSCC). The pattern and level of expression of 12 CT genes (MAGE-A1, MAGE-A3, MAGE-A4, MAGE-A10, MAGE-C2, NY-ESO-1, LAGE-1, SSX-2, SSX-4, BAGE, GAGE-1/2, GAGE-3/4) and the tumor-associated antigen encoding genes PRAME, HERV-K-MEL, and NA-17A were evaluated by RT-PCR in a panel of 57 primary HNSCC. Over 80% of the tumors expressed at least 1 CT gene. Coexpression of three or more genes was detected in 59% of the patients. MAGE-A4 (60%), MAGE-A3 (51%), PRAME (49%) and HERV-K-MEL (42%) were the most frequently expressed genes. Overall, the pattern of expression of CT genes indicated a coordinate regulation; however there was no correlation between expression of MAGE-A3/A4 and BORIS, a gene whose product has been implicated in CT gene activation. The presence of MAGE-A and NY-ESO-1 proteins was verified by immunohistochemistry. Analysis of the correlation between mRNA expression of CT genes with clinico-pathological characteristics and clinical outcome revealed that patients with tumors positive for MAGE-A4 or multiple CT gene expression had a poorer overall survival. Furthermore, MAGE-A4 mRNA positivity was prognostic of poor outcome independent of clinical parameters. These findings indicate that expression of CT genes is associated with a more malignant phenotype and suggest their usefulness as prognostic markers in HNSCC.
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Replacement of the hyperimmune anti-Rhesus (Rh) D immunoglobulin, currently used to prevent haemolytic disease of the newborn, by fully recombinant human anti-RhD antibodies would solve the current logistic problems associated with supply and demand. The combination of phage display repertoire cloning with precise selection procedures enables isolation of specific genes that can then be inserted into mammalian expression systems allowing production of large quantities of recombinant human proteins. With the aim of selecting high-affinity anti-RhD antibodies, two human Fab libraries were constructed from a hyperimmune donor. Use of a new phage panning procedure involving bromelin-treated red blood cells enabled the isolation of two high-affinity Fab-expressing phage clones. LD-6-3 and LD-6-33, specific for RhD. These showed a novel reaction pattern by recognizing the D variants D(III), D(IVa), D(IVb), D(Va), D(VI) types I and II. D(VII), Rh33 and DFR. Full-length immunoglobulin molecules were constructed by cloning the variable regions into expression vectors containing genomic DNA encoding the immunoglobulin constant regions. We describe the first, stable, suspension growth-adapted Chinese hamster ovary (CHO) cell line producing a high affinity recombinant human IgG1 anti-RhD antibody adapted to pilot-scale production. Evaluation of the Fc region of this recombinant antibody by either chemiluminescence or antibody-dependent cell cytotoxicity (ADCC) assays demonstrated macrophage activation and lysis of red blood cells by human lymphocytes. A consistent source of recombinant human anti-RhD immunoglobulin produced by CHO cells is expected to meet the stringent safety and regulatory requirements for prophylactic application.
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OBJECTIVE: To assess the feasibility and efficacy of subcutaneous amifostine therapy in patients with head and neck cancer treated with curative accelerated radiotherapy (RT). DESIGN: Retrospective study. SETTING: University of Lausanne, Lausanne, Switzerland. PATIENTS: Thirty-three consecutive patients (male-female ratio, 4.5; median age, 54 years [age range, 39-76 years]). INTERVENTIONS: Between November 2000 and January 2003, the 33 patients were treated with curative definitive (n = 19) or postoperative (n = 14) RT with (n = 26) or without (n = 7) chemotherapy. All patients received conformal RT. Fractionation schedule consisted of concomitant-boost (Friday afternoon session) accelerated RT using 70 Gy (2 Gy per fraction) in 6 weeks in patients treated with definitive RT and 66 Gy (2 Gy per fraction) in 5 weeks and 3 days in the postoperative setting. Parotid glands received at least 50 Gy in all patients. Amifostine was administered to a total dose of 500 mg subcutaneously, 15 to 30 minutes before morning RT sessions. RESULTS: All patients received their planned treatment (including chemotherapy). Ten patients received the full schedule of amifostine (at least 25 injections), 9 received 20 to 24 doses, 4 received 10 to 19 doses, 5 received 5 to 9 doses, and 5 received fewer than 5 doses. Fifteen patients (45%) did not show any intolerance related to amifostine use. Amifostine therapy was discontinued because of nausea in 11 patients (33%) and hypotension in 6 patients (18%), and 1 patient refused treatment. No grade 3, amifostine-related, cutaneous toxic effects were observed. Radiotherapy-induced grade 3 acute toxic effects included mucositis in 14 patients (42%), erythema in 14 patients (42%), and dysphagia in 13 patients (39%). Late toxic effects included grade 2 or more xerostomia in 17 patients (51%) and fibrosis in 3 patients (9%). Grade 2 or more xerostomia was observed in 8 (42%) of 19 patients receiving 20 injections or more vs 9 (64%) of 14 patients receiving fewer than 20 injections (P = .15). CONCLUSIONS: Subcutaneous amifostine administration in combination with accelerated concomitant-boost RT with or without chemotherapy is feasible. The major adverse effect of subcutaneous administration was nausea despite prophylactic antiemetic medication, and hypotension was observed in only 6 patients (18%).
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This work explores a concept for motion detection in brain MR examinations using high channel-count RF coil arrays. It applies ultrashort (<100 μsec) free induction decay signals, making use of the knowledge that motion induces variations in these signals when compared to a reference free induction decay signal. As a proof-of-concept, the method was implemented in a standard structural MRI sequence. The stability of the free induction decay-signal was verified in phantom experiments. Human experiments demonstrated that the observed variations in the navigator data provide a sensitive measure for detection of relevant and common subject motion patterns. The proposed methodology provides a means to monitor subject motion throughout a MRI scan while causing little or no impact on the sequence timing and image contrast. It could hence complement available motion detection and correction methods, thus further reducing motion sensitivity in MR applications.
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Dès le milieu des années 1920 et le développement des premiers prototypes fonctionnels, la télévision se fait objet d'exposition. La nouvelle technologie est montrée à des foires industrielles et dans des grands magasins, à des expositions universelles et nationales : exposée, la télévision devient un mass media avant même qu'elle ne diffuse des émissions régulières. En étudiant les présentations publiques de la télévision en Allemagne, en Grande-Bretagne et aux Etats-Unis entre 1928 - date de l'ouverture des premières expositions annuelles dans les trois pays - et 1939 - moment de l'interruption de celles-ci suite à l'éclatement de la Deuxième Guerre mondiale - Television before TV montre que les lieux où le médium rencontre son premier public constituent les mêmes espaces qui, rétrospectivement, permettent de comprendre son avènement. Cette recherche propose ainsi de nouvelles pistes pour l'histoire des médias en interrogeant la définition de la télévision en tant que médium du privé. Elle rappelle l'importance historique de l'espace public pour la « vision à distance » et, dépassant la perspective nationale, reconstitue les différences et similarités techniques, médiatiques et institutionnelles de la télévision allemande, américaine et britannique dans l'entre-deux-guerres. Développée dans un contexte qui est simultanément nationaliste et nourri d'échanges et de compétitions internationales, la télévision sert de comparatif dans les rivalités entre pays, mais stimule également la circulation de savoir-faire et de personnes. Sa forte valeur symbolique comme emblème du progrès scientifique et, dans le cas allemand, comme preuve de la modernité du régime national-socialiste se traduit dans les salles d'expositions par des scénographies souvent innovatrices, dont les photographies et descriptions se propagent au-delà de la presse locale. Au centre d'un réseau discursif et représentationnel, les expositions jouent alors un rôle essentiel pour la construction sociale, politique et culturelle de la télévision. Remplaçant l'analyse de textes audiovisuels par l'étude de la machine exposée, ma recherche reformule la question bazinienne de qu'est-ce que la télévision ? pour demander où le médium se situe-t-il ? Cette prémisse méthodologique permet de contourner une évaluation qualitative de la technologie qui déplorerait ses multiples imperfections, et éclaire d'un nouveau jour des dispositifs télévisuels qui, même sans programme, intègrent un univers voué à la culture de consommation et du loisir.
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New anti-cancer agents are being developed that specifically recognise tumour cells. Recognition is dependent upon the enhanced expression of antigenic determinants on the surface of tumour cells. The tumour exposure and the extracellular accessibility of the mucin MUC-1 make this marker a suitable target for tumour diagnosis and therapy. We isolated and characterised six human scFv antibody fragments that bound to the MUC-1 core protein, by selecting a large naive human phage display library directly on a MUC-1-expressing breast carcinoma cell line. Their binding characteristics have been studied by ELISA, FACS and indirect immunofluorescence. The human scFv antibody fragments were specific for the tandem repeat region of MUC-1 and their binding is inhibited by soluble antigen. Four human scFv antibody fragments (M2, M3, M8, M12) recognised the hydrophilic PDTRP region of the MUC-1 core protein, which is thought to be an immunodominant region. The human scFv antibody fragments were stable in human serum at 37 degrees C and retained their binding specificity. For imaging or targeting to tumours over-expressing MUC-1, it might be feasible to use these human scFv, or multivalent derivatives, as vehicles to deliver anti-cancer agents.
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In order to evaluate the effect of head injury in severely traumatized patients on the response of ACTH, GH, PRL, and TSH plasma levels, 36 patients were prospectively studied over 5 consecutive days following injury. They were divided into three groups: Group I, severe isolated head injury (n = 14); Group II, multiple injury combined with severe head injury (n = 12); Group III, multiple injury without head injury (n = 10). No significant trend was observed during the 5 consecutive days. The following changes in plasma levels were observed, compared to normal reference value (median values): ACTH was normal in the three groups; PRL was elevated in Group II and normal in the other groups; GH was elevated in all groups; TSH was elevated in Group III and reduced in Groups I and II. Intergroup comparisons showed significantly lower plasma levels for PRL (p less than 0.05) and TSH (p less than 0.01) in Groups I and II, i.e., head-injured patients, compared to Group III, i.e., traumatized patients without head injury. A relationship was observed between the severity of head injury, as expressed by Glasgow Coma Score, intracranial pressure levels, outcome, and TSH and PRL levels.
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Purpose Third generation anatomic total shoulder prostheses offer a wide range of adaptability (size, thickness, retroversion and offset of the humeral head, cervico-diaphyseal angle) in order to reproduce anatomy and biomechanics of the shoulder as normal as possible. The large variability of the implants may also induce malposition. Our goal was to analyse the consequences of a humeral head malposition, which is one of the most frequent placement errors. Material and Methods A 3D finite element model of the glenohumeral joint, including the rotator cuff muscles and the deltoid, was used with the Aequalis anatomic prosthesis. Active abduction was simulated. Three humeral head placements were compared : anatomic positioning (A), 5 mm inferior positioning (B), 5 mm superior positioning (C). The effect of humeral head malposition was evaluated through the following quantities : the range of motion free of impingements, the glenohumeral contact pattern, and the stress within the polyethylene and the cement. Results Inferior positioning (B) of the humeral head produced a superior impingement before 90° of abduction, an inferior eccentric contact point on the glenoid, and 165% increase of cement stress. Superior positioning (C) of the humeral head produced a postero-superior eccentric contact point on the glenoid, 300% increase of glenohumeral contact pressure, 450% increase of polyethylene stress, and 207% increase of cement stress. Conclusion Malposition of the humeral head of anatomic prostheses induces biomechanical consequences that may preclude the glenoid survival. Particular attention must be paid to reproduce the humeral anatomy as normal as possible.