223 research outputs found

    An investigation of the visual sampling behaviour of human observers

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    Visual sampling behavior of human observers for aerospace vehicle design application

    Owl and Lizard: Patterns of Head Pose and Eye Pose in Driver Gaze Classification

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    Accurate, robust, inexpensive gaze tracking in the car can help keep a driver safe by facilitating the more effective study of how to improve (1) vehicle interfaces and (2) the design of future Advanced Driver Assistance Systems. In this paper, we estimate head pose and eye pose from monocular video using methods developed extensively in prior work and ask two new interesting questions. First, how much better can we classify driver gaze using head and eye pose versus just using head pose? Second, are there individual-specific gaze strategies that strongly correlate with how much gaze classification improves with the addition of eye pose information? We answer these questions by evaluating data drawn from an on-road study of 40 drivers. The main insight of the paper is conveyed through the analogy of an "owl" and "lizard" which describes the degree to which the eyes and the head move when shifting gaze. When the head moves a lot ("owl"), not much classification improvement is attained by estimating eye pose on top of head pose. On the other hand, when the head stays still and only the eyes move ("lizard"), classification accuracy increases significantly from adding in eye pose. We characterize how that accuracy varies between people, gaze strategies, and gaze regions.Comment: Accepted for Publication in IET Computer Vision. arXiv admin note: text overlap with arXiv:1507.0476

    Behavioural compensation by drivers of a simulator when using a vision enhancement system

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    Technological progress is suggesting dramatic changes to the tasks of the driver, with the general aim of making driving environment safer. Before any of these technologies are implemented, empirical research is required to establish if these devices do, in fact, bring about the anticipated improvements. Initially, at least, simulated driving environments offer a means of conducting this research. The study reported here concentrates on the application of a vision enhancement (VE) system within the risk homeostasis paradigm. It was anticipated, in line with risk homeostasis theory, that drivers would compensate for the reduction in risk by increasing speed. The results support the hypothesis although, after a simulated failure of the VE system, drivers did reduce their speed due to reduced confidence in the reliability of the system

    Epiglottis reshaping using CO2 laser: A minimally invasive technique and its potent applications

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    Laryngomalacia (LRM), is the most common laryngeal abnormality of the newborn, caused by a long curled epiglottis, which prolapses posteriorly. Epiglottis prolapse during inspiration (acquired laryngomalacia) is an unusual cause of airway obstruction and a rare cause of obstructive sleep apnea syndrome (OSAS)

    Three-Year Follow-up of 2-Dose Versus 3-Dose HPV Vaccine

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    BACKGROUND AND OBJECTIVES: Human papillomavirus (HPV) antibody responses to the 9-valent abstract human papillomavirus (9vHPV) vaccine among girls and boys (aged 9–14 years) receiving 2- dose regimens (months 0, 6 or 0, 12) were noninferior to a 3-dose regimen (months 0, 2, 6) in young women (aged 16–26 years) 4 weeks after last vaccination in an international, randomized, open-label trial (NCT01984697). We assessed response durability through month 36. METHODS: Girls received 2 (months 0 and 6 [0, 6]: n = 301; months 0 and 12 [0, 12]: n = 151) or 3 doses (months 0,2, and 6 [0, 2, 6]: n = 301); boys received 2 doses ([0, 6]: n = 301; [0, 12]: n = 150); and young women received 3 doses ([0, 2, 6]: n = 314) of 9vHPV vaccine. Anti-HPV geometric mean titers (GMTs) were assessed by competitive Luminex immunoassay (cLIA) and immunoglobulin G-Luminex immunoassay (IgG-LIA) through month 36. RESULTS: Anti-HPV GMTs were highest 1 month after the last 9vHPV vaccine regimen dose, decreased sharply during the subsequent 12 months, and then decreased more slowly. GMTs 2 to 2.5 years after the last regimen dose in girls and boys given 2 doses were generally similar to or greater than GMTs in young women given 3 doses. Across HPV types, most boys and girls who received 2 doses (cLIA: 81%–100%; IgG-LIA: 91%–100%) and young women who received 3 doses (cLIA: 78%–98%; IgG-LIA: 91%–100%) remained seropositive 2 to 2.5 years after the last regimen dose. CONCLUSIONS: Antibody responses persisted through 2 to 2.5 years after the last dose of a 2-dose 9vHPV vaccine regimen in girls and boys. In girls and boys, antibody responses generated by 2 doses administered 6 to 12 months apart may be sufficient to induce high-level protective efficacy through at least 2 years after the second dose.Medicin

    Polypharmacy and Quality of Life Among Dialysis Patients: A Qualitative Study

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    RATIONALE & OBJECTIVE: Almost all patients who receive dialysis experience polypharmacy, but little is known about their experiences with medication or perceptions toward it. In this qualitative study, we aimed to gain insight into dialysis patients' experiences with polypharmacy, the ways they integrate their medication into their daily lives, and the ways it affects their quality of life. STUDY DESIGN: Qualitative study using semistructured interviews. SETTING & PARTICIPANTS: Patients who received dialysis from 2 Dutch university hospitals. ANALYTICAL APPROACH: Interviews were transcribed verbatim and analyzed independently by 2 researchers through thematic content analysis. RESULTS: Overall, 28 individuals were interviewed (29% women, mean age 63 ± 16 years, median dialysis vintage 25.5 [interquartile range, 15-48] months, mean daily number of medications 10 ± 3). Important themes were as follows: (1) their own definition of what constitutes "medication," (2) their perception of medication, (3) medication routines and their impact on daily (quality of) life, and (4) interactions with health care professionals and others regarding medication. Participants generally perceived medication as burdensome but less so than dialysis. Medication was accepted as an essential precondition for their health, although participants did not always notice these health benefits directly. Medication routines and other coping mechanisms helped participants reduce the perceived negative effects of medication. In fact, medication increased freedom for some participants. Participants generally had constructive relationships with their physicians when discussing their medication. LIMITATIONS: Results are context dependent and might therefore not apply directly to other contexts. CONCLUSIONS: Polypharmacy negatively affected dialysis patients' quality of life, but these effects were overshadowed by the burden of dialysis. The patients' realization that medication is important to their health and effective coping strategies mitigated the negative impact of polypharmacy on their quality of life. Physicians and patients should work together continuously to evaluate the impact of treatments on health and other aspects of patients' daily lives. PLAIN-LANGUAGE SUMMARY: People receiving dialysis treatment are prescribed a large number of medications (polypharmacy). Polypharmacy is associated with a number of issues, including a lower health-related quality of life. In this study we interviewed patients who received dialysis treatment to understand how they experience polypharmacy in the context of their daily lives. Participants generally perceived medication as burdensome but less so than dialysis and accepted medication as an essential precondition for their health. Medication routines and other coping mechanisms helped participants mitigate the perceived negative effects of medication. In fact, medication led to increased freedom for some participants. Participants had generally constructive relationships with their physicians when discussing their medication but felt that physicians sometimes do not understand them

    Orally administered 5-aminolevulinic acid for isolation and characterization of circulating tumor-derived extracellular vesicles in glioblastoma patients

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    Background: In glioblastoma (GB), tissue is required for accurate diagnosis and subtyping. Tissue can be obtained through resection or (stereotactic) biopsy, but these invasive procedures provide risks for patients. Extracellular vesicles (EVs) are small, cell-derived vesicles that contain miRNAs, proteins, and lipids, and possible candidates for liquid biopsies. GB-derived EVs can be found in the blood of patients, but it is difficult to distinguish them from circulating non-tumor EVs. 5-aminolevulinic acid (5-ALA) is orally administered to GB patients to facilitate tumor visualization and maximal resection, as it is metabolized to fluorescent protoporphyrin IX (PpIX) that accumulates in glioma cell

    Automatic assessment of glioma burden: A deep learning algorithm for fully automated volumetric and bi-dimensional measurement

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    Background Longitudinal measurement of glioma burden with MRI is the basis for treatment response assessment. In this study, we developed a deep learning algorithm that automatically segments abnormal fluid attenuated inversion recovery (FLAIR) hyperintensity and contrast-enhancing tumor, quantitating tumor volumes as well as the product of maximum bidimensional diameters according to the Response Assessment in Neuro-Oncology (RANO) criteria (AutoRANO). Methods Two cohorts of patients were used for this study. One consisted of 843 preoperative MRIs from 843 patients with low- or high-grade gliomas from 4 institutions and the second consisted of 713 longitudinal postoperative MRI visits from 54 patients with newly diagnosed glioblastomas (each with 2 pretreatment “baseline” MRIs) from 1 institution. Results The automatically generated FLAIR hyperintensity volume, contrast-enhancing tumor volume, and AutoRANO were highly repeatable for the double-baseline visits, with an intraclass correlation coefficient (ICC) of 0.986, 0.991, and 0.977, respectively, on the cohort of postoperative GBM patients. Furthermore, there was high agreement between manually and automatically measured tumor volumes, with ICC values of 0.915, 0.924, and 0.965 for preoperative FLAIR hyperintensity, postoperative FLAIR hyperintensity, and postoperative contrast-enhancing tumor volumes, respectively. Lastly, the ICCs for comparing manually and automatically derived longitudinal changes in tumor burden were 0.917, 0.966, and 0.850 for FLAIR hyperintensity volume, contrast-enhancing tumor volume, and RANO measures, respectively. Conclusions Our automated algorithm demonstrates potential utility for evaluating tumor burden in complex posttreatment settings, although further validation in multicenter clinical trials will be needed prior to widespread implementation
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