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Image Acquisition Protocols
Published in Michael Ljungberg, Handbook of Nuclear Medicine and Molecular Imaging for Physicists, 2022
A typical rectangular detector has a scintillation crystal of approximately 40 × 50 cm. Inevitably, image quality will be poorer at the edge of the crystal and the collimator masks events from the edges. The exposed area of the crystal, for which collimator holes are present, is called the geometric field of view (GFOV) and will vary depending on collimator type. The geometric field of view does not necessarily define the final image size, and a further electronic mask defining the useful field of view (UFOV) is often applied by manufacturers. A central field of view, with dimensions 75 per cent of the UFOV is also often defined, most commonly when reporting performance parameters, which are generally better in the central region of the detector. In many cases the anatomy being imaged will be smaller than the UFOV or CFOV of the detector. It is therefore unnecessary to acquire data covering the whole detector surface and a further digital zoom can be applied to mask out the unnecessary space. Whilst the physical resolution of the camera is not changed in this process, for the same matrix size, the pixel size will reduce.
Methods for assigning impairment
Published in Ramar Sabapathi Vinayagam, Integrated Evaluation of Disability, 2019
The International Council of Ophthalmology recommends visual standards for driving safety namely visual acuity of 20/40 (0.5, 6/12), a binocular visual field of at least 120° horizontal and 40° vertical. The other visual function evaluation includes glare sensitivity, Useful Field of View (UFOV), diplopia, color vision, and night vision. Persons with monocular vision adapts well within about six months for depth perception (145).
Rehabilitation of Slowed Information Processing
Published in Barbara A. Wilson, Jill Winegardner, Caroline M. van Heugten, Tamara Ownsworth, Neuropsychological Rehabilitation, 2017
The most comprehensive study in this field is the longitudinal ACTIVE study (Rebok et al., 2014). In this study, a randomised, controlled, single-blind trial, ten training sessions for memory, reasoning or speed of information processing were offered to healthy older adults. In the speed of information processing subgroup, consisting of 702 subjects with a mean age of 74 years, these sessions lasted 60–75 minutes and entailed a computerised speed of information processing programme. Participants in the first and second training conditions received memory strategy training (n=703) and non-computerised reasoning training (n=699) respectively. A control group (n=698) had no training at all. A proportion of each trained subgroup (about 40 per cent) also had booster sessions after 11 and 35 months post-intervention. Speed of processing training, presented via computer, focused on visual search and the ability to process increasingly more complex information presented in successively shorter presentation times. The effects were followed up until ten years after training with three sets of assessment: (1) Useful Field of View (UFOV) tasks requiring identification and localisation of information, with 75 per cent accuracy, under varying levels of cognitive demand; (2) self-report measures of everyday instrumental activities of daily living (IADL) difficulties; and (3) two performance-based measures of daily function (e.g. Timed IADL).
Ready for a Learner’s Permit? Clinical Neuropsychological Off-road Tests and Driving Behaviors in a Simulator among Adolescents with ADHD and ASD
Published in Developmental Neurorehabilitation, 2021
H Selander, N Strand, M Almberg, B Lidestam
Some cognitive tests are considered more valuable and useful for screening patients and for guiding clinical practice when determining fitness to drive, such as the Useful Field of View (UFOV) test.17 The UFOV test is a PC-based visual and cognitive test of the visual field over which a person can process visual information, and the test performance relies on higher-order cognitive abilities as well as visual (sensory and perceptual) function.18 The UFOV test has been associated with driving competence in older drivers in numerous studies.19 Among older drivers, visual field loss from stroke is not uncommon, both diagnosed and undiagnosed. However, considerably less research has been done on this with regard to younger or novice drivers.20,21 Hypothetically and because of their reliance on higher-order cognitive processing, the functional impairments of ADHD related to attention, hyperactivity, inattention, and impulse control should be reflected in the performance in the UFOV test. The Test of Variables of Attention (TOVA) is a neuropsychological test of concentration, impulsivity, response time, speed of processing, and inattention.22,23 The TOVA has proven sensitive for identifying ADHD-like symptoms,23 but was not developed as a tool for fitness-to-drive assessment. However, on-road assessments cannot be included because the assessment needs to be completed before a learner’s permit is issued. For clinical practice, fitness-to-drive decisions may be challenging for this group of patients due to lack of guidelines, evidence, and test norms.
Portrait of driving practice following a mild stroke: a secondary analysis of a chart audit
Published in Topics in Stroke Rehabilitation, 2020
Marie-Andrée Ouellet, Annie Rochette, Carole Miéville, Lise Poissant
Several pre-driving assessments have demonstrated good validity and relevance for clinical use with stroke patients. Indeed, Devos and collaborators8 concluded that the Road Sign Recognition Test, the Compass and the Trail Making Test B (TMT B) identify drivers at risk of failing a road test with an accuracy corresponding to 84%, 85%, and 80%, respectively. Furthermore, Marshall and colleagues9 demonstrated that Trail Making Test A and B (TMT A and TMT B) and Taylor Complex Figure Design as well as Useful Field of View Test (UFOV) and Motor-Free Visual Perception Test (MVPT) are the most predictive nonspecific driving assessments. Finally, the Montreal Cognitive Assessment10 can be a rapid screening tool to be administered in a clinic to assist professionals in making decisions related to the need for a more thorough driving assessment: the threshold score ≤ 11/30 indicates a high risk of failing a road test and a score between 12 and 27 implies a 50% risk of failure on the same test.11 The driving-specific assessment tools that have demonstrated good validity, reliability, and ease of use with an older clientele and were recommended consisted of the Cognitive Behavorial Driver’s Inventory (CBDI), DriveABLE Competence Screen, UFOV and Stroke Driver Screening Assessment (SDSA).12
A pre/post evaluation of fatigue, stress and vigilance amongst commercially licensed truck drivers performing a prolonged driving task
Published in International Journal of Occupational Safety and Ergonomics, 2019
Michelle Cardoso, Fred Fulton, Jack P. Callaghan, Michel Johnson, Wayne J. Albert
Speed of information processing, divided attention and selective attention were measured using a useful field of view (UFOV) computer test. The UFOV is a tool that monitors information processing without the participants needing to move their head or eyes. Following Parasuraman et al.’s [27,28] definition of vigilance, the ability to sustain attention and to remain alert to stimuli/a task for a period of time, a drop in attention (UFOV) scores over the course of the study would suggests a decrement in vigilance. The UFOV test requires the user to identify and localize one of two objects (car or truck) throughout three different tests. The first subtest measures information processing by flashing the image of a car or truck in a central location of the screen and the participants must identify the stimuli. The second subtest monitors dividing attention by showing an image (car or truck) in a central location along with a peripheral object (placed in one of eight possible locations). Participants are required to recall the image in the central location and report the location of the peripheral object. The third subtest monitors the susceptibility to distraction; the second subtest is repeated but is now coupled with distractions [29]. Participants were required to complete the UFOV test pre/post the simulated driving tasks, meaning this test was completed during four different time points (trials): T1, pre driver simulation 1; T2, post driver simulation 1; T3, pre driver simulation 2; T4, post driver simulation 2 (Figure 4).