372 research outputs found
POSITION CONCORDANT - HAPTIC MOUSE
Haptic mice, computer mice modified to have a tactile display, have been developed to enable access to computer graphics by individuals who are blind or visually impaired. Although these haptic mice are potentially very helpful and have been frequently used by the research community, there are some fundamental problems with the mouse, limiting its acceptance. In this paper we have identified the problems and have suggested solutions using one haptic mouse, the VT Player. We found that our modified VT Player showed significant improvement both in terms of the odds of obtaining a correct responses and the time to perform the tasks
A STUDY TOWARDS DEVELOPMENT OF AN AUTOMATED HAPTIC USER INTERFACE (AHUI) FOR INDIVIDUALS WHO ARE BLIND OR VISUALLY IMPAIRED
An increasing amount of information content used in schools, work and everyday living is being presented in graphical form, creating accessibility challenges for individuals who are blind or visually impaired, especially in dynamic environments, such as over the internet. Refreshable haptic displays that can interact with computers can be used to access such information tactually. Main focus of this study was the development of specialized computer applications allowing users to actively compensate for the inherent issues of haptics when exploring visual diagrams as compared to vision, which we hypothesized, would improve the usability of such devices. An intuitive zooming algorithm capable of automatically detecting significant different zoom levels, providing auditory feedback, preventing cropping of information and preventing zooming in on areas where no features were present was developed to compensate for the lower spatial resolution of haptics and was found to significantly improve the performance of the participants. Another application allowing the users to perform dynamic simplifications on the diagram to compensate for the serial based nature of processing 2D geometric information was tested and found to significantly improve the performance of the participants. For both applications participants liked the user interface and found it more usable, as expected. In addition, in this study we investigated methods that can be used to effectively present different visual features as well as overlaying features present in the visual diagrams. Three methods using several combinations of tactile and auditory modalities were tested. We found that the performance significantly improves when using the overlapping method using different modalities. For tactile only methods developed for deaf blind individuals, the toggle method was surprisingly preferred as compared to the overlapping method
Transcranial Magnetic Stimulation-coil design with improved focality
Transcranial Magnetic Stimulation (TMS) is a technique for neuromodulation that can be used as a non-invasive therapy for various neurological disorders. In TMS, a time varying magnetic field generated from an electromagnetic coilplaced on the scalp is used to induce an electric field inside the brain. TMS coilgeometry plays an important role in determining the focality and depth of penetration of the induced electric field responsible for stimulation. Clinicians and basic scientists are interested in stimulating a localized area of the brain,while minimizing the stimulation of surrounding neural networks. In this paper, a novel coil has been proposed, namely Quadruple Butterfly Coil (QBC) with an improved focality over the commercial Figure-8 coil. Finite element simulations were conducted with both the QBC and the conventional Figure-8 coil. The two coil’s stimulation profiles were assessed with 50 anatomically realistic MRIderived head models. The coils were positioned on the vertex and the scalp over the dorsolateral prefrontal cortex to stimulate the brain. Computer modeling of the coils has been done to determine the parameters of interest-volume of stimulation, maximum electric field, location of maximum electric field and area of stimulation across all 50 head models for both coils
A cross-sectional look at patient concerns in the first six weeks following primary total knee arthroplasty
<p>Abstract</p> <p>Background</p> <p>To date, no researchers have investigated patient concerns in the first six weeks following primary total knee arthroplasty (TKA). An understanding of patient concerns at a time when physical therapists are involved in the treatment of these patients will aid clinicians in providing patient-centered care. Linking of items to the International Classification of Functioning, Disability and Health (ICF) allows for comparison and sharing of data amongst researchers, as the ICF is the accepted framework for evaluating disability in rehabilitation. The objective of this study was to identify patient concerns in the first six weeks following primary TKA and link these concerns to components of the ICF and map them to commonly used outcome measures.</p> <p>Methods</p> <p>Individual interviews were conducted to identify patient concerns during their recovery following primary TKA. Concerns identified by patients were analysed for content and linked to the components of the ICF using the operational definitions of the ICF components. These concerns were mapped to the WOMAC, KOOS and Oxford Knee Scale.</p> <p>Results</p> <p>Thirty patients (18 female) with an average age (SD) of 68.4 (11.1) years completed the study. Patients identified 32 concerns. Twenty-two percent (n = 7) of the concerns linked to Body Function and Structure, 47% (n = 15) to Activity, 13% (n = 4) to Participation, and 13% (n = 4) to the Environmental Factors component of the ICF. Six percent (n = 2) of the concerns did not link to the ICF. Of the 32 concerns identified by patients 14 mapped to the KOOS, 11 to the WOMAC and 4 to the Oxford Knee Scale.</p> <p>Conclusion</p> <p>Patient concerns linked to four different components of the ICF indicating that patients are involved in or are thinking of multiple aspects of life even in this early phase of recovery. The KOOS was found to be the most appropriate for use based on the patients' perspective. However, less than half of the concerns identified by patients were covered by the KOOS, WOMAC or Oxford Knee Scale indicating that other existing measures that evaluate the concepts identified as important to patients should be considered when evaluating outcomes during this acute phase of recovery following primary TKA.</p
Change in patient concerns following total knee arthroplasty described with the International Classification of Functioning, Disability and Health: a repeated measures design
This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens
Impact of non-brain anatomy and coil orientation on inter- and intra-subject variability in TMS at midline
Objective: To investigate inter-subject variability with respect to cerebrospinal fluid thickness and brain-scalp distance, and to investigate intra-subject variability with different coil orientations.
Methods: Simulations of the induced electric field (E-Field) using a figure-8 coil over the vertex were conducted on 50 unique head models, and varying orientations on 25 models. Metrics exploring stimulation intensity, spread, and localization were used to describe inter-subject variability and effects of non-brain anatomy.
Results: Both brain-scalp distance and CSF thickness were correlated with weaker stimulation intensity, and greater spread. Coil rotations show that for the dorsal portion of the stimulated brain, E-Field intensities are highest when the anterior-posterior axis of the coil is perpendicular to the longitudinal fissure, but highest for the medial portion of the stimulated brain when the coil is oriented parallel to the longitudinal fissure.
Conclusions: Normal anatomical variation in healthy individuals leads to significant differences in the site of TMS, the intensity and the spread. These variables are generally neglected but could explain significant variability in basic and clinical studies.
Significance: This is the first work to show how brain-scalp distance and cerebrospinal fluid thickness influence focality, and to show the disassociation between dorsal and medial TMS
Transcranial Magnetic Stimulation: Design of a Stimulator and a Focused Coil for the Application of Small Animals
Transcranial magnetic stimulation (TMS) is a non-invasive, safe, effective, and food and drug administration approved treatment for major depressive disorder. TMS relies on time-varying magnetic fields to induce an electric field in the brain, resulting in depolarization or hyperpolarization of the neurons. Recently, there has been extensive research to improve the magnetic coil design, effectiveness of TMS treatment, and improvement in the computer modeling of human brains, yet little development is reported on the TMS pulse generators and coil design for small animals. TMS pulse generators, or stimulators, are the circuits which provides pulse current to drive the inductive coils (TMS coils), used to generate time-varying magnetic fields. Commercial TMS stimulators are expensive and have limitations of using standard and non-customizable coils. These stimulators do not support small inductive loads, which require high-current capabilities. Furthermore, the commercial animal coil stimulates the entire body of a mouse, as they are designed for large animals. In this paper, the authors present the design of a small sized TMS stimulator and a focused coil for the application on small animals such as mice. The proposed TMS stimulator will have the potential of handling small inductive loads enabling stimulation of specific regions within the mouse brain
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