Virtual reality-based cognitive training for drug abusers: A randomised controlled trial.

PubMed

Man, David W K

2018-05-08

Non-pharmacological means are being developed to enhance cognitive abilities in drug abusers. This study evaluated virtual reality (VR) as an intervention tool for enhancing cognitive and vocational outcomes in 90 young ketamine users (KU) randomly assigned to a treatment group (virtual reality group, VRG; tutor-administered group, TAG) or wait-listed control group (CG). Two training programmes with similar content but different delivery modes (VR-based and manual-based) were applied using a virtual boutique as a training scenario. Outcome assessments comprised the Digit Vigilance Test, Rivermead Behavioural Memory Test, Wisconsin Cart Sorting Test, work-site test and self-efficacy pre- and post-test and during 3- and 6-month follow-ups. The VRG exhibited significant improvements in attention and improvements in memory that were maintained after 3 months. Both the VRG and TAG exhibited significantly improved vocational skills after training which were maintained during follow-up, and improved self-efficacy. VR-based cognitive training might target cognitive problems in KU.

Detecting navigational deficits in cognitive aging and Alzheimer disease using virtual reality.

PubMed

Cushman, Laura A; Stein, Karen; Duffy, Charles J

2008-09-16

Older adults get lost, in many cases because of recognized or incipient Alzheimer disease (AD). In either case, getting lost can be a threat to individual and public safety, as well as to personal autonomy and quality of life. Here we compare our previously described real-world navigation test with a virtual reality (VR) version simulating the same navigational environment. Quantifying real-world navigational performance is difficult and time-consuming. VR testing is a promising alternative, but it has not been compared with closely corresponding real-world testing in aging and AD. We have studied navigation using both real-world and virtual environments in the same subjects: young normal controls (YNCs, n = 35), older normal controls (ONCs, n = 26), patients with mild cognitive impairment (MCI, n = 12), and patients with early AD (EAD, n = 14). We found close correlations between real-world and virtual navigational deficits that increased across groups from YNC to ONC, to MCI, and to EAD. Analyses of subtest performance showed similar profiles of impairment in real-world and virtual testing in all four subject groups. The ONC, MCI, and EAD subjects all showed greatest difficulty in self-orientation and scene localization tests. MCI and EAD patients also showed impaired verbal recall about both test environments. Virtual environment testing provides a valid assessment of navigational skills. Aging and Alzheimer disease (AD) share the same patterns of difficulty in associating visual scenes and locations, which is complicated in AD by the accompanying loss of verbally mediated navigational capacities. We conclude that virtual navigation testing reveals deficits in aging and AD that are associated with potentially grave risks to our patients and the community.

Is physiotherapy integrated virtual walking effective on pain, function, and kinesiophobia in patients with non-specific low-back pain? Randomised controlled trial.

PubMed

Yilmaz Yelvar, Gul Deniz; Çırak, Yasemin; Dalkılınç, Murat; Parlak Demir, Yasemin; Guner, Zeynep; Boydak, Ayşenur

2017-02-01

According to literature, virtual reality was found to reduce pain and kinesiophobia in patients with chronic pain. The purpose of the study was to investigate short-term effect of the virtual reality on pain, function, and kinesiophobia in patients with subacute and chronic non-specific low-back pain METHODS: This randomised controlled study in which 44 patients were randomly assigned to the traditional physiotherapy (control group, 22 subjects) or virtual walking integrated physiotherapy (experimental group, 22 subjects). Before and after treatment, Visual Analog Scale (VAS), TAMPA Kinesiophobia Scale (TKS), Oswestry Disability Index (ODI), Nottingham Health Profile (NHP), Timed-up and go Test (TUG), 6-Minute Walk Test (6MWT), and Single-Leg Balance Test were assessed. The interaction effect between group and time was assessed by using repeated-measures analysis of covariance. After treatment, both groups showed improvement in all parameters. However, VAS, TKS, TUG, and 6MWT scores showed significant differences in favor of the experimental group. Virtual walking integrated physiotherapy reduces pain and kinesiophobia, and improved function in patients with subacute and chronic non-specific low-back pain in short term.

Virtual reality stimuli for force platform posturography.

PubMed

Tossavainen, Timo; Juhola, Martti; Ilmari, Pyykö; Aalto, Heikki; Toppila, Esko

2002-01-01

People relying much on vision in the control of posture are known to have an elevated risk of falling. Dependence on visual control is an important parameter in the diagnosis of balance disorders. We have previously shown that virtual reality methods can be used to produce visual stimuli that affect balance, but suitable stimuli need to be found. In this study the effect of six different virtual reality stimuli on the balance of 22 healthy test subjects was evaluated using force platform posturography. According to the tests two of the stimuli have a significant effect on balance.

Effect of virtual reality-based rehabilitation on upper-extremity function in patients with brain tumor: controlled trial.

PubMed

Yoon, Jisun; Chun, Min Ho; Lee, Sook Joung; Kim, Bo Ryun

2015-06-01

The aim of this study was to evaluate the benefit of virtual reality-based rehabilitation on upper-extremity function in patients with brain tumor. Patients with upper-extremity dysfunction were divided into age-matched and tumor type-matched two groups. The intervention group performed the virtual reality program 30 mins per session for 9 sessions and conventional occupational therapy 30 mins per session for 6 sessions for 3 wks, whereas the control group received conventional occupational therapy alone 30 mins per session for 15 sessions for 3 wks. The Box and Block test, the Manual Function test, and the Fugl-Meyer scale were used to evaluate upper-extremity function. The Korean version of the Modified Barthel Index was used to assess activities of daily living. Forty patients completed the study (20 for each group). Each group exhibited significant posttreatment improvements in the Box and Block test, Manual Function test, Fugl-Meyer scale, and Korean version of the Modified Barthel Index scores. The Box and Block test, the Fugl-Meyer scale, and the Manual Function test showed greater improvements in shoulder/elbow/forearm function in the intervention group and hand function in the control group. Virtual reality-based rehabilitation combined with conventional occupational therapy may be more effective than conventional occupational therapy, especially for proximal upper-extremity function in patients with brain tumor. Further studies considering hand function, such as use of virtual reality programs that targeting hand use, are required.

Virtual reality in the treatment of persecutory delusions: randomised controlled experimental study testing how to reduce delusional conviction.

PubMed

Freeman, Daniel; Bradley, Jonathan; Antley, Angus; Bourke, Emilie; DeWeever, Natalie; Evans, Nicole; Černis, Emma; Sheaves, Bryony; Waite, Felicity; Dunn, Graham; Slater, Mel; Clark, David M

2016-07-01

Persecutory delusions may be unfounded threat beliefs maintained by safety-seeking behaviours that prevent disconfirmatory evidence being successfully processed. Use of virtual reality could facilitate new learning. To test the hypothesis that enabling patients to test the threat predictions of persecutory delusions in virtual reality social environments with the dropping of safety-seeking behaviours (virtual reality cognitive therapy) would lead to greater delusion reduction than exposure alone (virtual reality exposure). Conviction in delusions and distress in a real-world situation were assessed in 30 patients with persecutory delusions. Patients were then randomised to virtual reality cognitive therapy or virtual reality exposure, both with 30 min in graded virtual reality social environments. Delusion conviction and real-world distress were then reassessed. In comparison with exposure, virtual reality cognitive therapy led to large reductions in delusional conviction (reduction 22.0%, P = 0.024, Cohen's d = 1.3) and real-world distress (reduction 19.6%, P = 0.020, Cohen's d = 0.8). Cognitive therapy using virtual reality could prove highly effective in treating delusions. © The Royal College of Psychiatrists 2016.

Virtual reality in the treatment of persecutory delusions: randomised controlled experimental study testing how to reduce delusional conviction

PubMed Central

Freeman, Daniel; Bradley, Jonathan; Antley, Angus; Bourke, Emilie; DeWeever, Natalie; Evans, Nicole; Černis, Emma; Sheaves, Bryony; Waite, Felicity; Dunn, Graham; Slater, Mel; Clark, David M.

2016-01-01

Background Persecutory delusions may be unfounded threat beliefs maintained by safety-seeking behaviours that prevent disconfirmatory evidence being successfully processed. Use of virtual reality could facilitate new learning. Aims To test the hypothesis that enabling patients to test the threat predictions of persecutory delusions in virtual reality social environments with the dropping of safety-seeking behaviours (virtual reality cognitive therapy) would lead to greater delusion reduction than exposure alone (virtual reality exposure). Method Conviction in delusions and distress in a real-world situation were assessed in 30 patients with persecutory delusions. Patients were then randomised to virtual reality cognitive therapy or virtual reality exposure, both with 30 min in graded virtual reality social environments. Delusion conviction and real-world distress were then reassessed. Results In comparison with exposure, virtual reality cognitive therapy led to large reductions in delusional conviction (reduction 22.0%, P = 0.024, Cohen's d = 1.3) and real-world distress (reduction 19.6%, P = 0.020, Cohen's d = 0.8). Conclusion Cognitive therapy using virtual reality could prove highly effective in treating delusions. PMID:27151071

The design and application of virtual ion meter based on LABVIEW 8.0.

PubMed

Meng, Hu; Li, Jiangyuan; Tang, Yonghuai

2009-08-01

The virtual ion meter is developed based on LABVIEW 8.0 by homemade adjusting circuit, data acquisition (DAQ) board, and computer. This note provides details of the structure of testing system and flow chart of DAQ program. This virtual instrument system is applied to multitask testing such as determining rate constant of second-order reaction by pX, pX potentiometric titration, determining oscillating reaction by potential, etc. The result of application indicates that this test system not only has function of real-time data acquiring, displaying, storage, but also realizes remote monitoring and controlling test-control spots through internet, automatic analyzing and processing of data, reporting of result according to the different testing task; moreover, the veracity and repeatability of data processing result are higher than the results of manual data processing.

Stereopsis, Visuospatial Ability, and Virtual Reality in Anatomy Learning

PubMed Central

Vorstenbosch, Marc; Kooloos, Jan

2017-01-01

A new wave of virtual reality headsets has become available. A potential benefit for the study of human anatomy is the reintroduction of stereopsis and absolute size. We report a randomized controlled trial to assess the contribution of stereopsis to anatomy learning, for students of different visuospatial ability. Sixty-three participants engaged in a one-hour session including a study phase and posttest. One group studied 3D models of the anatomy of the deep neck in full stereoptic virtual reality; one group studied those structures in virtual reality without stereoptic depth. The control group experienced an unrelated virtual reality environment. A post hoc questionnaire explored cognitive load and problem solving strategies of the participants. We found no effect of condition on learning. Visuospatial ability however did impact correct answers at F(1) = 5.63 and p = .02. No evidence was found for an impact of cognitive load on performance. Possibly, participants were able to solve the posttest items based on visuospatial information contained in the test items themselves. Additionally, the virtual anatomy may have been complex enough to discourage memory based strategies. It is important to control the amount of visuospatial information present in test items. PMID:28656109

Stereopsis, Visuospatial Ability, and Virtual Reality in Anatomy Learning.

PubMed

Luursema, Jan-Maarten; Vorstenbosch, Marc; Kooloos, Jan

2017-01-01

A new wave of virtual reality headsets has become available. A potential benefit for the study of human anatomy is the reintroduction of stereopsis and absolute size. We report a randomized controlled trial to assess the contribution of stereopsis to anatomy learning, for students of different visuospatial ability. Sixty-three participants engaged in a one-hour session including a study phase and posttest. One group studied 3D models of the anatomy of the deep neck in full stereoptic virtual reality; one group studied those structures in virtual reality without stereoptic depth. The control group experienced an unrelated virtual reality environment. A post hoc questionnaire explored cognitive load and problem solving strategies of the participants. We found no effect of condition on learning. Visuospatial ability however did impact correct answers at F (1) = 5.63 and p = .02. No evidence was found for an impact of cognitive load on performance. Possibly, participants were able to solve the posttest items based on visuospatial information contained in the test items themselves. Additionally, the virtual anatomy may have been complex enough to discourage memory based strategies. It is important to control the amount of visuospatial information present in test items.

Quality of Service Control Based on Virtual Private Network Services in a Wide Area Gigabit Ethernet Optical Test Bed

NASA Astrophysics Data System (ADS)

Rea, Luca; Pompei, Sergio; Valenti, Alessandro; Matera, Francesco; Zema, Cristiano; Settembre, Marina

We report an experimental investigation about the Virtual Private LAN Service technique to guarantee the quality of service in the metro/core network and also in the presence of access bandwidth bottleneck. We also show how the virtual private network can be set up for answering to a user request in a very fast way. The tests were performed in a GMPLS test bed with GbE core routers linked with long (tens of kilometers) GbE G.652 fiber links.

An investigation of the efficacy of collaborative virtual reality systems for moderated remote usability testing.

PubMed

Chalil Madathil, Kapil; Greenstein, Joel S

2017-11-01

Collaborative virtual reality-based systems have integrated high fidelity voice-based communication, immersive audio and screen-sharing tools into virtual environments. Such three-dimensional collaborative virtual environments can mirror the collaboration among usability test participants and facilitators when they are physically collocated, potentially enabling moderated usability tests to be conducted effectively when the facilitator and participant are located in different places. We developed a virtual collaborative three-dimensional remote moderated usability testing laboratory and employed it in a controlled study to evaluate the effectiveness of moderated usability testing in a collaborative virtual reality-based environment with two other moderated usability testing methods: the traditional lab approach and Cisco WebEx, a web-based conferencing and screen sharing approach. Using a mixed methods experimental design, 36 test participants and 12 test facilitators were asked to complete representative tasks on a simulated online shopping website. The dependent variables included the time taken to complete the tasks; the usability defects identified and their severity; and the subjective ratings on the workload index, presence and satisfaction questionnaires. Remote moderated usability testing methodology using a collaborative virtual reality system performed similarly in terms of the total number of defects identified, the number of high severity defects identified and the time taken to complete the tasks with the other two methodologies. The overall workload experienced by the test participants and facilitators was the least with the traditional lab condition. No significant differences were identified for the workload experienced with the virtual reality and the WebEx conditions. However, test participants experienced greater involvement and a more immersive experience in the virtual environment than in the WebEx condition. The ratings for the virtual environment condition were not significantly different from those for the traditional lab condition. The results of this study suggest that participants were productive and enjoyed the virtual lab condition, indicating the potential of a virtual world based approach as an alternative to conventional approaches for synchronous usability testing. Copyright © 2017 Elsevier Ltd. All rights reserved.

A Virtual Information-Action Workspace for Command and Control

NASA Astrophysics Data System (ADS)

Lintern, Gavan; Naikar, Neelam

2002-10-01

Information overload has become a critical challenge within military Command and Control. However, the problem is not so much one of too much information but of abundant information that is poorly organized and poorly represented. In addition, the capabilities to test the effects of decisions before they are implemented and to monitor the progress of events after a decision is implemented are primitive. A virtual information-action workspace could be designed to resolve these issues. The design of such a space would require a detailed understanding of the specific information needed to support decision making in Command and Control. That information can be obtained with the use of knowledge acquisition and knowledge representation tools from the field of applied cognitive psychology. In addition, it will be necessary to integrate forms for perception and action into a virtual space that will support access to the information and that will provide means for testing and implementing decisions. This paper presents a rationale for a virtual information-action workspace and outlines an approach to its design.

The effect of virtual reality training on unilateral spatial neglect in stroke patients.

PubMed

Kim, Yong Mi; Chun, Min Ho; Yun, Gi Jeong; Song, Young Jin; Young, Han Eun

2011-06-01

To investigate the effect of virtual reality training on unilateral spatial neglect in stroke patients. Twenty-four stroke patients (14 males and 10 females, mean age=64.7) who had unilateral spatial neglect as a result of right hemisphere stroke were recruited. All patients were randomly assigned to either the virtual reality (VR) group (n=12) or the control group (n=12). The VR group received VR training, which stimulated the left side of their bodies. The control group received conventional neglect therapy such as visual scanning training. Both groups received therapy for 30 minutes a day, five days per week for three weeks. Outcome measurements included star cancellation test, line bisection test, Catherine Bergego scale (CBS), and the Korean version of modified Barthel index (K-MBI). These measurements were taken before and after treatment. There were no significant differences in the baseline characteristics and initial values between the two groups. The changes in star cancellation test results and CBS in the VR group were significantly higher than those of the control group after treatment. The changes in line bisection test score and the K-MBI in the VR group were not statistically significant. This study suggests that virtual reality training may be a beneficial therapeutic technique on unilateral spatial neglect in stroke patients.

Using virtual reality to distinguish subjects with multiple- but not single-domain amnestic mild cognitive impairment from normal elderly subjects.

PubMed

Mohammadi, Alireza; Kargar, Mahmoud; Hesami, Ehsan

2018-03-01

Spatial disorientation is a hallmark of amnestic mild cognitive impairment (aMCI) and Alzheimer's disease. Our aim was to use virtual reality to determine the allocentric and egocentric memory deficits of subjects with single-domain aMCI (aMCIsd) and multiple-domain aMCI (aMCImd). For this purpose, we introduced an advanced virtual reality navigation task (VRNT) to distinguish these deficits in mild Alzheimer's disease (miAD), aMCIsd, and aMCImd. The VRNT performance of 110 subjects, including 20 with miAD, 30 with pure aMCIsd, 30 with pure aMCImd, and 30 cognitively normal controls was compared. Our newly developed VRNT consists of a virtual neighbourhood (allocentric memory) and virtual maze (egocentric memory). Verbal and visuospatial memory impairments were also examined with Rey Auditory-Verbal Learning Test and Rey-Osterrieth Complex Figure Test, respectively. We found that miAD and aMCImd subjects were impaired in both allocentric and egocentric memory, but aMCIsd subjects performed similarly to the normal controls on both tasks. The miAD, aMCImd, and aMCIsd subjects performed worse on finding the target or required more time in the virtual environment than the aMCImd, aMCIsd, and normal controls, respectively. Our findings indicated the aMCImd and miAD subjects, as well as the aMCIsd subjects, were more impaired in egocentric orientation than allocentric orientation. We concluded that VRNT can distinguish aMCImd subjects, but not aMCIsd subjects, from normal elderly subjects. The VRNT, along with the Rey Auditory-Verbal Learning Test and Rey-Osterrieth Complex Figure Test, can be used as a valid diagnostic tool for properly distinguishing different forms of aMCI. © 2018 Japanese Psychogeriatric Society.

Cognitive training on stroke patients via virtual reality-based serious games.

PubMed

Gamito, Pedro; Oliveira, Jorge; Coelho, Carla; Morais, Diogo; Lopes, Paulo; Pacheco, José; Brito, Rodrigo; Soares, Fabio; Santos, Nuno; Barata, Ana Filipa

2017-02-01

Use of virtual reality environments in cognitive rehabilitation offers cost benefits and other advantages. In order to test the effectiveness of a virtual reality application for neuropsychological rehabilitation, a cognitive training program using virtual reality was applied to stroke patients. A virtual reality-based serious games application for cognitive training was developed, with attention and memory tasks consisting of daily life activities. Twenty stroke patients were randomly assigned to two conditions: exposure to the intervention, and waiting list control. The results showed significant improvements in attention and memory functions in the intervention group, but not in the controls. Overall findings provide further support for the use of VR cognitive training applications in neuropsychological rehabilitation. Implications for Rehabilitation Improvements in memory and attention functions following a virtual reality-based serious games intervention. Training of daily-life activities using a virtual reality application. Accessibility to training contents.

Heading assessment by "tunnel vision" patients and control subjects standing or walking in a virtual reality environment.

PubMed

Apfelbaum, Henry; Pelah, Adar; Peli, Eli

2007-01-01

Virtual reality locomotion simulators are a promising tool for evaluating the effectiveness of vision aids to mobility for people with low vision. This study examined two factors to gain insight into the verisimilitude requirements of the test environment: the effects of treadmill walking and the suitability of using controls as surrogate patients. Ten "tunnel vision" patients with retinitis pigmentosa (RP) were tasked with identifying which side of a clearly visible obstacle their heading through the virtual environment would lead them, and were scored both on accuracy and on their distance from the obstacle when they responded. They were tested both while walking on a treadmill and while standing, as they viewed a scene representing progress through a shopping mall. Control subjects, each wearing a head-mounted field restriction to simulate the vision of a paired patient, were also tested. At wide angles of approach, controls and patients performed with a comparably high degree of accuracy, and made their choices at comparable distances from the obstacle. At narrow angles of approach, patients' accuracy increased when walking, while controls' accuracy decreased. When walking, both patients and controls delayed their decisions until closer to the obstacle. We conclude that a head-mounted field restriction is not sufficient for simulating tunnel vision, but that the improved performance observed for walking compared to standing suggests that a walking interface (such as a treadmill) may be essential for eliciting natural perceptually-guided behavior in virtual reality locomotion simulators.

Using Virtual Pets to Promote Physical Activity in Children: An Application of the Youth Physical Activity Promotion Model.

PubMed

Ahn, Sun Joo Grace; Johnsen, Kyle; Robertson, Tom; Moore, James; Brown, Scott; Marable, Amanda; Basu, Aryabrata

2015-01-01

A virtual pet was developed based on the framework of the youth physical activity promotion model and tested as a vehicle for promoting physical activity in children. Children in the treatment group interacted with the virtual pet for three days, setting physical activity goals and teaching tricks to the virtual pet when their goals were met. The virtual pet became more fit and learned more sophisticated tricks as the children achieved activity goals. Children in the control group interacted with a computer system presenting equivalent features but without the virtual pet. Physical activity and goal attainment were evaluated using activity monitors. Results indicated that children in the treatment group engaged in 1.09 more hours of daily physical activity (156% more) than did those in the control group. Physical activity self-efficacy and beliefs served as mediators driving this increase in activity. Children that interacted with the virtual pet also expressed higher intentions than children in the control group to continue physical activity in the future. Theoretical and practical potentials of using a virtual pet to systematically promote physical activity in children are discussed.

Virtual Reality Exposure Training for Musicians: Its Effect on Performance Anxiety and Quality.

PubMed

Bissonnette, Josiane; Dubé, Francis; Provencher, Martin D; Moreno Sala, Maria T

2015-09-01

Music performance anxiety affects numerous musicians, with many of them reporting impairment of performance due to this problem. This exploratory study investigated the effects of virtual reality exposure training on students with music performance anxiety. Seventeen music students were randomly assigned to a control group (n=8) or a virtual training group (n=9). Participants were asked to play a musical piece by memory in two separate recitals within a 3-week interval. Anxiety was then measured with the Personal Report of Confidence as a Performer Scale and the S-Anxiety scale from the State-Trait Anxiety Inventory (STAI-Y). Between pre- and post-tests, the virtual training group took part in virtual reality exposure training consisting of six 1-hour long sessions of virtual exposure. The results indicate a significant decrease in performance anxiety for musicians in the treatment group for those with a high level of state anxiety, for those with a high level of trait anxiety, for women, and for musicians with high immersive tendencies. Finally, between the pre- and post-tests, we observed a significant increase in performance quality for the experimental group, but not for the control group.

Effects of 3D virtual haptics force feedback on brand personality perception: the mediating role of physical presence in advergames.

PubMed

Jin, Seung-A Annie

2010-06-01

This study gauged the effects of force feedback in the Novint Falcon haptics system on the sensory and cognitive dimensions of a virtual test-driving experience. First, in order to explore the effects of tactile stimuli with force feedback on users' sensory experience, feelings of physical presence (the extent to which virtual physical objects are experienced as actual physical objects) were measured after participants used the haptics interface. Second, to evaluate the effects of force feedback on the cognitive dimension of consumers' virtual experience, this study investigated brand personality perception. The experiment utilized the Novint Falcon haptics controller to induce immersive virtual test-driving through tactile stimuli. The author designed a two-group (haptics stimuli with force feedback versus no force feedback) comparison experiment (N = 238) by manipulating the level of force feedback. Users in the force feedback condition were exposed to tactile stimuli involving various force feedback effects (e.g., terrain effects, acceleration, and lateral forces) while test-driving a rally car. In contrast, users in the control condition test-drove the rally car using the Novint Falcon but were not given any force feedback. Results of ANOVAs indicated that (a) users exposed to force feedback felt stronger physical presence than those in the no force feedback condition, and (b) users exposed to haptics stimuli with force feedback perceived the brand personality of the car to be more rugged than those in the control condition. Managerial implications of the study for product trial in the business world are discussed.

Technology for performing ocular self-examination: comparison between printed and virtual booklets.

PubMed

Nascimento, Jennara Candido; Lima, Maria Alzete; Barros, Lívia Moreira; Galindo Neto, Nelson Miguel; Pagliuca, Lorita Marlena Freitag; Caetano, Joselany Áfio

2018-01-01

Comparing the results of the ocular self-examination performed with the aid of printed and virtual versions of an educational booklet. A quasi-experimental study carried out in a state (public) school of a capital in northeast Brazil, with 100 students equally divided into control and intervention groups according to age, gender, schooling and economic status. Pearson's Chi-square test and Fisher's exact test were applied with a significance level of 5%. The results of the self-examination obtained by the virtual and printed booklets were statistically similar, except for the item 'Alterations of the pupillary reflex', in which the virtual booklet was more effective for its identification (p=0.049). The printed and virtual versions of the ocular educational booklet have similar efficacy for performing ocular self-examination.

Demonstration of Supervisory Control and Data Acquisition (SCADA) Virtualization Capability in the US Army Research Laboratory (ARL)/Sustaining Base Network Assurance Branch (SBNAB) US Army Cyber Analytics Laboratory (ACAL) SCADA Hardware Testbed

DTIC Science & Technology

2015-05-01

application ,1 while the simulated PLC software is the open source ModbusPal Java application . When queried using the Modbus TCP protocol, ModbusPal reports...and programmable logic controller ( PLC ) components. The HMI and PLC components were instantiated with software and installed in multiple virtual...creating and capturing HMI– PLC network traffic over a 24-h period in the virtualized network and inspect the packets for errors.  Test the

The Effect of Virtual Reality Training on Unilateral Spatial Neglect in Stroke Patients

PubMed Central

Kim, Yong Mi; Yun, Gi Jeong; Song, Young Jin; Young, Han Eun

2011-01-01

Objective To investigate the effect of virtual reality training on unilateral spatial neglect in stroke patients. Method Twenty-four stroke patients (14 males and 10 females, mean age=64.7) who had unilateral spatial neglect as a result of right hemisphere stroke were recruited. All patients were randomly assigned to either the virtual reality (VR) group (n=12) or the control group (n=12). The VR group received VR training, which stimulated the left side of their bodies. The control group received conventional neglect therapy such as visual scanning training. Both groups received therapy for 30 minutes a day, five days per week for three weeks. Outcome measurements included star cancellation test, line bisection test, Catherine Bergego scale (CBS), and the Korean version of modified Barthel index (K-MBI). These measurements were taken before and after treatment. Results There were no significant differences in the baseline characteristics and initial values between the two groups. The changes in star cancellation test results and CBS in the VR group were significantly higher than those of the control group after treatment. The changes in line bisection test score and the K-MBI in the VR group were not statistically significant. Conclusion This study suggests that virtual reality training may be a beneficial therapeutic technique on unilateral spatial neglect in stroke patients. PMID:22506138

Grasping trajectories in a virtual environment adhere to Weber's law.

PubMed

Ozana, Aviad; Berman, Sigal; Ganel, Tzvi

2018-06-01

Virtual-reality and telerobotic devices simulate local motor control of virtual objects within computerized environments. Here, we explored grasping kinematics within a virtual environment and tested whether, as in normal 3D grasping, trajectories in the virtual environment are performed analytically, violating Weber's law with respect to object's size. Participants were asked to grasp a series of 2D objects using a haptic system, which projected their movements to a virtual space presented on a computer screen. The apparatus also provided object-specific haptic information upon "touching" the edges of the virtual targets. The results showed that grasping movements performed within the virtual environment did not produce the typical analytical trajectory pattern obtained during 3D grasping. Unlike as in 3D grasping, grasping trajectories in the virtual environment adhered to Weber's law, which indicates relative resolution in size processing. In addition, the trajectory patterns differed from typical trajectories obtained during 3D grasping, with longer times to complete the movement, and with maximum grip apertures appearing relatively early in the movement. The results suggest that grasping movements within a virtual environment could differ from those performed in real space, and are subjected to irrelevant effects of perceptual information. Such atypical pattern of visuomotor control may be mediated by the lack of complete transparency between the interface and the virtual environment in terms of the provided visual and haptic feedback. Possible implications of the findings to movement control within robotic and virtual environments are further discussed.

A standardized set of 3-D objects for virtual reality research and applications.

PubMed

Peeters, David

2018-06-01

The use of immersive virtual reality as a research tool is rapidly increasing in numerous scientific disciplines. By combining ecological validity with strict experimental control, immersive virtual reality provides the potential to develop and test scientific theories in rich environments that closely resemble everyday settings. This article introduces the first standardized database of colored three-dimensional (3-D) objects that can be used in virtual reality and augmented reality research and applications. The 147 objects have been normed for name agreement, image agreement, familiarity, visual complexity, and corresponding lexical characteristics of the modal object names. The availability of standardized 3-D objects for virtual reality research is important, because reaching valid theoretical conclusions hinges critically on the use of well-controlled experimental stimuli. Sharing standardized 3-D objects across different virtual reality labs will allow for science to move forward more quickly.

Inducing physiological stress recovery with sounds of nature in a virtual reality forest--results from a pilot study.

PubMed

Annerstedt, Matilda; Jönsson, Peter; Wallergård, Mattias; Johansson, Gerd; Karlson, Björn; Grahn, Patrik; Hansen, Ase Marie; Währborg, Peter

2013-06-13

Experimental research on stress recovery in natural environments is limited, as is study of the effect of sounds of nature. After inducing stress by means of a virtual stress test, we explored physiological recovery in two different virtual natural environments (with and without exposure to sounds of nature) and in one control condition. Cardiovascular data and saliva cortisol were collected. Repeated ANOVA measurements indicated parasympathetic activation in the group subjected to sounds of nature in a virtual natural environment, suggesting enhanced stress recovery may occur in such surroundings. The group that recovered in virtual nature without sound and the control group displayed no particular autonomic activation or deactivation. The results demonstrate a potential mechanistic link between nature, the sounds of nature, and stress recovery, and suggest the potential importance of virtual reality as a tool in this research field. Copyright © 2013 Elsevier Inc. All rights reserved.

Improving students’ creativity using cooperative learning with virtual media on static fluida concept

NASA Astrophysics Data System (ADS)

Gunawan; Harjono, A.; Sahidu, H.; Nisrina

2018-04-01

Creativity is an important component of global competition in the 21st century. Therefore, learning innovation is needed to make students more creative. This research was conducted to improve students' creativity through cooperative learning using virtual media for the static fluid concept. This study was a quasi-experiment through a pre-test post-test design. The samples were chosen using cluster random sampling technique to obtain two groups, namely experimental group and control group. Data were collected using a creativity test in the form of an essay consisting of verbal and figural tests. The data were analyzed using t-test and N-gain test to determine the improvement of creativity in both groups. The results showed that the improvement of students' creativity in the experimental group was higher than the control group. The difference in the improvement of students’ creativity in both group is significant. Students become more creative especially related to indicators of fluency and elaboration. We conclude that the application of cooperative learning model using virtual media has a positive effect on students’ creativity.

Heading assessment by “tunnel vision” patients and control subjects standing or walking in a virtual reality environment

PubMed Central

APFELBAUM, HENRY; PELAH, ADAR; PELI, ELI

2007-01-01

Virtual reality locomotion simulators are a promising tool for evaluating the effectiveness of vision aids to mobility for people with low vision. This study examined two factors to gain insight into the verisimilitude requirements of the test environment: the effects of treadmill walking and the suitability of using controls as surrogate patients. Ten “tunnel vision” patients with retinitis pigmentosa (RP) were tasked with identifying which side of a clearly visible obstacle their heading through the virtual environment would lead them, and were scored both on accuracy and on their distance from the obstacle when they responded. They were tested both while walking on a treadmill and while standing, as they viewed a scene representing progress through a shopping mall. Control subjects, each wearing a head-mounted field restriction to simulate the vision of a paired patient, were also tested. At wide angles of approach, controls and patients performed with a comparably high degree of accuracy, and made their choices at comparable distances from the obstacle. At narrow angles of approach, patients’ accuracy increased when walking, while controls’ accuracy decreased. When walking, both patients and controls delayed their decisions until closer to the obstacle. We conclude that a head-mounted field restriction is not sufficient for simulating tunnel vision, but that the improved performance observed for walking compared to standing suggests that a walking interface (such as a treadmill) may be essential for eliciting natural perceptually-guided behavior in virtual reality locomotion simulators. PMID:18167511

Determining sensitivity/specificity of virtual reality-based neuropsychological tool for detecting residual abnormalities following sport-related concussion.

PubMed

Teel, Elizabeth; Gay, Michael; Johnson, Brian; Slobounov, Semyon

2016-05-01

Computer-based neuropsychological (NP) evaluation is an effective clinical tool used to assess cognitive function which complements the clinical diagnosis of a concussion. However, some researchers and clinicians argue its lack of ecological validity places limitations on externalizing results to a sensory rich athletic environment. Virtual reality-based NP assessment offers clinical advantages using an immersive environment and evaluating domains not typically assessed by traditional NP assessments. The sensitivity and specificity of detecting lingering cognitive abnormalities was examined on components of a virtual reality-based NP assessment battery to cohort affiliation (concussed vs. controls). Data were retrospectively gathered on 128 controls (no concussion) and 24 concussed college-age athletes on measures of spatial navigation, whole body reaction, attention, and balance in a virtual environment. Concussed athletes were tested within 10 days (M = 8.33, SD = 1.06) of concussion and were clinically asymptomatic at the time of testing. A priori alpha level was set at 0.05 for all tests. Spatial navigation (sensitivity 95.8%/specificity 91.4%, d = 1.89), whole body reaction time (sensitivity 95.2%/specificity 89.1%, d = 1.50) and combined virtual reality modules (sensitivity 95.8%,/specificity 96.1%, d = 3.59) produced high sensitivity/specificity values when determining performance-based variability between groups. Use of a virtual reality-based NP platform can detect lingering cognitive abnormalities resulting from concussion in clinically asymptomatic participants. Virtual reality NP platforms may compliment the traditional concussion assessment battery by providing novel information. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Steering a virtual blowfly: simulation of visual pursuit.

PubMed

Boeddeker, Norbert; Egelhaaf, Martin

2003-09-22

The behavioural repertoire of male flies includes visually guided chasing after moving targets. The visuomotor control system for these pursuits belongs to the fastest found in the animal kingdom. We simulated a virtual fly, to test whether or not experimentally established hypotheses on the underlying control system are sufficient to explain chasing behaviour. Two operating instructions for steering the chasing virtual fly were derived from behavioural experiments: (i) the retinal size of the target controls the fly's forward speed and, thus, indirectly its distance to the target; and (ii) a smooth pursuit system uses the retinal position of the target to regulate the fly's flight direction. Low-pass filters implement neuronal processing time. Treating the virtual fly as a point mass, its kinematics are modelled in consideration of the effects of translatory inertia and air friction. Despite its simplicity, the model shows behaviour similar to that of real flies. Depending on its starting position and orientation as well as on target size and speed, the virtual fly either catches the target or follows it indefinitely without capture. These two behavioural modes of the virtual fly emerge from the control system for flight steering without implementation of an explicit decision maker.

[Evaluation of accuracy of virtual occlusal definition in Angle class I molar relationship].

PubMed

Wu, L; Liu, X J; Li, Z L; Wang, X

2018-02-18

To evaluate the accuracy of virtual occlusal definition in non-Angle class I molar relationship, and to evaluate the clinical feasibility. Twenty pairs of models of orthognathic patients were included in this study. The inclusion criteria were: (1) finished with pre-surgical orthodontic treatment and (2) stable final occlusion. The exclusion criteria were: (1) existence of distorted teeth, (2) needs for segmentation, (3) defect of dentition except for orthodontic extraction ones, and (4) existence of tooth space. The tooth-extracted test group included 10 models with two premolars extracted during preoperative orthodontic treatment. Their molar relationships were not Angle class I relationship. The non-tooth-extracted test group included another 10 models without teeth extracted, therefore their molar relationships were Angle class I. To define the final occlusion in virtual environment, two steps were included: (1) The morphology data of upper and lower dentition were digitalized by surface scanner (Smart Optics/Activity 102; Model-Tray GmbH, Hamburg, Germany); (2) the virtual relationships were defined using 3Shape software. The control standard of final occlusion was manually defined using gypsum models and then digitalized by surface scanner. The final occlusion of test group and control standard were overlapped according to lower dentition morphology. Errors were evaluated by calculating the distance between the corresponding reference points of testing group and control standard locations. The overall errors for upper dentition between test group and control standard location were (0.51±0.18) mm in non-tooth-extracted test group and (0.60±0.36) mm in tooth-extracted test group. The errors were significantly different between these two test groups (P<0.05). However, in both test groups, the errors of each tooth in a single dentition does not differ from one another. There was no significant difference between errors in tooth-extracted test group and 1 mm (P>0.05); and the accuracy of non-tooth-extracted group was significantly smaller than 1 mm (P<0.05). The error of virtual occlusal definition of none class I molar relationship is higher than that of class I relationship, with an accuracy of 1 mm. However, its accuracy is still feasible for clinical application.

Enhancing a Low-Cost Virtual Reality Application through Constructivist Approach: The Case of Spatial Training of Middle Graders

ERIC Educational Resources Information Center

Samsudin, Khairulanuar; Rafi, Ahmad; Mohamad Ali, Ahmad Zamzuri; Abd. Rashid, Nazre

2014-01-01

The aim of this study is to develop and to test a low-cost virtual reality spatial trainer in terms of its effectiveness in spatial training. The researchers adopted three features deriving from the constructivist perspective to guide the design of the trainer, namely interaction, instruction, and support. The no control pre test post test…

Virtual geotechnical laboratory experiments using a simulator

NASA Astrophysics Data System (ADS)

Penumadu, Dayakar; Zhao, Rongda; Frost, David

2000-04-01

The details of a test simulator that provides a realistic environment for performing virtual laboratory experimentals in soil mechanics is presented. A computer program Geo-Sim that can be used to perform virtual experiments, and allow for real-time observations of material response is presented. The results of experiments, for a given set of input parameters, are obtained with the test simulator using well-trained artificial neural-network-based soil models for different soil types and stress paths. Multimedia capabilities are integrated in Geo-Sim, using software that links and controls a laser disc player with a real-time parallel processing ability. During the simulation of a virtual experiment, relevant portions of the video image of a previously recorded test on an actual soil specimen are dispalyed along with the graphical presentation of response from the feedforward ANN model predictions. The pilot simulator developed to date includes all aspects related to performing a triaxial test on cohesionless soil under undrained and drained conditions. The benefits of the test simulator are also presented.

Live Virtual Constructive (LVC): Interface Control Document (ICD) for the LVC Gateway. [Flight Test 3

NASA Technical Reports Server (NTRS)

Jovic, Srba

2015-01-01

This Interface Control Document (ICD) documents and tracks the necessary information required for the Live Virtual and Constructive (LVC) systems components as well as protocols for communicating with them in order to achieve all research objectives captured by the experiment requirements. The purpose of this ICD is to clearly communicate all inputs and outputs from the subsystem components.

Combined virtual and real robotic test-bed for single operator control of multiple robots

NASA Astrophysics Data System (ADS)

Lee, Sam Y.-S.; Hunt, Shawn; Cao, Alex; Pandya, Abhilash

2010-04-01

Teams of heterogeneous robots with different dynamics or capabilities could perform a variety of tasks such as multipoint surveillance, cooperative transport and explorations in hazardous environments. In this study, we work with heterogeneous robots of semi-autonomous ground and aerial robots for contaminant localization. We developed a human interface system which linked every real robot to its virtual counterpart. A novel virtual interface has been integrated with Augmented Reality that can monitor the position and sensory information from video feed of ground and aerial robots in the 3D virtual environment, and improve user situational awareness. An operator can efficiently control the real multi-robots using the Drag-to-Move method on the virtual multi-robots. This enables an operator to control groups of heterogeneous robots in a collaborative way for allowing more contaminant sources to be pursued simultaneously. The advanced feature of the virtual interface system is guarded teleoperation. This can be used to prevent operators from accidently driving multiple robots into walls and other objects. Moreover, the feature of the image guidance and tracking is able to reduce operator workload.

Object Creation and Human Factors Evaluation for Virtual Environments

NASA Technical Reports Server (NTRS)

Lindsey, Patricia F.

1998-01-01

The main objective of this project is to provide test objects for simulated environments utilized by the recently established Army/NASA Virtual Innovations Lab (ANVIL) at Marshall Space Flight Center, Huntsville, Al. The objective of the ANVIL lab is to provide virtual reality (VR) models and environments and to provide visualization and manipulation methods for the purpose of training and testing. Visualization equipment used in the ANVIL lab includes head-mounted and boom-mounted immersive virtual reality display devices. Objects in the environment are manipulated using data glove, hand controller, or mouse. These simulated objects are solid or surfaced three dimensional models. They may be viewed or manipulated from any location within the environment and may be viewed on-screen or via immersive VR. The objects are created using various CAD modeling packages and are converted into the virtual environment using dVise. This enables the object or environment to be viewed from any angle or distance for training or testing purposes.

Traditional microscopy instruction versus process-oriented virtual microscopy instruction: a naturalistic experiment with control group.

PubMed

Helle, Laura; Nivala, Markus; Kronqvist, Pauliina; Gegenfurtner, Andreas; Björk, Pasi; Säljö, Roger

2011-03-30

Virtual microscopy is being introduced in medical education as an approach for learning how to interpret information in microscopic specimens. It is, however, far from evident how to incorporate its use into existing teaching practice. The aim of the study was to explore the consequences of introducing virtual microscopy tasks into an undergraduate pathology course in an attempt to render the instruction more process-oriented. The research questions were: 1) How is virtual microscopy perceived by students? 2) Does work on virtual microscopy tasks contribute to improvement in performance in microscopic pathology in comparison with attending assistant-led demonstrations only? During a one-week period, an experimental group completed three sets of virtual microscopy homework assignments in addition to attending demonstrations. A control group attended the demonstrations only. Performance in microscopic pathology was measured by a pre-test and a post-test. Student perceptions of regular instruction and virtual microscopy were collected one month later by administering the Inventory of Intrinsic Motivation and open-ended questions. The students voiced an appreciation for virtual microscopy for the purposes of the course and for self-study. As for learning gains, the results indicated that learning was speeded up in a subgroup of students consisting of conscientious high achievers. The enriched instruction model may be suited as such for elective courses following the basic course. However, the instructional model needs further development to be suited for basic courses.

Virtual reality job interview training and 6-month employment outcomes for individuals with schizophrenia seeking employment.

PubMed

Smith, Matthew J; Fleming, Michael F; Wright, Michael A; Roberts, Andrea G; Humm, Laura Boteler; Olsen, Dale; Bell, Morris D

2015-08-01

Individuals with schizophrenia have low employment rates and the job interview presents a critical barrier for them to obtain employment. Virtual reality training has demonstrated efficacy at improving interview skills and employment outcomes among multiple clinical populations. However, the effects of this training on individuals with schizophrenia are unknown. This study evaluated the efficacy of virtual reality job interview training (VR-JIT) at improving job interview skills and employment outcomes among individuals with schizophrenia in a small randomized controlled trial (n=21 VR-JIT trainees, n=11 waitlist controls). Trainees completed up to 10h of virtual interviews using VR-JIT, while controls received services as usual. Primary outcome measures included two pre-test and two post-test video-recorded role-play interviews scored by blinded raters with expertise in human resources and self-reported interviewing self-confidence. Six-month follow-up data on employment outcomes were collected. Trainees reported that the intervention was easy-to-use, helpful, and prepared them for future interviews. Trainees demonstrated increased role-play scores between pre-test and post-test while controls did not (p=0.001). After accounting for neurocognition and months since prior employment, trainees had greater odds of receiving a job offer by 6month follow-up compared to controls (OR: 8.73, p=0.04) and more training was associated with fewer weeks until receiving a job offer (r=-0.63, p<0.001). Results suggest that VR-JIT is acceptable to trainees and may be efficacious for improving job interview skills in individuals with schizophrenia. Moreover, trainees had greater odds of receiving a job offer by 6-month follow-up. Future studies could evaluate the effectiveness of VR-JIT within community-based services. Copyright © 2015 Elsevier B.V. All rights reserved.

Extrinsic finger and thumb muscles command a virtual hand to allow individual finger and grasp control.

PubMed

Birdwell, J Alexander; Hargrove, Levi J; Weir, Richard F ff; Kuiken, Todd A

2015-01-01

Fine-wire intramuscular electrodes were used to obtain electromyogram (EMG) signals from six extrinsic hand muscles associated with the thumb, index, and middle fingers. Subjects' EMG activity was used to control a virtual three-degree-of-freedom (DOF) hand as they conformed the hand to a sequence of hand postures testing two controllers: direct EMG control and pattern recognition control. Subjects tested two conditions using each controller: starting the hand from a predefined neutral posture before each new posture and starting the hand from the previous posture in the sequence. Subjects demonstrated their abilities to simultaneously, yet individually, move all three DOFs during the direct EMG control trials; however, results showed subjects did not often utilize this feature. Performance metrics such as failure rate and completion time showed no significant difference between the two controllers.

Can virtual science foster real skills? A study of inquiry skills in a virtual world

NASA Astrophysics Data System (ADS)

Dodds, Heather E.

Online education has grown into a part of the educational market answering the demand for learning at the learner's choice of time and place. Inquiry skills such as observing, questioning, collecting data, and devising fair experiments are an essential element of 21st-century online science coursework. Virtual immersive worlds such as Second Life are being used as new frontiers in science education. There have been few studies looking specifically at science education in virtual worlds that foster inquiry skills. This quantitative quasi-experimental nonrandomized control group pretest and posttest study explored what affect a virtual world experience had on inquiry skills as measured by the TIPS (Test of Integrated Process Skills) and TIPS II (Integrated Process Skills Test II) instruments. Participants between the ages of 18 and 65 were recruited from educator mailing lists and Second Life discussion boards and then sorted into the experimental group, which received instructions to utilize several displays in Mendelian genetics at the Genome Island location within Second Life, or the control group, which received text-based PDF documents of the same genetics course content. All participants, in the form of avatars, were experienced Second Life residents to reduce any novelty effect. This study found a greater increase in inquiry skills in the experimental group interacting using a virtual world to learn science content (0.90 points) than a control group that is presented only with online text-based content (0.87 points). Using a mixed between-within ANOVA (analysis of variance), with an alpha level of 0.05, there was no significant interaction between the control or experimental groups and inquiry skills, F (1, 58) = .783, p = .380, partial eta squared = .013, at the specified .05 alpha level suggesting no significant difference as a result of the virtual world exercise. However, there is not enough evidence to state that there was no effect because there was a greater increase in scores for the group that experienced a virtual world exercise. This study adds to the increasing body of knowledge about virtual worlds and inquiry skills, particularly with adult learners.

A New Approach to Improve Cognition, Muscle Strength, and Postural Balance in Community-Dwelling Elderly with a 3-D Virtual Reality Kayak Program.

PubMed

Park, Junhyuck; Yim, JongEun

2016-01-01

Aging is usually accompanied with deterioration of physical abilities, such as muscular strength, sensory sensitivity, and functional capacity. Recently, intervention methods with virtual reality have been introduced, providing an enjoyable therapy for elderly. The aim of this study was to investigate whether a 3-D virtual reality kayak program could improve the cognitive function, muscle strength, and balance of community-dwelling elderly. Importantly, kayaking involves most of the upper body musculature and needs the balance control. Seventy-two participants were randomly allocated into the kayak program group (n = 36) and the control group (n = 36). The two groups were well matched with respect to general characteristics at baseline. The participants in both groups performed a conventional exercise program for 30 min, and then the 3-D virtual reality kayak program was performed in the kayak program group for 20 min, two times a week for 6 weeks. Cognitive function was measured using the Montreal Cognitive Assessment. Muscle strength was measured using the arm curl and handgrip strength tests. Standing and sitting balance was measured using the Good Balance system. The post-test was performed in the same manner as the pre-test; the overall outcomes such as cognitive function (p < 0.05), muscle strength (p < 0.05), and balance (standing and sitting balance, p < 0.05) were significantly improved in kayak program group compared to the control group. We propose that the 3-D virtual reality kayak program is a promising intervention method for improving the cognitive function, muscle strength, and balance of elderly.

Home-based virtual reality balance training and conventional balance training in Parkinson's disease: A randomized controlled trial.

PubMed

Yang, Wen-Chieh; Wang, Hsing-Kuo; Wu, Ruey-Meei; Lo, Chien-Shun; Lin, Kwan-Hwa

2016-09-01

Virtual reality has the advantage to provide rich sensory feedbacks for training balance function. This study tested if the home-based virtual reality balance training is more effective than the conventional home balance training in improving balance, walking, and quality of life in patients with Parkinson's disease (PD). Twenty-three patients with idiopathic PD were recruited and underwent twelve 50-minute training sessions during the 6-week training period. The experimental group (n = 11) was trained with a custom-made virtual reality balance training system, and the control group (n = 12) was trained by a licensed physical therapist. Outcomes were measured at Week 0 (pretest), Week 6 (posttest), and Week 8 (follow-up). The primary outcome was the Berg Balance Scale. The secondary outcomes included the Dynamic Gait Index, timed Up-and-Go test, Parkinson's Disease Questionnaire, and the motor score of the Unified Parkinson's Disease Rating Scale. The experimental and control groups were comparable at pretest. After training, both groups performed better in the Berg Balance Scale, Dynamic Gait Index, timed Up-and-Go test, and Parkinson's Disease Questionnaire at posttest and follow-up than at pretest. However, no significant differences were found between these two groups at posttest and follow-up. This study did not find any difference between the effects of the home-based virtual reality balance training and conventional home balance training. The two training options were equally effective in improving balance, walking, and quality of life among community-dwelling patients with PD. Copyright © 2015. Published by Elsevier B.V.

VERDEX: A virtual environment demonstrator for remote driving applications

NASA Technical Reports Server (NTRS)

Stone, Robert J.

1991-01-01

One of the key areas of the National Advanced Robotics Centre's enabling technologies research program is that of the human system interface, phase 1 of which started in July 1989 and is currently addressing the potential of virtual environments to permit intuitive and natural interactions between a human operator and a remote robotic vehicle. The aim of the first 12 months of this program (to September, 1990) is to develop a virtual human-interface demonstrator for use later as a test bed for human factors experimentation. This presentation will describe the current state of development of the test bed, and will outline some human factors issues and problems for more general discussion. In brief, the virtual telepresence system for remote driving has been designed to take the following form. The human operator will be provided with a helmet-mounted stereo display assembly, facilities for speech recognition and synthesis (using the Marconi Macrospeak system), and a VPL DataGlove Model 2 unit. The vehicle to be used for the purposes of remote driving is a Cybermotion Navmaster K2A system, which will be equipped with a stereo camera and microphone pair, mounted on a motorized high-speed pan-and-tilt head incorporating a closed-loop laser ranging sensor for camera convergence control (currently under contractual development). It will be possible to relay information to and from the vehicle and sensory system via an umbilical or RF link. The aim is to develop an interactive audio-visual display system capable of presenting combined stereo TV pictures and virtual graphics windows, the latter featuring control representations appropriate for vehicle driving and interaction using a graphical 'hand,' slaved to the flex and tracking sensors of the DataGlove and an additional helmet-mounted Polhemus IsoTrack sensor. Developments planned for the virtual environment test bed include transfer of operator control between remote driving and remote manipulation, dexterous end effector integration, virtual force and tactile sensing (also the focus of a current ARRL contract, initially employing a 14-pneumatic bladder glove attachment), and sensor-driven world modeling for total virtual environment generation and operator-assistance in remote scene interrogation.

Virtual reality for improving balance in patients after stroke: A systematic review and meta-analysis.

PubMed

Li, Zhen; Han, Xiu-Guo; Sheng, Jing; Ma, Shao-Jun

2016-05-01

To evaluate the effectiveness of virtual reality interventions for improving balance in people after stroke. Systematic review and meta-analysis of randomized controlled trials. Studies were obtained by searching the following databases: MEDLINE, CINAHL, EMBASE, Web of Science and CENTRAL. Two reviewers assessed studies for inclusion, extracted data and assessed trial quality. Sixteen studies involving 428 participants were included. People who received virtual reality interventions showed marked improvements in Berg Balance Scale (mean difference: 1.46, 95% confidence interval: 0.09-2.83, P<0.05, I²=0%) and Timed Up and Go Test (mean difference: -1.62, 95% confidence interval: -3.07- -0.16, P<0.05, I²=24%) compared with controls. This meta-analysis of randomized controlled trials supports the use of virtual reality to improve balance after stroke. © The Author(s) 2015.

Robotic virtual reality simulation plus standard robotic orientation versus standard robotic orientation alone: a randomized controlled trial.

PubMed

Vaccaro, Christine M; Crisp, Catrina C; Fellner, Angela N; Jackson, Christopher; Kleeman, Steven D; Pavelka, James

2013-01-01

The objective of this study was to compare the effect of virtual reality simulation training plus robotic orientation versus robotic orientation alone on performance of surgical tasks using an inanimate model. Surgical resident physicians were enrolled in this assessor-blinded randomized controlled trial. Residents were randomized to receive either (1) robotic virtual reality simulation training plus standard robotic orientation or (2) standard robotic orientation alone. Performance of surgical tasks was assessed at baseline and after the intervention. Nine of 33 modules from the da Vinci Skills Simulator were chosen. Experts in robotic surgery evaluated each resident's videotaped performance of the inanimate model using the Global Rating Scale (GRS) and Objective Structured Assessment of Technical Skills-modified for robotic-assisted surgery (rOSATS). Nine resident physicians were enrolled in the simulation group and 9 in the control group. As a whole, participants improved their total time, time to incision, and suture time from baseline to repeat testing on the inanimate model (P = 0.001, 0.003, <0.001, respectively). Both groups improved their GRS and rOSATS scores significantly (both P < 0.001); however, the GRS overall pass rate was higher in the simulation group compared with the control group (89% vs 44%, P = 0.066). Standard robotic orientation and/or robotic virtual reality simulation improve surgical skills on an inanimate model, although this may be a function of the initial "practice" on the inanimate model and repeat testing of a known task. However, robotic virtual reality simulation training increases GRS pass rates consistent with improved robotic technical skills learned in a virtual reality environment.

The effects of game-based virtual reality movement therapy plus mental practice on upper extremity function in chronic stroke patients with hemiparesis: a randomized controlled trial.

PubMed

Park, Jin-Hyuck; Park, Ji-Hyuk

2016-03-01

[Purpose] The purpose of this study was to investigate the effects of game-based virtual reality movement therapy plus mental practice on upper extremity function in chronic stroke patients with hemiparesis. [Subjects] The subjects were chronic stroke patients with hemiparesis. [Methods] Thirty subjects were randomly assigned to either the control group or experimental group. All subjects received 20 sessions (5 days in a week) of virtual reality movement therapy using the Nintendo Wii. In addition to Wii-based virtual reality movement therapy, experimental group subjects performed mental practice consisting of 5 minutes of relaxation, Wii games imagination, and normalization phases before the beginning of Wii games. To compare the two groups, the upper extremity subtest of the Fugl-Meyer Assessment, Box and Block Test, and quality of movement subscale of the Motor Activity Log were performed. [Results] Both groups showed statistically significant improvement in the Fugl-Meyer Assessment, Box and Block Test, and quality of the movement subscale of Motor Activity Log after the interventions. Also, there were significant differences in the Fugl-Meyer Assessment, Box and Block Test, and quality of movement subscale of the Motor Activity Log between the two groups. [Conclusion] Game-based virtual reality movement therapy alone may be helpful to improve functional recovery of the upper extremity, but the addition of MP produces a lager improvement.

Identifying Anxiety Through Tracked Head Movements in a Virtual Classroom.

PubMed

Won, Andrea Stevenson; Perone, Brian; Friend, Michelle; Bailenson, Jeremy N

2016-06-01

Virtual reality allows the controlled simulation of complex social settings, such as classrooms, and thus provides an opportunity to test a range of theories in the social sciences in a way that is both naturalistic and controlled. Importantly, virtual environments also allow the body movements of participants in the virtual world to be tracked and recorded. In the following article, we discuss how tracked head movements were correlated with participants' reports of anxiety in a simulation of a classroom. Participants who reported a high sense of awareness of and concern about the other virtual people in the room showed different patterns of head movement (more lateral head movement, indicating scanning behavior) from those who reported a low level of concern. We discuss the implications of this research for understanding nonverbal behavior associated with anxiety and for the design of online educational systems.

Virtually Out of This World!

NASA Technical Reports Server (NTRS)

2002-01-01

Ames Research Center granted Reality Capture Technologies (RCT), Inc., a license to further develop NASA's Mars Map software platform. The company incorporated NASA#s innovation into software that uses the Virtual Plant Model (VPM)(TM) to structure, modify, and implement the construction sites of industrial facilities, as well as develop, validate, and train operators on procedures. The VPM orchestrates the exchange of information between engineering, production, and business transaction systems. This enables users to simulate, control, and optimize work processes while increasing the reliability of critical business decisions. Engineers can complete the construction process and test various aspects of it in virtual reality before building the actual structure. With virtual access to and simulation of the construction site, project personnel can manage, access control, and respond to changes on complex constructions more effectively. Engineers can also create operating procedures, training, and documentation. Virtual Plant Model(TM) is a trademark of Reality Capture Technologies, Inc.

Virtual data

NASA Astrophysics Data System (ADS)

Bjorklund, E.

1994-12-01

In the 1970s, when computers were memory limited, operating system designers created the concept of "virtual memory", which gave users the ability to address more memory than physically existed. In the 1990s, many large control systems have the potential of becoming data limited. We propose that many of the principles behind virtual memory systems (working sets, locality, caching and clustering) can also be applied to data-limited systems, creating, in effect, "virtual data systems". At the Los Alamos National Laboratory's Clinton P. Anderson Meson Physics Facility (LAMPF), we have applied these principles to a moderately sized (10 000 data points) data acquisition and control system. To test the principles, we measured the system's performance during tune-up, production, and maintenance periods. In this paper, we present a general discussion of the principles of a virtual data system along with some discussion of our own implementation and the results of our performance measurements.

Web-Based Testing Tools for Electrical Engineering Courses

DTIC Science & Technology

2001-09-01

ideas of distance learning are based on forming “ virtual teams” [2]. Each team is equipped with the same software packages and share information via...using virtual laboratories where they can simulate a laboratory experience in a web-based environment. They can also control laboratory devices over...possible to create a set of virtual laboratories that allow students to interact with the learning material at the same time that the student is

Virtual Satellite

NASA Technical Reports Server (NTRS)

Hammrs, Stephan R.

2008-01-01

Virtual Satellite (VirtualSat) is a computer program that creates an environment that facilitates the development, verification, and validation of flight software for a single spacecraft or for multiple spacecraft flying in formation. In this environment, enhanced functionality and autonomy of navigation, guidance, and control systems of a spacecraft are provided by a virtual satellite that is, a computational model that simulates the dynamic behavior of the spacecraft. Within this environment, it is possible to execute any associated software, the development of which could benefit from knowledge of, and possible interaction (typically, exchange of data) with, the virtual satellite. Examples of associated software include programs for simulating spacecraft power and thermal- management systems. This environment is independent of the flight hardware that will eventually host the flight software, making it possible to develop the software simultaneously with, or even before, the hardware is delivered. Optionally, by use of interfaces included in VirtualSat, hardware can be used instead of simulated. The flight software, coded in the C or C++ programming language, is compilable and loadable into VirtualSat without any special modifications. Thus, VirtualSat can serve as a relatively inexpensive software test-bed for development test, integration, and post-launch maintenance of spacecraft flight software.

Effect of a virtual environment on the development of mathematical skills in children with dyscalculia.

PubMed

de Castro, Marcus Vasconcelos; Bissaco, Márcia Aparecida Silva; Panccioni, Bruno Marques; Rodrigues, Silvia Cristina Martini; Domingues, Andreia Miranda

2014-01-01

In this study, we show the effectiveness of a virtual environment comprising 18 computer games that cover mathematics topics in a playful setting and that can be executed on the Internet with the possibility of player interaction through chat. An arithmetic pre-test contained in the Scholastic Performance Test was administered to 300 children between 7 and 10 years old, including 162 males and 138 females, in the second grade of primary school. Twenty-six children whose scores showed a low level of mathematical knowledge were chosen and randomly divided into the control (CG) and experimental (EG) groups. The EG participated to the virtual environment and the CG participated in reinforcement using traditional teaching methods. Both groups took a post-test in which the Scholastic Performance Test (SPT) was given again. A statistical analysis of the results using the Student's t-test showed a significant learning improvement for the EG and no improvement for the CG (p≤0.05). The virtual environment allows the students to integrate thought, feeling and action, thus motivating the children to learn and contributing to their intellectual development.

Data-based virtual unmodeled dynamics driven multivariable nonlinear adaptive switching control.

PubMed

Chai, Tianyou; Zhang, Yajun; Wang, Hong; Su, Chun-Yi; Sun, Jing

2011-12-01

For a complex industrial system, its multivariable and nonlinear nature generally make it very difficult, if not impossible, to obtain an accurate model, especially when the model structure is unknown. The control of this class of complex systems is difficult to handle by the traditional controller designs around their operating points. This paper, however, explores the concepts of controller-driven model and virtual unmodeled dynamics to propose a new design framework. The design consists of two controllers with distinct functions. First, using input and output data, a self-tuning controller is constructed based on a linear controller-driven model. Then the output signals of the controller-driven model are compared with the true outputs of the system to produce so-called virtual unmodeled dynamics. Based on the compensator of the virtual unmodeled dynamics, the second controller based on a nonlinear controller-driven model is proposed. Those two controllers are integrated by an adaptive switching control algorithm to take advantage of their complementary features: one offers stabilization function and another provides improved performance. The conditions on the stability and convergence of the closed-loop system are analyzed. Both simulation and experimental tests on a heavily coupled nonlinear twin-tank system are carried out to confirm the effectiveness of the proposed method.

The Virtual Tablet: Virtual Reality as a Control System

NASA Technical Reports Server (NTRS)

Chronister, Andrew

2016-01-01

In the field of human-computer interaction, Augmented Reality (AR) and Virtual Reality (VR) have been rapidly growing areas of interest and concerted development effort thanks to both private and public research. At NASA, a number of groups have explored the possibilities afforded by AR and VR technology, among which is the IT Advanced Concepts Lab (ITACL). Within ITACL, the AVR (Augmented/Virtual Reality) Lab focuses on VR technology specifically for its use in command and control. Previous work in the AVR lab includes the Natural User Interface (NUI) project and the Virtual Control Panel (VCP) project, which created virtual three-dimensional interfaces that users could interact with while wearing a VR headset thanks to body- and hand-tracking technology. The Virtual Tablet (VT) project attempts to improve on these previous efforts by incorporating a physical surrogate which is mirrored in the virtual environment, mitigating issues with difficulty of visually determining the interface location and lack of tactile feedback discovered in the development of previous efforts. The physical surrogate takes the form of a handheld sheet of acrylic glass with several infrared-range reflective markers and a sensor package attached. Using the sensor package to track orientation and a motion-capture system to track the marker positions, a model of the surrogate is placed in the virtual environment at a position which corresponds with the real-world location relative to the user's VR Head Mounted Display (HMD). A set of control mechanisms is then projected onto the surface of the surrogate such that to the user, immersed in VR, the control interface appears to be attached to the object they are holding. The VT project was taken from an early stage where the sensor package, motion-capture system, and physical surrogate had been constructed or tested individually but not yet combined or incorporated into the virtual environment. My contribution was to combine the pieces of hardware, write software to incorporate each piece of position or orientation data into a coherent description of the object's location in space, place the virtual analogue accordingly, and project the control interface onto it, resulting in a functioning object which has both a physical and a virtual presence. Additionally, the virtual environment was enhanced with two live video feeds from cameras mounted on the robotic device being used as an example target of the virtual interface. The working VT allows users to naturally interact with a control interface with little to no training and without the issues found in previous efforts.

An enhanced methodology for spacecraft correlation activity using virtual testing tools

NASA Astrophysics Data System (ADS)

Remedia, Marcello; Aglietti, Guglielmo S.; Appolloni, Matteo; Cozzani, Alessandro; Kiley, Andrew

2017-11-01

Test planning and post-test correlation activity have been issues of growing importance in the last few decades and many methodologies have been developed to either quantify or improve the correlation between computational and experimental results. In this article the methodologies established so far are enhanced with the implementation of a recently developed procedure called Virtual Testing. In the context of fixed-base sinusoidal tests (commonly used in the space sector for correlation), there are several factors in the test campaign that affect the behaviour of the satellite and are not normally taken into account when performing analyses: different boundary conditions created by the shaker's own dynamics, non-perfect control system, signal delays etc. All these factors are the core of the Virtual Testing implementation, which will be thoroughly explained in this article and applied to the specific case of Bepi-Colombo spacecraft tested on the ESA QUAD Shaker. Correlation activity will be performed in the various stages of the process, showing important improvements observed after applying the final complete methodology.

Shared virtual environments for telerehabilitation.

PubMed

Popescu, George V; Burdea, Grigore; Boian, Rares

2002-01-01

Current VR telerehabilitation systems use offline remote monitoring from the clinic and patient-therapist videoconferencing. Such "store and forward" and video-based systems cannot implement medical services involving patient therapist direct interaction. Real-time telerehabilitation applications (including remote therapy) can be developed using a shared Virtual Environment (VE) architecture. We developed a two-user shared VE for hand telerehabilitation. Each site has a telerehabilitation workstation with a videocamera and a Rutgers Master II (RMII) force feedback glove. Each user can control a virtual hand and interact hapticly with virtual objects. Simulated physical interactions between therapist and patient are implemented using hand force feedback. The therapist's graphic interface contains several virtual panels, which allow control over the rehabilitation process. These controls start a videoconferencing session, collect patient data, or apply therapy. Several experimental telerehabilitation scenarios were successfully tested on a LAN. A Web-based approach to "real-time" patient telemonitoring--the monitoring portal for hand telerehabilitation--was also developed. The therapist interface is implemented as a Java3D applet that monitors patient hand movement. The monitoring portal gives real-time performance on off-the-shelf desktop workstations.

The effect of virtual reality gaming on dynamic balance in older adults.

PubMed

Rendon, Abel Angel; Lohman, Everett B; Thorpe, Donna; Johnson, Eric G; Medina, Ernie; Bradley, Bruce

2012-07-01

physical therapy interventions that increase functional strength and balance have been shown to reduce falls in older adults. this study compared a virtual reality group (VRG) and a control group (CG). randomised controlled 6-week intervention with pre- and post-test evaluations. outpatient geriatric orthopaedic and balance physical therapy clinic. forty participants were randomised into two groups. the VRG received three different Nintendo® Wii FIT balance interventions three times per week for 6 weeks and the CG received no intervention. compared with the CG, post-intervention measurements showed significant improvements for the VRG in the 8-foot Up & Go test [median decrease of 1.0 versus -0.2 s, (P=0.038) and the Activities-specific Balance Confidence Scale (6.9 versus 1.3%) (P=0.038)]. virtual reality gaming provides clinicians with a useful tool for improving dynamic balance and balance confidence in older adults.

A Virtual Reality avatar interaction (VRai) platform to assess residual executive dysfunction in active military personnel with previous mild traumatic brain injury: proof of concept.

PubMed

Robitaille, Nicolas; Jackson, Philip L; Hébert, Luc J; Mercier, Catherine; Bouyer, Laurent J; Fecteau, Shirley; Richards, Carol L; McFadyen, Bradford J

2017-10-01

This proof of concept study tested the ability of a dual task walking protocol using a recently developed avatar-based virtual reality (VR) platform to detect differences between military personnel post mild traumatic brain injury (mTBI) and healthy controls. The VR platform coordinated motion capture, an interaction and rendering system, and a projection system to present first (participant-controlled) and third person avatars within the context of a specific military patrol scene. A divided attention task was also added. A healthy control group was compared to a group with previous mTBI (both groups comprised of six military personnel) and a repeated measures ANOVA tested for differences between conditions and groups based on recognition errors, walking speed and fluidity and obstacle clearance. The VR platform was well tolerated by both groups. Walking fluidity was degraded for the control group within the more complex navigational dual tasking involving avatars, and appeared greatest in the dual tasking with the interacting avatar. This navigational behaviour was not seen in the mTBI group. The present findings show proof of concept for using avatars, particularly more interactive avatars, to expose differences in executive functioning when applying context-specific protocols (here for the military). Implications for rehabilitation Virtual reality provides a means to control context-specific factors for assessment and intervention. Adding human interaction and agency through avatars increases the ecologic nature of the virtual environment. Avatars in the present application of the Virtual Reality avatar interaction platform appear to provide a better ability to reveal differences between trained, military personal with and without mTBI.

Content and structure of knowledge base used for virtual control of android arm motion in specified environment

NASA Astrophysics Data System (ADS)

Pritykin, F. N.; Nebritov, V. I.

2018-01-01

The paper presents the configuration of knowledge base necessary for intelligent control of android arm mechanism motion with different positions of certain forbidden regions taken into account. The present structure of the knowledge base characterizes the past experience of arm motion synthesis in the vector of velocities with due regard for the known obstacles. This structure also specifies its intrinsic properties. Knowledge base generation is based on the study of the arm mechanism instantaneous states implementations. Computational experiments connected with the virtual control of android arm motion with known forbidden regions using the developed knowledge base are introduced. Using the developed knowledge base to control virtually the arm motion reduces the time of test assignments calculation. The results of the research can be used in developing control systems of autonomous android robots in the known in advance environment.

Improvement in balance using a virtual reality-based stepping exercise: a randomized controlled trial involving individuals with chronic stroke.

PubMed

Lloréns, Roberto; Gil-Gómez, José-Antonio; Alcañiz, Mariano; Colomer, Carolina; Noé, Enrique

2015-03-01

To study the clinical effectiveness and the usability of a virtual reality-based intervention compared with conventional physical therapy in the balance recovery of individuals with chronic stroke. Randomized controlled trial. Outpatient neurorehabilitation unit. A total of 20 individuals with chronic stroke. The intervention consisted of 20 one-hour sessions, five sessions per week. The experimental group combined 30 minutes with the virtual reality-based intervention with 30 minutes of conventional training. The control group underwent one hour conventional therapy. Balance performance was assessed at the beginning and at the end of the trial using the Berg Balance Scale, the balance and gait subscales of the Tinetti Performance-Oriented Mobility Assessment, the Brunel Balance Assessment, and the 10-m Walking Test. Subjective data of the virtual reality-based intervention were collected from the experimental group, with a feedback questionnaire at the end of the trial. The results revealed a significant group-by-time interaction in the scores of the Berg Balance Scale (p < 0.05) and in the 10-m Walking Test (p < 0.05). Post-hoc analyses showed greater improvement in the experimental group: 3.8 ±2.6 vs. 1.8 ±1.4 in the Berg Balance Scale, -1.9 ±1.6 seconds vs. 0.0 ±2.3 seconds in the 10-m Walking Test, and also in the number of participants who increased level in the Brunel Balance Assessment (χ(2) = 2.5, p < 0.01). Virtual reality interventions can be an effective resource to enhance the improvement of balance in individuals with chronic stroke. © The Author(s) 2014.

Controlling Within-Field Sheep Movement Using Virtual Fencing.

PubMed

Marini, Danila; Llewellyn, Rick; Belson, Sue; Lee, Caroline

2018-02-26

Virtual fencing has the potential to greatly improve livestock movement, grazing efficiency, and land management by farmers; however, relatively little work has been done to test the potential of virtual fencing with sheep. Commercial dog training equipment, comprising of a collar and GPS hand-held unit were used to implement a virtual fence in a commercial setting. Six, 5-6 year-old Merino wethers, which were naïve to virtual fencing were GPS tracked for their use of a paddock (80 × 20 m) throughout the experiment. The virtual fence was effective at preventing a small group of sheep from entering the exclusion zone. The probability of a sheep receiving an electrical stimulus following an audio cue was low (19%), and declined over the testing period. It took an average of eight interactions with the fence for an association to be made between the audio and stimulus cue, with all of the animals responding to the audio alone by the third day. Following the removal of the virtual fence, sheep were willing to cross the previous location of the virtual fence after 30 min of being in the paddock. This is an important aspect in the implementation of virtual fencing as a grazing management tool and further enforces that the sheep in this study were able to associate the audio with the virtual fence and not the physical location itself.

Evaluation of navigation interfaces in virtual environments

NASA Astrophysics Data System (ADS)

Mestre, Daniel R.

2014-02-01

When users are immersed in cave-like virtual reality systems, navigational interfaces have to be used when the size of the virtual environment becomes larger than the physical extent of the cave floor. However, using navigation interfaces, physically static users experience self-motion (visually-induced vection). As a consequence, sensorial incoherence between vision (indicating self-motion) and other proprioceptive inputs (indicating immobility) can make them feel dizzy and disoriented. We tested, in two experimental studies, different locomotion interfaces. The objective was twofold: testing spatial learning and cybersickness. In a first experiment, using first-person navigation with a flystick ®, we tested the effect of sensorial aids, a spatialized sound or guiding arrows on the ground, attracting the user toward the goal of the navigation task. Results revealed that sensorial aids tended to impact negatively spatial learning. Moreover, subjects reported significant levels of cybersickness. In a second experiment, we tested whether such negative effects could be due to poorly controlled rotational motion during simulated self-motion. Subjects used a gamepad, in which rotational and translational displacements were independently controlled by two joysticks. Furthermore, we tested first- versus third-person navigation. No significant difference was observed between these two conditions. Overall, cybersickness tended to be lower, as compared to experiment 1, but the difference was not significant. Future research should evaluate further the hypothesis of the role of passively perceived optical flow in cybersickness, but manipulating the virtual environment'sperrot structure. It also seems that video-gaming experience might be involved in the user's sensitivity to cybersickness.

The ALIVE Project: Astronomy Learning in Immersive Virtual Environments

NASA Astrophysics Data System (ADS)

Yu, K. C.; Sahami, K.; Denn, G.

2008-06-01

The Astronomy Learning in Immersive Virtual Environments (ALIVE) project seeks to discover learning modes and optimal teaching strategies using immersive virtual environments (VEs). VEs are computer-generated, three-dimensional environments that can be navigated to provide multiple perspectives. Immersive VEs provide the additional benefit of surrounding a viewer with the simulated reality. ALIVE evaluates the incorporation of an interactive, real-time ``virtual universe'' into formal college astronomy education. In the experiment, pre-course, post-course, and curriculum tests will be used to determine the efficacy of immersive visualizations presented in a digital planetarium versus the same visual simulations in the non-immersive setting of a normal classroom, as well as a control case using traditional classroom multimedia. To normalize for inter-instructor variability, each ALIVE instructor will teach at least one of each class in each of the three test groups.

The effects of game-based virtual reality movement therapy plus mental practice on upper extremity function in chronic stroke patients with hemiparesis: a randomized controlled trial

PubMed Central

Park, Jin-Hyuck; Park, Ji-Hyuk

2016-01-01

[Purpose] The purpose of this study was to investigate the effects of game-based virtual reality movement therapy plus mental practice on upper extremity function in chronic stroke patients with hemiparesis. [Subjects] The subjects were chronic stroke patients with hemiparesis. [Methods] Thirty subjects were randomly assigned to either the control group or experimental group. All subjects received 20 sessions (5 days in a week) of virtual reality movement therapy using the Nintendo Wii. In addition to Wii-based virtual reality movement therapy, experimental group subjects performed mental practice consisting of 5 minutes of relaxation, Wii games imagination, and normalization phases before the beginning of Wii games. To compare the two groups, the upper extremity subtest of the Fugl-Meyer Assessment, Box and Block Test, and quality of movement subscale of the Motor Activity Log were performed. [Results] Both groups showed statistically significant improvement in the Fugl-Meyer Assessment, Box and Block Test, and quality of the movement subscale of Motor Activity Log after the interventions. Also, there were significant differences in the Fugl-Meyer Assessment, Box and Block Test, and quality of movement subscale of the Motor Activity Log between the two groups. [Conclusion] Game-based virtual reality movement therapy alone may be helpful to improve functional recovery of the upper extremity, but the addition of MP produces a lager improvement. PMID:27134363

Surgical model-view-controller simulation software framework for local and collaborative applications

PubMed Central

Sankaranarayanan, Ganesh; Halic, Tansel; Arikatla, Venkata Sreekanth; Lu, Zhonghua; De, Suvranu

2010-01-01

Purpose Surgical simulations require haptic interactions and collaboration in a shared virtual environment. A software framework for decoupled surgical simulation based on a multi-controller and multi-viewer model-view-controller (MVC) pattern was developed and tested. Methods A software framework for multimodal virtual environments was designed, supporting both visual interactions and haptic feedback while providing developers with an integration tool for heterogeneous architectures maintaining high performance, simplicity of implementation, and straightforward extension. The framework uses decoupled simulation with updates of over 1,000 Hz for haptics and accommodates networked simulation with delays of over 1,000 ms without performance penalty. Results The simulation software framework was implemented and was used to support the design of virtual reality-based surgery simulation systems. The framework supports the high level of complexity of such applications and the fast response required for interaction with haptics. The efficacy of the framework was tested by implementation of a minimally invasive surgery simulator. Conclusion A decoupled simulation approach can be implemented as a framework to handle simultaneous processes of the system at the various frame rates each process requires. The framework was successfully used to develop collaborative virtual environments (VEs) involving geographically distributed users connected through a network, with the results comparable to VEs for local users. PMID:20714933

Surgical model-view-controller simulation software framework for local and collaborative applications.

PubMed

Maciel, Anderson; Sankaranarayanan, Ganesh; Halic, Tansel; Arikatla, Venkata Sreekanth; Lu, Zhonghua; De, Suvranu

2011-07-01

Surgical simulations require haptic interactions and collaboration in a shared virtual environment. A software framework for decoupled surgical simulation based on a multi-controller and multi-viewer model-view-controller (MVC) pattern was developed and tested. A software framework for multimodal virtual environments was designed, supporting both visual interactions and haptic feedback while providing developers with an integration tool for heterogeneous architectures maintaining high performance, simplicity of implementation, and straightforward extension. The framework uses decoupled simulation with updates of over 1,000 Hz for haptics and accommodates networked simulation with delays of over 1,000 ms without performance penalty. The simulation software framework was implemented and was used to support the design of virtual reality-based surgery simulation systems. The framework supports the high level of complexity of such applications and the fast response required for interaction with haptics. The efficacy of the framework was tested by implementation of a minimally invasive surgery simulator. A decoupled simulation approach can be implemented as a framework to handle simultaneous processes of the system at the various frame rates each process requires. The framework was successfully used to develop collaborative virtual environments (VEs) involving geographically distributed users connected through a network, with the results comparable to VEs for local users.

Simulation of Physical Experiments in Immersive Virtual Environments

NASA Technical Reports Server (NTRS)

Noor, Ahmed K.; Wasfy, Tamer M.

2001-01-01

An object-oriented event-driven immersive Virtual environment is described for the creation of virtual labs (VLs) for simulating physical experiments. Discussion focuses on a number of aspects of the VLs, including interface devices, software objects, and various applications. The VLs interface with output devices, including immersive stereoscopic screed(s) and stereo speakers; and a variety of input devices, including body tracking (head and hands), haptic gloves, wand, joystick, mouse, microphone, and keyboard. The VL incorporates the following types of primitive software objects: interface objects, support objects, geometric entities, and finite elements. Each object encapsulates a set of properties, methods, and events that define its behavior, appearance, and functions. A container object allows grouping of several objects. Applications of the VLs include viewing the results of the physical experiment, viewing a computer simulation of the physical experiment, simulation of the experiments procedure, computational steering, and remote control of the physical experiment. In addition, the VL can be used as a risk-free (safe) environment for training. The implementation of virtual structures testing machines, virtual wind tunnels, and a virtual acoustic testing facility is described.

The effectiveness of virtual reality interventions in improving balance in adults with impaired balance compared with standard or no treatment: a systematic review and meta-analysis.

PubMed

Booth, Vicky; Masud, Tahir; Connell, Louise; Bath-Hextall, Fiona

2014-05-01

To evaluate whether virtual reality interventions, including interactive gaming systems, are effective at improving balance in adults with impaired balance. Systematic review and meta-analysis of randomized control trials. Studies were identified from electronic databases (CENTRAL, MEDLINE, EMBASE, AMED, CINAHL, PyschINFO, PyschBITE, OTseeker, Ei Compendex, and Inspec) searched to November 2011, and repeated in November 2012. Two reviewers selected studies meeting inclusion criteria and quality of included studies assessed using a Joanna Briggs Institute appraisal tool. Data was pooled and a meta-analysis completed. The systematic review was reported following guidance of the PRISMA statement. A total of 251 articles were screened. Eight randomized control trials were included. These studies presented the results of 239 participants, with various aetiologies, and used a variety of virtual reality systems. The number of falls was documented in only one included study. Meta-analysis was completed on data from the Berg Balance Scale, walking speed, 30 second sit-to-stand test, and Timed Up and Go Test, and favoured standard therapy when compared with standard plus virtual reality interventions. There was a notable inconsistency in the outcome measures, experimental, and control interventions used within the included studies. The pooled results of the studies showed no significant difference. Therefore this review cannot support nor refute the use of virtual reality interventions, rather than conventional physiotherapy, to improve balance in adults with impaired balance.

Educating resident physicians using virtual case-based simulation improves diabetes management: a randomized controlled trial.

PubMed

Sperl-Hillen, JoAnn; O'Connor, Patrick J; Ekstrom, Heidi L; Rush, William A; Asche, Stephen E; Fernandes, Omar D; Appana, Deepika; Amundson, Gerald H; Johnson, Paul E; Curran, Debra M

2014-12-01

To test a virtual case-based Simulated Diabetes Education intervention (SimDE) developed to teach primary care residents how to manage diabetes. Nineteen primary care residency programs, with 341 volunteer residents in all postgraduate years (PGY), were randomly assigned to a SimDE intervention group or control group (CG). The Web-based interactive educational intervention used computerized virtual patients who responded to provider actions through programmed simulation models. Eighteen distinct learning cases (L-cases) were assigned to SimDE residents over six months from 2010 to 2011. Impact was assessed using performance on four virtual assessment cases (A-cases), an objective knowledge test, and pre-post changes in self-assessed diabetes knowledge and confidence. Group comparisons were analyzed using generalized linear mixed models, controlling for clustering of residents within residency programs and differences in baseline knowledge. The percentages of residents appropriately achieving A-case composite clinical goals for glucose, blood pressure, and lipids were as follows: A-case 1: SimDE = 21.2%, CG = 1.8%, P = .002; A-case 2: SimDE = 15.7%, CG = 4.7%, P = .02; A-case 3: SimDE = 48.0%, CG = 10.4%, P < .001; and A-case 4: SimDE = 42.1%, CG = 18.7%, P = .004. The mean knowledge score and pre-post changes in self-assessed knowledge and confidence were significantly better for SimDE group than CG participants. A virtual case-based simulated diabetes education intervention improved diabetes management skills, knowledge, and confidence for primary care residents.

Virtual Instrument Simulator for CERES

NASA Technical Reports Server (NTRS)

Chapman, John J.

1997-01-01

A benchtop virtual instrument simulator for CERES (Clouds and the Earth's Radiant Energy System) has been built at NASA, Langley Research Center in Hampton, VA. The CERES instruments will fly on several earth orbiting platforms notably NASDA's Tropical Rainfall Measurement Mission (TRMM) and NASA's Earth Observing System (EOS) satellites. CERES measures top of the atmosphere radiative fluxes using microprocessor controlled scanning radiometers. The CERES Virtual Instrument Simulator consists of electronic circuitry identical to the flight unit's twin microprocessors and telemetry interface to the supporting spacecraft electronics and two personal computers (PC) connected to the I/O ports that control azimuth and elevation gimbals. Software consists of the unmodified TRW developed Flight Code and Ground Support Software which serves as the instrument monitor and NASA/TRW developed engineering models of the scanners. The CERES Instrument Simulator will serve as a testbed for testing of custom instrument commands intended to solve in-flight anomalies of the instruments which could arise during the CERES mission. One of the supporting computers supports the telemetry display which monitors the simulator microprocessors during the development and testing of custom instrument commands. The CERES engineering development software models have been modified to provide a virtual instrument running on a second supporting computer linked in real time to the instrument flight microprocessor control ports. The CERES Instrument Simulator will be used to verify memory uploads by the CERES Flight Operations TEAM at NASA. Plots of the virtual scanner models match the actual instrument scan plots. A high speed logic analyzer has been used to track the performance of the flight microprocessor. The concept of using an identical but non-flight qualified microprocessor and electronics ensemble linked to a virtual instrument with identical system software affords a relatively inexpensive simulation system capable of high fidelity.

Anxiety provocation and measurement using virtual reality in patients with obsessive-compulsive disorder.

PubMed

Kim, Kwanguk; Kim, Chan-Hyung; Cha, Kyung Ryeol; Park, Junyoung; Han, Kiwan; Kim, Yun Ki; Kim, Jae-Jin; Kim, In Young; Kim, Sun I

2008-12-01

The current study is a preliminary test of a virtual reality (VR) anxiety-provoking tool using a sample of participants with obsessive-compulsive disorder (OCD). The tasks were administrated to 33 participants with OCD and 30 healthy control participants. In the VR task, participants navigated through a virtual environment using a joystick and head-mounted display. The virtual environment consisted of three phases: training, distraction, and the main task. After the training and distraction phases, participants were allowed to check (a common OCD behavior) freely, as they would in the real world, and a visual analogy scale of anxiety was recorded during VR. Participants' anxiety in the virtual environment was measured with a validated measure of psychiatric symptoms and functions and analyzed with a VR questionnaire. Results revealed that those with OCD had significantly higher anxiety in the virtual environment than did healthy controls, and the decreased ratio of anxiety in participants with OCD was also higher than that of healthy controls. Moreover, the degree of anxiety of an individual with OCD was positively correlated with a his or her symptom score and immersive tendency score. These results suggest the possibility that VR technology has a value as an anxiety-provoking or treatment tool for OCD.

Virtual experiments: a new approach for improving process conceptualization in hillslope hydrology

NASA Astrophysics Data System (ADS)

Weiler, Markus; McDonnell, Jeff

2004-01-01

We present an approach for process conceptualization in hillslope hydrology. We develop and implement a series of virtual experiments, whereby the interaction between water flow pathways, source and mixing at the hillslope scale is examined within a virtual experiment framework. We define these virtual experiments as 'numerical experiments with a model driven by collective field intelligence'. The virtual experiments explore the first-order controls in hillslope hydrology, where the experimentalist and modeler work together to cooperatively develop and analyze the results. Our hillslope model for the virtual experiments (HillVi) in this paper is based on conceptualizing the water balance within the saturated and unsaturated zone in relation to soil physical properties in a spatially explicit manner at the hillslope scale. We argue that a virtual experiment model needs to be able to capture all major controls on subsurface flow processes that the experimentalist might deem important, while at the same time being simple with few 'tunable parameters'. This combination makes the approach, and the dialog between experimentalist and modeler, a useful hypothesis testing tool. HillVi simulates mass flux for different initial conditions under the same flow conditions. We analyze our results in terms of an artificial line source and isotopic hydrograph separation of water and subsurface flow. Our results for this first set of virtual experiments showed how drainable porosity and soil depth variability exert a first order control on flow and transport at the hillslope scale. We found that high drainable porosity soils resulted in a restricted water table rise, resulting in more pronounced channeling of lateral subsurface flow along the soil-bedrock interface. This in turn resulted in a more anastomosing network of tracer movement across the slope. The virtual isotope hydrograph separation showed higher proportions of event water with increasing drainable porosity. When combined with previous experimental findings and conceptualizations, virtual experiments can be an effective way to isolate certain controls and examine their influence over a range of rainfall and antecedent wetness conditions.

Review of Enabling Technologies to Facilitate Secure Compute Customization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aderholdt, Ferrol; Caldwell, Blake A; Hicks, Susan Elaine

High performance computing environments are often used for a wide variety of workloads ranging from simulation, data transformation and analysis, and complex workflows to name just a few. These systems may process data for a variety of users, often requiring strong separation between job allocations. There are many challenges to establishing these secure enclaves within the shared infrastructure of high-performance computing (HPC) environments. The isolation mechanisms in the system software are the basic building blocks for enabling secure compute enclaves. There are a variety of approaches and the focus of this report is to review the different virtualization technologies thatmore » facilitate the creation of secure compute enclaves. The report reviews current operating system (OS) protection mechanisms and modern virtualization technologies to better understand the performance/isolation properties. We also examine the feasibility of running ``virtualized'' computing resources as non-privileged users, and providing controlled administrative permissions for standard users running within a virtualized context. Our examination includes technologies such as Linux containers (LXC [32], Docker [15]) and full virtualization (KVM [26], Xen [5]). We categorize these different approaches to virtualization into two broad groups: OS-level virtualization and system-level virtualization. The OS-level virtualization uses containers to allow a single OS kernel to be partitioned to create Virtual Environments (VE), e.g., LXC. The resources within the host's kernel are only virtualized in the sense of separate namespaces. In contrast, system-level virtualization uses hypervisors to manage multiple OS kernels and virtualize the physical resources (hardware) to create Virtual Machines (VM), e.g., Xen, KVM. This terminology of VE and VM, detailed in Section 2, is used throughout the report to distinguish between the two different approaches to providing virtualized execution environments. As part of our technology review we analyzed several current virtualization solutions to assess their vulnerabilities. This included a review of common vulnerabilities and exposures (CVEs) for Xen, KVM, LXC and Docker to gauge their susceptibility to different attacks. The complete details are provided in Section 5 on page 33. Based on this review we concluded that system-level virtualization solutions have many more vulnerabilities than OS level virtualization solutions. As such, security mechanisms like sVirt (Section 3.3) should be considered when using system-level virtualization solutions in order to protect the host against exploits. The majority of vulnerabilities related to KVM, LXC, and Docker are in specific regions of the system. Therefore, future "zero day attacks" are likely to be in the same regions, which suggests that protecting these areas can simplify the protection of the host and maintain the isolation between users. The evaluations of virtualization technologies done thus far are discussed in Section 4. This includes experiments with 'user' namespaces in VEs, which provides the ability to isolate user privileges and allow a user to run with different UIDs within the container while mapping them to non-privileged UIDs in the host. We have identified Linux namespaces as a promising mechanism to isolate shared resources, while maintaining good performance. In Section 4.1 we describe our tests with LXC as a non-root user and leveraging namespaces to control UID/GID mappings and support controlled sharing of parallel file-systems. We highlight several of these namespace capabilities in Section 6.2.3. The other evaluations that were performed during this initial phase of work provide baseline performance data for comparing VEs and VMs to purely native execution. In Section 4.2 we performed tests using the High-Performance Computing Conjugate Gradient (HPCCG) benchmark to establish baseline performance for a scientific application when run on the Native (host) machine in contrast with execution under Docker and KVM. Our tests verified prior studies showing roughly 2-4% overheads in application execution time & MFlops when running in hypervisor-base environments (VMs) as compared to near native performance with VEs. For more details, see Figures 4.5 (page 28), 4.6 (page 28), and 4.7 (page 29). Additionally, in Section 4.3 we include network measurements for TCP bandwidth performance over the 10GigE interface in our testbed. The Native and Docker based tests achieved >= ~9Gbits/sec, while the KVM configuration only achieved 2.5Gbits/sec (Table 4.6 on page 32). This may be a configuration issue with our KVM installation, and is a point for further testing as we refine the network settings in the testbed. The initial network tests were done using a bridged networking configuration. The report outline is as follows: - Section 1 introduces the report and clarifies the scope of the proj...« less

Effect of a Virtual Environment on the Development of Mathematical Skills in Children with Dyscalculia

PubMed Central

de Castro, Marcus Vasconcelos; Bissaco, Márcia Aparecida Silva; Panccioni, Bruno Marques; Rodrigues, Silvia Cristina Martini; Domingues, Andreia Miranda

2014-01-01

In this study, we show the effectiveness of a virtual environment comprising 18 computer games that cover mathematics topics in a playful setting and that can be executed on the Internet with the possibility of player interaction through chat. An arithmetic pre-test contained in the Scholastic Performance Test was administered to 300 children between 7 and 10 years old, including 162 males and 138 females, in the second grade of primary school. Twenty-six children whose scores showed a low level of mathematical knowledge were chosen and randomly divided into the control (CG) and experimental (EG) groups. The EG participated to the virtual environment and the CG participated in reinforcement using traditional teaching methods. Both groups took a post-test in which the Scholastic Performance Test (SPT) was given again. A statistical analysis of the results using the Student's t-test showed a significant learning improvement for the EG and no improvement for the CG (p≤0.05). The virtual environment allows the students to integrate thought, feeling and action, thus motivating the children to learn and contributing to their intellectual development. PMID:25068511

Encountered-Type Haptic Interface for Representation of Shape and Rigidity of 3D Virtual Objects.

PubMed

Takizawa, Naoki; Yano, Hiroaki; Iwata, Hiroo; Oshiro, Yukio; Ohkohchi, Nobuhiro

2017-01-01

This paper describes the development of an encountered-type haptic interface that can generate the physical characteristics, such as shape and rigidity, of three-dimensional (3D) virtual objects using an array of newly developed non-expandable balloons. To alter the rigidity of each non-expandable balloon, the volume of air in it is controlled through a linear actuator and a pressure sensor based on Hooke's law. Furthermore, to change the volume of each balloon, its exposed surface area is controlled by using another linear actuator with a trumpet-shaped tube. A position control mechanism is constructed to display virtual objects using the balloons. The 3D position of each balloon is controlled using a flexible tube and a string. The performance of the system is tested and the results confirm the effectiveness of the proposed principle and interface.

Flight Test Overview for UAS Integration in the NAS Project

NASA Technical Reports Server (NTRS)

Murphy, James R.; Hayes, Peggy S.; Kim, Sam K.; Bridges, Wayne; Marston, Michael

2016-01-01

The National Aeronautics and Space Administration is conducting a series of flight tests intended to support the reduction of barriers that prevent unmanned aircraft from flying without the required waivers from the Federal Aviation Administration. The most recent testing supported two separate test configurations. The first investigated the timing of Detect and Avoid (DAA) alerting thresholds using a radar-equipped unmanned vehicle and multiple live intruders flown at varying encounter geometries. The second configuration included a surrogate unmanned vehicle (flown from a ground control station, with a safety pilot on board) flying a mission in a virtual air traffic control airspace sector using research pilot displays and DAA advisories to maintain separation from live and virtual aircraft. The test was conducted over a seven-week span in the summer of 2015. The data from over 100 encounter sorties will be used to inform the RTCA Phase 1 Detect and Avoid and Command and Control Minimum Operating Performance Standards (MOPS) intended to be completed by the summer of 2016. Follow-on flight-testing is planned for the spring of 2016 to capture remaining encounters and support validation of the MOPS.

Virtual Oscillator Controls | Grid Modernization | NREL

Science.gov Websites

Virtual Oscillator Controls Virtual Oscillator Controls NREL is developing virtual oscillator Santa-Barbara, and SunPower. Publications Synthesizing Virtual Oscillators To Control Islanded Inverters Synchronization of Parallel Single-Phase Inverters Using Virtual Oscillator Control, IEEE Transactions on Power

Virtual blood bank

PubMed Central

Wong, Kit Fai

2011-01-01

Virtual blood bank is the computer-controlled, electronically linked information management system that allows online ordering and real-time, remote delivery of blood for transfusion. It connects the site of testing to the point of care at a remote site in a real-time fashion with networked computers thus maintaining the integrity of immunohematology test results. It has taken the advantages of information and communication technologies to ensure the accuracy of patient, specimen and blood component identification and to enhance personnel traceability and system security. The built-in logics and process constraints in the design of the virtual blood bank can guide the selection of appropriate blood and minimize transfusion risk. The quality of blood inventory is ascertained and monitored, and an audit trail for critical procedures in the transfusion process is provided by the paperless system. Thus, the virtual blood bank can help ensure that the right patient receives the right amount of the right blood component at the right time. PMID:21383930

U.S. Forest Service termiticide tests

Treesearch

Terence Wagner

2003-01-01

The U.S. Forest Service has been testingchemicals for termite control since 1939. Today its termiticide testing program is nationally recognized for providing unbiased efficacy data for product registration using standardized tests, sites, and evaluation procedures. Virtually all termiticides undergo Forest Service testing before being registered by EPA. Termiticides...

Evidence for enhanced discrimination of virtual auditory distance among blind listeners using level and direct-to-reverberant cues.

PubMed

Kolarik, Andrew J; Cirstea, Silvia; Pardhan, Shahina

2013-02-01

Totally blind listeners often demonstrate better than normal capabilities when performing spatial hearing tasks. Accurate representation of three-dimensional auditory space requires the processing of available distance information between the listener and the sound source; however, auditory distance cues vary greatly depending upon the acoustic properties of the environment, and it is not known which distance cues are important to totally blind listeners. Our data show that totally blind listeners display better performance compared to sighted age-matched controls for distance discrimination tasks in anechoic and reverberant virtual rooms simulated using a room-image procedure. Totally blind listeners use two major auditory distance cues to stationary sound sources, level and direct-to-reverberant ratio, more effectively than sighted controls for many of the virtual distances tested. These results show that significant compensation among totally blind listeners for virtual auditory spatial distance leads to benefits across a range of simulated acoustic environments. No significant differences in performance were observed between listeners with partial non-correctable visual losses and sighted controls, suggesting that sensory compensation for virtual distance does not occur for listeners with partial vision loss.

Using mixed methods to evaluate efficacy and user expectations of a virtual reality-based training system for upper-limb recovery in patients after stroke: a study protocol for a randomised controlled trial.

PubMed

Schuster-Amft, Corina; Eng, Kynan; Lehmann, Isabelle; Schmid, Ludwig; Kobashi, Nagisa; Thaler, Irène; Verra, Martin L; Henneke, Andrea; Signer, Sandra; McCaskey, Michael; Kiper, Daniel

2014-09-06

In recent years, virtual reality has been introduced to neurorehabilitation, in particular with the intention of improving upper-limb training options and facilitating motor function recovery. The proposed study incorporates a quantitative part and a qualitative part, termed a mixed-methods approach: (1) a quantitative investigation of the efficacy of virtual reality training compared to conventional therapy in upper-limb motor function are investigated, (2a) a qualitative investigation of patients' experiences and expectations of virtual reality training and (2b) a qualitative investigation of therapists' experiences using the virtual reality training system in the therapy setting. At three participating clinics, 60 patients at least 6 months after stroke onset will be randomly allocated to an experimental virtual reality group (EG) or to a control group that will receive conventional physiotherapy or occupational therapy (16 sessions, 45 minutes each, over the course of 4 weeks). Using custom data gloves, patients' finger and arm movements will be displayed in real time on a monitor, and they will move and manipulate objects in various virtual environments. A blinded assessor will test patients' motor and cognitive performance twice before, once during, and twice after the 4-week intervention. The primary outcome measure is the Box and Block Test. Secondary outcome measures are the Chedoke-McMaster Stroke Assessments (hand, arm and shoulder pain subscales), the Chedoke-McMaster Arm and Hand Activity Inventory, the Line Bisection Test, the Stroke Impact Scale, the MiniMentalState Examination and the Extended Barthel Index. Semistructured face-to-face interviews will be conducted with patients in the EG after intervention finalization with a focus on the patients' expectations and experiences regarding the virtual reality training. Therapists' perspectives on virtual reality training will be reviewed in three focus groups comprising four to six occupational therapists and physiotherapists. The interviews will help to gain a deeper understanding of the phenomena under investigation to provide sound recommendations for the implementation of the virtual reality training system for routine use in neurorehabilitation complementing the quantitative clinical assessments. Cliniclatrials.gov Identifier: NCT01774669 (15 January 2013).

Miniaturized haploscope for testing binocular vision

NASA Technical Reports Server (NTRS)

Decker, T. A.

1973-01-01

Device can reproduce virtually all binocular stimulus conditions (target configuration, vergence angle, and accommodative distance) used to test binocular performance. All subsystems of electronic controls are open-loop and solid-state-controlled and, with the exception of vergence angle drive, utilize dc stepping motors as prime movers. Arrangement is also made for readouts of each variable.

Virtual reality and paranoid ideations in people with an 'at-risk mental state' for psychosis.

PubMed

Valmaggia, Lucia R; Freeman, Daniel; Green, Catherine; Garety, Philippa; Swapp, David; Antley, Angus; Prescott, Corinne; Fowler, David; Kuipers, Elizabeth; Bebbington, Paul; Slater, Mel; Broome, Matthew; McGuire, Philip K

2007-12-01

Virtual reality provides a means of studying paranoid thinking in controlled laboratory conditions. However, this method has not been used with a clinical group. To establish the feasibility and safety of using virtual reality methodology in people with an at-risk mental state and to investigate the applicability of a cognitive model of paranoia to this group. Twenty-one participants with an at-risk mental state were assessed before and after entering a virtual reality environment depicting the inside of an underground train. Virtual reality did not raise levels of distress at the time of testing or cause adverse experiences over the subsequent week. Individuals attributed mental states to virtual reality characters including hostile intent. Persecutory ideation in virtual reality was predicted by higher levels of trait paranoia, anxiety, stress, immersion in virtual reality, perseveration and interpersonal sensitivity. Virtual reality is an acceptable experimental technique for use with individuals with at-risk mental states. Paranoia in virtual reality was understandable in terms of the cognitive model of persecutory delusions.

Smoking cues in a virtual world provoke craving in cigarette smokers.

PubMed

Baumann, Stephen B; Sayette, Michael A

2006-12-01

Twenty smoking-deprived cigarette smokers participated in a study to test the ability of smoking cues within a virtual world to provoke self-reported craving to smoke. Participants were exposed to 2 virtual-reality simulations displayed on a computer monitor: a control environment not containing any intentional smoking stimuli and a cue-exposure environment containing smoking stimuli. At various points, participants rated their urge to smoke on a scale of 0-100. Results indicated that baseline urge ratings were equivalent in both conditions, but the maximum increase in urge ratings was significantly higher in the cue-exposure environment than in the control environment. This is comparable to what in vivo studies have reported, but with the advantage of simulating more naturalistic and complex settings in a controlled environment. (c) 2006 APA, all rights reserved

Wearable Virtual White Cane Network for navigating people with visual impairment.

PubMed

Gao, Yabiao; Chandrawanshi, Rahul; Nau, Amy C; Tse, Zion Tsz Ho

2015-09-01

Navigating the world with visual impairments presents inconveniences and safety concerns. Although a traditional white cane is the most commonly used mobility aid due to its low cost and acceptable functionality, electronic traveling aids can provide more functionality as well as additional benefits. The Wearable Virtual Cane Network is an electronic traveling aid that utilizes ultrasound sonar technology to scan the surrounding environment for spatial information. The Wearable Virtual Cane Network is composed of four sensing nodes: one on each of the user's wrists, one on the waist, and one on the ankle. The Wearable Virtual Cane Network employs vibration and sound to communicate object proximity to the user. While conventional navigation devices are typically hand-held and bulky, the hands-free design of our prototype allows the user to perform other tasks while using the Wearable Virtual Cane Network. When the Wearable Virtual Cane Network prototype was tested for distance resolution and range detection limits at various displacements and compared with a traditional white cane, all participants performed significantly above the control bar (p < 4.3 × 10(-5), standard t-test) in distance estimation. Each sensor unit can detect an object with a surface area as small as 1 cm(2) (1 cm × 1 cm) located 70 cm away. Our results showed that the walking speed for an obstacle course was increased by 23% on average when subjects used the Wearable Virtual Cane Network rather than the white cane. The obstacle course experiment also shows that the use of the white cane in combination with the Wearable Virtual Cane Network can significantly improve navigation over using either the white cane or the Wearable Virtual Cane Network alone (p < 0.05, paired t-test). © IMechE 2015.

Virtual automation.

PubMed

Casis, E; Garrido, A; Uranga, B; Vives, A; Zufiaurre, C

2001-01-01

Total laboratory automation (TLA) can be substituted in mid-size laboratories by a computer sample workflow control (virtual automation). Such a solution has been implemented in our laboratory using PSM, software developed in cooperation with Roche Diagnostics (Barcelona, Spain), to this purpose. This software is connected to the online analyzers and to the laboratory information system and is able to control and direct the samples working as an intermediate station. The only difference with TLA is the replacement of transport belts by personnel of the laboratory. The implementation of this virtual automation system has allowed us the achievement of the main advantages of TLA: workload increase (64%) with reduction in the cost per test (43%), significant reduction in the number of biochemistry primary tubes (from 8 to 2), less aliquoting (from 600 to 100 samples/day), automation of functional testing, drastic reduction of preanalytical errors (from 11.7 to 0.4% of the tubes) and better total response time for both inpatients (from up to 48 hours to up to 4 hours) and outpatients (from up to 10 days to up to 48 hours). As an additional advantage, virtual automation could be implemented without hardware investment and significant headcount reduction (15% in our lab).

Open core control software for surgical robots.

PubMed

Arata, Jumpei; Kozuka, Hiroaki; Kim, Hyung Wook; Takesue, Naoyuki; Vladimirov, B; Sakaguchi, Masamichi; Tokuda, Junichi; Hata, Nobuhiko; Chinzei, Kiyoyuki; Fujimoto, Hideo

2010-05-01

In these days, patients and doctors in operation room are surrounded by many medical devices as resulting from recent advancement of medical technology. However, these cutting-edge medical devices are working independently and not collaborating with each other, even though the collaborations between these devices such as navigation systems and medical imaging devices are becoming very important for accomplishing complex surgical tasks (such as a tumor removal procedure while checking the tumor location in neurosurgery). On the other hand, several surgical robots have been commercialized, and are becoming common. However, these surgical robots are not open for collaborations with external medical devices in these days. A cutting-edge "intelligent surgical robot" will be possible in collaborating with surgical robots, various kinds of sensors, navigation system and so on. On the other hand, most of the academic software developments for surgical robots are "home-made" in their research institutions and not open to the public. Therefore, open source control software for surgical robots can be beneficial in this field. From these perspectives, we developed Open Core Control software for surgical robots to overcome these challenges. In general, control softwares have hardware dependencies based on actuators, sensors and various kinds of internal devices. Therefore, these control softwares cannot be used on different types of robots without modifications. However, the structure of the Open Core Control software can be reused for various types of robots by abstracting hardware dependent parts. In addition, network connectivity is crucial for collaboration between advanced medical devices. The OpenIGTLink is adopted in Interface class which plays a role to communicate with external medical devices. At the same time, it is essential to maintain the stable operation within the asynchronous data transactions through network. In the Open Core Control software, several techniques for this purpose were introduced. Virtual fixture is well known technique as a "force guide" for supporting operators to perform precise manipulation by using a master-slave robot. The virtual fixture for precise and safety surgery was implemented on the system to demonstrate an idea of high-level collaboration between a surgical robot and a navigation system. The extension of virtual fixture is not a part of the Open Core Control system, however, the function such as virtual fixture cannot be realized without a tight collaboration between cutting-edge medical devices. By using the virtual fixture, operators can pre-define an accessible area on the navigation system, and the area information can be transferred to the robot. In this manner, the surgical console generates the reflection force when the operator tries to get out from the pre-defined accessible area during surgery. The Open Core Control software was implemented on a surgical master-slave robot and stable operation was observed in a motion test. The tip of the surgical robot was displayed on a navigation system by connecting the surgical robot with a 3D position sensor through the OpenIGTLink. The accessible area was pre-defined before the operation, and the virtual fixture was displayed as a "force guide" on the surgical console. In addition, the system showed stable performance in a duration test with network disturbance. In this paper, a design of the Open Core Control software for surgical robots and the implementation of virtual fixture were described. The Open Core Control software was implemented on a surgical robot system and showed stable performance in high-level collaboration works. The Open Core Control software is developed to be a widely used platform of surgical robots. Safety issues are essential for control software of these complex medical devices. It is important to follow the global specifications such as a FDA requirement "General Principles of Software Validation" or IEC62304. For following these regulations, it is important to develop a self-test environment. Therefore, a test environment is now under development to test various interference in operation room such as a noise of electric knife by considering safety and test environment regulations such as ISO13849 and IEC60508. The Open Core Control software is currently being developed software in open-source manner and available on the Internet. A communization of software interface is becoming a major trend in this field. Based on this perspective, the Open Core Control software can be expected to bring contributions in this field.

Evaluation of procedural learning transfer from a virtual environment to a real situation: a case study on tank maintenance training.

PubMed

Ganier, Franck; Hoareau, Charlotte; Tisseau, Jacques

2014-01-01

Virtual reality opens new opportunities for operator training in complex tasks. It lowers costs and has fewer constraints than traditional training. The ultimate goal of virtual training is to transfer knowledge gained in a virtual environment to an actual real-world setting. This study tested whether a maintenance procedure could be learnt equally well by virtual-environment and conventional training. Forty-two adults were divided into three equally sized groups: virtual training (GVT® [generic virtual training]), conventional training (using a real tank suspension and preparation station) and control (no training). Participants then performed the procedure individually in the real environment. Both training types (conventional and virtual) produced similar levels of performance when the procedure was carried out in real conditions. Performance level for the two trained groups was better in terms of success and time taken to complete the task, time spent consulting job instructions and number of times the instructor provided guidance.

Development of an effective virtual environment in eliciting craving in adolescents and young adults with internet gaming disorder.

PubMed

Shin, Yu-Bin; Kim, Jae-Jin; Kim, Min-Kyeong; Kyeong, Sunghyon; Jung, Young Hoon; Eom, Hyojung; Kim, Eunjoo

2018-01-01

Internet gaming disorder (IGD) is a new disorder that warrants further investigation, as recently noted in the research criteria of the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition. Offering controlled environments that increase cue-induced craving, virtual reality cue-exposure therapy has been shown to be effective for some addiction disorders. To assess the feasibility of virtual reality for patients with IGD, this study aimed to develop virtual environments that represent risk situations for inducing craving, and assess the effect of virtual reality in cue reactivity. A total of 64 male adolescents and young adults (34 with IGD and 30 without) were recruited for participation. We developed a virtual internet café environment and the participants were exposed to four different tasks. As the primary feasibility outcome, cravings were measured with a visual analogue scale measuring current urge to play a game after exposure to each task. The virtual internet café induced significantly greater cravings in patients with IGD compared to controls. Additionally, patients exhibited a significantly higher acceptance rate of an avatar's invitation to play a game together than that of controls. In IGD, craving response to the tasks was positively associated with the symptom severity score as measured by Young's Internet Addiction Test. These findings reveal that virtual reality laden with complex game-related cues could evoke game craving in patients with IGD and could be used in the treatment of IGD as a cue-exposure therapy tool for eliciting craving.

Development of an effective virtual environment in eliciting craving in adolescents and young adults with internet gaming disorder

PubMed Central

Shin, Yu-Bin; Kim, Jae-Jin; Kim, Min-Kyeong; Kyeong, Sunghyon; Jung, Young Hoon; Eom, Hyojung

2018-01-01

Internet gaming disorder (IGD) is a new disorder that warrants further investigation, as recently noted in the research criteria of the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition. Offering controlled environments that increase cue-induced craving, virtual reality cue-exposure therapy has been shown to be effective for some addiction disorders. To assess the feasibility of virtual reality for patients with IGD, this study aimed to develop virtual environments that represent risk situations for inducing craving, and assess the effect of virtual reality in cue reactivity. A total of 64 male adolescents and young adults (34 with IGD and 30 without) were recruited for participation. We developed a virtual internet café environment and the participants were exposed to four different tasks. As the primary feasibility outcome, cravings were measured with a visual analogue scale measuring current urge to play a game after exposure to each task. The virtual internet café induced significantly greater cravings in patients with IGD compared to controls. Additionally, patients exhibited a significantly higher acceptance rate of an avatar’s invitation to play a game together than that of controls. In IGD, craving response to the tasks was positively associated with the symptom severity score as measured by Young's Internet Addiction Test. These findings reveal that virtual reality laden with complex game-related cues could evoke game craving in patients with IGD and could be used in the treatment of IGD as a cue-exposure therapy tool for eliciting craving. PMID:29672530

A comparative analysis of dynamic grids vs. virtual grids using the A3pviGrid framework.

PubMed

Shankaranarayanan, Avinas; Amaldas, Christine

2010-11-01

With the proliferation of Quad/Multi-core micro-processors in mainstream platforms such as desktops and workstations; a large number of unused CPU cycles can be utilized for running virtual machines (VMs) as dynamic nodes in distributed environments. Grid services and its service oriented business broker now termed cloud computing could deploy image based virtualization platforms enabling agent based resource management and dynamic fault management. In this paper we present an efficient way of utilizing heterogeneous virtual machines on idle desktops as an environment for consumption of high performance grid services. Spurious and exponential increases in the size of the datasets are constant concerns in medical and pharmaceutical industries due to the constant discovery and publication of large sequence databases. Traditional algorithms are not modeled at handing large data sizes under sudden and dynamic changes in the execution environment as previously discussed. This research was undertaken to compare our previous results with running the same test dataset with that of a virtual Grid platform using virtual machines (Virtualization). The implemented architecture, A3pviGrid utilizes game theoretic optimization and agent based team formation (Coalition) algorithms to improve upon scalability with respect to team formation. Due to the dynamic nature of distributed systems (as discussed in our previous work) all interactions were made local within a team transparently. This paper is a proof of concept of an experimental mini-Grid test-bed compared to running the platform on local virtual machines on a local test cluster. This was done to give every agent its own execution platform enabling anonymity and better control of the dynamic environmental parameters. We also analyze performance and scalability of Blast in a multiple virtual node setup and present our findings. This paper is an extension of our previous research on improving the BLAST application framework using dynamic Grids on virtualization platforms such as the virtual box.

Improving flexible thinking in deaf and hard of hearing children with virtual reality technology.

PubMed

Passig, D; Eden, S

2000-07-01

The study investigated whether rotating three-dimensional (3-D) objects using virtual reality (VR) will affect flexible thinking in deaf and hard of hearing children. Deaf and hard of hearing subjects were distributed into experimental and control groups. The experimental group played virtual 3-D Tetris (a game using VR technology) individually, 15 minutes once weekly over 3 months. The control group played conventional two-dimensional (2-D) Tetris over the same period. Children with normal hearing participated as a second control group in order to establish whether deaf and hard of hearing children really are disadvantaged in flexible thinking. Before-and-after testing showed significantly improved flexible thinking in the experimental group; the deaf and hard of hearing control group showed no significant improvement. Also, before the experiment, the deaf and hard of hearing children scored lower in flexible thinking than the children with normal hearing. After the experiment, the difference between the experimental group and the control group of children with normal hearing was smaller.

Effects of substituting a portion of standard physiotherapy time with virtual reality games among community-dwelling stroke survivors.

PubMed

Singh, Devinder Kaur Ajit; Mohd Nordin, Nor Azlin; Abd Aziz, Noor Azah; Lim, Beng Kooi; Soh, Li Ching

2013-12-13

Evidence indicates that the continuation of therapy among community-dwelling stroke survivors improves physical function. Community rehabilitation programmes often face limitations in terms of resources. It is imperative to include new motivational interventions to encourage some level of non-clinician management. The aim of this study was to determine whether there were any changes in physical function and activities of daily living when substituting a portion of the standard physiotherapy time with virtual reality games among community-dwelling stroke survivors. In this controlled trial, the experimental group received 30 minutes of virtual reality balance games in addition to 90 minutes of standard physiotherapy. The control group continued with their two hours of routine standard physiotherapy. Both groups received 12 therapy sessions: two-hour sessions twice per week for six continuous weeks. Changes in physical function, activities of daily living and balance ability were assessed using the Timed Up and Go test, 30-second Sit to Stand test, Timed Ten-Metre Walk test, Six-Minute Walk test and the Barthel Index, and static balance was assessed using a probalance board. Twenty-eight participants completed post-intervention assessments. The results showed a significant within-subject effect on the Timed Up and Go test: F (1, 26) = 5.83, p = 0.02; and the 30-second Sit to Stand test; F (1, 26) = 13.50, p = 0.001. The between-subject effect was not significant (p > 0.05) for any of the outcome measurements. Substituting a portion of the standard physiotherapy time with virtual reality games was equally effective in maintaining physical function outcomes and activities of daily living among community-dwelling stroke survivors. Australia and New Zealand Clinical Trials Register, ACTRN12613000478718.

Virtual Reality Skills Training for Health Care Professionals in Alcohol Screening and Brief Intervention

PubMed Central

Fleming, Michael; Olsen, Dale; Stathes, Hilary; Boteler, Laura; Grossberg, Paul; Pfeifer, Judie; Schiro, Stephanie; Banning, Jane; Skochelak, Susan

2009-01-01

Background Educating physicians and other health care professionals to identify and treat patients who drink above recommended limits is an ongoing challenge. Methods An educational Randomized Control Trial (RCT) was conducted to test the ability of a stand alone training simulation to improve the clinical skills of health care professionals in alcohol screening and intervention. The “virtual reality simulation” combines video, voice recognition and non branching logic to create an interactive environment that allows trainees to encounter complex social cues and realistic interpersonal exchanges. The simulation includes 707 questions and statements and 1207 simulated patient responses. Results A sample of 102 health care professionals (10 physicians; 30 physician assistants [PAs] or nurse practitioners [NPs]; 36 medical students; 26 pharmacy, PA or NP students) were randomly assigned to no training (n=51) or a computer based virtual reality intervention (n=51). Subjects in both groups had similar pre-test standardized patient alcohol screening skill scores – 53.2 (experimental) vs. 54.4 (controls), 52.2 vs. 53.7 alcohol brief intervention skills, and 42.9 vs. 43.5 alcohol referral skills. Following repeated practice with the simulation there were significant increases in the scores of the experimental group at 6 months post-randomization compared to the control group for the screening (67.7 vs. 58.1, p<.001) and brief intervention (58.3 vs. 51.6, p<.04) scenarios. Conclusions The technology tested in this trial is the first virtual reality simulation to demonstrate an increase in the alcohol screening and brief intervention skills of health care professionals. PMID:19587253

Comparing two methods of education (virtual versus traditional) on learning of Iranian dental students: a post-test only design study.

PubMed

Moazami, Fariborz; Bahrampour, Ehsan; Azar, Mohammad Reza; Jahedi, Farzad; Moattari, Marzieh

2014-03-05

The importance of using technologies such as e-learning in different disciplines is discussed in the literature. Researchers have measured the effectiveness of e-learning in a number of fields.Considering the lack of research on the effectiveness of online learning in dental education particularly in Iran, the advantages of these learning methods and the positive university atmosphere regarding the use of online learning. This study, therefore, aims to compare the effects of two methods of teaching (virtual versus traditional) on student learning. This post-test only design study approached 40, fifth year dental students of Shiraz University of Medical Sciences. From this group, 35 students agreed to participate. These students were randomly allocated into two groups, experimental (virtual learning) and comparison (traditional learning). To ensure similarity between groups, we compared GPAs of all participants by the Mann-Whitney U test (P > 0.05). The experimental group received a virtual learning environment courseware package specifically designed for this study, whereas the control group received the same module structured in a traditional lecture form. The virtual learning environment consisted of online and offline materials. Two identical valid, reliable post-tests that consisted of 40 multiple choice questions (MCQs) and 4 essay questions were administered immediately (15 min) after the last session and two months later to assess for knowledge retention. Data were analyzed by SPSS version 20. A comparison of the mean knowledge score of both groups showed that virtual learning was more effective than traditional learning (effect size = 0.69). The newly designed virtual learning package is feasible and will result in more effective learning in comparison with lecture-based training. However further studies are needed to generalize the findings of this study.

Integration of the SSPM and STAGE with the MPACT Virtual Facility Distributed Test Bed.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cipiti, Benjamin B.; Shoman, Nathan

The Material Protection Accounting and Control Technologies (MPACT) program within DOE NE is working toward a 2020 milestone to demonstrate a Virtual Facility Distributed Test Bed. The goal of the Virtual Test Bed is to link all MPACT modeling tools, technology development, and experimental work to create a Safeguards and Security by Design capability for fuel cycle facilities. The Separation and Safeguards Performance Model (SSPM) forms the core safeguards analysis tool, and the Scenario Toolkit and Generation Environment (STAGE) code forms the core physical security tool. These models are used to design and analyze safeguards and security systems and generatemore » performance metrics. Work over the past year has focused on how these models will integrate with the other capabilities in the MPACT program and specific model changes to enable more streamlined integration in the future. This report describes the model changes and plans for how the models will be used more collaboratively. The Virtual Facility is not designed to integrate all capabilities into one master code, but rather to maintain stand-alone capabilities that communicate results between codes more effectively.« less

Research and realization of signal simulation on virtual instrument

NASA Astrophysics Data System (ADS)

Zhao, Qi; He, Wenting; Guan, Xiumei

2010-02-01

In the engineering project, arbitrary waveform generator controlled by software interface is needed by simulation and test. This article discussed the program using the SCPI (Standard Commands For Programmable Instruments) protocol and the VISA (Virtual Instrument System Architecture) library to control the Agilent signal generator (Agilent N5182A) by instrument communication over the LAN interface. The program can conduct several signal generations such as CW (continuous wave), AM (amplitude modulation), FM (frequency modulation), ΦM (phase modulation), Sweep. As the result, the program system has good operability and portability.

Intelligent Launch and Range Operations Virtual Test Bed (ILRO-VTB)

NASA Technical Reports Server (NTRS)

Bardina, Jorge; Rajkumar, T.

2003-01-01

Intelligent Launch and Range Operations Virtual Test Bed (ILRO-VTB) is a real-time web-based command and control, communication, and intelligent simulation environment of ground-vehicle, launch and range operation activities. ILRO-VTB consists of a variety of simulation models combined with commercial and indigenous software developments (NASA Ames). It creates a hybrid software/hardware environment suitable for testing various integrated control system components of launch and range. The dynamic interactions of the integrated simulated control systems are not well understood. Insight into such systems can only be achieved through simulation/emulation. For that reason, NASA has established a VTB where we can learn the actual control and dynamics of designs for future space programs, including testing and performance evaluation. The current implementation of the VTB simulates the operations of a sub-orbital vehicle of mission, control, ground-vehicle engineering, launch and range operations. The present development of the test bed simulates the operations of Space Shuttle Vehicle (SSV) at NASA Kennedy Space Center. The test bed supports a wide variety of shuttle missions with ancillary modeling capabilities like weather forecasting, lightning tracker, toxic gas dispersion model, debris dispersion model, telemetry, trajectory modeling, ground operations, payload models and etc. To achieve the simulations, all models are linked using Common Object Request Broker Architecture (CORBA). The test bed provides opportunities for government, universities, researchers and industries to do a real time of shuttle launch in cyber space.

A virtual shopping test for realistic assessment of cognitive function

PubMed Central

2013-01-01

Background Cognitive dysfunction caused by brain injury often prevents a patient from achieving a healthy and high quality of life. By now, each cognitive function is assessed precisely by neuropsychological tests. However, it is also important to provide an overall assessment of the patients’ ability in their everyday life. We have developed a Virtual Shopping Test (VST) using virtual reality technology. The objective of this study was to clarify 1) the significance of VST by comparing VST with other conventional tests, 2) the applicability of VST to brain-damaged patients, and 3) the performance of VST in relation to age differences. Methods The participants included 10 patients with brain damage, 10 age-matched healthy subjects for controls, 10 old healthy subjects, and 10 young healthy subjects. VST and neuropsychological tests/questionnaires about attention, memory and executive function were conducted on the patients, while VST and the Mini-Mental State Examination (MMSE) were conducted on the controls and healthy subjects. Within the VST, the participants were asked to buy four items in the virtual shopping mall quickly in a rational way. The score for evaluation included the number of items bought correctly, the number of times to refer to hints, the number of movements between shops, and the total time spent to complete the shopping. Results Some variables on VST correlated with the scores of conventional assessment about attention and everyday memory. The mean number of times referring to hints and the mean number of movements were significantly larger for the patients with brain damage, and the mean total time was significantly longer for the patients than for the controls. In addition, the mean total time was significantly longer for the old than for the young. Conclusions The results suggest that VST is able to evaluate the ability of attention and everyday memory in patients with brain damage. The time of VST is increased by age. PMID:23777412

A virtual shopping test for realistic assessment of cognitive function.

PubMed

Okahashi, Sayaka; Seki, Keiko; Nagano, Akinori; Luo, Zhiwei; Kojima, Maki; Futaki, Toshiko

2013-06-18

Cognitive dysfunction caused by brain injury often prevents a patient from achieving a healthy and high quality of life. By now, each cognitive function is assessed precisely by neuropsychological tests. However, it is also important to provide an overall assessment of the patients' ability in their everyday life. We have developed a Virtual Shopping Test (VST) using virtual reality technology. The objective of this study was to clarify 1) the significance of VST by comparing VST with other conventional tests, 2) the applicability of VST to brain-damaged patients, and 3) the performance of VST in relation to age differences. The participants included 10 patients with brain damage, 10 age-matched healthy subjects for controls, 10 old healthy subjects, and 10 young healthy subjects. VST and neuropsychological tests/questionnaires about attention, memory and executive function were conducted on the patients, while VST and the Mini-Mental State Examination (MMSE) were conducted on the controls and healthy subjects. Within the VST, the participants were asked to buy four items in the virtual shopping mall quickly in a rational way. The score for evaluation included the number of items bought correctly, the number of times to refer to hints, the number of movements between shops, and the total time spent to complete the shopping. Some variables on VST correlated with the scores of conventional assessment about attention and everyday memory. The mean number of times referring to hints and the mean number of movements were significantly larger for the patients with brain damage, and the mean total time was significantly longer for the patients than for the controls. In addition, the mean total time was significantly longer for the old than for the young. The results suggest that VST is able to evaluate the ability of attention and everyday memory in patients with brain damage. The time of VST is increased by age.

Leap Motion-based virtual reality training for improving motor functional recovery of upper limbs and neural reorganization in subacute stroke patients.

PubMed

Wang, Zun-Rong; Wang, Ping; Xing, Liang; Mei, Li-Ping; Zhao, Jun; Zhang, Tong

2017-11-01

Virtual reality is nowadays used to facilitate motor recovery in stroke patients. Most virtual reality studies have involved chronic stroke patients; however, brain plasticity remains good in acute and subacute patients. Most virtual reality systems are only applicable to the proximal upper limbs (arms) because of the limitations of their capture systems. Nevertheless, the functional recovery of an affected hand is most difficult in the case of hemiparesis rehabilitation after a stroke. The recently developed Leap Motion controller can track the fine movements of both hands and fingers. Therefore, the present study explored the effects of a Leap Motion-based virtual reality system on subacute stroke. Twenty-six subacute stroke patients were assigned to an experimental group that received virtual reality training along with conventional occupational rehabilitation, and a control group that only received conventional rehabilitation. The Wolf motor function test (WMFT) was used to assess the motor function of the affected upper limb; functional magnetic resonance imaging was used to measure the cortical activation. After four weeks of treatment, the motor functions of the affected upper limbs were significantly improved in all the patients, with the improvement in the experimental group being significantly better than in the control group. The action performance time in the WMFT significantly decreased in the experimental group. Furthermore, the activation intensity and the laterality index of the contralateral primary sensorimotor cortex increased in both the experimental and control groups. These results confirmed that Leap Motion-based virtual reality training was a promising and feasible supplementary rehabilitation intervention, could facilitate the recovery of motor functions in subacute stroke patients. The study has been registered in the Chinese Clinical Trial Registry (registration number: ChiCTR-OCH-12002238).

Porcine cadaver organ or virtual-reality simulation training for laparoscopic cholecystectomy: a randomized, controlled trial.

PubMed

Van Bruwaene, Siska; Schijven, Marlies P; Napolitano, Daniel; De Win, Gunter; Miserez, Marc

2015-01-01

As conventional laparoscopic procedural training requires live animals or cadaver organs, virtual simulation seems an attractive alternative. Therefore, we compared the transfer of training for the laparoscopic cholecystectomy from porcine cadaver organs vs virtual simulation to surgery in a live animal model in a prospective randomized trial. After completing an intensive training in basic laparoscopic skills, 3 groups of 10 participants proceeded with no additional training (control group), 5 hours of cholecystectomy training on cadaver organs (= organ training) or proficiency-based cholecystectomy training on the LapMentor (= virtual-reality training). Participants were evaluated on time and quality during a laparoscopic cholecystectomy on a live anaesthetized pig at baseline, 1 week (= post) and 4 months (= retention) after training. All research was performed in the Center for Surgical Technologies, Leuven, Belgium. In total, 30 volunteering medical students without prior experience in laparoscopy or minimally invasive surgery from the University of Leuven (Belgium). The organ training group performed the procedure significantly faster than the virtual trainer and borderline significantly faster than control group at posttesting. Only 1 of 3 expert raters suggested significantly better quality of performance of the organ training group compared with both the other groups at posttesting (p < 0.01). There were no significant differences between groups at retention testing. The virtual trainer group did not outperform the control group at any time. For trainees who are proficient in basic laparoscopic skills, the long-term advantage of additional procedural training, especially on a virtual but also on the conventional organ training model, remains to be proven. Copyright © 2015 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

Leap Motion-based virtual reality training for improving motor functional recovery of upper limbs and neural reorganization in subacute stroke patients

PubMed Central

Wang, Zun-rong; Wang, Ping; Xing, Liang; Mei, Li-ping; Zhao, Jun; Zhang, Tong

2017-01-01

Virtual reality is nowadays used to facilitate motor recovery in stroke patients. Most virtual reality studies have involved chronic stroke patients; however, brain plasticity remains good in acute and subacute patients. Most virtual reality systems are only applicable to the proximal upper limbs (arms) because of the limitations of their capture systems. Nevertheless, the functional recovery of an affected hand is most difficult in the case of hemiparesis rehabilitation after a stroke. The recently developed Leap Motion controller can track the fine movements of both hands and fingers. Therefore, the present study explored the effects of a Leap Motion-based virtual reality system on subacute stroke. Twenty-six subacute stroke patients were assigned to an experimental group that received virtual reality training along with conventional occupational rehabilitation, and a control group that only received conventional rehabilitation. The Wolf motor function test (WMFT) was used to assess the motor function of the affected upper limb; functional magnetic resonance imaging was used to measure the cortical activation. After four weeks of treatment, the motor functions of the affected upper limbs were significantly improved in all the patients, with the improvement in the experimental group being significantly better than in the control group. The action performance time in the WMFT significantly decreased in the experimental group. Furthermore, the activation intensity and the laterality index of the contralateral primary sensorimotor cortex increased in both the experimental and control groups. These results confirmed that Leap Motion-based virtual reality training was a promising and feasible supplementary rehabilitation intervention, could facilitate the recovery of motor functions in subacute stroke patients. The study has been registered in the Chinese Clinical Trial Registry (registration number: ChiCTR-OCH-12002238). PMID:29239328

An optical brain computer interface for environmental control.

PubMed

Ayaz, Hasan; Shewokis, Patricia A; Bunce, Scott; Onaral, Banu

2011-01-01

A brain computer interface (BCI) is a system that translates neurophysiological signals detected from the brain to supply input to a computer or to control a device. Volitional control of neural activity and its real-time detection through neuroimaging modalities are key constituents of BCI systems. The purpose of this study was to develop and test a new BCI design that utilizes intention-related cognitive activity within the dorsolateral prefrontal cortex using functional near infrared (fNIR) spectroscopy. fNIR is a noninvasive, safe, portable and affordable optical technique with which to monitor hemodynamic changes, in the brain's cerebral cortex. Because of its portability and ease of use, fNIR is amenable to deployment in ecologically valid natural working environments. We integrated a control paradigm in a computerized 3D virtual environment to augment interactivity. Ten healthy participants volunteered for a two day study in which they navigated a virtual environment with keyboard inputs, but were required to use the fNIR-BCI for interaction with virtual objects. Results showed that participants consistently utilized the fNIR-BCI with an overall success rate of 84% and volitionally increased their cerebral oxygenation level to trigger actions within the virtual environment.

Virtual Balancing for Studying and Training Postural Control.

PubMed

Buettner, Daniela; Dalin, Daniela; Wiesmeier, Isabella K; Maurer, Christoph

2017-01-01

Postural control during free stance has been frequently interpreted in terms of balancing an inverted pendulum. This even holds, if subjects do not balance their own, but an external body weight. We introduce here a virtual balancing apparatus, which produces torque in the ankle joint as a function of ankle angle resembling the gravity and inertial effects of free standing. As a first aim of this study, we systematically modified gravity, damping, and inertia to examine its effect on postural control beyond the physical constraints given in the real world. As a second aim, we compared virtual balancing to free stance to test its suitability for balance training in patients who are not able to balance their full body weight due to certain medical conditions. In a feasibility study, we analyzed postural control during free stance and virtual balancing in 15 healthy subjects. Postural control was characterized by spontaneous sway measures and measures of perturbed stance. During free stance, perturbations were induced by pseudorandom anterior-posterior tilts of the body support surface. In the virtual balancing task, we systematically varied the anterior-posterior position of the foot plate where the balancing forces are zero following a similar pseudorandom stimulus profile. We found that subjects' behavior during virtual balancing resembles free stance on a tilting platform. This specifically holds for the profile of body excursions as a function of stimulus frequencies. Moreover, non-linearity between stimulus and response amplitude is similar in free and virtual balancing. The overall larger stimulus induced body excursions together with an altered phase behavior between stimulus and response could be in part explained by the limited use of vestibular and visual feedback in our experimental setting. Varying gravity or damping significantly affected postural behavior. Inertia as an isolated factor had a mild effect on the response functions. We conclude that virtual balancing may be well suited to simulate conditions which could otherwise only be realized in space experiments or during parabolic flights. Further studies are needed to examine patients' potential benefit of virtual balance training.

Virtual Balancing for Studying and Training Postural Control

PubMed Central

Buettner, Daniela; Dalin, Daniela; Wiesmeier, Isabella K.; Maurer, Christoph

2017-01-01

Postural control during free stance has been frequently interpreted in terms of balancing an inverted pendulum. This even holds, if subjects do not balance their own, but an external body weight. We introduce here a virtual balancing apparatus, which produces torque in the ankle joint as a function of ankle angle resembling the gravity and inertial effects of free standing. As a first aim of this study, we systematically modified gravity, damping, and inertia to examine its effect on postural control beyond the physical constraints given in the real world. As a second aim, we compared virtual balancing to free stance to test its suitability for balance training in patients who are not able to balance their full body weight due to certain medical conditions. In a feasibility study, we analyzed postural control during free stance and virtual balancing in 15 healthy subjects. Postural control was characterized by spontaneous sway measures and measures of perturbed stance. During free stance, perturbations were induced by pseudorandom anterior-posterior tilts of the body support surface. In the virtual balancing task, we systematically varied the anterior-posterior position of the foot plate where the balancing forces are zero following a similar pseudorandom stimulus profile. We found that subjects' behavior during virtual balancing resembles free stance on a tilting platform. This specifically holds for the profile of body excursions as a function of stimulus frequencies. Moreover, non-linearity between stimulus and response amplitude is similar in free and virtual balancing. The overall larger stimulus induced body excursions together with an altered phase behavior between stimulus and response could be in part explained by the limited use of vestibular and visual feedback in our experimental setting. Varying gravity or damping significantly affected postural behavior. Inertia as an isolated factor had a mild effect on the response functions. We conclude that virtual balancing may be well suited to simulate conditions which could otherwise only be realized in space experiments or during parabolic flights. Further studies are needed to examine patients' potential benefit of virtual balance training. PMID:29018320

A controlled study of agoraphobia and the independent effect of virtual reality exposure therapy.

PubMed

Malbos, Eric; Rapee, Ronald M; Kavakli, Manolya

2013-02-01

Past controlled clinical trials centred on virtual reality exposure therapy (VRET) for agoraphobia mostly used multicomponent therapy with success. However, the present paper aimed to evaluate the independent effect of VRET for agoraphobia. A controlled study involving 18 agoraphobic participants assigned to two groups: VRET only and VRET with cognitive therapy. Nine specific virtual environments were developed using an affordable game level editor. Questionnaires, behavioural tests and physiological measures indicated a positive effect of VRET. Correlations supported the predictive value of presence towards treatment outcome. The addition of cognitive therapy did not provide significant additional benefit. Overall, the isolated effects of VRET did not seem to be significantly less than the effects of VRET combined with cognitive therapy. Future research should explore the use of other components in addition to cognitive therapy and VRET for agoraphobia as well as its possible use in patients' homes.

A novel framework for virtual prototyping of rehabilitation exoskeletons.

PubMed

Agarwal, Priyanshu; Kuo, Pei-Hsin; Neptune, Richard R; Deshpande, Ashish D

2013-06-01

Human-worn rehabilitation exoskeletons have the potential to make therapeutic exercises increasingly accessible to disabled individuals while reducing the cost and labor involved in rehabilitation therapy. In this work, we propose a novel human-model-in-the-loop framework for virtual prototyping (design, control and experimentation) of rehabilitation exoskeletons by merging computational musculoskeletal analysis with simulation-based design techniques. The framework allows to iteratively optimize design and control algorithm of an exoskeleton using simulation. We introduce biomechanical, morphological, and controller measures to quantify the performance of the device for optimization study. Furthermore, the framework allows one to carry out virtual experiments for testing specific "what-if" scenarios to quantify device performance and recovery progress. To illustrate the application of the framework, we present a case study wherein the design and analysis of an index-finger exoskeleton is carried out using the proposed framework.

Developing multimedia software and virtual reality worlds and their use in rehabilitation and psychology.

PubMed

Sik Lányi, Cecília; Laky, Viktória; Tilinger, Adám; Pataky, Ilona; Simon, Lajos; Kiss, Bernadett; Simon, Viktória; Szabó, Júlianna; Páll, Attila

2004-01-01

The multimedia and virtual reality projects performed at our laboratory during the last ten years can be grouped into the following groups: 1) tutorial and entertainment programs for handicapped children, 2) rehabilitation programs for stroke patients and patients with phobias. We have developed multimedia software for handicapped children with various impairments: partial vision, hearing difficulties, locomotive difficulties, mental retardation, dyslexia etc. In the present paper we show the advantages of using multimedia software to develop mental skills in handicapped people and deal with the special needs of handicapped children. For the rehabilitation of stroke patients we have developed a computer-controlled method, which enables - contrary to methods used internationally - not only the establishment of a diagnosis, but also measurement of therapy effectiveness: 1) it enables us to produce a database of patients, which contains not only their personal data but also test results, their drawings and audio recordings, 2) it is in itself an intensive therapeutic test and contains tutorial programs. We are currently collecting test results. We have also developed some virtual worlds for treating phobias: a virtual balcony and a ten-story building with an external glass elevator as well as an internal glass elevator in the virtual Atrium Hyatt hotel. We have developed a virtual environment for treating claustrophobia too: a closed lift and a room where the walls can move. For specific phobias (fear of travelling) we have modelled the underground railway system in Budapest. For autistic children, we have developed virtual shopping software too. In this paper we present the advantages of virtual reality in the investigation, evaluation and treatment of perception, behaviour and neuropsychological disorders.

Data-driven model reference control of MIMO vertical tank systems with model-free VRFT and Q-Learning.

PubMed

Radac, Mircea-Bogdan; Precup, Radu-Emil; Roman, Raul-Cristian

2018-02-01

This paper proposes a combined Virtual Reference Feedback Tuning-Q-learning model-free control approach, which tunes nonlinear static state feedback controllers to achieve output model reference tracking in an optimal control framework. The novel iterative Batch Fitted Q-learning strategy uses two neural networks to represent the value function (critic) and the controller (actor), and it is referred to as a mixed Virtual Reference Feedback Tuning-Batch Fitted Q-learning approach. Learning convergence of the Q-learning schemes generally depends, among other settings, on the efficient exploration of the state-action space. Handcrafting test signals for efficient exploration is difficult even for input-output stable unknown processes. Virtual Reference Feedback Tuning can ensure an initial stabilizing controller to be learned from few input-output data and it can be next used to collect substantially more input-state data in a controlled mode, in a constrained environment, by compensating the process dynamics. This data is used to learn significantly superior nonlinear state feedback neural networks controllers for model reference tracking, using the proposed Batch Fitted Q-learning iterative tuning strategy, motivating the original combination of the two techniques. The mixed Virtual Reference Feedback Tuning-Batch Fitted Q-learning approach is experimentally validated for water level control of a multi input-multi output nonlinear constrained coupled two-tank system. Discussions on the observed control behavior are offered. Copyright © 2018 ISA. Published by Elsevier Ltd. All rights reserved.

The Effect of Balance Training on Postural Control in Patients with Parkinson's Disease Using a Virtual Rehabilitation System.

PubMed

Albiol-Pérez, Sergio; Gil-Gómez, José-Antonio; Muñoz-Tomás, María-Teresa; Gil-Gómez, Hermenegildo; Vial-Escolano, Raquel; Lozano-Quilis, José-Antonio

2017-03-23

Parkinson's disease (PD) is a progressive neurodegenerative disorder characterized by motor clinical alterations among others. Postural problems have serious consequences for patients, not only limiting their daily life but also increasing some risks, like the risk of fall. Inadequate postural control and postural instability is a major problem in PD patients. A Virtual Motor Rehabilitation System (VMR) has been tested in patients with PD in the intervention period. Our purpose was to analyze the evolution of the spatial postural control during the intervention period, to see if there are any changes caused precisely by this intervention. Ten people with PD carried out 15 virtual rehabilitation sessions. We tested a groundbreaking system based on Virtual Motor Rehabilitation in two periods of time (baseline evaluation and final evaluation). In the training sessions, the participants performed a customizable treatment using a low-cost system, the Active Balance Rehabilitation system (ABAR). We stored the pressure performed by the participants every five hundredths of a second, and we analyzed the patients' pressure when they maintained their body on the left, on the right, and in the center in sitting position. Our system was able to measure postural control in every patient in each of the virtual rehabilitation sessions. There are no significant differences in the performance of postural control in any of the positions evaluated throughout the sessions. Moreover, the results show a trend to an improvement in all positions. This improvement is especially remarkable in the left/right positions, which are the most important positions in order to avoid problems such as the risk of fall. With regard to the suitability of the ABAR system, we have found outstanding results in enjoyment, success, clarity, and helpfulness. Although PD is a progressive neurodegenerative disorder, the results demonstrate that patients with PD maintain or even improve their postural control in all positions. We think that the main factor influencing these results is that patients use more of their available cognitive processing to improve their postural control. The ABAR system allows us to make this assumption because the system requires the continuous attention of patients, promoting cognitive processing.

Virtual multiple errands test (VMET): a virtual reality-based tool to detect early executive functions deficit in Parkinson’s disease

PubMed Central

Cipresso, Pietro; Albani, Giovanni; Serino, Silvia; Pedroli, Elisa; Pallavicini, Federica; Mauro, Alessandro; Riva, Giuseppe

2014-01-01

Introduction: Several recent studies have pointed out that early impairment of executive functions (EFs) in Parkinson’s Disease (PD) may be a crucial marker to detect patients at risk for developing dementia. The main objective of this study was to compare the performances of PD patients with mild cognitive impairment (PD-MCI) with PD patients with normal cognition (PD-NC) and a control group (CG) using a traditional assessment of EFs and the Virtual Multiple Errands Test (VMET), a virtual reality (VR)-based tool. In order to understand which subcomponents of EFs are early impaired, this experimental study aimed to investigate specifically which instrument best discriminates among these three groups. Materials and methods: The study included three groups of 15 individuals each (for a total of 45 participants): 15 PD-NC; 15 PD-MCI, and 15 cognitively healthy individuals (CG). To assess the global neuropsychological functioning and the EFs, several tests (including the Mini Mental State Examination (MMSE), Clock Drawing Test, and Tower of London test) were administered to the participants. The VMET was used for a more ecologically valid neuropsychological evaluation of EFs. Results: Findings revealed significant differences in the VMET scores between the PD-NC patients vs. the controls. In particular, patients made more errors in the tasks of the VMET, and showed a poorer ability to use effective strategies to complete the tasks. This VMET result seems to be more sensitive in the early detection of executive deficits because these two groups did not differ in the traditional assessment of EFs (neuropsychological battery). Conclusion: This study offers initial evidence that a more ecologically valid evaluation of EFs is more likely to lead to detection of subtle executive deficits. PMID:25538578

Virtual multiple errands test (VMET): a virtual reality-based tool to detect early executive functions deficit in Parkinson's disease.

PubMed

Cipresso, Pietro; Albani, Giovanni; Serino, Silvia; Pedroli, Elisa; Pallavicini, Federica; Mauro, Alessandro; Riva, Giuseppe

2014-01-01

Several recent studies have pointed out that early impairment of executive functions (EFs) in Parkinson's Disease (PD) may be a crucial marker to detect patients at risk for developing dementia. The main objective of this study was to compare the performances of PD patients with mild cognitive impairment (PD-MCI) with PD patients with normal cognition (PD-NC) and a control group (CG) using a traditional assessment of EFs and the Virtual Multiple Errands Test (VMET), a virtual reality (VR)-based tool. In order to understand which subcomponents of EFs are early impaired, this experimental study aimed to investigate specifically which instrument best discriminates among these three groups. The study included three groups of 15 individuals each (for a total of 45 participants): 15 PD-NC; 15 PD-MCI, and 15 cognitively healthy individuals (CG). To assess the global neuropsychological functioning and the EFs, several tests (including the Mini Mental State Examination (MMSE), Clock Drawing Test, and Tower of London test) were administered to the participants. The VMET was used for a more ecologically valid neuropsychological evaluation of EFs. Findings revealed significant differences in the VMET scores between the PD-NC patients vs. the controls. In particular, patients made more errors in the tasks of the VMET, and showed a poorer ability to use effective strategies to complete the tasks. This VMET result seems to be more sensitive in the early detection of executive deficits because these two groups did not differ in the traditional assessment of EFs (neuropsychological battery). This study offers initial evidence that a more ecologically valid evaluation of EFs is more likely to lead to detection of subtle executive deficits.

The Integrated Virtual Environment Rehabilitation Treadmill System

PubMed Central

Feasel, Jeff; Whitton, Mary C.; Kassler, Laura; Brooks, Frederick P.; Lewek, Michael D.

2015-01-01

Slow gait speed and interlimb asymmetry are prevalent in a variety of disorders. Current approaches to locomotor retraining emphasize the need for appropriate feedback during intensive, task-specific practice. This paper describes the design and feasibility testing of the integrated virtual environment rehabilitation treadmill (IVERT) system intended to provide real-time, intuitive feedback regarding gait speed and asymmetry during training. The IVERT system integrates an instrumented, split-belt treadmill with a front-projection, immersive virtual environment. The novel adaptive control system uses only ground reaction force data from the treadmill to continuously update the speeds of the two treadmill belts independently, as well as to control the speed and heading in the virtual environment in real time. Feedback regarding gait asymmetry is presented 1) visually as walking a curved trajectory through the virtual environment and 2) proprioceptively in the form of different belt speeds on the split-belt treadmill. A feasibility study involving five individuals with asymmetric gait found that these individuals could effectively control the speed of locomotion and perceive gait asymmetry during the training session. Although minimal changes in overground gait symmetry were observed immediately following a single training session, further studies should be done to determine the IVERT’s potential as a tool for rehabilitation of asymmetric gait by providing patients with congruent visual and proprioceptive feedback. PMID:21652279

An innovative training program based on virtual reality and treadmill: effects on gait of persons with multiple sclerosis.

PubMed

Peruzzi, Agnese; Zarbo, Ignazio Roberto; Cereatti, Andrea; Della Croce, Ugo; Mirelman, Anat

2017-07-01

In this single blind randomized controlled trial, we examined the effect of a virtual reality-based training on gait of people with multiple sclerosis. Twenty-five individuals with multiple sclerosis with mild to moderate disability were randomly assigned to either the control group (n = 11) or the experimental group (n = 14). The subjects in the control group received treadmill training. Subjects in the experimental group received virtual reality based treadmill training. Clinical measures and gait parameters were evaluated. Subjects in both the groups significantly improved the walking endurance and speed, cadence and stride length, lower limb joint ranges of motion and powers, during single and dual task gait. Moreover, subjects in the experimental group also improved balance, as indicated by the results of the clinical motor tests (p < 0.05). Between-group comparisons revealed that the experimental group improved significantly more than control group in hip range of motion and hip generated power at terminal stance at post-training. Our results support the perceived benefits of training programs that incorporate virtual reality to improve gait measures in individuals with multiple sclerosis. Implication of rehabilitation Gait deficits are common in multiple sclerosis (85%) and worsen during dual task activities. Intensive and progressive treadmill training, with and without virtual reality, is effective on dual task gait in persons with multiple sclerosis. Virtual reality-based treadmill training requiring obstacle negotiation increases the range of motion and the power generated at the hip, consequently allowing longer stride length and, consequently, higher gait speed.

Protecting Files Hosted on Virtual Machines With Out-of-Guest Access Control

DTIC Science & Technology

2017-12-01

analyzes the design and methodology of the implemented mechanism, while Chapter 4 explains the test methodology, test cases, and performance testing ...SACL, we verify that the user or group accessing the file has sufficient permissions. If that is correct, the callback function returns control to...ferify. In the first section, we validate our design of ferify. Next, we explain the tests we performed to verify that ferify has the results we expected

Virtual hybrid test control of sinuous crack

NASA Astrophysics Data System (ADS)

Jailin, Clément; Carpiuc, Andreea; Kazymyrenko, Kyrylo; Poncelet, Martin; Leclerc, Hugo; Hild, François; Roux, Stéphane

2017-05-01

The present study aims at proposing a new generation of experimental protocol for analysing crack propagation in quasi brittle materials. The boundary conditions are controlled in real-time to conform to a predefined crack path. Servo-control is achieved through a full-field measurement technique to determine the pre-set fracture path and a simple predictor model based on linear elastic fracture mechanics to prescribe the boundary conditions on the fly so that the actual crack path follows at best the predefined trajectory. The final goal is to identify, for instance, non-local damage models involving internal lengths. The validation of this novel procedure is performed via a virtual test-case based on an enriched damage model with an internal length scale, a prior chosen sinusoidal crack path and a concrete sample. Notwithstanding the fact that the predictor model selected for monitoring the test is a highly simplified picture of the targeted constitutive law, the proposed protocol exhibits a much improved sensitivity to the sought parameters such as internal lengths as assessed from the comparison with other available experimental tests.

Intelligent launch and range operations virtual testbed (ILRO-VTB)

NASA Astrophysics Data System (ADS)

Bardina, Jorge; Rajkumar, Thirumalainambi

2003-09-01

Intelligent Launch and Range Operations Virtual Test Bed (ILRO-VTB) is a real-time web-based command and control, communication, and intelligent simulation environment of ground-vehicle, launch and range operation activities. ILRO-VTB consists of a variety of simulation models combined with commercial and indigenous software developments (NASA Ames). It creates a hybrid software/hardware environment suitable for testing various integrated control system components of launch and range. The dynamic interactions of the integrated simulated control systems are not well understood. Insight into such systems can only be achieved through simulation/emulation. For that reason, NASA has established a VTB where we can learn the actual control and dynamics of designs for future space programs, including testing and performance evaluation. The current implementation of the VTB simulates the operations of a sub-orbital vehicle of mission, control, ground-vehicle engineering, launch and range operations. The present development of the test bed simulates the operations of Space Shuttle Vehicle (SSV) at NASA Kennedy Space Center. The test bed supports a wide variety of shuttle missions with ancillary modeling capabilities like weather forecasting, lightning tracker, toxic gas dispersion model, debris dispersion model, telemetry, trajectory modeling, ground operations, payload models and etc. To achieve the simulations, all models are linked using Common Object Request Broker Architecture (CORBA). The test bed provides opportunities for government, universities, researchers and industries to do a real time of shuttle launch in cyber space.

Modeling infectious diseases dissemination through online role-playing games.

PubMed

Balicer, Ran D

2007-03-01

As mathematical modeling of infectious diseases becomes increasingly important for developing public health policies, a novel platform for such studies might be considered. Millions of people worldwide play interactive online role-playing games, forming complex and rich networks among their virtual characters. An unexpected outbreak of an infective communicable disease (unplanned by the game creators) recently occurred in this virtual world. This outbreak holds surprising similarities to real-world epidemics. It is possible that these virtual environments could serve as a platform for studying the dissemination of infectious diseases, and as a testing ground for novel interventions to control emerging communicable diseases.

Development of and feedback on a fully automated virtual reality system for online training in weight management skills.

PubMed

Thomas, J Graham; Spitalnick, Josh S; Hadley, Wendy; Bond, Dale S; Wing, Rena R

2015-01-01

Virtual reality (VR) technology can provide a safe environment for observing, learning, and practicing use of behavioral weight management skills, which could be particularly useful in enhancing minimal contact online weight management programs. The Experience Success (ES) project developed a system for creating and deploying VR scenarios for online weight management skills training. Virtual environments populated with virtual actors allow users to experiment with implementing behavioral skills via a PC-based point and click interface. A culturally sensitive virtual coach guides the experience, including planning for real-world skill use. Thirty-seven overweight/obese women provided feedback on a test scenario focused on social eating situations. They reported that the scenario gave them greater skills, confidence, and commitment for controlling eating in social situations. © 2014 Diabetes Technology Society.

Development of and Feedback on a Fully Automated Virtual Reality System for Online Training in Weight Management Skills

PubMed Central

Spitalnick, Josh S.; Hadley, Wendy; Bond, Dale S.; Wing, Rena R.

2014-01-01

Virtual reality (VR) technology can provide a safe environment for observing, learning, and practicing use of behavioral weight management skills, which could be particularly useful in enhancing minimal contact online weight management programs. The Experience Success (ES) project developed a system for creating and deploying VR scenarios for online weight management skills training. Virtual environments populated with virtual actors allow users to experiment with implementing behavioral skills via a PC-based point and click interface. A culturally sensitive virtual coach guides the experience, including planning for real-world skill use. Thirty-seven overweight/obese women provided feedback on a test scenario focused on social eating situations. They reported that the scenario gave them greater skills, confidence, and commitment for controlling eating in social situations. PMID:25367014

COMPLEX CONDITIONAL CONTROL BY PIGEONS IN A CONTINUOUS VIRTUAL ENVIRONMENT

PubMed Central

Qadri, Muhammad A. J.; Reid, Sean; Cook, Robert G.

2016-01-01

We tested two pigeons in a continuously streaming digital environment. Using animation software that constantly presented a dynamic, three-dimensional (3D) environment, the animals were tested with a conditional object identification task. The correct object at a given time depended on the virtual context currently streaming in front of the pigeon. Pigeons were required to accurately peck correct target objects in the environment for food reward, while suppressing any pecks to intermixed distractor objects which delayed the next object’s presentation. Experiment 1 established that the pigeons’ discrimination of two objects could be controlled by the surface material of the digital terrain. Experiment 2 established that the pigeons’ discrimination of four objects could be conjunctively controlled by both the surface material and topography of the streaming environment. These experiments indicate that pigeons can simultaneously process and use at least two context cues from a streaming environment to control their identification behavior of passing objects. These results add to the promise of testing interactive digital environments with animals to advance our understanding of cognition and behavior. PMID:26781058

Harnessing Neuroplasticity to Promote Rehabilitation: CI Therapy for TBI

DTIC Science & Technology

2016-10-01

scheduled plus 33 to be enrolled, because we assume that the proportion of withdrawals will be the same as experienced to date, i.e., 24%. This plan will...period? Victor Mark, Investigator Interactive Immersive Virtual Reality Walking for SCI Neuropathic Pain (Trost) 0.24 calendar months Kim Cerise...Direct Costs: $149,999 This project designs and test an immersive virtual reality treatment method to control neuropathic pain following traumatic spinal

The Power of the Virtual Ideal Self in Weight Control: Weight-Reduced Avatars Can Enhance the Tendency to Delay Gratification and Regulate Dietary Practices.

PubMed

Kuo, Hsu-Chan; Lee, Chun-Chia; Chiou, Wen-Bin

2016-02-01

The tendency to discount larger future benefits in favor of smaller immediate gains (i.e., temporal discounting) is relevant to the issue of obesity. Successful weight loss requires individuals to sacrifice immediate culinary pleasures in favor of future health gains. Based on the notion that increasing the vividness of one's future self may mitigate temporal discounting and promote the ability to delay gratification, we examined whether viewing one's weight-reduced self (i.e., the ideal self) in a virtual environment can decrease temporal discounting and lead to better regulation of dietary practices. Seventy-six undergraduates who had reported an intention to lose weight were recruited to participate in a laboratory experiment and were randomly assigned to interact with either the weight-reduced self (experimental condition) or the present self (control condition) by looking into a dressing mirror in a virtual fitting room. A temporal-discounting task and a taste test were subsequently administered. Results showed that, compared with control participants, participants who viewed their weight-reduced avatars ate less ice cream in a taste test and were more likely to choose a sugar-free drink as a reward. The discounting rate mediated the association between the avatar manipulation and the amount of ice cream eaten in the subsequent taste test. Overall, our findings suggest that a computer-generated image of one's weight-reduced self may assist in resisting impulses that promote immediate gratification over delayed benefits. This research provides a new approach for controlling impulsive behavior such as dietary regulation and weight control.

[Neuropsychological evaluation of the executive functions by means of virtual reality].

PubMed

Climent-Martínez, Gema; Luna-Lario, Pilar; Bombín-González, Igor; Cifuentes-Rodríguez, Alicia; Tirapu-Ustárroz, Javier; Díaz-Orueta, Unai

2014-05-16

Executive functions include a wide range of self regulatory functions that allow control, organization and coordination of other cognitive functions, emotional responses and behaviours. The traditional approach to evaluate these functions, by means of paper and pencil neuropsychological tests, shows a greater than expected performance within the normal range for patients whose daily life difficulties would predict an inferior performance. These discrepancies suggest that classical neuropsychological tests may not adequately reproduce the complexity and dynamic nature of real life situations. Latest developments in the field of virtual reality offer interesting options for the neuropsychological assessment of many cognitive processes. Virtual reality reproduces three-dimensional environments with which the patient interacts in a dynamic way, with a sense of immersion in the environment similar to the presence and exposure to a real environment. Furthermore, the presentation of these stimuli, as well as distractors and other variables, may be controlled in a systematic way. Moreover, more consistent and precise answers may be obtained, and an in-depth analysis of them is possible. The present review shows current problems in neuropsychological evaluation of executive functions and latest advances in the consecution of higher preciseness and validity of the evaluation by means of new technologies and virtual reality, with special mention to some developments performed in Spain.

Comparing the influence of physical and virtual manipulatives in the context of the Physics by Inquiry curriculum: The case of undergraduate students' conceptual understanding of heat and temperature

NASA Astrophysics Data System (ADS)

Zacharia, Zacharias C.; Constantinou, Constantinos P.

2008-04-01

We compare the effect of experimenting with physical or virtual manipulatives on undergraduate students' conceptual understanding of heat and temperature. A pre-post comparison study design was used to replicate all aspects of a guided inquiry classroom except the mode in which students performed their experiments. This study is the first on physical and virtual manipulative experimentation in physics in which the curriculum, method of instruction, and resource capabilities were explicitly controlled. The participants were 68 undergraduates in an introductory course and were randomly assigned to an experimental or a control group. Conceptual tests were administered to both groups to assess students' understanding before, during, and after instruction. The result indicates that both modes of experimentation are equally effective in enhancing students' conceptual understanding. This result is discussed in the context of an ongoing debate on the relative importance of virtual and real laboratory work in physics education.

Application of a Virtual Reactivity Feedback Control Loop in Non-Nuclear Testing of a Fast Spectrum Reactor

NASA Technical Reports Server (NTRS)

Bragg-Sitton, Shannon M.; Forsbacka, Matthew

2004-01-01

For a compact, fast-spectrum reactor, reactivity feedback is dominated by core deformation at elevated temperature. Given the use of accurate deformation measurement techniques, it is possible to simulate nuclear feedback in non-nuclear electrically heated reactor tests. Implementation of simulated reactivity feedback in response to measured deflection is being tested at the NASA Marshall Space Flight Center Early Flight Fission Test Facility (EFF-TF). During tests of the SAFE-100 reactor prototype, core deflection was monitored using a high resolution camera. "virtual" reactivity feedback was accomplished by applying the results of Monte Carlo calculations (MCNPX) to core deflection measurements; the computational analysis was used to establish the reactivity worth of van'ous core deformations. The power delivered to the SAFE-100 prototype was then dusted accordingly via kinetics calculations, The work presented in this paper will demonstrate virtual reactivity feedback as core power was increased from 1 kilowatt(sub t), to 10 kilowatts(sub t), held approximately constant at 10 kilowatts (sub t), and then allowed to decrease based on the negative thermal reactivity coefficient.

Intensive virtual reality-based training for upper limb motor function in chronic stroke: a feasibility study using a single case experimental design and fMRI.

PubMed

Schuster-Amft, Corina; Henneke, Andrea; Hartog-Keisker, Birgit; Holper, Lisa; Siekierka, Ewa; Chevrier, Edith; Pyk, Pawel; Kollias, Spyros; Kiper, Daniel; Eng, Kynan

2015-01-01

To evaluate feasibility and neurophysiological changes after virtual reality (VR)-based training of upper limb (UL) movements. Single-case A-B-A-design with two male stroke patients (P1:67 y and 50 y, 3.5 and 3 y after onset) with UL motor impairments, 45-min therapy sessions 5×/week over 4 weeks. Patients facing screen, used bimanual data gloves to control virtual arms. Three applications trained bimanual reaching, grasping, hand opening. Assessments during 2-week baseline, weekly during intervention, at 3-month follow-up (FU): Goal Attainment Scale (GAS), Chedoke Arm and Hand Activity Inventory (CAHAI), Chedoke-McMaster Stroke Assessment (CMSA), Extended Barthel Index (EBI), Motor Activity Log (MAL). Functional magnetic resonance imaging scans (FMRI) before, immediately after treatment and at FU. P1 executed 5478 grasps (paretic arm). Improvements in CAHAI (+4) were maintained at FU. GAS changed to +1 post-test and +2 at FU. P2 executed 9835 grasps (paretic arm). CAHAI improvements (+13) were maintained at FU. GAS scores changed to -1 post-test and +1 at FU. MAL scores changed from 3.7 at pre-test to 5.5 post-test and 3.3 at FU. The VR-based intervention was feasible, safe, and intense. Adjustable application settings maintained training challenge and patient motivation. ADL-relevant UL functional improvements persisted at FU and were related to changed cortical activation patterns. Implications for Rehabilitation YouGrabber trains uni- and bimanual upper motor function. Its application is feasible, safe, and intense. The control of the virtual arms can be done in three main ways: (a) normal (b) virtual mirror therapy, or (c) virtual following. The mirroring feature provides an illusion of affected limb movements during the period when the affected upper limb (UL) is resting. The YouGrabber training led to ADL-relevant UL functional improvements that were still assessable 12 weeks after intervention finalization and were related to changed cortical activation patterns.

Assessment of wheelchair driving performance in a virtual reality-based simulator

PubMed Central

Mahajan, Harshal P.; Dicianno, Brad E.; Cooper, Rory A.; Ding, Dan

2013-01-01

Objective To develop a virtual reality (VR)-based simulator that can assist clinicians in performing standardized wheelchair driving assessments. Design A completely within-subjects repeated measures design. Methods Participants drove their wheelchairs along a virtual driving circuit modeled after the Power Mobility Road Test (PMRT) and in a hallway with decreasing width. The virtual simulator was displayed on computer screen and VR screens and participants interacted with it using a set of instrumented rollers and a wheelchair joystick. Driving performances of participants were estimated and compared using quantitative metrics from the simulator. Qualitative ratings from two experienced clinicians were used to estimate intra- and inter-rater reliability. Results Ten regular wheelchair users (seven men, three women; mean age ± SD, 39.5 ± 15.39 years) participated. The virtual PMRT scores from the two clinicians show high inter-rater reliability (78–90%) and high intra-rater reliability (71–90%) for all test conditions. More research is required to explore user preferences and effectiveness of the two control methods (rollers and mathematical model) and the display screens. Conclusions The virtual driving simulator seems to be a promising tool for wheelchair driving assessment that clinicians can use to supplement their real-world evaluations. PMID:23820148

Ant-Based Cyber Defense (also known as

DOE Office of Scientific and Technical Information (OSTI.GOV)

Glenn Fink, PNNL

2015-09-29

ABCD is a four-level hierarchy with human supervisors at the top, a top-level agent called a Sergeant controlling each enclave, Sentinel agents located at each monitored host, and mobile Sensor agents that swarm through the enclaves to detect cyber malice and misconfigurations. The code comprises four parts: (1) the core agent framework, (2) the user interface and visualization, (3) test-range software to create a network of virtual machines including a simulated Internet and user and host activity emulation scripts, and (4) a test harness to allow the safe running of adversarial code within the framework of monitored virtual machines.

Deception and Shopping Behavior Among Current Cigarette Smokers: A Web-Based, Randomized Virtual Shopping Experiment.

PubMed

Dutra, Lauren McCarl; Nonnemaker, James; Taylor, Nathaniel; Kim, Annice E

2018-06-29

Virtual stores can be used to identify influences on consumer shopping behavior. Deception is one technique that may be used to attempt to increase the realism of virtual stores. The objective of the experiment was to test whether the purchasing behavior of participants in a virtual shopping task varied based on whether they were told that they would receive the products they selected in a virtual convenience store (a form of deception) or not. We recruited a US national sample of 402 adult current smokers by email from an online panel of survey participants. They completed a fully automated randomized virtual shopping experiment with a US $15 or US $20 budget in a Web-based virtual convenience store. We told a random half of participants that they would receive the products they chose in the virtual store or the cash equivalent (intervention condition), and the other random half simply to conduct a shopping task (control condition). We tested for differences in demographics, tobacco use behaviors, and in-store purchases (outcome variable, assessed by questionnaire) by experimental condition. The characteristics of the participants (398/402, 99.0% with complete data) were comparable across conditions except that the intervention group contained slightly more female participants (103/197, 52.3%) than the control group (84/201, 41.8%; P=.04). We did not find any other significant differences in any other demographic variables or tobacco use, or in virtual store shopping behaviors, including purchasing any tobacco (P=.44); purchasing cigarettes (P=.16), e-cigarettes (P=.54), cigars (P=.98), or smokeless tobacco (P=.72); amount spent overall (P=.63) or on tobacco (P=.66); percentage of budget spent overall (P=.84) or on tobacco (P=.74); number of total items (P=.64) and tobacco items purchased (P=.54); or total time spent in the store (P=.07). We found that telling participants that they will receive the products they select in a virtual store did not influence their purchases. This finding suggests that deception may not affect consumer behavior and, as a result, may not be necessary in virtual shopping experiments. ©Lauren McCarl Dutra, James Nonnemaker, Nathaniel Taylor, Annice E Kim. Originally published in JMIR Research Protocols (http://www.researchprotocols.org), 29.06.2018.

Examination of the gamma equilibrium point hypothesis when applied to single degree of freedom movements performed with different inertial loads.

PubMed

Bellomo, A; Inbar, G

1997-01-01

One of the theories of human motor control is the gamma Equilibrium Point Hypothesis. It is an attractive theory since it offers an easy control scheme where the planned trajectory shifts monotionically from an initial to a final equilibrium state. The feasibility of this model was tested by reconstructing the virtual trajectory and the stiffness profiles for movements performed with different inertial loads and examining them. Three types of movements were tested: passive movements, targeted movements, and repetitive movements. Each of the movements was performed with five different inertial loads. Plausible virtual trajectories and stiffness profiles were reconstructed based on the gamma Equilibrium Point Hypothesis for the three different types of movements performed with different inertial loads. However, the simple control strategy supported by the model, where the planned trajectory shifts monotonically from an initial to a final equilibrium state, could not be supported for targeted movements performed with added inertial load. To test the feasibility of the model further we must examine the probability that the human motor control system would choose a trajectory more complicated than the actual trajectory to control.

Design of an immersive simulator for assisted power wheelchair driving.

PubMed

Devigne, Louise; Babel, Marie; Nouviale, Florian; Narayanan, Vishnu K; Pasteau, Francois; Gallien, Philippe

2017-07-01

Driving a power wheelchair is a difficult and complex visual-cognitive task. As a result, some people with visual and/or cognitive disabilities cannot access the benefits of a power wheelchair because their impairments prevent them from driving safely. In order to improve their access to mobility, we have previously designed a semi-autonomous assistive wheelchair system which progressively corrects the trajectory as the user manually drives the wheelchair and smoothly avoids obstacles. Developing and testing such systems for wheelchair driving assistance requires a significant amount of material resources and clinician time. With Virtual Reality technology, prototypes can be developed and tested in a risk-free and highly flexible Virtual Environment before equipping and testing a physical prototype. Additionally, users can "virtually" test and train more easily during the development process. In this paper, we introduce a power wheelchair driving simulator allowing the user to navigate with a standard wheelchair in an immersive 3D Virtual Environment. The simulation framework is designed to be flexible so that we can use different control inputs. In order to validate the framework, we first performed tests on the simulator with able-bodied participants during which the user's Quality of Experience (QoE) was assessed through a set of questionnaires. Results show that the simulator is a promising tool for future works as it generates a good sense of presence and requires rather low cognitive effort from users.

Open core control software for surgical robots

PubMed Central

Kozuka, Hiroaki; Kim, Hyung Wook; Takesue, Naoyuki; Vladimirov, B.; Sakaguchi, Masamichi; Tokuda, Junichi; Hata, Nobuhiko; Chinzei, Kiyoyuki; Fujimoto, Hideo

2010-01-01

Object In these days, patients and doctors in operation room are surrounded by many medical devices as resulting from recent advancement of medical technology. However, these cutting-edge medical devices are working independently and not collaborating with each other, even though the collaborations between these devices such as navigation systems and medical imaging devices are becoming very important for accomplishing complex surgical tasks (such as a tumor removal procedure while checking the tumor location in neurosurgery). On the other hand, several surgical robots have been commercialized, and are becoming common. However, these surgical robots are not open for collaborations with external medical devices in these days. A cutting-edge “intelligent surgical robot” will be possible in collaborating with surgical robots, various kinds of sensors, navigation system and so on. On the other hand, most of the academic software developments for surgical robots are “home-made” in their research institutions and not open to the public. Therefore, open source control software for surgical robots can be beneficial in this field. From these perspectives, we developed Open Core Control software for surgical robots to overcome these challenges. Materials and methods In general, control softwares have hardware dependencies based on actuators, sensors and various kinds of internal devices. Therefore, these control softwares cannot be used on different types of robots without modifications. However, the structure of the Open Core Control software can be reused for various types of robots by abstracting hardware dependent parts. In addition, network connectivity is crucial for collaboration between advanced medical devices. The OpenIGTLink is adopted in Interface class which plays a role to communicate with external medical devices. At the same time, it is essential to maintain the stable operation within the asynchronous data transactions through network. In the Open Core Control software, several techniques for this purpose were introduced. Virtual fixture is well known technique as a “force guide” for supporting operators to perform precise manipulation by using a master–slave robot. The virtual fixture for precise and safety surgery was implemented on the system to demonstrate an idea of high-level collaboration between a surgical robot and a navigation system. The extension of virtual fixture is not a part of the Open Core Control system, however, the function such as virtual fixture cannot be realized without a tight collaboration between cutting-edge medical devices. By using the virtual fixture, operators can pre-define an accessible area on the navigation system, and the area information can be transferred to the robot. In this manner, the surgical console generates the reflection force when the operator tries to get out from the pre-defined accessible area during surgery. Results The Open Core Control software was implemented on a surgical master–slave robot and stable operation was observed in a motion test. The tip of the surgical robot was displayed on a navigation system by connecting the surgical robot with a 3D position sensor through the OpenIGTLink. The accessible area was pre-defined before the operation, and the virtual fixture was displayed as a “force guide” on the surgical console. In addition, the system showed stable performance in a duration test with network disturbance. Conclusion In this paper, a design of the Open Core Control software for surgical robots and the implementation of virtual fixture were described. The Open Core Control software was implemented on a surgical robot system and showed stable performance in high-level collaboration works. The Open Core Control software is developed to be a widely used platform of surgical robots. Safety issues are essential for control software of these complex medical devices. It is important to follow the global specifications such as a FDA requirement “General Principles of Software Validation” or IEC62304. For following these regulations, it is important to develop a self-test environment. Therefore, a test environment is now under development to test various interference in operation room such as a noise of electric knife by considering safety and test environment regulations such as ISO13849 and IEC60508. The Open Core Control software is currently being developed software in open-source manner and available on the Internet. A communization of software interface is becoming a major trend in this field. Based on this perspective, the Open Core Control software can be expected to bring contributions in this field. PMID:20033506

Fully Three-Dimensional Virtual-Reality System

NASA Technical Reports Server (NTRS)

Beckman, Brian C.

1994-01-01

Proposed virtual-reality system presents visual displays to simulate free flight in three-dimensional space. System, virtual space pod, is testbed for control and navigation schemes. Unlike most virtual-reality systems, virtual space pod would not depend for orientation on ground plane, which hinders free flight in three dimensions. Space pod provides comfortable seating, convenient controls, and dynamic virtual-space images for virtual traveler. Controls include buttons plus joysticks with six degrees of freedom.

Virtual manufacturing work cell for engineering

NASA Astrophysics Data System (ADS)

Watanabe, Hideo; Ohashi, Kazushi; Takahashi, Nobuyuki; Kato, Kiyotaka; Fujita, Satoru

1997-12-01

The life cycles of products have been getting shorter. To meet this rapid turnover, manufacturing systems must be frequently changed as well. In engineering to develop manufacturing systems, there are several tasks such as process planning, layout design, programming, and final testing using actual machines. This development of manufacturing systems takes a long time and is expensive. To aid the above engineering process, we have developed the virtual manufacturing workcell (VMW). This paper describes a concept of VMW and design method through computer aided manufacturing engineering using VMW (CAME-VMW) related to the above engineering tasks. The VMW has all design data, and realizes a behavior of equipment and devices using a simulator. The simulator has logical and physical functionality. The one simulates a sequence control and the other simulates motion control, shape movement in 3D space. The simulator can execute the same control software made for actual machines. Therefore we can verify the behavior precisely before the manufacturing workcell will be constructed. The VMW creates engineering work space for several engineers and offers debugging tools such as virtual equipment and virtual controllers. We applied this VMW to development of a transfer workcell for vaporization machine in actual manufacturing system to produce plasma display panel (PDP) workcell and confirmed its effectiveness.

Cyber-Physical System Security With Deceptive Virtual Hosts for Industrial Control Networks

DOE PAGES

Vollmer, Todd; Manic, Milos

2014-05-01

A challenge facing industrial control network administrators is protecting the typically large number of connected assets for which they are responsible. These cyber devices may be tightly coupled with the physical processes they control and human induced failures risk dire real-world consequences. Dynamic virtual honeypots are effective tools for observing and attracting network intruder activity. This paper presents a design and implementation for self-configuring honeypots that passively examine control system network traffic and actively adapt to the observed environment. In contrast to prior work in the field, six tools were analyzed for suitability of network entity information gathering. Ettercap, anmore » established network security tool not commonly used in this capacity, outperformed the other tools and was chosen for implementation. Utilizing Ettercap XML output, a novel four-step algorithm was developed for autonomous creation and update of a Honeyd configuration. This algorithm was tested on an existing small campus grid and sensor network by execution of a collaborative usage scenario. Automatically created virtual hosts were deployed in concert with an anomaly behavior (AB) system in an attack scenario. Virtual hosts were automatically configured with unique emulated network stack behaviors for 92% of the targeted devices. The AB system alerted on 100% of the monitored emulated devices.« less

Assessment of radiation awareness training in immersive virtual environments

NASA Astrophysics Data System (ADS)

Whisker, Vaughn E., III

The prospect of new nuclear power plant orders in the near future and the graying of the current workforce create a need to train new personnel faster and better. Immersive virtual reality (VR) may offer a solution to the training challenge. VR technology presented in a CAVE Automatic Virtual Environment (CAVE) provides a high-fidelity, one-to-one scale environment where areas of the power plant can be recreated and virtual radiation environments can be simulated, making it possible to safely expose workers to virtual radiation in the context of the actual work environment. The use of virtual reality for training is supported by many educational theories; constructivism and discovery learning, in particular. Educational theory describes the importance of matching the training to the task. Plant access training and radiation worker training, common forms of training in the nuclear industry, rely on computer-based training methods in most cases, which effectively transfer declarative knowledge, but are poor at transferring skills. If an activity were to be added, the training would provide personnel with the opportunity to develop skills and apply their knowledge so they could be more effective when working in the radiation environment. An experiment was developed to test immersive virtual reality's suitability for training radiation awareness. Using a mixed methodology of quantitative and qualitative measures, the subjects' performances before and after training were assessed. First, subjects completed a pre-test to measure their knowledge prior to completing any training. Next they completed unsupervised computer-based training, which consisted of a PowerPoint presentation and a PDF document. After completing a brief orientation activity in the virtual environment, one group of participants received supplemental radiation awareness training in a simulated radiation environment presented in the CAVE, while a second group, the control group, moved directly to the assessment phase of the experiment. The CAVE supplied an activity-based training environment where learners were able to use a virtual survey meter to explore the properties of radiation sources and the effects of time and distance on radiation exposure. Once the training stage had ended, the subjects completed an assessment activity where they were asked to complete four tasks in a simulated radiation environment in the CAVE, which was designed to provide a more authentic assessment than simply testing understanding using a quiz. After the practicum, the subjects completed a post-test. Survey information was also collected to assist the researcher with interpretation of the collected data. Response to the training was measured by completion time, radiation exposure received, successful completion of the four tasks in the practicum, and scores on the post-test. These results were combined to create a radiation awareness score. In addition, observational data was collected as the subjects completed the tasks. The radiation awareness scores of the control group and the group that received supplemental training in the virtual environment were compared. T-tests showed that the effect of the supplemental training was not significant; however, calculation of the effect size showed a small-to-medium effect of the training. The CAVE group received significantly less radiation exposure during the assessment activity, and they completed the activities on an average of one minute faster. These results indicate that the training was effective, primarily for instilling radiation sensitivity. Observational data collected during the assessment supports this conclusion. The training environment provided by the immersive virtual reality recreated a radiation environment where learners could apply knowledge they had been taught by computer-based training. Activity-based training has been shown to be a more effective way to transfer skills because of the similarity between the training environment and the application environment. Virtual reality enables the training environment to look and feel like the application environment. Because of this, radiation awareness training in an immersive virtual environment should be considered by the nuclear industry, which is supported by the results of this experiment.

Molecular Rift: Virtual Reality for Drug Designers.

PubMed

Norrby, Magnus; Grebner, Christoph; Eriksson, Joakim; Boström, Jonas

2015-11-23

Recent advances in interaction design have created new ways to use computers. One example is the ability to create enhanced 3D environments that simulate physical presence in the real world--a virtual reality. This is relevant to drug discovery since molecular models are frequently used to obtain deeper understandings of, say, ligand-protein complexes. We have developed a tool (Molecular Rift), which creates a virtual reality environment steered with hand movements. Oculus Rift, a head-mounted display, is used to create the virtual settings. The program is controlled by gesture-recognition, using the gaming sensor MS Kinect v2, eliminating the need for standard input devices. The Open Babel toolkit was integrated to provide access to powerful cheminformatics functions. Molecular Rift was developed with a focus on usability, including iterative test-group evaluations. We conclude with reflections on virtual reality's future capabilities in chemistry and education. Molecular Rift is open source and can be downloaded from GitHub.

Intercepting real and simulated falling objects: what is the difference?

PubMed

Baurès, Robin; Benguigui, Nicolas; Amorim, Michel-Ange; Hecht, Heiko

2009-10-30

The use of virtual reality is nowadays common in many studies in the field of human perception and movement control, particularly in interceptive actions. However, the ecological validity of the simulation is often taken for granted without having been formally established. If participants were to perceive the real situation and its virtual equivalent in a different fashion, the generalization of the results obtained in virtual reality to real life would be highly questionable. We tested the ecological validity of virtual reality in this context by comparing the timing of interceptive actions based upon actually falling objects and their simulated counterparts. The results show very limited differences as a function of whether participants were confronted with a real ball or a simulation thereof. And when present, such differences were limited to the first trial only. This result validates the use of virtual reality when studying interceptive actions of accelerated stimuli.

Virtual Reality for Research in Social Neuroscience

PubMed Central

Parsons, Thomas D.; Gaggioli, Andrea; Riva, Giuseppe

2017-01-01

The emergence of social neuroscience has significantly advanced our understanding of the relationship that exists between social processes and their neurobiological underpinnings. Social neuroscience research often involves the use of simple and static stimuli lacking many of the potentially important aspects of real world activities and social interactions. Whilst this research has merit, there is a growing interest in the presentation of dynamic stimuli in a manner that allows researchers to assess the integrative processes carried out by perceivers over time. Herein, we discuss the potential of virtual reality for enhancing ecological validity while maintaining experimental control in social neuroscience research. Virtual reality is a technology that allows for the creation of fully interactive, three-dimensional computerized models of social situations that can be fully controlled by the experimenter. Furthermore, the introduction of interactive virtual characters—either driven by a human or by a computer—allows the researcher to test, in a systematic and independent manner, the effects of various social cues. We first introduce key technical features and concepts related to virtual reality. Next, we discuss the potential of this technology for enhancing social neuroscience protocols, drawing on illustrative experiments from the literature. PMID:28420150

Virtual Reality for Research in Social Neuroscience.

PubMed

Parsons, Thomas D; Gaggioli, Andrea; Riva, Giuseppe

2017-04-16

The emergence of social neuroscience has significantly advanced our understanding of the relationship that exists between social processes and their neurobiological underpinnings. Social neuroscience research often involves the use of simple and static stimuli lacking many of the potentially important aspects of real world activities and social interactions. Whilst this research has merit, there is a growing interest in the presentation of dynamic stimuli in a manner that allows researchers to assess the integrative processes carried out by perceivers over time. Herein, we discuss the potential of virtual reality for enhancing ecological validity while maintaining experimental control in social neuroscience research. Virtual reality is a technology that allows for the creation of fully interactive, three-dimensional computerized models of social situations that can be fully controlled by the experimenter. Furthermore, the introduction of interactive virtual characters-either driven by a human or by a computer-allows the researcher to test, in a systematic and independent manner, the effects of various social cues. We first introduce key technical features and concepts related to virtual reality. Next, we discuss the potential of this technology for enhancing social neuroscience protocols, drawing on illustrative experiments from the literature.

How do people with persecutory delusions evaluate threat in a controlled social environment? A qualitative study using virtual reality.

PubMed

Fornells-Ambrojo, Miriam; Freeman, Daniel; Slater, Mel; Swapp, David; Antley, Angus; Barker, Chris

2015-01-01

Environmental factors have been associated with psychosis but there is little qualitative research looking at how the ongoing interaction between individual and environment maintains psychotic symptoms. The current study investigates how people with persecutory delusions interpret events in a virtual neutral social environment using qualitative methodology. 20 participants with persecutory delusions and 20 controls entered a virtual underground train containing neutral characters. Under these circumstances, people with persecutory delusions reported similar levels of paranoia as non-clinical participants. The transcripts of a post-virtual reality interview of the first 10 participants in each group were analysed. Thematic analyses of interviews focusing on the decision making process associated with attributing intentions of computer-generated characters revealed 11 themes grouped in 3 main categories (evidence in favour of paranoid appraisals, evidence against paranoid appraisals, other behaviour). People with current persecutory delusions are able to use a range of similar strategies to healthy volunteers when making judgements about potential threat in a neutral environment that does not elicit anxiety, but they are less likely than controls to engage in active hypothesis-testing and instead favour experiencing "affect" as evidence of persecutory intention.

The effect of implementing cognitive load theory-based design principles in virtual reality simulation training of surgical skills: a randomized controlled trial.

PubMed

Andersen, Steven Arild Wuyts; Mikkelsen, Peter Trier; Konge, Lars; Cayé-Thomasen, Per; Sørensen, Mads Sølvsten

2016-01-01

Cognitive overload can inhibit learning, and cognitive load theory-based instructional design principles can be used to optimize learning situations. This study aims to investigate the effect of implementing cognitive load theory-based design principles in virtual reality simulation training of mastoidectomy. Eighteen novice medical students received 1 h of self-directed virtual reality simulation training of the mastoidectomy procedure randomized for standard instructions (control) or cognitive load theory-based instructions with a worked example followed by a problem completion exercise (intervention). Participants then completed two post-training virtual procedures for assessment and comparison. Cognitive load during the post-training procedures was estimated by reaction time testing on an integrated secondary task. Final-product analysis by two blinded expert raters was used to assess the virtual mastoidectomy performances. Participants in the intervention group had a significantly increased cognitive load during the post-training procedures compared with the control group (52 vs. 41 %, p  = 0.02). This was also reflected in the final-product performance: the intervention group had a significantly lower final-product score than the control group (13.0 vs. 15.4, p  < 0.005). Initial instruction using worked examples followed by a problem completion exercise did not reduce the cognitive load or improve the performance of the following procedures in novices. Increased cognitive load when part tasks needed to be integrated in the post-training procedures could be a possible explanation for this. Other instructional designs and methods are needed to lower the cognitive load and improve the performance in virtual reality surgical simulation training of novices.

Virtual reality and neuropsychological assessment: The reliability of a virtual kitchen to assess daily-life activities in victims of traumatic brain injury.

PubMed

Besnard, Jeremy; Richard, Paul; Banville, Frederic; Nolin, Pierre; Aubin, Ghislaine; Le Gall, Didier; Richard, Isabelle; Allain, Phillippe

2016-01-01

Traumatic brain injury (TBI) causes impairments affecting instrumental activities of daily living (IADL). However, few studies have considered virtual reality as an ecologically valid tool for the assessment of IADL in patients who have sustained a TBI. The main objective of the present study was to examine the use of the Nonimmersive Virtual Coffee Task (NI-VCT) for IADL assessment in patients with TBI. We analyzed the performance of 19 adults suffering from TBI and 19 healthy controls (HCs) in the real and virtual tasks of making coffee with a coffee machine, as well as in global IQ and executive functions. Patients performed worse than HCs on both real and virtual tasks and on all tests of executive functions. Correlation analyses revealed that NI-VCT scores were related to scores on the real task. Moreover, regression analyses demonstrated that performance on NI-VCT matched real-task performance. Our results support the idea that the virtual kitchen is a valid tool for IADL assessment in patients who have sustained a TBI.

Comparing two methods of education (virtual versus traditional) on learning of Iranian dental students: a post-test only design study

PubMed Central

2014-01-01

Background The importance of using technologies such as e-learning in different disciplines is discussed in the literature. Researchers have measured the effectiveness of e-learning in a number of fields. Considering the lack of research on the effectiveness of online learning in dental education particularly in Iran, the advantages of these learning methods and the positive university atmosphere regarding the use of online learning. This study, therefore, aims to compare the effects of two methods of teaching (virtual versus traditional) on student learning. Methods This post-test only design study approached 40, fifth year dental students of Shiraz University of Medical Sciences. From this group, 35 students agreed to participate. These students were randomly allocated into two groups, experimental (virtual learning) and comparison (traditional learning). To ensure similarity between groups, we compared GPAs of all participants by the Mann–Whitney U test (P > 0.05). The experimental group received a virtual learning environment courseware package specifically designed for this study, whereas the control group received the same module structured in a traditional lecture form. The virtual learning environment consisted of online and offline materials. Two identical valid, reliable post-tests that consisted of 40 multiple choice questions (MCQs) and 4 essay questions were administered immediately (15 min) after the last session and two months later to assess for knowledge retention. Data were analyzed by SPSS version 20. Results A comparison of the mean knowledge score of both groups showed that virtual learning was more effective than traditional learning (effect size = 0.69). Conclusion The newly designed virtual learning package is feasible and will result in more effective learning in comparison with lecture-based training. However further studies are needed to generalize the findings of this study. PMID:24597923

Effects of substituting a portion of standard physiotherapy time with virtual reality games among community-dwelling stroke survivors

PubMed Central

2013-01-01

Background Evidence indicates that the continuation of therapy among community-dwelling stroke survivors improves physical function. Community rehabilitation programmes often face limitations in terms of resources. It is imperative to include new motivational interventions to encourage some level of non-clinician management. The aim of this study was to determine whether there were any changes in physical function and activities of daily living when substituting a portion of the standard physiotherapy time with virtual reality games among community-dwelling stroke survivors. Methods In this controlled trial, the experimental group received 30 minutes of virtual reality balance games in addition to 90 minutes of standard physiotherapy. The control group continued with their two hours of routine standard physiotherapy. Both groups received 12 therapy sessions: two-hour sessions twice per week for six continuous weeks. Changes in physical function, activities of daily living and balance ability were assessed using the Timed Up and Go test, 30-second Sit to Stand test, Timed Ten-Metre Walk test, Six-Minute Walk test and the Barthel Index, and static balance was assessed using a probalance board. Results Twenty-eight participants completed post-intervention assessments. The results showed a significant within-subject effect on the Timed Up and Go test: F (1, 26) = 5.83, p = 0.02; and the 30-second Sit to Stand test; F (1, 26) = 13.50, p = 0.001. The between-subject effect was not significant (p > 0.05) for any of the outcome measurements. Conclusion Substituting a portion of the standard physiotherapy time with virtual reality games was equally effective in maintaining physical function outcomes and activities of daily living among community-dwelling stroke survivors. Trial Registration Australia and New Zealand Clinical Trials Register, ACTRN12613000478718 PMID:24330250

Near-Infrared Spectroscopy-Based Frontal Lobe Neurofeedback Integrated in Virtual Reality Modulates Brain and Behavior in Highly Impulsive Adults.

PubMed

Hudak, Justin; Blume, Friederike; Dresler, Thomas; Haeussinger, Florian B; Renner, Tobias J; Fallgatter, Andreas J; Gawrilow, Caterina; Ehlis, Ann-Christine

2017-01-01

Based on neurofeedback (NF) training as a neurocognitive treatment in attention-deficit/hyperactivity disorder (ADHD), we designed a randomized, controlled functional near-infrared spectroscopy (fNIRS) NF intervention embedded in an immersive virtual reality classroom in which participants learned to control overhead lighting with their dorsolateral prefrontal brain activation. We tested the efficacy of the intervention on healthy adults displaying high impulsivity as a sub-clinical population sharing common features with ADHD. Twenty participants, 10 in an experimental and 10 in a shoulder muscle-based electromyography control group, underwent eight training sessions across 2 weeks. Training was bookended by a pre- and post-test including go/no-go, n-back, and stop-signal tasks (SST). Results indicated a significant reduction in commission errors on the no-go task with a simultaneous increase in prefrontal oxygenated hemoglobin concentration for the experimental group, but not for the control group. Furthermore, the ability of the subjects to gain control over the feedback parameter correlated strongly with the reduction in commission errors for the experimental, but not for the control group, indicating the potential importance of learning feedback control in moderating behavioral outcomes. In addition, participants of the fNIRS group showed a reduction in reaction time variability on the SST. Results indicate a clear effect of our NF intervention in reducing impulsive behavior possibly via a strengthening of frontal lobe functioning. Virtual reality additions to conventional NF may be one way to improve the ecological validity and symptom-relevance of the training situation, hence positively affecting transfer of acquired skills to real life.

Advanced Maintenance Simulation by Means of Hand-Based Haptic Interfaces

NASA Astrophysics Data System (ADS)

Nappi, Michele; Paolino, Luca; Ricciardi, Stefano; Sebillo, Monica; Vitiello, Giuliana

Aerospace industry has been involved in virtual simulation for design and testing since the birth of virtual reality. Today this industry is showing a growing interest in the development of haptic-based maintenance training applications, which represent the most advanced way to simulate maintenance and repair tasks within a virtual environment by means of a visual-haptic approach. The goal is to allow the trainee to experiment the service procedures not only as a workflow reproduced at a visual level but also in terms of the kinaesthetic feedback involved with the manipulation of tools and components. This study, conducted in collaboration with aerospace industry specialists, is aimed to the development of an immersive virtual capable of immerging the trainees into a virtual environment where mechanics and technicians can perform maintenance simulation or training tasks by directly manipulating 3D virtual models of aircraft parts while perceiving force feedback through the haptic interface. The proposed system is based on ViRstperson, a virtual reality engine under development at the Italian Center for Aerospace Research (CIRA) to support engineering and technical activities such as design-time maintenance procedure validation, and maintenance training. This engine has been extended to support haptic-based interaction, enabling a more complete level of interaction, also in terms of impedance control, and thus fostering the development of haptic knowledge in the user. The user’s “sense of touch” within the immersive virtual environment is simulated through an Immersion CyberForce® hand-based force-feedback device. Preliminary testing of the proposed system seems encouraging.

LAMOST CCD camera-control system based on RTS2

NASA Astrophysics Data System (ADS)

Tian, Yuan; Wang, Zheng; Li, Jian; Cao, Zi-Huang; Dai, Wei; Wei, Shou-Lin; Zhao, Yong-Heng

2018-05-01

The Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) is the largest existing spectroscopic survey telescope, having 32 scientific charge-coupled-device (CCD) cameras for acquiring spectra. Stability and automation of the camera-control software are essential, but cannot be provided by the existing system. The Remote Telescope System 2nd Version (RTS2) is an open-source and automatic observatory-control system. However, all previous RTS2 applications were developed for small telescopes. This paper focuses on implementation of an RTS2-based camera-control system for the 32 CCDs of LAMOST. A virtual camera module inherited from the RTS2 camera module is built as a device component working on the RTS2 framework. To improve the controllability and robustness, a virtualized layer is designed using the master-slave software paradigm, and the virtual camera module is mapped to the 32 real cameras of LAMOST. The new system is deployed in the actual environment and experimentally tested. Finally, multiple observations are conducted using this new RTS2-framework-based control system. The new camera-control system is found to satisfy the requirements for automatic camera control in LAMOST. This is the first time that RTS2 has been applied to a large telescope, and provides a referential solution for full RTS2 introduction to the LAMOST observatory control system.

Virtual reality conditioned place preference using monetary reward

PubMed Central

Childs, Emma; Astur, Robert S.; de Wit, Harriet

2017-01-01

Computerized tasks based on conditioned place preference (CPP) methodology offer the opportunity to study learning mechanisms involved in conditioned reward in humans. In this study, we examined acquisition and extinction of a CPP for virtual environments associated with monetary reward ($). Healthy men and women (N=57) completed a computerized CPP task in which they controlled an avatar within a virtual environment. On day 1, subjects completed 6 conditioning trials in which one room was paired with high $ and another with low $. Acquisition of place conditioning was assessed by measuring the time spent in each room during an exploration test of the virtual environments and using self-reported ratings of room liking and preference. Twenty-four hours later, retention and extinction of CPP were assessed during 4 successive exploration tests of the virtual environments. Participants exhibited a place preference for (spent significantly more time in) the virtual room paired with high $ over the one paired with low $ (p=0.015). They also reported that they preferred the high $ room (p<0.001) and liked it significantly more than the low $ room (p<0.001). However, these preferences were short-lived: 24h later subjects did not exhibit a behavioral or subjective preference for the high $ room. These findings show that individuals exhibit transient behavioral and subjective preferences for a virtual environment paired with monetary reward. Variations on this task may be useful to study mechanisms and brain substrates involved in conditioned reward and to examine the influence of drugs upon appetitive conditioning. PMID:28108321

Virtual Reality Simulation of the International Space Welding Experiment

NASA Technical Reports Server (NTRS)

Phillips, James A.

1996-01-01

Virtual Reality (VR) is a set of breakthrough technologies that allow a human being to enter and fully experience a 3-dimensional, computer simulated environment. A true virtual reality experience meets three criteria: (1) It involves 3-dimensional computer graphics; (2) It includes real-time feedback and response to user actions; and (3) It must provide a sense of immersion. Good examples of a virtual reality simulator are the flight simulators used by all branches of the military to train pilots for combat in high performance jet fighters. The fidelity of such simulators is extremely high -- but so is the price tag, typically millions of dollars. Virtual reality teaching and training methods are manifestly effective, and we have therefore implemented a VR trainer for the International Space Welding Experiment. My role in the development of the ISWE trainer consisted of the following: (1) created texture-mapped models of the ISWE's rotating sample drum, technology block, tool stowage assembly, sliding foot restraint, and control panel; (2) developed C code for control panel button selection and rotation of the sample drum; (3) In collaboration with Tim Clark (Antares Virtual Reality Systems), developed a serial interface box for the PC and the SGI Indigo so that external control devices, similar to ones actually used on the ISWE, could be used to control virtual objects in the ISWE simulation; (4) In collaboration with Peter Wang (SFFP) and Mark Blasingame (Boeing), established the interference characteristics of the VIM 1000 head-mounted-display and tested software filters to correct the problem; (5) In collaboration with Peter Wang and Mark Blasingame, established software and procedures for interfacing the VPL DataGlove and the Polhemus 6DOF position sensors to the SGI Indigo serial ports. The majority of the ISWE modeling effort was conducted on a PC-based VR Workstation, described below.

Clinical usefulness of the virtual reality-based postural control training on the gait ability in patients with stroke.

PubMed

Park, Yu-Hyung; Lee, Chi-Ho; Lee, Byoung-Hee

2013-01-01

This study is a single blind randomized controlled trial to determine the effect of virtual reality-based postural control training on the gait ability in patients with chronic stroke. Sixteen subjects were randomly assigned to either experimental group (VR, n= 8) or control group (CPT, n= 8). Subjects in both groups received conventional physical therapy for 60 min per day, five days per week during a period of four weeks. Subjects in the VR group received additional augmented reality-based training for 30 min per day, three days per week during a period of four weeks. The subjects were evaluated one week before and after participating in a four week training and follow-up at one month post-training. Data derived from the gait analyses included spatiotemporal gait parameters, 10 meters walking test (10 mWT). In the gait parameters, subjects in the VR group showed significant improvement, except for cadence at post-training and follow-up within the experimental group. However, no obvious significant improvement was observed within the control group. In between group comparisons, the experimental group (VR group) showed significantly greater improvement only in stride length compared with the control group (P< 0.05), however, no significant difference was observed in other gait parameters. In conclusion, we demonstrate significant improvement in gait ability in chronic stroke patients who received virtual reality based postural control training. These findings suggest that virtual reality (VR) postural control training using real-time information may be a useful approach for enhancement of gait ability in patients with chronic stroke.

Virtual reality skills training for health care professionals in alcohol screening and brief intervention.

PubMed

Fleming, Michael; Olsen, Dale; Stathes, Hilary; Boteler, Laura; Grossberg, Paul; Pfeifer, Judie; Schiro, Stephanie; Banning, Jane; Skochelak, Susan

2009-01-01

Educating physicians and other health care professionals about the identification and treatment of patients who drink more than recommended limits is an ongoing challenge. An educational randomized controlled trial was conducted to test the ability of a stand-alone training simulation to improve the clinical skills of health care professionals in alcohol screening and intervention. The "virtual reality simulation" combined video, voice recognition, and nonbranching logic to create an interactive environment that allowed trainees to encounter complex social cues and realistic interpersonal exchanges. The simulation included 707 questions and statements and 1207 simulated patient responses. A sample of 102 health care professionals (10 physicians; 30 physician assistants or nurse practitioners; 36 medical students; 26 pharmacy, physican assistant, or nurse practitioner students) were randomly assigned to a no training group (n = 51) or a computer-based virtual reality intervention (n = 51). Professionals in both groups had similar pretest standardized patient alcohol screening skill scores: 53.2 (experimental) vs 54.4 (controls), 52.2 vs 53.7 alcohol brief intervention skills, and 42.9 vs 43.5 alcohol referral skills. After repeated practice with the simulation there were significant increases in the scores of the experimental group at 6 months after randomization compared with the control group for the screening (67.7 vs 58.1; P < .001) and brief intervention (58.3 vs 51.6; P < .04) scenarios. The technology tested in this trial is the first virtual reality simulation to demonstrate an increase in the alcohol screening and brief intervention skills of health care professionals.

Operational Overview for UAS Integration in the NAS Project Flight Test Series 3

NASA Technical Reports Server (NTRS)

Valkov, Steffi B.; Sternberg, Daniel; Marston, Michael

2017-01-01

The National Aeronautics and Space Administration Unmanned Aircraft Systems Integration in the National Airspace System Project has conducted a series of flight tests intended to support the reduction of barriers that prevent unmanned aircraft from flying without the required waivers from the Federal Aviation Administration. The 2015 Flight Test Series 3, supported two separate test configurations. The first configuration investigated the timing of Detect and Avoid alerting thresholds using a radar equipped unmanned vehicle and multiple live intruders flown at varying encounter geometries. The second configuration included a surrogate unmanned vehicle (flown from a ground control station, with a safety pilot on board) flying a mission in a virtual air traffic control airspace sector using research pilot displays and Detect and Avoid advisories to maintain separation from live and virtual aircraft. The test was conducted over an eight-week span within the R-2508 Special Use Airspace. Over 200 encounters were flown for the first configuration, and although the second configuration was cancelled after three data collection flights, Flight Test 3 proved to be invaluable for the purposes of planning, managing, and execution of this type of integrated flight test.

Navigation experience and mental representations of the environment: do pilots build better cognitive maps?

PubMed

Sutton, Jennifer E; Buset, Melanie; Keller, Mikayla

2014-01-01

A number of careers involve tasks that place demands on spatial cognition, but it is still unclear how and whether skills acquired in such applied experiences transfer to other spatial tasks. The current study investigated the association between pilot training and the ability to form a mental survey representation, or cognitive map, of a novel, ground-based, virtual environment. Undergraduate students who were engaged in general aviation pilot training and controls matched to the pilots on gender and video game usage freely explored a virtual town. Subsequently, participants performed a direction estimation task that tested the accuracy of their cognitive map representation of the town. In addition, participants completed the Object Perspective Test and rated their spatial abilities. Pilots were significantly more accurate than controls at estimating directions but did not differ from controls on the Object Perspective Test. Locations in the town were visited at a similar rate by the two groups, indicating that controls' relatively lower accuracy was not due to failure to fully explore the town. Pilots' superior performance is likely due to better online cognitive processing during exploration, suggesting the spatial updating they engage in during flight transfers to a non-aviation context.

Navigation Experience and Mental Representations of the Environment: Do Pilots Build Better Cognitive Maps?

PubMed Central

Sutton, Jennifer E.; Buset, Melanie; Keller, Mikayla

2014-01-01

A number of careers involve tasks that place demands on spatial cognition, but it is still unclear how and whether skills acquired in such applied experiences transfer to other spatial tasks. The current study investigated the association between pilot training and the ability to form a mental survey representation, or cognitive map, of a novel, ground-based, virtual environment. Undergraduate students who were engaged in general aviation pilot training and controls matched to the pilots on gender and video game usage freely explored a virtual town. Subsequently, participants performed a direction estimation task that tested the accuracy of their cognitive map representation of the town. In addition, participants completed the Object Perspective Test and rated their spatial abilities. Pilots were significantly more accurate than controls at estimating directions but did not differ from controls on the Object Perspective Test. Locations in the town were visited at a similar rate by the two groups, indicating that controls' relatively lower accuracy was not due to failure to fully explore the town. Pilots' superior performance is likely due to better online cognitive processing during exploration, suggesting the spatial updating they engage in during flight transfers to a non-aviation context. PMID:24603608

Virtual-reality-based attention assessment of ADHD: ClinicaVR: Classroom-CPT versus a traditional continuous performance test.

PubMed

Neguț, Alexandra; Jurma, Anda Maria; David, Daniel

2017-08-01

Virtual-reality-based assessment may be a good alternative to classical or computerized neuropsychological assessment due to increased ecological validity. ClinicaVR: Classroom-CPT (VC) is a neuropsychological test embedded in virtual reality that is designed to assess attention deficits in children with attention deficit hyperactivity disorder (ADHD) or other conditions associated with impaired attention. The present study aimed to (1) investigate the diagnostic validity of VC in comparison to a traditional continuous performance test (CPT), (2) explore the task difficulty of VC, (3) address the effect of distractors on the performance of ADHD participants and typically-developing (TD) controls, and (4) compare the two measures on cognitive absorption. A total of 33 children diagnosed with ADHD and 42 TD children, aged between 7 and 13 years, participated in the study and were tested with a traditional CPT or with VC, along with several cognitive measures and an adapted version of the Cognitive Absorption Scale. A mixed multivariate analysis of covariance (MANCOVA) revealed that the children with ADHD performed worse on correct responses had more commissions and omissions errors than the TD children, as well as slower target reaction times . The results showed significant differences between performance in the virtual environment and the traditional computerized one, with longer reaction times in virtual reality. The data analysis highlighted the negative influence of auditory distractors on attention performance in the case of the children with ADHD, but not for the TD children. Finally, the two measures did not differ on the cognitive absorption perceived by the children.

Delay-based virtual congestion control in multi-tenant datacenters

NASA Astrophysics Data System (ADS)

Liu, Yuxin; Zhu, Danhong; Zhang, Dong

2018-03-01

With the evolution of cloud computing and virtualization, the congestion control of virtual datacenters has become the basic issue for multi-tenant datacenters transmission. Regarding to the friendly conflict of heterogeneous congestion control among multi-tenant, this paper proposes a delay-based virtual congestion control, which translates the multi-tenant heterogeneous congestion control into delay-based feedback uniformly by setting the hypervisor translation layer, modifying three-way handshake of explicit feedback and packet loss feedback and throttling receive window. The simulation results show that the delay-based virtual congestion control can effectively solve the unfairness of heterogeneous feedback congestion control algorithms.

Effectiveness of the Virtual Reality System Toyra on Upper Limb Function in People with Tetraplegia: A Pilot Randomized Clinical Trial.

PubMed

Dimbwadyo-Terrer, I; Gil-Agudo, A; Segura-Fragoso, A; de los Reyes-Guzmán, A; Trincado-Alonso, F; Piazza, S; Polonio-López, B

2016-01-01

The aim of this study was to investigate the effects of a virtual reality program combined with conventional therapy in upper limb function in people with tetraplegia and to provide data about patients' satisfaction with the virtual reality system. Thirty-one people with subacute complete cervical tetraplegia participated in the study. Experimental group received 15 sessions with Toyra(®) virtual reality system for 5 weeks, 30 minutes/day, 3 days/week in addition to conventional therapy, while control group only received conventional therapy. All patients were assessed at baseline, after intervention, and at three-month follow-up with a battery of clinical, functional, and satisfaction scales. Control group showed significant improvements in the manual muscle test (p = 0,043, partial η (2) = 0,22) in the follow-up evaluation. Both groups demonstrated clinical, but nonsignificant, changes to their arm function in 4 of the 5 scales used. All patients showed a high level of satisfaction with the virtual reality system. This study showed that virtual reality added to conventional therapy produces similar results in upper limb function compared to only conventional therapy. Moreover, the gaming aspects incorporated in conventional rehabilitation appear to produce high motivation during execution of the assigned tasks. This trial is registered with EudraCT number 2015-002157-35.

Effectiveness of the Virtual Reality System Toyra on Upper Limb Function in People with Tetraplegia: A Pilot Randomized Clinical Trial

PubMed Central

Dimbwadyo-Terrer, I.; Gil-Agudo, A.; Segura-Fragoso, A.; de los Reyes-Guzmán, A.; Trincado-Alonso, F.; Piazza, S.; Polonio-López, B.

2016-01-01

The aim of this study was to investigate the effects of a virtual reality program combined with conventional therapy in upper limb function in people with tetraplegia and to provide data about patients' satisfaction with the virtual reality system. Thirty-one people with subacute complete cervical tetraplegia participated in the study. Experimental group received 15 sessions with Toyra® virtual reality system for 5 weeks, 30 minutes/day, 3 days/week in addition to conventional therapy, while control group only received conventional therapy. All patients were assessed at baseline, after intervention, and at three-month follow-up with a battery of clinical, functional, and satisfaction scales. Control group showed significant improvements in the manual muscle test (p = 0,043, partial η 2 = 0,22) in the follow-up evaluation. Both groups demonstrated clinical, but nonsignificant, changes to their arm function in 4 of the 5 scales used. All patients showed a high level of satisfaction with the virtual reality system. This study showed that virtual reality added to conventional therapy produces similar results in upper limb function compared to only conventional therapy. Moreover, the gaming aspects incorporated in conventional rehabilitation appear to produce high motivation during execution of the assigned tasks. This trial is registered with EudraCT number 2015-002157-35. PMID:26885511

Virtual and remote robotic laboratory using EJS, MATLAB and LabVIEW.

PubMed

Chaos, Dictino; Chacón, Jesús; Lopez-Orozco, Jose Antonio; Dormido, Sebastián

2013-02-21

This paper describes the design and implementation of a virtual and remote laboratory based on Easy Java Simulations (EJS) and LabVIEW. The main application of this laboratory is to improve the study of sensors in Mobile Robotics, dealing with the problems that arise on the real world experiments. This laboratory allows the user to work from their homes, tele-operating a real robot that takes measurements from its sensors in order to obtain a map of its environment. In addition, the application allows interacting with a robot simulation (virtual laboratory) or with a real robot (remote laboratory), with the same simple and intuitive graphical user interface in EJS. Thus, students can develop signal processing and control algorithms for the robot in simulation and then deploy them on the real robot for testing purposes. Practical examples of application of the laboratory on the inter-University Master of Systems Engineering and Automatic Control are presented.

Virtual and Remote Robotic Laboratory Using EJS, MATLAB and Lab VIEW

PubMed Central

Chaos, Dictino; Chacón, Jesús; Lopez-Orozco, Jose Antonio; Dormido, Sebastián

2013-01-01

This paper describes the design and implementation of a virtual and remote laboratory based on Easy Java Simulations (EJS) and LabVIEW. The main application of this laboratory is to improve the study of sensors in Mobile Robotics, dealing with the problems that arise on the real world experiments. This laboratory allows the user to work from their homes, tele-operating a real robot that takes measurements from its sensors in order to obtain a map of its environment. In addition, the application allows interacting with a robot simulation (virtual laboratory) or with a real robot (remote laboratory), with the same simple and intuitive graphical user interface in EJS. Thus, students can develop signal processing and control algorithms for the robot in simulation and then deploy them on the real robot for testing purposes. Practical examples of application of the laboratory on the inter-University Master of Systems Engineering and Automatic Control are presented. PMID:23429578

Virtual reality exercise on a home-based phase III cardiac rehabilitation program, effect on executive function, quality of life and depression, anxiety and stress: a randomized controlled trial.

PubMed

Vieira, Ágata; Melo, Cristina; Machado, Jorge; Gabriel, Joaquim

2018-02-01

To analyse the effect of a six-month home-based phase III cardiac rehabilitation (CR) specific exercise program, performed in a virtual reality (Kinect) or conventional (booklet) environment, on executive function, quality of life and depression, anxiety and stress of subjects with coronary artery disease. A randomized controlled trial was conducted with subjects, who had completed phase II, randomly assigned to intervention group 1 (IG1), whose program encompassed the use of Kinect (n = 11); or intervention group 2 (IG2), a paper booklet (n = 11); or a control group (CG), only subjected to the usual care (n = 11). The three groups received education on cardiovascular risk factors. The assessed parameters, at baseline (M0), 3 (M1) and 6 months (M2), were executive function, control and integration in the implementation of an adequate behaviour in relation to a certain objective, specifically the ability to switch information (Trail Making Test), working memory (Verbal Digit Span test), and selective attention and conflict resolution ability (Stroop test), quality of life (MacNew questionnaire) and depression, anxiety and stress (Depression, Anxiety and Stress Scale 21). Descriptive and inferential statistical measures were used, significance level was set at .05. The IG1 revealed significant improvements, in the selective attention and conflict resolution ability, in comparison with the CG in the variable difference M0 - M2 (p = .021) and in comparison with the IG2 in the variable difference M1 - M2 and M0 - M2 (p = .001 and p = .002, respectively). No significant differences were found in the quality of life, and depression, anxiety and stress. The virtual reality format had improved selective attention and conflict resolution ability, revealing the potential of CR, specifically with virtual reality exercise, on executive function. Implications for Rehabilitation In cardiac rehabilitation, especially in phase III, it is important to develop and to present alternative strategies, as virtual reality using the Kinect in a home context. Taking into account the relationship between the improvement of the executive function with physical exercise, it is relevant to access the impact of a cardiac rehabilitation program on the executive function. Enhancing the value of the phase III of cardiac rehabilitation.

Virtual Sensor for Kinematic Estimation of Flexible Links in Parallel Robots

PubMed Central

Cabanes, Itziar; Mancisidor, Aitziber; Pinto, Charles

2017-01-01

The control of flexible link parallel manipulators is still an open area of research, endpoint trajectory tracking being one of the main challenges in this type of robot. The flexibility and deformations of the limbs make the estimation of the Tool Centre Point (TCP) position a challenging one. Authors have proposed different approaches to estimate this deformation and deduce the location of the TCP. However, most of these approaches require expensive measurement systems or the use of high computational cost integration methods. This work presents a novel approach based on a virtual sensor which can not only precisely estimate the deformation of the flexible links in control applications (less than 2% error), but also its derivatives (less than 6% error in velocity and 13% error in acceleration) according to simulation results. The validity of the proposed Virtual Sensor is tested in a Delta Robot, where the position of the TCP is estimated based on the Virtual Sensor measurements with less than a 0.03% of error in comparison with the flexible approach developed in ADAMS Multibody Software. PMID:28832510

Seeing and identifying with a virtual body decreases pain perception.

PubMed

Hänsel, Alexander; Lenggenhager, Bigna; von Känel, Roland; Curatolo, Michele; Blanke, Olaf

2011-09-01

Pain and the conscious mind (or the self) are experienced in our body. Both are intimately linked to the subjective quality of conscious experience. Here, we used virtual reality technology and visuo-tactile conflicts in healthy subjects to test whether experimentally induced changes of bodily self-consciousness (self-location; self-identification) lead to changes in pain perception. We found that visuo-tactile stroking of a virtual body but not of a control object led to increased pressure pain thresholds and self-location. This increase was not modulated by the synchrony of stroking as predicted based on earlier work. This differed for self-identification where we found as predicted that synchrony of stroking increased self-identification with the virtual body (but not a control object), and positively correlated with an increase in pain thresholds. We discuss the functional mechanisms of self-identification, self-location, and the visual perception of human bodies with respect to pain perception. Copyright © 2011 European Federation of International Association for the Study of Pain Chapters. Published by Elsevier Ltd. All rights reserved.

Integration of the virtual 3D model of a control system with the virtual controller

NASA Astrophysics Data System (ADS)

Herbuś, K.; Ociepka, P.

2015-11-01

Nowadays the design process includes simulation analysis of different components of a constructed object. It involves the need for integration of different virtual object to simulate the whole investigated technical system. The paper presents the issues related to the integration of a virtual 3D model of a chosen control system of with a virtual controller. The goal of integration is to verify the operation of an adopted object of in accordance with the established control program. The object of the simulation work is the drive system of a tunneling machine for trenchless work. In the first stage of work was created an interactive visualization of functioning of the 3D virtual model of a tunneling machine. For this purpose, the software of the VR (Virtual Reality) class was applied. In the elaborated interactive application were created adequate procedures allowing controlling the drive system of a translatory motion, a rotary motion and the drive system of a manipulator. Additionally was created the procedure of turning on and off the output crushing head, mounted on the last element of the manipulator. In the elaborated interactive application have been established procedures for receiving input data from external software, on the basis of the dynamic data exchange (DDE), which allow controlling actuators of particular control systems of the considered machine. In the next stage of work, the program on a virtual driver, in the ladder diagram (LD) language, was created. The control program was developed on the basis of the adopted work cycle of the tunneling machine. The element integrating the virtual model of the tunneling machine for trenchless work with the virtual controller is the application written in a high level language (Visual Basic). In the developed application was created procedures responsible for collecting data from the running, in a simulation mode, virtual controller and transferring them to the interactive application, in which is verified the operation of the adopted research object. The carried out work allowed foot the integration of the virtual model of the control system of the tunneling machine with the virtual controller, enabling the verification of its operation.

Flight Testing the X-36: The Test Pilots Perspective

NASA Technical Reports Server (NTRS)

Walker, Laurence A.

1997-01-01

The X-36 is a 28% scale, remotely piloted research aircraft, designed to demonstrate tailless fighter agility. Powered by a modified Williams International F-112 jet engine, the X-36 uses thrust vectoring and a fly-by-wire control system. Although too small for an onboard pilot, a full-sized remote cockpit was designed to virtually place the test pilot into the aircraft using a variety of innovative techniques. To date, 22 flights have been flown, successfully completing the second phase of testing. Handling qualities have been matching predictions; the test operation is flown similarly to that for full sized manned aircraft. All takeoffs, test maneuvers and landings are flown by the test pilot, affording a greater degree of flexibility and the ability to handle the inevitable unknowns which may occur during highly experimental test programs. The cockpit environment, cues, and display techniques used in this effort have proven to enhance the 'virtual' test pilot's awareness and have helped ensure a successful RPV test program.

Use of virtual reality intervention to improve reaction time in children with cerebral palsy: A randomized controlled trial.

PubMed

Pourazar, Morteza; Mirakhori, Fatemeh; Hemayattalab, Rasool; Bagherzadeh, Fazlolah

2017-09-21

The purpose of this study was to investigate the training effects of Virtual Reality (VR) intervention program on reaction time in children with cerebral palsy. Thirty boys ranging from 7 to 12 years (mean = 11.20; SD = .76) were selected by available sampling method and randomly divided into the experimental and control groups. Simple Reaction Time (SRT) and Discriminative Reaction Time (DRT) were measured at baseline and 1 day after completion of VR intervention. Multivariate analysis of variance (MANOVA) and paired sample t-test were performed to analyze the results. MANOVA test revealed significant effects for group in posttest phase, with lower reaction time in both measures for the experimental group. Based on paired sample t-test results, both RT measures significantly improved in experimental group following the VR intervention program. This paper proposes VR as a promising tool into the rehabilitation process for improving reaction time in children with cerebral palsy.

Designing communication and remote controlling of virtual instrument network system

NASA Astrophysics Data System (ADS)

Lei, Lin; Wang, Houjun; Zhou, Xue; Zhou, Wenjian

2005-01-01

In this paper, a virtual instrument network through the LAN and finally remote control of virtual instruments is realized based on virtual instrument and LabWindows/CVI software platform. The virtual instrument network system is made up of three subsystems. There are server subsystem, telnet client subsystem and local instrument control subsystem. This paper introduced virtual instrument network structure in detail based on LabWindows. Application procedure design of virtual instrument network communication, the Client/the programming mode of the server, remote PC and server communication far realizing, the control power of the workstation is transmitted, server program and so on essential technical were introduced. And virtual instruments network may connect to entire Internet on. Above-mentioned technology, through measuring the application in the electronic measurement virtual instrument network that is already built up, has verified the actual using value of the technology. Experiment and application validate that this design is resultful.

Training wheelchair navigation in immersive virtual environments for patients with spinal cord injury - end-user input to design an effective system.

PubMed

Nunnerley, Joanne; Gupta, Swati; Snell, Deborah; King, Marcus

2017-05-01

A user-centred design was used to develop and test the feasibility of an immersive 3D virtual reality wheelchair training tool for people with spinal cord injury (SCI). A Wheelchair Training System was designed and modelled using the Oculus Rift headset and a Dynamic Control wheelchair joystick. The system was tested by clinicians and expert wheelchair users with SCI. Data from focus groups and individual interviews were analysed using a general inductive approach to thematic analysis. Four themes emerged: Realistic System, which described the advantages of a realistic virtual environment; a Wheelchair Training System, which described participants' thoughts on the wheelchair training applications; Overcoming Resistance to Technology, the obstacles to introducing technology within the clinical setting; and Working outside the Rehabilitation Bubble which described the protective hospital environment. The Oculus Rift Wheelchair Training System has the potential to provide a virtual rehabilitation setting which could allow wheelchair users to learn valuable community wheelchair use in a safe environment. Nausea appears to be a side effect of the system, which will need to be resolved before this can be a viable clinical tool. Implications for Rehabilitation Immersive virtual reality shows promising benefit for wheelchair training in a rehabilitation setting. Early engagement with consumers can improve product development.

The Immersive Virtual Reality Lab: Possibilities for Remote Experimental Manipulations of Autonomic Activity on a Large Scale.

PubMed

Juvrud, Joshua; Gredebäck, Gustaf; Åhs, Fredrik; Lerin, Nils; Nyström, Pär; Kastrati, Granit; Rosén, Jörgen

2018-01-01

There is a need for large-scale remote data collection in a controlled environment, and the in-home availability of virtual reality (VR) and the commercial availability of eye tracking for VR present unique and exciting opportunities for researchers. We propose and provide a proof-of-concept assessment of a robust system for large-scale in-home testing using consumer products that combines psychophysiological measures and VR, here referred to as a Virtual Lab. For the first time, this method is validated by correlating autonomic responses, skin conductance response (SCR), and pupillary dilation, in response to a spider, a beetle, and a ball using commercially available VR. Participants demonstrated greater SCR and pupillary responses to the spider, and the effect was dependent on the proximity of the stimuli to the participant, with a stronger response when the spider was close to the virtual self. We replicated these effects across two experiments and in separate physical room contexts to mimic variability in home environment. Together, these findings demonstrate the utility of pupil dilation as a marker of autonomic arousal and the feasibility to assess this in commercially available VR hardware and support a robust Virtual Lab tool for massive remote testing.

The Immersive Virtual Reality Lab: Possibilities for Remote Experimental Manipulations of Autonomic Activity on a Large Scale

PubMed Central

Juvrud, Joshua; Gredebäck, Gustaf; Åhs, Fredrik; Lerin, Nils; Nyström, Pär; Kastrati, Granit; Rosén, Jörgen

2018-01-01

There is a need for large-scale remote data collection in a controlled environment, and the in-home availability of virtual reality (VR) and the commercial availability of eye tracking for VR present unique and exciting opportunities for researchers. We propose and provide a proof-of-concept assessment of a robust system for large-scale in-home testing using consumer products that combines psychophysiological measures and VR, here referred to as a Virtual Lab. For the first time, this method is validated by correlating autonomic responses, skin conductance response (SCR), and pupillary dilation, in response to a spider, a beetle, and a ball using commercially available VR. Participants demonstrated greater SCR and pupillary responses to the spider, and the effect was dependent on the proximity of the stimuli to the participant, with a stronger response when the spider was close to the virtual self. We replicated these effects across two experiments and in separate physical room contexts to mimic variability in home environment. Together, these findings demonstrate the utility of pupil dilation as a marker of autonomic arousal and the feasibility to assess this in commercially available VR hardware and support a robust Virtual Lab tool for massive remote testing. PMID:29867318

Stroke rehabilitation at home using virtual reality, haptics and telemedicine.

PubMed

Rydmark, Martin; Broeren, Jörgen; Pascher, Ragnar

2002-01-01

The objective of this pilot study is to identify the level of difficulty in which subjects with left hemisphere damage in the acute phase after stroke can start practicing in a virtual environment. Second, to test an application of Virtual Reality technology to existing occupational treatment methods in stroke rehabilitation and develop a platform for home rehabilitation controlled telemedically. The findings indicate that the system shows potential as an assessment and training device. The feasibility study setup is working well likewise the assessment method. Developing and increasing the complexity of the tasks must be based on the patient individual neurology, and that the cinematic motion patterns of the patient's are the basis for exercise design.

Mechanism of Kinect-based virtual reality training for motor functional recovery of upper limbs after subacute stroke.

PubMed

Bao, Xiao; Mao, Yurong; Lin, Qiang; Qiu, Yunhai; Chen, Shaozhen; Li, Le; Cates, Ryan S; Zhou, Shufeng; Huang, Dongfeng

2013-11-05

The Kinect-based virtual reality system for the Xbox 360 enables users to control and interact with the game console without the need to touch a game controller, and provides rehabilitation training for stroke patients with lower limb dysfunctions. However, the underlying mechanism remains unclear. In this study, 18 healthy subjects and five patients after subacute stroke were included. The five patients were scanned using functional MRI prior to training, 3 weeks after training and at a 12-week follow-up, and then compared with healthy subjects. The Fugl-Meyer Assessment and Wolf Motor Function Test scores of the hemiplegic upper limbs of stroke patients were significantly increased 3 weeks after training and at the 12-week follow-up. Functional MRI results showed that contralateral primary sensorimotor cortex was activated after Kinect-based virtual reality training in the stroke patients compared with the healthy subjects. Contralateral primary sensorimotor cortex, the bilateral supplementary motor area and the ipsilateral cerebellum were also activated during hand-clenching in all 18 healthy subjects. Our findings indicate that Kinect-based virtual reality training could promote the recovery of upper limb motor function in subacute stroke patients, and brain reorganization by Kinect-based virtual reality training may be linked to the contralateral sensorimotor cortex.

Mechanism of Kinect-based virtual reality training for motor functional recovery of upper limbs after subacute stroke

PubMed Central

Bao, Xiao; Mao, Yurong; Lin, Qiang; Qiu, Yunhai; Chen, Shaozhen; Li, Le; Cates, Ryan S.; Zhou, Shufeng; Huang, Dongfeng

2013-01-01

The Kinect-based virtual reality system for the Xbox 360 enables users to control and interact with the game console without the need to touch a game controller, and provides rehabilitation training for stroke patients with lower limb dysfunctions. However, the underlying mechanism remains unclear. In this study, 18 healthy subjects and five patients after subacute stroke were included. The five patients were scanned using functional MRI prior to training, 3 weeks after training and at a 12-week follow-up, and then compared with healthy subjects. The Fugl-Meyer Assessment and Wolf Motor Function Test scores of the hemiplegic upper limbs of stroke patients were significantly increased 3 weeks after training and at the 12-week follow-up. Functional MRI results showed that contralateral primary sensorimotor cortex was activated after Kinect-based virtual reality training in the stroke patients compared with the healthy subjects. Contralateral primary sensorimotor cortex, the bilateral supplementary motor area and the ipsilateral cerebellum were also activated during hand-clenching in all 18 healthy subjects. Our findings indicate that Kinect-based virtual reality training could promote the recovery of upper limb motor function in subacute stroke patients, and brain reorganization by Kinect-based virtual reality training may be linked to the contralateral sensorimotor cortex. PMID:25206611

Local and Remote Cooperation With Virtual and Robotic Agents: A P300 BCI Study in Healthy and People Living With Spinal Cord Injury.

PubMed

Tidoni, Emmanuele; Abu-Alqumsan, Mohammad; Leonardis, Daniele; Kapeller, Christoph; Fusco, Gabriele; Guger, Cristoph; Hintermuller, Cristoph; Peer, Angelika; Frisoli, Antonio; Tecchia, Franco; Bergamasco, Massimo; Aglioti, Salvatore Maria

2017-09-01

The development of technological applications that allow people to control and embody external devices within social interaction settings represents a major goal for current and future brain-computer interface (BCI) systems. Prior research has suggested that embodied systems may ameliorate BCI end-user's experience and accuracy in controlling external devices. Along these lines, we developed an immersive P300-based BCI application with a head-mounted display for virtual-local and robotic-remote social interactions and explored in a group of healthy participants the role of proprioceptive feedback in the control of a virtual surrogate (Study 1). Moreover, we compared the performance of a small group of people with spinal cord injury (SCI) to a control group of healthy subjects during virtual and robotic social interactions (Study 2), where both groups received a proprioceptive stimulation. Our attempt to combine immersive environments, BCI technologies and neuroscience of body ownership suggests that providing realistic multisensory feedback still represents a challenge. Results have shown that healthy and people living with SCI used the BCI within the immersive scenarios with good levels of performance (as indexed by task accuracy, optimizations calls and Information Transfer Rate) and perceived control of the surrogates. Proprioceptive feedback did not contribute to alter performance measures and body ownership sensations. Further studies are necessary to test whether sensorimotor experience represents an opportunity to improve the use of future embodied BCI applications.

Determining if Instructional Delivery Model Differences Exist in Remedial English

ERIC Educational Resources Information Center

Carter, LaTanya Woods

2012-01-01

The purpose of this causal comparative study is to test the theory of no significant difference that compares pre- and post-test assessment scores, controlling for the instructional delivery model of online and face-to-face students at a Mid-Atlantic university. Online education and virtual distance learning programs have increased in popularity…

NREL, EPRI Validate Advanced Microgrid Controller with ESIF's Virtual

Science.gov Websites

Microgrid Controller with ESIF's Virtual Microgrid Model NREL, EPRI Validate Advanced Microgrid Controller with ESIF's Virtual Microgrid Model NREL is working with the Electric Power Research Institute (EPRI Energy Systems Integration Facility, by connecting it to a virtual model of a microgrid. NREL researchers

Virtual Reality-Based Training to Improve Obstacle-Crossing Performance and Dynamic Balance in Patients With Parkinson's Disease.

PubMed

Liao, Ying-Yi; Yang, Yea-Ru; Cheng, Shih-Jung; Wu, Yih-Ru; Fuh, Jong-Ling; Wang, Ray-Yau

2015-08-01

Obstacle crossing is a balance-challenging task and can cause falls in people with Parkinson's disease (PD). However, programs for people with PD that effectively target obstacle crossing and dynamic balance have not been established. To examine the effects of virtual reality-based exercise on obstacle crossing performance and dynamic balance in participants with PD. Thirty-six participants with a diagnosis of PD (Hoehn and Yahr score ranging 1 to 3) were randomly assigned to one of three groups. In the exercise groups, participants received virtual reality-based Wii Fit exercise (VRWii group) or traditional exercise (TE group) for 45 minutes, followed by 15 minutes of treadmill training in each session for a total of 12 sessions over 6 weeks. Participants in the control group received no structured exercise program. Primary outcomes included obstacle crossing performance (crossing velocity, stride length, and vertical toe obstacle clearance) and dynamic balance (maximal excursion, movement velocity, and directional control measured by the limits-of-stability test). Secondary outcomes included sensory organization test (SOT), Parkinson's Disease Questionnaire (PDQ39), fall efficacy scale (FES-I), and timed up and go test (TUG). All outcomes were assessed at baseline, after training, and at 1-month follow-up. The VRWii group showed greater improvement in obstacle crossing velocity, crossing stride length, dynamic balance, SOT, TUG, FES-I, and PDQ39 than the control group. VRWii training also resulted in greater improvement in movement velocity of limits-of-stability test than TE training. VRWii training significantly improved obstacle crossing performance and dynamic balance, supporting implementation of VRWii training in participants with PD. © The Author(s) 2014.

Near-Infrared Spectroscopy-Based Frontal Lobe Neurofeedback Integrated in Virtual Reality Modulates Brain and Behavior in Highly Impulsive Adults

PubMed Central

Hudak, Justin; Blume, Friederike; Dresler, Thomas; Haeussinger, Florian B.; Renner, Tobias J.; Fallgatter, Andreas J.; Gawrilow, Caterina; Ehlis, Ann-Christine

2017-01-01

Based on neurofeedback (NF) training as a neurocognitive treatment in attention-deficit/hyperactivity disorder (ADHD), we designed a randomized, controlled functional near-infrared spectroscopy (fNIRS) NF intervention embedded in an immersive virtual reality classroom in which participants learned to control overhead lighting with their dorsolateral prefrontal brain activation. We tested the efficacy of the intervention on healthy adults displaying high impulsivity as a sub-clinical population sharing common features with ADHD. Twenty participants, 10 in an experimental and 10 in a shoulder muscle-based electromyography control group, underwent eight training sessions across 2 weeks. Training was bookended by a pre- and post-test including go/no-go, n-back, and stop-signal tasks (SST). Results indicated a significant reduction in commission errors on the no-go task with a simultaneous increase in prefrontal oxygenated hemoglobin concentration for the experimental group, but not for the control group. Furthermore, the ability of the subjects to gain control over the feedback parameter correlated strongly with the reduction in commission errors for the experimental, but not for the control group, indicating the potential importance of learning feedback control in moderating behavioral outcomes. In addition, participants of the fNIRS group showed a reduction in reaction time variability on the SST. Results indicate a clear effect of our NF intervention in reducing impulsive behavior possibly via a strengthening of frontal lobe functioning. Virtual reality additions to conventional NF may be one way to improve the ecological validity and symptom-relevance of the training situation, hence positively affecting transfer of acquired skills to real life. PMID:28928644

Virtual reality conditioned place preference using monetary reward.

PubMed

Childs, Emma; Astur, Robert S; de Wit, Harriet

2017-03-30

Computerized tasks based on conditioned place preference (CPP) methodology offer the opportunity to study learning mechanisms involved in conditioned reward in humans. In this study, we examined acquisition and extinction of a CPP for virtual environments associated with monetary reward ($). Healthy men and women (N=57) completed a computerized CPP task in which they controlled an avatar within a virtual environment. On day 1, subjects completed 6 conditioning trials in which one room was paired with high $ and another with low $. Acquisition of place conditioning was assessed by measuring the time spent in each room during an exploration test of the virtual environments and using self-reported ratings of room liking and preference. Twenty-four hours later, retention and extinction of CPP were assessed during 4 successive exploration tests of the virtual environments. Participants exhibited a place preference for (spent significantly more time in) the virtual room paired with high $ over the one paired with low $ (p=0.015). They also reported that they preferred the high $ room (p<0.001) and liked it significantly more than the low $ room (p<0.001). However, these preferences were short-lived: 24h later subjects did not exhibit a behavioral or subjective preference for the high $ room. These findings show that individuals exhibit transient behavioral and subjective preferences for a virtual environment paired with monetary reward. Variations on this task may be useful to study mechanisms and brain substrates involved in conditioned reward and to examine the influence of drugs upon appetitive conditioning. Copyright © 2017 Elsevier B.V. All rights reserved.

Cognitive ability predicts motor learning on a virtual reality game in patients with TBI.

PubMed

O'Neil, Rochelle L; Skeel, Reid L; Ustinova, Ksenia I

2013-01-01

Virtual reality games and simulations have been utilized successfully for motor rehabilitation of individuals with traumatic brain injury (TBI). Little is known, however, how TBI-related cognitive decline affects learning of motor tasks in virtual environments. To fill this gap, we examined learning within a virtual reality game involving various reaching motions in 14 patients with TBI and 15 healthy individuals with different cognitive abilities. All participants practiced ten 90-second gaming trials to assess various aspects of motor learning. Cognitive abilities were assessed with a battery of tests including measures of memory, executive functioning, and visuospatial ability. Overall, participants with TBI showed both reduced performance and a slower learning rate in the virtual reality game compared to healthy individuals. Numerous correlations between overall performance and several of the cognitive ability domains were revealed for both the patient and control groups, with the best predictor being overall cognitive ability. The results may provide a starting point for rehabilitation programs regarding which cognitive domains interact with motor learning.

Virtualization for the LHCb Online system

NASA Astrophysics Data System (ADS)

Bonaccorsi, Enrico; Brarda, Loic; Moine, Gary; Neufeld, Niko

2011-12-01

Virtualization has long been advertised by the IT-industry as a way to cut down cost, optimise resource usage and manage the complexity in large data-centers. The great number and the huge heterogeneity of hardware, both industrial and custom-made, has up to now led to reluctance in the adoption of virtualization in the IT infrastructure of large experiment installations. Our experience in the LHCb experiment has shown that virtualization improves the availability and the manageability of the whole system. We have done an evaluation of available hypervisors / virtualization solutions and find that the Microsoft HV technology provides a high level of maturity and flexibility for our purpose. We present the results of these comparison tests, describing in detail, the architecture of our virtualization infrastructure with a special emphasis on the security for services visible to the outside world. Security is achieved by a sophisticated combination of VLANs, firewalls and virtual routing - the cost and benefits of this solution are analysed. We have adapted our cluster management tools, notably Quattor, for the needs of virtual machines and this allows us to migrate smoothly services on physical machines to the virtualized infrastructure. The procedures for migration will also be described. In the final part of the document we describe our recent R&D activities aiming to replacing the SAN-backend for the virtualization by a cheaper iSCSI solution - this will allow to move all servers and related services to the virtualized infrastructure, excepting the ones doing hardware control via non-commodity PCI plugin cards.

Aircraft panel with sensorless active sound power reduction capabilities through virtual mechanical impedances

NASA Astrophysics Data System (ADS)

Boulandet, R.; Michau, M.; Micheau, P.; Berry, A.

2016-01-01

This paper deals with an active structural acoustic control approach to reduce the transmission of tonal noise in aircraft cabins. The focus is on the practical implementation of the virtual mechanical impedances method by using sensoriactuators instead of conventional control units composed of separate sensors and actuators. The experimental setup includes two sensoriactuators developed from the electrodynamic inertial exciter and distributed over an aircraft trim panel which is subject to a time-harmonic diffuse sound field. The target mechanical impedances are first defined by solving a linear optimization problem from sound power measurements before being applied to the test panel using a complex envelope controller. Measured data are compared to results obtained with sensor-actuator pairs consisting of an accelerometer and an inertial exciter, particularly as regards sound power reduction. It is shown that the two types of control unit provide similar performance, and that here virtual impedance control stands apart from conventional active damping. In particular, it is clear from this study that extra vibrational energy must be provided by the actuators for optimal sound power reduction, mainly due to the high structural damping in the aircraft trim panel. Concluding remarks on the benefits of using these electrodynamic sensoriactuators to control tonal disturbances are also provided.

Virtual experiments, physical validation: dental morphology at the intersection of experiment and theory

PubMed Central

Anderson, P. S. L.; Rayfield, E. J.

2012-01-01

Computational models such as finite-element analysis offer biologists a means of exploring the structural mechanics of biological systems that cannot be directly observed. Validated against experimental data, a model can be manipulated to perform virtual experiments, testing variables that are hard to control in physical experiments. The relationship between tooth form and the ability to break down prey is key to understanding the evolution of dentition. Recent experimental work has quantified how tooth shape promotes fracture in biological materials. We present a validated finite-element model derived from physical compression experiments. The model shows close agreement with strain patterns observed in photoelastic test materials and reaction forces measured during these experiments. We use the model to measure strain energy within the test material when different tooth shapes are used. Results show that notched blades deform materials for less strain energy cost than straight blades, giving insights into the energetic relationship between tooth form and prey materials. We identify a hypothetical ‘optimal’ blade angle that minimizes strain energy costs and test alternative prey materials via virtual experiments. Using experimental data and computational models offers an integrative approach to understand the mechanics of tooth morphology. PMID:22399789

Simulation-based Testing of Control Software

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ozmen, Ozgur; Nutaro, James J.; Sanyal, Jibonananda

It is impossible to adequately test complex software by examining its operation in a physical prototype of the system monitored. Adequate test coverage can require millions of test cases, and the cost of equipment prototypes combined with the real-time constraints of testing with them makes it infeasible to sample more than a small number of these tests. Model based testing seeks to avoid this problem by allowing for large numbers of relatively inexpensive virtual prototypes that operate in simulation time at a speed limited only by the available computing resources. In this report, we describe how a computer system emulatormore » can be used as part of a model based testing environment; specifically, we show that a complete software stack including operating system and application software - can be deployed within a simulated environment, and that these simulations can proceed as fast as possible. To illustrate this approach to model based testing, we describe how it is being used to test several building control systems that act to coordinate air conditioning loads for the purpose of reducing peak demand. These tests involve the use of ADEVS (A Discrete Event System Simulator) and QEMU (Quick Emulator) to host the operational software within the simulation, and a building model developed with the MODELICA programming language using Buildings Library and packaged as an FMU (Functional Mock-up Unit) that serves as the virtual test environment.« less

Using virtual reality to train children in safe street-crossing skills.

PubMed

Schwebel, David C; McClure, Leslie A

2010-02-01

Pedestrian injuries are among the leading causes of morbidity and mortality in middle childhood. One limitation to existing pedestrian safety interventions is that they do not provide children with repeated practice needed to develop the complex perceptual and cognitive skills required for safe street crossing. Virtual reality offers training through repeated unsupervised practice without risk, automated feedback on success of crossings, adjustment of traffic to match children's skill and a fun, appealing environment for training. To test the efficacy of virtual reality to train child pedestrians in safe street crossing. Birmingham, Alabama, USA. A randomised controlled trial is underway with an expected sample of four groups of 60 children aged 7-8 years (total N=240). One group receives training in an interactive, immersive virtual pedestrian environment. A second receives pedestrian safety training via widely used video and computer strategies. The third group receives what is judged to be the most efficacious treatment currently available, individualised behavioural training at streetside locations. The fourth group serves as a no-contact control group. All participants are exposed to a range of field and laboratory-based measures of pedestrian skill during baseline and post-intervention visits, as well as during a 6-month follow-up assessment. Primary analyses will be conducted through linear mixed models testing change over time in the four intervention groups. Three pedestrian safety measures will serve as primary outcomes: temporal gap before initiating crossing, temporal gap remaining after crossing and attention to traffic while waiting to cross.

A low cost virtual reality system for home based rehabilitation of the arm following stroke: a randomised controlled feasibility trial

PubMed Central

Standen, PJ; Threapleton, K; Richardson, A; Connell, L; Brown, DJ; Battersby, S; Platts, F; Burton, A

2016-01-01

Objective: To assess the feasibility of conducting a randomised controlled trial of a home-based virtual reality system for rehabilitation of the arm following stroke. Design: Two group feasibility randomised controlled trial of intervention versus usual care. Setting: Patients’ homes. Participants: Patients aged 18 or over, with residual arm dysfunction following stroke and no longer receiving any other intensive rehabilitation. Interventions: Eight weeks’ use of a low cost home-based virtual reality system employing infra-red capture to translate the position of the hand into game play or usual care. Main measures: The primary objective was to collect information on the feasibility of a trial, including recruitment, collection of outcome measures and staff support required. Patients were assessed at three time points using the Wolf Motor Function Test, Nine-Hole Peg Test, Motor Activity Log and Nottingham Extended Activities of Daily Living. Results: Over 15 months only 47 people were referred to the team. Twenty seven were randomised and 18 (67%) of those completed final outcome measures. Sample size calculation based on data from the Wolf Motor Function Test indicated a requirement for 38 per group. There was a significantly greater change from baseline in the intervention group on midpoint Wolf Grip strength and two subscales of the final Motor Activity Log. Training in the use of the equipment took a median of 230 minutes per patient. Conclusions: To achieve the required sample size, a definitive home-based trial would require additional strategies to boost recruitment rates and adequate resources for patient support. PMID:27029939

A low cost virtual reality system for home based rehabilitation of the arm following stroke: a randomised controlled feasibility trial.

PubMed

Standen, P J; Threapleton, K; Richardson, A; Connell, L; Brown, D J; Battersby, S; Platts, F; Burton, A

2017-03-01

To assess the feasibility of conducting a randomised controlled trial of a home-based virtual reality system for rehabilitation of the arm following stroke. Two group feasibility randomised controlled trial of intervention versus usual care. Patients' homes. Patients aged 18 or over, with residual arm dysfunction following stroke and no longer receiving any other intensive rehabilitation. Eight weeks' use of a low cost home-based virtual reality system employing infra-red capture to translate the position of the hand into game play or usual care. The primary objective was to collect information on the feasibility of a trial, including recruitment, collection of outcome measures and staff support required. Patients were assessed at three time points using the Wolf Motor Function Test, Nine-Hole Peg Test, Motor Activity Log and Nottingham Extended Activities of Daily Living. Over 15 months only 47 people were referred to the team. Twenty seven were randomised and 18 (67%) of those completed final outcome measures. Sample size calculation based on data from the Wolf Motor Function Test indicated a requirement for 38 per group. There was a significantly greater change from baseline in the intervention group on midpoint Wolf Grip strength and two subscales of the final Motor Activity Log. Training in the use of the equipment took a median of 230 minutes per patient. To achieve the required sample size, a definitive home-based trial would require additional strategies to boost recruitment rates and adequate resources for patient support.

Some criteria for teleoperators and virtual environments from experiences with vehicle/operator simulation

NASA Technical Reports Server (NTRS)

Jex, Henry R.

1991-01-01

A review is given of a wide range of simulations in which operator steering control of a vehicle is involved and the dominant-clues, closed-loop bandwidth, measured operator effective time-delay, and ratio of bandwidth-to-inverse delay are summarized. A correlation of kinetosis with dynamic scene field-of-view is shown. The use of moving base simulators to improve the validity of locomotion teleoperations is discussed. some rules-of-thumb for good 'feel-system' simulation, such as for control manipulanda are given. Finally, simulation tests of teleoperators and virtual environments should include three types of measures: system performance, operator (or robot) 'behavior', and mental workload evaluations.

Virtual reality exposure therapy for social anxiety disorder: a randomized controlled trial.

PubMed

Anderson, Page L; Price, Matthew; Edwards, Shannan M; Obasaju, Mayowa A; Schmertz, Stefan K; Zimand, Elana; Calamaras, Martha R

2013-10-01

This is the first randomized trial comparing virtual reality exposure therapy to in vivo exposure for social anxiety disorder. Participants with a principal diagnosis of social anxiety disorder who identified public speaking as their primary fear (N = 97) were recruited from the community, resulting in an ethnically diverse sample (M age = 39 years) of mostly women (62%). Participants were randomly assigned to and completed 8 sessions of manualized virtual reality exposure therapy, exposure group therapy, or wait list. Standardized self-report measures were collected at pretreatment, posttreatment, and 12-month follow-up, and process measures were collected during treatment. A standardized speech task was delivered at pre- and posttreatment, and diagnostic status was reassessed at 3-month follow-up. Analysis of covariance showed that, relative to wait list, people completing either active treatment significantly improved on all but one measure (length of speech for exposure group therapy and self-reported fear of negative evaluation for virtual reality exposure therapy). At 12-month follow-up, people showed significant improvement from pretreatment on all measures. There were no differences between the active treatments on any process or outcome measure at any time, nor differences on achieving partial or full remission. Virtual reality exposure therapy is effective for treating social fears, and improvement is maintained for 1 year. Virtual reality exposure therapy is equally effective as exposure group therapy; further research with a larger sample is needed, however, to better control and statistically test differences between the treatments.

Virtual Sensors for Designing Irrigation Controllers in Greenhouses

PubMed Central

Sánchez, Jorge Antonio; Rodríguez, Francisco; Guzmán, José Luis; Arahal, Manuel R

2012-01-01

Monitoring the greenhouse transpiration for control purposes is currently a difficult task. The absence of affordable sensors that provide continuous transpiration measurements motivates the use of estimators. In the case of tomato crops, the availability of estimators allows the design of automatic fertirrigation (irrigation + fertilization) schemes in greenhouses, minimizing the dispensed water while fulfilling crop needs. This paper shows how system identification techniques can be applied to obtain nonlinear virtual sensors for estimating transpiration. The greenhouse used for this study is equipped with a microlysimeter, which allows one to continuously sample the transpiration values. While the microlysimeter is an advantageous piece of equipment for research, it is also expensive and requires maintenance. This paper presents the design and development of a virtual sensor to model the crop transpiration, hence avoiding the use of this kind of expensive sensor. The resulting virtual sensor is obtained by dynamical system identification techniques based on regressors taken from variables typically found in a greenhouse, such as global radiation and vapor pressure deficit. The virtual sensor is thus based on empirical data. In this paper, some effort has been made to eliminate some problems associated with grey-box models: advance phenomenon and overestimation. The results are tested with real data and compared with other approaches. Better results are obtained with the use of nonlinear Black-box virtual sensors. This sensor is based on global radiation and vapor pressure deficit (VPD) measurements. Predictive results for the three models are developed for comparative purposes. PMID:23202208

Charliecloud

DOE Office of Scientific and Technical Information (OSTI.GOV)

Priedhorsky, Reid; Randles, Tim

Charliecloud is a set of scripts to let users run a virtual cluster of virtual machines (VMs) on a desktop or supercomputer. Key functions include: 1. Creating (typically by installing an operating system from vendor media) and updating VM images; 2. Running a single VM; 3. Running multiple VMs in a virtual cluster. The virtual machines can talk to one another over the network and (in some cases) the outside world. This is accomplished by calling external programs such as QEMU and the Virtual Distributed Ethernet (VDE) suite. The goal is to let users have a virtual cluster containing nodesmore » where they have privileged access, while isolating that privilege within the virtual cluster so it cannot affect the physical compute resources. Host configuration enforces security; this is not included in Charliecloud, though security guidelines are included in its documentation and Charliecloud is designed to facilitate such configuration. Charliecloud manages passing information from host computers into and out of the virtual machines, such as parameters of the virtual cluster, input data specified by the user, output data from virtual compute jobs, VM console display, and network connections (e.g., SSH or X11). Parameters for the virtual cluster (number of VMs, RAM and disk per VM, etc.) are specified by the user or gathered from the environment (e.g., SLURM environment variables). Example job scripts are included. These include computation examples (such as a "hello world" MPI job) as well as performance tests. They also include a security test script to verify that the virtual cluster is appropriately sandboxed. Tests include: 1. Pinging hosts inside and outside the virtual cluster to explore connectivity; 2. Port scans (again inside and outside) to see what services are available; 3. Sniffing tests to see what traffic is visible to running VMs; 4. IP address spoofing to test network functionality in this case; 5. File access tests to make sure host access permissions are enforced. This test script is not a comprehensive scanner and does not test for specific vulnerabilities. Importantly, no information about physical hosts or network topology is included in this script (or any of Charliecloud); while part of a sensible test, such information is specified by the user when the test is run. That is, one cannot learn anything about the LANL network or computing infrastructure by examining Charliecloud code.« less

Virtual reality as a screening tool for sports concussion in adolescents.

PubMed

Nolin, Pierre; Stipanicic, Annie; Henry, Mylène; Joyal, Christian C; Allain, Philippe

2012-01-01

There is controversy surrounding the cognitive effects of sports concussion. This study aimed to verify whether the technique of virtual reality could aid in the identification of attention and inhibition deficits in adolescents. A prospective design was used to assess 25 sports-concussed and 25 non-sports-concussed adolescents enrolled in a sport and education programme. Participants were evaluated in immersive virtual reality via ClinicaVR: Classroom-CPT and in real life via the traditional VIGIL-CPT. The neuropsychological assessment using virtual reality showed greater sensitivity to the subtle effects of sports concussion compared to the traditional test, which showed no difference between groups. The results also demonstrated that the sports concussion group reported more symptoms of cybersickness and more intense cybersickness than the control group. Sports concussion was associated with subtle deficits in attention and inhibition. However, further studies are needed to support these results.

Serious games for screening pre-dementia conditions: from virtuality to reality? A pilot project.

PubMed

Zucchella, Chiara; Sinforiani, Elena; Tassorelli, Cristina; Cavallini, Elena; Tost-Pardell, Daniela; Grau, Sergi; Pazzi, Stefania; Puricelli, Stefano; Bernini, Sara; Bottiroli, Sara; Vecchi, Tomaso; Sandrini, Giorgio; Nappi, Giuseppe

2014-01-01

Conventional cognitive assessment is based on a pencil-and-paper neuropsychological evaluation, which is time consuming, expensive and requires the involvement of several professionals. Information and communication technology could be exploited to allow the development of tools that are easy to use, reduce the amount of data processing, and provide controllable test conditions. Serious games (SGs) have the potential to be new and effective tools in the management and treatment of cognitive impairments Serious games for screening pre-dementia conditions: from virtuality to reality? A pilot project in the elderly. Moreover, by adopting SGs in 3D virtual reality settings, cognitive functions might be evaluated using tasks that simulate daily activities, increasing the "ecological validity" of the assessment. In this commentary we report our experience in the creation of the Smart Aging platform, a 3D SGand virtual environment-based platform for the early identification and characterization of mild cognitive impairment.

The Role of Visualization in Learning from Computer-Based Images. Research Report

ERIC Educational Resources Information Center

Piburn, Michael D.; Reynolds, Stephen J.; McAuliffe, Carla; Leedy, Debra E.; Birk, James P.; Johnson, Julia K.

2005-01-01

Among the sciences, the practice of geology is especially visual. To assess the role of spatial ability in learning geology, we designed an experiment using: (1) web-based versions of spatial visualization tests, (2) a geospatial test, and (3) multimedia instructional modules built around QuickTime Virtual Reality movies. Students in control and…

Development of hybrid electric vehicle powertrain test system based on virtue instrument

NASA Astrophysics Data System (ADS)

Xu, Yanmin; Guo, Konghui; Chen, Liming

2017-05-01

Hybrid powertrain has become the standard configuration of some automobile models. The test system of hybrid vehicle powertrain was developed based on virtual instrument, using electric dynamometer to simulate the work of engines, to test the motor and control unit of the powertrain. The test conditions include starting, acceleration, and deceleration. The results show that the test system can simulate the working conditions of the hybrid electric vehicle powertrain under various conditions.

A Cooperative Approach to Virtual Machine Based Fault Injection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Naughton III, Thomas J; Engelmann, Christian; Vallee, Geoffroy R

Resilience investigations often employ fault injection (FI) tools to study the effects of simulated errors on a target system. It is important to keep the target system under test (SUT) isolated from the controlling environment in order to maintain control of the experiement. Virtual machines (VMs) have been used to aid these investigations due to the strong isolation properties of system-level virtualization. A key challenge in fault injection tools is to gain proper insight and context about the SUT. In VM-based FI tools, this challenge of target con- text is increased due to the separation between host and guest (VM).more » We discuss an approach to VM-based FI that leverages virtual machine introspection (VMI) methods to gain insight into the target s context running within the VM. The key to this environment is the ability to provide basic information to the FI system that can be used to create a map of the target environment. We describe a proof- of-concept implementation and a demonstration of its use to introduce simulated soft errors into an iterative solver benchmark running in user-space of a guest VM.« less

Virtual reality in neurologic rehabilitation of spatial disorientation

PubMed Central

2013-01-01

Background Topographical disorientation (TD) is a severe and persistent impairment of spatial orientation and navigation in familiar as well as new environments and a common consequence of brain damage. Virtual reality (VR) provides a new tool for the assessment and rehabilitation of TD. In VR training programs different degrees of active motor control over navigation may be implemented (i.e. more passive spatial navigation vs. more active). Increasing demands of active motor control may overload those visuo-spatial resources necessary for learning spatial orientation and navigation. In the present study we used a VR-based verbally-guided passive navigation training program to improve general spatial abilities in neurologic patients with spatial disorientation. Methods Eleven neurologic patients with focal brain lesions, which showed deficits in spatial orientation, as well as 11 neurologic healthy controls performed a route finding training in a virtual environment. Participants learned and recalled different routes for navigation in a virtual city over five training sessions. Before and after VR training, general spatial abilities were assessed with standardized neuropsychological tests. Results Route finding ability in the VR task increased over the five training sessions. Moreover, both groups improved different aspects of spatial abilities after VR training in comparison to the spatial performance before VR training. Conclusions Verbally-guided passive navigation training in VR enhances general spatial cognition in neurologic patients with spatial disorientation as well as in healthy controls and can therefore be useful in the rehabilitation of spatial deficits associated with TD. PMID:23394289

Biomechanical Analysis of Locust Jumping in a Physically Realistic Virtual Environment

NASA Astrophysics Data System (ADS)

Cofer, David; Cymbalyuk, Gennady; Heitler, William; Edwards, Donald

2008-03-01

The biomechanical and neural components that underlie locust jumping have been extensively studied. Previous research suggested that jump energy is stored primarily in the extensor apodeme, and in a band of cuticle called the semi-lunar process (SLP). As it has thus far proven impossible to experimentally alter the SLP without rendering a locust unable to jump, it has not been possible to test whether the energy stored in the SLP has a significant impact on the jump. To address problems such as this we have developed a software toolkit, AnimatLab, which allows researchers to build and test virtual organisms. We used this software to build a virtual locust, and then asked how the SLP is utilized during jumping. The results show that without the SLP the jump distance was reduced by almost half. Further, the simulations were also able to show that loss of the SLP had a significant impact on the final phase of the jump. We are currently working on postural control mechanisms for targeted jumping in locust.

Application of virtual reality graphics in assessment of concussion.

PubMed

Slobounov, Semyon; Slobounov, Elena; Newell, Karl

2006-04-01

Abnormal balance in individuals suffering from traumatic brain injury (TBI) has been documented in numerous recent studies. However, specific mechanisms causing balance deficits have not been systematically examined. This paper demonstrated the destabilizing effect of visual field motion, induced by virtual reality graphics in concussed individuals but not in normal controls. Fifty five student-athletes at risk for concussion participated in this study prior to injury and 10 of these subjects who suffered MTBI were tested again on day 3, day 10, and day 30 after the incident. Postural responses to visual field motion were recorded using a virtual reality (VR) environment in conjunction with balance (AMTI force plate) and motion tracking (Flock of Birds) technologies. Two experimental conditions were introduced where subjects passively viewed VR scenes or actively manipulated the visual field motion. Long-lasting destabilizing effects of visual field motion were revealed, although subjects were asymptomatic when standard balance tests were introduced. The findings demonstrate that advanced VR technology may detect residual symptoms of concussion at least 30 days post-injury.

Gender issues in the use of virtual environments.

PubMed

Larson, P; Rizzo, A A; Buckwalter, J G; Van Rooyen, A; Kratz, K; Neumann, U; Kesselman, C; Thiebaux, M; Van Der Zaag, C

1999-01-01

Gender differences in cognitive and behavioral performance have been reported throughout the psychological literature. Consequently, gender differences should be considered and controlled for when cognitive research is conducted in virtual environments (VEs). These variables may include gender-related differences in cognitive performance, susceptibility for cybersickness, and the impact of sex hormones on cognition. Such issues are addressed in the context of a recent VE study of the visuospatial ability referred to as mental rotation. The Mental Rotation Test (MRT), a paper and pencil measure, has been shown to produce one of the largest gender differences in the cognitive literature. The outcomes of the MRT are in favor of males. However, results reported from a Virtual Reality Spatial Rotation (VRSR) test demonstrate no gender differences when subjects were able to manually manipulate the stimuli in a VE. Further analysis uncovers gender differences in the patterns of associations between verbal and spatial tasks and performance on VRSR. Results are discussed in terms of dimensionality factors and hemispheric lateralization.

Assessment of the emotional responses produced by exposure to real food, virtual food and photographs of food in patients affected by eating disorders

PubMed Central

2010-01-01

Background Many researchers and clinicians have proposed using virtual reality (VR) in adjunct to in vivo exposure therapy to provide an innovative form of exposure to patients suffering from different psychological disorders. The rationale behind the 'virtual approach' is that real and virtual exposures elicit a comparable emotional reaction in subjects, even if, to date, there are no experimental data that directly compare these two conditions. To test whether virtual stimuli are as effective as real stimuli, and more effective than photographs in the anxiety induction process, we tested the emotional reactions to real food (RF), virtual reality (VR) food and photographs (PH) of food in two samples of patients affected, respectively, by anorexia (AN) and bulimia nervosa (BN) compared to a group of healthy subjects. The two main hypotheses were the following: (a) the virtual exposure elicits emotional responses comparable to those produced by the real exposure; (b) the sense of presence induced by the VR immersion makes the virtual experience more ecological, and consequently more effective than static pictures in producing emotional responses in humans. Methods In total, 10 AN, 10 BN and 10 healthy control subjects (CTR) were randomly exposed to three experimental conditions: RF, PH, and VR while their psychological (Stait Anxiety Inventory (STAI-S) and visual analogue scale for anxiety (VAS-A)) and physiological (heart rate, respiration rate, and skin conductance) responses were recorded. Results RF and VR induced a comparable emotional reaction in patients higher than the one elicited by the PH condition. We also found a significant effect in the subjects' degree of presence experienced in the VR condition about their level of perceived anxiety (STAI-S and VAS-A): the higher the sense of presence, the stronger the level of anxiety. Conclusions Even though preliminary, the present data show that VR is more effective than PH in eliciting emotional responses similar to those expected in real life situations. More generally, the present study suggests the potential of VR in a variety of experimental, training and clinical contexts, being its range of possibilities extremely wide and customizable. In particular, in a psychological perspective based on a cognitive behavioral approach, the use of VR enables the provision of specific contexts to help patients to cope with their diseases thanks to an easily controlled stimulation. PMID:20602749

Virtual sensors for active noise control in acoustic-structural coupled enclosures using structural sensing: robust virtual sensor design.

PubMed

Halim, Dunant; Cheng, Li; Su, Zhongqing

2011-03-01

The work was aimed to develop a robust virtual sensing design methodology for sensing and active control applications of vibro-acoustic systems. The proposed virtual sensor was designed to estimate a broadband acoustic interior sound pressure using structural sensors, with robustness against certain dynamic uncertainties occurring in an acoustic-structural coupled enclosure. A convex combination of Kalman sub-filters was used during the design, accommodating different sets of perturbed dynamic model of the vibro-acoustic enclosure. A minimax optimization problem was set up to determine an optimal convex combination of Kalman sub-filters, ensuring an optimal worst-case virtual sensing performance. The virtual sensing and active noise control performance was numerically investigated on a rectangular panel-cavity system. It was demonstrated that the proposed virtual sensor could accurately estimate the interior sound pressure, particularly the one dominated by cavity-controlled modes, by using a structural sensor. With such a virtual sensing technique, effective active noise control performance was also obtained even for the worst-case dynamics. © 2011 Acoustical Society of America

IPCS user's manual

DOE Office of Scientific and Technical Information (OSTI.GOV)

McGoldrick, P.R.

1980-12-11

The Interprocess Communications System (IPCS) was written to provide a virtual machine upon which the Supervisory Control and Diagnostic System (SCDS) for the Mirror Fusion Test Facility (MFTF) could be built. The hardware upon which the IPCS runs consists of nine minicomputers sharing some common memory.

Improving substructure identification accuracy of shear structures using virtual control system

NASA Astrophysics Data System (ADS)

Zhang, Dongyu; Yang, Yang; Wang, Tingqiang; Li, Hui

2018-02-01

Substructure identification is a powerful tool to identify the parameters of a complex structure. Previously, the authors developed an inductive substructure identification method for shear structures. The identification error analysis showed that the identification accuracy of this method is significantly influenced by the magnitudes of two key structural responses near a certain frequency; if these responses are unfavorable, the method cannot provide accurate estimation results. In this paper, a novel method is proposed to improve the substructure identification accuracy by introducing a virtual control system (VCS) into the structure. A virtual control system is a self-balanced system, which consists of some control devices and a set of self-balanced forces. The self-balanced forces counterbalance the forces that the control devices apply on the structure. The control devices are combined with the structure to form a controlled structure used to replace the original structure in the substructure identification; and the self-balance forces are treated as known external excitations to the controlled structure. By optimally tuning the VCS’s parameters, the dynamic characteristics of the controlled structure can be changed such that the original structural responses become more favorable for the substructure identification and, thus, the identification accuracy is improved. A numerical example of 6-story shear structure is utilized to verify the effectiveness of the VCS based controlled substructure identification method. Finally, shake table tests are conducted on a 3-story structural model to verify the efficacy of the VCS to enhance the identification accuracy of the structural parameters.

Hybrid Feedforward-Feedback Noise Control Using Virtual Sensors

NASA Technical Reports Server (NTRS)

Bean, Jacob; Fuller, Chris; Schiller, Noah

2016-01-01

Several approaches to active noise control using virtual sensors are evaluated for eventual use in an active headrest. Specifically, adaptive feedforward, feedback, and hybrid control structures are compared. Each controller incorporates the traditional filtered-x least mean squares algorithm. The feedback controller is arranged in an internal model configuration to draw comparisons with standard feedforward control theory results. Simulation and experimental results are presented that illustrate each controllers ability to minimize the pressure at both physical and virtual microphone locations. The remote microphone technique is used to obtain pressure estimates at the virtual locations. It is shown that a hybrid controller offers performance benefits over the traditional feedforward and feedback controllers. Stability issues associated with feedback and hybrid controllers are also addressed. Experimental results show that 15-20 dB reduction in broadband disturbances can be achieved by minimizing the measured pressure, whereas 10-15 dB reduction is obtained when minimizing the estimated pressure at a virtual location.

BacNet and Analog/Digital Interfaces of the Building Controls Virtual Testbed

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nouidui, Thierry Stephane; Wetter, Michael; Li, Zhengwei

2011-11-01

This paper gives an overview of recent developments in the Building Controls Virtual Test Bed (BCVTB), a framework for co-simulation and hardware-in-the-loop. First, a general overview of the BCVTB is presented. Second, we describe the BACnet interface, a link which has been implemented to couple BACnet devices to the BCVTB. We present a case study where the interface was used to couple a whole building simulation program to a building control system to assess in real-time the performance of a real building. Third, we present the ADInterfaceMCC, an analog/digital interface that allows a USB-based analog/digital converter to be linked tomore » the BCVTB. In a case study, we show how the link was used to couple the analog/digital converter to a building simulation model for local loop control.« less

Virtual versus face-to-face clinical simulation in relation to student knowledge, anxiety, and self-confidence in maternal-newborn nursing: A randomized controlled trial.

PubMed

Cobbett, Shelley; Snelgrove-Clarke, Erna

2016-10-01

Clinical simulations can provide students with realistic clinical learning environments to increase their knowledge, self-confidence, and decrease their anxiety prior to entering clinical practice settings. To compare the effectiveness of two maternal newborn clinical simulation scenarios; virtual clinical simulation and face-to-face high fidelity manikin simulation. Randomized pretest-posttest design. A public research university in Canada. Fifty-six third year Bachelor of Science in Nursing students. Participants were randomized to either face-to-face or virtual clinical simulation and then to dyads for completion of two clinical simulations. Measures included: (1) Nursing Anxiety and Self-Confidence with Clinical Decision Making Scale (NASC-CDM) (White, 2011), (2) knowledge pretest and post-test related to preeclampsia and group B strep, and (3) Simulation Completion Questionnaire. Before and after each simulation students completed a knowledge test and the NASC-CDM and the Simulation Completion Questionnaire at study completion. There were no statistically significant differences in student knowledge and self-confidence between face-to-face and virtual clinical simulations. Anxiety scores were higher for students in the virtual clinical simulation than for those in the face-to-face simulation. Students' self-reported preference was face-to-face citing the similarities to practicing in a 'real' situation and the immediate debrief. Students not liking the virtual clinical simulation most often cited technological issues as their rationale. Given the equivalency of knowledge and self-confidence when undergraduate nursing students participate in either maternal newborn clinical scenarios of face-to-face or virtual clinical simulation identified in this trial, it is important to take into the consideration costs and benefits/risks of simulation implementation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Failure to Acquire New Semantic Knowledge in Patients With Large Medial Temporal Lobe Lesions

PubMed Central

Bayley, Peter J.; Squire, Larry R.

2009-01-01

We examined new semantic learning in two profoundly amnesic patients (E.P. and G.P.) whose lesions involve virtually the entire medial temporal lobe (MTL) bilaterally. The patients were given five tests of semantic knowledge for information that could only have been acquired after the onset of their amnesia in 1992 and 1987, respectively. Age-matched and education-matched controls (n = 8) were also tested. On tests of recall, E.P. and G.P. each scored 10% correct on a test of 20 easy factual questions (controls = 90%), 2% and 4% correct on 55 questions about news events (controls = 85%), and 0% and 4% correct on a test of 24 famous faces. On three tests of recognition memory for this same material, the patients scored at chance levels. Similarly, the patients were unable to judge whether persons who had been famous for many decades were still living or had died during the past 10 years (E.P. = 53%; G.P. = 50%; controls = 73%; chance = 50%). Lastly, neither patient E.P. nor patient G.P. could draw an accurate floor plan of his current residence, despite having lived there for 10 years and 1 year, respectively. The results demonstrate that the capacity for new semantic learning can be absent, or nearly absent, when there is virtually complete damage to the MTL bilaterally. Accordingly, the results raise the possibility that the acquisition of conscious (declarative) knowledge about the world cannot be supported by structures outside the MTL, even with extended exposure. PMID:15523609

Effect of virtual reality on cognitive dysfunction in patients with brain tumor.

PubMed

Yang, Seoyon; Chun, Min Ho; Son, Yu Ri

2014-12-01

To investigate whether virtual reality (VR) training will help the recovery of cognitive function in brain tumor patients. Thirty-eight brain tumor patients (19 men and 19 women) with cognitive impairment recruited for this study were assigned to either VR group (n=19, IREX system) or control group (n=19). Both VR training (30 minutes a day for 3 times a week) and computer-based cognitive rehabilitation program (30 minutes a day for 2 times) for 4 weeks were given to the VR group. The control group was given only the computer-based cognitive rehabilitation program (30 minutes a day for 5 days a week) for 4 weeks. Computerized neuropsychological tests (CNTs), Korean version of Mini-Mental Status Examination (K-MMSE), and Korean version of Modified Barthel Index (K-MBI) were used to evaluate cognitive function and functional status. The VR group showed improvements in the K-MMSE, visual and auditory continuous performance tests (CPTs), forward and backward digit span tests (DSTs), forward and backward visual span test (VSTs), visual and verbal learning tests, Trail Making Test type A (TMT-A), and K-MBI. The VR group showed significantly (p<0.05) better improvements than the control group in visual and auditory CPTs, backward DST and VST, and TMT-A after treatment. VR training can have beneficial effects on cognitive improvement when it is combined with computer-assisted cognitive rehabilitation. Further randomized controlled studies with large samples according to brain tumor type and location are needed to investigate how VR training improves cognitive impairment.

Effect of Virtual Reality on Cognitive Dysfunction in Patients With Brain Tumor

PubMed Central

Yang, Seoyon; Son, Yu Ri

2014-01-01

Objective To investigate whether virtual reality (VR) training will help the recovery of cognitive function in brain tumor patients. Methods Thirty-eight brain tumor patients (19 men and 19 women) with cognitive impairment recruited for this study were assigned to either VR group (n=19, IREX system) or control group (n=19). Both VR training (30 minutes a day for 3 times a week) and computer-based cognitive rehabilitation program (30 minutes a day for 2 times) for 4 weeks were given to the VR group. The control group was given only the computer-based cognitive rehabilitation program (30 minutes a day for 5 days a week) for 4 weeks. Computerized neuropsychological tests (CNTs), Korean version of Mini-Mental Status Examination (K-MMSE), and Korean version of Modified Barthel Index (K-MBI) were used to evaluate cognitive function and functional status. Results The VR group showed improvements in the K-MMSE, visual and auditory continuous performance tests (CPTs), forward and backward digit span tests (DSTs), forward and backward visual span test (VSTs), visual and verbal learning tests, Trail Making Test type A (TMT-A), and K-MBI. The VR group showed significantly (p<0.05) better improvements than the control group in visual and auditory CPTs, backward DST and VST, and TMT-A after treatment. Conclusion VR training can have beneficial effects on cognitive improvement when it is combined with computer-assisted cognitive rehabilitation. Further randomized controlled studies with large samples according to brain tumor type and location are needed to investigate how VR training improves cognitive impairment. PMID:25566470

Virtual Employment Test Bed Operational Research and Systems Analysis to Test Armaments Designs Early in the Life Cycle

DTIC Science & Technology

2014-06-01

motion capture data used to determine position and orientation of a Soldier’s head, turret and the M2 machine gun • Controlling and acquiring user/weapon...data from the M2 simulation machine gun • Controlling paintball guns used to fire at the GPK during an experimental run • Sending and receiving TCP...Mounted, Armor/Cavalry, Combat Engineers, Field Artillery Cannon Crewmember, or MP duty assignment – Currently M2 .50 Caliber Machine Gun qualified

Integration of the virtual model of a Stewart platform with the avatar of a vehicle in a virtual reality

NASA Astrophysics Data System (ADS)

Herbuś, K.; Ociepka, P.

2016-08-01

The development of methods of computer aided design and engineering allows conducting virtual tests, among others concerning motion simulation of technical means. The paper presents a method of integrating an object in the form of a virtual model of a Stewart platform with an avatar of a vehicle moving in a virtual environment. The area of the problem includes issues related to the problem of fidelity of mapping the work of the analyzed technical mean. The main object of investigations is a 3D model of a Stewart platform, which is a subsystem of the simulator designated for driving learning for disabled persons. The analyzed model of the platform, prepared for motion simulation, was created in the “Motion Simulation” module of a CAD/CAE class system Siemens PLM NX. Whereas the virtual environment, in which the moves the avatar of the passenger car, was elaborated in a VR class system EON Studio. The element integrating both of the mentioned software environments is a developed application that reads information from the virtual reality (VR) concerning the current position of the car avatar. Then, basing on the accepted algorithm, it sends control signals to respective joints of the model of the Stewart platform (CAD).

From Antarctica to space: Use of telepresence and virtual reality in control of remote vehicles

NASA Technical Reports Server (NTRS)

Stoker, Carol; Hine, Butler P., III; Sims, Michael; Rasmussen, Daryl; Hontalas, Phil; Fong, Terrence W.; Steele, Jay; Barch, Don; Andersen, Dale; Miles, Eric

1994-01-01

In the Fall of 1993, NASA Ames deployed a modified Phantom S2 Remotely-Operated underwater Vehicle (ROV) into an ice-covered sea environment near McMurdo Science Station, Antarctica. This deployment was part of the antarctic Space Analog Program, a joint program between NASA and the National Science Foundation to demonstrate technologies relevant for space exploration in realistic field setting in the Antarctic. The goal of the mission was to operationally test the use of telepresence and virtual reality technology in the operator interface to a remote vehicle, while performing a benthic ecology study. The vehicle was operated both locally, from above a dive hole in the ice through which it was launched, and remotely over a satellite communications link from a control room at NASA's Ames Research Center. Local control of the vehicle was accomplished using the standard Phantom control box containing joysticks and switches, with the operator viewing stereo video camera images on a stereo display monitor. Remote control of the vehicle over the satellite link was accomplished using the Virtual Environment Vehicle Interface (VEVI) control software developed at NASA Ames. The remote operator interface included either a stereo display monitor similar to that used locally or a stereo head-mounted head-tracked display. The compressed video signal from the vehicle was transmitted to NASA Ames over a 768 Kbps satellite channel. Another channel was used to provide a bi-directional Internet link to the vehicle control computer through which the command and telemetry signals traveled, along with a bi-directional telephone service. In addition to the live stereo video from the satellite link, the operator could view a computer-generated graphic representation of the underwater terrain, modeled from the vehicle's sensors. The virtual environment contained an animate graphic model of the vehicle which reflected the state of the actual vehicle, along with ancillary information such as the vehicle track, science markers, and locations of video snapshots. The actual vehicle was driven either from within the virtual environment or through a telepresence interface. All vehicle functions could be controlled remotely over the satellite link.

Synthetic hardware performance analysis in virtualized cloud environment for healthcare organization.

PubMed

Tan, Chee-Heng; Teh, Ying-Wah

2013-08-01

The main obstacles in mass adoption of cloud computing for database operations in healthcare organization are the data security and privacy issues. In this paper, it is shown that IT services particularly in hardware performance evaluation in virtual machine can be accomplished effectively without IT personnel gaining access to actual data for diagnostic and remediation purposes. The proposed mechanisms utilized the hypothetical data from TPC-H benchmark, to achieve 2 objectives. First, the underlying hardware performance and consistency is monitored via a control system, which is constructed using TPC-H queries. Second, the mechanism to construct stress-testing scenario is envisaged in the host, using a single or combination of TPC-H queries, so that the resource threshold point can be verified, if the virtual machine is still capable of serving critical transactions at this constraining juncture. This threshold point uses server run queue size as input parameter, and it serves 2 purposes: It provides the boundary threshold to the control system, so that periodic learning of the synthetic data sets for performance evaluation does not reach the host's constraint level. Secondly, when the host undergoes hardware change, stress-testing scenarios are simulated in the host by loading up to this resource threshold level, for subsequent response time verification from real and critical transactions.

Feasibility and reliability of a virtual reality oculus platform to measure sensory integration for postural control in young adults.

PubMed

Lubetzky, Anat V; Kary, Erinn E; Harel, Daphna; Hujsak, Bryan; Perlin, Ken

2018-01-24

Using Unity for the Oculus Development-Kit 2, we have developed an affordable, portable virtual reality platform that targets the visuomotor domain, a missing link in current clinical assessments of postural control. Here, we describe the design and technical development as well as report its feasibility with regards to cybersickness and test-retest reliability in healthy young adults. Our virtual reality paradigm includes two functional scenes ('City' and 'Park') and four moving dots scenes. Twenty-one healthy young adults were tested twice, one to two weeks apart. They completed a simulator sickness questionnaire several times per session. Their postural sway response was recorded from a forceplate underneath their feet while standing on the floor, stability trainers, or a Both Sides Up (BOSU) ball. Sample entropy, postural displacement, velocity, and excursion were calculated and compared between sessions given the visual and surface conditions. Participants reported slight-to-moderate transient side effects. Intra-Class Correlation values mostly ranged from 0.5 to 0.7 for displacement and velocity, were above 0.5 (stability trainer conditions) and above 0.4 (floor mediolateral conditions) for sample entropy, and minimal for excursion. Our novel portable VR platform was found to be feasible and reliable in healthy young adults.

Distributed attitude synchronization of formation flying via consensus-based virtual structure

NASA Astrophysics Data System (ADS)

Cong, Bing-Long; Liu, Xiang-Dong; Chen, Zhen

2011-06-01

This paper presents a general framework for synchronized multiple spacecraft rotations via consensus-based virtual structure. In this framework, attitude control systems for formation spacecrafts and virtual structure are designed separately. Both parametric uncertainty and external disturbance are taken into account. A time-varying sliding mode control (TVSMC) algorithm is designed to improve the robustness of the actual attitude control system. As for the virtual attitude control system, a behavioral consensus algorithm is presented to accomplish the attitude maneuver of the entire formation and guarantee a consistent attitude among the local virtual structure counterparts during the attitude maneuver. A multiple virtual sub-structures (MVSSs) system is introduced to enhance current virtual structure scheme when large amounts of spacecrafts are involved in the formation. The attitude of spacecraft is represented by modified Rodrigues parameter (MRP) for its non-redundancy. Finally, a numerical simulation with three synchronization situations is employed to illustrate the effectiveness of the proposed strategy.

Evaluation of target scores and benchmarks for the traversal task scenario of the Minimally Invasive Surgical Trainer-Virtual Reality (MIST-VR) laparoscopy simulator.

PubMed

Hackethal, A; Immenroth, M; Bürger, T

2006-04-01

The Minimally Invasive Surgical Trainer-Virtual Reality (MIST-VR) simulator is validated for laparoscopy training, but benchmarks and target scores for assessing single tasks are needed. Control data for the MIST-VR traversal task scenario were collected from 61 novices who performed the task 10 times over 3 days (1 h daily). Data were collected on the time taken, error score, economy of movement, and total score. Test differences were analyzed through percentage scores and t-tests for paired samples. Improvement was greatest over tests 1 to 5 (improvement: test(1.2), 38.07%; p = 0.000; test(4.5), 10.66%; p = 0.010): between tests 5 and 10, improvement slowed and scores stabilized. Variation in participants' performance fell steadily over the 10 tests. Trainees should perform at least 10 tests of the traversal task-five to get used to the equipment and task (automation phase; target total score, 95.16) and five to stabilize and consolidate performance (test 10 target total score, 74.11).

[Intraoperative virtual implant planning for volar plate osteosynthesis of distal radius fractures].

PubMed

Franke, J; Vetter, S Y; Reising, K; Herrmann, S; Südkamp, N P; Grützner, P A; von Recum, J

2016-01-01

Digital planning of implants is in most cases conducted prior to surgery. The virtual implant planning system (VIPS) is an application developed for mobile C-arms, which assists the virtual planning of screws close to the joint line during surgery for treatment of distal radius fractures with volar plate osteosynthesis. The aim of this prospective randomized study was to acquire initial clinical experiences and to compare the VIPS method with the conventional technique. The study included 10 patients for primary testing and 30 patients with distal radius fractures of types A3, C1 and C2, divided in 2 groups. In the VIPS group, after placement of the plate and fracture reduction, a virtual 3D model of the plate was matched with the image of the plate from the fluoroscopic acquisition. Next, the length and position of the screws close to the joint line were planned on the virtual plate. The control group was treated with the same implant in the conventional way. Data were collected regarding screw replacement, fluoroscopy and operating room (OR) times. The VIPS group included six A3, one C1 and eight C2 fractures, while the control group consisted of six A3 and nine C2 fractures. Three screws were replaced in the VIPS group and two in the control group (p = 0.24). The mean intraoperative fluoroscopy time of the VIPS group amounted to 2.58 ± 1.38 min, whereas it was 2.12 ± 0.73 min in the control group (p = 0.26). The mean OR time in the VIPS group was 53.3 ± 34.5 minutes and 42.3 ± 8.8 min (p = 0.23) in the control group. The VIPS enables a precise positioning of screws close to joint line in the treatment of distal radius fractures; however, for routine use, further development of the system is necessary.

The trade of virtual water: do property rights matter?

NASA Astrophysics Data System (ADS)

Xu, Ankai

2016-04-01

My paper examines the determinants of the virtual water trade - embodied in the trade of agriculture products - by estimating a structural gravity model. In particular, it tests the relationship between property rights and the export of water-intensive agricultural products based on water footprint data in Mekonnen and Hoekstra (2011, 2012). Using two different measures of property rights protection, I show that countries with weaker property rights have an apparent comparative advantage in the trade of water-intensive products. After controlling for the economic size, natural resource endowments, and possible effects of reverse causality, the trade flow of virtual water is negatively and significantly correlated with the property rights index of the exporting country. Holding other factors constant, one point increase in the property rights index of a country is associated with a 24% - 36% decrease in its virtual water export, whereas a 1% increase in the natural resource protection index of a country is associated with a 16% decrease in its virtual water export. This paper is the first empirical work that tests the relationship between property rights and trade of water-intensive products, offering a new perceptive in the debate of virtual water trade. The findings provide a possible explanation on the paradoxical evidence that some countries with scarce water resources export water-intensive products. The result is important not only in terms of its theoretical relevance, but also its policy implications. As prescribed by the model of trade and property rights, when countries with weaker property rights open to international trade, they are more likely to over-exploit and thus expedite the depletion of natural resources.

Real enough: using virtual public speaking environments to evoke feelings and behaviors targeted in stuttering assessment and treatment.

PubMed

Brundage, Shelley B; Hancock, Adrienne B

2015-05-01

Virtual reality environments (VREs) are computer-generated, 3-dimensional worlds that allow users to experience situations similar to those encountered in the real world. The purpose of this study was to investigate VREs for potential use in assessing and treating persons who stutter (PWS) by determining the extent to which PWS's affective, behavioral, and cognitive measures in a VRE correlate with those same measures in a similar live environment. Ten PWS delivered speeches-first to a live audience and, on another day, to 2 virtual audiences (neutral and challenging audiences). Participants completed standard tests of communication apprehension and confidence prior to each condition, and frequency of stuttering was measured during each speech. Correlational analyses revealed significant, positive correlations between virtual and live conditions for affective and cognitive measures as well as for frequency of stuttering. These findings suggest that virtual public speaking environments engender affective, behavioral, and cognitive reactions in PWS that correspond to those experienced in the real world. Therefore, the authentic, safe, and controlled environments provided by VREs may be useful for stuttering assessment and treatment.

Ownership and Agency of an Independent Supernumerary Hand Induced by an Imitation Brain-Computer Interface.

PubMed

Bashford, Luke; Mehring, Carsten

2016-01-01

To study body ownership and control, illusions that elicit these feelings in non-body objects are widely used. Classically introduced with the Rubber Hand Illusion, these illusions have been replicated more recently in virtual reality and by using brain-computer interfaces. Traditionally these illusions investigate the replacement of a body part by an artificial counterpart, however as brain-computer interface research develops it offers us the possibility to explore the case where non-body objects are controlled in addition to movements of our own limbs. Therefore we propose a new illusion designed to test the feeling of ownership and control of an independent supernumerary hand. Subjects are under the impression they control a virtual reality hand via a brain-computer interface, but in reality there is no causal connection between brain activity and virtual hand movement but correct movements are observed with 80% probability. These imitation brain-computer interface trials are interspersed with movements in both the subjects' real hands, which are in view throughout the experiment. We show that subjects develop strong feelings of ownership and control over the third hand, despite only receiving visual feedback with no causal link to the actual brain signals. Our illusion is crucially different from previously reported studies as we demonstrate independent ownership and control of the third hand without loss of ownership in the real hands.

Robust controller designs for second-order dynamic system: A virtual passive approach

NASA Technical Reports Server (NTRS)

Juang, Jer-Nan; Phan, Minh

1990-01-01

A robust controller design is presented for second-order dynamic systems. The controller is model-independent and itself is a virtual second-order dynamic system. Conditions on actuator and sensor placements are identified for controller designs that guarantee overall closed-loop stability. The dynamic controller can be viewed as a virtual passive damping system that serves to stabilize the actual dynamic system. The control gains are interpreted as virtual mass, spring, and dashpot elements that play the same roles as actual physical elements in stability analysis. Position, velocity, and acceleration feedback are considered. Simple examples are provided to illustrate the physical meaning of this controller design.

Can Active Navigation Be as Good as Driving? A Comparison of Spatial Memory in Drivers and Backseat Drivers

ERIC Educational Resources Information Center

von Stulpnagel, Rul; Steffens, Melanie C.

2012-01-01

When driving a vehicle, either the driver or a passenger (henceforth: backseat driver) may be responsible for navigation. Research on active navigation, primarily addressed in virtual environments, suggests that controlling navigation is more central for spatial learning than controlling movement. To test this assumption in a real-world scenario,…

Differential Sensitivity Between a Virtual Reality Balance Module and Clinically Used Concussion Balance Modalities.

PubMed

Teel, Elizabeth F; Gay, Michael R; Arnett, Peter A; Slobounov, Semyon M

2016-03-01

Balance assessments are part of the recommended clinical concussion evaluation, along with computerized neuropsychological testing and self-reported symptoms checklists. New technology has allowed for the creation of virtual reality (VR) balance assessments to be used in concussion care, but there is little information on the sensitivity and specificity of these evaluations. The purpose of this study is to establish the sensitivity and specificity of a VR balance module for detecting lingering balance deficits clinical concussion care. Retrospective case-control study. Institutional research laboratory. Normal controls (n = 94) and concussed participants (n = 27). All participants completed a VR balance assessment paradigm. Concussed participants were diagnosed by a Certified Athletic Trainer or physician (with 48 hours postinjury) and tested in the laboratory between 7 and 10 days postinjury. Receiver operating characteristic curves were performed to establish the VR module's sensitivity and specificity for detecting lingering balance deficits. Final balance score. For the VR balance module, a cutoff score of 8.25 was established to maximize sensitivity at 85.7% and specificity at 87.8%. The VR balance module has high sensitivity and specificity for detecting subacute balance deficits after concussive injury. The VR balance has a high subacute sensitivity and specificity as a stand-alone balance assessment tool and may detect ongoing balance deficits not readily detectable by the Balance Error Scoring System or Sensory Organization Test. Virtual reality balance modules may be a beneficial addition to the current clinical concussion diagnostic battery.

Isolated core vs. superficial cooling effects on virtual maze navigation.

PubMed

Payne, Jennifer; Cheung, Stephen S

2007-07-01

Cold impairs cognitive performance and is a common occurrence in many survival situations. Altered behavior patterns due to impaired navigation abilities in cold environments are potential problems in lost-person situations. We investigated the separate effects of low core temperature and superficial cooling on a spatially demanding virtual navigation task. There were 12 healthy men who were passively cooled via 15 degrees C water immersion to a core temperature of 36.0 degrees C, then transferred to a warm (40 degrees C) water bath to eliminate superficial shivering while completing a series of 20 virtual computer mazes. In a control condition, subjects rested in a thermoneutral (approximately 35 degrees C) bath for a time-matched period before being transferred to a warm bath for testing. Superficial cooling and distraction were achieved by whole-body immersion in 35 degree water for a time-matched period, followed by lower leg immersion in 10 degree C water for the duration of the navigational tests. Mean completion time and mean error scores for the mazes were not significantly different (p > 0.05) across the core cooling (16.59 +/- 11.54 s, 0.91 +/- 1.86 errors), control (15.40 +/- 8.85 s, 0.82 +/- 1.76 errors), and superficial cooling (15.19 +/- 7.80 s, 0.77 +/- 1.40 errors) conditions. Separately reducing core temperature or increasing cold sensation in the lower extremities did not influence performance on virtual computer mazes, suggesting that navigation is more resistive to cooling than other, simpler cognitive tasks. Further research is warranted to explore navigational ability at progressively lower core and skin temperatures, and in different populations.

Acute Effect of Static Stretching on Lower Limb Movement Performance by Using STABL Virtual Reality System.

PubMed

Ameer, Mariam A; Muaidi, Qassim I

2017-07-17

The effect of acute static stretch (ASS) on the lower limb RT has been recently questioned to decrease the risk of falling and injuries in situations requiring a rapid reaction, as in the cases of balance disturbance. The main purpose of this study was to detect the effect of ASS on the lower limb RT by using virtual reality device. Two Group Control Group design. Research laboratory. The control and experimental groups were formed randomly from sixty female university students. Each participant in the experimental group was tested before and after ASS for the quadriceps, hamstrings and planter flexor muscles, and compared with the control group with warming-up exercise only. The stretching program involved warming-up in the form of circular running inside the lab for 5 minutes followed by stretching of each muscle group thrice, to the limit of discomfort of 45 s, with resting period of 15s between stretches. The measurements included the RT of the dominant lower extremity by using the dynamic stability program, STABL Virtual Reality System (Model No. DIZ 2709, Motek Medical and Force Link Merged Co., Amsterdam). There was statistically significant reduction (F = 162, P= .00) in post-test RT between the two groups, and significant decrease in RT after stretching, in the experimental group (7.5%) (P= .00). ASS of the lower limb muscles tends to decrease the lower limb RT and improve movement performance.

The impact of constructive feedback on training in gastrointestinal endoscopy using high-fidelity Virtual-Reality simulation: a randomised controlled trial.

PubMed

Kruglikova, Irina; Grantcharov, Teodor P; Drewes, Asbjorn M; Funch-Jensen, Peter

2010-02-01

Recently, virtual reality computer simulators have been used to enhance traditional endoscopy teaching. Previous studies have demonstrated construct validity of these systems and transfer of virtual skills to the operating room. However, to date no simulator-training curricula have been designed and there is very little evidence on the impact of external feedback on acquisition of endoscopic skills. The aim of the present study was to assess the impact of external feedback on the learning curves on a VR colonoscopy simulator using inexperienced trainees. 22 trainees, without colonoscopy experience were randomised to a group which received structured feedback provided by an experienced supervisor and a controlled group. All participants performed 15 repetitions of task 3 from the Introduction colonoscopy module of the Accu Touch Endoscopy simulator. Retention/transfer tests on simulator were performed 4-6 weeks after the last repetition. The proficiency levels were based on the performance of eight experienced colonoscopists. All subjects were able to complete the procedure on the simulator. There were no perforations in the feedback group versus seven in the non-feedback group. Subjects in the feedback group reached expert proficiency levels in percentage of mucosa visualised and time to reach the caecum significantly faster compared with the control group. None of the groups demonstrated significant degradation of performance in simulator retention/transfer tests. Concurrent feedback given by supervisor concur an advantage in acquisition of basic colonoscopy skills and achieving of proficiency level as compared to independent training.

[Memory assessment by means of virtual reality: its present and future].

PubMed

Diaz-Orueta, Unai; Climent, Gema; Cardas-Ibanez, Jaione; Alonso, Laura; Olmo-Osa, Juan; Tirapu-Ustarroz, Javier

2016-01-16

The human memory is a complex cognitive system whose close relationship with executive functions implies that, in many occasions, a mnemonic deficit comprises difficulties to operate with correctly stored contents. Traditional memory tests, more focused in the information storage than in its processing, may be poorly sensitive both to subjects' daily life functioning and to changes originated by rehabilitation programs. In memory assessment, there is plenty evidence with regards to the need of improving it by means of tests which offer a higher ecological validity, with information that may be presented in various sensorial modalities and produced in a simultaneous way. Virtual reality reproduces three-dimensional environments with which the patient interacts in a dynamic way, with a sense of immersion in the environment similar to the presence and exposure to a real environment, and in which presentation of such stimuli, distractors and other variables may be systematically controlled. The current review aims to go deeply into the trajectory of neuropsychological assessment of memory based in virtual reality environments, making a tour through existing tests designed for assessing learning, prospective, episodic and spatial memory, as well as the most recent attempts to perform a comprehensive evaluation of all memory components.

Planning Image-Based Measurements in Wind Tunnels by Virtual Imaging

NASA Technical Reports Server (NTRS)

Kushner, Laura Kathryn; Schairer, Edward T.

2011-01-01

Virtual imaging is routinely used at NASA Ames Research Center to plan the placement of cameras and light sources for image-based measurements in production wind tunnel tests. Virtual imaging allows users to quickly and comprehensively model a given test situation, well before the test occurs, in order to verify that all optical testing requirements will be met. It allows optimization of the placement of cameras and light sources and leads to faster set-up times, thereby decreasing tunnel occupancy costs. This paper describes how virtual imaging was used to plan optical measurements for three tests in production wind tunnels at NASA Ames.

Motor performance of individuals with cerebral palsy in a virtual game using a mobile phone.

PubMed

de Paula, Juliana Nobre; de Mello Monteiro, Carlos Bandeira; da Silva, Talita Dias; Capelini, Camila Miliani; de Menezes, Lilian Del Cielo; Massetti, Thais; Tonks, James; Watson, Suzanna; Nicolai Ré, Alessandro Hervaldo

2017-11-01

Cerebral palsy (CP) is a permanent disorder of movement, muscle tone or posture that is caused by damage to the immature and developing brain. Research has shown that Virtual Reality (VR) technology can be used in rehabilitation to support the acquisition of motor skills and the achievement of functional tasks. The aim of this study was to explore for improvements in the performance of individuals with CP with practice in the use of a virtual game on a mobile phone and to compare their performance with that of the control group. Twenty-five individuals with CP were matched for age and sex with twenty-five, typically developing individuals. Participants were asked to complete a VR maze task as fast as possible on a mobile phone. All participants performed 20 repetitions in the acquisition phase, five repetitions for retention and five more repetitions for transfer tests, in order to evaluate motor learning from the task. The CP group improved their performance in the acquisition phase and maintained the performance, which was shown by the retention test; in addition, they were able to transfer the performance acquired in an opposite maze path. The CP group had longer task-execution compared to the control group for all phases of the study. Individuals with cerebral palsy were able to learn a virtual reality game (maze task) using a mobile phone, and despite their differences from the control group, this kind of device offers new possibilities for use to improve function. Implications for rehabilitation A virtual game on a mobile phone can enable individuals with Cerebral Palsy (CP) to improve performance. This illustrates the potential for use of mobile phone games to improve function. Individuals with CP had poorer performance than individuals without CP, but they demonstrated immediate improvements from using a mobile phone device. Individuals with CP were able to transfer their skills to a similar task indicating that they were able to learn these motor skills by using a mobile phone game.

The Effects of Virtual Versus Physical Lab Manipulatives on Inquiry Skill Acquisition and Conceptual Understanding of Density

NASA Astrophysics Data System (ADS)

Brinson, James R.

The current study compared the effects of virtual versus physical laboratory manipulatives on 84 undergraduate non-science majors' (a) conceptual understanding of density and (b) density-related inquiry skill acquisition. A pre-post comparison study design was used, which incorporated all components of an inquiry-guided classroom, except experimental mode, and which controlled for curriculum, instructor, instructional method, time spent on task, and availability of reference resources. Participants were randomly assigned to either a physical or virtual lab group. Pre- and post-assessments of conceptual understanding and inquiry skills were administered to both groups. Paired-samples t tests revealed a significant mean percent correct score increase for conceptual understanding in both the physical lab group (M = .103, SD = .168), t(38) = -3.82, p < .001, r = .53, two-tailed, and the virtual lab group (M = .084, SD = .177), t(44) = -3.20, p = .003, r = .43, two-tailed. However, a one-way ANCOVA (using pretest scores as the covariate) revealed that the main effect of lab group on conceptual learning gains was not significant, F(1, 81) = 0.081, p = .776, two-tailed. An omnibus test of model coefficients within hierarchical logistic regression revealed that a correct response on inquiry pretest scores was not a significant predictor of a correct post-test response, chi 2(1, N = 84) = 1.68, p = .195, and that when lab mode was added to the model, it did not significantly increase the model's predictive ability, chi2(2, N = 84) = 1.95, p = .377. Thus, the data in the current study revealed no significant difference in the effect of physical versus virtual manipulatives when used to teach conceptual understanding and inquiry skills related to density.

Modulation of walking speed by changing optic flow in persons with stroke

PubMed Central

Lamontagne, Anouk; Fung, Joyce; McFadyen, Bradford J; Faubert, Jocelyn

2007-01-01

Background Walking speed, which is often reduced after stroke, can be influenced by the perception of optic flow (OF) speed. The present study aims to: 1) compare the modulation of walking speed in response to OF speed changes between persons with stroke and healthy controls and 2) investigate whether virtual environments (VE) manipulating OF speed can be used to promote volitional changes in walking speed post stroke. Methods Twelve persons with stroke and 12 healthy individuals walked on a self-paced treadmill while viewing a virtual corridor in a helmet-mounted display. Two experiments were carried out on the same day. In experiment 1, the speed of an expanding OF was varied sinusoidally at 0.017 Hz (sine duration = 60 s), from 0 to 2 times the subject's comfortable walking speed, for a total duration of 5 minutes. In experiment 2, subjects were exposed to expanding OFs at discrete speeds that ranged from 0.25 to 2 times their comfortable speed. Each test trial was paired with a control trial performed at comfortable speed with matching OF. For each of the test trials, subjects were instructed to walk the distance within the same time as during the immediately preceding control trial. VEs were controlled by the CAREN-2 system (Motek). Instantaneous changes in gait speed (experiment 1) and the ratio of speed changes in the test trial over the control trial (experiment 2) were contrasted between the two groups of subjects. Results When OF speed was changing continuously (experiment 1), an out-of-phase modulation was observed in the gait speed of healthy subjects, such that slower OFs induced faster walking speeds, and vice versa. Persons with stroke displayed weaker (p < 0.05, T-test) correlation coefficients between gait speed and OF speed, due to less pronounced changes and an altered phasing of gait speed modulation. When OF speed was manipulated discretely (experiment 2), a negative linear relationship was generally observed between the test-control ratio of gait speed and OF speed in healthy and stroke individuals. The slope of this relationship was similar between the stroke and healthy groups (p > 0.05, T-test). Conclusion Stroke affects the modulation of gait speed in response to changes in the perception of movement through different OF speeds. Nevertheless, the preservation of even a modest modulation enabled the persons with stroke to increase walking speed when presented with slower OFs. Manipulation of OF speed using virtual reality technology could be implemented in a gait rehabilitation intervention to promote faster walking speeds after stroke. PMID:17594501

Using virtual instruments to develop an actuator-based hardware-in-the-loop simulation test-bed for autopilot of unmanned aerial vehicle

NASA Astrophysics Data System (ADS)

Sun, Yun-Ping; Ju, Jiun-Yan; Liang, Yen-Chu

2008-12-01

Since the unmanned aerial vehicles (UAVs) bring forth many innovative applications in scientific, civilian, and military fields, the development of UAVs is rapidly growing every year. The on-board autopilot that reliably performs attitude and guidance control is a vital part for out-of-sight flights. However, the control law in autopilot is designed according to a simplified plant model in which the dynamics of real hardware are usually not taken into consideration. It is a necessity to develop a test-bed including real servos to make real-time control experiments for prototype autopilots, so called hardware-in-the-loop (HIL) simulation. In this paper on the basis of the graphical application software LabVIEW, the real-time HIL simulation system is realized efficiently by the virtual instrumentation approach. The proportional-integral-derivative (PID) controller in autopilot for the pitch angle control loop is experimentally determined by the classical Ziegler-Nichols tuning rule and exhibits good transient and steady-state response in real-time HIL simulation. From the results the differences between numerical simulation and real-time HIL simulation are also clearly presented. The effectiveness of HIL simulation for UAV autopilot design is definitely confirmed

ISMCR 1994: Topical Workshop on Virtual Reality. Proceedings of the Fourth International Symposium on Measurement and Control in Robotics

NASA Technical Reports Server (NTRS)

1994-01-01

This symposium on measurement and control in robotics included sessions on: (1) rendering, including tactile perception and applied virtual reality; (2) applications in simulated medical procedures and telerobotics; (3) tracking sensors in a virtual environment; (4) displays for virtual reality applications; (5) sensory feedback including a virtual environment application with partial gravity simulation; and (6) applications in education, entertainment, technical writing, and animation.

Differential impact of partial cortical blindness on gaze strategies when sitting and walking - an immersive virtual reality study

PubMed Central

Iorizzo, Dana B.; Riley, Meghan E.; Hayhoe, Mary; Huxlin, Krystel R.

2011-01-01

The present experiments aimed to characterize the visual performance of subjects with long-standing, unilateral cortical blindness when walking in a naturalistic, virtual environment. Under static, seated testing conditions, cortically blind subjects are known to exhibit compensatory eye movement strategies. However, they still complain of significant impairment in visual detection during navigation. To assess whether this is due to a change in compensatory eye movement strategy between sitting and walking, we measured eye and head movements in subjects asked to detect peripherally-presented, moving basketballs. When seated, cortically blind subjects detected ~80% of balls, while controls detected almost all balls. Seated blind subjects did not make larger head movements than controls, but they consistently biased their fixation distribution towards their blind hemifield. When walking, head movements were similar in the two groups, but the fixation bias decreased to the point that fixation distribution in cortically blind subjects became similar to that in controls - with one major exception: at the time of basketball appearance, walking controls looked primarily at the far ground, in upper quadrants of the virtual field of view; cortically blind subjects looked significantly more at the near ground, in lower quadrants of the virtual field. Cortically blind subjects detected only 58% of the balls when walking while controls detected ~90%. Thus, the adaptive gaze strategies adopted by cortically blind individuals as a compensation for their visual loss are strongest and most effective when seated and stationary. Walking significantly alters these gaze strategies in a way that seems to favor walking performance, but impairs peripheral target detection. It is possible that this impairment underlies the experienced difficulty of those with cortical blindness when navigating in real life. PMID:21414339

Differential impact of partial cortical blindness on gaze strategies when sitting and walking - an immersive virtual reality study.

PubMed

Iorizzo, Dana B; Riley, Meghan E; Hayhoe, Mary; Huxlin, Krystel R

2011-05-25

The present experiments aimed to characterize the visual performance of subjects with long-standing, unilateral cortical blindness when walking in a naturalistic, virtual environment. Under static, seated testing conditions, cortically blind subjects are known to exhibit compensatory eye movement strategies. However, they still complain of significant impairment in visual detection during navigation. To assess whether this is due to a change in compensatory eye movement strategy between sitting and walking, we measured eye and head movements in subjects asked to detect peripherally-presented, moving basketballs. When seated, cortically blind subjects detected ∼80% of balls, while controls detected almost all balls. Seated blind subjects did not make larger head movements than controls, but they consistently biased their fixation distribution towards their blind hemifield. When walking, head movements were similar in the two groups, but the fixation bias decreased to the point that fixation distribution in cortically blind subjects became similar to that in controls - with one major exception: at the time of basketball appearance, walking controls looked primarily at the far ground, in upper quadrants of the virtual field of view; cortically blind subjects looked significantly more at the near ground, in lower quadrants of the virtual field. Cortically blind subjects detected only 58% of the balls when walking while controls detected ∼90%. Thus, the adaptive gaze strategies adopted by cortically blind individuals as a compensation for their visual loss are strongest and most effective when seated and stationary. Walking significantly alters these gaze strategies in a way that seems to favor walking performance, but impairs peripheral target detection. It is possible that this impairment underlies the experienced difficulty of those with cortical blindness when navigating in real life. Copyright © 2011 Elsevier Ltd. All rights reserved.

Asymmetric training using virtual reality reflection equipment and the enhancement of upper limb function in stroke patients: a randomized controlled trial.

PubMed

Lee, DongJin; Lee, MyungMo; Lee, KyoungJin; Song, ChangHo

2014-07-01

Asymmetric movements with both hands contributed to the improvement of spatially coupled motion. Thus, the aim of this study was to investigate the effects of an asymmetric training program using virtual reality reflection equipment on upper limb function in stroke patients. Twenty-four stroke patients were randomly allocated to an experimental group (n=12) or a control group (n=12). Both groups participated in conventional physical therapy for 2×30 min/d, 5 d/wk, for 4 weeks. The experimental group also participated in an asymmetric training program using virtual reality reflection equipment, and the control group participated in a symmetric training program. Both asymmetric and symmetric programs were conducted for 30 min/d, 5 d/wk, for 4 weeks. To compare upper limb function before and after intervention, the Fugl-Meyer Assessment (FMA), the Box and Block Test (BBT), grip strength, range of motion (ROM), and spasticity were assessed. Both groups showed significant increases in upper limb function, excepting spasticity, after intervention (P<.05, 1-way repeated-measures analysis of variance [ANOVA]). A significant group-time interaction was demonstrated only for shoulder/elbow/wrist items of FMA, BBT, grip strength, and ROM of wrist flexion, extension, and ulnar deviation (P<.05, 2-way repeated-measures ANOVA). This study confirms that the asymmetric training program using virtual reality reflection equipment is an effective intervention method for improving upper limb function in stroke patients. We consider that an additional study based on a program using virtual reflection, which is more functional than performing simple tasks, and consisting of tasks relevant to the activities of daily living be conducted. Copyright © 2014 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Extending MAM5 Meta-Model and JaCalIV E Framework to Integrate Smart Devices from Real Environments.

PubMed

Rincon, J A; Poza-Lujan, Jose-Luis; Julian, V; Posadas-Yagüe, Juan-Luis; Carrascosa, C

2016-01-01

This paper presents the extension of a meta-model (MAM5) and a framework based on the model (JaCalIVE) for developing intelligent virtual environments. The goal of this extension is to develop augmented mirror worlds that represent a real and virtual world coupled, so that the virtual world not only reflects the real one, but also complements it. A new component called a smart resource artifact, that enables modelling and developing devices to access the real physical world, and a human in the loop agent to place a human in the system have been included in the meta-model and framework. The proposed extension of MAM5 has been tested by simulating a light control system where agents can access both virtual and real sensor/actuators through the smart resources developed. The results show that the use of real environment interactive elements (smart resource artifacts) in agent-based simulations allows to minimize the error between simulated and real system.

Extending MAM5 Meta-Model and JaCalIV E Framework to Integrate Smart Devices from Real Environments

PubMed Central

2016-01-01

This paper presents the extension of a meta-model (MAM5) and a framework based on the model (JaCalIVE) for developing intelligent virtual environments. The goal of this extension is to develop augmented mirror worlds that represent a real and virtual world coupled, so that the virtual world not only reflects the real one, but also complements it. A new component called a smart resource artifact, that enables modelling and developing devices to access the real physical world, and a human in the loop agent to place a human in the system have been included in the meta-model and framework. The proposed extension of MAM5 has been tested by simulating a light control system where agents can access both virtual and real sensor/actuators through the smart resources developed. The results show that the use of real environment interactive elements (smart resource artifacts) in agent-based simulations allows to minimize the error between simulated and real system. PMID:26926691

Childhood trauma, psychosis liability and social stress reactivity: a virtual reality study.

PubMed

Veling, W; Counotte, J; Pot-Kolder, R; van Os, J; van der Gaag, M

2016-12-01

Childhood trauma is associated with higher risk for mental disorders, including psychosis. Heightened sensitivity to social stress may be a mechanism. This virtual reality study tested the effect of childhood trauma on level of paranoid ideations and distress in response to social stress, in interaction with psychosis liability and level of social stress exposure. Seventy-five individuals with higher psychosis liability (55 with recent onset psychotic disorder and 20 at ultra-high risk for psychosis) and 95 individuals with lower psychosis liability (42 siblings and 53 controls) were exposed to a virtual café in five experiments with 0-3 social stressors (crowded, other ethnicity and hostility). Paranoid ideation was measured after each experiment. Subjective distress was self-rated before and after experiments. Multilevel random regression analyses were used to test main effects of childhood trauma and interaction effects. Childhood trauma was more prevalent in individuals with higher psychosis liability, and was associated with higher level of (subclinical) psychotic and affective symptoms. Individuals with a history of childhood trauma responded with more subjective distress to virtual social stress exposures. The effects of childhood trauma on paranoia and subjective distress were significantly stronger when the number of virtual environmental stressors increased. Higher psychosis liability increased the effect of childhood trauma on peak subjective distress and stress reactivity during experiments. Childhood trauma is associated with heightened social stress sensitivity and may contribute to psychotic and affective dysregulation later in life, through a sensitized paranoid and stress response to social stressors.

Virtual reality anatomy: is it comparable with traditional methods in the teaching of human forearm musculoskeletal anatomy?

PubMed

Codd, Anthony M; Choudhury, Bipasha

2011-01-01

The use of cadavers to teach anatomy is well established, but limitations with this approach have led to the introduction of alternative teaching methods. One such method is the use of three-dimensional virtual reality computer models. An interactive, three-dimensional computer model of human forearm anterior compartment musculoskeletal anatomy was produced using the open source 3D imaging program "Blender." The aim was to evaluate the use of 3D virtual reality when compared with traditional anatomy teaching methods. Three groups were identified from the University of Manchester second year Human Anatomy Research Skills Module class: a "control" group (no prior knowledge of forearm anatomy), a "traditional methods" group (taught using dissection and textbooks), and a "model" group (taught solely using e-resource). The groups were assessed on anatomy of the forearm by a ten question practical examination. ANOVA analysis showed the model group mean test score to be significantly higher than the control group (mean 7.25 vs. 1.46, P < 0.001) and not significantly different to the traditional methods group (mean 6.87, P > 0.5). Feedback from all users of the e-resource was positive. Virtual reality anatomy learning can be used to compliment traditional teaching methods effectively. Copyright © 2011 American Association of Anatomists.

The effects of training by virtual reality or gym ball on pelvic floor muscle strength in postmenopausal women: a randomized controlled trial.

PubMed

Martinho, Natalia M; Silva, Valéria R; Marques, Joseane; Carvalho, Leonardo C; Iunes, Denise H; Botelho, Simone

2016-03-22

To evaluate the effectiveness of abdominopelvic training by virtual reality compared to pelvic floor muscle training (PFMT) using a gym ball (a previously tested and efficient protocol) on postmenopausal women's pelvic floor muscle (PFM) strength. A randomized controlled trial was conducted with 60 postmenopausal women, randomly allocated into two groups: Abdominopelvic training by virtual reality - APT_VR (n=30) and PFMT using a gym ball - PFMT_GB (n=30). Both types of training were supervised by the same physical therapist, during 10 sessions each, for 30 minutes. The participants' PFM strength was evaluated by digital palpation and vaginal dynamometry, considering three different parameters: maximum strength, average strength and endurance. An intention-to-treat approach was used to analyze the participants according to original groups. No significant between-group differences were observed in most analyzed parameters. The outcome endurance was higher in the APT_VR group (p=0.003; effect size=0.89; mean difference=1.37; 95% CI=0.46 to 2.28). Both protocols have improved the overall PFM strength, suggesting that both are equally beneficial and can be used in clinical practice. Muscle endurance was higher in patients who trained using virtual reality.

The effects of training by virtual reality or gym ball on pelvic floor muscle strength in postmenopausal women: a randomized controlled trial

PubMed Central

Martinho, Natalia M.; Silva, Valéria R.; Marques, Joseane; Carvalho, Leonardo C.; Iunes, Denise H.; Botelho, Simone

2016-01-01

ABSTRACT Objective To evaluate the effectiveness of abdominopelvic training by virtual reality compared to pelvic floor muscle training (PFMT) using a gym ball (a previously tested and efficient protocol) on postmenopausal women’s pelvic floor muscle (PFM) strength. Method A randomized controlled trial was conducted with 60 postmenopausal women, randomly allocated into two groups: Abdominopelvic training by virtual reality – APT_VR (n=30) and PFMT using a gym ball – PFMT_GB (n=30). Both types of training were supervised by the same physical therapist, during 10 sessions each, for 30 minutes. The participants’ PFM strength was evaluated by digital palpation and vaginal dynamometry, considering three different parameters: maximum strength, average strength and endurance. An intention-to-treat approach was used to analyze the participants according to original groups. Results No significant between-group differences were observed in most analyzed parameters. The outcome endurance was higher in the APT_VR group (p=0.003; effect size=0.89; mean difference=1.37; 95% CI=0.46 to 2.28). Conclusion Both protocols have improved the overall PFM strength, suggesting that both are equally beneficial and can be used in clinical practice. Muscle endurance was higher in patients who trained using virtual reality. PMID:27437716

Evolving a Neural Olfactorimotor System in Virtual and Real Olfactory Environments

PubMed Central

Rhodes, Paul A.; Anderson, Todd O.

2012-01-01

To provide a platform to enable the study of simulated olfactory circuitry in context, we have integrated a simulated neural olfactorimotor system with a virtual world which simulates both computational fluid dynamics as well as a robotic agent capable of exploring the simulated plumes. A number of the elements which we developed for this purpose have not, to our knowledge, been previously assembled into an integrated system, including: control of a simulated agent by a neural olfactorimotor system; continuous interaction between the simulated robot and the virtual plume; the inclusion of multiple distinct odorant plumes and background odor; the systematic use of artificial evolution driven by olfactorimotor performance (e.g., time to locate a plume source) to specify parameter values; the incorporation of the realities of an imperfect physical robot using a hybrid model where a physical robot encounters a simulated plume. We close by describing ongoing work toward engineering a high dimensional, reversible, low power electronic olfactory sensor which will allow olfactorimotor neural circuitry evolved in the virtual world to control an autonomous olfactory robot in the physical world. The platform described here is intended to better test theories of olfactory circuit function, as well as provide robust odor source localization in realistic environments. PMID:23112772

Virtual reality intervention for older women with breast cancer.

PubMed

Schneider, Susan M; Ellis, Mathew; Coombs, William T; Shonkwiler, Erin L; Folsom, Linda C

2003-06-01

This study examined the effects of a virtual reality distraction intervention on chemotherapy-related symptom distress levels in 16 women aged 50 and older. A cross-over design was used to answer the following research questions: (1) Is virtual reality an effective distraction intervention for reducing chemotherapy-related symptom distress levels in older women with breast cancer? (2) Does virtual reality have a lasting effect? Chemotherapy treatments are intensive and difficult to endure. One way to cope with chemotherapy-related symptom distress is through the use of distraction. For this study, a head-mounted display (Sony PC Glasstron PLM - S700) was used to display encompassing images and block competing stimuli during chemotherapy infusions. The Symptom Distress Scale (SDS), Revised Piper Fatigue Scale (PFS), and the State Anxiety Inventory (SAI) were used to measure symptom distress. For two matched chemotherapy treatments, one pre-test and two post-test measures were employed. Participants were randomly assigned to receive the VR distraction intervention during one chemotherapy treatment and received no distraction intervention (control condition) during an alternate chemotherapy treatment. Analysis using paired t-tests demonstrated a significant decrease in the SAI (p = 0.10) scores immediately following chemotherapy treatments when participants used VR. No significant changes were found in SDS or PFS values. There was a consistent trend toward improved symptoms on all measures 48 h following completion of chemotherapy. Evaluation of the intervention indicated that women thought the head mounted device was easy to use, they experienced no cybersickness, and 100% would use VR again.

Virtualization of System of Systems Test and Evaluation

DTIC Science & Technology

2012-06-04

computers and is the primary enabler for virtualization. 2. Virtualization System Elements Parmalee, Peterson , Tillman, & Hatfield (1972) outlined the...The work of Abu-Taieh and El Sheikh, based on the work of Balci (1994, 1995), and Balci et al. ( 1996 ), seeks to organize types of tests and to...and testing. In A. Dasso & A. Funes (Eds.), Verification, validation, and testing in software engineering (pp. 155–184). Hershey , PA: Idea Group

Robotic and Virtual Reality BCIs Using Spatial Tactile and Auditory Oddball Paradigms.

PubMed

Rutkowski, Tomasz M

2016-01-01

The paper reviews nine robotic and virtual reality (VR) brain-computer interface (BCI) projects developed by the author, in collaboration with his graduate students, within the BCI-lab research group during its association with University of Tsukuba, Japan. The nine novel approaches are discussed in applications to direct brain-robot and brain-virtual-reality-agent control interfaces using tactile and auditory BCI technologies. The BCI user intentions are decoded from the brainwaves in realtime using a non-invasive electroencephalography (EEG) and they are translated to a symbiotic robot or virtual reality agent thought-based only control. A communication protocol between the BCI output and the robot or the virtual environment is realized in a symbiotic communication scenario using an user datagram protocol (UDP), which constitutes an internet of things (IoT) control scenario. Results obtained from healthy users reproducing simple brain-robot and brain-virtual-agent control tasks in online experiments support the research goal of a possibility to interact with robotic devices and virtual reality agents using symbiotic thought-based BCI technologies. An offline BCI classification accuracy boosting method, using a previously proposed information geometry derived approach, is also discussed in order to further support the reviewed robotic and virtual reality thought-based control paradigms.

Virtual sensors for active noise control in acoustic-structural coupled enclosures using structural sensing: part II--Optimization of structural sensor placement.

PubMed

Halim, Dunant; Cheng, Li; Su, Zhongqing

2011-04-01

The work proposed an optimization approach for structural sensor placement to improve the performance of vibro-acoustic virtual sensor for active noise control applications. The vibro-acoustic virtual sensor was designed to estimate the interior sound pressure of an acoustic-structural coupled enclosure using structural sensors. A spectral-spatial performance metric was proposed, which was used to quantify the averaged structural sensor output energy of a vibro-acoustic system excited by a spatially varying point source. It was shown that (i) the overall virtual sensing error energy was contributed additively by the modal virtual sensing error and the measurement noise energy; (ii) each of the modal virtual sensing error system was contributed by both the modal observability levels for the structural sensing and the target acoustic virtual sensing; and further (iii) the strength of each modal observability level was influenced by the modal coupling and resonance frequencies of the associated uncoupled structural/cavity modes. An optimal design of structural sensor placement was proposed to achieve sufficiently high modal observability levels for certain important panel- and cavity-controlled modes. Numerical analysis on a panel-cavity system demonstrated the importance of structural sensor placement on virtual sensing and active noise control performance, particularly for cavity-controlled modes.

Robotic and Virtual Reality BCIs Using Spatial Tactile and Auditory Oddball Paradigms

PubMed Central

Rutkowski, Tomasz M.

2016-01-01

The paper reviews nine robotic and virtual reality (VR) brain–computer interface (BCI) projects developed by the author, in collaboration with his graduate students, within the BCI–lab research group during its association with University of Tsukuba, Japan. The nine novel approaches are discussed in applications to direct brain-robot and brain-virtual-reality-agent control interfaces using tactile and auditory BCI technologies. The BCI user intentions are decoded from the brainwaves in realtime using a non-invasive electroencephalography (EEG) and they are translated to a symbiotic robot or virtual reality agent thought-based only control. A communication protocol between the BCI output and the robot or the virtual environment is realized in a symbiotic communication scenario using an user datagram protocol (UDP), which constitutes an internet of things (IoT) control scenario. Results obtained from healthy users reproducing simple brain-robot and brain-virtual-agent control tasks in online experiments support the research goal of a possibility to interact with robotic devices and virtual reality agents using symbiotic thought-based BCI technologies. An offline BCI classification accuracy boosting method, using a previously proposed information geometry derived approach, is also discussed in order to further support the reviewed robotic and virtual reality thought-based control paradigms. PMID:27999538

Virtual Sensorimotor Training for Balance: Pilot Study Results for Children With Fetal Alcohol Spectrum Disorders.

PubMed

Jirikowic, Tracy; Westcott McCoy, Sarah; Price, Robert; Ciol, Marcia A; Hsu, Lin-Ya; Kartin, Deborah

2016-01-01

To examine the effects of Sensorimotor Training to Affect Balance, Engagement, and Learning (STABEL), a virtual reality system to train sensory adaptation for balance control, for children with fetal alcohol spectrum disorders (FASDs). Twenty-three children with FASDs received STABEL training in a university laboratory, or home, or were controls. The Movement Assessment Battery for Children-2nd edition (MABC-2) and Pediatric Clinical Test of Sensory Interaction for Balance-2 (P-CTSIB-2) were analyzed by group (lab, home, and control), session (pre-STABEL, 1 week post-STABEL, and 1 month post-STABEL), and group-by-session interaction. Significant effects were group and session for MABC-2 Balance and interaction for MABC-2 Total Motor and P-CTSIB-2. Preliminary results support improved sensory adaptation, balance, and motor performance post-STABEL, which warrant further study with a larger, randomized sample.

Towards photorealistic and immersive virtual-reality environments for simulated prosthetic vision: integrating recent breakthroughs in consumer hardware and software.

PubMed

Zapf, Marc P; Matteucci, Paul B; Lovell, Nigel H; Zheng, Steven; Suaning, Gregg J

2014-01-01

Simulated prosthetic vision (SPV) in normally sighted subjects is an established way of investigating the prospective efficacy of visual prosthesis designs in visually guided tasks such as mobility. To perform meaningful SPV mobility studies in computer-based environments, a credible representation of both the virtual scene to navigate and the experienced artificial vision has to be established. It is therefore prudent to make optimal use of existing hardware and software solutions when establishing a testing framework. The authors aimed at improving the realism and immersion of SPV by integrating state-of-the-art yet low-cost consumer technology. The feasibility of body motion tracking to control movement in photo-realistic virtual environments was evaluated in a pilot study. Five subjects were recruited and performed an obstacle avoidance and wayfinding task using either keyboard and mouse, gamepad or Kinect motion tracking. Walking speed and collisions were analyzed as basic measures for task performance. Kinect motion tracking resulted in lower performance as compared to classical input methods, yet results were more uniform across vision conditions. The chosen framework was successfully applied in a basic virtual task and is suited to realistically simulate real-world scenes under SPV in mobility research. Classical input peripherals remain a feasible and effective way of controlling the virtual movement. Motion tracking, despite its limitations and early state of implementation, is intuitive and can eliminate between-subject differences due to familiarity to established input methods.

Tools virtualization for command and control systems

NASA Astrophysics Data System (ADS)

Piszczek, Marek; Maciejewski, Marcin; Pomianek, Mateusz; Szustakowski, Mieczysław

2017-10-01

Information management is an inseparable part of the command process. The result is that the person making decisions at the command post interacts with data providing devices in various ways. Tools virtualization process can introduce a number of significant modifications in the design of solutions for management and command. The general idea involves replacing physical devices user interface with their digital representation (so-called Virtual instruments). A more advanced level of the systems "digitalization" is to use the mixed reality environments. In solutions using Augmented reality (AR) customized HMI is displayed to the operator when he approaches to each device. Identification of device is done by image recognition of photo codes. Visualization is achieved by (optical) see-through head mounted display (HMD). Control can be done for example by means of a handheld touch panel. Using the immersive virtual environment, the command center can be digitally reconstructed. Workstation requires only VR system (HMD) and access to information network. Operator can interact with devices in such a way as it would perform in real world (for example with the virtual hands). Because of their procedures (an analysis of central vision, eye tracking) MR systems offers another useful feature of reducing requirements for system data throughput. Due to the fact that at the moment we focus on the single device. Experiments carried out using Moverio BT-200 and SteamVR systems and the results of experimental application testing clearly indicate the ability to create a fully functional information system with the use of mixed reality technology.

Effects of virtual reality training on mobility in individuals with Parkinson's disease.

PubMed

Melo, G; Kleiner, A F R; Lopes, J; Zen, G Z D; Marson, N; Santos, T; Dumont, A; Galli, M; Oliveira, C

2018-06-19

The aim of the present study was to evaluate the effects of gait training with virtual reality (VR) on mobility in patients with Parkinson's disease (PD). Thirty-seven individuals with PD were allocated to three groups (control = 12, VR = 12 and treadmill = 13) submitted to 12 twenty-minute training sessions. Evaluations involved the Timed Up and Go (TUG) test before the intervention, after one session, after all 12 sessions and 30 days after the end of the intervention. The groups submitted to VR and treadmill training took less time to execute the TUG test than the control group. Individuals with PD submitted to VR and treadmill gait training presented mobility improvements in comparison to traditional physiotherapeutic training. Copyright © 2018. Published by Elsevier B.V.

Study on virtual instrument developing system based on intelligent virtual control

NASA Astrophysics Data System (ADS)

Tang, Baoping; Cheng, Fabin; Qin, Shuren

2005-01-01

The paper introduces a non-programming developing system of a virtual instument (VI), i.e., a virtual measurement instrument developing system (VMIDS) based on intelligent virtual control (IVC). The background of the IVC-based VMIDS is described briefly, and the hierarchical message bus (HMB)-based software architecture of VMIDS is discussed in detail. The three parts and functions of VMIDS are introduced, and the process of non-programming developing VI is further described.

Understanding Evolutionary Potential in Virtual CPU Instruction Set Architectures

PubMed Central

Bryson, David M.; Ofria, Charles

2013-01-01

We investigate fundamental decisions in the design of instruction set architectures for linear genetic programs that are used as both model systems in evolutionary biology and underlying solution representations in evolutionary computation. We subjected digital organisms with each tested architecture to seven different computational environments designed to present a range of evolutionary challenges. Our goal was to engineer a general purpose architecture that would be effective under a broad range of evolutionary conditions. We evaluated six different types of architectural features for the virtual CPUs: (1) genetic flexibility: we allowed digital organisms to more precisely modify the function of genetic instructions, (2) memory: we provided an increased number of registers in the virtual CPUs, (3) decoupled sensors and actuators: we separated input and output operations to enable greater control over data flow. We also tested a variety of methods to regulate expression: (4) explicit labels that allow programs to dynamically refer to specific genome positions, (5) position-relative search instructions, and (6) multiple new flow control instructions, including conditionals and jumps. Each of these features also adds complication to the instruction set and risks slowing evolution due to epistatic interactions. Two features (multiple argument specification and separated I/O) demonstrated substantial improvements in the majority of test environments, along with versions of each of the remaining architecture modifications that show significant improvements in multiple environments. However, some tested modifications were detrimental, though most exhibit no systematic effects on evolutionary potential, highlighting the robustness of digital evolution. Combined, these observations enhance our understanding of how instruction architecture impacts evolutionary potential, enabling the creation of architectures that support more rapid evolution of complex solutions to a broad range of challenges. PMID:24376669

A virtual reality task based on animal research – spatial learning and memory in patients after the first episode of schizophrenia

PubMed Central

Fajnerová, Iveta; Rodriguez, Mabel; Levčík, David; Konrádová, Lucie; Mikoláš, Pavol; Brom, Cyril; Stuchlík, Aleš; Vlček, Kamil; Horáček, Jiří

2014-01-01

Objectives: Cognitive deficit is considered to be a characteristic feature of schizophrenia disorder. A similar cognitive dysfunction was demonstrated in animal models of schizophrenia. However, the poor comparability of methods used to assess cognition in animals and humans could be responsible for low predictive validity of current animal models. In order to assess spatial abilities in schizophrenia and compare our results with the data obtained in animal models, we designed a virtual analog of the Morris water maze (MWM), the virtual Four Goals Navigation (vFGN) task. Methods: Twenty-nine patients after the first psychotic episode with schizophrenia symptoms and a matched group of healthy volunteers performed the vFGN task. They were required to find and remember four hidden goal positions in an enclosed virtual arena. The task consisted of two parts. The Reference memory (RM) session with a stable goal position was designed to test spatial learning. The Delayed-matching-to-place (DMP) session presented a modified working memory protocol designed to test the ability to remember a sequence of three hidden goal positions. Results: Data obtained in the RM session show impaired spatial learning in schizophrenia patients compared to the healthy controls in pointing and navigation accuracy. The DMP session showed impaired spatial memory in schizophrenia during the recall of spatial sequence and a similar deficit in spatial bias in the probe trials. The pointing accuracy and the quadrant preference showed higher sensitivity toward the cognitive deficit than the navigation accuracy. Direct navigation to the goal was affected by sex and age of the tested subjects. The age affected spatial performance only in healthy controls. Conclusions: Despite some limitations of the study, our results correspond well with the previous studies in animal models of schizophrenia and support the decline of spatial cognition in schizophrenia, indicating the usefulness of the vFGN task in comparative research. PMID:24904329

Water Quality Criteria for Hexahydro-1,3,5-Trinitro-1,3,5-Triazine (RDX)

DTIC Science & Technology

1986-06-01

Guidelines ( OECD 1981) for testing of chemicals require that mortality of controls should not exceed 20 percent at the end of the test, and that the average...of the accumulated RDX, but virtually no eliminatio, occurred from either muscle or viscera in bluegill sunfish (Bentley et alk . 1977). No maximum...Organisation for Economic Co-Operation and Development ( OECD ). 1981. OECD Guidelines for Testing of Chemicals. OECD Publications and Infor- mation Center

Interrater Reliability of the Power Mobility Road Test in the Virtual Reality-Based Simulator-2.

PubMed

Kamaraj, Deepan C; Dicianno, Brad E; Mahajan, Harshal P; Buhari, Alhaji M; Cooper, Rory A

2016-07-01

To assess interrater reliability of the Power Mobility Road Test (PMRT) when administered through the Virtual Reality-based SIMulator-version 2 (VRSIM-2). Within-subjects repeated-measures design. Participants interacted with VRSIM-2 through 2 display options (desktop monitor vs immersive virtual reality screens) using 2 control interfaces (roller system vs conventional movement-sensing joystick), providing 4 different driving scenarios (driving conditions 1-4). Participants performed 3 virtual driving sessions for each of the 2 display screens and 1 session through a real-world driving course (driving condition 5). The virtual PMRT was conducted in a simulated indoor office space, and an equivalent course was charted in an open space for the real-world assessment. After every change in driving condition, participants completed a self-reported workload assessment questionnaire, the Task Load Index, developed by the National Aeronautics and Space Administration. A convenience sample of electric-powered wheelchair (EPW) athletes (N=21) recruited at the 31st National Veterans Wheelchair Games. Not applicable. Total composite PMRT score. The PMRT had high interrater reliability (intraclass correlation coefficient [ICC]>.75) between the 2 raters in all 5 driving conditions. Post hoc analyses revealed that the reliability analyses had >80% power to detect high ICCs in driving conditions 1 and 4. The PMRT has high interrater reliability in conditions 1 and 4 and could be used to assess EPW driving performance virtually in VRSIM-2. However, further psychometric assessment is necessary to assess the feasibility of administering the PMRT using the different interfaces of VRSIM-2. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Testing the Data Assimilation Capability of the Profiler Virtual Module

DTIC Science & Technology

2016-02-01

ARL-TR-7601 ● FEB 2016 US Army Research Laboratory Testing the Data Assimilation Capability of the Profiler Virtual Module by...originator. ARL-TR-7601 ● FEB 2016 US Army Research Laboratory Testing the Data Assimilation Capability of the Profiler Virtual...hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and

Brief virtual reality therapy for public speaking anxiety.

PubMed

Harris, Sandra R; Kemmerling, Robert L; North, Max M

2002-12-01

The primary goal of this research program was to investigate the effectiveness of virtual reality therapy (VRT) in reducing public speaking anxiety of university students. The prevalence and impact of public speaking anxiety as a type of Social Phobia are discussed. Studies of VRT as an emerging treatment for psychological problems are reviewed. In the present study, eight students completed VRT individual treatment and post-testing, and six students in a Wait-List control group completed post-testing. Assessment measures included four self-report inventories, self-report of Subjective Units of Discomfort during exposure to VRT and physiological measurements of heart rate during speaking tasks. Four weekly individual exposure treatment sessions of approximately 15 min each were conducted by the author serving as therapist. Results on self-report and physiological measures appear to indicate that four virtual reality treatment sessions were effective in reducing public speaking anxiety in university students, corroborating earlier studies of VRT's effectiveness as a psychotherapeutic modality. Future research directions are discussed, primarily the need for research on younger populations, to assess the effectiveness of VRT for earlier intervention with public speaking anxiety.

Comparing Science Virtual and Paper-Based Test to Measure Students’ Critical Thinking based on VAK Learning Style Model

NASA Astrophysics Data System (ADS)

Rosyidah, T. H.; Firman, H.; Rusyati, L.

2017-02-01

This research was comparing virtual and paper-based test to measure students’ critical thinking based on VAK (Visual-Auditory-Kynesthetic) learning style model. Quasi experiment method with one group post-test only design is applied in this research in order to analyze the data. There was 40 eight grade students at one of public junior high school in Bandung becoming the sample in this research. The quantitative data was obtained through 26 questions about living thing and environment sustainability which is constructed based on the eight elements of critical thinking and be provided in the form of virtual and paper-based test. Based on analysis of the result, it is shown that within visual, auditory, and kinesthetic were not significantly difference in virtual and paper-based test. Besides, all result was supported by quistionnaire about students’ respond on virtual test which shows 3.47 in the scale of 4. Means that student showed positive respond in all aspet measured, which are interest, impression, and expectation.

Evaluation of the Use of a Virtual Patient on Student Competence and Confidence in Performing Simulated Clinic Visits.

PubMed

Taglieri, Catherine A; Crosby, Steven J; Zimmerman, Kristin; Schneider, Tulip; Patel, Dhiren K

2017-06-01

Objective. To assess the effect of incorporating virtual patient activities in a pharmacy skills lab on student competence and confidence when conducting real-time comprehensive clinic visits with mock patients. Methods. Students were randomly assigned to a control or intervention group. The control group completed the clinic visit prior to completing virtual patient activities. The intervention group completed the virtual patient activities prior to the clinic visit. Student proficiency was evaluated in the mock lab. All students completed additional exercises with the virtual patient and were subsequently assessed. Student impressions were assessed via a pre- and post-experience survey. Results. Student performance conducting clinic visits was higher in the intervention group compared to the control group. Overall student performance continued to improve in the subsequent module. There was no change in student confidence from pre- to post-experience. Student rating of the ease of use and realistic simulation of the virtual patient increased; however, student rating of the helpfulness of the virtual patient decreased. Despite student rating of the helpfulness of the virtual patient program, student performance improved. Conclusion. Virtual patient activities enhanced student performance during mock clinic visits. Students felt the virtual patient realistically simulated a real patient. Virtual patients may provide additional learning opportunities for students.

Virtual gaming simulation of a mental health assessment: A usability study.

PubMed

Verkuyl, Margaret; Romaniuk, Daria; Mastrilli, Paula

2018-05-18

Providing safe and realistic virtual simulations could be an effective way to facilitate the transition from the classroom to clinical practice. As nursing programs begin to include virtual simulations as a learning strategy; it is critical to first assess the technology for ease of use and usefulness. A virtual gaming simulation was developed, and a usability study was conducted to assess its ease of use and usefulness for students and faculty. The Technology Acceptance Model provided the framework for the study, which included expert review and testing by nursing faculty and nursing students. This study highlighted the importance of assessing ease of use and usefulness in a virtual game simulation and provided feedback for the development of an effective virtual gaming simulation. The study participants said the virtual gaming simulation was engaging, realistic and similar to a clinical experience. Participants found the game easy to use and useful. Testing provided the development team with ideas to improve the user interface. The usability methodology provided is a replicable approach to testing virtual experiences before a research study or before implementing virtual experiences into curriculum. Copyright © 2018 Elsevier Ltd. All rights reserved.

The influence of action on episodic memory: a virtual reality study.

PubMed

Plancher, Gaën; Barra, Julien; Orriols, Eric; Piolino, Pascale

2013-01-01

A range of empirical findings suggest that active learning is important for memory. However, few studies have focused on the mechanisms underlying this enactment effect in episodic memory using complex environments. Research using virtual reality has yielded inconsistent results. We postulated that the effect of action depends on the degree of interaction with the environment and freedom in the planning of an itinerary. To test these hypotheses, we disentangled the interaction and planning components of action to investigate whether each enhances factual and spatial memory. Seventy-two participants (36 male and 36 female) explored a virtual town in one of three experimental conditions: (a) a passive condition where participants were immersed as passenger of the car (no interaction, no planning); (b) a planning-only condition (the subject chose the itinerary but did not drive the car); (c) an interaction-only condition (the subject drove the car but the itinerary was fixed). We found that itinerary choice and motor control both enhanced spatial memory, while factual memory was impaired by online motor control. The role of action in memory is discussed.

Virtual Constraint Control of a Powered Prosthetic Leg: From Simulation to Experiments with Transfemoral Amputees.

PubMed

Gregg, Robert D; Lenzi, Tommaso; Hargrove, Levi J; Sensinger, Jonathon W

2014-12-01

Recent powered (or robotic) prosthetic legs independently control different joints and time periods of the gait cycle, resulting in control parameters and switching rules that can be difficult to tune by clinicians. This challenge might be addressed by a unifying control model used by recent bipedal robots, in which virtual constraints define joint patterns as functions of a monotonic variable that continuously represents the gait cycle phase. In the first application of virtual constraints to amputee locomotion, this paper derives exact and approximate control laws for a partial feedback linearization to enforce virtual constraints on a prosthetic leg. We then encode a human-inspired invariance property called effective shape into virtual constraints for the stance period. After simulating the robustness of the partial feedback linearization to clinically meaningful conditions, we experimentally implement this control strategy on a powered transfemoral leg. We report the results of three amputee subjects walking overground and at variable cadences on a treadmill, demonstrating the clinical viability of this novel control approach.

Virtual Constraint Control of a Powered Prosthetic Leg: From Simulation to Experiments with Transfemoral Amputees

PubMed Central

Lenzi, Tommaso; Hargrove, Levi J.; Sensinger, Jonathon W.

2014-01-01

Recent powered (or robotic) prosthetic legs independently control different joints and time periods of the gait cycle, resulting in control parameters and switching rules that can be difficult to tune by clinicians. This challenge might be addressed by a unifying control model used by recent bipedal robots, in which virtual constraints define joint patterns as functions of a monotonic variable that continuously represents the gait cycle phase. In the first application of virtual constraints to amputee locomotion, this paper derives exact and approximate control laws for a partial feedback linearization to enforce virtual constraints on a prosthetic leg. We then encode a human-inspired invariance property called effective shape into virtual constraints for the stance period. After simulating the robustness of the partial feedback linearization to clinically meaningful conditions, we experimentally implement this control strategy on a powered transfemoral leg. We report the results of three amputee subjects walking overground and at variable cadences on a treadmill, demonstrating the clinical viability of this novel control approach. PMID:25558185

The comparison between science virtual and paper based test in measuring grade 7 students’ critical thinking

NASA Astrophysics Data System (ADS)

Dhitareka, P. H.; Firman, H.; Rusyati, L.

2018-05-01

This research is comparing science virtual and paper-based test in measuring grade 7 students’ critical thinking based on Multiple Intelligences and gender. Quasi experimental method with within-subjects design is conducted in this research in order to obtain the data. The population of this research was all seventh grade students in ten classes of one public secondary school in Bandung. There were 71 students within two classes taken randomly became the sample in this research. The data are obtained through 28 questions with a topic of living things and environmental sustainability constructed based on eight critical thinking elements proposed by Inch then the questions provided in science virtual and paper-based test. The data was analysed by using paired-samples t test when the data are parametric and Wilcoxon signed ranks test when the data are non-parametric. In general comparison, the p-value of the comparison between science virtual and paper-based tests’ score is 0.506, indicated that there are no significance difference between science virtual and paper-based test based on the tests’ score. The results are furthermore supported by the students’ attitude result which is 3.15 from the scale from 1 to 4, indicated that they have positive attitudes towards Science Virtual Test.

Playing in or out of character: user role differences in the experience of interactive storytelling.

PubMed

Roth, Christian; Vermeulen, Ivar; Vorderer, Peter; Klimmt, Christoph; Pizzi, David; Lugrin, Jean-Luc; Cavazza, Marc

2012-11-01

Interactive storytelling (IS) is a promising new entertainment technology synthesizing preauthored narrative with dynamic user interaction. Existing IS prototypes employ different modes to involve users in a story, ranging from individual avatar control to comprehensive control over the virtual environment. The current experiment tested whether different player modes (exerting local vs. global influence) yield different user experiences (e.g., senses of immersion vs. control). A within-subject design involved 34 participants playing the cinematic IS drama "Emo Emma"( 1 ) both in the local (actor) and in global (ghost) mode. The latter mode allowed free movement in the virtual environment and hidden influence on characters, objects, and story development. As expected, control-related experiential qualities (effectance, autonomy, flow, and pride) were more intense for players in the global (ghost) mode. Immersion-related experiences did not differ over modes. Additionally, men preferred the sense of command facilitated by the ghost mode, whereas women preferred the sense of involvement facilitated by the actor mode.

The impact of the Virtual Ophthalmology Clinic on medical students' learning: a randomised controlled trial

PubMed Central

Succar, T; Zebington, G; Billson, F; Byth, K; Barrie, S; McCluskey, P; Grigg, J

2013-01-01

Aim The Virtual Ophthalmology Clinic (VOC) is an interactive web-based teaching module, with special emphasis on history taking and clinical reasoning skills. The purpose of this study was to determine the impact of VOC on medical students' learning. Methods A randomised controlled trial (RCT) was conducted with medical students from the University of Sydney (n=188) who were randomly assigned into either an experimental (n=93) or a control group (n=95). A pre- and post-test and student satisfaction questionnaire were administered. Twelve months later a follow-up test was conducted to determine the long-term retention rate of graduates. Results There was a statistically significant (P<0.001) within-subject improvement pre- to post rotation in the number of correctly answered questions for both the control and experimental groups (mean improvement for control 10%, 95% CI 1.3–2.6, and for experimental 17.5%, 95% CI 3.0–4.0). The improvement was significantly greater in the experimental group (mean difference in improvement between groups 7.5%, 95% CI 0.8–2.3, P<0.001). At 12 months follow-up testing, the experimental group scored on average 1.6 (8%) (95%CI 0.4 to 2.7, P=0.007) higher than the controls. Conclusion On the basis of a statistically significant improvement in academic performance and highly positive student feedback, the implementation of VOC may provide a means to address challenges to ophthalmic learning outcomes in an already crowded medical curriculum. PMID:23867718

Augmented effects of EMG biofeedback interfaced with virtual reality on neuromuscular control and movement coordination during reaching in children with cerebral palsy.

PubMed

Yoo, Ji Won; Lee, Dong Ryul; Cha, Young Joo; You, Sung Hyun

2017-01-01

The purpose of the present study was to compare therapeutic effects of an electromyography (EMG) biofeedback augmented by virtual reality (VR) and EMG biofeedback alone on the triceps and biceps (T:B) muscle activity imbalance and elbow joint movement coordination during a reaching motor taskOBJECTIVE: To compare therapeutic effects of an electromyography (EMG) biofeedback augmented by virtual reality (VR) and EMG biofeedback alone on the triceps and biceps muscle activity imbalance and elbow joint movement coordination during a reaching motor task in normal children and children with spastic cerebral palsy (CP). 18 children with spastic CP (2 females; mean±standard deviation = 9.5 ± 1.96 years) and 8 normal children (3 females; mean ± standard deviation = 9.75 ± 2.55 years) were recruited from a local community center. All children with CP first underwent one intensive session of EMG feedback (30 minutes), followed by one session of the EMG-VR feedback (30 minutes) after a 1-week washout period. Clinical tests included elbow extension range of motion (ROM), biceps muscle strength, and box and block test. EMG triceps and biceps (T:B) muscle activity imbalance and reaching movement acceleration coordination were concurrently determined by EMG and 3-axis accelerometer measurements respectively. Independent t-test and one-way repeated analysis of variance (ANOVA) were performed at p < 0.05. The one-way repeated ANOVA was revealed to be significantly effective in elbow extension ROM (p = 0.01), biceps muscle strength (p = 0.01), and box and block test (p = 0.03). The one-way repeated ANOVA also revealed to be significantly effective in the peak triceps muscle activity (p = 0.01). However, one-way repeated ANOVA produced no statistical significance in the composite 3-dimensional movement acceleration coordination data (p = 0.12). The present study is a first clinical trial that demonstrated the superior benefits of the EMG biofeedback when augmented by virtual reality exercise games in children with spastic CP. The augmented EMG and VR feedback produced better neuromuscular balance control in the elbow joint than the EMG biofeedback alone.

An exploratory fNIRS study with immersive virtual reality: a new method for technical implementation.

PubMed

Seraglia, Bruno; Gamberini, Luciano; Priftis, Konstantinos; Scatturin, Pietro; Martinelli, Massimiliano; Cutini, Simone

2011-01-01

For over two decades Virtual Reality (VR) has been used as a useful tool in several fields, from medical and psychological treatments, to industrial and military applications. Only in recent years researchers have begun to study the neural correlates that subtend VR experiences. Even if the functional Magnetic Resonance Imaging (fMRI) is the most common and used technique, it suffers several limitations and problems. Here we present a methodology that involves the use of a new and growing brain imaging technique, functional Near-infrared Spectroscopy (fNIRS), while participants experience immersive VR. In order to allow a proper fNIRS probe application, a custom-made VR helmet was created. To test the adapted helmet, a virtual version of the line bisection task was used. Participants could bisect the lines in a virtual peripersonal or extrapersonal space, through the manipulation of a Nintendo Wiimote ® controller in order for the participants to move a virtual laser pointer. Although no neural correlates of the dissociation between peripersonal and extrapersonal space were found, a significant hemodynamic activity with respect to the baseline was present in the right parietal and occipital areas. Both advantages and disadvantages of the presented methodology are discussed.

Towards control of dexterous hand manipulations using a silicon Pattern Generator.

PubMed

Russell, Alexander; Tenore, Francesco; Singhal, Girish; Thakor, Nitish; Etienne-Cummings, Ralph

2008-01-01

This work demonstrates how an in silico Pattern Generator (PG) can be used as a low power control system for rhythmic hand movements in an upper-limb prosthesis. Neural spike patterns, which encode rotation of a cylindrical object, were implemented in a custom Very Large Scale Integration chip. PG control was tested by using the decoded control signals to actuate the fingers of a virtual prosthetic arm. This system provides a framework for prototyping and controlling dexterous hand manipulation tasks in a compact and efficient solution.

Direct manipulation of virtual objects

NASA Astrophysics Data System (ADS)

Nguyen, Long K.

Interacting with a Virtual Environment (VE) generally requires the user to correctly perceive the relative position and orientation of virtual objects. For applications requiring interaction in personal space, the user may also need to accurately judge the position of the virtual object relative to that of a real object, for example, a virtual button and the user's real hand. This is difficult since VEs generally only provide a subset of the cues experienced in the real world. Complicating matters further, VEs presented by currently available visual displays may be inaccurate or distorted due to technological limitations. Fundamental physiological and psychological aspects of vision as they pertain to the task of object manipulation were thoroughly reviewed. Other sensory modalities -- proprioception, haptics, and audition -- and their cross-interactions with each other and with vision are briefly discussed. Visual display technologies, the primary component of any VE, were canvassed and compared. Current applications and research were gathered and categorized by different VE types and object interaction techniques. While object interaction research abounds in the literature, pockets of research gaps remain. Direct, dexterous, manual interaction with virtual objects in Mixed Reality (MR), where the real, seen hand accurately and effectively interacts with virtual objects, has not yet been fully quantified. An experimental test bed was designed to provide the highest accuracy attainable for salient visual cues in personal space. Optical alignment and user calibration were carefully performed. The test bed accommodated the full continuum of VE types and sensory modalities for comprehensive comparison studies. Experimental designs included two sets, each measuring depth perception and object interaction. The first set addressed the extreme end points of the Reality-Virtuality (R-V) continuum -- Immersive Virtual Environment (IVE) and Reality Environment (RE). This validated, linked, and extended several previous research findings, using one common test bed and participant pool. The results provided a proven method and solid reference points for further research. The second set of experiments leveraged the first to explore the full R-V spectrum and included additional, relevant sensory modalities. It consisted of two full-factorial experiments providing for rich data and key insights into the effect of each type of environment and each modality on accuracy and timeliness of virtual object interaction. The empirical results clearly showed that mean depth perception error in personal space was less than four millimeters whether the stimuli presented were real, virtual, or mixed. Likewise, mean error for the simple task of pushing a button was less than four millimeters whether the button was real or virtual. Mean task completion time was less than one second. Key to the high accuracy and quick task performance time observed was the correct presentation of the visual cues, including occlusion, stereoscopy, accommodation, and convergence. With performance results already near optimal level with accurate visual cues presented, adding proprioception, audio, and haptic cues did not significantly improve performance. Recommendations for future research include enhancement of the visual display and further experiments with more complex tasks and additional control variables.

Improving physical fitness of individuals with intellectual and developmental disability through a Virtual Reality Intervention Program.

PubMed

Lotan, Meir; Yalon-Chamovitz, Shira; Weiss, Patrice L Tamar

2009-01-01

Individuals with intellectual and developmental disabilities (IDD) are in need of effective physical fitness training programs. The aim was to test the effectiveness of a Virtual Reality (VR)-based exercise program in improving the physical fitness of adults with IDD. A research group (N=30; mean age=52.3+/-5.8 years; moderate IDD level) was matched for age, IDD level and functional abilities with a control group (N=30, mean age=54.3+/-5.4 years). A 5-6 week fitness program consisting of two 30 min sessions per week included game-like exercises provided by the Sony PlayStation II EyeToy VR system. Changes in physical fitness were monitored by the Energy Expenditure Index (EEI), the modified 12 min walk/run and the Total Heart Beat Index (THBI). Significant (p<0.05) improvements in physical fitness were demonstrated for the research group in comparison to the control group for the Modified Cooper test and the THBI but not for the EEI test. The EEI, Modified Cooper and THBI tests were found feasible to evaluate physical fitness levels and change of individuals with IDD under clinical conditions. VR technology intervention was suitable for adults with IDD and resulted in significant improvements in the physical fitness levels of the participants.

Virtual prototyping and testing of in-vehicle interfaces.

PubMed

Bullinger, Hans-Jörg; Dangelmaier, Manfred

2003-01-15

Electronic innovations that are slowly but surely changing the very nature of driving need to be tested before being introduced to the market. To meet this need a system for integrated virtual prototyping and testing has been developed. Functional virtual prototypes of various traffic systems, such as driver assistance, driver information, and multimedia systems can now be easily tested in a driving simulator by a rapid prototyping approach. The system has been applied in recent R&D projects.

Behavioral Monitoring of Sexual Offenders Against Children in Virtual Risk Situations: A Feasibility Study.

PubMed

Fromberger, Peter; Meyer, Sabrina; Jordan, Kirsten; Müller, Jürgen L

2018-01-01

The decision about unsupervised privileges for sexual offenders against children (SOC) is one of the most difficult decisions for practitioners in forensic high-security hospitals. Facing the possible consequences of the decision for the society, a valid and reliable risk management of SOCs is essential. Some risk management approaches provide frameworks for the construction of relevant future risk situations. Due to ethical reasons, it is not possible to evaluate the validity of constructed risk situations in reality. The aim of the study was to test if behavioral monitoring of SOCs in high-immersive virtual risk situations provides additional information for risk management. Six SOCs and seven non-offender controls (NOC) walked through three virtual risk situations, confronting the participant with a virtual child character. The participant had to choose between predefined answers representing approach or avoidance behavior. Frequency of chosen answers were analyzed in regards to knowledge of the participants about coping skills and coping skills focused during therapy. SOCs and NOCs behavior differed only in one risk scenario. Furthermore, SOCs showed in 89% of all cases a behavior not corresponding to their own belief about adequate behavior in comparable risk situations. In 62% of all cases, SOCs behaved not corresponding to coping skills they stated that therapists focused on during therapy. In 50% of all cases, SOCs behaved in correspondence to coping skills therapists stated that they focused on during therapy. Therapists predicted the behavior of SOCs in virtual risk situations incorrect in 25% of all cases. Thus, virtual risk scenarios provide the possibility for practitioners to monitor the behavior of SOCs and to test their decisions on unsupervised privileges without endangering the community. This may provide additional information for therapy progress. Further studies are necessary to evaluate the predictive and ecological validity of behavioral monitoring in virtual risk situations for real life situations.

Virtual fetal pig dissection as an agent of knowledge acquisition and attitudinal change in female high school biology students

NASA Astrophysics Data System (ADS)

Maloney, Rebecca Scudari

One way to determine if all students can learn through the use of computers is to introduce a lesson taught completely via computers and compare the results with those gained when the same lesson is taught in a traditional manner. This study attempted to determine if a virtual fetal pig dissection can be used as a viable alternative for an actual dissection for females enrolled in high school biology classes by comparing the knowledge acquisition and attitudinal change between the experimental (virtual dissection) and control (actual dissection) groups. Two hundred and twenty-four students enrolled in biology classes in a suburban all-girl parochial high school participated in this study. Female students in an all-girl high school were chosen because research shows differences in science competency and computer usage between the genders that may mask the performance of females on computer-based tasks in a science laboratory exercise. Students who completed the virtual dissection scored significantly higher on practical test and objective tests that were used to measure knowledge acquisition. Attitudinal change was measured by examining the students' attitudes toward dissections, computer usage in the classroom, and toward biology both before and after the dissections using pre and post surveys. Significant results in positive gain scores were found in the virtual dissection group's attitude toward dissections, and their negative gain score toward virtual dissections. Attitudinal changes toward computers and biology were not significant. A purposefully selected sample of the students were interviewed, in addition to gathering a sample of the students' daily dissection journals, as data highlighting their thoughts and feelings about their dissection experience. Further research is suggested to determine if a virtual laboratory experience can be a substitute for actual dissections, or may serve as an enhancement to an actual dissection.

Behavioral Monitoring of Sexual Offenders Against Children in Virtual Risk Situations: A Feasibility Study

PubMed Central

Fromberger, Peter; Meyer, Sabrina; Jordan, Kirsten; Müller, Jürgen L.

2018-01-01

The decision about unsupervised privileges for sexual offenders against children (SOC) is one of the most difficult decisions for practitioners in forensic high-security hospitals. Facing the possible consequences of the decision for the society, a valid and reliable risk management of SOCs is essential. Some risk management approaches provide frameworks for the construction of relevant future risk situations. Due to ethical reasons, it is not possible to evaluate the validity of constructed risk situations in reality. The aim of the study was to test if behavioral monitoring of SOCs in high-immersive virtual risk situations provides additional information for risk management. Six SOCs and seven non-offender controls (NOC) walked through three virtual risk situations, confronting the participant with a virtual child character. The participant had to choose between predefined answers representing approach or avoidance behavior. Frequency of chosen answers were analyzed in regards to knowledge of the participants about coping skills and coping skills focused during therapy. SOCs and NOCs behavior differed only in one risk scenario. Furthermore, SOCs showed in 89% of all cases a behavior not corresponding to their own belief about adequate behavior in comparable risk situations. In 62% of all cases, SOCs behaved not corresponding to coping skills they stated that therapists focused on during therapy. In 50% of all cases, SOCs behaved in correspondence to coping skills therapists stated that they focused on during therapy. Therapists predicted the behavior of SOCs in virtual risk situations incorrect in 25% of all cases. Thus, virtual risk scenarios provide the possibility for practitioners to monitor the behavior of SOCs and to test their decisions on unsupervised privileges without endangering the community. This may provide additional information for therapy progress. Further studies are necessary to evaluate the predictive and ecological validity of behavioral monitoring in virtual risk situations for real life situations. PMID:29559934

A virtual reality test identifies the visuospatial strengths of adolescents with dyslexia.

PubMed

Attree, Elizabeth A; Turner, Mark J; Cowell, Naina

2009-04-01

Research suggests that the deficits characterizing dyslexia may also be associated with superior visuospatial abilities. Other research suggests that superior visuospatial abilities of people with dyslexia may not have been so far identified because of the lack of appropriate tests of real-life spatial ability. A recent small-scale study found that visuospatial superiority was evident in men with dyslexia. This study assessed the visuospatial ability of adolescents with dyslexia in order to determine whether these adolescents performed better on a pseudo real-life visuospatial test than did their nondyslexic peers. Forty-two adolescents took part in the study. There was an equal numerical split between the experimental and control groups. The experimental group all had a diagnosis of dyslexia by an educational psychologist or specialist teacher. Visuospatial ability was assessed using the Recall of Designs and the Pattern Construction subtests from the British Ability Scales (2nd edition; BAS-11) together with a computer-generated virtual environment test. The assessments were administered in a counterbalanced order. Adolescents with dyslexia tended to perform less well than their nondyslexic peers on the BAS-11 tests; however, this difference was not statistically significant. For the computer-generated virtual environment test (pseudo real-life measure), statistically significant higher scores were achieved by the dyslexic group. These findings suggest that adolescents with dyslexia may exhibit superior visuospatial strengths on certain pseudo real-life tests of spatial ability. The usefulness of these findings is discussed in relation to possible implications for assessment and educational intervention programs for adolescents with dyslexia.

Learning Desert Geomorphology Virtually versus in the Field

ERIC Educational Resources Information Center

Stumpf, Richard J., II; Douglass, John; Dorn, Ronald I.

2008-01-01

Statistical analyses of pre-test and post-test results, as well as qualitative insight obtained by essays, compared introductory physical geography college students who learned desert geomorphology only virtually, in the field and both ways. With the exception of establishing geographic context, the virtual field trip was statistically…

Southeastern Virtual Institute for Health Equity and Wellness (SEVIEW) Phase II

DTIC Science & Technology

2015-09-01

level intervention has been tested using community focus groups , following the CBPR approach • A Community Oral Health Promoter (COHP) has been hired...questionnaire immediately prior to their primary care visit and receive a summary printout for their physician; (B) The control group will take the...interactive tablet-based questionnaire, will show more improvement in the above outcomes than participants in the control group after 12 months of

A four-dimensional virtual hand brain-machine interface using active dimension selection.

PubMed

Rouse, Adam G

2016-06-01

Brain-machine interfaces (BMI) traditionally rely on a fixed, linear transformation from neural signals to an output state-space. In this study, the assumption that a BMI must control a fixed, orthogonal basis set was challenged and a novel active dimension selection (ADS) decoder was explored. ADS utilizes a two stage decoder by using neural signals to both (i) select an active dimension being controlled and (ii) control the velocity along the selected dimension. ADS decoding was tested in a monkey using 16 single units from premotor and primary motor cortex to successfully control a virtual hand avatar to move to eight different postures. Following training with the ADS decoder to control 2, 3, and then 4 dimensions, each emulating a grasp shape of the hand, performance reached 93% correct with a bit rate of 2.4 bits s(-1) for eight targets. Selection of eight targets using ADS control was more efficient, as measured by bit rate, than either full four-dimensional control or computer assisted one-dimensional control. ADS decoding allows a user to quickly and efficiently select different hand postures. This novel decoding scheme represents a potential method to reduce the complexity of high-dimension BMI control of the hand.

Prosthetic Leg Control in the Nullspace of Human Interaction.

PubMed

Gregg, Robert D; Martin, Anne E

2016-07-01

Recent work has extended the control method of virtual constraints, originally developed for autonomous walking robots, to powered prosthetic legs for lower-limb amputees. Virtual constraints define desired joint patterns as functions of a mechanical phasing variable, which are typically enforced by torque control laws that linearize the output dynamics associated with the virtual constraints. However, the output dynamics of a powered prosthetic leg generally depend on the human interaction forces, which must be measured and canceled by the feedback linearizing control law. This feedback requires expensive multi-axis load cells, and actively canceling the interaction forces may minimize the human's influence over the prosthesis. To address these limitations, this paper proposes a method for projecting virtual constraints into the nullspace of the human interaction terms in the output dynamics. The projected virtual constraints naturally render the output dynamics invariant with respect to the human interaction forces, which instead enter into the internal dynamics of the partially linearized prosthetic system. This method is illustrated with simulations of a transfemoral amputee model walking with a powered knee-ankle prosthesis that is controlled via virtual constraints with and without the proposed projection.

Control of an ER haptic master in a virtual slave environment for minimally invasive surgery applications

NASA Astrophysics Data System (ADS)

Han, Young-Min; Choi, Seung-Bok

2008-12-01

This paper presents the control performance of an electrorheological (ER) fluid-based haptic master device connected to a virtual slave environment that can be used for minimally invasive surgery (MIS). An already developed haptic joint featuring controllable ER fluid and a spherical joint mechanism is adopted for the master system. Medical forceps and an angular position measuring device are devised and integrated with the joint to establish the MIS master system. In order to embody a human organ in virtual space, a volumetric deformable object is used. The virtual object is then mathematically formulated by a shape-retaining chain-linked (S-chain) model. After evaluating the reflection force, computation time and compatibility with real-time control, the haptic architecture for MIS is established by incorporating the virtual slave with the master device so that the reflection force for the object of the virtual slave and the desired position for the master operator are transferred to each other. In order to achieve the desired force trajectories, a sliding mode controller is formulated and then experimentally realized. Tracking control performances for various force trajectories are evaluated and presented in the time domain.

Psychological benefits of virtual reality for patients in rehabilitation therapy.

PubMed

Chen, Chih-Hung; Jeng, Ming-Chang; Fung, Chin-Ping; Doong, Ji-Liang; Chuang, Tien-Yow

2009-05-01

Whether virtual rehabilitation is beneficial has not been determined. To investigate the psychological benefits of virtual reality in rehabilitation. An experimental group underwent therapy with a virtual-reality-based exercise bike, and a control group underwent the therapy without virtual-reality equipment. Hospital laboratory. 30 patients suffering from spinal-cord injury. A designed rehabilitation therapy. Endurance, Borg's rating-of-perceived-exertion scale, the Activation-Deactivation Adjective Check List (AD-ACL), and the Simulator Sickness Questionnaire. The differences between the experimental and control groups were significant for AD-ACL calmness and tension. A virtual-reality-based rehabilitation program can ease patients' tension and induce calm.

Rapid stepping test towards virtual visual objects: Feasibility and convergent validity in older adults.

PubMed

Hutzler, Yeshayahu; Korsensky, Olga; Laufer, Yocheved

2017-01-01

Rapid voluntary stepping has been recognized as an important measure of balance control. The purpose of this study was to assess the feasibility and convergent validity of a Rapid Stepping Test protocol utilizing a virtual reality SeeMeTM system (VR-RST) in elderly ambulatory and independent individuals living in a community residential home. Associations between step execution times determined by the system and the Activities-specific Balance Confidence (ABC) Questionnaire, and clinical measures of balance performance in the MiniBESTest and Timed Up and Go (TUG) test, were established in 60 participants (mean age 88.2 ± 5.0 years). All participants completed the study. The correlations of the ABC questionnaire and the clinical tests with VR-RST forward and backward stepping were moderate (ρ rage 0.42-0.52), and weak to moderate with sideward stepping (ρ rage 0.32-0.52). Moderate to strong correlations were found across stepping directions (ρ rage 0.45-0.87). Findings support the test's feasibility and validity and confirm the utility of the VR-RST as an assessment tool in an elderly population.

Virtual reality measures in neuropsychological assessment: a meta-analytic review.

PubMed

Neguț, Alexandra; Matu, Silviu-Andrei; Sava, Florin Alin; David, Daniel

2016-02-01

Virtual reality-based assessment is a new paradigm for neuropsychological evaluation, that might provide an ecological assessment, compared to paper-and-pencil or computerized neuropsychological assessment. Previous research has focused on the use of virtual reality in neuropsychological assessment, but no meta-analysis focused on the sensitivity of virtual reality-based measures of cognitive processes in measuring cognitive processes in various populations. We found eighteen studies that compared the cognitive performance between clinical and healthy controls on virtual reality measures. Based on a random effects model, the results indicated a large effect size in favor of healthy controls (g = .95). For executive functions, memory and visuospatial analysis, subgroup analysis revealed moderate to large effect sizes, with superior performance in the case of healthy controls. Participants' mean age, type of clinical condition, type of exploration within virtual reality environments, and the presence of distractors were significant moderators. Our findings support the sensitivity of virtual reality-based measures in detecting cognitive impairment. They highlight the possibility of using virtual reality measures for neuropsychological assessment in research applications, as well as in clinical practice.

Dynamic Flight Maneuvering Using Virtual Control Surfaces Generated by Trapped Vorticity

DTIC Science & Technology

2010-12-01

of a modified Dragon Eye UAV. These tests illustrated the possibility of controlled flight using open-loop flow control actuators. Future research...2 -1 0 1 2 z ( cm ) 0 1 2 3 4 5 1 2 3 4 5 Time (s)  (d eg ) Figure II-1 Step command tracking in plung: ideal reference model response...experimental results. The experimental results were obtained with the ball screws locked in position so that the wing model was only allowed to pitch

Estimation of detection thresholds for redirected walking techniques.

PubMed

Steinicke, Frank; Bruder, Gerd; Jerald, Jason; Frenz, Harald; Lappe, Markus

2010-01-01

In immersive virtual environments (IVEs), users can control their virtual viewpoint by moving their tracked head and walking through the real world. Usually, movements in the real world are mapped one-to-one to virtual camera motions. With redirection techniques, the virtual camera is manipulated by applying gains to user motion so that the virtual world moves differently than the real world. Thus, users can walk through large-scale IVEs while physically remaining in a reasonably small workspace. In psychophysical experiments with a two-alternative forced-choice task, we have quantified how much humans can unknowingly be redirected on physical paths that are different from the visually perceived paths. We tested 12 subjects in three different experiments: (E1) discrimination between virtual and physical rotations, (E2) discrimination between virtual and physical straightforward movements, and (E3) discrimination of path curvature. In experiment E1, subjects performed rotations with different gains, and then had to choose whether the visually perceived rotation was smaller or greater than the physical rotation. In experiment E2, subjects chose whether the physical walk was shorter or longer than the visually perceived scaled travel distance. In experiment E3, subjects estimate the path curvature when walking a curved path in the real world while the visual display shows a straight path in the virtual world. Our results show that users can be turned physically about 49 percent more or 20 percent less than the perceived virtual rotation, distances can be downscaled by 14 percent and upscaled by 26 percent, and users can be redirected on a circular arc with a radius greater than 22 m while they believe that they are walking straight.

How and Why Affective and Reactive Virtual Agents Will Bring New Insights on Social Cognitive Disorders in Schizophrenia? An Illustration with a Virtual Card Game Paradigm

PubMed Central

Oker, Ali; Prigent, Elise; Courgeon, Matthieu; Eyharabide, Victoria; Urbach, Mathieu; Bazin, Nadine; Amorim, Michel-Ange; Passerieux, Christine; Martin, Jean-Claude; Brunet-Gouet, Eric

2015-01-01

In recent decades, many studies have shown that schizophrenia is associated with severe social cognitive impairments affecting key components, such as the recognition of emotions, theory of mind, attributional style, and metacognition. Most studies investigated each construct separately, precluding analysis of the interactive and immersive nature of real-life situation. Specialized batteries of tests are under investigation to assess social cognition, which is thought now as a link between neurocognitive disorders and impaired functioning. However, this link accounts for a limited part of the variance of real-life functioning. To fill this gap, advances in virtual reality and affective computing have made it possible to carry out experimental investigations of naturalistic social cognition, in controlled conditions, with good reproducibility. This approach is illustrated with the description of a new paradigm based on an original virtual card game in which subjects interpret emotional displays from a female virtual agent, and decipher her helping intentions. Independent variables concerning emotional expression in terms of valence and intensity were manipulated. We show how several useful dependant variables, ranging from classic experimental psychology data to metacognition or subjective experiences records, may be extracted from a single experiment. Methodological issues about the immersion into a simulated intersubjective situation are considered. The example of this new flexible experimental setting, with regards to the many constructs recognized in social neurosciences, constitutes a rationale for focusing on this potential intermediate link between standardized tests and real-life functioning, and also for using it as an innovative media for cognitive remediation. PMID:25870549

How and why affective and reactive virtual agents will bring new insights on social cognitive disorders in schizophrenia? An illustration with a virtual card game paradigm.

PubMed

Oker, Ali; Prigent, Elise; Courgeon, Matthieu; Eyharabide, Victoria; Urbach, Mathieu; Bazin, Nadine; Amorim, Michel-Ange; Passerieux, Christine; Martin, Jean-Claude; Brunet-Gouet, Eric

2015-01-01

In recent decades, many studies have shown that schizophrenia is associated with severe social cognitive impairments affecting key components, such as the recognition of emotions, theory of mind, attributional style, and metacognition. Most studies investigated each construct separately, precluding analysis of the interactive and immersive nature of real-life situation. Specialized batteries of tests are under investigation to assess social cognition, which is thought now as a link between neurocognitive disorders and impaired functioning. However, this link accounts for a limited part of the variance of real-life functioning. To fill this gap, advances in virtual reality and affective computing have made it possible to carry out experimental investigations of naturalistic social cognition, in controlled conditions, with good reproducibility. This approach is illustrated with the description of a new paradigm based on an original virtual card game in which subjects interpret emotional displays from a female virtual agent, and decipher her helping intentions. Independent variables concerning emotional expression in terms of valence and intensity were manipulated. We show how several useful dependant variables, ranging from classic experimental psychology data to metacognition or subjective experiences records, may be extracted from a single experiment. Methodological issues about the immersion into a simulated intersubjective situation are considered. The example of this new flexible experimental setting, with regards to the many constructs recognized in social neurosciences, constitutes a rationale for focusing on this potential intermediate link between standardized tests and real-life functioning, and also for using it as an innovative media for cognitive remediation.

Human-rated Safety Certification of a High Voltage Robonaut Lithium-ion Battery

NASA Technical Reports Server (NTRS)

Jeevarajan, Judith; Yayathi, S.; Johnson, M.; Waligora, T.; Verdeyen, W.

2013-01-01

NASA's rigorous certification process is being followed for the R2 high voltage battery program for use of R2 on International Space Station (ISS). Rigorous development testing at appropriate levels to credible off-nominal conditions and review of test data led to design improvements for safety at the virtual cell, cartridge and battery levels. Tests were carried out at all levels to confirm that both hardware and software controls work. Stringent flight acceptance testing of the flight battery will be completed before launch for mission use on ISS.

Abstract and proportional myoelectric control for multi-fingered hand prostheses.

PubMed

Pistohl, Tobias; Cipriani, Christian; Jackson, Andrew; Nazarpour, Kianoush

2013-12-01

Powered hand prostheses with many degrees of freedom are moving from research into the market for prosthetics. In order to make use of the prostheses' full functionality, it is essential to study efficient ways of high dimensional myoelectric control. Human subjects can rapidly learn to employ electromyographic (EMG) activity of several hand and arm muscles to control the position of a cursor on a computer screen, even if the muscle-cursor map contradicts directions in which the muscles would act naturally. But can a similar control scheme be translated into real-time operation of a dexterous robotic hand? We found that despite different degrees of freedom in the effector output, the learning process for controlling a robotic hand was surprisingly similar to that for a virtual two-dimensional cursor. Control signals were derived from the EMG in two different ways, with a linear and a Bayesian filter, to test how stable user intentions could be conveyed through them. Our analysis indicates that without visual feedback, control accuracy benefits from filters that reject high EMG amplitudes. In summary, we conclude that findings on myoelectric control principles, studied in abstract, virtual tasks can be transferred to real-life prosthetic applications.

A Study on Immersion and Presence of a Portable Hand Haptic System for Immersive Virtual Reality

PubMed Central

Kim, Mingyu; Jeon, Changyu; Kim, Jinmo

2017-01-01

This paper proposes a portable hand haptic system using Leap Motion as a haptic interface that can be used in various virtual reality (VR) applications. The proposed hand haptic system was designed as an Arduino-based sensor architecture to enable a variety of tactile senses at low cost, and is also equipped with a portable wristband. As a haptic system designed for tactile feedback, the proposed system first identifies the left and right hands and then sends tactile senses (vibration and heat) to each fingertip (thumb and index finger). It is incorporated into a wearable band-type system, making its use easy and convenient. Next, hand motion is accurately captured using the sensor of the hand tracking system and is used for virtual object control, thus achieving interaction that enhances immersion. A VR application was designed with the purpose of testing the immersion and presence aspects of the proposed system. Lastly, technical and statistical tests were carried out to assess whether the proposed haptic system can provide a new immersive presence to users. According to the results of the presence questionnaire and the simulator sickness questionnaire, we confirmed that the proposed hand haptic system, in comparison to the existing interaction that uses only the hand tracking system, provided greater presence and a more immersive environment in the virtual reality. PMID:28513545

Media Matter: The Effect of Medium of Presentation on Student's Recognition of Histopathology.

PubMed

Telang, Ajay; Jong, Nynke De; Dalen, Jan Van

2016-12-01

Pathology teaching has undergone transformation with the introduction of virtual microscopy as a teaching and learning tool. To assess if dental students can identify histopathology irrespective of the media of presentation and if the media affect student's oral pathology case based learning scores. The perception of students towards "hybrid" approach in teaching and learning histopathology in oral pathology was also assessed. A controlled experiment was conduc-ted on year 4 and year 5 dental student groups using a perfor-mance test and a questionnaire survey. A response rate of 81% was noted for the performance test as well as the questionnaire survey. Results show a significant effect of media on performance of students with virtual microscopy bringing out the best performance across all student groups in case based learning scenarios. The order of preference for media was found to be virtual microscopy followed by photomicrographs and light microscopy. However, 94% of students still prefer the present hybrid system for teaching and learning of oral pathology. The study shows that identification of histo-pathology by students is dependent on media and the type of media has a significant effect on the performance. Virtual microscopy is strongly perceived as a useful tool for learning which thus brings out the best performance, however; the hybrid approach still remains the most preferred approach for histopathology learning.

A Study on Immersion and Presence of a Portable Hand Haptic System for Immersive Virtual Reality.

PubMed

Kim, Mingyu; Jeon, Changyu; Kim, Jinmo

2017-05-17

This paper proposes a portable hand haptic system using Leap Motion as a haptic interface that can be used in various virtual reality (VR) applications. The proposed hand haptic system was designed as an Arduino-based sensor architecture to enable a variety of tactile senses at low cost, and is also equipped with a portable wristband. As a haptic system designed for tactile feedback, the proposed system first identifies the left and right hands and then sends tactile senses (vibration and heat) to each fingertip (thumb and index finger). It is incorporated into a wearable band-type system, making its use easy and convenient. Next, hand motion is accurately captured using the sensor of the hand tracking system and is used for virtual object control, thus achieving interaction that enhances immersion. A VR application was designed with the purpose of testing the immersion and presence aspects of the proposed system. Lastly, technical and statistical tests were carried out to assess whether the proposed haptic system can provide a new immersive presence to users. According to the results of the presence questionnaire and the simulator sickness questionnaire, we confirmed that the proposed hand haptic system, in comparison to the existing interaction that uses only the hand tracking system, provided greater presence and a more immersive environment in the virtual reality.

High-level virtual reality simulator for endourologic procedures of lower urinary tract.

PubMed

Reich, Oliver; Noll, Margarita; Gratzke, Christian; Bachmann, Alexander; Waidelich, Raphaela; Seitz, Michael; Schlenker, Boris; Baumgartner, Reinhold; Hofstetter, Alfons; Stief, Christian G

2006-06-01

To analyze the limitations of existing simulators for urologic techniques, and then test and evaluate a novel virtual reality (VR) simulator for endourologic procedures of the lower urinary tract. Surgical simulation using VR has the potential to have a tremendous impact on surgical training, testing, and certification. Endourologic procedures seem to be an ideal target for VR systems. The URO-Trainer features genuine VR, obtained from digital video footage of more than 400 endourologic diagnostic and therapeutic procedures, as well as data from cross-sectional imaging. The software offers infinite random variations of the anatomy and pathologic features for diagnosis and surgical intervention. An advanced haptic force feedback is incorporated. Virtual cystoscopy and resection of bladder tumors were evaluated by 24 medical students and 12 residents at our department. The system was assessed by more than 150 international urologists with varying experience at different conventions and workshops from March 2003 to September 2004. Because of these evaluations and constant evolutions, the final version provides a genuine representation of endourologic procedures. Objective data are generated by a tutoring system that has documented evident teaching benefits for medical students and residents in cystoscopy and treatment of bladder tumors. The URO-Trainer represents the latest generation of endoscopy simulators. Authentic visual and haptic sensations, unlimited virtual cases, and an intelligent tutoring system make this modular system an important improvement in computer-based training and quality control in urology.

Virtual Reality Intervention for Older Women with Breast Cancer

PubMed Central

SCHNEIDER, SUSAN M.; ELLIS, MATHEW; COOMBS, WILLIAM T.; SHONKWILER, ERIN L.; FOLSOM, LINDA C.

2013-01-01

This study examined the effects of a virtual reality distraction intervention on chemotherapy-related symptom distress levels in 16 women aged 50 and older. A cross-over design was used to answer the following research questions: (1) Is virtual reality an effective distraction intervention for reducing chemotherapy-related symptom distress levels in older women with breast cancer? (2) Does virtual reality have a lasting effect? Chemotherapy treatments are intensive and difficult to endure. One way to cope with chemotherapy-related symptom distress is through the use of distraction. For this study, a head-mounted display (Sony PC Glasstron PLM—S700) was used to display encompassing images and block competing stimuli during chemotherapy infusions. The Symptom Distress Scale (SDS), Revised Piper Fatigue Scale (PFS), and the State Anxiety Inventory (SAI) were used to measure symptom distress. For two matched chemotherapy treatments, one pre-test and two post-test measures were employed. Participants were randomly assigned to receive the VR distraction intervention during one chemotherapy treatment and received no distraction intervention (control condition) during an alternate chemotherapy treatment. Analysis using paired t-tests demonstrated a significant decrease in the SAI (p = 0.10) scores immediately following chemotherapy treatments when participants used VR. No significant changes were found in SDS or PFS values. There was a consistent trend toward improved symptoms on all measures 48 h following completion of chemotherapy. Evaluation of the intervention indicated that women thought the head mounted device was easy to use, they experienced no cybersickness, and 100% would use VR again. PMID:12855087

Fear reactivation prior to exposure therapy: does it facilitate the effects of VR exposure in a randomized clinical sample?

PubMed

Shiban, Youssef; Brütting, Johanna; Pauli, Paul; Mühlberger, Andreas

2015-03-01

The current study is the first to examine whether reactivation of fear memory prior to exposure therapy reduces relapse in a randomized clinical sample. In a standardized treatment protocol combining virtual reality and in-vivo exposure, patients underwent a fear reactivation procedure using a virtual spider 10 min prior to a virtual reality (VR) exposure (reactivation group: RG, n = 15). A control group (CG, n = 17) was exposed to a virtual plant 10 min prior to the VR exposure. Outcome measures were a VR spontaneous recovery test (SRT) and in-vivo a behavioral avoidance test assessed 24 h after VR exposure. One week later an in-vivo exposure session followed. Additionally, a follow-up using psychometric assessment was conducted six months after the first session. Both groups benefitted significantly and equally from the combined treatment, and importantly, the SRT revealed no return of fear in both groups. Furthermore, follow-up tests showed long-term treatment effects with no group differences. Due to different study components (VR treatment and in-vivo), we were not able to determine which treatment module was mainly responsible for the long-term treatment effect. Furthermore, no direct measure of memory destabilization was possible in this study. Our treatment package was highly effective in reducing phobic fear up to 6 months following treatment. Explicit fear reactivation prior to exposure was not beneficial in VR exposure treatment, possibly due to a failure to induce a memory destabilization or due to an implicit fear reactivation prior to treatment in both groups.

The effect of cognitive-motor dual task training with the biorescue force platform on cognition, balance and dual task performance in institutionalized older adults: a randomized controlled trial

PubMed Central

Delbroek, Tom; Vermeylen, Wietse; Spildooren, Joke

2017-01-01

[Purpose] This study investigates whether cognition, balance and dual task performance in institutionalized older adults improves by a virtual reality dual task training. [Subjects and Methods] Randomized controlled trial; Twenty institutionalized older adults with mild cognitive impairment (13 female, 7 male; average age, 87.2 ± 5.96 years) were randomized to the intervention (i.e. Virtual reality dual-task training using the BioRescue) or control group (no additional training). The intervention group took part in a 6-week training program while the elderly in the control group maintained their daily activities. Balance was measured with the Instrumented Timed Up-and-Go Test with and without a cognitive task. The Observed Emotion Rating Scale and Intrinsic Motivation Inventory were administered to evaluate the emotions and motivation regarding the exergaming program. [Results] The intervention group improved significantly on the total Timed Up-and-Go duration and the turn-to-sit duration during single-task walking in comparison to the control group who received no additional training. Participants found the virtual reality dual task training pleasant and useful for their concentration, memory and balance. Pleasure and alertness were the two emotions which were mostly seen during the intervention. [Conclusion] The BioRescue is a pleasant and interesting treatment method, well suited for institutionalized older adults in need of lifelong physical therapy. PMID:28744033

Asynchronous P300-based brain-computer interface to control a virtual environment: initial tests on end users.

PubMed

Aloise, Fabio; Schettini, Francesca; Aricò, Pietro; Salinari, Serenella; Guger, Christoph; Rinsma, Johanna; Aiello, Marco; Mattia, Donatella; Cincotti, Febo

2011-10-01

Motor disability and/or ageing can prevent individuals from fully enjoying home facilities, thus worsening their quality of life. Advances in the field of accessible user interfaces for domotic appliances can represent a valuable way to improve the independence of these persons. An asynchronous P300-based Brain-Computer Interface (BCI) system was recently validated with the participation of healthy young volunteers for environmental control. In this study, the asynchronous P300-based BCI for the interaction with a virtual home environment was tested with the participation of potential end-users (clients of a Frisian home care organization) with limited autonomy due to ageing and/or motor disabilities. System testing revealed that the minimum number of stimulation sequences needed to achieve correct classification had a higher intra-subject variability in potential end-users with respect to what was previously observed in young controls. Here we show that the asynchronous modality performed significantly better as compared to the synchronous mode in continuously adapting its speed to the users' state. Furthermore, the asynchronous system modality confirmed its reliability in avoiding misclassifications and false positives, as previously shown in young healthy subjects. The asynchronous modality may contribute to filling the usability gap between BCI systems and traditional input devices, representing an important step towards their use in the activities of daily living.

Virtual reality bronchoscopy simulation: a revolution in procedural training.

PubMed

Colt, H G; Crawford, S W; Galbraith, O

2001-10-01

In the airline industry, training is costly and operator error must be avoided. Therefore, virtual reality (VR) is routinely used to learn manual and technical skills through simulation before pilots assume flight responsibilities. In the field of medicine, manual and technical skills must also be acquired to competently perform invasive procedures such as flexible fiberoptic bronchoscopy (FFB). Until recently, training in FFB and other endoscopic procedures has occurred on the job in real patients. We hypothesized that novice trainees using a VR skill center could rapidly acquire basic skills, and that results would compare favorably with those of senior trainees trained in the conventional manner. We prospectively studied five novice bronchoscopists entering a pulmonary and critical care medicine training program. They were taught to perform inspection flexible bronchoscopy using a VR bronchoscopy skill center; dexterity, speed, and accuracy were tested using the skill center and an inanimate airway model before and after 4 h of group instruction and 4 h of individual unsupervised practice. Results were compared to those of a control group of four skilled physicians who had performed at least 200 bronchoscopies during 2 years of training. Student's t tests were used to compare mean scores of study and control groups for the inanimate model and VR bronchoscopy simulator. Before-training and after-training test scores were compared using paired t tests. For comparisons between after-training novice and skilled physician scores, unpaired two-sample t tests were used. Novices significantly improved their dexterity and accuracy in both models. They missed fewer segments after training than before training, and had fewer contacts with the bronchial wall. There was no statistically significant improvement in speed or total time spent not visualizing airway anatomy. After training, novice performance equaled or surpassed that of the skilled physicians. Novices performed more thorough examinations and missed significantly fewer segments in both the inanimate and virtual simulation models. A short, focused course of instruction and unsupervised practice using a virtual bronchoscopy simulator enabled novice trainees to attain a level of manual and technical skill at performing diagnostic bronchoscopic inspection similar to those of colleagues with several years of experience. These skills were readily reproducible in a conventional inanimate airway-training model, suggesting they would also be translatable to direct patient care.

Design and fabrication of complete dentures using CAD/CAM technology

PubMed Central

Han, Weili; Li, Yanfeng; Zhang, Yue; lv, Yuan; Zhang, Ying; Hu, Ping; Liu, Huanyue; Ma, Zheng; Shen, Yi

2017-01-01

Abstract The aim of the study was to test the feasibility of using commercially available computer-aided design and computer-aided manufacturing (CAD/CAM) technology including 3Shape Dental System 2013 trial version, WIELAND V2.0.049 and WIELAND ZENOTEC T1 milling machine to design and fabricate complete dentures. The modeling process of full denture available in the trial version of 3Shape Dental System 2013 was used to design virtual complete dentures on the basis of 3-dimensional (3D) digital edentulous models generated from the physical models. The virtual complete dentures designed were exported to CAM software of WIELAND V2.0.049. A WIELAND ZENOTEC T1 milling machine controlled by the CAM software was used to fabricate physical dentitions and baseplates by milling acrylic resin composite plates. The physical dentitions were bonded to the corresponding baseplates to form the maxillary and mandibular complete dentures. Virtual complete dentures were successfully designed using the software through several steps including generation of 3D digital edentulous models, model analysis, arrangement of artificial teeth, trimming relief area, and occlusal adjustment. Physical dentitions and baseplates were successfully fabricated according to the designed virtual complete dentures using milling machine controlled by a CAM software. Bonding physical dentitions to the corresponding baseplates generated the final physical complete dentures. Our study demonstrated that complete dentures could be successfully designed and fabricated by using CAD/CAM. PMID:28072686

Simulating Humans as Integral Parts of Spacecraft Missions

NASA Technical Reports Server (NTRS)

Bruins, Anthony C.; Rice, Robert; Nguyen, Lac; Nguyen, Heidi; Saito, Tim; Russell, Elaine

2006-01-01

The Collaborative-Virtual Environment Simulation Tool (C-VEST) software was developed for use in a NASA project entitled "3-D Interactive Digital Virtual Human." The project is oriented toward the use of a comprehensive suite of advanced software tools in computational simulations for the purposes of human-centered design of spacecraft missions and of the spacecraft, space suits, and other equipment to be used on the missions. The C-VEST software affords an unprecedented suite of capabilities for three-dimensional virtual-environment simulations with plug-in interfaces for physiological data, haptic interfaces, plug-and-play software, realtime control, and/or playback control. Mathematical models of the mechanics of the human body and of the aforementioned equipment are implemented in software and integrated to simulate forces exerted on and by astronauts as they work. The computational results can then support the iterative processes of design, building, and testing in applied systems engineering and integration. The results of the simulations provide guidance for devising measures to counteract effects of microgravity on the human body and for the rapid development of virtual (that is, simulated) prototypes of advanced space suits, cockpits, and robots to enhance the productivity, comfort, and safety of astronauts. The unique ability to implement human-in-the-loop immersion also makes the C-VEST software potentially valuable for use in commercial and academic settings beyond the original space-mission setting.

The Development of a Virtual Company to Support the Reengineering of the NASA/Goddard Hubble Space Telescope Control Center System

NASA Technical Reports Server (NTRS)

Lehtonen, Ken

1999-01-01

This is a report to the Third Annual International Virtual Company Conference, on The Development of a Virtual Company to Support the Reengineering of the NASA/Goddard Hubble Space Telescope (HST) Control Center System. It begins with a HST Science "Commercial": Brief Tour of Our Universe showing various pictures taken from the Hubble Space Telescope. The presentation then reviews the project background and goals. Evolution of the Control Center System ("CCS Inc.") is then reviewed. Topics of Interest to "virtual companies" are reviewed: (1) "How To Choose A Team" (2) "Organizational Model" (3) "The Human Component" (4) "'Virtual Trust' Among Teaming Companies" (5) "Unique Challenges to Working Horizontally" (6) "The Cultural Impact" (7) "Lessons Learned".

Discovering Novel Alternaria solani Succinate Dehydrogenase Inhibitors by In Silico Modeling and Virtual Screening Strategies to Combat Early Blight

NASA Astrophysics Data System (ADS)

Iftikhar, Sehrish; Shahid, Ahmad A.; Halim, Sobia A.; Wolters, Pieter J.; Vleeshouwers, Vivianne G. A. A.; Khan, Ajmal; Al-Harrasi, Ahmed; Ahmad, Shahbaz

2017-11-01

Alternaria blight is an important foliage disease caused by Alternaria solani. The enzyme Succinate dehydrogenase (SDH) is a potential drug target because of its role in tricarboxylic acid cycle. Hence targeting Alternaria solani SDH enzyme could be efficient tool to design novel fungicides against A. solani. We employed computational methodologies to design new SDH inhibitors using homology modeling; pharmacophore modeling and structure based virtual screening protocol. The three dimensional SDH model showed good stereo-chemical and structural properties. Based on virtual screening results twelve commercially available compounds were purchased and tested in vitro and in vivo. The compounds were found to inhibit mycelial growth of A. solani. Moreover in vitro trials showed that inhibitory effects were enhanced with increase in concentrations. Similarly increased disease control was observed in pre-treated potato tubers. Hence the applied in silico strategy led us to identify new and novel fungicides.

Discovering Novel Alternaria solani Succinate Dehydrogenase Inhibitors by in Silico Modeling and Virtual Screening Strategies to Combat Early Blight

PubMed Central

Iftikhar, Sehrish; Shahid, Ahmad A.; Halim, Sobia A.; Wolters, Pieter J.; Vleeshouwers, Vivianne G. A. A.; Khan, Ajmal; Al-Harrasi, Ahmed; Ahmad, Shahbaz

2017-01-01

Alternaria blight is an important foliage disease caused by Alternaria solani. The enzyme Succinate dehydrogenase (SDH) is a potential drug target because of its role in tricarboxylic acid cycle. Hence targeting Alternaria solani SDH enzyme could be efficient tool to design novel fungicides against A. solani. We employed computational methodologies to design new SDH inhibitors using homology modeling; pharmacophore modeling and structure based virtual screening. The three dimensional SDH model showed good stereo-chemical and structural properties. Based on virtual screening results twelve commercially available compounds were purchased and tested in vitro and in vivo. The compounds were found to inhibit mycelial growth of A. solani. Moreover in vitro trials showed that inhibitory effects were enhanced with increase in concentrations. Similarly increased disease control was observed in pre-treated potato tubers. Hence the applied in silico strategy led us to identify novel fungicides. PMID:29204422

Neglect assessment as an application of virtual reality.

PubMed

Broeren, J; Samuelsson, H; Stibrant-Sunnerhagen, K; Blomstrand, C; Rydmark, M

2007-09-01

In this study a cancellation task in a virtual environment was applied to describe the pattern of search and the kinematics of hand movements in eight patients with right hemisphere stroke. Four of these patients had visual neglect and four had recovered clinically from initial symptoms of neglect. The performance of the patients was compared with that of a control group consisting of eight subjects with no history of neurological deficits. Patients with neglect as well as patients clinically recovered from neglect showed aberrant search performance in the virtual reality (VR) task, such as mixed search pattern, repeated target pressures and deviating hand movements. The results indicate that in patients with a right hemispheric stroke, this VR application can provide an additional tool for assessment that can identify small variations otherwise not detectable with standard paper-and-pencil tests. VR technology seems to be well suited for the assessment of visually guided manual exploration in space.

Acquisition of Fire Safety Knowledge and Skills With Virtual Reality Simulation.

PubMed

Rossler, Kelly L; Sankaranarayanan, Ganesh; Duvall, Adrianne

2018-05-25

Prelicensure nursing students seeking to enter perioperative nursing need preparatory fire safety knowledge and skills training to participate as a member of an operating room (OR) team. This pilot study examined the effectiveness of the Virtual Electrosurgery Skill Trainer (VEST) on OR fire safety skills among prelicensure nursing students. An experimental pretest-posttest design was used in this study. Twenty nursing students were randomized to a control or an intervention group. Knowledge and skills acquisition of OR fire safety were assessed. There were no statistically significant findings in knowledge for either group. Fisher exact test demonstrated significant relationships between the skills performance criteria of following emergency procedures for a fire and demonstrating PASS (pull-aim-squeeze-sweep) technique (P = .001). Academic and hospital educators may consider incorporating virtual reality simulation to teach fire safety education or reinforce general fire safety practices to nursing students and novice nurses.

Immersive Virtual Reality Therapy with Myoelectric Control for Treatment-resistant Phantom Limb Pain: Case Report.

PubMed

Chau, Brian; Phelan, Ivan; Ta, Phillip; Humbert, Sarah; Hata, Justin; Tran, Duc

2017-01-01

Objective: Phantom limb pain is a condition frequently experienced after amputation. One treatment for phantom limb pain is traditional mirror therapy, yet some patients do not respond to this intervention, and immersive virtual reality mirror therapy offers some potential advantages. We report the case of a patient with severe phantom limb pain following an upper limb amputation and successful treatment with therapy in a custom virtual reality environment. Methods: An interactive 3-D kitchen environment was developed based on the principles of mirror therapy to allow for control of virtual hands while wearing a motion-tracked, head-mounted virtual reality display. The patient used myoelectric control of a virtual hand as well as motion-tracking control in this setting for five therapy sessions. Pain scale measurements and subjective feedback was elicited at each session. Results: Analysis of the measured pain scales showed statistically significant decreases per session [Visual Analog Scale, Short Form McGill Pain Questionnaire, and Wong-Baker FACES pain scores decreased by 55 percent (p=0.0143), 60 percent (p=0.023), and 90 percent (p=0.0024), respectively]. Significant subjective pain relief persisting between sessions was also reported, as well as marked immersion within the virtual environments. On followup at six weeks, the patient noted continued decrease in phantom limb pain symptoms. Conclusions: Currently available immersive virtual reality technology with myolectric and motion tracking control may represent a possible therapy option for treatment-resistant phantom limb pain.

Immersive Virtual Reality Therapy with Myoelectric Control for Treatment-resistant Phantom Limb Pain: Case Report

PubMed Central

Phelan, Ivan; Ta, Phillip; Humbert, Sarah; Hata, Justin; Tran, Duc

2017-01-01

Objective: Phantom limb pain is a condition frequently experienced after amputation. One treatment for phantom limb pain is traditional mirror therapy, yet some patients do not respond to this intervention, and immersive virtual reality mirror therapy offers some potential advantages. We report the case of a patient with severe phantom limb pain following an upper limb amputation and successful treatment with therapy in a custom virtual reality environment. Methods: An interactive 3-D kitchen environment was developed based on the principles of mirror therapy to allow for control of virtual hands while wearing a motion-tracked, head-mounted virtual reality display. The patient used myoelectric control of a virtual hand as well as motion-tracking control in this setting for five therapy sessions. Pain scale measurements and subjective feedback was elicited at each session. Results: Analysis of the measured pain scales showed statistically significant decreases per session [Visual Analog Scale, Short Form McGill Pain Questionnaire, and Wong-Baker FACES pain scores decreased by 55 percent (p=0.0143), 60 percent (p=0.023), and 90 percent (p=0.0024), respectively]. Significant subjective pain relief persisting between sessions was also reported, as well as marked immersion within the virtual environments. On followup at six weeks, the patient noted continued decrease in phantom limb pain symptoms. Conclusions: Currently available immersive virtual reality technology with myolectric and motion tracking control may represent a possible therapy option for treatment-resistant phantom limb pain. PMID:29616149

Ecological validity of virtual reality daily living activities screening for early dementia: longitudinal study.

PubMed

Tarnanas, Ioannis; Schlee, Winfried; Tsolaki, Magda; Müri, René; Mosimann, Urs; Nef, Tobias

2013-08-06

Dementia is a multifaceted disorder that impairs cognitive functions, such as memory, language, and executive functions necessary to plan, organize, and prioritize tasks required for goal-directed behaviors. In most cases, individuals with dementia experience difficulties interacting with physical and social environments. The purpose of this study was to establish ecological validity and initial construct validity of a fire evacuation Virtual Reality Day-Out Task (VR-DOT) environment based on performance profiles as a screening tool for early dementia. The objectives were (1) to examine the relationships among the performances of 3 groups of participants in the VR-DOT and traditional neuropsychological tests employed to assess executive functions, and (2) to compare the performance of participants with mild Alzheimer's-type dementia (AD) to those with amnestic single-domain mild cognitive impairment (MCI) and healthy controls in the VR-DOT and traditional neuropsychological tests used to assess executive functions. We hypothesized that the 2 cognitively impaired groups would have distinct performance profiles and show significantly impaired independent functioning in ADL compared to the healthy controls. The study population included 3 groups: 72 healthy control elderly participants, 65 amnestic MCI participants, and 68 mild AD participants. A natural user interface framework based on a fire evacuation VR-DOT environment was used for assessing physical and cognitive abilities of seniors over 3 years. VR-DOT focuses on the subtle errors and patterns in performing everyday activities and has the advantage of not depending on a subjective rating of an individual person. We further assessed functional capacity by both neuropsychological tests (including measures of attention, memory, working memory, executive functions, language, and depression). We also evaluated performance in finger tapping, grip strength, stride length, gait speed, and chair stands separately and while performing VR-DOTs in order to correlate performance in these measures with VR-DOTs because performance while navigating a virtual environment is a valid and reliable indicator of cognitive decline in elderly persons. The mild AD group was more impaired than the amnestic MCI group, and both were more impaired than healthy controls. The novel VR-DOT functional index correlated strongly with standard cognitive and functional measurements, such as mini-mental state examination (MMSE; rho=0.26, P=.01) and Bristol Activities of Daily Living (ADL) scale scores (rho=0.32, P=.001). Functional impairment is a defining characteristic of predementia and is partly dependent on the degree of cognitive impairment. The novel virtual reality measures of functional ability seem more sensitive to functional impairment than qualitative measures in predementia, thus accurately differentiating from healthy controls. We conclude that VR-DOT is an effective tool for discriminating predementia and mild AD from controls by detecting differences in terms of errors, omissions, and perseverations while measuring ADL functional ability.

Submillisecond Optical Knife-Edge Testing

NASA Technical Reports Server (NTRS)

Thurlow, P.

1983-01-01

Fast computer-controlled sampling of optical knife-edge response (KER) signal increases accuracy of optical system aberration measurement. Submicrosecond-response detectors in optical focal plane convert optical signals to electrical signals converted to digital data, sampled and feed into computer for storage and subsequent analysis. Optical data are virtually free of effects of index-of-refraction gradients.

Cognitive evaluation for the diagnosis of Alzheimer's disease based on Turing Test and Virtual Environments.

PubMed

Fernandez Montenegro, Juan Manuel; Argyriou, Vasileios

2017-05-01

Alzheimer's screening tests are commonly used by doctors to diagnose the patient's condition and stage as early as possible. Most of these tests are based on pen-paper interaction and do not embrace the advantages provided by new technologies. This paper proposes novel Alzheimer's screening tests based on virtual environments and game principles using new immersive technologies combined with advanced Human Computer Interaction (HCI) systems. These new tests are focused on the immersion of the patient in a virtual room, in order to mislead and deceive the patient's mind. In addition, we propose two novel variations of Turing Test proposed by Alan Turing as a method to detect dementia. As a result, four tests are introduced demonstrating the wide range of screening mechanisms that could be designed using virtual environments and game concepts. The proposed tests are focused on the evaluation of memory loss related to common objects, recent conversations and events; the diagnosis of problems in expressing and understanding language; the ability to recognize abnormalities; and to differentiate between virtual worlds and reality, or humans and machines. The proposed screening tests were evaluated and tested using both patients and healthy adults in a comparative study with state-of-the-art Alzheimer's screening tests. The results show the capacity of the new tests to distinguish healthy people from Alzheimer's patients. Copyright © 2017. Published by Elsevier Inc.

Laparoscopic virtual reality and box trainers: is one superior to the other?

PubMed

Munz, Y; Kumar, B D; Moorthy, K; Bann, S; Darzi, A

2004-03-01

Virtual reality (VR) simulators now have the potential to replace traditional methods of laparoscopic training. The aim of this study was to compare the VR simulator with the classical box trainer and determine whether one has advantages over the other. Twenty four novices were tested to determine their baseline laparoscopic skills and then randomized into the following three group: LapSim, box trainer, and no training (control). After 3 weekly training sessions lasting 30-min each, all subjects were reassessed. Assessment included motion analysis and error scores. Nonparametric tests were applied, and p < 0.05 was deemed significant. Both trained groups made significant improvements in all parameters measured ( p < 0.05). Compared to the controls, the box trainer group performed significantly better on most of the parameters, whereas the LapSim group performed significantly better on some parameters. There were no significant differences between the LapSim and box trainer groups. LapSim is effective in teaching skills that are transferable to a real laparoscopic task. However, there appear to be no substantial advantages of one system over the other.

Sweaty Palms! Virtual Reality Applied to Training.

ERIC Educational Resources Information Center

Treiber, Karin

A qualitative case study approach was used to identify the psychosocial effects of the high-fidelity, virtual reality simulation provided in the college-level air traffic control (ATC) training program offered at the Minnesota Air Traffic Control Training Center and to evaluate the applicability of virtual reality to academic/training situations.…

Analysis, design, and testing of a low cost, direct force command linear proof mass actuator for structural control

NASA Technical Reports Server (NTRS)

Slater, G. L.; Shelley, Stuart; Jacobson, Mark

1993-01-01

In this paper, the design, analysis, and test of a low cost, linear proof mass actuator for vibration control is presented. The actuator is based on a linear induction coil from a large computer disk drive. Such disk drives are readily available and provide the linear actuator, current feedback amplifier, and power supply for a highly effective, yet inexpensive, experimental laboratory actuator. The device is implemented as a force command input system, and the performance is virtually the same as other, more sophisticated, linear proof mass systems.

Environmental Social Stress, Paranoia and Psychosis Liability: A Virtual Reality Study

PubMed Central

Veling, Wim; Pot-Kolder, Roos; Counotte, Jacqueline; van Os, Jim; van der Gaag, Mark

2016-01-01

The impact of social environments on mental states is difficult to assess, limiting the understanding of which aspects of the social environment contribute to the onset of psychotic symptoms and how individual characteristics moderate this outcome. This study aimed to test sensitivity to environmental social stress as a mechanism of psychosis using Virtual Reality (VR) experiments. Fifty-five patients with recent onset psychotic disorder, 20 patients at ultra high risk for psychosis, 42 siblings of patients with psychosis, and 53 controls walked 5 times in a virtual bar with different levels of environmental social stress. Virtual social stressors were population density, ethnic density and hostility. Paranoia about virtual humans and subjective distress in response to virtual social stress exposures were measured with State Social Paranoia Scale (SSPS) and self-rated momentary subjective distress (SUD), respectively. Pre-existing (subclinical) symptoms were assessed with the Community Assessment of Psychic Experiences (CAPE), Green Paranoid Thoughts Scale (GPTS) and the Social Interaction Anxiety Scale (SIAS). Paranoia and subjective distress increased with degree of social stress in the environment. Psychosis liability and pre-existing symptoms, in particular negative affect, positively impacted the level of paranoia and distress in response to social stress. These results provide experimental evidence that heightened sensitivity to environmental social stress may play an important role in the onset and course of psychosis. PMID:27038469

Using a visual discrimination model for the detection of compression artifacts in virtual pathology images.

PubMed

Johnson, Jeffrey P; Krupinski, Elizabeth A; Yan, Michelle; Roehrig, Hans; Graham, Anna R; Weinstein, Ronald S

2011-02-01

A major issue in telepathology is the extremely large and growing size of digitized "virtual" slides, which can require several gigabytes of storage and cause significant delays in data transmission for remote image interpretation and interactive visualization by pathologists. Compression can reduce this massive amount of virtual slide data, but reversible (lossless) methods limit data reduction to less than 50%, while lossy compression can degrade image quality and diagnostic accuracy. "Visually lossless" compression offers the potential for using higher compression levels without noticeable artifacts, but requires a rate-control strategy that adapts to image content and loss visibility. We investigated the utility of a visual discrimination model (VDM) and other distortion metrics for predicting JPEG 2000 bit rates corresponding to visually lossless compression of virtual slides for breast biopsy specimens. Threshold bit rates were determined experimentally with human observers for a variety of tissue regions cropped from virtual slides. For test images compressed to their visually lossless thresholds, just-noticeable difference (JND) metrics computed by the VDM were nearly constant at the 95th percentile level or higher, and were significantly less variable than peak signal-to-noise ratio (PSNR) and structural similarity (SSIM) metrics. Our results suggest that VDM metrics could be used to guide the compression of virtual slides to achieve visually lossless compression while providing 5-12 times the data reduction of reversible methods.

Studying and Treating Schizophrenia Using Virtual Reality: A New Paradigm

PubMed Central

Freeman, Daniel

2008-01-01

Understanding schizophrenia requires consideration of patients’ interactions in the social world. Misinterpretation of other peoples’ behavior is a key feature of persecutory ideation. The occurrence and intensity of hallucinations is affected by the social context. Negative symptoms such as anhedonia, asociality, and blunted affect reflect difficulties in social interactions. Withdrawal and avoidance of other people is frequent in schizophrenia, leading to isolation and rumination. The use of virtual reality (VR)—interactive immersive computer environments—allows one of the key variables in understanding psychosis, social environments, to be controlled, providing exciting applications to research and treatment. Seven applications of virtual social environments to schizophrenia are set out: symptom assessment, identification of symptom markers, establishment of predictive factors, tests of putative causal factors, investigation of the differential prediction of symptoms, determination of toxic elements in the environment, and development of treatment. The initial VR studies of persecutory ideation, which illustrate the ascription of personalities and mental states to virtual people, are highlighted. VR, suitably applied, holds great promise in furthering the understanding and treatment of psychosis. PMID:18375568

Haptic, Virtual Interaction and Motor Imagery: Entertainment Tools and Psychophysiological Testing

PubMed Central

Invitto, Sara; Faggiano, Chiara; Sammarco, Silvia; De Luca, Valerio; De Paolis, Lucio T.

2016-01-01

In this work, the perception of affordances was analysed in terms of cognitive neuroscience during an interactive experience in a virtual reality environment. In particular, we chose a virtual reality scenario based on the Leap Motion controller: this sensor device captures the movements of the user’s hand and fingers, which are reproduced on a computer screen by the proper software applications. For our experiment, we employed a sample of 10 subjects matched by age and sex and chosen among university students. The subjects took part in motor imagery training and immersive affordance condition (a virtual training with Leap Motion and a haptic training with real objects). After each training sessions the subject performed a recognition task, in order to investigate event-related potential (ERP) components. The results revealed significant differences in the attentional components during the Leap Motion training. During Leap Motion session, latencies increased in the occipital lobes, which are entrusted to visual sensory; in contrast, latencies decreased in the frontal lobe, where the brain is mainly activated for attention and action planning. PMID:26999151

Haptic, Virtual Interaction and Motor Imagery: Entertainment Tools and Psychophysiological Testing.

PubMed

Invitto, Sara; Faggiano, Chiara; Sammarco, Silvia; De Luca, Valerio; De Paolis, Lucio T

2016-03-18

In this work, the perception of affordances was analysed in terms of cognitive neuroscience during an interactive experience in a virtual reality environment. In particular, we chose a virtual reality scenario based on the Leap Motion controller: this sensor device captures the movements of the user's hand and fingers, which are reproduced on a computer screen by the proper software applications. For our experiment, we employed a sample of 10 subjects matched by age and sex and chosen among university students. The subjects took part in motor imagery training and immersive affordance condition (a virtual training with Leap Motion and a haptic training with real objects). After each training sessions the subject performed a recognition task, in order to investigate event-related potential (ERP) components. The results revealed significant differences in the attentional components during the Leap Motion training. During Leap Motion session, latencies increased in the occipital lobes, which are entrusted to visual sensory; in contrast, latencies decreased in the frontal lobe, where the brain is mainly activated for attention and action planning.

Proof-of-principle demonstration of a virtual flow meter-based transducer for gaseous helium monitoring in particle accelerator cryogenics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Arpaia, P.; Technology Department, European Organization for Nuclear Research; Blanco, E.

2015-07-15

A transducer based on a virtual flow meter is proposed for monitoring helium distribution and consumption in cryogenic systems for particle accelerators. The virtual flow meter allows technical and economical constraints, preventing installation of physical instruments in all the needed measurement points, to be overcome. Virtual flow meter performance for the alternative models of Samson [ http://www.samson.de (2015)] and Sereg-Schlumberger [ http://www.slb.com/ (2015)] is compared with the standard IEC 60534-2-1 [Industrial-process control valves—Part 2-1: Flow capacity—sizing equations for fluid flow under installed conditions (2011), https://webstore.iec.ch/publication/2461], for a large temperature range, for both gaseous and liquid helium phases, and for differentmore » pressure drops. Then, the calibration function of the transducer is derived. Finally, the experimental validation for the helium gaseous state on the test station for superconducting magnets in the laboratory SM18 [Pirotte et al., AIP Conf. Proc. 1573, 187 (2014)] at CERN is reported.« less

Implementation of a virtual laboratory for training on sound insulation testing and uncertainty calculations in acoustic tests.

PubMed

Asensio, C; Gasco, L; Ruiz, M; Recuero, M

2015-02-01

This paper describes a methodology and case study for the implementation of educational virtual laboratories for practice training on acoustic tests according to international standards. The objectives of this activity are (a) to help the students understand and apply the procedures described in the standards and (b) to familiarize the students with the uncertainty in measurement and its estimation in acoustics. The virtual laboratory will not focus on the handling and set-up of real acoustic equipment but rather on procedures and uncertainty. The case study focuses on the application of the virtual laboratory for facade sound insulation tests according to ISO 140-5:1998 (International Organization for Standardization, Geneva, Switzerland, 1998), and the paper describes the causal and stochastic models and the constraints applied in the virtual environment under consideration. With a simple user interface, the laboratory will provide measurement data that the students will have to process to report the insulation results that must converge with the "virtual true values" in the laboratory. The main advantage of the virtual laboratory is derived from the customization of factors in which the student will be instructed or examined (for instance, background noise correction, the detection of sporadic corrupted observations, and the effect of instrument precision).

Interservice/Industry Training, Simulation and Education Conference Partnerships for Learning in the New Millennium Abstracts

DTIC Science & Technology

2000-01-01

for flight test data, and both generic and specialized tools of data filtering , data calibration, modeling , system identification, and simulation...GRAMMATICAL MODEL AND PARSER FOR AIR TRAFFIC CONTROLLER’S COMMANDS 11 A SPEECH-CONTROLLED INTERACTIVE VIRTUAL ENVIRONMENT FOR SHIP FAMILIARIZATION 12... MODELING AND SIMULATION IN THE 21ST CENTURY 23 NEW COTS HARDWARE AND SOFTWARE REDUCE THE COST AND EFFORT IN REPLACING AGING FLIGHT SIMULATORS SUBSYSTEMS

Immersive virtual reality-based training improves response in a simulated operating room fire scenario.

PubMed

Sankaranarayanan, Ganesh; Wooley, Lizzy; Hogg, Deborah; Dorozhkin, Denis; Olasky, Jaisa; Chauhan, Sanket; Fleshman, James W; De, Suvranu; Scott, Daniel; Jones, Daniel B

2018-01-25

SAGES FUSE curriculum provides didactic knowledge on OR fire prevention. The objective of this study is to evaluate the impact of an immersive virtual reality (VR)-based OR fire training simulation system in combination with FUSE didactics. The study compared a control with a simulation group. After a pre-test questionnaire that assessed the baseline knowledge, both groups were given didactic material that consists of a 10-min presentation and reading materials about precautions and stopping an OR fire from the FUSE manual. The simulation group practiced on the OR fire simulation for one session that consisted of five trials within a week from the pre-test. One week later, both groups were reassessed using a questionnaire. A week after the post-test both groups also participated in a simulated OR fire scenario while their performance was videotaped for assessment. A total of 20 subjects (ten per group) participated in this IRB approved study. Median test scores for the control group increased from 5.5 to 9.00 (p = 0.011) and for the simulation group it increased from 5.0 to 8.5 (p = 0.005). Both groups started at the same baseline (pre-test, p = 0.529) and reached similar level in cognitive knowledge (post-test, p = 0.853). However, when tested in the mock OR fire scenario, 70% of the simulation group subjects were able to perform the correct sequence of steps in extinguishing the simulated fire whereas only 20% subjects in the control group were able to do so (p = 0.003). The simulation group was better than control group in correctly identifying the oxidizer (p = 0.03) and ignition source (p = 0.014). Interactive VR-based hands-on training was found to be a relatively inexpensive and effective mode for teaching OR fire prevention and management scenarios.

Virtual reality does not meet expectations in a pilot study on multimodal laparoscopic surgery training.

PubMed

Nickel, Felix; Bintintan, Vasile V; Gehrig, Tobias; Kenngott, Hannes G; Fischer, Lars; Gutt, Carsten N; Müller-Stich, Beat P

2013-05-01

The purpose of the present study was to determine the value of virtual reality (VR) training for a multimodality training program of basic laparoscopic surgery. Participants in a two-day multimodality training for laparoscopic surgery used box trainers, live animal training, and cadaveric training on the pulsating organ perfusion (POP) trainer in a structured and standardized training program. The participants were divided into two groups. The VR group (n = 13) also practiced with VR training during the program, whereas the control group (n = 14) did not use VR training. The training modalities were assessed using questionnaires with a five-point Likert scale after the program. Concerning VR training, members of the control group assessed their expectations, whereas the VR group assessed the actual experience of using it. Skills performance was evaluated with five standardized test tasks in a live porcine model before (pre-test) and after (post-test) the training program. Laparoscopic skills were measured by task completion time and a general performance score for each task. Baseline tests were compared with laparoscopic experience of all participants for construct validity of the skills test. The expected benefit from VR training of the control group was higher than the experienced benefit of the VR group. Box and POP training received better ratings from the VR group than from the control group for some purposes. Both groups improved their skill parameters significantly from pre-training to post-training tests [score +17 % (P < 0.01), time -29 % (P < 0.01)]. No significant difference was found between the two groups for laparoscopic skills improvement except for the score in the instrument coordination task. Construct validity of the skills test was significant for both time and score. At its current level of performance, VR training does not meet expectations. No additional benefit was observed from VR training in our multimodality training program.

Game controller modification for fMRI hyperscanning experiments in a cooperative virtual reality environment.

PubMed

Trees, Jason; Snider, Joseph; Falahpour, Maryam; Guo, Nick; Lu, Kun; Johnson, Douglas C; Poizner, Howard; Liu, Thomas T

2014-01-01

Hyperscanning, an emerging technique in which data from multiple interacting subjects' brains are simultaneously recorded, has become an increasingly popular way to address complex topics, such as "theory of mind." However, most previous fMRI hyperscanning experiments have been limited to abstract social interactions (e.g. phone conversations). Our new method utilizes a virtual reality (VR) environment used for military training, Virtual Battlespace 2 (VBS2), to create realistic avatar-avatar interactions and cooperative tasks. To control the virtual avatar, subjects use a MRI compatible Playstation 3 game controller, modified by removing all extraneous metal components and replacing any necessary ones with 3D printed plastic models. Control of both scanners' operation is initiated by a VBS2 plugin to sync scanner time to the known time within the VR environment. Our modifications include:•Modification of game controller to be MRI compatible.•Design of VBS2 virtual environment for cooperative interactions.•Syncing two MRI machines for simultaneous recording.

Game controller modification for fMRI hyperscanning experiments in a cooperative virtual reality environment

PubMed Central

Trees, Jason; Snider, Joseph; Falahpour, Maryam; Guo, Nick; Lu, Kun; Johnson, Douglas C.; Poizner, Howard; Liu, Thomas T.

2014-01-01

Hyperscanning, an emerging technique in which data from multiple interacting subjects’ brains are simultaneously recorded, has become an increasingly popular way to address complex topics, such as “theory of mind.” However, most previous fMRI hyperscanning experiments have been limited to abstract social interactions (e.g. phone conversations). Our new method utilizes a virtual reality (VR) environment used for military training, Virtual Battlespace 2 (VBS2), to create realistic avatar-avatar interactions and cooperative tasks. To control the virtual avatar, subjects use a MRI compatible Playstation 3 game controller, modified by removing all extraneous metal components and replacing any necessary ones with 3D printed plastic models. Control of both scanners’ operation is initiated by a VBS2 plugin to sync scanner time to the known time within the VR environment. Our modifications include:•Modification of game controller to be MRI compatible.•Design of VBS2 virtual environment for cooperative interactions.•Syncing two MRI machines for simultaneous recording. PMID:26150964

Compendium of Arms Control Verification Proposals.

DTIC Science & Technology

1982-03-01

proposals. This appears to be the case for virtually all kinds of prospective arms control topics from general and complete disarmament to control of specific... virtually anywhere. Unrestricted access would be particularly necessary in the case of states which previously had nuclear weapons. Practically speaking...been transferred out of the area, it would be harder to check on remaining stocks without some intrusive inspection and it would be virtually impossible

An intelligent control and virtual display system for evolutionary space station workstation design

NASA Technical Reports Server (NTRS)

Feng, Xin; Niederjohn, Russell J.; Mcgreevy, Michael W.

1992-01-01

Research and development of the Advanced Display and Computer Augmented Control System (ADCACS) for the space station Body-Ported Cupola Virtual Workstation (BP/VCWS) were pursued. The potential applications were explored of body ported virtual display and intelligent control technology for the human-system interfacing applications is space station environment. The new system is designed to enable crew members to control and monitor a variety of space operations with greater flexibility and efficiency than existing fixed consoles. The technologies being studied include helmet mounted virtual displays, voice and special command input devices, and microprocessor based intelligent controllers. Several research topics, such as human factors, decision support expert systems, and wide field of view, color displays are being addressed. The study showed the significant advantages of this uniquely integrated display and control system, and its feasibility for human-system interfacing applications in the space station command and control environment.

Virtual decoupling flight control via real-time trajectory synthesis and tracking

NASA Astrophysics Data System (ADS)

Zhang, Xuefu

The production of the General Aviation industry has declined in the past 25 years. Ironically, however, the increasing demand for air travel as a fast, safe, and high-quality mode of transportation has been far from satisfied. Addressing this demand shortfall with personal air transportation necessitates advanced systems for navigation, guidance, control, flight management, and flight traffic control. Among them, an effective decoupling flight control system will not only improve flight quality, safety, and simplicity, and increase air space usage, but also reduce expenses on pilot initial and current training, and thus expand the current market and explore new markets. Because of the formidable difficulties encountered in the actual decoupling of non-linear, time-variant, and highly coupled flight control systems through traditional approaches, a new approach, which essentially converts the decoupling problem into a real-time trajectory synthesis and tracking problem, is employed. Then, the converted problem is solved and a virtual decoupling effect is achieved. In this approach, a trajectory in inertial space can be predefined and dynamically modified based on the flight mission and the pilot's commands. A feedforward-feedback control architecture is constructed to guide the airplane along the trajectory as precisely as possible. Through this approach, the pilot has much simpler, virtually decoupled control of the airplane in terms of speed, flight path angle and horizontal radius of curvature. To verify and evaluate this approach, extensive computer simulation is performed. A great deal of test cases are designed for the flight control under different flight conditions. The simulation results show that our decoupling strategy is satisfactory and promising, and therefore the research can serve as a consolidated foundation for future practical applications.

Development of design parameters for virtual cement and concrete testing.

DOT National Transportation Integrated Search

2013-12-01

The development, testing, and certification of new concrete mix designs is an expensive and time-consuming aspect : of the concrete industry. A software package, named the Virtual Concrete and Cement Testing Laboratory (VCCTL), : has been developed b...

Human responses to augmented virtual scaffolding models.

PubMed

Hsiao, Hongwei; Simeonov, Peter; Dotson, Brian; Ammons, Douglas; Kau, Tsui-Ying; Chiou, Sharon

2005-08-15

This study investigated the effect of adding real planks, in virtual scaffolding models of elevation, on human performance in a surround-screen virtual reality (SSVR) system. Twenty-four construction workers and 24 inexperienced controls performed walking tasks on real and virtual planks at three virtual heights (0, 6 m, 12 m) and two scaffolding-platform-width conditions (30, 60 cm). Gait patterns, walking instability measurements and cardiovascular reactivity were assessed. The results showed differences in human responses to real vs. virtual planks in walking patterns, instability score and heart-rate inter-beat intervals; it appeared that adding real planks in the SSVR virtual scaffolding model enhanced the quality of SSVR as a human - environment interface research tool. In addition, there were significant differences in performance between construction workers and the control group. The inexperienced participants were more unstable as compared to construction workers. Both groups increased their stride length with repetitions of the task, indicating a possibly confidence- or habit-related learning effect. The practical implications of this study are in the adoption of augmented virtual models of elevated construction environments for injury prevention research, and the development of programme for balance-control training to reduce the risk of falls at elevation before workers enter a construction job.

Virtual Conversation Partner for Adults with Autism

PubMed Central

Trepagnier, Cheryl Y.; Olsen, Dale E.; Bell, Corinne A.

2011-01-01

Abstract Autistic Spectrum Disorder (ASD) is notable for severely impaired reciprocal social interaction skills relative to language and intellectual abilities, presenting a major barrier to social integration and vocational success. Evidence-based interventions to address these needs are lacking. We report on the development of a small, prototype conversation simulation to teach conversational skills to adolescents and adults with ASD and average to superior intellectual abilities. We also report on a test of the feasibility and acceptability of the simulation approach with a sample of the target population. The simulation engages the user in a virtual conversation with an on-screen partner whose reactions provide naturalistic feedback geared to the appropriateness of the learner's response choices. The prototype simulation, which provides for up to 12 potentially unique multi-turn conversations, was used over a period of 2 weeks by 16 adolescents and adults who then rated statements about the system on a linear scale of 1 (disagreement) to 5 (high agreement). The participants highly endorsed the majority of positive statements about the quality and credibility of the interaction and the virtual conversation partner. In contrast, agreement with positive statements about instructional features external to the conversation was moderate. Unexpectedly, most participants strongly agreed that using the simulation had been helpful to them. Further development and testing in the context of a controlled study with randomized assignment to control and experimental groups are needed to determine whether this approach is effective in improving real-world pragmatic language behavior of high-functioning adults with ASD. PMID:21329439

A new method for aerodynamic test of high altitude propellers

NASA Astrophysics Data System (ADS)

Gong, Xiying; Zhang, Lin

A ground test system is designed for aerodynamic performance tests of high altitude propellers. The system is consisted of stable power supply, servo motors, two-component balance constructed by tension-compression sensors, ultrasonic anemometer, data acquisition module. It is loaded on a truck to simulate propellers' wind-tunnel test for different wind velocities at low density circumstance. The graphical programming language LABVIEW for developing virtual instrument is used to realize the test system control and data acquisition. Aerodynamic performance test of a propeller with 6.8 m diameter was completed by using this system. The results verify the feasibility of the ground test method.

Software platform virtualization in chemistry research and university teaching

PubMed Central

2009-01-01

Background Modern chemistry laboratories operate with a wide range of software applications under different operating systems, such as Windows, LINUX or Mac OS X. Instead of installing software on different computers it is possible to install those applications on a single computer using Virtual Machine software. Software platform virtualization allows a single guest operating system to execute multiple other operating systems on the same computer. We apply and discuss the use of virtual machines in chemistry research and teaching laboratories. Results Virtual machines are commonly used for cheminformatics software development and testing. Benchmarking multiple chemistry software packages we have confirmed that the computational speed penalty for using virtual machines is low and around 5% to 10%. Software virtualization in a teaching environment allows faster deployment and easy use of commercial and open source software in hands-on computer teaching labs. Conclusion Software virtualization in chemistry, mass spectrometry and cheminformatics is needed for software testing and development of software for different operating systems. In order to obtain maximum performance the virtualization software should be multi-core enabled and allow the use of multiprocessor configurations in the virtual machine environment. Server consolidation, by running multiple tasks and operating systems on a single physical machine, can lead to lower maintenance and hardware costs especially in small research labs. The use of virtual machines can prevent software virus infections and security breaches when used as a sandbox system for internet access and software testing. Complex software setups can be created with virtual machines and are easily deployed later to multiple computers for hands-on teaching classes. We discuss the popularity of bioinformatics compared to cheminformatics as well as the missing cheminformatics education at universities worldwide. PMID:20150997

Software platform virtualization in chemistry research and university teaching.

PubMed

Kind, Tobias; Leamy, Tim; Leary, Julie A; Fiehn, Oliver

2009-11-16

Modern chemistry laboratories operate with a wide range of software applications under different operating systems, such as Windows, LINUX or Mac OS X. Instead of installing software on different computers it is possible to install those applications on a single computer using Virtual Machine software. Software platform virtualization allows a single guest operating system to execute multiple other operating systems on the same computer. We apply and discuss the use of virtual machines in chemistry research and teaching laboratories. Virtual machines are commonly used for cheminformatics software development and testing. Benchmarking multiple chemistry software packages we have confirmed that the computational speed penalty for using virtual machines is low and around 5% to 10%. Software virtualization in a teaching environment allows faster deployment and easy use of commercial and open source software in hands-on computer teaching labs. Software virtualization in chemistry, mass spectrometry and cheminformatics is needed for software testing and development of software for different operating systems. In order to obtain maximum performance the virtualization software should be multi-core enabled and allow the use of multiprocessor configurations in the virtual machine environment. Server consolidation, by running multiple tasks and operating systems on a single physical machine, can lead to lower maintenance and hardware costs especially in small research labs. The use of virtual machines can prevent software virus infections and security breaches when used as a sandbox system for internet access and software testing. Complex software setups can be created with virtual machines and are easily deployed later to multiple computers for hands-on teaching classes. We discuss the popularity of bioinformatics compared to cheminformatics as well as the missing cheminformatics education at universities worldwide.

Testing a novel method for improving wayfinding by means of a P3b Virtual Reality Visual Paradigm in normal aging.

PubMed

de Tommaso, Marina; Ricci, Katia; Delussi, Marianna; Montemurno, Anna; Vecchio, Eleonora; Brunetti, Antonio; Bevilacqua, Vitoantonio

2016-01-01

We propose a virtual reality (VR) model, reproducing a house environment, where color modification of target places, obtainable by home automation in a real ambient, was tested by means of a P3b paradigm. The target place (bathroom door) was designed to be recognized during a virtual wayfinding in a realistic reproduction of a house environment. Different color and luminous conditions, easily obtained in the real ambient from a remote home automation control, were applied to the target and standard places, all the doors being illuminated in white (W), and only target doors colored with a green (G) or red (R) spotlight. Three different Virtual Environments (VE) were depicted, as the bathroom was designed in the aisle (A), living room (L) and bedroom (B). EEG was recorded from 57 scalp electrodes in 10 healthy subjects in the 60-80 year age range (O-old group) and 12 normal cases in the 20-30 year age range (Y-young group). In Young group, all the target stimuli determined a significant increase in P3b amplitude on the parietal, occipital and central electrodes compared to frequent stimuli condition, whatever was the color of the target door, while in elderly group the P3b obtained by the green and red colors was significantly different from the frequent stimulus, on the parietal, occipital, and central derivations, while the White stimulus did not evoke a significantly larger P3b with respect to frequent stimulus. The modulation of P3b amplitude, obtained by color and luminance change of target place, suggests that cortical resources, able to compensate the age-related progressive loss of cognitive performance, need to be facilitated even in normal elderly. The event-related responses obtained by virtual reality may be a reliable method to test the environmental feasibility to age-related cognitive changes.

Combined Cognitive-Motor Rehabilitation in Virtual Reality Improves Motor Outcomes in Chronic Stroke - A Pilot Study.

PubMed

Faria, Ana L; Cameirão, Mónica S; Couras, Joana F; Aguiar, Joana R O; Costa, Gabriel M; Bermúdez I Badia, Sergi

2018-01-01

Stroke is one of the most common causes of acquired disability, leaving numerous adults with cognitive and motor impairments, and affecting patients' capability to live independently. Virtual Reality (VR) based methods for stroke rehabilitation have mainly focused on motor rehabilitation but there is increasing interest toward the integration of cognitive training for providing more effective solutions. Here we investigate the feasibility for stroke recovery of a virtual cognitive-motor task, the Reh@Task, which combines adapted arm reaching, and attention and memory training. 24 participants in the chronic stage of stroke, with cognitive and motor deficits, were allocated to one of two groups (VR, Control). Both groups were enrolled in conventional occupational therapy, which mostly involves motor training. Additionally, the VR group underwent training with the Reh@Task and the control group performed time-matched conventional occupational therapy. Motor and cognitive competences were assessed at baseline, end of treatment (1 month) and at a 1-month follow-up through the Montreal Cognitive Assessment, Single Letter Cancelation, Digit Cancelation, Bells Test, Fugl-Meyer Assessment Test, Chedoke Arm and Hand Activity Inventory, Modified Ashworth Scale, and Barthel Index. Our results show that both groups improved in motor function over time, but the Reh@Task group displayed significantly higher between-group outcomes in the arm subpart of the Fugl-Meyer Assessment Test. Improvements in cognitive function were significant and similar in both groups. Overall, these results are supportive of the viability of VR tools that combine motor and cognitive training, such as the Reh@Task. Trial Registration: This trial was not registered because it is a small clinical study that addresses the feasibility of a prototype device.

Combined Cognitive-Motor Rehabilitation in Virtual Reality Improves Motor Outcomes in Chronic Stroke – A Pilot Study

PubMed Central

Faria, Ana L.; Cameirão, Mónica S.; Couras, Joana F.; Aguiar, Joana R. O.; Costa, Gabriel M.; Bermúdez i Badia, Sergi

2018-01-01

Stroke is one of the most common causes of acquired disability, leaving numerous adults with cognitive and motor impairments, and affecting patients’ capability to live independently. Virtual Reality (VR) based methods for stroke rehabilitation have mainly focused on motor rehabilitation but there is increasing interest toward the integration of cognitive training for providing more effective solutions. Here we investigate the feasibility for stroke recovery of a virtual cognitive-motor task, the Reh@Task, which combines adapted arm reaching, and attention and memory training. 24 participants in the chronic stage of stroke, with cognitive and motor deficits, were allocated to one of two groups (VR, Control). Both groups were enrolled in conventional occupational therapy, which mostly involves motor training. Additionally, the VR group underwent training with the Reh@Task and the control group performed time-matched conventional occupational therapy. Motor and cognitive competences were assessed at baseline, end of treatment (1 month) and at a 1-month follow-up through the Montreal Cognitive Assessment, Single Letter Cancelation, Digit Cancelation, Bells Test, Fugl-Meyer Assessment Test, Chedoke Arm and Hand Activity Inventory, Modified Ashworth Scale, and Barthel Index. Our results show that both groups improved in motor function over time, but the Reh@Task group displayed significantly higher between-group outcomes in the arm subpart of the Fugl-Meyer Assessment Test. Improvements in cognitive function were significant and similar in both groups. Overall, these results are supportive of the viability of VR tools that combine motor and cognitive training, such as the Reh@Task. Trial Registration: This trial was not registered because it is a small clinical study that addresses the feasibility of a prototype device. PMID:29899719

Virtual Reality Compared with Bench-Top Simulation in the Acquisition of Arthroscopic Skill: A Randomized Controlled Trial.

PubMed

Banaszek, Daniel; You, Daniel; Chang, Justues; Pickell, Michael; Hesse, Daniel; Hopman, Wilma M; Borschneck, Daniel; Bardana, Davide

2017-04-05

Work-hour restrictions as set forth by the Accreditation Council for Graduate Medical Education (ACGME) and other governing bodies have forced training programs to seek out new learning tools to accelerate acquisition of both medical skills and knowledge. As a result, competency-based training has become an important part of residency training. The purpose of this study was to directly compare arthroscopic skill acquisition in both high-fidelity and low-fidelity simulator models and to assess skill transfer from either modality to a cadaveric specimen, simulating intraoperative conditions. Forty surgical novices (pre-clerkship-level medical students) voluntarily participated in this trial. Baseline demographic data, as well as data on arthroscopic knowledge and skill, were collected prior to training. Subjects were randomized to 5-week independent training sessions on a high-fidelity virtual reality arthroscopic simulator or on a bench-top arthroscopic setup, or to an untrained control group. Post-training, subjects were asked to perform a diagnostic arthroscopy on both simulators and in a simulated intraoperative environment on a cadaveric knee. A more difficult surprise task was also incorporated to evaluate skill transfer. Subjects were evaluated using the Global Rating Scale (GRS), the 14-point arthroscopic checklist, and a timer to determine procedural efficiency (time per task). Secondary outcomes focused on objective measures of virtual reality simulator motion analysis. Trainees on both simulators demonstrated a significant improvement (p < 0.05) in arthroscopic skills compared with baseline scores and untrained controls, both in and ex vivo. The virtual reality simulation group consistently outperformed the bench-top model group in the diagnostic arthroscopy crossover tests and in the simulated cadaveric setup. Furthermore, the virtual reality group demonstrated superior skill transfer in the surprise skill transfer task. Both high-fidelity and low-fidelity simulation trainings were effective in arthroscopic skill acquisition. High-fidelity virtual reality simulation was superior to bench-top simulation in the acquisition of arthroscopic skills, both in the laboratory and in vivo. Further clinical investigation is needed to interpret the importance of these results.

Fused Reality for Enhanced Flight Test Capabilities

NASA Technical Reports Server (NTRS)

Bachelder, Ed; Klyde, David

2011-01-01

The feasibility of using Fused Reality-based simulation technology to enhance flight test capabilities has been investigated. In terms of relevancy to piloted evaluation, there remains no substitute for actual flight tests, even when considering the fidelity and effectiveness of modern ground-based simulators. In addition to real-world cueing (vestibular, visual, aural, environmental, etc.), flight tests provide subtle but key intangibles that cannot be duplicated in a ground-based simulator. There is, however, a cost to be paid for the benefits of flight in terms of budget, mission complexity, and safety, including the need for ground and control-room personnel, additional aircraft, etc. A Fused Reality(tm) (FR) Flight system was developed that allows a virtual environment to be integrated with the test aircraft so that tasks such as aerial refueling, formation flying, or approach and landing can be accomplished without additional aircraft resources or the risk of operating in close proximity to the ground or other aircraft. Furthermore, the dynamic motions of the simulated objects can be directly correlated with the responses of the test aircraft. The FR Flight system will allow real-time observation of, and manual interaction with, the cockpit environment that serves as a frame for the virtual out-the-window scene.

DHM simulation in virtual environments: a case-study on control room design.

PubMed

Zamberlan, M; Santos, V; Streit, P; Oliveira, J; Cury, R; Negri, T; Pastura, F; Guimarães, C; Cid, G

2012-01-01

This paper will present the workflow developed for the application of serious games in the design of complex cooperative work settings. The project was based on ergonomic studies and development of a control room among participative design process. Our main concerns were the 3D human virtual representation acquired from 3D scanning, human interaction, workspace layout and equipment designed considering ergonomics standards. Using Unity3D platform to design the virtual environment, the virtual human model can be controlled by users on dynamic scenario in order to evaluate the new work settings and simulate work activities. The results obtained showed that this virtual technology can drastically change the design process by improving the level of interaction between final users and, managers and human factors team.

Open multi-agent control architecture to support virtual-reality-based man-machine interfaces

NASA Astrophysics Data System (ADS)

Freund, Eckhard; Rossmann, Juergen; Brasch, Marcel

2001-10-01

Projective Virtual Reality is a new and promising approach to intuitively operable man machine interfaces for the commanding and supervision of complex automation systems. The user interface part of Projective Virtual Reality heavily builds on latest Virtual Reality techniques, a task deduction component and automatic action planning capabilities. In order to realize man machine interfaces for complex applications, not only the Virtual Reality part has to be considered but also the capabilities of the underlying robot and automation controller are of great importance. This paper presents a control architecture that has proved to be an ideal basis for the realization of complex robotic and automation systems that are controlled by Virtual Reality based man machine interfaces. The architecture does not just provide a well suited framework for the real-time control of a multi robot system but also supports Virtual Reality metaphors and augmentations which facilitate the user's job to command and supervise a complex system. The developed control architecture has already been used for a number of applications. Its capability to integrate sensor information from sensors of different levels of abstraction in real-time helps to make the realized automation system very responsive to real world changes. In this paper, the architecture will be described comprehensively, its main building blocks will be discussed and one realization that is built based on an open source real-time operating system will be presented. The software design and the features of the architecture which make it generally applicable to the distributed control of automation agents in real world applications will be explained. Furthermore its application to the commanding and control of experiments in the Columbus space laboratory, the European contribution to the International Space Station (ISS), is only one example which will be described.

Physical environment virtualization for human activities recognition

NASA Astrophysics Data System (ADS)

Poshtkar, Azin; Elangovan, Vinayak; Shirkhodaie, Amir; Chan, Alex; Hu, Shuowen

2015-05-01

Human activity recognition research relies heavily on extensive datasets to verify and validate performance of activity recognition algorithms. However, obtaining real datasets are expensive and highly time consuming. A physics-based virtual simulation can accelerate the development of context based human activity recognition algorithms and techniques by generating relevant training and testing videos simulating diverse operational scenarios. In this paper, we discuss in detail the requisite capabilities of a virtual environment to aid as a test bed for evaluating and enhancing activity recognition algorithms. To demonstrate the numerous advantages of virtual environment development, a newly developed virtual environment simulation modeling (VESM) environment is presented here to generate calibrated multisource imagery datasets suitable for development and testing of recognition algorithms for context-based human activities. The VESM environment serves as a versatile test bed to generate a vast amount of realistic data for training and testing of sensor processing algorithms. To demonstrate the effectiveness of VESM environment, we present various simulated scenarios and processed results to infer proper semantic annotations from the high fidelity imagery data for human-vehicle activity recognition under different operational contexts.

The Effect of Virtual Reality on Pain in Primiparity Women during Episiotomy Repair: A Randomize Clinical Trial

PubMed Central

JahaniShoorab, Nahid; Ebrahimzadeh Zagami, Samira; Nahvi, Ali; Mazluom, Seyed Reza; Golmakani, Nahid; Talebi, Mahdi; Pabarja, Ferial

2015-01-01

Background Pain is one of the side effects of episiotomy. The virtual reality (VR) is a non-pharmacological method for pain relief. The purpose of this study was to determine the effect of using video glasses on pain reduction in primiparity women during episiotomy repair. Methods This clinical trial was conducted on 30 primiparous parturient women having labor at Omolbanin Hospital (Mashhad, Iran) during May-July 2012. Samples during episiotomy repair were randomly divided into two equal groups. The intervention group received the usual treatment with VR (video glasses and local infiltration 5 ml solution of lidocaine 2%) and the control group only received local infiltration (5 ml solution of lidocaine 2%). Pain was measured using the Numeric Pain Rating Scale (0-100 scale) before, during and after the episiotomy repair. Data were analyzed using Fisher’s exact test, Chi-square, Mann-Whitney and repeated measures ANOVA tests by SPSS 11.5 software. Results There were statistically significant differences between the pain score during episiotomy repair in both groups (P=0.038). Conclusion Virtual reality is an effective complementary non-pharmacological method to reduce pain during episiotomy repair. Trial Registration Number: IRCT138811063185N1. PMID:25999621

Online virtual-patient cases versus traditional problem-based learning in advanced pharmacy practice experiences.

PubMed

Al-Dahir, Sara; Bryant, Kendrea; Kennedy, Kathleen B; Robinson, Donna S

2014-05-15

To evaluate the efficacy of faculty-led problem-based learning (PBL) vs online simulated-patient case in fourth-year (P4) pharmacy students. Fourth-year pharmacy students were randomly assigned to participate in either online branched-case learning using a virtual simulation platform or a small-group discussion. Preexperience and postexperience student assessments and a survey instrument were completed. While there were no significant differences in the preexperience test scores between the groups, there was a significant increase in scores in both the virtual-patient group and the PBL group between the preexperience and postexperience tests. The PBL group had higher postexperience test scores (74.8±11.7) than did the virtual-patient group (66.5±13.6) (p=0.001). The PBL method demonstrated significantly greater improvement in postexperience test scores than did the virtual-patient method. Both were successful learning methods, suggesting that a diverse approach to simulated patient cases may reach more student learning styles.

An exploratory fNIRS study with immersive virtual reality: a new method for technical implementation

PubMed Central

Seraglia, Bruno; Gamberini, Luciano; Priftis, Konstantinos; Scatturin, Pietro; Martinelli, Massimiliano; Cutini, Simone

2011-01-01

For over two decades Virtual Reality (VR) has been used as a useful tool in several fields, from medical and psychological treatments, to industrial and military applications. Only in recent years researchers have begun to study the neural correlates that subtend VR experiences. Even if the functional Magnetic Resonance Imaging (fMRI) is the most common and used technique, it suffers several limitations and problems. Here we present a methodology that involves the use of a new and growing brain imaging technique, functional Near-infrared Spectroscopy (fNIRS), while participants experience immersive VR. In order to allow a proper fNIRS probe application, a custom-made VR helmet was created. To test the adapted helmet, a virtual version of the line bisection task was used. Participants could bisect the lines in a virtual peripersonal or extrapersonal space, through the manipulation of a Nintendo Wiimote ® controller in order for the participants to move a virtual laser pointer. Although no neural correlates of the dissociation between peripersonal and extrapersonal space were found, a significant hemodynamic activity with respect to the baseline was present in the right parietal and occipital areas. Both advantages and disadvantages of the presented methodology are discussed. PMID:22207843

Development and Use of a Virtual NMR Facility

NASA Astrophysics Data System (ADS)

Keating, Kelly A.; Myers, James D.; Pelton, Jeffrey G.; Bair, Raymond A.; Wemmer, David E.; Ellis, Paul D.

2000-03-01

We have developed a "virtual NMR facility" (VNMRF) to enhance access to the NMR spectrometers in Pacific Northwest National Laboratory's Environmental Molecular Sciences Laboratory (EMSL). We use the term virtual facility to describe a real NMR facility made accessible via the Internet. The VNMRF combines secure remote operation of the EMSL's NMR spectrometers over the Internet with real-time videoconferencing, remotely controlled laboratory cameras, real-time computer display sharing, a Web-based electronic laboratory notebook, and other capabilities. Remote VNMRF users can see and converse with EMSL researchers, directly and securely control the EMSL spectrometers, and collaboratively analyze results. A customized Electronic Laboratory Notebook allows interactive Web-based access to group notes, experimental parameters, proposed molecular structures, and other aspects of a research project. This paper describes our experience developing a VNMRF and details the specific capabilities available through the EMSL VNMRF. We show how the VNMRF has evolved during a test project and present an evaluation of its impact in the EMSL and its potential as a model for other scientific facilities. All Collaboratory software used in the VNMRF is freely available from http://www.emsl.pnl.gov:2080/docs/collab.

The effect of contextual auditory stimuli on virtual spatial navigation in patients with focal hemispheric lesions.

PubMed

Cogné, Mélanie; Knebel, Jean-François; Klinger, Evelyne; Bindschaedler, Claire; Rapin, Pierre-André; Joseph, Pierre-Alain; Clarke, Stephanie

2018-01-01

Topographical disorientation is a frequent deficit among patients suffering from brain injury. Spatial navigation can be explored in this population using virtual reality environments, even in the presence of motor or sensory disorders. Furthermore, the positive or negative impact of specific stimuli can be investigated. We studied how auditory stimuli influence the performance of brain-injured patients in a navigational task, using the Virtual Action Planning-Supermarket (VAP-S) with the addition of contextual ("sonar effect" and "name of product") and non-contextual ("periodic randomised noises") auditory stimuli. The study included 22 patients with a first unilateral hemispheric brain lesion and 17 healthy age-matched control subjects. After a software familiarisation, all subjects were tested without auditory stimuli, with a sonar effect or periodic random sounds in a random order, and with the stimulus "name of product". Contextual auditory stimuli improved patient performance more than control group performance. Contextual stimuli benefited most patients with severe executive dysfunction or with severe unilateral neglect. These results indicate that contextual auditory stimuli are useful in the assessment of navigational abilities in brain-damaged patients and that they should be used in rehabilitation paradigms.

The ecological and construct validity of a newly developed measure of executive function: the Virtual Library Task.

PubMed

Renison, Belinda; Ponsford, Jennie; Testa, Renee; Richardson, Barry; Brownfield, Kylie

2012-05-01

Virtual reality (VR) assessment paradigms have the potential to address the limited ecological validity of pen and paper measures of executive function (EF) and the pragmatic and reliability issues associated with functional measures. To investigate the ecological validity and construct validity of a newly developed VR measure of EF, the Virtual Library Task (VLT); a real life analogous task--the Real Library Task (RLT); and five neuropsychological measures of EF were administered to 30 patients with traumatic brain injury (TBI) and 30 healthy Controls. Significant others for each participant also completed the Dysexecutive Questionnaire (DEX), which is a behavioral rating scale of everyday EF. Performances on the VLT and the RLT were significantly positively correlated indicating that VR performance is similar to real world performance. The TBI group performed significantly worse than the Control group on the VLT and the Modified Six Elements Test (MSET) but the other four neuropsychological measures of EF failed to differentiate the groups. Both the MSET and the VLT significantly predicted everyday EF suggesting that they are both ecologically valid tools for the assessment of EF. The VLT has the advantage over the MSET of providing objective measurement of individual components of EF.

The effects of virtual experience on attitudes toward real brands.

PubMed

Dobrowolski, Pawel; Pochwatko, Grzegorz; Skorko, Maciek; Bielecki, Maksymilian

2014-02-01

Although the commercial availability and implementation of virtual reality interfaces has seen rapid growth in recent years, little research has been conducted on the potential for virtual reality to affect consumer behavior. One unaddressed issue is how our real world attitudes are affected when we have a virtual experience with the target of those attitudes. This study compared participant (N=60) attitudes toward car brands before and after a virtual test drive of those cars was provided. Results indicated that attitudes toward test brands changed after experience with virtual representations of those brands. Furthermore, manipulation of the quality of this experience (in this case modification of driving difficulty) was reflected in the direction of attitude change. We discuss these results in the context of the associative-propositional evaluation model.

Virtual agents in a simulated virtual training environment

NASA Technical Reports Server (NTRS)

Achorn, Brett; Badler, Norman L.

1993-01-01

A drawback to live-action training simulations is the need to gather a large group of participants in order to train a few individuals. One solution to this difficulty is the use of computer-controlled agents in a virtual training environment. This allows a human participant to be replaced by a virtual, or simulated, agent when only limited responses are needed. Each agent possesses a specified set of behaviors and is capable of limited autonomous action in response to its environment or the direction of a human trainee. The paper describes these agents in the context of a simulated hostage rescue training session, involving two human rescuers assisted by three virtual (computer-controlled) agents and opposed by three other virtual agents.

The use of virtual reality computer simulation in learning Port-A cath injection.

PubMed

Tsai, Sing-Ling; Chai, Sin-Kuo; Hsieh, Li-Feng; Lin, Shirling; Taur, Fang-Meei; Sung, Wen-Hsu; Doong, Ji-Liang

2008-03-01

Cost-benefit management trends in Taiwan healthcare settings have led nurses to perform more invasive skills, such as Port-A cath administration of medications. Accordingly, nurses must be well-prepared prior to teaching by the mentor and supervision method. The purpose of the current study was to develop a computer-assisted protocol using virtual reality (VR) in performing Port-A cath as a training program for novice nurses. A pre-tested and post-tested control group experimental design was used in this study. Seventy-seven novice nurses were invited from one large medical center hospital in North Taiwan. Thirty-seven and forty nurses were randomly assigned to experimental and control groups. First, we designed a 40 minute port-A cath injection VR simulation. Then, the experimental group practiced this simulation two times over 3 weeks. The control group attended the traditional class. The post-test 1 was right after completion of the simulation practice. The post-test 2 was after the second simulation practice in 3 weeks. The results showed that most novice nurses lacked Port-A cath experience both in the classroom and during the period of their practice training. The knowledge score regarding the Port-A cath technique was significantly higher in the nurses that participated in the simulation training than in the control group. The novice nurses were most satisfied with the reduction in their fear of performing the Port-A cath technique and their enhanced clinical skills. VR simulation significantly reduced error rates and increased correct equipment selection, showing that nurses who participated in the simulation may be better prepared for inserting Port-A cath.

Virtual reality system for treatment of the fear of public speaking using image-based rendering and moving pictures.

PubMed

Lee, Jae M; Ku, Jeong H; Jang, Dong P; Kim, Dong H; Choi, Young H; Kim, In Y; Kim, Sun I

2002-06-01

The fear of speaking is often cited as the world's most common social phobia. The rapid growth of computer technology enabled us to use virtual reality (VR) for the treatment of the fear of public speaking. There have been two techniques used to construct a virtual environment for the treatment of the fear of public speaking: model-based and movie-based. Virtual audiences and virtual environments made by model-based technique are unrealistic and unnatural. The movie-based technique has a disadvantage in that each virtual audience cannot be controlled respectively, because all virtual audiences are included in one moving picture file. To address this disadvantage, this paper presents a virtual environment made by using image-based rendering (IBR) and chroma keying simultaneously. IBR enables us to make the virtual environment realistic because the images are stitched panoramically with the photos taken from a digital camera. And the use of chroma keying allows a virtual audience to be controlled individually. In addition, a real-time capture technique was applied in constructing the virtual environment to give the subjects more interaction, in that they can talk with a therapist or another subject.

Catching fly balls in virtual reality: a critical test of the outfielder problem.

PubMed

Fink, Philip W; Foo, Patrick S; Warren, William H

2009-12-14

How does a baseball outfielder know where to run to catch a fly ball? The "outfielder problem" remains unresolved, and its solution would provide a window into the visual control of action. It may seem obvious that human action is based on an internal model of the physical world, such that the fielder predicts the landing point based on a mental model of the ball's trajectory (TP). However, two alternative theories, Optical Acceleration Cancellation (OAC) and Linear Optical Trajectory (LOT), propose that fielders are led to the right place at the right time by coupling their movements to visual information in a continuous "online" manner. All three theories predict successful catches and similar running paths. We provide a critical test by using virtual reality to perturb the vertical motion of the ball in mid-flight. The results confirm the predictions of OAC but are at odds with LOT and TP.

Design and evaluation of a simulation for pediatric dentistry in virtual worlds.

PubMed

Papadopoulos, Lazaros; Pentzou, Afroditi-Evaggelia; Louloudiadis, Konstantinos; Tsiatsos, Thrasyvoulos-Konstantinos

2013-10-29

Three-dimensional virtual worlds are becoming very popular among educators in the medical field. Virtual clinics and patients are already used for case study and role play in both undergraduate and continuing education levels. Dental education can also take advantage of the virtual world's pedagogical features in order to give students the opportunity to interact with virtual patients (VPs) and practice in treatment planning. The objective of this study was to design and evaluate a virtual patient as a supplemental teaching tool for pediatric dentistry. A child VP, called Erietta, was created by utilizing the programming and building tools that online virtual worlds offer. The case is about an eight-year old girl visiting the dentist with her mother for the first time. Communication techniques such as Tell-Show-Do and parents' interference management were the basic elements of the educational scenario on which the VP was based. An evaluation of the simulation was made by 103 dental students in their fourth year of study. Two groups were formed: an experimental group which was exposed to the simulation (n=52) and a control group which did not receive the simulation (n=51). At the end, both groups were asked to complete a knowledge questionnaire and the results were compared. A statistically significant difference between the two groups was found by applying a t test for independent samples (P<.001), showing a positive learning effect from the VP. The majority of the participants evaluated the aspects of the simulation very positively while 69% (36/52) of the simulation group expressed their preference for using this module as an additional teaching tool. This study demonstrated that a pediatric dentistry VP built in a virtual world offers significant learning potential when used as a supplement to the traditional teaching techniques.

Virtual grasping: closed-loop force control using electrotactile feedback.

PubMed

Jorgovanovic, Nikola; Dosen, Strahinja; Djozic, Damir J; Krajoski, Goran; Farina, Dario

2014-01-01

Closing the control loop by providing somatosensory feedback to the user of a prosthesis is a well-known, long standing challenge in the field of prosthetics. Various approaches have been investigated for feedback restoration, ranging from direct neural stimulation to noninvasive sensory substitution methods. Although there are many studies presenting closed-loop systems, only a few of them objectively evaluated the closed-loop performance, mostly using vibrotactile stimulation. Importantly, the conclusions about the utility of the feedback were partly contradictory. The goal of the current study was to systematically investigate the capability of human subjects to control grasping force in closed loop using electrotactile feedback. We have developed a realistic experimental setup for virtual grasping, which operated in real time, included a set of real life objects, as well as a graphical and dynamical model of the prosthesis. We have used the setup to test 10 healthy, able bodied subjects to investigate the role of training, feedback and feedforward control, robustness of the closed loop, and the ability of the human subjects to generalize the control to previously "unseen" objects. Overall, the outcomes of this study are very optimistic with regard to the benefits of feedback and reveal various, practically relevant, aspects of closed-loop control.

A Study Comparing the Pedagogical Effectiveness of Virtual Worlds and of Classical Methods

DTIC Science & Technology

2014-08-01

Approved for public release; distribution is unlimited. A Study Comparing the Pedagogical Effectiveness of Virtual Worlds and of Classical Methods...ABSTRACT A Study Comparing the Pedagogical Effectiveness of Virtual Worlds and of Classical Methods Report Title This experiment tests whether a virtual... PEDAGOGICAL EFFECTIVENESS OF VIRTUAL WORLDS AND OF TRADITIONAL TRAINING METHODS A Thesis by BENJAMIN PETERS

Development of a cognitive function test using virtual reality technology: examination in healthy participants.

PubMed

Sakai, Hiromi; Nagano, Akinori; Seki, Keiko; Okahashi, Sayaka; Kojima, Maki; Luo, Zhiwei

2018-07-01

We developed a virtual reality test to assess the cognitive function of Japanese people in near-daily-life environment, namely, a virtual shopping test (VST). In this test, participants were asked to execute shopping tasks using touch panel operations in a "virtual shopping mall." We examined differences in VST performances among healthy participants of different ages and correlations between VST and screening tests, such as the Mini-Mental State Examination (MMSE) and Everyday Memory Checklist (EMC). We included 285 healthy participants between 20 and 86 years of age in seven age groups. Therefore, each VST index tended to decrease with advancing age; differences among age groups were significant. Most VST indices had a significantly negative correlation with MMSE and significantly positive correlation with EMC. VST may be useful for assessing general cognitive decline; effects of age must be considered for proper interpretation of the VST scores.

So ware-Defined Network Solutions for Science Scenarios: Performance Testing Framework and Measurements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Settlemyer, Bradley; Kettimuthu, R.; Boley, Josh

High-performance scientific work flows utilize supercomputers, scientific instruments, and large storage systems. Their executions require fast setup of a small number of dedicated network connections across the geographically distributed facility sites. We present Software-Defined Network (SDN) solutions consisting of site daemons that use dpctl, Floodlight, ONOS, or OpenDaylight controllers to set up these connections. The development of these SDN solutions could be quite disruptive to the infrastructure, while requiring a close coordination among multiple sites; in addition, the large number of possible controller and device combinations to investigate could make the infrastructure unavailable to regular users for extended periods ofmore » time. In response, we develop a Virtual Science Network Environment (VSNE) using virtual machines, Mininet, and custom scripts that support the development, testing, and evaluation of SDN solutions, without the constraints and expenses of multi-site physical infrastructures; furthermore, the chosen solutions can be directly transferred to production deployments. By complementing VSNE with a physical testbed, we conduct targeted performance tests of various SDN solutions to help choose the best candidates. In addition, we propose a switching response method to assess the setup times and throughput performances of different SDN solutions, and present experimental results that show their advantages and limitations.« less

The Validity of Virtual Environments for Eliciting Emotional Responses in Patients with Eating Disorders and in Controls

ERIC Educational Resources Information Center

Ferrer-Garcia, Marta; Gutierrez-Maldonado, Jose; Caqueo-Urizar, Alejandra; Moreno, Elena

2009-01-01

This article explores the efficacy of virtual environments representing situations that are emotionally significant to patients with eating disorders (ED) to modify depression and anxiety levels both in these patients and in controls. Eighty-five ED patients and 108 students were randomly exposed to five experimental virtual environments (a…

Innovative Assessment of Aviation English in a Virtual World: Windows into Cognitive and Metacognitive Strategies

ERIC Educational Resources Information Center

Park, Moonyoung

2018-01-01

Aviation English proficiency is a core competency in the global air traffic controller profession. There is, however, growing concern about the current ineffective paper-based assessment methods and the severe lack of interactive online testing for such a critical profession, one that should be ideally assessed in an authentic task and situation…

Ivins talks on the Softphone OCA system from Atlantis' MDK

NASA Image and Video Library

2001-02-07

STS098-345-001 (7-20 February 2001) --- Astronaut Marsha S. Ivins, STS-98 mission specialist, places a phone call to Houston’s Mission Control Center (MCC) with the “virtual phone.” This test is designed to demonstrate communications capability of a new upgrade utilizing the existing Shuttle Orbiter Communications Adapter (OCA) infrastructure.

Visuospatial skills and computer game experience influence the performance of virtual endoscopy.

PubMed

Enochsson, Lars; Isaksson, Bengt; Tour, René; Kjellin, Ann; Hedman, Leif; Wredmark, Torsten; Tsai-Felländer, Li

2004-11-01

Advanced medical simulators have been introduced to facilitate surgical and endoscopic training and thereby improve patient safety. Residents trained in the Procedicus Minimally Invasive Surgical Trainer-Virtual Reality (MIST-VR) laparoscopic simulator perform laparoscopic cholecystectomy safer and faster than a control group. Little has been reported regarding whether factors like gender, computer experience, and visuospatial tests can predict the performance with a medical simulator. Our aim was to investigate whether such factors influence the performance of simulated gastroscopy. Seventeen medical students were asked about computer gaming experiences. Before virtual endoscopy, they performed the visuospatial test PicCOr, which discriminates the ability of the tested person to create a three-dimensional image from a two-dimensional presentation. Each student performed one gastroscopy (level 1, case 1) in the GI Mentor II, Simbionix, and several variables related to performance were registered. Percentage of time spent with a clear view in the endoscope correlated well with the performance on the PicSOr test (r = 0.56, P < 0.001). Efficiency of screening also correlated with PicSOr (r = 0.23, P < 0.05). In students with computer gaming experience, the efficiency of screening increased (33.6% +/- 3.1% versus 22.6% +/- 2.8%, P < 0.05) and the duration of the examination decreased by 1.5 minutes (P < 0.05). A similar trend was seen in men compared with women. The visuospatial test PicSOr predicts the results with the endoscopic simulator GI Mentor II. Two-dimensional image experience, as in computer games, also seems to affect the outcome.

Student performance and appreciation using 3D vs. 2D vision in a virtual learning environment.

PubMed

de Boer, I R; Wesselink, P R; Vervoorn, J M

2016-08-01

The aim of this study was to investigate the differences in the performance and appreciation of students working in a virtual learning environment with two (2D)- or three (3D)-dimensional vision. One hundred and twenty-four randomly divided first-year dental students performed a manual dexterity exercise on the Simodont dental trainer with an automatic assessment. Group 1 practised in 2D vision and Group 2 in 3D. All of the students practised five times for 45 min and then took a test using the vision they had practised in. After test 1, all of the students switched the type of vision to control for the learning curve: Group 1 practised in 3D and took a test in 3D, whilst Group 2 practised in 2D and took the test in 2D. To pass, three of five exercises had to be successfully completed within a time limit. The students filled out a questionnaire after completing test 2. The results show that students working with 3D vision achieved significantly better results than students who worked in 2D. Ninety-five per cent of the students filled out the questionnaire, and over 90 per cent preferred 3D vision. The use of 3D vision in a virtual learning environment has a significant positive effect on the performance of the students as well as on their appreciation of the environment. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

A four-dimensional virtual hand brain-machine interface using active dimension selection

NASA Astrophysics Data System (ADS)

Rouse, Adam G.

2016-06-01

Objective. Brain-machine interfaces (BMI) traditionally rely on a fixed, linear transformation from neural signals to an output state-space. In this study, the assumption that a BMI must control a fixed, orthogonal basis set was challenged and a novel active dimension selection (ADS) decoder was explored. Approach. ADS utilizes a two stage decoder by using neural signals to both (i) select an active dimension being controlled and (ii) control the velocity along the selected dimension. ADS decoding was tested in a monkey using 16 single units from premotor and primary motor cortex to successfully control a virtual hand avatar to move to eight different postures. Main results. Following training with the ADS decoder to control 2, 3, and then 4 dimensions, each emulating a grasp shape of the hand, performance reached 93% correct with a bit rate of 2.4 bits s-1 for eight targets. Selection of eight targets using ADS control was more efficient, as measured by bit rate, than either full four-dimensional control or computer assisted one-dimensional control. Significance. ADS decoding allows a user to quickly and efficiently select different hand postures. This novel decoding scheme represents a potential method to reduce the complexity of high-dimension BMI control of the hand.

A four-dimensional virtual hand brain-machine interface using active dimension selection

PubMed Central

Rouse, Adam G.

2018-01-01

Objective Brain-machine interfaces (BMI) traditionally rely on a fixed, linear transformation from neural signals to an output state-space. In this study, the assumption that a BMI must control a fixed, orthogonal basis set was challenged and a novel active dimension selection (ADS) decoder was explored. Approach ADS utilizes a two stage decoder by using neural signals to both i) select an active dimension being controlled and ii) control the velocity along the selected dimension. ADS decoding was tested in a monkey using 16 single units from premotor and primary motor cortex to successfully control a virtual hand avatar to move to eight different postures. Main Results Following training with the ADS decoder to control 2, 3, and then 4 dimensions, each emulating a grasp shape of the hand, performance reached 93% correct with a bit rate of 2.4 bits/s for eight targets. Selection of eight targets using ADS control was more efficient, as measured by bit rate, than either full four-dimensional control or computer assisted one-dimensional control. Significance ADS decoding allows a user to quickly and efficiently select different hand postures. This novel decoding scheme represents a potential method to reduce the complexity of high-dimension BMI control of the hand. PMID:27171896

Decision Making and Cognitive Behavioral Flexibility in a OCD Sample: a Study in a Virtual Environment.

PubMed

la Paglia, Filippo; la Cascia, Caterina; Rizzo, Rosalinda; Riva, Giuseppe; la Barbera, Daniele

2015-01-01

Neuropsychological disorders are common in Obsessive-Compulsive Disorder (OCD) patients. Executive functions, verbal fluency and verbal memory, shifting attention from one aspect of stimuli to others, mental flexibility, engaging in executive planning and decision making, are the most involved cognitive domains. We focus on two aspects of neuropsychological function: decision making and cognitive behavioral flexibility, assessed through a virtual version of the Multiple Errand Test (V-MET), developed using the NeuroVR software. Thirty OCD patients were compared with thirty matched control subjects. The results showed the presence of difficulties in OCD patients with tasks where the goal is not clear, the information is incomplete or the parameters are ill-defined.

Controlling social stress in virtual reality environments.

PubMed

Hartanto, Dwi; Kampmann, Isabel L; Morina, Nexhmedin; Emmelkamp, Paul G M; Neerincx, Mark A; Brinkman, Willem-Paul

2014-01-01

Virtual reality exposure therapy has been proposed as a viable alternative in the treatment of anxiety disorders, including social anxiety disorder. Therapists could benefit from extensive control of anxiety eliciting stimuli during virtual exposure. Two stimuli controls are studied in this study: the social dialogue situation, and the dialogue feedback responses (negative or positive) between a human and a virtual character. In the first study, 16 participants were exposed in three virtual reality scenarios: a neutral virtual world, blind date scenario, and job interview scenario. Results showed a significant difference between the three virtual scenarios in the level of self-reported anxiety and heart rate. In the second study, 24 participants were exposed to a job interview scenario in a virtual environment where the ratio between negative and positive dialogue feedback responses of a virtual character was systematically varied on-the-fly. Results yielded that within a dialogue the more positive dialogue feedback resulted in less self-reported anxiety, lower heart rate, and longer answers, while more negative dialogue feedback of the virtual character resulted in the opposite. The correlations between on the one hand the dialogue stressor ratio and on the other hand the means of SUD score, heart rate and audio length in the eight dialogue conditions showed a strong relationship: r(6) = 0.91, p = 0.002; r(6) = 0.76, p = 0.028 and r(6) = -0.94, p = 0.001 respectively. Furthermore, more anticipatory anxiety reported before exposure was found to coincide with more self-reported anxiety, and shorter answers during the virtual exposure. These results demonstrate that social dialogues in a virtual environment can be effectively manipulated for therapeutic purposes.

Controlling Social Stress in Virtual Reality Environments

PubMed Central

Hartanto, Dwi; Kampmann, Isabel L.; Morina, Nexhmedin; Emmelkamp, Paul G. M.; Neerincx, Mark A.; Brinkman, Willem-Paul

2014-01-01

Virtual reality exposure therapy has been proposed as a viable alternative in the treatment of anxiety disorders, including social anxiety disorder. Therapists could benefit from extensive control of anxiety eliciting stimuli during virtual exposure. Two stimuli controls are studied in this study: the social dialogue situation, and the dialogue feedback responses (negative or positive) between a human and a virtual character. In the first study, 16 participants were exposed in three virtual reality scenarios: a neutral virtual world, blind date scenario, and job interview scenario. Results showed a significant difference between the three virtual scenarios in the level of self-reported anxiety and heart rate. In the second study, 24 participants were exposed to a job interview scenario in a virtual environment where the ratio between negative and positive dialogue feedback responses of a virtual character was systematically varied on-the-fly. Results yielded that within a dialogue the more positive dialogue feedback resulted in less self-reported anxiety, lower heart rate, and longer answers, while more negative dialogue feedback of the virtual character resulted in the opposite. The correlations between on the one hand the dialogue stressor ratio and on the other hand the means of SUD score, heart rate and audio length in the eight dialogue conditions showed a strong relationship: r(6) = 0.91, p = 0.002; r(6) = 0.76, p = 0.028 and r(6) = −0.94, p = 0.001 respectively. Furthermore, more anticipatory anxiety reported before exposure was found to coincide with more self-reported anxiety, and shorter answers during the virtual exposure. These results demonstrate that social dialogues in a virtual environment can be effectively manipulated for therapeutic purposes. PMID:24671006

Performance on a virtual reality angled laparoscope task correlates with spatial ability of trainees.

PubMed

Rosenthal, Rachel; Hamel, Christian; Oertli, Daniel; Demartines, Nicolas; Gantert, Walter A

2010-08-01

The aim of the present study was to investigate whether trainees' performance on a virtual reality angled laparoscope navigation task correlates with scores obtained on a validated conventional test of spatial ability. 56 participants of a surgery workshop performed an angled laparoscope navigation task on the Xitact LS 500 virtual reality Simulator. Performance parameters were correlated with the score of a validated paper-and-pencil test of spatial ability. Performance at the conventional spatial ability test significantly correlated with performance at the virtual reality task for overall task score (p < 0.001), task completion time (p < 0.001) and economy of movement (p = 0.035), not for endoscope travel speed (p = 0.947). In conclusion, trainees' performance in a standardized virtual reality camera navigation task correlates with their innate spatial ability. This VR session holds potential to serve as an assessment tool for trainees.

Visual field examination method using virtual reality glasses compared with the Humphrey perimeter.

PubMed

Tsapakis, Stylianos; Papaconstantinou, Dimitrios; Diagourtas, Andreas; Droutsas, Konstantinos; Andreanos, Konstantinos; Moschos, Marilita M; Brouzas, Dimitrios

2017-01-01

To present a visual field examination method using virtual reality glasses and evaluate the reliability of the method by comparing the results with those of the Humphrey perimeter. Virtual reality glasses, a smartphone with a 6 inch display, and software that implements a fast-threshold 3 dB step staircase algorithm for the central 24° of visual field (52 points) were used to test 20 eyes of 10 patients, who were tested in a random and consecutive order as they appeared in our glaucoma department. The results were compared with those obtained from the same patients using the Humphrey perimeter. High correlation coefficient ( r =0.808, P <0.0001) was found between the virtual reality visual field test and the Humphrey perimeter visual field. Visual field examination results using virtual reality glasses have a high correlation with the Humphrey perimeter allowing the method to be suitable for probable clinical use.

Results of a massive experiment on virtual currency endowments and money demand.

PubMed

Živić, Nenad; Andjelković, Igor; Özden, Tolga; Dekić, Milovan; Castronova, Edward

2017-01-01

We use a 575,000-subject, 28-day experiment to investigate monetary policy in a virtual setting. The experiment tests the effect of virtual currency endowments on player retention and virtual currency demand. An increase in endowments of a virtual currency should lower the demand for the currency in the short run. However, in the long run, we would expect money demand to rise in response to inflation in the virtual world. We test for this behavior in a virtual field experiment in the football management game Top11. 575,000 players were selected at random and allocated to different "shards" or versions of the world. The shards differed only in terms of the initial money endowment offered to new players. Money demand was observed for 28 days as players used real money to purchase additional virtual currency. The results indicate that player money purchases were significantly higher in the shards where higher endowments were given. This suggests that a positive change in the money supply in a virtual context leads to inflation and increased money demand, and does so much more quickly than in real-world economies. Differences between virtual and real currency behavior will become more interesting as virtual currency becomes a bigger part of the real economy.

Results of a massive experiment on virtual currency endowments and money demand

PubMed Central

Živić, Nenad; Andjelković, Igor; Özden, Tolga; Dekić, Milovan

2017-01-01

We use a 575,000-subject, 28-day experiment to investigate monetary policy in a virtual setting. The experiment tests the effect of virtual currency endowments on player retention and virtual currency demand. An increase in endowments of a virtual currency should lower the demand for the currency in the short run. However, in the long run, we would expect money demand to rise in response to inflation in the virtual world. We test for this behavior in a virtual field experiment in the football management game Top11. 575,000 players were selected at random and allocated to different “shards” or versions of the world. The shards differed only in terms of the initial money endowment offered to new players. Money demand was observed for 28 days as players used real money to purchase additional virtual currency. The results indicate that player money purchases were significantly higher in the shards where higher endowments were given. This suggests that a positive change in the money supply in a virtual context leads to inflation and increased money demand, and does so much more quickly than in real-world economies. Differences between virtual and real currency behavior will become more interesting as virtual currency becomes a bigger part of the real economy. PMID:29045494

Simulation of patient encounters using a virtual patient in periodontology instruction of dental students: design, usability, and learning effect in history-taking skills.

PubMed

Schittek Janda, M; Mattheos, N; Nattestad, A; Wagner, A; Nebel, D; Färbom, C; Lê, D-H; Attström, R

2004-08-01

Simulations are important educational tools in the development of health care competence. This study describes a virtual learning environment (VLE) for diagnosis and treatment planning in oral health care. The VLE is a web-based, database application where the learner uses free text communication on the screen to interact with patient data. The VLE contains forms for history taking, clinical images, clinical data and X-rays. After reviewing the patient information, the student proposes therapy and makes prognostic evaluations of the case in free text. A usability test of the application was performed with seven dental students. The usability test showed that the software responded with correct answers to the majority of the free text questions. The application is generic in its basic functions and can be adapted to other dental or medical subject areas. A randomised controlled trial was carried out with 39 students who attended instruction in history taking with problem-based learning cases, lectures and seminars. In addition, 16 of the 39 students were randomly chosen to practise history taking using the virtual patient prior to their first patient encounter. The performance of each student was recorded on video during the patient sessions. The type and order of the questions asked by the student and the degree of empathy displayed towards the patient were analysed systematically on the videos. The data indicate that students who also undertook history taking with a virtual patient asked more relevant questions, spent more time on patient issues, and performed a more complete history interview compared with students who had only undergone standard teaching. The students who had worked with the virtual patient also seemed to have more empathy for the patients than the students who had not. The practising of history taking with a virtual patient appears to improve the capability of dental students to take a relevant oral health history.

Generation of "virtual" control groups for single arm prostate cancer adjuvant trials.

PubMed

Jia, Zhenyu; Lilly, Michael B; Koziol, James A; Chen, Xin; Xia, Xiao-Qin; Wang, Yipeng; Skarecky, Douglas; Sutton, Manuel; Sawyers, Anne; Ruckle, Herbert; Carpenter, Philip M; Wang-Rodriguez, Jessica; Jiang, Jun; Deng, Mingsen; Pan, Cong; Zhu, Jian-Guo; McLaren, Christine E; Gurley, Michael J; Lee, Chung; McClelland, Michael; Ahlering, Thomas; Kattan, Michael W; Mercola, Dan

2014-01-01

It is difficult to construct a control group for trials of adjuvant therapy (Rx) of prostate cancer after radical prostatectomy (RP) due to ethical issues and patient acceptance. We utilized 8 curve-fitting models to estimate the time to 60%, 65%, … 95% chance of progression free survival (PFS) based on the data derived from Kattan post-RP nomogram. The 8 models were systematically applied to a training set of 153 post-RP cases without adjuvant Rx to develop 8 subsets of cases (reference case sets) whose observed PFS times were most accurately predicted by each model. To prepare a virtual control group for a single-arm adjuvant Rx trial, we first select the optimal model for the trial cases based on the minimum weighted Euclidean distance between the trial case set and the reference case set in terms of clinical features, and then compare the virtual PFS times calculated by the optimum model with the observed PFSs of the trial cases by the logrank test. The method was validated using an independent dataset of 155 post-RP patients without adjuvant Rx. We then applied the method to patients on a Phase II trial of adjuvant chemo-hormonal Rx post RP, which indicated that the adjuvant Rx is highly effective in prolonging PFS after RP in patients at high risk for prostate cancer recurrence. The method can accurately generate control groups for single-arm, post-RP adjuvant Rx trials for prostate cancer, facilitating development of new therapeutic strategies.

Preparation and properties of polytetrafluoroethylene impregnated with rhenium oxides

NASA Technical Reports Server (NTRS)

Leibecki, H. F.; Easter, R. W.

1973-01-01

The results of tests carried out to determine the properties of polytetrafluorethylene (PTFE) impregnated with rhenium oxides are presented. The tests included measurement of physical properties of the impregnated material and investigation of the effects of preparation process variables. Based on the latter tests a mechanism to describe the permeation process is postulated which identifies the rate controlling step to be diffusion of ReF6 molecules into the solid during the initial ReF6 soak. Physical property tests indicated that the electronic conductance is increased by many orders of magnitude while the desirable properties of the PTFE remain virtually unchanged.

Creating Virtual-hand and Virtual-face Illusions to Investigate Self-representation

PubMed Central

Ma, Ke; Lippelt, Dominique P.; Hommel, Bernhard

2017-01-01

Studies investigating how people represent themselves and their own body often use variants of "ownership illusions", such as the traditional rubber-hand illusion or the more recently discovered enfacement illusion. However, these examples require rather artificial experimental setups, in which the artificial effector needs to be stroked in synchrony with the participants' real hand or face—a situation in which participants have no control over the stroking or the movements of their real or artificial effector. Here, we describe a technique to establish ownership illusions in a setup that is more realistic, more intuitive, and of presumably higher ecological validity. It allows creating the virtual-hand illusion by having participants control the movements of a virtual hand presented on a screen or in virtual space in front of them. If the virtual hand moves in synchrony with the participants' own real hand, they tend to perceive the virtual hand as part of their own body. The technique also creates the virtual-face illusion by having participants control the movements of a virtual face in front of them, again with the effect that they tend to perceive the face as their own if it moves in synchrony with their real face. Studying the circumstances that illusions of this sort can be created, increased, or reduced provides important information about how people create and maintain representations of themselves. PMID:28287602

Assessing subacute mild traumatic brain injury with a portable virtual reality balance device.

PubMed

Wright, W Geoffrey; McDevitt, Jane; Tierney, Ryan; Haran, F Jay; Appiah-Kubi, Kwadwo Osei; Dumont, Alex

2017-07-01

Balance impairment is a common sensorimotor symptom in mild traumatic brain injury (mTBI). We designed an affordable, portable virtual reality (VR)-based balance screening device (Virtual Environment TBI Screen [VETS]), which will be validated relative to the Neurocom Sensory Organization Test (SOT) to determine if it can replace commonly used postural assessments. This preliminary study examines healthy adults (n = 56) and adults with mTBI (n = 11). Participants performed six upright postural tasks on the VETS and the SOT. Analysis of variance was used to determine between-group differences. Pearson's correlations were used to establish construct validity. Known-groups approach was used to establish classification accuracy. The mTBI cohort performed significantly worse than the healthy cohort on the new device (p = 0.001). The new device has 91.0% accuracy and an ROC curve with a significant area-under-the-curve (AUC = 0.865, p < 0.001). Conditions with dynamic visual stimulation were the most sensitive to health status. The SOT had an 84.8% accuracy and AUC =0.703 (p = 0.034). The new VR-based device is a valid measure for detecting balance impairment following mTBI and can potentially replace more expensive and cumbersome equipment. Assessments that test visual-vestibular processing, such as VETS, increase sensitivity to mTBI-related balance deficits, which can be used to guide rehabilitation. Implications for rehabilitation Emerging technology using virtual reality can be economically integrated into the clinical setting for easy testing of postural control in neurologically impaired populations. Tailoring postural assessments to include tasks that rely on visual and vestibular integration will increase the accuracy of detecting balance impairment following mild traumatic brain injury.

Virtual Reality Training: "Cybersickness" and Effects on Sensorimotor Functions

NASA Technical Reports Server (NTRS)

Harm, Deborah L.; Taylor, Laura C.

2003-01-01

The overall goal of this study is to examine the extent to which exposure to virtual reality (VR) systems produces motion sickness and disrupts sensorimotor functions. Two of the major problems in using VRs are: 1) potential "cybersickness", a form of motion sickness, and 2) maladaptive sensorimotor coordination following virtual environment (VE) training. It is likely that users will eventually adapt to any unpleasant perceptual experiences in a virtual environment. However the most critical problem for training applications is that sensorimotor coordination strategies learned in the VE may not be similar to the responses required in the real environment. This study will evaluate and compare responses to the two types of VR delivery systems (head-mounted display [HMD] and a dome-projection system [DOME]), two exposure duration periods (30 minutes or 60 minutes), and repeated exposures (3 sessions). Specific responses that we will examine include cybersickness severity and symptom patterns, and several sensorimotor functions (eye-hea.d and eye-head-hand coordination, and postural equilibrium). To date, all hardware and software acquisition, development, integration and testing has been completed. A database has been developed and tested for the input, management and storage of all questionnaire data. All data analysis scripts have been developed and tested. Data was collected from 20 subjects in a pilot study that was conducted to determine the amount of training necessary to achieve a stable performance level. Seven subjects are currently enrolled in the study designed to examine the effects of exposure to VE systems on postural control. Data has been collected from two subjects, and it is expected that the results from ten subjects will be presented.

Validation of the Virtual MET as an assessment tool for executive functions.

PubMed

Rand, Debbie; Basha-Abu Rukan, Soraya; Weiss, Patrice L Tamar; Katz, Noomi

2009-08-01

The purpose of this study was to establish ecological validity and initial construct validity of a Virtual Multiple Errands Test (VMET) as an assessment tool for executive functions. It was implemented within the Virtual Mall (VMall), a novel functional video-capture virtual shopping environment. The main objectives were (1) to examine the relationships between the performance of three groups of participants in the Multiple Errands Test (MET) carried out in a real shopping mall and their performance in the VMET, (2) to assess the relationships between the MET and VMET of the post-stroke participant's level of executive functioning and independence in instrumental activities of daily living, and (3) to compare the performance of post-stroke participants to those of healthy young and older controls in both the MET and VMET. The study population included three groups; post-stroke participants (n = 9), healthy young participants (n = 20), and healthy older participants (n = 20). The VMET was able to differentiate between two age groups of healthy participants and between healthy and post-stroke participants thus demonstrating that it is sensitive to brain injury and ageing and supports construct validity between known groups. In addition, significant correlations were found between the MET and the VMET for both the post-stroke participants and older healthy participants. This provides initial support for the ecological validity of the VMET as an assessment tool of executive functions. However, further psychometric data on temporal stability are needed, namely test-retest reliability and responsiveness, before it is ready for clinical application. Further research using the VMET as an assessment tool within the VMall with larger groups and in additional populations is also recommended.

Peripersonal space as the space of the bodily self.

PubMed

Noel, Jean-Paul; Pfeiffer, Christian; Blanke, Olaf; Serino, Andrea

2015-11-01

Bodily self-consciousness (BSC) refers to experience of one's self as located within an owned body (self-identification) and as occupying a specific location in space (self-location). BSC can be altered through multisensory stimulation, as in the Full Body Illusion (FBI). If participants view a virtual body from a distance being stroked, while receiving synchronous tactile stroking on their physical body, they feel as if the virtual body were their own and they experience, subjectively, to drift toward the virtual body. Here we hypothesized that--while normally the experience of the body in space depends on the integration of multisensory body-related signals within a limited space surrounding the body (i.e. peripersonal space, PPS)--during the FBI the boundaries of PPS would shift toward the virtual body, that is, toward the position of experienced self-location. To test this hypothesis, we used synchronous visuo-tactile stroking to induce the FBI, as contrasted with a control condition of asynchronous stroking. Concurrently, we applied an audio-tactile interaction paradigm to estimate the boundaries of PPS. PPS was measured in front of and behind the participants' body as the distance where tactile information interacted with auditory stimuli looming in space toward the participant's physical body. We found that during synchronous stroking, i.e. when participants experienced the FBI, PPS boundaries extended in the front-space, toward the avatar, and concurrently shrunk in the back-space, as compared to the asynchronous stroking control condition, when FBI was induced. These findings support the view that during the FBI, PPS boundaries translate toward the virtual body, such that the PPS representation shifts from being centered at the location of the physical body to being now centered at the subjectively experienced location of the self. Copyright © 2015 Elsevier B.V. All rights reserved.

Peripersonal Space as the space of the Bodily Self

PubMed Central

Noel, Jean-Paul; Pfeiffer, Christian; Blanke, Olaf; Serino, Andrea

2016-01-01

Bodily self-consciousness (BSC) refers to experience of our self as located within an owned body (self-identification) and as occupying a specific location in space (self-location). BSC can be altered through multisensory stimulation, as in the Full Body Illusion (FBI). If participants view a virtual body from a distance being stroked, while receiving synchronous tactile stroking on their physical body, they feel such as the virtual body were their own and they experience, subjectively, to drift toward the virtual body. Here we hypothesized that - while normally the experience of the body in space depends on the integration of multisensory body-related signals within a limited space surrounding the body (i.e. peripersonal space, PPS) - during the FBI the boundaries of PPS would shift toward the virtual body, that is toward the position of self-location. To test this hypothesis, we used synchronous visuo-tactile stroking to induce the FBI, as contrasted with a control condition of asynchronous stroking. Concurrently, we applied an audio-tactile interaction paradigm to estimate the boundaries of PPS. PPS was measured in front of and behind the participants' body as the distance where tactile information interacted with auditory stimuli looming in space toward the participant's physical body. We found that during synchronous stroking, i.e. when participants experienced the FBI, PPS boundaries extended in the front-space, toward the avatar, and concurrently shrunk in the back-space, as compared to the asynchronous stroking control condition, where no FBI was induced. These findings support the view that during the FBI, PPS boundaries translate toward the virtual body, such that the PPS representation shifts from being centered at the location of the physical body to being now centered at the subjectively experienced location of the self. PMID:26231086

A novel semi-immersive virtual reality visuo-motor task activates ventrolateral prefrontal cortex: a functional near-infrared spectroscopy study

NASA Astrophysics Data System (ADS)

Basso Moro, Sara; Carrieri, Marika; Avola, Danilo; Brigadoi, Sabrina; Lancia, Stefania; Petracca, Andrea; Spezialetti, Matteo; Ferrari, Marco; Placidi, Giuseppe; Quaresima, Valentina

2016-06-01

Objective. In the last few years, the interest in applying virtual reality systems for neurorehabilitation is increasing. Their compatibility with neuroimaging techniques, such as functional near-infrared spectroscopy (fNIRS), allows for the investigation of brain reorganization with multimodal stimulation and real-time control of the changes occurring in brain activity. The present study was aimed at testing a novel semi-immersive visuo-motor task (VMT), which has the features of being adopted in the field of neurorehabilitation of the upper limb motor function. Approach. A virtual environment was simulated through a three-dimensional hand-sensing device (the LEAP Motion Controller), and the concomitant VMT-related prefrontal cortex (PFC) response was monitored non-invasively by fNIRS. Upon the VMT, performed at three different levels of difficulty, it was hypothesized that the PFC would be activated with an expected greater level of activation in the ventrolateral PFC (VLPFC), given its involvement in the motor action planning and in the allocation of the attentional resources to generate goals from current contexts. Twenty-one subjects were asked to move their right hand/forearm with the purpose of guiding a virtual sphere over a virtual path. A twenty-channel fNIRS system was employed for measuring changes in PFC oxygenated-deoxygenated hemoglobin (O2Hb/HHb, respectively). Main results. A VLPFC O2Hb increase and a concomitant HHb decrease were observed during the VMT performance, without any difference in relation to the task difficulty. Significance. The present study has revealed a particular involvement of the VLPFC in the execution of the novel proposed semi-immersive VMT adoptable in the neurorehabilitation field.

A novel semi-immersive virtual reality visuo-motor task activates ventrolateral prefrontal cortex: a functional near-infrared spectroscopy study.

PubMed

Moro, Sara Basso; Carrieri, Marika; Avola, Danilo; Brigadoi, Sabrina; Lancia, Stefania; Petracca, Andrea; Spezialetti, Matteo; Ferrari, Marco; Placidi, Giuseppe; Quaresima, Valentina

2016-06-01

In the last few years, the interest in applying virtual reality systems for neurorehabilitation is increasing. Their compatibility with neuroimaging techniques, such as functional near-infrared spectroscopy (fNIRS), allows for the investigation of brain reorganization with multimodal stimulation and real-time control of the changes occurring in brain activity. The present study was aimed at testing a novel semi-immersive visuo-motor task (VMT), which has the features of being adopted in the field of neurorehabilitation of the upper limb motor function. A virtual environment was simulated through a three-dimensional hand-sensing device (the LEAP Motion Controller), and the concomitant VMT-related prefrontal cortex (PFC) response was monitored non-invasively by fNIRS. Upon the VMT, performed at three different levels of difficulty, it was hypothesized that the PFC would be activated with an expected greater level of activation in the ventrolateral PFC (VLPFC), given its involvement in the motor action planning and in the allocation of the attentional resources to generate goals from current contexts. Twenty-one subjects were asked to move their right hand/forearm with the purpose of guiding a virtual sphere over a virtual path. A twenty-channel fNIRS system was employed for measuring changes in PFC oxygenated-deoxygenated hemoglobin (O2Hb/HHb, respectively). A VLPFC O2Hb increase and a concomitant HHb decrease were observed during the VMT performance, without any difference in relation to the task difficulty. The present study has revealed a particular involvement of the VLPFC in the execution of the novel proposed semi-immersive VMT adoptable in the neurorehabilitation field.

Virtual Sensors for Advanced Controllers in Rehabilitation Robotics.

PubMed

Mancisidor, Aitziber; Zubizarreta, Asier; Cabanes, Itziar; Portillo, Eva; Jung, Je Hyung

2018-03-05

In order to properly control rehabilitation robotic devices, the measurement of interaction force and motion between patient and robot is an essential part. Usually, however, this is a complex task that requires the use of accurate sensors which increase the cost and the complexity of the robotic device. In this work, we address the development of virtual sensors that can be used as an alternative of actual force and motion sensors for the Universal Haptic Pantograph (UHP) rehabilitation robot for upper limbs training. These virtual sensors estimate the force and motion at the contact point where the patient interacts with the robot using the mathematical model of the robotic device and measurement through low cost position sensors. To demonstrate the performance of the proposed virtual sensors, they have been implemented in an advanced position/force controller of the UHP rehabilitation robot and experimentally evaluated. The experimental results reveal that the controller based on the virtual sensors has similar performance to the one using direct measurement (less than 0.005 m and 1.5 N difference in mean error). Hence, the developed virtual sensors to estimate interaction force and motion can be adopted to replace actual precise but normally high-priced sensors which are fundamental components for advanced control of rehabilitation robotic devices.

Effective force control by muscle synergies.

PubMed

Berger, Denise J; d'Avella, Andrea

2014-01-01

Muscle synergies have been proposed as a way for the central nervous system (CNS) to simplify the generation of motor commands and they have been shown to explain a large fraction of the variation in the muscle patterns across a variety of conditions. However, whether human subjects are able to control forces and movements effectively with a small set of synergies has not been tested directly. Here we show that muscle synergies can be used to generate target forces in multiple directions with the same accuracy achieved using individual muscles. We recorded electromyographic (EMG) activity from 13 arm muscles and isometric hand forces during a force reaching task in a virtual environment. From these data we estimated the force associated to each muscle by linear regression and we identified muscle synergies by non-negative matrix factorization. We compared trajectories of a virtual mass displaced by the force estimated using the entire set of recorded EMGs to trajectories obtained using 4-5 muscle synergies. While trajectories were similar, when feedback was provided according to force estimated from recorded EMGs (EMG-control) on average trajectories generated with the synergies were less accurate. However, when feedback was provided according to recorded force (force-control) we did not find significant differences in initial angle error and endpoint error. We then tested whether synergies could be used as effectively as individual muscles to control cursor movement in the force reaching task by providing feedback according to force estimated from the projection of the recorded EMGs into synergy space (synergy-control). Human subjects were able to perform the task immediately after switching from force-control to EMG-control and synergy-control and we found no differences between initial movement direction errors and endpoint errors in all control modes. These results indicate that muscle synergies provide an effective strategy for motor coordination.

Development of a virtual speaking simulator using Image Based Rendering.

PubMed

Lee, J M; Kim, H; Oh, M J; Ku, J H; Jang, D P; Kim, I Y; Kim, S I

2002-01-01

The fear of speaking is often cited as the world's most common social phobia. The rapid growth of computer technology has enabled the use of virtual reality (VR) for the treatment of the fear of public speaking. There are two techniques for building virtual environments for the treatment of this fear: a model-based and a movie-based method. Both methods have the weakness that they are unrealistic and not controllable individually. To understand these disadvantages, this paper presents a virtual environment produced with Image Based Rendering (IBR) and a chroma-key simultaneously. IBR enables the creation of realistic virtual environments where the images are stitched panoramically with the photos taken from a digital camera. And the use of chroma-keys puts virtual audience members under individual control in the environment. In addition, real time capture technique is used in constructing the virtual environments enabling spoken interaction between the subject and a therapist or another subject.

Runtime Performance and Virtual Network Control Alternatives in VM-Based High-Fidelity Network Simulations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yoginath, Srikanth B; Perumalla, Kalyan S; Henz, Brian J

2012-01-01

In prior work (Yoginath and Perumalla, 2011; Yoginath, Perumalla and Henz, 2012), the motivation, challenges and issues were articulated in favor of virtual time ordering of Virtual Machines (VMs) in network simulations hosted on multi-core machines. Two major components in the overall virtualization challenge are (1) virtual timeline establishment and scheduling of VMs, and (2) virtualization of inter-VM communication. Here, we extend prior work by presenting scaling results for the first component, with experiment results on up to 128 VMs scheduled in virtual time order on a single 12-core host. We also explore the solution space of design alternatives formore » the second component, and present performance results from a multi-threaded, multi-queue implementation of inter-VM network control for synchronized execution with VM scheduling, incorporated in our NetWarp simulation system.« less

Modeling Environmental Impacts on Cognitive Performance for Artificially Intelligent Entities

DTIC Science & Technology

2017-06-01

of the agent behavior model is presented in a military-relevant virtual game environment. We then outline a quantitative approach to test the agent...relevant virtual game environment. We then outline a quantitative approach to test the agent behavior model within the virtual environment. Results show...x Game View of Hot Environment Condition Displaying Total “f” Cost for Each Searched Waypoint Node

Correlation of the Pediatric Volitional Questionnaire with the Test of Playfulness in a Virtual Environment: The Power of Engagement

ERIC Educational Resources Information Center

Reid, Denise

2005-01-01

The Pediatric Volitional Questionnaire (PVQ) was used along with the Test of Playfulness (TOP) to assess 16 children with cerebral palsy who took part in a study of virtual reality play intervention. Both observational measures are designed to assess children as they are engaged in occupations in one or more environments. Virtual reality offers an…

Software system design for the non-null digital Moiré interferometer

NASA Astrophysics Data System (ADS)

Chen, Meng; Hao, Qun; Hu, Yao; Wang, Shaopu; Li, Tengfei; Li, Lin

2016-11-01

Aspheric optical components are an indispensable part of modern optics systems. With the development of aspheric optical elements fabrication technique, high-precision figure error test method of aspheric surfaces is a quite urgent issue now. We proposed a digital Moiré interferometer technique (DMIT) based on partial compensation principle for aspheric and freeform surface measurement. Different from traditional interferometer, DMIT consists of a real and a virtual interferometer. The virtual interferometer is simulated with Zemax software to perform phase-shifting and alignment. We can get the results by a series of calculation with the real interferogram and virtual interferograms generated by computer. DMIT requires a specific, reliable software system to ensure its normal work. Image acquisition and data processing are two important parts in this system. And it is also a challenge to realize the connection between the real and virtual interferometer. In this paper, we present a software system design for DMIT with friendly user interface and robust data processing features, enabling us to acquire the figure error of the measured asphere. We choose Visual C++ as the software development platform and control the ideal interferometer by using hybrid programming with Zemax. After image acquisition and data transmission, the system calls image processing algorithms written with Matlab to calculate the figure error of the measured asphere. We test the software system experimentally. In the experiment, we realize the measurement of an aspheric surface and prove the feasibility of the software system.

Flexible, task-dependent use of sensory feedback to control hand movements

PubMed Central

Knill, David C.; Bondada, Amulya; Chhabra, Manu

2011-01-01

We tested whether changing accuracy demands for simple pointing movements leads humans to adjust the feedback control laws that map sensory signals from the moving hand to motor commands. Subjects made repeated pointing movements in a virtual environment to touch a button whose shape varied randomly from trial-to-trial – between squares, rectangles oriented perpendicular to the movement path and rectangles oriented parallel to the movement path. Subjects performed the task on a horizontal table, but saw the target configuration and a virtual rendering of their pointing finger through a mirror mounted between a monitor and the table. On a one-third of trials, the position of the virtual finger was perturbed by ±1 cm either in the movement direction or perpendicular to the movement direction when the finger passed behind an occluder. Subjects corrected quickly for the perturbations despite not consciously noticing them; however, they corrected almost twice as much for perturbations aligned with the narrow dimension of a target than for perturbations aligned with the long dimension. These changes in apparent feedback gain appeared in the kinematic trajectories soon after the time of the perturbations, indicating that they reflect differences in the feedback control law used throughout the duration of movements. The results indicate that the brain adjusts its feedback control law for individual movements “on-demand” to fit task demands. Simulations of optimal control laws for a two-joint arm show that accuracy demands alone, coupled with signal dependent noise lead to qualitatively the same behavior. PMID:21273407

Effects of the addition of transcranial direct current stimulation to virtual reality therapy after stroke: a pilot randomized controlled trial.

PubMed

Viana, R T; Laurentino, G E C; Souza, R J P; Fonseca, J B; Silva Filho, E M; Dias, S N; Teixeira-Salmela, L F; Monte-Silva, K K

2014-01-01

Upper limb (UL) impairment is the most common disabling deficit following a stroke. Previous studies have suggested that transcranial direct current stimulation (tDCS) enhances the effect of conventional therapies. This pilot double-blind randomized control trial aimed to determine whether or not tDCS, combined with Wii virtual reality therapy (VRT), would be superior to Wii therapy alone in improving upper limb function and quality of life in chronic stroke individuals. Twenty participants were randomly assigned either to an experimental group that received VRT and tDCS, or a control group that received VRT and sham tDCS. The therapy was delivered over 15 sessions with 13 minutes of active or sham anodal tDCS, and one hour of virtual reality therapy. The outcomes included were determined using the Fugl-Meyer scale, the Wolf motor function test, the modified Ashworth scale (MAS), grip strength, and the stroke specific quality of life scale (SSQOL). Minimal clinically important differences (MCID) were observed when assessing outcome data. Both groups demonstrated gains in all evaluated areas, except for the SSQOL-UL domain. Differences between groups were only observed in wrist spasticity levels in the experimental group, where more than 50% of the participants achieved the MCID. These findings support that tDCS, combined with VRT therapy, should be investigated and clarified further.

Virtual and flexible digital signal processing system based on software PnP and component works

NASA Astrophysics Data System (ADS)

He, Tao; Wu, Qinghua; Zhong, Fei; Li, Wei

2005-05-01

An idea about software PnP (Plug & Play) is put forward according to the hardware PnP. And base on this idea, a virtual flexible digital signal processing system (FVDSPS) is carried out. FVDSPS is composed of a main control center, many sub-function modules and other hardware I/O modules. Main control center sends out commands to sub-function modules, and manages running orders, parameters and results of sub-functions. The software kernel of FVDSPS is DSP (Digital Signal Processing) module, which communicates with the main control center through some protocols, accept commands or send requirements. The data sharing and exchanging between the main control center and the DSP modules are carried out and managed by the files system of the Windows Operation System through the effective communication. FVDSPS real orients objects, orients engineers and orients engineering problems. With FVDSPS, users can freely plug and play, and fast reconfigure a signal process system according to engineering problems without programming. What you see is what you get. Thus, an engineer can orient engineering problems directly, pay more attention to engineering problems, and promote the flexibility, reliability and veracity of testing system. Because FVDSPS orients TCP/IP protocol, through Internet, testing engineers, technology experts can be connected freely without space. Engineering problems can be resolved fast and effectively. FVDSPS can be used in many fields such as instruments and meter, fault diagnosis, device maintenance and quality control.

A Virtual Out-of-Body Experience Reduces Fear of Death

PubMed Central

2017-01-01

Immersive virtual reality can be used to visually substitute a person’s real body by a life-sized virtual body (VB) that is seen from first person perspective. Using real-time motion capture the VB can be programmed to move synchronously with the real body (visuomotor synchrony), and also virtual objects seen to strike the VB can be felt through corresponding vibrotactile stimulation on the actual body (visuotactile synchrony). This setup typically gives rise to a strong perceptual illusion of ownership over the VB. When the viewpoint is lifted up and out of the VB so that it is seen below this may result in an out-of-body experience (OBE). In a two-factor between-groups experiment with 16 female participants per group we tested how fear of death might be influenced by two different methods for producing an OBE. In an initial embodiment phase where both groups experienced the same multisensory stimuli there was a strong feeling of body ownership. Then the viewpoint was lifted up and behind the VB. In the experimental group once the viewpoint was out of the VB there was no further connection with it (no visuomotor or visuotactile synchrony). In a control condition, although the viewpoint was in the identical place as in the experimental group, visuomotor and visuotactile synchrony continued. While both groups reported high scores on a question about their OBE illusion, the experimental group had a greater feeling of disownership towards the VB below compared to the control group, in line with previous findings. Fear of death in the experimental group was found to be lower than in the control group. This is in line with previous reports that naturally occurring OBEs are often associated with enhanced belief in life after death. PMID:28068368

Optimization of armored fighting vehicle crew performance in a net-centric battlefield

NASA Astrophysics Data System (ADS)

McKeen, William P.; Espenant, Mark

2002-08-01

Traditional display, control and situational awareness technologies may not allow the fighting vehicle commander to take full advantage of the rich data environment made available in the net-centric battle field of the future. Indeed, the sheer complexity and volume of available data, if not properly managed, may actually reduce crew performance by overloading or confusing the commander with irrelevant information. New techniques must be explored to understand how to present battlefield information and provide the commander with continuous high quality situational awareness without significant cognitive overhead. Control of the vehicle's many complex systems must also be addressed the entire Soldier Machine Interface must be optimized if we are to realize the potential performance improvements. Defence Research and Development Canada (DRDC) and General Dynamics Canada Ltd. have embarked on a joint program called Future Armoured Fighting Vehicle Systems Technology Demonstrator, to explore these issues. The project is based on man-in-the-loop experimentation using virtual reality technology on a six degree-of-freedom motion platform that simulates the motion, sights and sounds inside a future armoured vehicle. The vehicle commander is provided with a virtual reality vision system to view a simulated 360 degree multi-spectrum representation of the battlespace, thus providing enhanced situational awareness. Graphic overlays with decision aid information will be added to reduce cognitive loading. Experiments will be conducted to evaluate the effectiveness of virtual control systems. The simulations are carried out in a virtual battlefield created by linking our simulation system with other simulation centers to provide a net-centric battlespace where enemy forces can be engaged in fire fights. Survivability and lethality will be measured in successive test sequences using real armoured fighting vehicle crews to optimize overall system effectiveness.

Adjunctive functional pharyngeal electrical stimulation reverses swallowing disability after brain lesions.

PubMed

Jayasekeran, Vanoo; Singh, Salil; Tyrrell, Pippa; Michou, Emilia; Jefferson, Samantha; Mistry, Satish; Gamble, Ed; Rothwell, John; Thompson, David; Hamdy, Shaheen

2010-05-01

Oropharyngeal dysphagia is an important disability that occurs after stroke; it contributes to aspiration pneumonia and death, and current modalities for rehabilitation of dysphagia have uncertain efficacy. We therefore examined the role of pharyngeal electrical stimulation (PES) in expediting human swallowing recovery after experimental (virtual) and actual (stroke) brain lesions. First, healthy subjects (n = 13) were given 1-Hz repetitive transcranial magnetic stimulation to induce a unilateral virtual lesion in pharyngeal motor cortex followed by active or sham (control) PES. Motor-evoked potentials and swallow accuracy were recorded before and after the lesion to assess PES response. Thereafter, 50 acute dysphagic stroke patients underwent either a dose-response study, to determine optimal parameters for PES (n = 22), or were assigned randomly to groups given either active or sham (control) PES (n = 28). The primary end point was the reduction of airway aspiration at 2 weeks postintervention. In contrast to sham PES, active PES reversed the cortical suppression induced by the virtual lesion (F(7,70) = 2.7; P = .015) and was associated with improvement in swallowing behavior (F(3,42) = 5; P = .02). After stroke, 1 PES treatment each day (U = 8.0; P = .043) for 3 days (U = 10.0) produced improved airway protection compared with controls (P = .038). Active PES also reduced aspiration (U = 54.0; P = .049), improved feeding status (U = 58.0; P = .040), and resulted in a shorter time to hospital discharge (Mantel-Cox log-rank test, P = 0.038). This pilot study of PES confirms that it is a safe neurostimulation intervention that reverses swallowing disability after virtual lesion or stroke. Copyright 2010 AGA Institute. Published by Elsevier Inc. All rights reserved.

White Paper for Virtual Control Room

NASA Technical Reports Server (NTRS)

Little, William; Tully-Hanson, Benjamin

2015-01-01

The Virtual Control Room (VCR) Proof of Concept (PoC) project is the result of an award given by the Fourth Annual NASA T&I Labs Challenge Project Call. This paper will outline the work done over the award period to build and enhance the capabilities of the Augmented/Virtual Reality (AVR) Lab at NASA's Kennedy Space Center (KSC) to create the VCR.

Can virtual nature improve patient experiences and memories of dental treatment? A study protocol for a randomized controlled trial.

PubMed

Tanja-Dijkstra, Karin; Pahl, Sabine; White, Mathew P; Andrade, Jackie; May, Jon; Stone, Robert J; Bruce, Malcolm; Mills, Ian; Auvray, Melissa; Gabe, Rhys; Moles, David R

2014-03-22

Dental anxiety and anxiety-related avoidance of dental care create significant problems for patients and the dental profession. Distraction interventions are used in daily medical practice to help patients cope with unpleasant procedures. There is evidence that exposure to natural scenery is beneficial for patients and that the use of virtual reality (VR) distraction is more effective than other distraction interventions, such as watching television. The main aim of this randomized controlled trial is to determine whether the use of VR during dental treatment can improve the overall dental experience and recollections of treatment for patients, breaking the negative cycle of memories of anxiety leading to further anxiety, and avoidance of future dental appointments. Additionally, the aim is to test whether VR benefits dental patients with all levels of dental anxiety or whether it could be especially beneficial for patients suffering from higher levels of dental anxiety. The third aim is to test whether the content of the VR distraction can make a difference for its effectiveness by comparing two types of virtual environments, a natural environment and an urban environment. The effectiveness of VR distraction will be examined in patients 18 years or older who are scheduled to undergo dental treatment for fillings and/or extractions, with a maximum length of 30 minutes. Patients will be randomly allocated into one of three groups. The first group will be exposed to a VR of a natural environment. The second group will be exposed to a VR of an urban environment. A third group consists of patients who receive standard care (control group). Primary outcomes relate to patients' memories of the dental treatment one week after treatment: (a) remembered pain, (b) intrusive thoughts and (c) vividness of memories. Other measures of interest are the dental experience, the treatment experience and the VR experience. Current Controlled Trials ISRCTN41442806.

Rapid prototyping 3D virtual world interfaces within a virtual factory environment

NASA Technical Reports Server (NTRS)

Kosta, Charles Paul; Krolak, Patrick D.

1993-01-01

On-going work into user requirements analysis using CLIPS (NASA/JSC) expert systems as an intelligent event simulator has led to research into three-dimensional (3D) interfaces. Previous work involved CLIPS and two-dimensional (2D) models. Integral to this work was the development of the University of Massachusetts Lowell parallel version of CLIPS, called PCLIPS. This allowed us to create both a Software Bus and a group problem-solving environment for expert systems development. By shifting the PCLIPS paradigm to use the VEOS messaging protocol we have merged VEOS (HlTL/Seattle) and CLIPS into a distributed virtual worlds prototyping environment (VCLIPS). VCLIPS uses the VEOS protocol layer to allow multiple experts to cooperate on a single problem. We have begun to look at the control of a virtual factory. In the virtual factory there are actors and objects as found in our Lincoln Logs Factory of the Future project. In this artificial reality architecture there are three VCLIPS entities in action. One entity is responsible for display and user events in the 3D virtual world. Another is responsible for either simulating the virtual factory or communicating with the real factory. The third is a user interface expert. The interface expert maps user input levels, within the current prototype, to control information for the factory. The interface to the virtual factory is based on a camera paradigm. The graphics subsystem generates camera views of the factory on standard X-Window displays. The camera allows for view control and object control. Control or the factory is accomplished by the user reaching into the camera views to perform object interactions. All communication between the separate CLIPS expert systems is done through VEOS.

Virtually Ostracized: Studying Ostracism in Immersive Virtual Environments

PubMed Central

Wesselmann, Eric D.; Law, Alvin Ty; Williams, Kipling D.

2012-01-01

Abstract Electronic-based communication (such as Immersive Virtual Environments; IVEs) may offer new ways of satisfying the need for social connection, but they also provide ways this need can be thwarted. Ostracism, being ignored and excluded, is a common social experience that threatens fundamental human needs (i.e., belonging, control, self-esteem, and meaningful existence). Previous ostracism research has made use of a variety of paradigms, including minimal electronic-based interactions (e.g., Cyberball) and communication (e.g., chatrooms and Short Message Services). These paradigms, however, lack the mundane realism that many IVEs now offer. Further, IVE paradigms designed to measure ostracism may allow researchers to test more nuanced hypotheses about the effects of ostracism. We created an IVE in which ostracism could be manipulated experimentally, emulating a previously validated minimal ostracism paradigm. We found that participants who were ostracized in this IVE experienced the same negative effects demonstrated in other ostracism paradigms, providing, to our knowledge, the first evidence of the negative effects of ostracism in virtual environments. Though further research directly exploring these effects in online virtual environments is needed, this research suggests that individuals encountering ostracism in other virtual environments (such as massively multiplayer online role playing games; MMORPGs) may experience negative effects similar to those of being ostracized in real life. This possibility may have serious implications for individuals who are marginalized in their real life and turn to IVEs to satisfy their need for social connection. PMID:22897472

Environmental Social Stress, Paranoia and Psychosis Liability: A Virtual Reality Study.

PubMed

Veling, Wim; Pot-Kolder, Roos; Counotte, Jacqueline; van Os, Jim; van der Gaag, Mark

2016-11-01

The impact of social environments on mental states is difficult to assess, limiting the understanding of which aspects of the social environment contribute to the onset of psychotic symptoms and how individual characteristics moderate this outcome. This study aimed to test sensitivity to environmental social stress as a mechanism of psychosis using Virtual Reality (VR) experiments. Fifty-five patients with recent onset psychotic disorder, 20 patients at ultra high risk for psychosis, 42 siblings of patients with psychosis, and 53 controls walked 5 times in a virtual bar with different levels of environmental social stress. Virtual social stressors were population density, ethnic density and hostility. Paranoia about virtual humans and subjective distress in response to virtual social stress exposures were measured with State Social Paranoia Scale (SSPS) and self-rated momentary subjective distress (SUD), respectively. Pre-existing (subclinical) symptoms were assessed with the Community Assessment of Psychic Experiences (CAPE), Green Paranoid Thoughts Scale (GPTS) and the Social Interaction Anxiety Scale (SIAS). Paranoia and subjective distress increased with degree of social stress in the environment. Psychosis liability and pre-existing symptoms, in particular negative affect, positively impacted the level of paranoia and distress in response to social stress. These results provide experimental evidence that heightened sensitivity to environmental social stress may play an important role in the onset and course of psychosis. © The Author 2016. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Testing virtual reality-based cue-exposure software: Which cue-elicited responses best discriminate between patients with eating disorders and healthy controls?

PubMed

Pla-Sanjuanelo, Joana; Ferrer-García, Marta; Vilalta-Abella, Ferran; Riva, Giuseppe; Dakanalis, Antonios; Ribas-Sabaté, Joan; Andreu-Gracia, Alexis; Fernandez-Aranda, Fernando; Sanchez-Diaz, Isabel; Escandón-Nagel, Neli; Gomez-Tricio, Osane; Tena, Virgínia; Gutiérrez-Maldonado, José

2017-07-27

Virtual reality (VR) technologies have been proposed as a new tool able to improve on in vivo exposure in patients with eating disorders. This study assessed the validity of a VR-based software for cue exposure therapy (CET) in people with bulimia nervosa (BN) and binge eating disorder (BED). Fifty eight outpatients (33 BN and 25 BED) and 135 healthy participants were exposed to 10 craved virtual foods and a neutral cue in four experimental virtual environments (kitchen, dining room, bedroom, and cafeteria). After exposure to each VR scenario, food craving and anxiety were assessed. The frequency/severity of episodes of uncontrollable overeating was also assessed and body mass index was measured prior to the exposure. In both groups, craving and anxiety responses when exposed to the food-related virtual environments were significantly higher than in the neutral-cue virtual environment. However, craving and anxiety levels were higher in the clinical group. Furthermore, cue-elicited anxiety was better at discriminating between clinical and healthy groups than cue-elicited craving. This study provides evidence of the ability of food-related VR environments to provoke food craving and anxiety responses in BN and BED patients and highlights the need to consider both responses during treatment. The results support the use of VR-CET in the treatment of eating disorder patients characterized by binge-eating and people with high bulimic symptoms.

Simulation-based training for thoracoscopic lobectomy: a randomized controlled trial: virtual-reality versus black-box simulation.

PubMed

Jensen, Katrine; Ringsted, Charlotte; Hansen, Henrik Jessen; Petersen, René Horsleben; Konge, Lars

2014-06-01

Video-assisted thoracic surgery is gradually replacing conventional open thoracotomy as the method of choice for the treatment of early-stage non-small cell lung cancers, and thoracic surgical trainees must learn and master this technique. Simulation-based training could help trainees overcome the first part of the learning curve, but no virtual-reality simulators for thoracoscopy are commercially available. This study aimed to investigate whether training on a laparoscopic simulator enables trainees to perform a thoracoscopic lobectomy. Twenty-eight surgical residents were randomized to either virtual-reality training on a nephrectomy module or traditional black-box simulator training. After a retention period they performed a thoracoscopic lobectomy on a porcine model and their performance was scored using a previously validated assessment tool. The groups did not differ in age or gender. All participants were able to complete the lobectomy. The performance of the black-box group was significantly faster during the test scenario than the virtual-reality group: 26.6 min (SD 6.7 min) versus 32.7 min (SD 7.5 min). No difference existed between the two groups when comparing bleeding and anatomical and non-anatomical errors. Simulation-based training and targeted instructions enabled the trainees to perform a simulated thoracoscopic lobectomy. Traditional black-box training was more effective than virtual-reality laparoscopy training. Thus, a dedicated simulator for thoracoscopy should be available before establishing systematic virtual-reality training programs for trainees in thoracic surgery.

Effects of physical randomness training on virtual and laboratory golf putting performance in novices.

PubMed

Pataky, T C; Lamb, P F

2018-06-01

External randomness exists in all sports but is perhaps most obvious in golf putting where robotic putters sink only 80% of 5 m putts due to unpredictable ball-green dynamics. The purpose of this study was to test whether physical randomness training can improve putting performance in novices. A virtual random-physics golf-putting game was developed based on controlled ball-roll data. Thirty-two subjects were assigned a unique randomness gain (RG) ranging from 0.1 to 2.0-times real-world randomness. Putter face kinematics were measured in 5 m laboratory putts before and after five days of virtual training. Performance was quantified using putt success rate and "miss-adjustment correlation" (MAC), the correlation between left-right miss magnitude and subsequent right-left kinematic adjustments. Results showed no RG-success correlation (r = -0.066, p = 0.719) but mildly stronger correlations with MAC for face angle (r = -0.168, p = 0.358) and clubhead path (r = -0.302, p = 0.093). The strongest RG-MAC correlation was observed during virtual training (r = -0.692, p < 0.001). These results suggest that subjects quickly adapt to physical randomness in virtual training, and also that this learning may weakly transfer to real golf putting kinematics. Adaptation to external physical randomness during virtual training may therefore help golfers adapt to external randomness in real-world environments.

Virtually ostracized: studying ostracism in immersive virtual environments.

PubMed

Kassner, Matthew P; Wesselmann, Eric D; Law, Alvin Ty; Williams, Kipling D

2012-08-01

Electronic-based communication (such as Immersive Virtual Environments; IVEs) may offer new ways of satisfying the need for social connection, but they also provide ways this need can be thwarted. Ostracism, being ignored and excluded, is a common social experience that threatens fundamental human needs (i.e., belonging, control, self-esteem, and meaningful existence). Previous ostracism research has made use of a variety of paradigms, including minimal electronic-based interactions (e.g., Cyberball) and communication (e.g., chatrooms and Short Message Services). These paradigms, however, lack the mundane realism that many IVEs now offer. Further, IVE paradigms designed to measure ostracism may allow researchers to test more nuanced hypotheses about the effects of ostracism. We created an IVE in which ostracism could be manipulated experimentally, emulating a previously validated minimal ostracism paradigm. We found that participants who were ostracized in this IVE experienced the same negative effects demonstrated in other ostracism paradigms, providing, to our knowledge, the first evidence of the negative effects of ostracism in virtual environments. Though further research directly exploring these effects in online virtual environments is needed, this research suggests that individuals encountering ostracism in other virtual environments (such as massively multiplayer online role playing games; MMORPGs) may experience negative effects similar to those of being ostracized in real life. This possibility may have serious implications for individuals who are marginalized in their real life and turn to IVEs to satisfy their need for social connection.

Relationship between perceived competence and performance during real and virtual motor tasks by children with developmental coordination disorder.

PubMed

Engel-Yeger, Batya; Sido, Rotem; Mimouni-Bloch, Aviva; Weiss, Patrice L

2017-10-01

(i) To compare children with DCD and typically developing participants via standard motor assessments, two interactive virtual games, measures of physical, social and cognitive self-competence and feedback while playing the virtual games and (ii) To examine the contribution of age and each motor assessment to predict self-competence. Participants were 25 boys with DCD and 25 typically developing boys, aged 5-9 years. They completed the M-ABC-2, the Pictorial Scale of Perceived Competence, the 6-Minute Walk Test, and then played the two Kinect games and completed the Short Feedback Questionnaire for Children. Children with DCD showed lower physical competence and lower performance than the typical controls in all standard motor assessments. This performance significantly correlated with the children achievements in part of virtual games and with their self-perceived experience while performing within virtual environments. Among the DCD group, Kinect Running game significantly predicted physical and social competence. The significant correlations between the virtual games and standard motor assessments support the feasibility of using these games when evaluating children with DCD for the richer profile they provide. Implications for rehabilitation Clinicians should refer to the impacts of DCD on child's self-competence and daily life. Technological rehabilitation and the use of VR games have the potential to improve self-competence of children with DCD. By including VR games that simulate real life in the intervention for DCD, clinicians may raise child's enjoyment, self-competence and involvement in therapy.

Benchmarking Distance Control and Virtual Drilling for Lateral Skull Base Surgery.

PubMed

Voormolen, Eduard H J; Diederen, Sander; van Stralen, Marijn; Woerdeman, Peter A; Noordmans, Herke Jan; Viergever, Max A; Regli, Luca; Robe, Pierre A; Berkelbach van der Sprenkel, Jan Willem

2018-01-01

Novel audiovisual feedback methods were developed to improve image guidance during skull base surgery by providing audiovisual warnings when the drill tip enters a protective perimeter set at a distance around anatomic structures ("distance control") and visualizing bone drilling ("virtual drilling"). To benchmark the drill damage risk reduction provided by distance control, to quantify the accuracy of virtual drilling, and to investigate whether the proposed feedback methods are clinically feasible. In a simulated surgical scenario using human cadavers, 12 unexperienced users (medical students) drilled 12 mastoidectomies. Users were divided into a control group using standard image guidance and 3 groups using distance control with protective perimeters of 1, 2, or 3 mm. Damage to critical structures (sigmoid sinus, semicircular canals, facial nerve) was assessed. Neurosurgeons performed another 6 mastoidectomy/trans-labyrinthine and retro-labyrinthine approaches. Virtual errors as compared with real postoperative drill cavities were calculated. In a clinical setting, 3 patients received lateral skull base surgery with the proposed feedback methods. Users drilling with distance control protective perimeters of 3 mm did not damage structures, whereas the groups using smaller protective perimeters and the control group injured structures. Virtual drilling maximum cavity underestimations and overestimations were 2.8 ± 0.1 and 3.3 ± 0.4 mm, respectively. Feedback methods functioned properly in the clinical setting. Distance control reduced the risks of drill damage proportional to the protective perimeter distance. Errors in virtual drilling reflect spatial errors of the image guidance system. These feedback methods are clinically feasible. Copyright © 2017 Elsevier Inc. All rights reserved.

Effectiveness of conventional versus virtual reality-based balance exercises in vestibular rehabilitation for unilateral peripheral vestibular loss: results of a randomized controlled trial.

PubMed

Meldrum, Dara; Herdman, Susan; Vance, Roisin; Murray, Deirdre; Malone, Kareena; Duffy, Douglas; Glennon, Aine; McConn-Walsh, Rory

2015-07-01

To compare the effectiveness of virtual reality-based balance exercises to conventional balance exercises during vestibular rehabilitation in patients with unilateral peripheral vestibular loss (UVL). Assessor-blind, randomized controlled trial. Two acute care university teaching hospitals. Patients with UVL (N=71) who had dizziness/vertigo, and gait and balance impairment. Patients with UVL were randomly assigned to receive 6 weeks of either conventional (n=36) or virtual reality-based (n=35) balance exercises during vestibular rehabilitation. The virtual reality-based group received an off-the-shelf virtual reality gaming system for home exercise, and the conventional group received a foam balance mat. Treatment comprised weekly visits to a physiotherapist and a daily home exercise program. The primary outcome was self-preferred gait speed. Secondary outcomes included other gait parameters and tasks, Sensory Organization Test (SOT), dynamic visual acuity, Hospital Anxiety and Depression Scale, Vestibular Rehabilitation Benefits Questionnaire, and Activities Balance Confidence Questionnaire. The subjective experience of vestibular rehabilitation was measured with a questionnaire. Both groups improved, but there were no significant differences in gait speed between the groups postintervention (mean difference, -.03m/s; 95% confidence interval [CI], -.09 to .02m/s). There were also no significant differences between the groups in SOT scores (mean difference, .82%; 95% CI, -5.00% to 6.63%) or on any of the other secondary outcomes (P>.05). In both groups, adherence to exercise was high (∼77%), but the virtual reality-based group reported significantly more enjoyment (P=.001), less difficulty with (P=.009) and less tiredness after (P=.03) balance exercises. At 6 months, there were no significant between-group differences in physical outcomes. Virtual reality-based balance exercises performed during vestibular rehabilitation were not superior to conventional balance exercises during vestibular rehabilitation but may provide a more enjoyable method of retraining balance after unilateral peripheral vestibular loss. Copyright © 2015 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Objective Assessment of Activity Limitation in Glaucoma with Smartphone Virtual Reality Goggles: A Pilot Study.

PubMed

Goh, Rachel L Z; Kong, Yu Xiang George; McAlinden, Colm; Liu, John; Crowston, Jonathan G; Skalicky, Simon E

2018-01-01

To evaluate the use of smartphone-based virtual reality to objectively assess activity limitation in glaucoma. Cross-sectional study of 93 patients (54 mild, 22 moderate, 17 severe glaucoma). Sociodemographics, visual parameters, Glaucoma Activity Limitation-9 and Visual Function Questionnaire - Utility Index (VFQ-UI) were collected. Mean age was 67.4 ± 13.2 years; 52.7% were male; 65.6% were driving. A smartphone placed inside virtual reality goggles was used to administer the Virtual Reality Glaucoma Visual Function Test (VR-GVFT) to participants, consisting of three parts: stationary, moving ball, driving. Rasch analysis and classical validity tests were conducted to assess performance of VR-GVFT. Twenty-four of 28 stationary test items showed acceptable fit to the Rasch model (person separation 3.02, targeting 0). Eleven of 12 moving ball test items showed acceptable fit (person separation 3.05, targeting 0). No driving test items showed acceptable fit. Stationary test person scores showed good criterion validity, differentiating between glaucoma severity groups ( P = 0.014); modest convergence validity, with mild to moderate correlation with VFQ-UI, better eye (BE) mean deviation, BE pattern deviation, BE central scotoma, worse eye (WE) visual acuity, and contrast sensitivity (CS) in both eyes ( R = 0.243-0.381); and suboptimal divergent validity. Multivariate analysis showed that lower WE CS ( P = 0.044) and greater age ( P = 0.009) were associated with worse stationary test person scores. Smartphone-based virtual reality may be a portable objective simulation test of activity limitation related to glaucomatous visual loss. The use of simulated virtual environments could help better understand the activity limitations that affect patients with glaucoma.

Objective Assessment of Activity Limitation in Glaucoma with Smartphone Virtual Reality Goggles: A Pilot Study

PubMed Central

Goh, Rachel L. Z.; McAlinden, Colm; Liu, John; Crowston, Jonathan G.; Skalicky, Simon E.

2018-01-01

Purpose To evaluate the use of smartphone-based virtual reality to objectively assess activity limitation in glaucoma. Methods Cross-sectional study of 93 patients (54 mild, 22 moderate, 17 severe glaucoma). Sociodemographics, visual parameters, Glaucoma Activity Limitation-9 and Visual Function Questionnaire – Utility Index (VFQ-UI) were collected. Mean age was 67.4 ± 13.2 years; 52.7% were male; 65.6% were driving. A smartphone placed inside virtual reality goggles was used to administer the Virtual Reality Glaucoma Visual Function Test (VR-GVFT) to participants, consisting of three parts: stationary, moving ball, driving. Rasch analysis and classical validity tests were conducted to assess performance of VR-GVFT. Results Twenty-four of 28 stationary test items showed acceptable fit to the Rasch model (person separation 3.02, targeting 0). Eleven of 12 moving ball test items showed acceptable fit (person separation 3.05, targeting 0). No driving test items showed acceptable fit. Stationary test person scores showed good criterion validity, differentiating between glaucoma severity groups (P = 0.014); modest convergence validity, with mild to moderate correlation with VFQ-UI, better eye (BE) mean deviation, BE pattern deviation, BE central scotoma, worse eye (WE) visual acuity, and contrast sensitivity (CS) in both eyes (R = 0.243–0.381); and suboptimal divergent validity. Multivariate analysis showed that lower WE CS (P = 0.044) and greater age (P = 0.009) were associated with worse stationary test person scores. Conclusions Smartphone-based virtual reality may be a portable objective simulation test of activity limitation related to glaucomatous visual loss. Translational Relevance The use of simulated virtual environments could help better understand the activity limitations that affect patients with glaucoma. PMID:29372112

Human agency beliefs influence behaviour during virtual social interactions.

PubMed

Caruana, Nathan; Spirou, Dean; Brock, Jon

2017-01-01

In recent years, with the emergence of relatively inexpensive and accessible virtual reality technologies, it is now possible to deliver compelling and realistic simulations of human-to-human interaction. Neuroimaging studies have shown that, when participants believe they are interacting via a virtual interface with another human agent, they show different patterns of brain activity compared to when they know that their virtual partner is computer-controlled. The suggestion is that users adopt an "intentional stance" by attributing mental states to their virtual partner. However, it remains unclear how beliefs in the agency of a virtual partner influence participants' behaviour and subjective experience of the interaction. We investigated this issue in the context of a cooperative "joint attention" game in which participants interacted via an eye tracker with a virtual onscreen partner, directing each other's eye gaze to different screen locations. Half of the participants were correctly informed that their partner was controlled by a computer algorithm ("Computer" condition). The other half were misled into believing that the virtual character was controlled by a second participant in another room ("Human" condition). Those in the "Human" condition were slower to make eye contact with their partner and more likely to try and guide their partner before they had established mutual eye contact than participants in the "Computer" condition. They also responded more rapidly when their partner was guiding them, although the same effect was also found for a control condition in which they responded to an arrow cue. Results confirm the influence of human agency beliefs on behaviour in this virtual social interaction context. They further suggest that researchers and developers attempting to simulate social interactions should consider the impact of agency beliefs on user experience in other social contexts, and their effect on the achievement of the application's goals.

Three dimensional tracking with misalignment between display and control axes

NASA Technical Reports Server (NTRS)

Ellis, Stephen R.; Tyler, Mitchell; Kim, Won S.; Stark, Lawrence

1992-01-01

Human operators confronted with misaligned display and control frames of reference performed three dimensional, pursuit tracking in virtual environment and virtual space simulations. Analysis of the components of the tracking errors in the perspective displays presenting virtual space showed that components of the error due to visual motor misalignment may be linearly separated from those associated with the mismatch between display and control coordinate systems. Tracking performance improved with several hours practice despite previous reports that such improvement did not take place.

Virtual reality for intelligent and interactive operating, training, and visualization systems

NASA Astrophysics Data System (ADS)

Freund, Eckhard; Rossmann, Juergen; Schluse, Michael

2000-10-01

Virtual Reality Methods allow a new and intuitive way of communication between man and machine. The basic idea of Virtual Reality (VR) is the generation of artificial computer simulated worlds, which the user not only can look at but also can interact with actively using data glove and data helmet. The main emphasis for the use of such techniques at the IRF is the development of a new generation of operator interfaces for the control of robots and other automation components and for intelligent training systems for complex tasks. The basic idea of the methods developed at the IRF for the realization of Projective Virtual Reality is to let the user work in the virtual world as he would act in reality. The user actions are recognized by the Virtual reality System and by means of new and intelligent control software projected onto the automation components like robots which afterwards perform the necessary actions in reality to execute the users task. In this operation mode the user no longer has to be a robot expert to generate tasks for robots or to program them, because intelligent control software recognizes the users intention and generated automatically the commands for nearly every automation component. Now, Virtual Reality Methods are ideally suited for universal man-machine-interfaces for the control and supervision of a big class of automation components, interactive training and visualization systems. The Virtual Reality System of the IRF-COSIMIR/VR- forms the basis for different projects starting with the control of space automation systems in the projects CIROS, VITAL and GETEX, the realization of a comprehensive development tool for the International Space Station and last but not least with the realistic simulation fire extinguishing, forest machines and excavators which will be presented in the final paper in addition to the key ideas of this Virtual Reality System.

Stochastic targeted (STAR) glycemic control: design, safety, and performance.

PubMed

Evans, Alicia; Le Compte, Aaron; Tan, Chia-Siong; Ward, Logan; Steel, James; Pretty, Christopher G; Penning, Sophie; Suhaimi, Fatanah; Shaw, Geoffrey M; Desaive, Thomas; Chase, J Geoffrey

2012-01-01

Tight glycemic control (TGC) has shown benefits but has been difficult to achieve consistently. STAR (Stochastic TARgeted) is a flexible, model-based TGC approach that directly accounts for intra- and interpatient variability with a stochastically derived maximum 5% risk of blood glucose (BG) below 72 mg/dl. This research assesses the safety, efficacy, and clinical burden of a STAR TGC controller modulating both insulin and nutrition inputs in virtual and clinical pilot trials. Clinically validated virtual trials using data from 370 patients in the SPRINT (Specialized Relative Insulin and Nutrition Titration) study were used to design the STAR protocol and test its safety, performance, and required clinical effort prior to clinical pilot trials. Insulin and nutrition interventions were given every 1-3 h as chosen by the nurse to allow them to manage workload. Interventions were designed to maximize the overlap of the model-predicted (5-95(th) percentile) range of BG outcomes with the 72-117 mg/dl band and thus provide a maximum 5% risk of BG <72 mg/dl. Interventions were calculated using clinically validated computer models of human metabolism and its variability in critical illness. Carbohydrate intake (all sources) was selected to maximize intake up to 100% of the American College of Chest Physicians/Society of Critical Care Medicine (ACCP/SCCM) goal (25 kg/kcal/h). Insulin doses were limited (8 U/h maximum), with limited increases based on current rate (0.5-2.0 U/h). Initial clinical pilot trials involved 3 patients covering ~450 h. Approval was granted by the Upper South A Regional Ethics Committee. Virtual trials indicate that STAR provides similar glycemic control performance to SPRINT with 2-3 h (maximum) measurement intervals. Time in the 72-126 mg/dl and 72-145 mg/dl bands was equivalent for all controllers, indicating that glycemic outcome differences between protocols were only shifted in this range. Safety from hypoglycemia was improved. Importantly, STAR using 2-3 h (maximum) intervention intervals reduced clinical burden up to 30%, which is clinically very significant. Initial clinical trials showed glycemic performance, safety, and management of inter- and intrapatient variability that matched or exceeded the virtual trial results. In virtual trials, STAR TGC provided tight control that maximized the likelihood of BG in a clinically specified glycemic band and reduced hypoglycemia with a maximum 5% (or lower) expected risk of light hypoglycemia (BG <72 mg/dl) via model-based management of intra- and interpatient variability. Clinical workload was self-managed and reduced up to 30% compared with SPRINT. Initial pilot clinical trials matched or exceeded these virtual results. © 2012 Diabetes Technology Society.

Effects of virtual reality training on functional reaching movements in people with Parkinson's disease: a randomized controlled pilot trial.

PubMed

Ma, Hui-Ing; Hwang, Wen-Juh; Fang, Jing-Jing; Kuo, Jui-Kun; Wang, Ching-Yi; Leong, Iat-Fai; Wang, Tsui-Ying

2011-10-01

To investigate whether practising reaching for virtual moving targets would improve motor performance in people with Parkinson's disease. Randomized pretest-posttest control group design. A virtual reality laboratory in a university setting. Thirty-three adults with Parkinson's disease. The virtual reality training required 60 trials of reaching for fast-moving virtual balls with the dominant hand. The control group had 60 practice trials turning pegs with their non-dominant hand. Pretest and posttest required reaching with the dominant hand to grasp real stationary balls and balls moving at different speeds down a ramp. Success rates and kinematic data (movement time, peak velocity and percentage of movement time for acceleration phase) from pretest and posttest were recorded to determine the immediate transfer effects. Compared with the control group, the virtual reality training group became faster (F = 9.08, P = 0.005) and more forceful (F = 9.36, P = 0.005) when reaching for real stationary balls. However, there was no significant difference in success rate or movement kinematics between the two groups when reaching for real moving balls. A short virtual reality training programme improved the movement speed of discrete aiming tasks when participants reached for real stationary objects. However, the transfer effect was minimal when reaching for real moving objects.

Determining the optimal window length for pattern recognition-based myoelectric control: balancing the competing effects of classification error and controller delay.

PubMed

Smith, Lauren H; Hargrove, Levi J; Lock, Blair A; Kuiken, Todd A

2011-04-01

Pattern recognition-based control of myoelectric prostheses has shown great promise in research environments, but has not been optimized for use in a clinical setting. To explore the relationship between classification error, controller delay, and real-time controllability, 13 able-bodied subjects were trained to operate a virtual upper-limb prosthesis using pattern recognition of electromyogram (EMG) signals. Classification error and controller delay were varied by training different classifiers with a variety of analysis window lengths ranging from 50 to 550 ms and either two or four EMG input channels. Offline analysis showed that classification error decreased with longer window lengths (p < 0.01 ). Real-time controllability was evaluated with the target achievement control (TAC) test, which prompted users to maneuver the virtual prosthesis into various target postures. The results indicated that user performance improved with lower classification error (p < 0.01 ) and was reduced with longer controller delay (p < 0.01 ), as determined by the window length. Therefore, both of these effects should be considered when choosing a window length; it may be beneficial to increase the window length if this results in a reduced classification error, despite the corresponding increase in controller delay. For the system employed in this study, the optimal window length was found to be between 150 and 250 ms, which is within acceptable controller delays for conventional multistate amplitude controllers.

Experimental Validation of Motor Primitive-Based Control for Leg Exoskeletons during Continuous Multi-Locomotion Tasks

PubMed Central

Ruiz Garate, Virginia; Parri, Andrea; Yan, Tingfang; Munih, Marko; Molino Lova, Raffaele; Vitiello, Nicola; Ronsse, Renaud

2017-01-01

An emerging approach to design locomotion assistive devices deals with reproducing desirable biological principles of human locomotion. In this paper, we present a bio-inspired controller for locomotion assistive devices based on the concept of motor primitives. The weighted combination of artificial primitives results in a set of virtual muscle stimulations. These stimulations then activate a virtual musculoskeletal model producing reference assistive torque profiles for different locomotion tasks (i.e., walking, ascending stairs, and descending stairs). The paper reports the validation of the controller through a set of experiments conducted with healthy participants. The proposed controller was tested for the first time with a unilateral leg exoskeleton assisting hip, knee, and ankle joints by delivering a fraction of the computed reference torques. Importantly, subjects performed a track involving ground-level walking, ascending stairs, and descending stairs and several transitions between these tasks. These experiments highlighted the capability of the controller to provide relevant assistive torques and to effectively handle transitions between the tasks. Subjects displayed a natural interaction with the device. Moreover, they significantly decreased the time needed to complete the track when the assistance was provided, as compared to wearing the device with no assistance. PMID:28367121

Effects of enactment in episodic memory: a pilot virtual reality study with young and elderly adults.

PubMed

Jebara, Najate; Orriols, Eric; Zaoui, Mohamed; Berthoz, Alain; Piolino, Pascale

2014-01-01

None of the previous studies on aging have tested the influence of action with respect to the degree of interaction with the environment (active or passive navigation) and the source of itinerary choice (self or externally imposed), on episodic memory (EM) encoding. The aim of this pilot study was to explore the influence of these factors on feature binding (the association between what, where, and when) in EM and on the subjective sense of remembering. Navigation in a virtual city was performed by 64 young and 64 older adults in one of four modes of exploration: (1) passive condition where participants were immersed as passengers of a virtual car [no interaction, no itinerary control (IC)], (2) IC (the subject chose the itinerary, but did not drive the car), (3) low, or (4) high navigation control (the subject just moved the car on rails or drove the car with a steering-wheel and a gas pedal on a fixed itinerary, respectively). The task was to memorize as many events encountered in the virtual environment as possible along with their factual (what), spatial (where), and temporal (when) details, and then to perform immediate and delayed memory tests. An age-related decline was evidenced for immediate and delayed feature binding. Compared to passive and high navigation conditions, and regardless of age-groups, feature binding was enhanced by low navigation and IC conditions. The subjective sense of remembering was boosted by the IC in older adults. Memory performance following high navigation was specifically linked to variability in executive functions. The present findings suggest that the decision of the itinerary is beneficial to boost EM in aging, although it does not eliminate age-related deficits. Active navigation can also enhance EM when it is not too demanding for subjects' cognitive resources.

Effects of Enactment in Episodic Memory: A Pilot Virtual Reality Study with Young and Elderly Adults

PubMed Central

Jebara, Najate; Orriols, Eric; Zaoui, Mohamed; Berthoz, Alain; Piolino, Pascale

2014-01-01

None of the previous studies on aging have tested the influence of action with respect to the degree of interaction with the environment (active or passive navigation) and the source of itinerary choice (self or externally imposed), on episodic memory (EM) encoding. The aim of this pilot study was to explore the influence of these factors on feature binding (the association between what, where, and when) in EM and on the subjective sense of remembering. Navigation in a virtual city was performed by 64 young and 64 older adults in one of four modes of exploration: (1) passive condition where participants were immersed as passengers of a virtual car [no interaction, no itinerary control (IC)], (2) IC (the subject chose the itinerary, but did not drive the car), (3) low, or (4) high navigation control (the subject just moved the car on rails or drove the car with a steering-wheel and a gas pedal on a fixed itinerary, respectively). The task was to memorize as many events encountered in the virtual environment as possible along with their factual (what), spatial (where), and temporal (when) details, and then to perform immediate and delayed memory tests. An age-related decline was evidenced for immediate and delayed feature binding. Compared to passive and high navigation conditions, and regardless of age-groups, feature binding was enhanced by low navigation and IC conditions. The subjective sense of remembering was boosted by the IC in older adults. Memory performance following high navigation was specifically linked to variability in executive functions. The present findings suggest that the decision of the itinerary is beneficial to boost EM in aging, although it does not eliminate age-related deficits. Active navigation can also enhance EM when it is not too demanding for subjects’ cognitive resources. PMID:25566069

AVESTAR Center for Operational Excellence of Electricity Generation Plants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zitney, Stephen

2012-08-29

To address industry challenges in attaining operational excellence for electricity generation plants, the U.S. Department of Energy’s (DOE) National Energy Technology Laboratory (NETL) has launched a world-class facility for Advanced Virtual Energy Simulation Training and Research (AVESTARTM). This presentation will highlight the AVESTARTM Center simulators, facilities, and comprehensive training, education, and research programs focused on the operation and control of high-efficiency, near-zero-emission electricity generation plants. The AVESTAR Center brings together state-of-the-art, real-time, high-fidelity dynamic simulators with full-scope operator training systems (OTSs) and 3D virtual immersive training systems (ITSs) into an integrated energy plant and control room environment. AVESTAR’s initial offeringmore » combines--for the first time--a “gasification with CO2 capture” process simulator with a “combined-cycle” power simulator together in a single OTS/ITS solution for an integrated gasification combined cycle (IGCC) power plant with carbon dioxide (CO2) capture. IGCC systems are an attractive technology option for power generation, especially when capturing and storing CO2 is necessary to satisfy emission targets. The AVESTAR training program offers a variety of courses that merge classroom learning, simulator-based OTS learning in a control-room operations environment, and immersive learning in the interactive 3D virtual plant environment or ITS. All of the courses introduce trainees to base-load plant operation, control, startups, and shutdowns. Advanced courses require participants to become familiar with coordinated control, fuel switching, power-demand load shedding, and load following, as well as to problem solve equipment and process malfunctions. Designed to ensure work force development, training is offered for control room and plant field operators, as well as engineers and managers. Such comprehensive simulator-based instruction allows for realistic training without compromising worker, equipment, and environmental safety. It also better prepares operators and engineers to manage the plant closer to economic constraints while minimizing or avoiding the impact of any potentially harmful, wasteful, or inefficient events. The AVESTAR Center is also used to augment graduate and undergraduate engineering education in the areas of process simulation, dynamics, control, and safety. Students and researchers gain hands-on simulator-based training experience and learn how the commercial-scale power plants respond dynamically to changes in manipulated inputs, such as coal feed flow rate and power demand. Students also analyze how the regulatory control system impacts power plant performance and stability. In addition, students practice start-up, shutdown, and malfunction scenarios. The 3D virtual ITSs are used for plant familiarization, walk-through, equipment animations, and safety scenarios. To further leverage the AVESTAR facilities and simulators, NETL and its university partners are pursuing an innovative and collaborative R&D program. In the area of process control, AVESTAR researchers are developing enhanced strategies for regulatory control and coordinated plant-wide control, including gasifier and gas turbine lead, as well as advanced process control using model predictive control (MPC) techniques. Other AVESTAR R&D focus areas include high-fidelity equipment modeling using partial differential equations, dynamic reduced order modeling, optimal sensor placement, 3D virtual plant simulation, and modern grid. NETL and its partners plan to continue building the AVESTAR portfolio of dynamic simulators, immersive training systems, and advanced research capabilities to satisfy industry’s growing need for training and experience with the operation and control of clean energy plants. Future dynamic simulators under development include natural gas combined cycle (NGCC) and supercritical pulverized coal (SCPC) plants with post-combustion CO2 capture. These dynamic simulators are targeted for use in establishing a Virtual Carbon Capture Center (VCCC), similar in concept to the DOE’s National Carbon Capture Center for slipstream testing. The VCCC will enable developers of CO2 capture technologies to integrate, test, and optimize the operation of their dynamic capture models within the context of baseline power plant dynamic models. The objective is to provide hands-on, simulator-based “learn-by-operating” test platforms to accelerate the scale-up and deployment of CO2 capture technologies. Future AVESTAR plans also include pursuing R&D on the dynamics, operation, and control of integrated electricity generation and storage systems for the modern grid era. Special emphasis will be given to combining load-following energy plants with renewable and distributed generating supplies and fast-ramping energy storage systems to provide near constant baseload power.« less

A Proposed Framework for Collaborative Design in a Virtual Environment

NASA Astrophysics Data System (ADS)

Breland, Jason S.; Shiratuddin, Mohd Fairuz

This paper describes a proposed framework for a collaborative design in a virtual environment. The framework consists of components that support a true collaborative design in a real-time 3D virtual environment. In support of the proposed framework, a prototype application is being developed. The authors envision the framework will have, but not limited to the following features: (1) real-time manipulation of 3D objects across the network, (2) support for multi-designer activities and information access, (3) co-existence within same virtual space, etc. This paper also discusses a proposed testing to determine the possible benefits of a collaborative design in a virtual environment over other forms of collaboration, and results from a pilot test.

A Second Chance at Health: How a 3D Virtual World Can Improve Health Self-Efficacy for Weight Loss Management Among Adults.

PubMed

Behm-Morawitz, Elizabeth; Lewallen, Jennifer; Choi, Grace

2016-02-01

Health self-efficacy, or the beliefs in one's capabilities to perform health behaviors, is a significant factor in eliciting health behavior change, such as weight loss. Research has demonstrated that virtual embodiment has the potential to alter one's psychology and physicality, particularly in health contexts; however, little is known about the impacts embodiment in a virtual world has on health self-efficacy. The present research is a randomized controlled trial (N = 90) examining the effectiveness of virtual embodiment and play in a social virtual world (Second Life [SL]) for increasing health self-efficacy (exercise and nutrition efficacy) among overweight adults. Participants were randomly assigned to a 3D social virtual world (avatar virtual interaction experimental condition), 2D social networking site (no avatar virtual interaction control condition), or no intervention (no virtual interaction control condition). The findings of this study provide initial evidence for the use of SL to improve exercise efficacy and to support weight loss. Results also suggest that individuals who have higher self-presence with their avatar reap more benefits. Finally, quantitative findings are triangulated with qualitative data to increase confidence in the results and provide richer insight into the perceived effectiveness and limitations of SL for meeting weight loss goals. Themes resulting from the qualitative analysis indicate that participation in SL can improve motivation and efficacy to try new physical activities; however, individuals who have a dislike for video games may not be benefitted by avatar-based virtual interventions. Implications for research on the transformative potential of virtual embodiment and self-presence in general are discussed.

The use of virtual reality in memory rehabilitation: current findings and future directions.

PubMed

Brooks, B M; Rose, F D

2003-01-01

There is considerable potential for using virtual reality (VR) in memory rehabilitation which is only just beginning to be realized. PC-based virtual environments are probably better suited for this purpose than more immersive virtual environments because they are relatively inexpensive and portable, and less frightening to patients. Those exploratory studies that have so far been performed indicate that VR involvement would be usefully directed towards improving assessments of memory impairments and in memory remediation using reorganization techniques. In memory assessment, the use of VR could provide more comprehensive, ecologically-valid, and controlled evaluations of prospective, incidental, and spatial memory in a rehabilitation setting than is possible using standardized assessment tests. The additional knowledge gained from these assessments could more effectively direct rehabilitation towards specific impairments of individual patients. In memory remediation, VR training has been found to promote procedural learning in people with memory impairments, and this learning has been found to transfer to improved real-world performance. Future research should investigate ways in which the procedural knowledge gained during VR interaction can be adapted to offset the many disabilities which result from different forms of memory impairment.

Nomad devices for interactions in immersive virtual environments

NASA Astrophysics Data System (ADS)

George, Paul; Kemeny, Andras; Merienne, Frédéric; Chardonnet, Jean-Rémy; Thouvenin, Indira Mouttapa; Posselt, Javier; Icart, Emmanuel

2013-03-01

Renault is currently setting up a new CAVE™, a 5 rear-projected wall virtual reality room with a combined 3D resolution of 100 Mpixels, distributed over sixteen 4k projectors and two 2k projector as well as an additional 3D HD collaborative powerwall. Renault's CAVE™ aims at answering needs of the various vehicle conception steps [1]. Starting from vehicle Design, through the subsequent Engineering steps, Ergonomic evaluation and perceived quality control, Renault has built up a list of use-cases and carried out an early software evaluation in the four sided CAVE™ of Institute Image, called MOVE. One goal of the project is to study interactions in a CAVE™, especially with nomad devices such as IPhone or IPad to manipulate virtual objects and to develop visualization possibilities. Inspired by nomad devices current uses (multi-touch gestures, IPhone UI look'n'feel and AR applications), we have implemented an early feature set taking advantage of these popular input devices. In this paper, we present its performance through measurement data collected in our test platform, a 4-sided homemade low-cost virtual reality room, powered by ultra-short-range and standard HD home projectors.

Effects on Training Using Illumination in Virtual Environments

NASA Technical Reports Server (NTRS)

Maida, James C.; Novak, M. S. Jennifer; Mueller, Kristian

1999-01-01

Camera based tasks are commonly performed during orbital operations, and orbital lighting conditions, such as high contrast shadowing and glare, are a factor in performance. Computer based training using virtual environments is a common tool used to make and keep CTW members proficient. If computer based training included some of these harsh lighting conditions, would the crew increase their proficiency? The project goal was to determine whether computer based training increases proficiency if one trains for a camera based task using computer generated virtual environments with enhanced lighting conditions such as shadows and glare rather than color shaded computer images normally used in simulators. Previous experiments were conducted using a two degree of freedom docking system. Test subjects had to align a boresight camera using a hand controller with one axis of rotation and one axis of rotation. Two sets of subjects were trained on two computer simulations using computer generated virtual environments, one with lighting, and one without. Results revealed that when subjects were constrained by time and accuracy, those who trained with simulated lighting conditions performed significantly better than those who did not. To reinforce these results for speed and accuracy, the task complexity was increased.

Association of Structured Virtual Visits for Hypertension Follow-Up in Primary Care with Blood Pressure Control and Use of Clinical Services.

PubMed

Levine, David Michael; Dixon, Ronald F; Linder, Jeffrey A

2018-04-23

Optimal management of hypertension requires frequent monitoring and follow-up. Novel, pragmatic interventions have the potential to engage patients, maintain blood pressure control, and enhance access to busy primary care practices. "Virtual visits" are structured asynchronous online interactions between a patient and a clinician to extend medical care beyond the initial office visit. To compare blood pressure control and healthcare utilization between patients who received virtual visits compared to usual hypertension care. Propensity score-matched, retrospective cohort study with adjustment by difference-in-differences. Primary care patients with hypertension. Patient participation in at least one virtual visit for hypertension. Usual care patients did not use a virtual visit but were seen in-person for hypertension. Adjusted difference in mean systolic blood pressure, primary care office visits, specialist office visits, emergency department visits, and inpatient admissions in the 180 days before and 180 days after the in-person visit. Of the 1051 virtual visit patients and 24,848 usual care patients, we propensity score-matched 893 patients from each group. Both groups were approximately 61 years old, 44% female, 85% White, had about five chronic conditions, and about 20% had a mean pre-visit systolic blood pressure of 140-160 mmHg. Compared to usual care, virtual visit patients had an adjusted 0.8 (95% CI, 0.3 to 1.2) fewer primary care office visits. There was no significant adjusted difference in systolic blood pressure control (0.6 mmHg [95% CI, - 2.0 to 3.1]), specialist visits (0.0 more visits [95% CI, - 0.3 to 0.3]), emergency department visits (0.0 more visits [95% CI, 0.0 to 0.01]), or inpatient admissions (0.0 more admissions [95% CI, 0.0 to 0.1]). Among patients with reasonably well-controlled hypertension, virtual visit participation was associated with equivalent blood pressure control and reduced in-office primary care utilization.

Age effect on components of episodic memory and feature binding: A virtual reality study.

PubMed

Plancher, Gaën; Gyselinck, Valerie; Nicolas, Serge; Piolino, Pascale

2010-05-01

The aims were (1) to explore the effects of normal aging on the main aspects of episodic memory--what, where, and when,--and on feature binding in a virtual environment; (2) to explore the influence of the mode of learning, intentional versus incidental; and (3) to benchmark virtual environment findings collected with older adults against data recorded in classical neuropsychological tests. We tested a population of 82 young adults and 78 older adults without dementia (they participated in a short battery of neuropsychological tests). All the participants drove a car in an urban virtual environment composing of 9 turns and specific areas. Half of the participants were told to drive through the virtual town; the other half were asked to drive and to memorize the environment (itinerary, elements, etc.). All aspects of episodic memory were then assessed (what, where, when, and binding). The older participants had less recollection of the spatiotemporal context of events than the younger with intentional encoding (p < .001), but similar recollection with incidental encoding (except for verbal spatial aspect). The younger participants showed better binding than older ones regardless of the type of encoding (p < .001). For the older participants the virtual test was sensitive to mnesic complaints as well as general cognitive changes (p < .05 to p < .01). We view these results as an indication that virtual environments could provide helpful standard tools for assessing age effects on the main aspects of episodic memory.

Effects of a Haptic Augmented Simulation on K-12 Students' Achievement and Their Attitudes Towards Physics

ERIC Educational Resources Information Center

Civelek, Turhan; Ucar, Erdem; Ustunel, Hakan; Aydin, Mehmet Kemal

2014-01-01

The current research aims to explore the effects of a haptic augmented simulation on students' achievement and their attitudes towards Physics in an immersive virtual reality environment (VRE). A quasi-experimental post-test design was employed utilizing experiment and control groups. The participants were 215 students from a K-12 school in…

Virtual visual effect of hospital waiting room on pain modulation in healthy subjects and patients with chronic migraine.

PubMed

de Tommaso, Marina; Ricci, Katia; Laneve, Luigi; Savino, Nicola; Antonaci, Vincenzo; Livrea, Paolo

2013-01-01

Environmental context has an important impact on health and well being. We aimed to test the effects of a visual distraction induced by classical hospital waiting room (RH) versus an ideal room with a sea view (IH), both represented in virtual reality (VR), on subjective sensation and cortical responses induced by painful laser stimuli (LEPs) in healthy volunteers and patients with chronic migraine (CM). Sixteen CM and 16 controls underwent 62 channels LEPs from the right hand, during a fully immersive VR experience, where two types of waiting rooms were simulated. The RH simulated a classical hospital waiting room while the IH represented a room with sea viewing. CM patients showed a reduction of laser pain rating and vertex LEPs during the IH vision. The sLORETA analysis confirmed that in CM patients the two VR simulations induced a different modulation of bilateral parietal cortical areas (precuneus and superior parietal lobe), and superior frontal and cingulate girus, in respect to controls. The architectural context may interfere with pain perception, depending upon the status of subject. Many variables may change patients' outcome and support the use of VR technology to test the best conditions for their management.

Portable Virtual Training Units

NASA Technical Reports Server (NTRS)

Malone, Reagan; Johnston, Alan

2015-01-01

The Mission Operations Lab initiated a project to design, develop, deliver, test, and validate a unique training system for astronaut and ground support personnel. In an effort to keep training costs low, virtual training units (VTUs) have been designed based on images of actual hardware and manipulated by a touch screen style interface for ground support personnel training. This project helped modernized the training system and materials by integrating them with mobile devices for training when operators or crew are unavailable to physically train in the facility. This project also tested the concept of a handheld remote device to control integrated trainers using International Space Station (ISS) training simulators as a platform. The portable VTU can interface with the full-sized VTU, allowing a trainer co-located with a trainee to remotely manipulate a VTU and evaluate a trainee's response. This project helped determine if it is useful, cost effective, and beneficial for the instructor to have a portable handheld device to control the behavior of the models during training. This project has advanced NASA Marshall Space Flight Center's (MSFC's) VTU capabilities with modern and relevant technology to support space flight training needs of today and tomorrow.

Logistic Model to Support Service Modularity for the Promotion of Reusability in a Web Objects-Enabled IoT Environment.

PubMed

Kibria, Muhammad Golam; Ali, Sajjad; Jarwar, Muhammad Aslam; Kumar, Sunil; Chong, Ilyoung

2017-09-22

Due to a very large number of connected virtual objects in the surrounding environment, intelligent service features in the Internet of Things requires the reuse of existing virtual objects and composite virtual objects. If a new virtual object is created for each new service request, then the number of virtual object would increase exponentially. The Web of Objects applies the principle of service modularity in terms of virtual objects and composite virtual objects. Service modularity is a key concept in the Web Objects-Enabled Internet of Things (IoT) environment which allows for the reuse of existing virtual objects and composite virtual objects in heterogeneous ontologies. In the case of similar service requests occurring at the same, or different locations, the already-instantiated virtual objects and their composites that exist in the same, or different ontologies can be reused. In this case, similar types of virtual objects and composite virtual objects are searched and matched. Their reuse avoids duplication under similar circumstances, and reduces the time it takes to search and instantiate them from their repositories, where similar functionalities are provided by similar types of virtual objects and their composites. Controlling and maintaining a virtual object means controlling and maintaining a real-world object in the real world. Even though the functional costs of virtual objects are just a fraction of those for deploying and maintaining real-world objects, this article focuses on reusing virtual objects and composite virtual objects, as well as discusses similarity matching of virtual objects and composite virtual objects. This article proposes a logistic model that supports service modularity for the promotion of reusability in the Web Objects-enabled IoT environment. Necessary functional components and a flowchart of an algorithm for reusing composite virtual objects are discussed. Also, to realize the service modularity, a use case scenario is studied and implemented.

Logistic Model to Support Service Modularity for the Promotion of Reusability in a Web Objects-Enabled IoT Environment

PubMed Central

Chong, Ilyoung

2017-01-01

Due to a very large number of connected virtual objects in the surrounding environment, intelligent service features in the Internet of Things requires the reuse of existing virtual objects and composite virtual objects. If a new virtual object is created for each new service request, then the number of virtual object would increase exponentially. The Web of Objects applies the principle of service modularity in terms of virtual objects and composite virtual objects. Service modularity is a key concept in the Web Objects-Enabled Internet of Things (IoT) environment which allows for the reuse of existing virtual objects and composite virtual objects in heterogeneous ontologies. In the case of similar service requests occurring at the same, or different locations, the already-instantiated virtual objects and their composites that exist in the same, or different ontologies can be reused. In this case, similar types of virtual objects and composite virtual objects are searched and matched. Their reuse avoids duplication under similar circumstances, and reduces the time it takes to search and instantiate them from their repositories, where similar functionalities are provided by similar types of virtual objects and their composites. Controlling and maintaining a virtual object means controlling and maintaining a real-world object in the real world. Even though the functional costs of virtual objects are just a fraction of those for deploying and maintaining real-world objects, this article focuses on reusing virtual objects and composite virtual objects, as well as discusses similarity matching of virtual objects and composite virtual objects. This article proposes a logistic model that supports service modularity for the promotion of reusability in the Web Objects-enabled IoT environment. Necessary functional components and a flowchart of an algorithm for reusing composite virtual objects are discussed. Also, to realize the service modularity, a use case scenario is studied and implemented. PMID:28937590

An immersive virtual peer for studying social influences on child cyclists' road-crossing behavior.

PubMed

Babu, Sabarish V; Grechkin, Timofey Y; Chihak, Benjamin; Ziemer, Christine; Kearney, Joseph K; Cremer, James F; Plumert, Jodie M

2011-01-01

The goal of our work is to develop a programmatically controlled peer to bicycle with a human subject for the purpose of studying how social interactions influence road-crossing behavior. The peer is controlled through a combination of reactive controllers that determine the gross motion of the virtual bicycle, action-based controllers that animate the virtual bicyclist and generate verbal behaviors, and a keyboard interface that allows an experimenter to initiate the virtual bicyclist's actions during the course of an experiment. The virtual bicyclist's repertoire of behaviors includes road following, riding alongside the human rider, stopping at intersections, and crossing intersections through specified gaps in traffic. The virtual cyclist engages the human subject through gaze, gesture, and verbal interactions. We describe the structure of the behavior code and report the results of a study examining how 10- and 12-year-old children interact with a peer cyclist that makes either risky or safe choices in selecting gaps in traffic. Results of our study revealed that children who rode with a risky peer were more likely to cross intermediate-sized gaps than children who rode with a safe peer. In addition, children were significantly less likely to stop at the last six intersections after the experience of riding with the risky than the safe peer during the first six intersections. The results of the study and children's reactions to the virtual peer indicate that our virtual peer framework is a promising platform for future behavioral studies of peer influences on children's bicycle riding behavior. © 2011 IEEE Published by the IEEE Computer Society

Effectiveness of the Multilayered Caries Model and Visuo-tactile Virtual Reality Simulator for Minimally Invasive Caries Removal: A Randomized Controlled Trial.

PubMed

Dwisaptarini, A P; Suebnukarn, S; Rhienmora, P; Haddawy, P; Koontongkaew, S

This work presents the multilayered caries model with a visuo-tactile virtual reality simulator and a randomized controlled trial protocol to determine the effectiveness of the simulator in training for minimally invasive caries removal. A three-dimensional, multilayered caries model was reconstructed from 10 micro-computed tomography (CT) images of deeply carious extracted human teeth before and after caries removal. The full grey scale 0-255 yielded a median grey scale value of 0-9, 10-18, 19-25, 26-52, and 53-80 regarding dental pulp, infected carious dentin, affected carious dentin, normal dentin, and normal enamel, respectively. The simulator was connected to two haptic devices for a handpiece and mouth mirror. The visuo-tactile feedback during the operation varied depending on the grey scale. Sixth-year dental students underwent a pretraining assessment of caries removal on extracted teeth. The students were then randomly assigned to train on either the simulator (n=16) or conventional extracted teeth (n=16) for 3 days, after which the assessment was repeated. The posttraining performance of caries removal improved compared with pretraining in both groups (Wilcoxon, p<0.05). The equivalence test for proportional differences (two 1-sided t-tests) with a 0.2 margin confirmed that the participants in both groups had identical posttraining performance scores (95% CI=0.92, 1; p=0.00). In conclusion, training on the micro-CT multilayered caries model with the visuo-tactile virtual reality simulator and conventional extracted tooth had equivalent effects on improving performance of minimally invasive caries removal.

Virtual reality-augmented neurorehabilitation improves motor function and reduces neuropathic pain in patients with incomplete spinal cord injury.

PubMed

Villiger, Michael; Bohli, Dominik; Kiper, Daniel; Pyk, Pawel; Spillmann, Jeremy; Meilick, Bruno; Curt, Armin; Hepp-Reymond, Marie-Claude; Hotz-Boendermaker, Sabina; Eng, Kynan

2013-10-01

Neurorehabilitation interventions to improve lower limb function and neuropathic pain have had limited success in people with chronic, incomplete spinal cord injury (iSCI). We hypothesized that intense virtual reality (VR)-augmented training of observed and executed leg movements would improve limb function and neuropathic pain. Patients used a VR system with a first-person view of virtual lower limbs, controlled via movement sensors fitted to the patient's own shoes. Four tasks were used to deliver intensive training of individual muscles (tibialis anterior, quadriceps, leg ad-/abductors). The tasks engaged motivation through feedback of task success. Fourteen chronic iSCI patients were treated over 4 weeks in 16 to 20 sessions of 45 minutes. Outcome measures were 10 Meter Walking Test, Berg Balance Scale, Lower Extremity Motor Score, Spinal Cord Independence Measure, Locomotion and Neuropathic Pain Scale (NPS), obtained at the start and at 4 to 6 weeks before intervention. In addition to positive changes reported by the patients (Patients' Global Impression of Change), measures of walking capacity, balance, and strength revealed improvements in lower limb function. Intensity and unpleasantness of neuropathic pain in half of the affected participants were reduced on the NPS test. Overall findings remained stable 12 to 16 weeks after termination of the training. In a pretest/posttest, uncontrolled design, VR-augmented training was associated with improvements in motor function and neuropathic pain in persons with chronic iSCI, several of which reached the level of a minimal clinically important change. A controlled trial is needed to compare this intervention to active training alone or in combination.

Robotically facilitated virtual rehabilitation of arm transport integrated with finger movement in persons with hemiparesis.

PubMed

Merians, Alma S; Fluet, Gerard G; Qiu, Qinyin; Saleh, Soha; Lafond, Ian; Davidow, Amy; Adamovich, Sergei V

2011-05-16

Recovery of upper extremity function is particularly recalcitrant to successful rehabilitation. Robotic-assisted arm training devices integrated with virtual targets or complex virtual reality gaming simulations are being developed to deal with this problem. Neural control mechanisms indicate that reaching and hand-object manipulation are interdependent, suggesting that training on tasks requiring coordinated effort of both the upper arm and hand may be a more effective method for improving recovery of real world function. However, most robotic therapies have focused on training the proximal, rather than distal effectors of the upper extremity. This paper describes the effects of robotically-assisted, integrated upper extremity training. Twelve subjects post-stroke were trained for eight days on four upper extremity gaming simulations using adaptive robots during 2-3 hour sessions. The subjects demonstrated improved proximal stability, smoothness and efficiency of the movement path. This was in concert with improvement in the distal kinematic measures of finger individuation and improved speed. Importantly, these changes were accompanied by a robust 16-second decrease in overall time in the Wolf Motor Function Test and a 24-second decrease in the Jebsen Test of Hand Function. Complex gaming simulations interfaced with adaptive robots requiring integrated control of shoulder, elbow, forearm, wrist and finger movements appear to have a substantial effect on improving hemiparetic hand function. We believe that the magnitude of the changes and the stability of the patient's function prior to training, along with maintenance of several aspects of the gains demonstrated at retention make a compelling argument for this approach to training.

Robotically facilitated virtual rehabilitation of arm transport integrated with finger movement in persons with hemiparesis

PubMed Central

2011-01-01

Background Recovery of upper extremity function is particularly recalcitrant to successful rehabilitation. Robotic-assisted arm training devices integrated with virtual targets or complex virtual reality gaming simulations are being developed to deal with this problem. Neural control mechanisms indicate that reaching and hand-object manipulation are interdependent, suggesting that training on tasks requiring coordinated effort of both the upper arm and hand may be a more effective method for improving recovery of real world function. However, most robotic therapies have focused on training the proximal, rather than distal effectors of the upper extremity. This paper describes the effects of robotically-assisted, integrated upper extremity training. Methods Twelve subjects post-stroke were trained for eight days on four upper extremity gaming simulations using adaptive robots during 2-3 hour sessions. Results The subjects demonstrated improved proximal stability, smoothness and efficiency of the movement path. This was in concert with improvement in the distal kinematic measures of finger individuation and improved speed. Importantly, these changes were accompanied by a robust 16-second decrease in overall time in the Wolf Motor Function Test and a 24-second decrease in the Jebsen Test of Hand Function. Conclusions Complex gaming simulations interfaced with adaptive robots requiring integrated control of shoulder, elbow, forearm, wrist and finger movements appear to have a substantial effect on improving hemiparetic hand function. We believe that the magnitude of the changes and the stability of the patient's function prior to training, along with maintenance of several aspects of the gains demonstrated at retention make a compelling argument for this approach to training. PMID:21575185

An Optimized Trajectory Planning for Welding Robot

NASA Astrophysics Data System (ADS)

Chen, Zhilong; Wang, Jun; Li, Shuting; Ren, Jun; Wang, Quan; Cheng, Qunchao; Li, Wentao

2018-03-01

In order to improve the welding efficiency and quality, this paper studies the combined planning between welding parameters and space trajectory for welding robot and proposes a trajectory planning method with high real-time performance, strong controllability and small welding error. By adding the virtual joint at the end-effector, the appropriate virtual joint model is established and the welding process parameters are represented by the virtual joint variables. The trajectory planning is carried out in the robot joint space, which makes the control of the welding process parameters more intuitive and convenient. By using the virtual joint model combined with the B-spline curve affine invariant, the welding process parameters are indirectly controlled by controlling the motion curve of the real joint. To solve the optimal time solution as the goal, the welding process parameters and joint space trajectory joint planning are optimized.

A Feasibility Study of Virtual Reality-Based Coping Skills Training for Nicotine Dependence

PubMed Central

Bordnick, Patrick S.; Traylor, Amy C.; Carter, Brian L.; Graap, Ken M.

2014-01-01

Objective Virtual reality (VR)-based cue reactivity has been successfully used for the assessment of drug craving. Going beyond assessment of cue reactivity, a novel VR-based treatment approach for smoking cessation was developed and tested for feasibility. Method In a randomized experiment, 10-week treatment feasibility trial, 46 nicotine-dependent adults, completed the10-week program. Virtual reality skills training (VRST) combined with nicotine replacement therapy (NRT) was compared to NRT alone. Participants were assessed for smoking behavior and coping skills during, at end of treatment, and at posttreatment follow-up. Results Smoking rates and craving for nicotine were significantly lower for the VRST group compared to NRT-only group at the end of treatment. Self-confidence and coping skills were also significantly higher for the VRST group, and number of cigarettes smoked was significantly lower, compared to the control group at follow-up. Conclusions Feasibility of VRST was supported in the current study. PMID:25484549

An Overview of Virtual Acoustic Simulation of Aircraft Flyover Noise

NASA Technical Reports Server (NTRS)

Rizzi, Stephen A.

2013-01-01

Methods for testing human subject response to aircraft flyover noise have greatly advanced in recent years as a result of advances in simulation technology. Capabilities have been developed which now allow subjects to be immersed both visually and aurally in a three-dimensional, virtual environment. While suitable for displaying recorded aircraft noise, the true potential is found when synthesizing aircraft flyover noise because it allows the flexibility and freedom to study sounds from aircraft not yet flown. A virtual acoustic simulation method is described which is built upon prediction-based source noise synthesis, engineering-based propagation modeling, and empirically-based receiver modeling. This source-path-receiver paradigm allows complete control over all aspects of flyover auralization. With this capability, it is now possible to assess human response to flyover noise by systematically evaluating source noise reductions within the context of a system level simulation. Examples of auralized flyover noise and movie clips representative of an immersive aircraft flyover environment are made in the presentation.

Effects of patient-provider race concordance and smoking status on lung cancer risk perception accuracy among African-Americans.

PubMed

Persky, Susan; Kaphingst, Kimberly A; Allen, Vincent C; Senay, Ibrahim

2013-06-01

Communication of lung cancer risk information between providers and African-American patients occurs in a context marked by race-based health disparities. A controlled experiment assessed whether perceived physician race influenced African-American patients' (n = 127) risk perception accuracy following the provision of objective lung cancer risk information. Participants interacted with a virtual reality-based, simulated physician who provided personalized cancer risk information. Participants who interacted with a racially discordant virtual doctor were less accurate in their risk perceptions at post-test than those who interacted with a concordant virtual doctor, F(1,94) = 4.02, p = .048. This effect was amplified among current smokers. Effects were not mediated by trust in the provider, engagement with the health care system, or attention during the encounter. The current study demonstrates that African-American patients' perceptions of a doctor's race are sufficient to independently impact their processing of lung cancer risk information.

Effects of Patient-Provider Race Concordance and Smoking Status on Lung Cancer Risk Perception Accuracy among African Americans

PubMed Central

Persky, Susan; Kaphingst, Kimberly A.; Allen, Vincent C.; Senay, Ibrahim

2013-01-01

Background Communication of lung cancer risk information between providers and African-American patients occurs in a context marked by race-based health disparities. Purpose A controlled experiment assessed whether perceived physician race influenced African-American patients’ (n=127) risk perception accuracy following the provision of objective lung cancer risk information. Methods Participants interacted with a virtual reality-based, simulated physician who provided personalized cancer risk information. Results Participants who interacted with a racially discordant virtual doctor were less accurate in their risk perceptions at post-test than those who interacted with a concordant virtual doctor, F(1,94)=4.02, p=.048. This effect was amplified among current smokers. Effects were not mediated by trust in the provider, engagement with the health care system, or attention during the encounter. Conclusions The current study demonstrates that African-American patients’ perceptions of a doctor’s race are sufficient to independently impact their processing of lung cancer risk information. PMID:23389688

The roles of consistency and exclusivity in perceiving body ownership and agency.

PubMed

Ma, Ke; Hommel, Bernhard; Chen, Hong

2018-01-23

Previous rubber/virtual hand illusion studies have established important constraints for the illusion that an artificial effector becomes part of one's own body (perceived ownership), and that its actions are being caused by oneself (perceived agency). We can take these observed constraints to establish two of three Wegner's (Trends Cogn Sci 7:65-69; Wegner, Trends in Cognitive Sciences 7:65-69, 2003) criteria for the perception of personal agency: priority and consistency, but not Wegner's third criterion-exclusivity. In this study we tested with virtual hand illusion, whether exclusivity (participant is certain who was controlling the virtual effector) can also be established. We manipulated two factors: exclusivity and consistency. Our results show that on both ownership and agency judgments, consistency and exclusivity produced main effects, and the two effects interacted in an underadditive fashion. Taken together, these findings provide support for our suggestion to extend Wegner's agency theory to explain perceived body ownership, which in turn provides an integrative framework for interpreting constraints on ownership and agency illusions.

Steering Control in a Low-Cost Driving Simulator: A Case for the Role of Virtual Vehicle Cab.

PubMed

Mecheri, Sami; Lobjois, Régis

2018-04-01

The aim of this study was to investigate steering control in a low-cost driving simulator with and without a virtual vehicle cab. In low-cost simulators, the lack of a vehicle cab denies driver access to vehicle width, which could affect steering control, insofar as locomotor adjustments are known to be based on action-scaled visual judgments of the environment. Two experiments were conducted in which steering control with and without a virtual vehicle cab was investigated in a within-subject design, using cornering and straight-lane-keeping tasks. Driving around curves without vehicle cab information made drivers deviate more from the lane center toward the inner edge in right (virtual cab = 4 ± 19 cm; no cab = 42 ± 28 cm; at the apex of the curve, p < .001) but not in left curves. More lateral deviation from the lane center toward the edge line was also found in driving without the virtual cab on straight roads (virtual cab = 21 ± 28 cm; no cab = 36 ± 27 cm; p < .001), whereas driving stability and presence ratings were not affected. In both experiments, the greater lateral deviation in the no-cab condition led to significantly more time driving off the lane. The findings strongly suggest that without cab information, participants underestimate the distance to the right edge of the car (in contrast to the left edge) and thus vehicle width. This produces considerable differences in the steering trajectory. Providing a virtual vehicle cab must be encouraged for more effectively capturing drivers' steering control in low-cost simulators.

Virtual Reality and Medical Inpatients: A Systematic Review of Randomized, Controlled Trials

PubMed Central

Dascal, Julieta; Reid, Mark; IsHak, Waguih William; Spiegel, Brennan; Recacho, Jennifer; Rosen, Bradley

2017-01-01

Objective: We evaluated the evidence supporting the use of virtual reality among patients in acute inpatient medical settings. Method: We conducted a systematic review of randomized controlled trials conducted that examined virtual reality applications in inpatient medical settings between 2005 and 2015. We used PsycINFO, PubMed, and Medline databases to identify studies using the keywords virtual reality, VR therapy, treatment, and inpatient. Results: We identified 2,024 citations, among which 11 met criteria for inclusion. Studies addressed three general areas: pain management, eating disorders, and cognitive and motor rehabilitation. Studies were small and heterogeneous and utilized different designs and measures. Virtual reality was generally well tolerated by patients, and a majority of studies demonstrated clinical efficacy. Studies varied in quality, as measured by an evaluation metric developed by Reisch, Tyson, and Mize (average quality score=0.87; range=0.78–0.96). Conclusion: Virtual reality is a promising intervention with several potential applications in the inpatient medical setting. Studies to date demonstrate some efficacy, but there is a need for larger, well-controlled studies to show clinical and cost-effectiveness. PMID:28386517

Virtual Reality and Medical Inpatients: A Systematic Review of Randomized, Controlled Trials.

PubMed

Dascal, Julieta; Reid, Mark; IsHak, Waguih William; Spiegel, Brennan; Recacho, Jennifer; Rosen, Bradley; Danovitch, Itai

2017-01-01

Objective: We evaluated the evidence supporting the use of virtual reality among patients in acute inpatient medical settings. Method: We conducted a systematic review of randomized controlled trials conducted that examined virtual reality applications in inpatient medical settings between 2005 and 2015. We used PsycINFO, PubMed, and Medline databases to identify studies using the keywords virtual reality , VR therapy , treatment , and inpatient. Results: We identified 2,024 citations, among which 11 met criteria for inclusion. Studies addressed three general areas: pain management, eating disorders, and cognitive and motor rehabilitation. Studies were small and heterogeneous and utilized different designs and measures. Virtual reality was generally well tolerated by patients, and a majority of studies demonstrated clinical efficacy. Studies varied in quality, as measured by an evaluation metric developed by Reisch, Tyson, and Mize (average quality score=0.87; range=0.78-0.96). Conclusion: Virtual reality is a promising intervention with several potential applications in the inpatient medical setting. Studies to date demonstrate some efficacy, but there is a need for larger, well-controlled studies to show clinical and cost-effectiveness.

Verbalizing, Visualizing, and Navigating: The Effect of Strategies on Encoding a Large-Scale Virtual Environment

ERIC Educational Resources Information Center

Kraemer, David J. M.; Schinazi, Victor R.; Cawkwell, Philip B.; Tekriwal, Anand; Epstein, Russell A.; Thompson-Schill, Sharon L.

2017-01-01

Using novel virtual cities, we investigated the influence of verbal and visual strategies on the encoding of navigation-relevant information in a large-scale virtual environment. In 2 experiments, participants watched videos of routes through 4 virtual cities and were subsequently tested on their memory for observed landmarks and their ability to…

Does Virtual Team Composition Matter? Trait and Problem-Solving Configuration Effects on Team Performance

ERIC Educational Resources Information Center

Turel, Ofir; Zhang, Yi

2010-01-01

Due to the increased importance and usage of self-managed virtual teams, many recent studies have examined factors that affect their success. One such factor that merits examination is the configuration or composition of virtual teams. This article tackles this point by (1) empirically testing trait-configuration effects on virtual team…

Applying a 3D Situational Virtual Learning Environment to the Real World Business--An Extended Research in Marketing

ERIC Educational Resources Information Center

Wang, Shwu-huey

2012-01-01

In order to understand (1) what kind of students can be facilitated through the help of three-dimensional virtual learning environment (3D VLE), and (2) the relationship between a conventional test (ie, paper and pencil test) and the 3D VLE used in this study, the study designs a 3D virtual supermarket (3DVS) to help students transform their role…

A randomized, controlled trial of immersive virtual reality analgesia, during physical therapy for pediatric burns.

PubMed

Schmitt, Yuko S; Hoffman, Hunter G; Blough, David K; Patterson, David R; Jensen, Mark P; Soltani, Maryam; Carrougher, Gretchen J; Nakamura, Dana; Sharar, Sam R

2011-02-01

This randomized, controlled, within-subjects (crossover design) study examined the effects of immersive virtual reality as an adjunctive analgesic technique for hospitalized pediatric burn inpatients undergoing painful physical therapy. Fifty-four subjects (6-19 years old) performed range-of-motion exercises under a therapist's direction for 1-5 days. During each session, subjects spent equivalent time in both the virtual reality and the control conditions (treatment order randomized and counterbalanced). Graphic rating scale scores assessing the sensory, affective, and cognitive components of pain were obtained for each treatment condition. Secondary outcomes assessed subjects' perception of the virtual reality experience and maximum range-of-motion. Results showed that on study day one, subjects reported significant decreases (27-44%) in pain ratings during virtual reality. They also reported improved affect ("fun") during virtual reality. The analgesia and affect improvements were maintained with repeated virtual reality use over multiple therapy sessions. Maximum range-of-motion was not different between treatment conditions, but was significantly greater after the second treatment condition (regardless of treatment order). These results suggest that immersive virtual reality is an effective nonpharmacologic, adjunctive pain reduction technique in the pediatric burn population undergoing painful rehabilitation therapy. The magnitude of the analgesic effect is clinically meaningful and is maintained with repeated use. Copyright © 2010 Elsevier Ltd and ISBI. All rights reserved.

A Randomized, Controlled Trial of Immersive Virtual Reality Analgesia during Physical Therapy for Pediatric Burn Injuries

PubMed Central

Schmitt, Yuko S.; Hoffman, Hunter G.; Blough, David K.; Patterson, David R.; Jensen, Mark P.; Soltani, Maryam; Carrougher, Gretchen J.; Nakamura, Dana; Sharar, Sam R.

2010-01-01

This randomized, controlled, within-subjects (crossover design) study examined the effects of immersive virtual reality as an adjunctive analgesic technique for hospitalized pediatric burn inpatients undergoing painful physical therapy. Fifty-four subjects (6–19 years old) performed range-of-motion exercises under a therapist’s direction for one to five days. During each session, subjects spent equivalent time in both the virtual reality and the control conditions (treatment order randomized and counterbalanced). Graphic rating scale scores assessing the sensory, affective, and cognitive components of pain were obtained for each treatment condition. Secondary outcomes assessed subjects’ perception of the virtual reality experience and maximum range-of-motion. Results showed that on study day one, subjects reported significant decreases (27–44%) in pain ratings during virtual reality. They also reported improved affect (“fun”) during virtual reality. The analgesia and affect improvements were maintained with repeated virtual reality use over multiple therapy sessions. Maximum range-of-motion was not different between treatment conditions, but was significantly greater after the second treatment condition (regardless of treatment order). These results suggest that immersive virtual reality is an effective nonpharmacologic, adjunctive pain reduction technique in the pediatric burn population undergoing painful rehabilitation therapy. The magnitude of the analgesic effect is clinically meaningful and is maintained with repeated use. PMID:20692769

Can we use virtual reality tools in the planning of an experiment?

NASA Astrophysics Data System (ADS)

Kucaba-Pietal, Anna; Szumski, Marek; Szczerba, Piotr

2015-03-01

Virtual reality (VR) has proved to be a particularly useful tool in engineering and design. A related area of aviation in which VR is particularly significant is a flight training, as it requires many hours of practice and using real planes for all training is both expensive and more dangerous. Research conducted at the Rzeszow University of Technology (RUT) showed that virtual reality can be successfully used for planning experiment during a flight tests. Motivation to the study were a wing deformation measurements of PW-6 glider in flight by use Image Pattern Correlation Technique (IPCT) planned within the frame of AIM2 project. The tool VirlIPCT was constructed, which permits to perform virtual IPCT setup on an airplane. Using it, we can test a camera position, camera resolution, pattern application. Moreover performed tests on RUT indicate, that VirlIPCT can be used as a virtual IPCT image generator. This paper presents results of the research on VirlIPCT.

Virtual Control Systems Environment (VCSE)

ScienceCinema

Atkins, Will

2018-02-14

Will Atkins, a Sandia National Laboratories computer engineer discusses cybersecurity research work for process control systems. Will explains his work on the Virtual Control Systems Environment project to develop a modeling and simulation framework of the U.S. electric grid in order to study and mitigate possible cyberattacks on infrastructure.

Utility of virtual reality environments to examine physiological reactivity and subjective distress in adults who stutter.

PubMed

Brundage, Shelley B; Brinton, James M; Hancock, Adrienne B

2016-12-01

Virtual reality environments (VREs) allow for immersion in speaking environments that mimic real-life interactions while maintaining researcher control. VREs have been used successfully to engender arousal in other disorders. The purpose of this study was to investigate the utility of virtual reality environments to examine physiological reactivity and subjective ratings of distress in persons who stutter (PWS). Subjective and objective measures of arousal were collected from 10PWS during four-minute speeches to a virtual audience and to a virtual empty room. Stuttering frequency and physiological measures (skin conductance level and heart rate) did not differ across speaking conditions, but subjective ratings of distress were significantly higher in the virtual audience condition compared to the virtual empty room. VREs have utility in elevating subjective ratings of distress in PWS. VREs have the potential to be useful tools for practicing treatment targets in a safe, controlled, and systematic manner. Copyright © 2016 Elsevier Inc. All rights reserved.

Use of virtual reality technique for the training of motor control in the elderly. Some theoretical considerations.

PubMed

de Bruin, E D; Schoene, D; Pichierri, G; Smith, S T

2010-08-01

Virtual augmented exercise, an emerging technology that can help to promote physical activity and combine the strengths of indoor and outdoor exercise, has recently been proposed as having the potential to increase exercise behavior in older adults. By creating a strong presence in a virtual, interactive environment, distraction can be taken to greater levels while maintaining the benefits of indoor exercises which may result in a shift from negative to positive thoughts about exercise. Recent findings on young participants show that virtual reality training enhances mood, thus, increasing enjoyment and energy. For older adults virtual, interactive environments can influence postural control and fall events by stimulating the sensory cues that are responsible in maintaining balance and orientation. However, the potential of virtual reality training has yet to be explored for older adults. This manuscript describes the potential of dance pad training protocols in the elderly and reports on the theoretical rationale of combining physical game-like exercises with sensory and cognitive challenges in a virtual environment.

Working Group Reports and Presentations: Virtual Worlds and Virtual Exploration

NASA Technical Reports Server (NTRS)

LAmoreaux, Claudia

2006-01-01

Scientists and engineers are continually developing innovative methods to capitalize on recent developments in computational power. Virtual worlds and virtual exploration present a new toolset for project design, implementation, and resolution. Replication of the physical world in the virtual domain provides stimulating displays to augment current data analysis techniques and to encourage public participation. In addition, the virtual domain provides stakeholders with a low cost, low risk design and test environment. The following document defines a virtual world and virtual exploration, categorizes the chief motivations for virtual exploration, elaborates upon specific objectives, identifies roadblocks and enablers for realizing the benefits, and highlights the more immediate areas of implementation (i.e. the action items). While the document attempts a comprehensive evaluation of virtual worlds and virtual exploration, the innovative nature of the opportunities presented precludes completeness. The authors strongly encourage readers to derive additional means of utilizing the virtual exploration toolset.

Protecting Sensitive Information in Directory Services Using Virtual Directories

NASA Astrophysics Data System (ADS)

Claycomb, William; Shin, Dongwan

Directory services are commonly used to store information related to individuals, and often act as a source for security services, such as authentication and access control, in collaborative applications within/across organizations. Hence, there is an urgent need to protect the sensitive information they contain. Existing solutions offer minimal protection against insider attacks, a growing threat to both government and industry data services. In this paper we present a solution for data protection that leverages virtual directories and data encryption to provide a user-centric approach to data protection, delegation, and collaboration. A security architecture is presented, along with the discussion of the benefits and vulnerabilities of our approach. We also discuss a proof-of-concept implementation and performance testing results.

Virtual gap dielectric wall accelerator

DOEpatents

Caporaso, George James; Chen, Yu-Jiuan; Nelson, Scott; Sullivan, Jim; Hawkins, Steven A

2013-11-05

A virtual, moving accelerating gap is formed along an insulating tube in a dielectric wall accelerator (DWA) by locally controlling the conductivity of the tube. Localized voltage concentration is thus achieved by sequential activation of a variable resistive tube or stalk down the axis of an inductive voltage adder, producing a "virtual" traveling wave along the tube. The tube conductivity can be controlled at a desired location, which can be moved at a desired rate, by light illumination, or by photoconductive switches, or by other means. As a result, an impressed voltage along the tube appears predominantly over a local region, the virtual gap. By making the length of the tube large in comparison to the virtual gap length, the effective gain of the accelerator can be made very large.

Importance of Virtual Reality to Virtual Reality Exposure Therapy, Study Design of a Randomized Trial.

PubMed

McLay, Robert N; Baird, Alicia; Murphy, Jennifer; Deal, William; Tran, Lily; Anson, Heather; Klam, Warren; Johnston, Scott

2015-01-01

Post Traumatic Stress Disorder (PTSD) can be a debilitating problem in service members who have served in Iraq or Afghanistan. Virtual Reality Exposure Therapy (VRET) is one of the few interventions demonstrated in randomized controlled trials to be effective for PTSD in this population. There are theoretical reasons to expect that Virtual Reality (VR) adds to the effectiveness of exposure therapy, but there is also added expense and difficulty in using VR. Described is a trial comparing outcomes from VRET and a control exposure therapy (CET) protocol in service members with PTSD.

Inertial Sensor-Based Touch and Shake Metaphor for Expressive Control of 3D Virtual Avatars

PubMed Central

Patil, Shashidhar; Chintalapalli, Harinadha Reddy; Kim, Dubeom; Chai, Youngho

2015-01-01

In this paper, we present an inertial sensor-based touch and shake metaphor for expressive control of a 3D virtual avatar in a virtual environment. An intuitive six degrees-of-freedom wireless inertial motion sensor is used as a gesture and motion control input device with a sensor fusion algorithm. The algorithm enables user hand motions to be tracked in 3D space via magnetic, angular rate, and gravity sensors. A quaternion-based complementary filter is implemented to reduce noise and drift. An algorithm based on dynamic time-warping is developed for efficient recognition of dynamic hand gestures with real-time automatic hand gesture segmentation. Our approach enables the recognition of gestures and estimates gesture variations for continuous interaction. We demonstrate the gesture expressivity using an interactive flexible gesture mapping interface for authoring and controlling a 3D virtual avatar and its motion by tracking user dynamic hand gestures. This synthesizes stylistic variations in a 3D virtual avatar, producing motions that are not present in the motion database using hand gesture sequences from a single inertial motion sensor. PMID:26094629

Simulated airline service experience with laminar-flow control leading-edge systems

NASA Technical Reports Server (NTRS)

Maddalon, Dal V.; Fisher, David F.; Jennett, Lisa A.; Fischer, Michael C.

1987-01-01

The first JetStar leading edge flight test was made November 30, 1983. The JetStar was flown for more than 3 years. The titanium leading edge test articles today remain in virtually the same condition as they were in on that first flight. No degradation of laminar flow performance has occurred as a result of service. The JetStar simulated airline service flights have demonstrated that effective, practical leading edge systems are available for future commercial transports. Specific conclusions based on the results of the simulated airline service test program are summarized.

Analyzing a multimodal biometric system using real and virtual users

NASA Astrophysics Data System (ADS)

Scheidat, Tobias; Vielhauer, Claus

2007-02-01

Three main topics of recent research on multimodal biometric systems are addressed in this article: The lack of sufficiently large multimodal test data sets, the influence of cultural aspects and data protection issues of multimodal biometric data. In this contribution, different possibilities are presented to extend multimodal databases by generating so-called virtual users, which are created by combining single biometric modality data of different users. Comparative tests on databases containing real and virtual users based on a multimodal system using handwriting and speech are presented, to study to which degree the use of virtual multimodal databases allows conclusions with respect to recognition accuracy in comparison to real multimodal data. All tests have been carried out on databases created from donations from three different nationality groups. This allows to review the experimental results both in general and in context of cultural origin. The results show that in most cases the usage of virtual persons leads to lower accuracy than the usage of real users in terms of the measurement applied: the Equal Error Rate. Finally, this article will address the general question how the concept of virtual users may influence the data protection requirements for multimodal evaluation databases in the future.

Instrumentation to Aid in Steel Bridge Fabrication : Bridge Virtual Assembly System

DOT National Transportation Integrated Search

2018-05-01

This pool funded project developed a BRIDGE VIRTUAL ASSEMBLY SYSTEM (BRIDGE VAS) that improves manufacturing processes and enhances quality control for steel bridge fabrication. The system replaces conventional match-drilling with virtual assembly me...

Sensor supervision and multiagent commanding by means of projective virtual reality

NASA Astrophysics Data System (ADS)

Rossmann, Juergen

1998-10-01

When autonomous systems with multiple agents are considered, conventional control- and supervision technologies are often inadequate because the amount of information available is often presented in a way that the user is effectively overwhelmed by the displayed data. New virtual reality (VR) techniques can help to cope with this problem, because VR offers the chance to convey information in an intuitive manner and can combine supervision capabilities and new, intuitive approaches to the control of autonomous systems. In the approach taken, control and supervision issues were equally stressed and finally led to the new ideas and the general framework for Projective Virtual Reality. The key idea of this new approach for an intuitively operable man machine interface for decentrally controlled multi-agent systems is to let the user act in the virtual world, detect the changes and have an action planning component automatically generate task descriptions for the agents involved to project actions that have been carried out by users in the virtual world into the physical world, e.g. with the help of robots. Thus the Projective Virtual Reality approach is to split the job between the task deduction in the VR and the task `projection' onto the physical automation components by the automatic action planning component. Besides describing the realized projective virtual reality system, the paper will also describe in detail the metaphors and visualization aids used to present different types of (e.g. sensor-) information in an intuitively comprehensible manner.

Virtual Deformation Control of the X-56A Model with Simulated Fiber Optic Sensors

NASA Technical Reports Server (NTRS)

Suh, Peter M.; Chin, Alexander W.; Mavris, Dimitri N.

2014-01-01

A robust control law design methodology is presented to stabilize the X-56A model and command its wing shape. The X-56A was purposely designed to experience flutter modes in its flight envelope. The methodology introduces three phases: the controller design phase, the modal filter design phase, and the reference signal design phase. A mu-optimal controller is designed and made robust to speed and parameter variations. A conversion technique is presented for generating sensor strain modes from sensor deformation mode shapes. The sensor modes are utilized for modal filtering and simulating fiber optic sensors for feedback to the controller. To generate appropriate virtual deformation reference signals, rigid-body corrections are introduced to the deformation mode shapes. After successful completion of the phases, virtual deformation control is demonstrated. The wing is deformed and it is shown that angle-ofattack changes occur which could potentially be used to an advantage. The X-56A program must demonstrate active flutter suppression. It is shown that the virtual deformation controller can achieve active flutter suppression on the X-56A simulation model.

Virtual Deformation Control of the X-56A Model with Simulated Fiber Optic Sensors

NASA Technical Reports Server (NTRS)

Suh, Peter M.; Chin, Alexander Wong

2013-01-01

A robust control law design methodology is presented to stabilize the X-56A model and command its wing shape. The X-56A was purposely designed to experience flutter modes in its flight envelope. The methodology introduces three phases: the controller design phase, the modal filter design phase, and the reference signal design phase. A mu-optimal controller is designed and made robust to speed and parameter variations. A conversion technique is presented for generating sensor strain modes from sensor deformation mode shapes. The sensor modes are utilized for modal filtering and simulating fiber optic sensors for feedback to the controller. To generate appropriate virtual deformation reference signals, rigid-body corrections are introduced to the deformation mode shapes. After successful completion of the phases, virtual deformation control is demonstrated. The wing is deformed and it is shown that angle-of-attack changes occur which could potentially be used to an advantage. The X-56A program must demonstrate active flutter suppression. It is shown that the virtual deformation controller can achieve active flutter suppression on the X-56A simulation model.

Testing of visual field with virtual reality goggles in manual and visual grasp modes.

PubMed

Wroblewski, Dariusz; Francis, Brian A; Sadun, Alfredo; Vakili, Ghazal; Chopra, Vikas

2014-01-01

Automated perimetry is used for the assessment of visual function in a variety of ophthalmic and neurologic diseases. We report development and clinical testing of a compact, head-mounted, and eye-tracking perimeter (VirtualEye) that provides a more comfortable test environment than the standard instrumentation. VirtualEye performs the equivalent of a full threshold 24-2 visual field in two modes: (1) manual, with patient response registered with a mouse click, and (2) visual grasp, where the eye tracker senses change in gaze direction as evidence of target acquisition. 59 patients successfully completed the test in manual mode and 40 in visual grasp mode, with 59 undergoing the standard Humphrey field analyzer (HFA) testing. Large visual field defects were reliably detected by VirtualEye. Point-by-point comparison between the results obtained with the different modalities indicates: (1) minimal systematic differences between measurements taken in visual grasp and manual modes, (2) the average standard deviation of the difference distributions of about 5 dB, and (3) a systematic shift (of 4-6 dB) to lower sensitivities for VirtualEye device, observed mostly in high dB range. The usability survey suggested patients' acceptance of the head-mounted device. The study appears to validate the concepts of a head-mounted perimeter and the visual grasp mode.

Tests for a disease-susceptibility locus allowing for an inbreeding coefficient (F).

PubMed

Song, Kijoung; Elston, Robert C

2003-11-01

We begin by discussing the false positive test results that arise because of cryptic relatedness and population substructure when testing a disease susceptibility locus. We extend and evaluate the Hardy-Weinberg disequilibrium (HWD) method, allowing for an inbreeding coefficient (F) in a similar way that Devlin and Roeder (1999) allowed for inbreeding in a case-control study. Then we compare the HWD measure and the common direct measure of linkage disequilibrium, both when there is no population substructure (F = 0) and when there is population substructure (F not = 0), for a single marker. The HWD test statistic gives rise to false positives caused by population stratification. These false positives can be controlled by adjusting the test statistic for the amount of variance inflation caused by the inbreeding coefficient (F). The power loss for the HWD test that arises when controlling for population structure is much less than that which arises for the common direct measure of linkage disequilibrium. However, in the multiplicative model, the HWD test has virtually no power even when allowing for non-zero F.

Virtual Design Method for Controlled Failure in Foldcore Sandwich Panels

NASA Astrophysics Data System (ADS)

Sturm, Ralf; Fischer, S.

2015-12-01

For certification, novel fuselage concepts have to prove equivalent crashworthiness standards compared to the existing metal reference design. Due to the brittle failure behaviour of CFRP this requirement can only be fulfilled by a controlled progressive crash kinematics. Experiments showed that the failure of a twin-walled fuselage panel can be controlled by a local modification of the core through-thickness compression strength. For folded cores the required change in core properties can be integrated by a modification of the fold pattern. However, the complexity of folded cores requires a virtual design methodology for tailoring the fold pattern according to all static and crash relevant requirements. In this context a foldcore micromodel simulation method is presented to identify the structural response of a twin-walled fuselage panels with folded core under crash relevant loading condition. The simulations showed that a high degree of correlation is required before simulation can replace expensive testing. In the presented studies, the necessary correlation quality could only be obtained by including imperfections of the core material in the micromodel simulation approach.

Virtual Reality Job Interview Training for Veterans with Posttraumatic Stress Disorder.

PubMed

Smith, Matthew J; Humm, Laura Boteler; Fleming, Michael F; Jordan, Neil; Wright, Michael A; Ginger, Emily J; Wright, Katherine; Olsen, Dale; Bell, Morris D

2015-01-01

Veterans with posttraumatic stress disorder (PTSD) have low employment rates and the job interview presents a critical barrier for them to obtain competitive employment. To evaluate the acceptability and efficacy of virtual reality job interview training (VR-JIT) among veterans with PTSD via a small randomized controlled trial (n=23 VR-JIT trainees, n=10 waitlist treatment-as-usual (TAU) controls). VR-JIT trainees completed up to 10 hours of simulated job interviews and reviewed information and tips about job interviewing, while wait-list TAU controls received services as usual. Primary outcome measures included two pre-test and two post-test video-recorded role-play interviews scored by blinded human resource experts and self-reported interviewing self-confidence. Trainees attended 95% of lab-based VR-JIT sessions and found the intervention easy-to-use, helpful, and prepared them for future interviews. VR-JIT trainees demonstrated significantly greater improvement on role-play interviews compared with wait-list TAU controls (p=0.04) and demonstrated a large effect for within-subject change (Cohen's d=0.76). VR-JIT performance scores increased significantly over time (R-Squared=0.76). Although VR-JIT trainees showed a moderate effect for within-subject change on self-confidence (Cohen's d=0.58), the observed difference between conditions did not reach significance (p=0.09). Results provide preliminary support that VR-JIT is acceptable to trainees and may be efficacious for improving job interview skills and self-confidence in veterans with PTSD.

Robust hopping based on virtual pendulum posture control.

PubMed

Sharbafi, Maziar A; Maufroy, Christophe; Ahmadabadi, Majid Nili; Yazdanpanah, Mohammad J; Seyfarth, Andre

2013-09-01

A new control approach to achieve robust hopping against perturbations in the sagittal plane is presented in this paper. In perturbed hopping, vertical body alignment has a significant role for stability. Our approach is based on the virtual pendulum concept, recently proposed, based on experimental findings in human and animal locomotion. In this concept, the ground reaction forces are pointed to a virtual support point, named virtual pivot point (VPP), during motion. This concept is employed in designing the controller to balance the trunk during the stance phase. New strategies for leg angle and length adjustment besides the virtual pendulum posture control are proposed as a unified controller. This method is investigated by applying it on an extension of the spring loaded inverted pendulum (SLIP) model. Trunk, leg mass and damping are added to the SLIP model in order to make the model more realistic. The stability is analyzed by Poincaré map analysis. With fixed VPP position, stability, disturbance rejection and moderate robustness are achieved, but with a low convergence speed. To improve the performance and attain higher robustness, an event-based control of the VPP position is introduced, using feedback of the system states at apexes. Discrete linear quartic regulator is used to design the feedback controller. Considerable enhancements with respect to stability, convergence speed and robustness against perturbations and parameter changes are achieved.

A training platform for many-dimensional prosthetic devices using a virtual reality environment

PubMed Central

Putrino, David; Wong, Yan T.; Weiss, Adam; Pesaran, Bijan

2014-01-01

Brain machine interfaces (BMIs) have the potential to assist in the rehabilitation of millions of patients worldwide. Despite recent advancements in BMI technology for the restoration of lost motor function, a training environment to restore full control of the anatomical segments of an upper limb extremity has not yet been presented. Here, we develop a virtual upper limb prosthesis with 27 independent dimensions, the anatomical dimensions of the human arm and hand, and deploy the virtual prosthesis as an avatar in a virtual reality environment (VRE) that can be controlled in real-time. The prosthesis avatar accepts kinematic control inputs that can be captured from movements of the arm and hand as well as neural control inputs derived from processed neural signals. We characterize the system performance under kinematic control using a commercially available motion capture system. We also present the performance under kinematic control achieved by two non-human primates (Macaca Mulatta) trained to use the prosthetic avatar to perform reaching and grasping tasks. This is the first virtual prosthetic device that is capable of emulating all the anatomical movements of a healthy upper limb in real-time. Since the system accepts both neural and kinematic inputs for a variety of many-dimensional skeletons, we propose it provides a customizable training platform for the acquisition of many-dimensional neural prosthetic control. PMID:24726625

Control of repulsive force in a virtual environment using an electrorheological haptic master for a surgical robot application

NASA Astrophysics Data System (ADS)

Oh, Jong-Seok; Choi, Seung-Hyun; Choi, Seung-Bok

2014-01-01

This paper presents control performances of a new type of four-degrees-of-freedom (4-DOF) haptic master that can be used for robot-assisted minimally invasive surgery (RMIS). By adopting a controllable electrorheological (ER) fluid, the function of the proposed master is realized as a haptic feedback as well as remote manipulation. In order to verify the efficacy of the proposed master and method, an experiment is conducted with deformable objects featuring human organs. Since the use of real human organs is difficult for control due to high cost and moral hazard, an excellent alternative method, the virtual reality environment, is used for control in this work. In order to embody a human organ in the virtual space, the experiment adopts a volumetric deformable object represented by a shape-retaining chain linked (S-chain) model which has salient properties such as fast and realistic deformation of elastic objects. In haptic architecture for RMIS, the desired torque/force and desired position originating from the object of the virtual slave and operator of the haptic master are transferred to each other. In order to achieve the desired torque/force trajectories, a sliding mode controller (SMC) which is known to be robust to uncertainties is designed and empirically implemented. Tracking control performances for various torque/force trajectories from the virtual slave are evaluated and presented in the time domain.