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At least 883 records · Page 49Linked to original sources

PubMed2000

Optic flow helps humans learn to navigate through synthetic environments.

Self-movement through an environment generates optic flow, a potential source of heading information. But it is not certain that optic flow is sufficient to support navigation, particularly navigation along complex, multi-legged paths. To address this question, we studied human participants who navigated synthetic environments with and without salient optic flow. Participants used a keyboard to control realistic simulation of self-movement through computer-rendered, synthetic environments. Because these environments comprised series of identically textured virtual corridors and intersections, participants had to build up some mental representation of the environment in order to perform. The impact of optic flow on learning was examined in two experiments. In experiment 1, participants learned to navigate multiple T-junction mazes with and without accompanying optic flow. Optic flow promoted faster learning, mainly by preventing disorientation and backtracking in the maze. In experiment 2, participants found their way around a virtual city-block environment, experiencing two different kinds of optic flow as they went. By varying the rate at which the display was updated, we created optic flow that was either fluid or choppy. Here, fluid optic flow (as compared with choppy optic flow) enabled participants to locate a remembered target position more accurately. When other cues are unavailable, optic flow can be a significant aid in wayfinding. Among other things, optic flow can facilitate path integration, which involves updating a mental representation of place by combining the trajectories of previously travelled paths [corrected].

Adolescent↗

PubMed2006

Nurses' perception of single-occupancy versus multioccupancy rooms in acute care environments: an exploratory comparative assessment.

Health care design professionals, planners, and administrators cite the advantages of private patient rooms, including reduction of hospital-acquired infections, reduction of patient stress levels, and facilitation of nurses' and health care workers' efficiency [e.g., Ulrich, R. (2003). Creating a healing environment with evidence-based design. Paper presented at the American Institute of Architects, Academy of Architecture for Health virtual seminar-Healing environments; Ulrich, R., Quan, X., Zimring, C., Joseph, A., & Choudhary, R. (2004). The role of the physical environment in the hospital of the 21st century: A once-in-a-lifetime-opportunity. ]. A review of the literature revealed that operating costs are reduced in single-patient rooms compared with multioccupancy rooms due to reduction in transfer cost, higher bed occupancy rates, and reduction in labor cost. In addition, single rooms can positively impact patients' hospital experience through increased privacy, better interaction between family and staff, and reduced noise and anxiety. This pilot study focused on nurses' perception of the advantages and disadvantages of single-occupancy versus multioccupancy patient rooms in medical-surgical units in four hospitals in the northwest. A majority of respondents in the four hospitals favored single rooms over double-occupancy rooms for the majority of the 15 categories, including the following: appropriateness for patient examination, interaction with or accommodation of family members, and lower probability of dietary mix-ups. Future studies need to carefully examine the objective measures of patient care variables (e.g., incidents of medication errors, opportunities for surveillance), patient outcomes (e.g., recovery rate, falls), and implications of room occupancy on operating costs.

Acute Disease↗

PubMed1999

Presence as an emotional experience.

Presence or the sense of "being there" has been discussed in the literature as an essential, defining aspect of Virtual Reality (VR). The VR literature includes definitions rooted in behavioral response, signal detection theory, and philosophy, but has generally ignored the emotional aspects of experience. The purpose of this paper is to reexamine the concept of presence in terms of people's emotional engagement with reality and their environment. Emotions are an essential part of how people experience the world. Any theory of presence must take emotional factors into account. This thesis has implications about how research should be conducted to further our understanding of presence. Validated psychological techniques for assessing emotions by subjective report, behavioral observations, and facial analysis can all be applied to increase our understanding of virtual presence. Further understanding of the interaction between presence and emotional state will improve our understanding of the construct of presence as well as better inform us about how virtual environments can be applied in creating emotional effects or treating emotional disorders.

Emotions↗

PubMed2003

Secure environment for real-time tele-collaboration on virtual simulation of radiation treatment planning.

A secure framework is described for real-time tele-collaboration on Virtual Simulation procedure of Radiation Treatment Planning. An integrated approach is followed clustering the security issues faced by the system into organizational issues, security issues over the LAN and security issues over the LAN-to-LAN connection. The design and the implementation of the security services are performed according to the identified security requirements, along with the need for real time communication between the collaborating health care professionals. A detailed description of the implementation is given, presenting a solution, which can directly be tailored to other tele-collaboration services in the field of health care. The pilot study of the proposed security components proves the feasibility of the secure environment, and the consistency with the high performance demands of the application.

Computer Graphics↗

PubMedDate not supplied

[Use of hypertext as information and training tools in the prevention of occupational risk].

Modern medical education is based on a variety of teaching techniques, by means of which individuals learn most effectively. The availability of the new technologies together with the diffusion of personal computers is favouring the spreading of the use of hypertexts through the World Wide Web. This contribution describes 2 hypertexts ("Human Activities and Health Risk"; "Occupation, Risk and Disease. A Problem-Oriented Hypertext-Tool to Learn Occupational Medicine") and the prototype "Virtual Hospital". Assuming that prevention of health risks is based upon their knowledge, they have been created with the aim of providing users with problem-oriented tools, whose retorical aspects (content, information organization, user interface) are analysed. The "Human Activities and Health Risk" deals with the description of working activities and allows user to recognize health risks. The "Occupation, Risk and Disease. A Problem-Oriented Hypertext-Tool to Learn Occupational Medicine" embodies a case report containing the clustered information about the patient and the library including educational material (risk factors, symptoms and signs, organ system diseases, jobs, occupational risk factors, environment related diseases. The "Virtual Hospital" has been conceived assuming that an appropriate information can change workers' behaviour in hospital, where health risks can be often underevaluated. It consists of a variety of structured and unstructured information, which can be browsed by users, allowing the discovery of links and providing the awareness of the semantic relationship between related information elements (including environment, instruments, drugs, job analysis, situations at risk for health, preventive means). The "Virtual Hospital" aims making the understanding of the working situations at risk easier and more interesting, stimulating the awareness of the relationship between jobs and risks.

Computer-Assisted Instruction↗

PubMed2003

Virtual reality surgery: neurosurgery and the contemporary landscape.

OBJECTIVE: Virtual reality-simulated environments have been used for the training of personnel, most notably for military applications, for more than 35 years. The advantages conferred by being able to train novice personnel in a low- to no-risk simulated environment have long been appreciated by the medical community. The recent availability of affordable gigahertz-range microprocessors (once the exclusive domain of the Cray supercomputer) has made photorealistic graphical rendering and manipulation of virtual surgical substrates a reality. Concomitant advances in artificial intelligence systems and the portability of patient-specific magnetic resonance imaging, computed tomographic scanning, and angiographic image data presage the emergence of the surgical simulator as a modern surgical training adjunct. An overview of the status of surgical simulation with regard to its adaptability to current surgical training regimens is presented. METHODS: Extensive MEDLINE, Internet, and other database searches spanning the years 1960 to 2002 were conducted in an effort to delineate the status of simulated surgical environments. RESULTS: As would be expected, most articles addressing surgical simulation as their primary focus have been published in the past decade. A review of this literature demonstrates the broadest application in the field of endoscopic (and laparoscopic) procedures, most likely as a result of the reduced engineering burden with respect to incorporation of a haptic interface. CONCLUSION: The realization of ergonomically acceptable haptic interfaces remains elusive. Improvements in graphical rendering and the incorporation of artificial intelligence functions signal the certain emergence of surgical simulators as a viable supplement to the Halstedian method of surgical training.

Humans↗

PubMed1996

Brief report: two case studies using virtual reality as a learning tool for autistic children.

The children complied with most requests. Some of our teaching goals were limited by technology or space while others were limited by the difficulty of presenting a task to the children in a way that was understandable within their environment. However, the opportunity to introduce this technology to children was an important first step in exploring the potential VR offers to understanding the perceptual processes involved in autism. Our results indicate that the will accept a VR helmet and wear it, identify familiar objects and qualities of these objects in their environment while using the helmet, and locate and move toward objects in their environment while wearing the helmet. More research is necessary to verify the potential in this area, especially to discover if learning experiences through VR generalize to other environments, but it appears virtual reality may provide a useful tool for furthering our understanding of autism and guiding efforts at treatment and intervention.

Autistic Disorder↗

PubMed2000

Virtual reality in telemedicine.

Virtual reality (VR) can be considered as the leading edge of a general evolution of present communication interfaces involving the television, computer, and telephone. The main characteristic of this evolution is the full immersion of the human sensorimotor channels into a vivid and global communication experience. Because telemedicine principally focuses on transmitting medical information, VR has the potential to enhance this function. Particularly, VR can be used in telemedicine as an advanced communication interface, which enables a more intuitive mode of interacting with information, and as a flexible environment that enhances the feeling of physical presence during the interaction. In this article, the state of the art in VR-based telemedicine applications is described. This technology is now used in remote or augmented surgery as well as surgical training, which are critically dependent on eye-hand coordination. Recently, however, different researchers have tried to use virtual environments in medical visualization and for assessment and rehabilitation in neuropsychology. This article also discusses technological, ergonomical, and human factor issues, and specific guidelines are presented for expanding the use of VR in telemedicine.

Ergonomics↗

PubMed2000

3D dynamic body surface sensing and CT-body matching: a tool for patient set-up and monitoring in radiotherapy.

Recent advances in radical broad-beam conformal radiotherapy for disease at non-rigid sites suggest that the treatment room set-up of patients should be performed using the CT-plan digital body surface as a reference standard. In effect, the CT-plan surface is a "virtual shell" and should be used as such. To do this requires 3D body surface information to be captured live in the treatment room and then manipulated for comparison with the CT virtual shell. To address this situation, a near real-time prototype opto-electronic dynamic 3D surface sensor has been developed and equipped with a novel software utility for visualizing and matching the disparate surfaces arising from planning and treatment environments. Using the CT virtual shell and height-maps produced by the sensor, a two-phase 3D positioning strategy for patient set-up and monitoring is described. Phase one is an image-guided manual "approach". Phase two is automated "docking" using simulated annealing to determine optimum set-up corrections. The concepts and implementation are illustrated using archival patient data and an anthropomorphic phantom "patient" in a treatment room environment.

Humans↗

PubMed2003

Trauma team training in a distributed virtual emergency room.

A distributed simulation environment for training and evaluation of medical trauma teams is presented. Connected through the Internet, the geographically remote team members can communicate and interact using the clinically realistic environment provided by the MATADOR simulator. The scenario demonstrates an injured person's arrival at the hospital, and the diagnostic and therapeutic challenges that must be met in order to stabilize the virtual patient. Experiences from a field trial indicate that the simulator is useful both for professionals and medical students.

Computer Simulation↗

PubMed1999

An approach for access differentiation design in medical distributed applications built on databases.

A formalized "top to bottom" design approach was described in [1] for distributed applications built on databases, which were considered as a medium between virtual and real user environments for a specific medical application. Merging different components within a unified distributed application posits new essential problems for software. Particularly protection tools, which are sufficient separately, become deficient during the integration due to specific additional links and relationships not considered formerly. E.g., it is impossible to protect a shared object in the virtual operating room using only DBMS protection tools, if the object is stored as a record in DB tables. The solution of the problem should be found only within the more general application framework. Appropriate tools are absent or unavailable. The present paper suggests a detailed outline of a design and testing toolset for access differentiation systems (ADS) in distributed medical applications which use databases. The appropriate formal model as well as tools for its mapping to a DMBS are suggested. Remote users connected via global networks are considered too.

Computer Communication Networks↗

PubMed2004

Wireless local area network in a prehospital environment.

BACKGROUND: Wireless local area networks (WLANs) are considered the next generation of clinical data network. They open the possibility for capturing clinical data in a prehospital setting (e.g., a patient's home) using various devices, such as personal digital assistants, laptops, digital electrocardiogram (EKG) machines, and even cellular phones, and transmitting the captured data to a physician or hospital. The transmission rate is crucial to the applicability of the technology in the prehospital setting. METHODS: We created two separate WLANs to simulate a virtual local are network environment such as in a patient's home or an emergency room (ER). The effects of different methods of data transmission, number of clients, and roaming among different access points on the file transfer rate were determined. RESULTS: The present results suggest that it is feasible to transfer small files such as patient demographics and EKG data from the patient's home to the ER at a reasonable speed. Encryption, user control, and access control were implemented and results discussed. CONCLUSIONS: Implementing a WLAN in a centrally managed and multiple-layer-controlled access control server is the key to ensuring its security and accessibility. Future studies should focus on product capacity, speed, compatibility, interoperability, and security management.

Cell Phone↗

PubMed1996

Raman spectroscopy of the Ff gene V protein and complexes with poly(dA): nonspecific DNA recognition and binding.

Raman spectra of crystals and solutions of the single-stranded DNA binding protein of bacteriophage Ff (gene V protein, gVp) and of solution complexes of gVp with single-stranded poly-(deoxyadenylic acid) [poly(dA)] reveal the following: (i) The gVp secondary and tertiary structures are similar in solution and in the crystal and are dominated by beta-sheet domains, in agreement with NMR and X-ray findings. (ii) Subunit conformation and side chain environments of gVp are virtually unchanged over a wide range of salt concentration (0 < [NaCl] < 100 mM); however, the solution conformation of poly(dA) exhibits sensitivity to added salt. The perturbed Raman markers indicate subtle changes in helix backbone geometry with accompanying small differences in base stacking as the concentration of NaCl is changed. (iii) In complexes with poly(dA), neither the conformation of gVp nor its side chain environments are altered significantly in comparison to the free protein. This is the case at both high salt (nucleotide-to-subunit binding stoichiometry n = 4) and low salt (n = 3). (iv) The Raman signature of poly(dA) undergoes small perturbations upon gVp binding, indicative of small changes in base stacking and phosphodiester backbone conformation. The present results show that the different stoichiometric binding modes of gVp to poly(dA) are accomplished without significant changes in gVp subunit structure and with only modest changes in the single-stranded poly(dA) ligand. This contrasts sharply with sequence-specific double-stranded DNA binding proteins, such as the phage lambda and D108 repressors, which undergo substantial structural changes upon DNA binding, and which also alter more dramatically the Raman fingerprints of their DNA target sites. Thus, nonspecific and specific nucleic acid recognition modes are distinguishable by Raman spectroscopy. The Raman signature of gVp also allows examination of hydrogen bonding interactions of unique side chains within the hydrophobic core (cysteine 33) and at the binding interface (tyrosine 41). These are discussed in relation to the recently published gVp crystal structure.

Amino Acid Sequence↗

PubMed2000

Radiological tele-immersion for next generation networks.

Since the acquisition of high-resolution three-dimensional patient images has become widespread, medical volumetric datasets (CT or MR) larger than 100 MB and encompassing more than 250 slices are common. It is important to make this patient-specific data quickly available and usable to many specialists at different geographical sites. Web-based systems have been developed to provide volume or surface rendering of medical data over networks with low fidelity, but these cannot adequately handle stereoscopic visualization or huge datasets. State-of-the-art virtual reality techniques and high speed networks have made it possible to create an environment for clinicians geographically distributed to immersively share these massive datasets in real-time. An object-oriented method for instantaneously importing medical volumetric data into Tele-Immersive environments has been developed at the Virtual Reality in Medicine Laboratory (VRMedLab) at the University of Illinois at Chicago (UIC). This networked-VR setup is based on LIMBO, an application framework or template that provides the basic capabilities of Tele-Immersion. We have developed a modular general purpose Tele-Immersion program that automatically combines 3D medical data with the methods for handling the data. For this purpose a DICOM loader for IRIS Performer has been developed. The loader was designed for SGI machines as a shared object, which is executed at LIMBO's runtime. The loader loads not only the selected DICOM dataset, but also methods for rendering, handling, and interacting with the data, bringing networked, real-time, stereoscopic interaction with radiological data to reality. Collaborative, interactive methods currently implemented in the loader include cutting planes and windowing. The Tele-Immersive environment has been tested on the UIC campus over an ATM network. We tested the environment with 3 nodes; one ImmersaDesk at the VRMedLab, one CAVE at the Electronic Visualization Laboratory (EVL) on east campus, and a CT scan machine in UIC Hospital. CT data was pulled directly from the scan machine to the Tele-Immersion server in our Laboratory, and then the data was synchronously distributed by our Onyx2 Rack server to all the VR setups. Instead of permitting medical volume visualization at one VR device, by combining teleconferencing, tele-presence, and virtual reality, the Tele-Immersive environment will enable geographically distributed clinicians to intuitively interact with the same medical volumetric models, point, gesture, converse, and see each other. This environment will bring together clinicians at different geographic locations to participate in Tele-Immersive consultation and collaboration.

Humans↗

PubMed2000

Creating a human phantom for the virtual human program.

A high-resolution human phantom--a computer representation of the human anatomy--is needed as part of the Virtual Human (VH) simulation environment being developed by Oak Ridge National Laboratory and collaborators. Within the VH environment, this 3D anatomical phantom is coupled with physiological models and data to investigate a wide range of human biological and physical responses to stimuli. This paper describes how the phantom was created using the Visible Human (male) image data from the U.S. National Library of Medicine. Initially, X-ray computed tomography (CT) as well as photographic images of the Visible Human (male) torso were segmented and classified with software developed using IDL. From these data, non-uniform, rational B-spline (NURBS) spatial models were fitted to represent the surfaces of discrete body structures such as bones and organs. This collection of NURBS models, referred to as the NURBS VH, defines the fundamental Virtual Human phantom. The NURBS VH is compatible with modeling and animation software, enabling dynamic manipulation of body structures and their associated visual representations. The organization of the structural data lends itself to existing and evolving Web and electronic communication standards, making it attractive for applications such as medical training. In addition, finite-element (FE) meshes were created from the NURBS VH for use in trauma simulation, electromagnetic field exposure modeling, dosimetry, and other applications requiring spatially-defined tissue properties. The ability to scale the NURBS VH to account for age and size and the ability to easily animate NURBS objects yield a very flexible human phantom for the VH simulation environment.

Anatomy, Cross-Sectional↗

PubMed2006

Can design principles of traditional learning theories be fulfilled by computer-based training systems in medicine: the example of CAMPUS.

PURPOSE: Computer-based training (CBT) systems offer the potential to efficiently support modern teaching and learning. However, it is still unknown if a similar efficient learning experience built on sound learning theories and corresponding design principles can be created in the complex health care environment. The purpose of this paper is to analyse to what extent learning theories and corresponding design principles are relevant and can successfully be applied in computer-based training in medicine. METHODS: We use the case-based CBT system CAMPUS as an example for a CBT system currently used to enhance the medical teaching and learning experience. We apply two well-accepted learning theories (Bloom's taxonomy and practice fields) and related design principles to determine to what extent they are relevant and fulfilled in the context of CAMPUS. RESULTS: We demonstrate that in principle these learning theories and design principles can be implemented using computer-based training. However, not all design principles can be fulfilled by the system alone; rather the integration of the system into adequate -- traditional or virtual -- teaching and learning environments is essential. CONCLUSIONS: Traditional learning theories and design principles are a valuable means in designing adequate CBT systems in medicine. They can be successfully implemented in CBT systems for medical education if the system itself is adequately integrated into teaching and learning environments.

Computer-Assisted Instruction↗

PubMed2003

Exploring the use of computer games and virtual reality in exposure therapy for fear of driving following a motor vehicle accident.

Specific phobia, situational type-driving, induced by accident (accident phobia) occurs in 18-38% of those involved in a vehicular accident of sufficient severity to warrant referral to the emergency departments of a general hospital. The objective is to investigate, in an open study, the effectiveness of the combined use of computer generated environments involving driving games (game reality [GR]) and a virtual reality (VR) driving environment in exposure therapy for the treatment of driving phobia following a motor vehicle accident (MVA) program. Fourteen subjects who met DSM-IV criteria for Simple Phobia/Accident Phobia and were referred from the emergency department of a general hospital were exposed to a Virtual Driving Environment (Hanyang University Driving Phobia Environment) and computer driving games (London Racer/Midtown Madness/Rally Championship). Patients who experienced "immersion" (i.e., a sense of presence with heightened anxiety) in one of the driving simulations (defined as an increase in SUD ratings of 3 and/or an increase of heart rate > 15 BPM in a 1-h trial session of computer simulation driving) were exposed to a cognitive behavioral program of up to 12 1-h sessions involving graded driving simulation tasks with self-monitoring, physiological feedback, diaphragmatic breathing and cognitive reappraisal. Subjects were assessed at the beginning and end of therapy with measurements of: physiological responsivity (heart rate), subjective ratings of distress (SUD), rating scales for severity of fear of driving (FDI), Posttraumatic Stress Disorder (CAPS) and depression (HAM-D) and achievement of target behaviors. Of all patients 7/14 (50%) became immersed in the driving environments. This immersed group (n = 7) completed the exposure program. Pre- and post-treatment comparisons showed significant post treatment reductions on all measures SUDS (p = 0.008), FDI (p = 0.008), CAPS (p = 0.008), HR (p = 0.008), CAPS (p = 0.008), HAM-D (p = 0.031). Further analysis of the FDI showed significant reductions in all three subscales: travel distress (p = 0.008), travel avoidance (p = 0.008), and maladaptive driving strategies (p = 0.016). The findings of this study suggest that VR and GR may have a useful role in the treatment of driving phobia post-accident even when co-morbid conditions such as post-traumatic stress disorder and depression are present.

Accidents, Traffic↗

PubMed2006

Development and application of in vivo expression technology (IVET) for analysing microbial gene expression in complex environments.

Establishing the mechanisms by which microbes interact with their environment, including eukaryotic hosts, is a major challenge that is essential for the economic utilisation of microbes and their products. Techniques for determining global gene expression profiles of microbes, such as microarray analyses, are often hampered by methodological restraints, particularly the recovery of bacterial transcripts (RNA) from complex mixtures and rapid degradation of RNA. A pioneering technology that avoids this problem is In Vivo Expression Technology (IVET). IVET is a 'promoter-trapping' methodology that can be used to capture nearly all bacterial promoters (genes) upregulated during a microbe-environment interaction. IVET is especially useful because there is virtually no limit to the type of environment used (examples to date include soil, oomycete, a host plant or animal) to select for active microbial promoters. Furthermore, IVET provides a powerful method to identify genes that are often overlooked during genomic annotation, and has proven to be a flexible technology that can provide even more information than identification of gene expression profiles. A derivative of IVET, termed resolvase-IVET (RIVET), can be used to provide spatio-temporal information about environment-specific gene expression. More recently, niche-specific genes captured during an IVET screen have been exploited to identify the regulatory mechanisms controlling their expression. Overall, IVET and its various spin-offs have proven to be a valuable and robust set of tools for analysing microbial gene expression in complex environments and providing new targets for biotechnological development.

Anti-Bacterial Agents↗