Collaborating in a complex environment. From bricks to bytes. Creating the virtual healthcare organization.
Explore the source record for details and available documents.
Delivery of Health Care, Integrated↗
SEARCH · PubMed Health
Results for “virtual environment”
Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Tele-Immersive medical educational environment.
By combining teleconferencing, tele-presence, and Virtual Reality, the Tele-Immersive environment enables master surgeons to teach residents in remote locations. The design and implementation of a Tele-Immersive medical educational environment, Teledu, is presented in this paper. Teledu defines a set of Tele-Immersive user interfaces for medical education. In addition, an Application Programming Interface (API) is provided so that developers can easily develop different applications with different requirements in this environment. With the help of this API, programmers only need to design a plug-in to load their application specific data set. The plug-in is an object-oriented data set loader. Methods for rendering, handling, and interacting with the data set for each application can be programmed in the plug-in. The environment has a teacher mode and a student mode. The teacher and the students can interact with the same medical models, point, gesture, converse, and see each other.
Computer Communication Networks↗
Learning and coding of concepts in neural networks.
Our environment consists of virtually an infinite number of scenarios in which we have to function. In order to respond properly to an incoming stimulus, the brain has first to analyze it, and to find out the basic familiar elements that are part of it. In other words, by using a library which contains a relatively small number of basic concepts, the brain analyzes the multitude of incoming events. Some of those basic concepts are innate, but many of them must be learned, in order to accommodate for the arbitrary environment around us. A classifying box is defined as the neural network that finds out the familiar concepts that are present in an incoming stimulus. Models for classifying boxes are introduced, and possible mechanisms by which they may establish their libraries of concepts are suggested, and then compared and evaluated by computer simulations.
Classification↗
Virtual reality-multimedia synthesis: next-generation learning environments for medical education.
The Learning Resources Center of the University of California, San Diego School of Medicine has begun to investigate the potential of virtual reality (VR) as a tool for medical education. We are currently integrating VR with communications, animation, and visualization technologies to form a hybrid learning and training environment. Our program development reflects a curriculum-based strategy with emphasis on instructional objectives and educational outcomes. Demonstrated need, feasibility of a technology-based solution, and appropriateness of resource allocation are primary considerations. As the VR world is built, comparative analyses are being made of control strategies, display options, and interface design.
Computer Simulation↗
Combined space-variant maps for optical-flow-based navigation.
A robot navigating in an unstructured environment needs to avoid obstacles in its way and determine free spaces through which it can safely pass. We present here a set of optical-flow-based behaviors that allow a robot moving on a ground plane to perform these tasks. The behaviors operate on a purposive representation of the environment called the "virtual corridor" which is computed as follows: the images captured by a forward-facing camera rigidly attached to the robot are first remapped using a space-variant transformation. Then, optical flow is computed from the remapped image stream. Finally, the virtual corridor is extracted from the optical flow by applying simple but robust statistics. The introduction of a space-variant image preprocessing stage is inspired by biological sensory processing, where the projection and remapping of a sensory input field onto higher-level cortical areas represents a central processing mechanism. Such transformations lead to a significant data reduction, making real-time execution possible. Additionally, they serve to "re-present" the sensory data in terms of ecologically relevant features, thereby simplifying the interpretation by subsequent processing stages. In accordance with these biological principles we have designed a space-variant image transformation, called the polar sector map, which is ideally suited to the navigational task. We have validated our design with simulations in synthetic environments and in experiments with real robots.
Animals↗
When ecology and sociology meet: the contributions of Edward A. Ross.
Edward A. Ross, a key figure in the early history of American sociology, developed a conceptualization of natural and social changes of the material environment that is virtually forgotten today. In this paper, these topics are discussed and located vis-à-vis Ross's intellectual contemporaries and their general take on the nature/society relationship. It is argued that ecological and sociological ideas in the early twentieth century influenced one another and, in the case of Ross, produced a perspective of social change that tried to include the dynamics of nature.
Ecology↗
Parlaying digital imaging and communications in medicine and open architecture to our advantage: the new Department of Defense picture archiving and communications system.
The Department of Defense (DoD) undertook a major systems specification, acquisition, and implementation project of multivendor picture archiving and communications system (PACS) and teleradiology systems during 1997 with deployment of the first systems in 1998. These systems differ from their DoD predecessor system in being multivendor in origin, specifying adherence to the developing Digital Imaging and Communications in Medicine (DICOM) 3.0 standard and all of its service classes, emphasizing open architecture, using personal computer (PC) and web-based image viewing access, having radiologic telepresence over large geographic areas as a primary focus of implementation, and requiring bidirectional interfacing with the DoD hospital information system (HIS). The benefits and advantages to the military health-care system accrue through the enabling of a seamless implementation of a virtual radiology operational environment throughout this vast healthcare organization providing efficient general and subspecialty radiologic interpretive and consultative services for our medical beneficiaries to any healthcare provider, anywhere and at any time of the night or day.
Computer Systems↗
Face-, expert, and referent validity of the Xitact LS500 laparoscopy simulator.
BACKGROUND: This study was undertaken to establish face-, expert, and referent validity of the Xitact LS500; a virtual reality laparoscopic cholecystectomy simulator. METHODS: A four-page, 20-item structured questionnaire was presented to 120 surgeons attending a surgical convention. Participants received an instructed hands-on "tour" on the Xitact simulator. Data were analyzed according to the level of experience of the surgeon, resulting in an "expert group opinion" of 87 surgeons and a "referent group opinion" of 33 surgeons. RESULTS: The majority of respondents believe Xitact has the potential to become a useful tool in teaching (93.1%) and measuring performance assessment (79.3%) in laparoscopic cholecystectomy. Expert- and referent-group opinion does not differ significantly on any of the presented statements. The opinion regarding the realism of the virtual laparoscopic cholecystectomy environment is favorable among both groups, although it is considered not yet perfect. The "haptic feedback" sensation of the Xitact is a parameter that needs further development. CONCLUSIONS: Both expert- and referent surgeons value Xitact to be an important and useful tool in the laparoscopic teaching setting. Further studies need to be performed to establish the construct validity of the simulator (e.g., to what extent is the simulator logically encompassed into a theoretical framework of acquiring skills, needed for the laparoscopic cholecystectomy) to measure shortening of learning curves on the laparoscopic cholecystectomy procedure, and ultimately to justify its use in the surgical curriculum.
Adult↗
Volume regulation and metabolism of suspended C6 glioma cells: an in vitro model to study cytotoxic brain edema.
The in vitro model presented provides an approach to study the nature of cell volume control as well as of swelling mechanisms under pathophysiological conditions. Pertinent parameters of cell volume control can be analyzed in isolation due to a virtually infinite extracellular environment precluding secondary effects of the suspended cells. Exposure of C6 glial cells to hypotonic medium was investigated as a model to study fundamental aspects of cell volume control. In confirmation of studies on other cell types glial cells suspended in hypotonic medium recover cell volume after transient swelling. Normalization of cell volume is associated with stimulation of respiration. Moreover, normalization of cell volume in hypotonic medium can be pharmacologically influenced. Addition of naftidrofuryl which enhances cellular O2-consumption led to acceleration of cell volume recovery. On the other hand, inhibition of Na+-K+-ATPase by ouabain did not prevent regulatory volume decrease ruling out a major role of the Na+-transport enzyme in this process. Contrary to hypotonic suspension, hypertonic exposure did not result in volume regulation during an observation period of 3 h. However, this may not necessarily exclude a capability of cell volume to normalize in hypertonic conditions as observed in vivo. Volume control of glial cells in abnormal osmotic medium may--on a cellular basis--reflect fundamental adaptive processes of central nervous tissue. Knowledge of the physiological and biochemical basis of cell volume control is not only of scientific interest but also of therapeutical significance in patients suffering from cytotoxic brain edema.
Brain Edema↗
Critical assessment of carcinogenic risk policy.
Fact. Cancer is a relatively common yet greatly feared disease. Belief. The concept that cancer is largely preventable is widely held by advocate groups, the press, and Congress. Belief. The concept that carcinogens at any level of exposure pose a significant cancer risk to human is widely believed by the public. Fact. In contrast to this belief, carcinogens are now known to be widespread in the environment and that virtually all substances are contaminated with carcinogens at some albiet low level. Fact. The solution to the ubiguitous presence of carcinogens cannot be solved by regulatory fiat. Fact. Often the only viable solution to regulating carcinogens is setting maximum levels of acceptable exposure (tolerances). Belief. In U.S. society, the process of establishing tolerances must be conducted in the open, providing adequate opportunity for public comment. Fact. The courts will sustain regulatory agency decisions about risks only if the administrative procedures used comply with the Administrative Procedures Act and if the technical methodology used is in good standing. Fact. For the method to be in good standing it cannot be a recent invention created after the fact to solve the issue at hand but must instead be a procedure that is claimed to be generally applicable to determining or estimating cancer risk. Belief. QRA should be an orderly procedure or process by which cancer risk estimations are conducted in an unbiased manner. As such it is fundamentally acceptable to the courts for resolving disputes. Fact. However, because QRA is dependent upon a large number of assumptions and because regulatory agencies feel compelled to act in a conservative, risk-adverse manner, risk estimates are often criticized for being over stated. Belief. To make risk estimates more realistic, data or facts must substitute for worst case assumptions. Fact. This process of substituting scientific facts for assumptions is occurring but it is expensive, time consuming, and not always possible. Nevertheless, it constitutes a major opportunity for improving the process by which risk estimates are made.
Animals↗
Rapid application design of an electronic clinical skills portfolio for undergraduate medical students.
The aim was to find how to use information and communication technology to present the clinical skills content of an undergraduate medical curriculum. Rapid application design was used to develop the product, and technical action research was used to evaluate the development process. A clinician-educator, two medical students, two computing science masters students, two other project workers, and a hospital education informatics lead, formed a design team. A sample of stakeholders took part in requirements planning workshops and continued to advise the team throughout the project. A university hospital had many features that favoured fast, inexpensive, and successful system development: a clearly defined and readily accessible user group; location of the development process close to end-users; fast, informal communication; leadership by highly motivated and senior end-users; devolved authority and lack of any rigidly imposed management structure; cooperation of clinicians because the project drew on their clinical expertise to achieve scholastic goals; a culture of learning and involvement of highly motivated students. A detailed specification was developed through storyboarding, use case diagramming, and evolutionary prototyping. A very usable working product was developed within weeks. "SkillsBase" is a database web application using Microsoft Active Server Pages, served from a Microsoft Windows 2000 Server operating system running Internet Information Server 5.0. Graphing functionality is provided by the KavaChart applet. It presents the skills curriculum, provides a password-protected portfolio function, and offers training materials. The curriculum can be presented in several different ways to help students reflect on their objectives and progress towards achieving them. The reflective portfolio function is entirely private to each student user and allows them to document their progress in attaining skills, as judged by self, peer and tutor assessment, and examinations. Training materials include web links and materials developed locally using pedagogic principles developed by the SkillsBase team. Although the usability of SkillsBase has been proven, uptake of software that has arisen 'bottom-up' from within the curriculum has proved slow. We plan to incorporate the SkillsBase services into a more comprehensive virtual managed learning environment, anticipating that presenting the functionality in an environment that is routinely used by students and teachers will increase uptake and use.
Clinical Competence↗
VRDD: applying virtual reality visualization to protein docking and design.
We have developed an interactive docking program called VRDD. It offers various modes of displaying molecules in an immersive, three-dimensional virtual reality (VR) environment. It allows a user to interactively perform molecular docking aided by automatic docking and side chain conformational search. Binding free energies are computed in real time, and the program enables the user to explore only clash-free orientations of a ligand. VRDD also supplies visual and auditory feedback during docking and side chain search, indicating the levels of atomic overlap and interaction energy. The stunning VR graphics immerse users in the scene and can maximally stimulate their design intuition. We have tested VRDD on three cases with increasing complexity: a nine-residue-long peptide bound to a major histocompatibility complex (MHC) molecule, barstar bound to barnase, and an antibody bound to a hemagglutinin. Without prior knowledge, combinations of hand-docking and automatic refinement led to accurate complex structures for the first two complexes. The third case, for which all automatic docking algorithms failed to identify the correct complex in a previous blind test, also failed for VRDD. Our results show that the combination of VR docking and automatic docking can make unique contributions to molecular modeling.
Antibodies↗
Design and development of computer-aided chemical systems: representation and balance of inorganic chemical reactions
A model for the tracking of inorganic chemical reactions is proposed. Designed to acquire, process, and solve a great number of inorganic reactions, this model will hopefully contribute to the development of powerful computer-aided chemistry teaching systems for use within or without the environment of a virtual laboratory. Using full representation of an inorganic reaction to allow the extraction of chemical knowledge, incomplete reactions (where species are absent) may be completed by adding the necessary species, and reactions may be solved and balanced. Various types of reaction are classified, and a layer-based model is defined for the solution of different reaction types, establishing the basis for the construction of a system which, based on a wide set of production rules, is capable of solving an incomplete inorganic chemical reaction.
Journal Article↗
X-ray absorption spectroscopy of chloroperoxidase compound I: Insight into the reactive intermediate of P450 chemistry.
We report the structural characterization of a thiolate-ligated ferryl radical. Using x-ray absorption spectroscopy, we examined chloroperoxidase (CPO) compound I (CPO-I). Our results indicate that CPO-I is an authentic ferryl species with an Fe-O bond of 1.65 A. Axial-ligand interactions result in a remarkably long 2.48-A Fe-S bond. Analogous forms of cytochrome P450 and CPO have been shown to possess virtually identical coordination environments. Thus, it seems likely that our findings provide a good structural description of the elusive P450-I.
Chloride Peroxidase↗
Computer mouse use and cumulative trauma disorders of the upper extremities.
The computer mouse is now present in virtually every office environment because of the recent adoption of the graphical user interface. However, Karlqvist et al. (1994) pointed out that there still remains a paucity of work on the musculoskeletal problems associated specifically with computer mouse use. Likewise, there have been no published data on the magnitude of upper extremity musculoskeletal disorders associated with computer mouse use. In order to ascertain this magnitude, claims data from the Liberty Mutual Group were reviewed for the years 1986 to 1993, inclusive. Count, total cost and average cost per claim for all claims associated with computer use and computer mouse use were determined for the years in question. It was concluded that although there are few claims related to computer mouse use, it appears to be a growing problem, and therefore, perhaps, deserves more research and intervention attention. However, the present magnitude is less than for other musculoskeletal disorders.
Arm↗
Efficacy of stereoscopic visualization and six degrees of freedom interaction in preoperative planning of total hip replacement.
The aim of this study was to assess the accuracy of a six-degrees-of-freedom application for pre-operative planning of total hip replacement in a virtual reality (VR) environment. A test was performed estimating the system inherent accuracy. The users can move objects in the VR environment with an intrinsic accuracy almost four orders of magnitude greater than the object dimension. A second unambiguous and relevant task was defined to assess the accuracy achievable with the interface in a specific planning task. The results were compared with those obtained with 2D interfaces for both the stem and the cup component. The RMSE was assumed as an indicator of the achievable accuracy. The accuracy of the immersive interface was comparable with that achievable with a standard mouse - monitor interface. The users were consistent using the VR interface, confirming the high usability of the new interface and the steep learning curve of users unfamiliar with the new environment. This study has demonstrated that the application of VR environment for pre-operative planning of total hip replacement may help to shorten the duration of the positioning and to yield consistent results even with first-time users.
Arthroplasty, Replacement, Hip↗
4D bioinformatics: a new look at the ribosome as an example.
We have adapted the Java Molecular Viewer (JMV) to virtual reality display environments, through a number of extensions to the Java 3D code. Phylogenetic information derived from multiple alignments (temporal information) can be overlaid onto molecule structures (spatial information). The number of sequences included in the underlying multiple alignment can be changed instantaneously, resulting in dynamical updates of the displayed information. JMV was also extended to handle an infinite number of objects (molecules) in the same display. The objects can be manipulated in six degrees of freedom simultaneously or independently. We have used the small subunit ribosomal RNA to demonstrate the system (http:// cave.ucalgary.ca), which can be used for any molecule with a resolved structure.
Animals↗
Application of virtual reality graphics in assessment of concussion.
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.
Adolescent↗