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At least 973 records · Page 54Linked to original sources

PubMed2003

A virtual reality system for the assessment and rehabilitation of the activities of daily living.

Successful rehabilitation with respect to the activities of daily living (ADL) requires accurate and effective assessment and training. A number of studies have emphasized the requirement for rehabilitation methods that are both relevant to the patient's real world environment, and that can also be transferred to other daily living tasks. Virtual reality (VR) has many advantages over other ADL rehabilitation techniques, and offers the potential to develop a human performance testing and training environment. Therefore, in this study, the virtual supermarket was developed and the possibility of using a VR system to assess and train cognitive ability in ADL investigated. This study demonstrates that VR technology offers great promise in the field of ADL training.

Activities of Daily Living↗

PubMed2001

Virtual eye muscle surgery based upon biomechanical models.

Within our research project "SEE-KID", a Software Engineering Environment for Knowledge-based Interactive Eye Motility Diagnostics, we focus on virtual reality training for the surgery of human eye muscles of--mostly--children age 1 to 3. Our report gives details on the sound integration of biomechanical muscle data into our virtual reality models in order to evaluate the quality of specific techniques for eye motility surgery regarding real-world pathologies. We illustrate the usefulness of our software system describing some of the possible medical applications, like optimized transposition surgery of the musculus obliquus superior.

Artificial Intelligence↗

PubMed2006

Improving the accuracy of the diagnosis of schizophrenia by means of virtual reality.

OBJECTIVE: The authors' goal was to improve the diagnosis of schizophrenia by using virtual reality technology to build a complex, multimodal environment in which cognitive functions can be studied (and measured) in parallel. METHOD: The authors studied sensory integration within working memory by means of computer navigation through a virtual maze. The simulated journey consisted of a series of rooms, each of which included three doors. Each door was characterized by three features (color, shape, and sound), and a single combination of features--the door-opening rule--was correct. Subjects had to learn the rule and use it. The participants were 39 schizophrenic patients and 21 healthy comparison subjects. RESULTS: Upon completion, each subject was assigned a performance profile, including various error scores, response time, navigation ability, and strategy. A classification procedure based on the subjects' performance profile correctly predicted 85% of the schizophrenic patients (and all of the comparison subjects). Several performance variables showed significant correlations with scores on a standard diagnostic measure (Positive and Negative Syndrome Scale), suggesting potential use of these measurements for the diagnosis of schizophrenia. On the other hand, the patients did not show unusual repetition of response despite stimulus cessation (called "perseveration" in classical studies of schizophrenia), which is a common symptom of the disease. This deficit appeared only when the subjects did not receive proper explanation of the task. CONCLUSIONS: The ability to study multimodal performance simultaneously by using virtual reality technology opens new possibilities for the diagnosis of schizophrenia with objective procedures.

Adult↗

PubMed1984

Comparative effects of germfree and ambient environments on the development of cystic kidney disease in CFWwd mice.

A spontaneously occurring murine renal cystic disease that resembles human adult-onset polycystic renal disease is described. The disease that develops in CFWwd mice is characterized by multiple bilateral cysts in the kidneys in all affected animals and hepatic cysts in approximately 20% of these animals with disease. Occasional thoracic aortic aneurysms were also observed in animals with cystic disease. The prevalence of the disease appears to be determined by the degree of exposure to the ambient environment. A germfree colony of CFWwd mice only rarely displayed the disease, whereas virtually 100% of animals housed for their entire life in the ambient environment died with the disease. Germfree mice removed from the axenic environment and placed in the ambient environment developed the disease, but at a lower prevalence than those animals born and reared in the ambient environment. Disease prevalence in animals reared in environmentally protected caging was between that in germfree and conventional animals. Genetic studies of AKR mice indicated that the disease is inherited in an autosomal dominant fashion but with reduced penetrance.

Animals↗

PubMed1994

Augmenting reality in rehabilitation medicine.

Virtual reality comprises the computer-based generation of realistic three-dimensional visual, auditory, and tactile environments in which a user can explore and interact with virtual objects. Although traditionally used for input devices to virtual worlds, the instrumented glove and sensor technologies of virtual reality may provide a dramatic new method for the measurement and amplification of human motion. This paper discusses some potential uses of virtual reality technology to support and augment routine activities for people who have physical disabilities. We present two different but related applications of this technology.

Computer Graphics↗

PubMed1995

[Computer-assisted intraoperative visualization of dental implants. Augmented reality in medicine].

In this paper, a recently developed computer-based dental implant positioning system with an image-to-tissue interface is presented. On a computer monitor or in a head-up display, planned implant positions and the implant drill are graphically superimposed on the patient's anatomy. Electromagnetic 3D sensors track all skull and jaw movements; their signal feedback to the workstation induces permanent real-time updating of the virtual graphics' position. An experimental study and a clinical case demonstrates the concept of the augmented reality environment--the physician can see the operating field and superimposed virtual structures, such as dental implants and surgical instruments, without loosing visual control of the operating field. Therefore, the operation system allows visualization of CT planned implantposition and the implementation of important anatomical structures. The presented method for the first time links preoperatively acquired radiologic data, planned implant location and intraoperative navigation assistance for orthotopic positioning of dental implants.

Computer Graphics↗

PubMed2005

An OGSA Middleware for managing medical images using ontologies.

This article presents a Middleware based on Grid Technologies that addresses the problem of sharing, transferring and processing DICOM medical images in a distributed environment using an ontological schema to create virtual communities and to define common targets. It defines a distributed storage that builds-up virtual repositories integrating different individual image repositories providing global searching, progressive transmission, automatic encryption and pseudo-anonimisation and a link to remote processing services. Users from a Virtual Organisation can share the cases that are relevant for their communities or research areas, epidemiological studies or even deeper analysis of complex individual cases. Software architecture has been defined for solving the problems that has been exposed before. Briefly, the architecture comprises five layers (from the more physical layer to the more logical layer) based in Grid Technologies. The lowest level layers (Core Middleware Layer and Server Services sc layer) are composed of Grid Services that implement the global managing of resources. The Middleware Components Layer provides a transparent view of the Grid environment and it has been the main objective of this work. Finally, the highest layer (the Application Layer) comprises the applications, and a simple application has been implemented for testing the components developed in the Components Middleware Layer. Other side-results of this work are the services developed in the Middleware Components Layer for managing DICOM images, creating virtual DICOM storages, progressive transmission, automatic encryption and pseudo-anonimisation depending on the ontologies. Other results, such as the Grid Services developed in the lowest layers, are also described in this article. Finally a brief performance analysis and several snapshots from the applications developed are shown. The performance analysis proves that the components developed in this work provide image processing applications with new possibilities for large-scale sharing, management and processing of DICOM images. The results show that the components fulfil the objectives proposed. The extensibility of the system is achieved by the use of open methods and protocols, so new components can be easily added.

Computer Communication Networks↗

PubMed2005

Human responses to augmented virtual scaffolding models.

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.

Adult↗

PubMedDate not supplied

The parahippocampus subserves topographical learning in man.

The hippocampus has been proposed as the site of neural representation of large-scale environmental space, based upon the identification of place cells (neurons with receptive fields for current position in the environment) within the rat hippocampus and the demonstration that hippocampal lesions impair place learning in the rat. The inability to identify place cells within the monkey hippocampus and the observation that unilateral hippocampal lesions do not selectively impair topographic behavior in humans suggest that alternate regions may subserve this function in man. To examine the contribution of the hippocampus and adjacent medial-temporal lobe structures to topographic learning in the human, a 'virtual' maze was used as a task environment during functional magnetic resonance imaging studies. During the learning and recall of topographic information, medial-temporal activity was confined to the para- hippocampal gyri. This activity accords well with the lesion site known to produce topographical disorientation in humans. Activity was also observed in cortical areas known to project to the parahippocampus and previously proposed to contribute to a network subserving spatially guided behavior.

Adult↗

PubMed2002

[Initial results with the Munich knee simulator].

In orthopaedics more than 50 different clinical knee joint evaluation tests exist that have to be trained in orthopaedic education. Often it is not possible to obtain sufficient practical training in a clinical environment. The training can be improved by Virtual Reality technology. In the frame of the Munich Knee Joint Simulation project an artificial leg with anatomical properties is attached by a force-torque sensor to an industrial robot. The recorded forces and torques are the input for a simple biomechanical model of the human knee joint. The robot is controlled in such way that the user gets the feeling he moves a real leg. The leg is embedded in a realistic environment with a couch and a patient on it.

Artificial Limbs↗

PubMed1988

Prevention of occupational skin disease.

Each occupational setting has unique risks for occupational skin disease based on the materials used, the workplace environment, and the skin type of each worker. Virtually all programs for the prevention of skin disease can be designed around the principles outlined in this article. Most problems can be eliminated by well-designed prevention programs. All workers are entitled to a safe working environment that reduces to the extent possible the risks of acquiring occupational skin disease.

Acne Vulgaris↗

PubMed2006

'You have a message here': enhancing interpersonal communication in a hospital ward with location-based virtual notes.

OBJECTIVES: This paper aims to explore how computerized interpersonal information can be mediated through the physical environment of hospital wards. Specifically, it focuses on a communication service (location-based virtual notes) that allows hospital workers to leave short digital messages at relevant physical locations (e.g. by a patient bed), so that intended colleagues can pick them up later when entering such a location. In a work setting where personnel move between various locations mainly as a result of work priority, improving timeliness of information and reducing the number of work interruptions is essential. Our objective is to provide a set of user-motivated design guidelines that address important usability aspects of the proposed communication service. METHODS: To get end user feedback, a prototype was built and tested in simulated scenarios with real hospital workers. The material gathered from the usability testing and following interviews was reviewed to identify critical usability issues. RESULTS: We identified a number of relevant usability issues concerning the applied design metaphor, posting of digital messages, role-based contact, and user control. These issues formed the basis for a set of preliminary design principles. CONCLUSIONS: We view the preliminary usability guidelines as an incentive for more extensive research. Based on feedback from the test participants, we conclude that the location-based virtual notes have promising potential to improve timeliness of ad hoc information exchange between hospital workers.

Attitude of Health Personnel↗

PubMed2000

Dimensions of care for dementia sufferers in long-term care institutions: are they related to outcomes?

OBJECTIVES: This study empirically examined whether dimensions of care cluster in special care units (SCUs) compared with non-SCUs. The relationship between SCU status plus separate measures of the dimensions of care and outcomes for dementia sufferers was then investigated. METHODS: Data were drawn from the Intermediate Care Facility Project. The sample (N = 510) included residents with dementia, aged 65 and older, in intermediate care facilities throughout the province of British Columbia. Canada. Longitudinal data included 6 outcomes: cognitive function, behavioral problems of agitation and social skills, physical functioning, and quality of life measured through affect and expressive language skills. Separate multiple linear regression equations were estimated, relating each of these outcomes to 5 dimensions of care: preadmission and admission procedures. staff training and education, nonuse of physical and chemical restraints, flexible care routines and resident-relevant activities, and the environment. RESULTS: The results showed there is virtually no clustering of dimensions along SCU/non-SCU lines. Neither SCU status nor the individual dimensions were highly predictive of outcomes. Residents' affect at t1 emerged as a characteristic that was significantly correlated with other outcomes. DISCUSSION: This Canadian research can be added to the few but growing number of rigorous studies that suggest SCUs are not homogeneous and do not necessarily provide better care than non-SCUs. Moreover, it raises questions about the benefits of "best practice" dimensions of care, regardless of SCU status.

Aged↗

PubMed2003

From extreme environments to biologically active exopolysaccharides.

In the course of the discovery of novel polysaccharides of biotechnological interest, it is now widely accepted that extremophilic microorganisms will provide a valuable resource not only for exploitation in novel biotechnological processes but also as models for investigating how biomolecules are stabilized when subjected to extreme conditions. Microbes isolated from extreme environments offer a great diversity in chemical and physical properties of their EPS as compared to anywhere else in the biosphere. Bacteria from remote areas still remain virtually unexplored and there is not doubt that extreme environments are a rich source of microorganisms of biotechnological importance. A number of interesting and unique bacterial polysaccharides have been isolated from these ecosystems and are expected to find applications in the very near future in different industrial. Further screenings are underway as well as research into understanding the structure-function relationships of these unusual polymers.

Alteromonas↗

PubMed2004

Internet-based virtual classroom and educational management software enhance students' didactic and clinical experiences in perfusion education programs.

A challenge faced by many university-based perfusion education (PE) programs is the need for student clinical rotations at hospital locations that are geographically disparate from the main educational campus. The problem has been addressed through the employment of distance-learning environments. The purpose of this educational study is to evaluate the effectiveness of this teaching model as it is applied to PE. Web-based virtual classroom (VC) environments and educational management system (EMS) software were implemented independently and as adjuncts to live, interactive Internet-based audio/video transmission from classroom to classroom in multiple university-based PE programs. These Internet environments have been used in a variety of ways including: 1) forum for communication between the university faculty, students, and preceptors at clinical sites, 2) didactic lectures from expert clinicians to students assigned to distant clinical sites, 3) small group problem-based-learning modules designed to enhance students analytical skills, and 4) conversion of traditional face-to-face lectures to asynchronous learning modules. Hypotheses and measures of student and faculty satisfaction, clinical experience, and learning outcomes are proposed, and some early student feedback was collected. For curricula that emphasize both didactic and clinical education, the use of Internet-based VC and EMS software provides significant advancements over traditional models. Recognized advantages include: 1) improved communications between the college faculty and the students and clinical preceptors, 2) enhanced access to a national network of clinical experts in specialized techniques, 3) expanded opportunity for student distant clinical rotations with continued didactic course work, and 4) improved continuity and consistency of clinical experiences between students through implementation of asynchronous learning modules. Students recognize the learning efficiency of on-line information presentation but still prefer the traditional face-to-face classroom environment. Traditional paradigms impose limitations that are rooted in dependence upon the students and instructors being physically located in the same place at the same time. These represents significant impediments for PE programs that use geographically separate clinical sites to provide clinical experience. Historically this has led to a disintegration of the presentation of theory, and a reduction in the quantity or quality of clinical experience opportunities. New PE models help to eliminate limitations and improve the quality of education especially in the face of economic challenges. Perfusion education students and faculty will have to work together to find computer-based offerings that are equivalent to traditional classroom methods.

Allied Health Personnel↗

PubMed2006

LONI visualization environment.

Over the past decade, the use of informatics to solve complex neuroscientific problems has increased dramatically. Many of these research endeavors involve examining large amounts of imaging, behavioral, genetic, neurobiological, and neuropsychiatric data. Superimposing, processing, visualizing, or interpreting such a complex cohort of datasets frequently becomes a challenge. We developed a new software environment that allows investigators to integrate multimodal imaging data, hierarchical brain ontology systems, on-line genetic and phylogenic databases, and 3D virtual data reconstruction models. The Laboratory of Neuro Imaging visualization environment (LONI Viz) consists of the following components: a sectional viewer for imaging data, an interactive 3D display for surface and volume rendering of imaging data, a brain ontology viewer, and an external database query system. The synchronization of all components according to stereotaxic coordinates, region name, hierarchical ontology, and genetic labels is achieved via a comprehensive BrainMapper functionality, which directly maps between position, structure name, database, and functional connectivity information. This environment is freely available, portable, and extensible, and may prove very useful for neurobiologists, neurogenetisists, brain mappers, and for other clinical, pedagogical, and research endeavors.

Brain Mapping↗

PubMed2002

A telemedicine model for integrating point-of-care testing into a distributed health-care environment.

Centralized testing demands costly laboratories, which are inefficient and may provide poor services. Recent advances make it feasible to move clinical testing nearer to patients and the requesting physicians, thus reducing the time to treatment. Internet technologies can be used to create a virtual laboratory information system in a distributed health-care environment. This allows clinical testing to be transferred to a cooperative scheme of several point-of-care testing (POCT) nodes. Two pilot virtual laboratories were established, one in Italy (AUSL Modena) and one in Greece (Athens Medical Centre). They were constructed on a three-layer model to allow both technical and clinical verification. Different POCT devices were connected. The pilot sites produced good preliminary results in relation to user acceptance, efficiency, convenience and costs. Decentralized laboratories can be expected to become cost-effective.

Clinical Laboratory Information Systems↗

PubMed1996

Phosphorylation-induced torsion-angle strain in the active center of HPr, detected by NMR and restrained molecular dynamics refinement.

The structure of the phosphorylated form of the histidine-containing phosphocarrier protein HPr from Escherichia coli has been solved by NMR and compared with that of unphosphorylated HPr. The structural changes that occur upon phosphorylation of His 15, monitored by changes in NOE patterns, 3JNHH alpha-coupling constants, and chemical shifts, are limited to the region around the phosphorylation site. The His15 backbone torsion angles become strained upon phosphorylation. The release of this strain during the phosphoryl-transfer to Enzyme II facilitates the transport of carbohydrates across the membrane. From an X-ray study of Streptococcus faecalis HPr (Jia Z, Vandonselaar M, Quail JW, Delbaere LTJ, 1993, Nature 361:94-97), it was proposed that the observed torsion-angle strain at residue 16 in unphosphorylated S. faecalis HPr has a role to play in the protein's phosphocarrier function. The model predicts that this strain is released upon phosphorylation. Our observations on E. coli HPr in solution, which shows strain only after phosphorylation, and the fact that all other HPrs studied thus far in their unphosphorylated forms show no strain either, led us to investigate the possibility that the crystal environment causes the strain in S. faecalis HPr. A 1-ns molecular dynamics simulation of S. faecalis HPr, under conditions that mimic the crystal environment, confirms the observations from the X-ray study, including the torsion-angle strain at residue 16. The strain disappeared, however, when S. faecalis HPr was simulated in a water environment, resulting in an active site configuration virtually the same as that observed in all other unphosphorylated HPrs. This indicates that the torsion-angle strain at Ala 16 in S. faecalis HPr is a result of crystal contacts or conditions and does not play a role in the phosphorylation-dephosphorylation cycle.

Bacterial Proteins↗