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At least 955 records · Page 53Linked to original sources
PubMed1996

Virtual reality enhanced surgical conference system.

We present our ongoing work on an enhanced surgical conference system with a technology of virtual reality (VR). We reported on a surgical simulation support system by using a technology of virtual reality last year. In the present time, while using our VR simulation system, we realized that many surgeons and nurses needed to see both a solid real image and a virtual image of the surgical operation at the same time. According to this reason we added a solid video system to our previous VR simulation system. The new system can display both real and virtual images on 100 inch wide screen and a console monitor of Onyx computer. The doctors can see both images with shutter glasses on the screen or console. We can now simulate various cancer surgery while watching the real solid surgical picture. We expect our enhanced surgical conference system to be beneficial for surgeons and nurses with limited experience to familiarize surgical procedures. The system could be also employed in planning a surgical procedure and educating medical staffs. Here we discuss about the aim of the system, current implementation, its limitations and its future directions.

Computer Simulation↗
PubMed1997

Virtual reality in the assessment of neuromotor diseases: measurement of time response in real and virtual environments.

This paper deals with the design and the development of an equipment, called DDI, as acronym for Disease Detector, developed for the quantitative analysis of neuromotor diseases. It measures the reaction of a person evaluating in the motion of one finger of the hand the time response, the velocity of phalanxes, the force exerted from the finger against a button. The condition of motion are ballistic motion, controlled motion guided by vision, controlled motion without vision, motion with a virtual reality modelization on the computer screen. The system performs also the requirements for medical applications and with its portability and accordance to European normative for safety and quality, represents a new step towards the possibility of quantitative analysis of the performances of the human hand both of mechanical phenomenon and electromyographic of neuromotor diseases, which provoke a decrease in upper and lower limbs action.

Computer Graphics↗
PubMed2000

["Virtual colonoscopy": back to the future?].

"Virtual colonoscopy" is a new method of producing an endoscopic view of the colon without endoscopy. The images are derived from the data of conventional abdominal computer-tomography or magnetic resonance tomography, using modern computer programmes. The method makes it possible to detect colonic polyps or carcinomas with a sensitivity and specificity of 80%. The most interesting application of "virtual colonoscopy" may be as a screening method for colorectal polyps in preventing the development of colorectal cancer. This may improve patient acceptance for colorectal cancer screening programmes.

Colonic Neoplasms↗
PubMedDate not supplied

U.S. agencies providing publicly funded contraceptive services in 1999.

CONTEXT: Nearly one-quarter of women who obtain medical contraceptive services receive care from clinics operated by publicly funded agencies. In light of changes in government policy and funding and in the structure of health care financing, an assessment of agency policies and programs is essential for monitoring women's access to contraceptive care and services. METHODS: In 1999, 637 of a nationally representative sample of 1,016 U.S. agencies that receive public funding to provide contraceptive services responded to a 12-page survey. Responses were analyzed according to agency type, receipt of Title X funding and main focus. RESULTS: More than nine in 10 agencies offer the pill, the male condom and the injectable; 80% offer emergency contraceptive pills, compared with 38% in 1995. Some agencies allow clients to delay a pelvic exam when beginning use of oral contraceptives (56%), the injectable (42%) or the implant (23%). On average, agencies receive funding for contraceptive services from 4.9 sources; the proportion relying on private insurance and contributions has risen since 1995. Virtually all family planning agencies provide screening and testing for sexually transmitted diseases (STDs), and at least two-thirds offer treatment for most STDs. The vast majority of agencies offer general health care and perinatal or pediatric services; half offer general gynecologic care or infertility services. Services provided, costs and clinic policies vary according to agency type. CONCLUSIONS: Agencies offering contraceptive services also offer a wide range of reproductive health and related services. There remain services for which provision could be increased and policies that need to be modified to facilitate clients' access to contraceptive care.

Contraception↗
PubMed1982

[Left-ventricular thrombosis in recent myocardial infarction. An echocardiographic study].

To evaluate the incidence of left-ventricular thrombosis (LVT) in recent myocardial infarction (MI), M-mode and two-dimensional echocardiography (2DE) were performed in 200 patients enrolled in a rehabilitation program, three to 12 weeks after the acute episode (average 6 weeks). LVT was detected in 36 of 125 patients with anterior MI and in 4 of 75 patients with inferior MI. The presence of LVT correlated well with the electrocardiographic extension of myocardial necrosis; 90% of LVT was detected in patients with extensive MI. The same behaviour seems to be found in MI without evidence of ECG Q waves: 3 of 8 patients with extensive non-transmural MI had LVT. All thrombi were located at the apex. For this reason the apical acoustic window is the most useful in diagnosing LVT. All patients with LVT showed severe apical wall-motion abnormalities (akinesis, dyskinesis, aneurysm); the motion of the lower-posterolateral, septal and anterolateral segments was also frequently abnormal. None of the 40 patients with LVT had clinical evidence of systemic embolization during the in-hospital period. M-mode recordings wer of no help. Left ventricular diastolic dimensions and fractional shortening could not identify subgroups of patients at risk for LVT. In conclusion, patients with a recent large MI and severe apical wall-motion abnormalities are at high risk for LVT; nevertheless, the risk of systemic embolization seems to be virtually absent. 2DE is a useful screening technique for detecting LV in patients with recent MI before cineventriculography and cardiac surgery.

Adult↗
PubMed2005

Determinants guiding alternate foot placement selection and the behavioral responses are similar when avoiding a real or a virtual obstacle.

In this study we validate the use of a virtual planar obstacle paradigm to study the avoidance of a real obstacle, such as a hole, during locomotion. Also we further validate the economy determinant implicated with the minimization of foot displacement from its normal landing position during alternate foot placement. Participants were asked to perform two blocks of trials: real (a real hole was embedded in the pathway and participants were requested to avoid stepping into it) and virtual (a virtual planar obstacle was displayed on the screen of a liquid crystal display monitor). Trunk and feet kinematics were monitored, as well as electromyography (EMG) activity of 14 muscles of both lower limbs and trunk. The results of this study showed that the dominant choice for each obstacle investigated was not different between the real and virtual conditions. In addition, dynamic stability, economy and forward progression determinants guiding alternate foot placement were similarly satisfied. Thus the use of virtual planar obstacle in adaptive locomotion study is appropriate. EMG data were used to compute an index relating the changes in muscle activity relative to the normal walking profile. This EMG index was significantly and positively correlated with the amount of foot displacement for the adaptive step. The fact that the dominant choice resulted in minimum foot displacement from its normal landing spot combined with minimal changes in muscle activity validates conclusively the economy determinant.

Adolescent↗
PubMed1996

[Plasma (1-->3)-beta-D-glucan determination for screening deep mycosis].

Plasma (1-->3)-beta-D-glucan determination has been developed for the diagnosis of fungemia and deep mycosis to make up for the low yield of blood culture. This method uses Factor G, a coagulation enzyme of the horseshoe crab that is highly sensitive to this glucan. Since (1 -->3)-beta-D-glucan is a characteristic fungal cell-wall constituent which is common to virtually all fungi, the method aims to screen fungal infections as a whole. This is advantageous today when new fungi are appearing one after another as a causative agent of opportunistic deep fungal infections. Plasma (1-->3)-beta-D-glucan concentrations in 60 normal individuals were less than 10pg/ml. With a cutoff value at 20pg/ml, the sensitivity of the test was 90%, and the specificity was 100%. No cases of fungal colonization showed values above the cutoff level. In addition to invasive candidiasis, aspergillosis, and cryptococcosis, trichosporonosis was also found positive with the test. Glucanemia was not associated with primary cryptococcosis, probably because the growth of the organism is checked by the competent immunity in these afebrile patients. Levels of plasma (1-->3)-beta-D-glucan were variable in aspergilloma, indicating that the disease is essentially a colonization, but that (1-->3)-beta-D-glucan may appear in the blood when cavitary walls are invaded, depending on the integrity of local or systemic immunity. In addition to being useful for diagnosis, the test is also helpful in initiating early treatment of deep mycosis with improved survival.

Clinical Trials as Topic↗
PubMed1995

First seizures associated with playing electronic screen games: a community-based study in Great Britain.

Active surveillance by virtually all electroencephalographic departments throughout Great Britain identified 118 patients who had a first seizure while playing an electronic screen game during two 3-month periods. Patients were divided into Group A (46 patients)--those for whom there was thought to be a definite causal relationship (type 4 photoparoxysmal response); Group B (25 patients)--those for whom there was a probable causal relationship (types 1-3 photoparoxysmal response, clinical evidence of photosensitivity, subsequent recurrent seizures on repeat exposure to electronic screen games, and/or occipital spikes in the resting electroencephalogram); and Group C (47 patients)--those for whom there was no apparent causal relationship. The number of patients in Group C did not exceed that expected by the chance occurrence of two common events (playing electronic screen games and incidence of epilepsy). Most (103/118) of the patients were in the age range of 7 to 19 years. Within this age group the annual incidence of first seizures triggered by playing electronic screen games (Groups A and B combined) was estimated to be 1.5/100,000.

Adolescent↗
PubMed2001

Complex gel permeation assays for screening combinatorial libraries.

Gel permeation methods have been commonly used to screen combinatorial libraries synthesized on a solid support. We report here three screens of combinatorial libraries using gel permeation assays. These include a simple enzymatic assay to identify inhibitors of the influenza enzyme neuraminidase, and two more complex assays designed to screen for inhibitors of the interleukin-8 (IL-8)-IL-8 receptor and the urokinase-urokinase receptor interactions, respectively. The IL-8 ligand-receptor assay makes use of IL-8 receptor-expressing cells attached to a membrane, thus enabling washing steps as part of the assay. The urokinase ligand-receptor assay employs an enzyme-linked immunosorbent assay-type format, previously thought to be amenable only to well-based assays. The results of these three screens are reported here, including the discovery of a novel series of acyclic inhibitors of neuraminidase. The development of complex assays in a gel permeation format allows for the routine screening of combinatorially as well as noncombinatorially made compound collections against virtually any kind of target, and is being widely used in our high throughput screening operations.

Chromatography, Gel↗
PubMedDate not supplied

Development of a Remote Accessibility Assessment System through three-dimensional reconstruction technology.

A Remote Accessibility Assessment System (RAAS) that uses three-dimensional (3-D) reconstruction technology is being developed; it enables clinicians to assess the wheelchair accessibility of users' built environments from a remote location. The RAAS uses commercial software to construct 3-D virtualized environments from photographs. We developed custom screening algorithms and instruments for analyzing accessibility. Characteristics of the camera and 3-D reconstruction software chosen for the system significantly affect its overall reliability. In this study, we performed an accuracy assessment to verify that commercial hardware and software can construct accurate 3-D models by analyzing the accuracy of dimensional measurements in a virtual environment and a comparison of dimensional measurements from 3-D models created with four cameras/settings. Based on these two analyses, we were able to specify a consumer-grade digital camera and PhotoModeler (EOS Systems, Inc, Vancouver, Canada) software for this system. Finally, we performed a feasibility analysis of the system in an actual environment to evaluate its ability to assess the accessibility of a wheelchair user's typical built environment. The field test resulted in an accurate accessibility assessment and thus validated our system.

Computer Graphics↗
PubMedDate not supplied

A virtual reality patient simulation system for teaching emergency response skills to U.S. Navy medical providers.

Rapid and effective medical intervention in response to civil and military-related disasters is crucial for saving lives and limiting long-term disability. Inexperienced providers may suffer in performance when faced with limited supplies and the demands of stabilizing casualties not generally encountered in the comparatively resource-rich hospital setting. Head trauma and multiple injury cases are particularly complex to diagnose and treat, requiring the integration and processing of complex multimodal data. In this project, collaborators adapted and merged existing technologies to produce a flexible, modular patient simulation system with both three-dimensional virtual reality and two-dimensional flat screen user interfaces for teaching cognitive assessment and treatment skills. This experiential, problem-based training approach engages the user in a stress-filled, high fidelity world, providing multiple learning opportunities within a compressed period of time and without risk. The system simulates both the dynamic state of the patient and the results of user intervention, enabling trainees to watch the virtual patient deteriorate or stabilize as a result of their decision-making speed and accuracy. Systems can be deployed to the field enabling trainees to practice repeatedly until their skills are mastered and to maintain those skills once acquired. This paper describes the technologies and the process used to develop the trainers, the clinical algorithms, and the incorporation of teaching points. We also characterize aspects of the actual simulation exercise through the lens of the trainee.

Algorithms↗
PubMed2006

[Screening and prevention of carcinoma of the colon and rectum].

Carcinoma of the colon and rectum is the third most frequent malignant disease in industrialised countries. Incidence and mortality of colon cancer can be effectively lowered by population screening. The individual risk status of the patient has to be assessed before the screening procedure. In people with an average risk screening should be performed after the 50th birthday. The choice of the applied procedure (endoscopic procedures or fecal occult blood test) depends on the individual situation of the patient. Complete colonoscopy has the highest sensitivity and specificity for the detection of adenomas or carcinomas and should therefore be offered first. Alternatively flexible sigmoidoscopy or repetitive testing for occult blood can be applied. Despite promising developments in the radiographic detection of colonic lesions, virtual colonoscopy cannot be recommended as a screening procedure.

Colonic Neoplasms↗
PubMed2006

Surface visualization at 3D endoluminal CT colonography: degree of coverage and implications for polyp detection.

BACKGROUND & AIMS: Effective colonoscopic screening for polyps, whether by optical or virtual means, requires adequate visualization of the entire colonic surface. The purpose of this study was to assess prospectively the degree of surface coverage at 3-dimensional (3D) endoluminal computed tomography colonography (CTC) after retrograde fly-through, combined retrograde-antegrade fly-through, and review of remaining missed regions. METHODS: The study group consisted of 223 asymptomatic adults (mean age, 57.8 +/- 7.2 y; 111 men, 112 women) undergoing primary CTC screening. CTC studies were interpreted by experienced readers using a primary 3D approach. The CTC software system that was used continually tracks the percentage of endoluminal surface visualized. The degree of coverage was assessed prospectively after retrograde and combined retrograde-antegrade navigation. The added effect of reviewing missed regions was also assessed prospectively. RESULTS: The mean surface coverage after only retrograde 3D endoluminal fly-through from rectum to cecum was 76.6% +/- 4.8% (range, 63%-92%); coverage was 80% or less in 181 (81.2%) patients. Antegrade navigation back to the rectum increased the overall coverage to 94.1% +/- 2.3% (range, 84%-99%; P < .0001). A review of missed regions 300 mm(2) or larger increased coverage to 97.9% +/- 1.1% (range, 93%-99%; P < .0001) and added 21.4 +/- 11.4 seconds to the interpretation time (range, 3-67 s). CONCLUSIONS: Combined bidirectional retrograde and antegrade 3D navigation, supplemented by rapid review of missed regions, effectively covers the entire evaluable surface at CTC. Unidirectional retrograde 3D fly-through typically excludes 20% or more of the endoluminal surface, which may provide insight into potential limitations at optical colonoscopy.

Aged↗
PubMed2004

Adherence with colorectal cancer screening guidelines: a review.

OBJECTIVE: To review screening rates and factors impacting patient utilization of colorectal cancer screening tests. METHODS: We searched Medline, CancerLit, and PsycInfo for articles on colorectal cancer screening adherence. US studies on average-risk individuals were reviewed to identify: (1) utilization/adherence rates, (2) predictors of patient adherence, (3) correlation between long-term adherence and type of test selected, (4) predictors of physician recommendation of screening tests, and (5) patterns in the type of test recommended by physicians. RESULTS: In 2000, only 34% of the US population obtained screening within recommended time frames (fecal occult blood test annually, flexible sigmoidoscopy every 5 years, or colonoscopy every 10 years). Positive attitude toward screening and physician recommendation result in high adherence while fear of finding cancer and the belief that cancer is fatal result in low adherence. Physician specialty impacts the type of test recommended, while perceived lack of patient adherence is not a consistent barrier to recommending screening tests. Matching individuals with their choice of screening test and newer technology, such as virtual colonoscopy, may help increase adherence. CONCLUSION: Additional studies are required on differences in adherence between tests, whether patient preferences impact adherence, and how the physician-patient relationship can be fostered to increase adherence.

Colorectal Neoplasms↗
PubMed2002

Flexible sigmoidoscopy for colorectal cancer screening: valid approach or short-sighted?

Flexible sigmoidoscopy is a safe, effective test that may be delivered feasibly on a large scale for mass colorectal cancer screening. Flexible sigmoidoscopy is 67% to 80% as sensitive as colonoscopy in a screening population, but is probably 10 to 20 times safer than colonoscopy in terms of complications. Several national guidelines recommend combining flexible sigmoidoscopy with fecal occult blood tests. There is limited evidence to support this practice, and the added benefit to an existing flexible sigmoidoscopy screening program although real, may be marginal. In the future, it is likely that flexible sigmoidoscopy screening among patients aged 50 to 65 will be supplemented with total colonic screening, using molecular-based fecal tests or virtual colonoscopy, after age 65.

Clinical Trials as Topic↗
PubMed1995

The epidemiology, mortality and morbidity of tuberculosis in Australia: 1850-94.

The review covers the four major changes in the history of tuberculosis in Australia from 1850 to 1994. During the first 100 years there was no significant effective treatment. Mass miniature radiological chest screening and effective bacteriological examination of World War II army recruits resulted in reliable diagnosis. The Australian Tuberculosis Campaign 1948-76 utilized the army experience for detection, and the use of specific treatment virtually eliminated the disease. Failure to maintain strict screening of high-risk groups, especially immigrants, has led to a resurgence of tuberculosis as shown by an increase in notifications in adults and prevalence rates in secondary school children.

Australia↗
PubMed2001

Different brain correlates for watching real and virtual hand actions.

We investigated whether observation of actions reproduced in three-dimensional virtual reality would engage perceptual and visuomotor brain processes different from those induced by the observation of real hand actions. Participants were asked to passively observe grasping actions of geometrical objects made by a real hand or by hand reconstructions of different quality in 3D virtual reality as well as on a 2D TV screen. We found that only real actions in natural environment activated a visuospatial network including the right posterior parietal cortex. Observation of virtual-reality hand actions engaged prevalent visual perceptual processes within lateral and mesial occipital regions. Thus, only perception of actions in reality maps onto existing action representations, whereas virtual-reality conditions do not access the full motor knowledge available to the central nervous system.

Adult↗
PubMed1994

Current approaches to genetic metabolic screening in newborns.

Genetic metabolic screening in newborn infants includes both specific testing for clinical indications in sick neonates and routine newborn screening. The decision of which sick neonates should have metabolic testing is based on the clinical phenotype and the results of general laboratory analyses, with particular attention to hypoglycemia, metabolic acidosis, and hyperammonemia. Metabolic tests include analyses for amino acids and organic acids and a carnitine profile. Routine newborn screening should be performed on all neonates prior to hospital discharge but no later than the 3rd day of life. The disorders covered by newborn screening vary among the states and among countries but virtually always include phenylketonuria and congenital hypothyroidism and often include sickle cell disease and galactosemia. Other metabolic disorders that may be included in newborn screening are maple syrup urine disease, homocystinuria, biotinidase deficiency, and congenital adrenal hyperplasia.

Humans↗