Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Computer Systems”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,531 records · Page 85Linked to original sources
PubMed2006

[Characteristics and applications of a flat panel computer tomography system].

PURPOSE: To assess a new flat panel volume computed tomography (FP-VCT) with very high isotropic spatial resolution as well as high Z-axis coverage. MATERIALS AND METHODS: The prototype of an FP-VCT scanner with a detector cell size of 0.2 mm was used for numerous phantom studies, specimen examinations, and animal research projects. RESULTS: The high spatial resolution of the new system can be used to accurately determine solid tumor volume, thus allowing for earlier assessment of the therapeutic response. In animal experimentation, whole-body perfusion mapping of mice is feasible. The high spatial resolution also improves the classification of coronary artery atherosclerotic plaques in the isolated post mortem human heart. With the depiction of intramyocardial segments of the coronary arteries, investigations of myocardial collateral circulation are feasible. In skeletal applications, an accurate analysis of the smallest bony structures, e. g., petrous bone and dental preparations, can be successfully performed, as well as investigations of repetitive studies of fracture healing and the treatment of osteoporosis. CONCLUSION: The introduction of FP-VCT opens up new applications for CT, including the field of molecular imaging, which are highly attractive for future clinical applications. Present limitations include limited temporal resolution and necessitate further improvement of the system.

Animals↗
PubMed2004

High-risk HPV detection by Hybrid Capture and ploidy determination by a computer-assisted system in cervical biopsies.

OBJECTIVE: To correlate high-risk HPV (hrHPV) detection by Hybrid Capture II (HC2) (Digene, Gaithersburg, Maryland, U.S.A.) with DNA content (ploidy) of cervical biopsies analyzed by a computer-assisted system. STUDY DESIGN: Cervical biopsies from 54 women examined at Leonor Mendes de Barros Hospital, São Paulo, as part of the Latin American Screening study during 2002--2003, were tested for hrHPV with HC2. All patients had been referred for colposcopic examination due to an abnormal cervical cytology. The final diagnosis included 30 cervicitis, 14 cervical intraepithelial neoplasia (CIN) 1, 5 CIN 2, 4 CIN 3 and 1 squamous cell carcinoma (SCC). Five-micrometer sections of each biopsy were stained with Feulgen-tionine and evaluated with the CAS 200 System (Becton Dickinson, U.S.A.), using the 3.0 software (version 8.1) of the DNA Quantitative Measurement Program (Becton Dickinson). Ploidy was evaluated from histograms obtained by analyzing atypical nuclei. RESULTS: Of the 30 cervicitis cases, 28 (93.3%) were diploid, and hrHPV was detected in 8 (28.5%) of the cases. Two tetraploid cervicitis lesions were observed, 1 positive and 1 negative for hrHPV. Among the CIN 1 lesions, 8 (57.1%) were diploid and 6 (42.8%) aneuploid. Of the latter, 4 (66.6%) were negative and 2 (33.3%) positive for hrHPV. Of the 5 CIN 2 lesions, 2 were diploid, 2 aneuploid and 1 tetraploid; all were positive for hrHPV. All CIN 3 lesions and the SCC proved to be aneuploid and positive for hrHPV. CONCLUSION: The data suggest that the majority of cervicitis and CIN 1 lesions are diploid and negativef or hrHPV. This is in sharp contrast to high grade CIN 2-3 lesions, all of which were positive for hrHPV in this study and also aneuploid, consistent with their progressive potential.

Carcinoma, Squamous Cell↗
PubMed2004

Design and implementation of an SVM-based computer classification system for discriminating depressive patients from healthy controls using the P600 component of ERP signals.

A computer-based classification system has been designed capable of distinguishing patients with depression from normal controls by event-related potential (ERP) signals using the P600 component. Clinical material comprised 25 patients with depression and an equal number of gender and aged-matched healthy controls. All subjects were evaluated by a computerized version of the digit span Wechsler test. EEG activity was recorded and digitized from 15 scalp electrodes (leads). Seventeen features related to the shape of the waveform were generated and were employed in the design of an optimum support vector machine (SVM) classifier at each lead. The outcomes of those SVM classifiers were selected by a majority-vote engine (MVE), which assigned each subject to either the normal or depressive classes. MVE classification accuracy was 94% when using all leads and 92% or 82% when using only the right or left scalp leads, respectively. These findings support the hypothesis that depression is associated with dysfunction of right hemisphere mechanisms mediating the processing of information that assigns a specific response to a specific stimulus, as those mechanisms are reflected by the P600 component of ERPs. Our method may aid the further understanding of the neurophysiology underlying depression, due to its potentiality to integrate theories of depression and psychophysiology.

Case-Control Studies↗
PubMed2006

Enabling persons with multiple disabilities to choose among environmental stimuli and request stimulus repetitions through microswitch and computer technology.

This study assessed microswitch and computer technology to enable two participants with multiple disabilities, 32 and 19 years of age, to choose among environmental stimuli and request their repetition whenever they so desired. Within each session, 18 stimuli (12 preferred and 6 nonpreferred) were available. For each stimulus, a computer system provided a sample of 3 sec. duration. During the intervention, participants' vocal responding in relation to a stimulus sample activated a microswitch and a computer system turned on that stimulus for 15-30 sec. When participants did not vocally respond, the computer system paused briefly and then presented the next scheduled stimulus sample. When participants vocally responded at the end of a stimulus presentation, the stimulus was repeated. Intervention data showed that the participants learned to choose preferred stimuli and bypass nonpreferred ones as well as to request repetitions of the preferred stimuli. This performance was maintained at a 1-mo. postintervention check and transferred to sets of stimuli not used in the intervention. The implications of these results were discussed.

Adult↗
PubMedDate not supplied

Public safety answering point readiness for wireless E-911 in New York State.

OBJECTIVE: To determine the level of wireless enhanced 911 readiness among New York's primary public safety answering points. METHODS: This descriptive study utilized a simple, single-page survey that was distributed in August 2001, with telephone follow-up concluding in January 2002. Surveys were distributed to directors of the primary public safety answering points in each of New York's 62 counties. Information was requested regarding current readiness for providing wireless enhanced 911 service, hardware and software needs for implementing the service, and the estimated costs for obtaining the necessary hardware and software. RESULTS: Two directors did not respond and could not be contacted by telephone; three declined participation; one did not operate an answering point; and seven provided incomplete responses, resulting in usable data from 49 (79%) of the state's public safety answering points. Only 27% of the responding public safety answering points were currently wireless enhanced 911 ready. Specific needs included obtaining or upgrading computer systems (16%), computer-aided dispatch systems (53%), mapping software (71%), telephone systems (27%), and local exchange carrier trunk lines (42%). The total estimated hardware and software costs for achieving wireless enhanced 911 readiness was between 16 million and 20 million dollars. CONCLUSIONS: New York's primary public safety answering points are not currently ready to provide wireless enhanced 911 service, and the cost for achieving readiness could be as high as 20 million dollars.

Cell Phone↗
PubMed2005

A systems-based computational model for dose-response comparisons of two mode of action hypotheses for ethanol-induced neurodevelopmental toxicity.

Investigations into the potential mechanisms for ethanol-induced developmental toxicity have been ongoing for over 30 years since Fetal Alcohol Syndrome (FAS) was first described. Neurodevelopmental endpoints are particularly sensitive to in utero exposure to alcohol as suggested by the more prevalent alcohol-related neurodevelopmental disorder (ARND). The inhibition of proliferation during neurogenesis and the induction of apoptosis during the period of synaptogenesis have been identified as potentially important mechanisms for ARND. However, it is unclear how these two mechanisms quantitatively relate to the dose and timing of exposure. We have extended our model of neocortical neurogenesis to evaluate apoptosis during synaptogenesis. This model construct allows quantitative evaluation of the relative impacts on neuronal proliferation versus apoptosis during neocortical development. Ethanol-induced lengthening of the cell cycle of neural progenitor cells during rat neocortical neurogenesis (G13-G19) is used to compute the number of neurons lost after exposure during neurogenesis. Ethanol-induced dose-dependent increases in cell death rates are applied to our apoptosis model during rat synaptogenesis (P0-P14), when programmed cell death plays a major role in shaping the future neocortex. At a human blood ethanol concentration that occurs after 3-5 drinks ( approximately 150 mg/dl), our model predicts a 20-30% neuronal deficit due to inhibition of proliferation during neurogenesis, while a similar exposure during synaptogenesis suggests a 7-9% neuronal loss through induction of cell death. Experimental in vitro and in vivo dose-response research and stereological research on long-term neuronal loss after developmental exposure to ethanol is compared to our model predictions. Our computational model allows for quantitative, systems-level comparisons of mechanistic hypotheses for perturbations during specific neurodevelopmental periods.

Animals↗
PubMed1995

[The design and application of speech signal processing system by computer in stomatology.].

In this study we established a computer bases on Speech Signal Processing System and changes of formant frequencies of the vowel/i/accompany the changes in the oral cavity after maxillary surgery and prosthodontic reconstruction.The study found the F1 for vowel/i/has no change,while the F2 peak significantly shifted between the preprosthetic and postprosthetic speaking condition after anterior resection of relative energy error value and the speech intelligible measured aurally(P<0.05).

English Abstract↗
PubMed1996

Scatter-to-primary ratio and absorption efficiency in screen-film and computed radiography systems.

PURPOSE: To determine whether the scatter-to-primary (s/p) ratio, measured on a screen-film or computed radiographic (CR) system, varies with chemical composition or primary attenuation properties. MATERIALS AND METHODS: The s/p ratios of four Gd2O2S screens, three CaWO4 screens and a CR screen, were determined under uniform irradiation conditions. One simulated low scatter conditions, such as in lung imaging, and the other simulated high scatter conditions as in abdominal imaging. The absorption efficiency of each screen was measured and calculated. RESULTS: The measured s/p ratio varied within each set of screens. The s/P ratio was related to the absorption efficiency of primary radiation for the screen-film and CR system. No difference in the s/p ratio was seen between screen-film and CR systems when normalised for the primary absorption efficiency. CONCLUSIONS: Absorption efficiency of the imaging system is a major indicator of s/p ratio, for both screen-film and CR systems.

Abdomen↗
PubMed1988

An enhanced standard computer keyboard system for single-finger and typing-stick typing.

A prototype keyboard system was developed, using off-the-shelf hardware and software, as an inexpensive keyboard-based system to facilitate data entry for single-finger and typing-stick typists. Evaluation established that the system can increase entry rate by 50 percent or more. The underlying concepts may provide a basis for developing other configurations that accelerate and simplify computer keyboard use for persons with a variety of hand impairments.

Communication Devices for People with Disabilities↗
PubMed2006

EMG and EOG artifacts in brain computer interface systems: A survey.

It is widely accepted in the brain computer interface (BCI) research community that neurological phenomena are the only source of control in any BCI system. Artifacts are undesirable signals that can interfere with neurological phenomena. They may change the characteristics of neurological phenomena or even be mistakenly used as the source of control in BCI systems. Electrooculography (EOG) and electromyography (EMG) artifacts are considered among the most important sources of physiological artifacts in BCI systems. Currently, however, there is no comprehensive review of EMG and EOG artifacts in BCI literature. This paper reviews EOG and EMG artifacts associated with BCI systems and the current methods for dealing with them. More than 250 refereed journal and conference papers are reviewed and categorized based on the type of neurological phenomenon used and the methods employed for handling EOG and EMG artifacts. This study reveals weaknesses in BCI studies related to reporting the methods of handling EMG and EOG artifacts. Most BCI papers do not report whether or not they have considered the presence of EMG and EOG artifacts in the brain signals. Only a small percentage of BCI papers report automated methods for rejection or removal of artifacts in their systems. As the lack of dealing with artifacts may result in the deterioration of the performance of a particular BCI system during practical applications, it is necessary to develop automatic methods to handle artifacts or to design BCI systems whose performance is robust to the presence of artifacts.

Algorithms↗
PubMed1995

The impact of a guideline-driven computer charting system on the emergency care of patients with acute low back pain.

Federal guidelines for the treatment of acute low back pain were locally modified and made more specific. These guidelines were then programmed into a rule-based computer charting system which provides real-time advice regarding documentation, testing, treatment, and disposition of emergency department patients with this condition. In a time-series off-on experiment the system was shown to significantly improve documentation of the medical record and discharge instructions. There was little effect on the appropriateness of testing and treatment and the cost of care. These findings contrast with our previous experiment using a similar program for the care of health care workers exposed to body fluids. In that study both the appropriateness of care and the cost-effectiveness of care were substantially improved.

Acute Disease↗
PubMed1977

Evaluation of a computerized arrhythmia alarm system.

A prospective study of a computerized arrhythmia alarm system was carried out in the coronary care unit during 200 patient hours of monitoring. The computer system was designed to activate an alarm on the development of rhythm and conduction disorders including asystole, ventricular tachycardia, atrial tachycardia, sinus tachtcardia, bradycardia, frequent premature ventricular beats, atrial fibrillation and bundle branch block. Study patients were simultaneously monitored by the computer system and a conventional analog heart rate alarm system. All alarms generated by the two systems were evaluated. Of 79 computer alarms, 42 (53 percent) were true positive alarms; during the same period there were 167 analog alarms of which only 13 (8 percent) were true positive alarms. In both systems, false positive alarms were primarily due to patient movement, but they occurred only 25 percent as often with the computer system as with the analog system. These results indicate that computerized arrhythmia monitoring systems offer significant advantages over conventional monitoring techniques.

Arrhythmias, Cardiac↗
PubMed1986

A computer-aided system to evaluate postural stress in the workplace.

Stress caused by awkward working posture of the trunk and shoulders can result in fatigue, musculoskeletal disorders and nerve entrapment syndromes. To aid in evaluating the relationship between work activities and postural stress, a computer-aided system was developed. This system produces a detailed description of work tasks and a continuous record of trunk and shoulder activity on the same time scale. The system was used to evaluate postural stresses on a case study job in an automobile assembly plant. The results of the postural analysis were used to identify specific causes of postural stress and to develop recommendations for changes in work station equipment and methods to reduce stress.

Diagnosis, Computer-Assisted↗