Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Computers”

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 1,441 records · Page 80Linked to original sources
PubMed2002

A four-year experience with a stereotactic computer in a small neurosurgical department.

BACKGROUND: A stereotactic computer with a mechanical, proprioceptive arm was acquired in 1996. The aim of this report is to review the 4-year experience with frameless, computer-aided stereotaxy in a small neurosurgical department. METHODS: From 1996 to 1999 the computer was used for 121 operations. The surgical files from these operations were either retrospectively or prospectively registered. Patient and computer data, type of surgery, complications and number of surgeons were noted. The versatility, benefits, and drawbacks of the stereotactic computer were evalued based on these findings. RESULTS: Seven surgeons performed a total of 121 computer-assisted operations. The procedures consisted of 63 stereotactic tissue samplings, 44 craniotomies, 7 abscess punctures and 3 insertions of intracerebral devices (shunts and microelectrodes). Technical complications were seen in 6 cases (4.8%), but this did not affect the surgical outcome. CONCLUSIONS: The stereotactic computer has enabled the department to broaden its spectrum of procedures. High precision surgery such as stereotactic biopsy has been possible without the use of a framebased system. The results indicate that even small neurosurgical units with a limited number of procedures can safely and successfully implement neuronavigation in daily routines.

Adolescent↗
PubMed1998

Diagnostic value and tolerance of Lipiodol-computed tomography for the detection of small hepatocellular carcinoma: correlation with pathologic examination of explanted livers.

BACKGROUND/AIMS: This study aimed to assess the tolerance and the real sensitivity of Lipiodol-computed tomography in the detection of small hepatocellular carcinoma by comparison with pathological examination of the explanted livers. METHODS: Seventy-two patients with cirrhosis (Child A=8, B=36, C=28) awaiting orthotopic liver transplantation underwent Lipiodol-computed tomography to determine the presence, number and location of possible hepatocellular carcinoma nodules. Before liver transplantation six patients had a presumed single hepatocellular carcinoma diagnosed by biopsy. Liver transplantation was performed a mean of 6 months after Lipiodol-computed tomography. Explanted livers were sectioned at 0.8- to 1-cm intervals. Lipiodol-computed tomography staging and pathologic findings were compared. RESULTS: Pathologic studies showed 24 hepatocellular carcinoma nodules (diameter, 2-42 mm) not diagnosed before liver transplantation in 14 of the 72 livers. Lipiodol-computed tomography detected 6 of these 24 nodules, but none of the daughter lesions (n=9) in the six patients with a presumed single hepatocellular carcinoma. Lesion-by-lesion analysis revealed a sensitivity of 37%. Lipiodol-computed tomography falsely detected three additional nodules not confirmed by pathologic examination (1 haemangioma, 2 nondysplastic regenerating nodules). One Child C patient developed variceal bleeding within 2 days after injection of Lipiodol. CONCLUSIONS: Tolerance of this procedure was satisfactory, even in Child C patients. Lipiodol-computed tomography has a low sensitivity in the detection of small hapatocellular carcinoma. These results must be considered when liver resection or liver transplantation is proposed for the treatment of hepatocellular carcinoma.

Adult↗
PubMed1987

Computer-assisted versus unassisted analysis of the exercise electrocardiogram in patients without myocardial infarction.

Computer-assisted interpretation of the exercise electrocardiogram has been advocated to improve the accuracy of diagnosing coronary artery disease. Its accuracy was compared with a blinded visual interpretation of exercise-induced ST depression in 271 consecutive subjects without prior myocardial infarction who were referred for coronary angiography. The sensitivity of the visual and computer readings was 0.51 and 0.51, respectively, at a specificity of 0.87. Receiver operating characteristic curves were generated for the visual and computer ST depression in lead V5. Analysis of the areas under these curves showed no significant difference between them, indicating that computer-assisted analysis was not superior to unmodified visual analysis. A similar analysis was applied to two other computer indexes reported to be superior to visual assessments (treadmill exercise score and ST index). These computer indexes were not superior to a conventional visual analysis of leads I, II, V2, V4 and V5 in predicting severe disease (greater than 50% luminal narrowing). These results suggest that computer-assisted interpretation does not improve the accuracy of exercise electrocardiography in diagnosing coronary artery disease in subjects without prior myocardial infarction.

Adult↗
PubMed1994

Consumer attitudes towards computer-assisted self-care of the common cold.

Knowledge of colds and flu and attitudes towards use of computers for self-care are compared for 260 young adult users and 194 young adult non-users of computer-assisted self-care for colds and flu. Participants completed a knowledge questionnaire on colds and flu, used a computer program designed to enhance self-care for colds and flu, and then completed a questionnaire on their attitudes towards using a computer for self-care for colds and flu, and then completed a questionnaire on their attitudes towards using a computer for self-care for colds and flu, perceived importance of physician interactions, physician expertise, and patient-physician communication. Compared with users, non-users preferred personal contact with their physicians and felt that computerized health assessments would be limited in vocabulary and range of current medical information. Non-users were also more likely to agree that people could not be trusted to do an accurate computerized health assessment and that the average person was too computer illiterate to use computers for self-care.

Adult↗
PubMed1999

Computer-tailored interventions motivating people to adopt health promoting behaviours: introduction to a new approach.

This issue of Patient Education and Counseling discusses the development, application and effectiveness of computer-tailored interventions. Computer-tailored interventions are a relatively new health education approach. The interventions are characterised by the fact that the content of the materials is adapted, with the aid of computers, to the specific characteristics of a particular person. The use of computers also facilitates addressing large segments of the population, who can now receive materials that are not general but highly individualized. This thematic issue features papers dealing with a wide range of topics. These articles describe the application of behavioural change theories to this new approach, the advantages of computer-tailored interventions over more general mass media approaches, their effectiveness and future directions for research on computer-tailored interventions. This editorial paper introduces computerised tailoring and provides a brief overview of its elements and applications as well as of the papers in this issue, and summarises the main conclusions and suggestions for future research on computer-tailored interventions.

Attitude to Health↗
PubMed1999

The application and impact of computer-generated personalized nutrition education: a review of the literature.

Computer-tailored nutrition education may be more effective than general nutrition education because messages are tailored to individual behavior, needs and beliefs of subjects. Therefore, the messages are likely to be of more personal relevance and may have stronger motivational effects. Computer-generated nutrition education has been studied for different dietary behaviors, in different target populations, and in different settings. In recent years, eight studies have been published that assessed the impact of comprehensive computer-generated nutrition interventions that were based on behavior change theory. In this article, the process of providing people with computer-tailored nutrition education is described and the studies on the impact of computer-tailored nutrition education are reviewed. The results point to the conclusion that computer-tailored nutrition education is more likely to be read, remembered, and experienced as personally relevant compared to standard materials. Furthermore, computer-tailored nutrition education also appears to have a greater impact in motivating people to change their diet, their fat intake in particular, although at present no definite conclusions can be drawn.

Attitude to Health↗
PubMedDate not supplied

[Comparative study of high resolution computer-assisted tomography with chest radiograph in silicosis].

The diagnosis of silicosis is based on the history of exposure to silica dust associated with the radiological alterations compatible with the disease. With the main objective of comparing the alterations found in the chest radiography to those of high resolution computed tomography 49 patients with silicosis were selected. These imaging methods were evaluated separately by three readers and the results summarized through the median of the readings. The following alterations were analysed: nodules, coalescences, large opacities, lynfadenopathy. The patients were male, at an average age of 47.1 years, the majority being sandblasters, with an average exposure time to dust of 15.3 years. When the chest radiography was compared to high resolution computed tomography the following alterations were observed: i) the high resolution computed tomography showed greater profusion of nodules in 19 cases; ii) the high resolution computed tomography detected isolated coalescence and large opacities in 28 cases, seven of them who were classified initially as having simple silicosis were later changed to the complicated form; iii) the high resolution computed tomography was superior in the evaluation of lynfadenopathy in 16 cases. So, from the 49 analysed patients the high resolution computed tomography was more sensitive than the chest radiography in the evaluation of the alterations studied in 38 (77,5%) cases. Other alterations such as cavities, pleural thickening and emphysema were also observed only by this method in 5 cases. In the last 6 (12,2%) cases the high resolution computed tomography did not add any data when compared to chest radiography, four of these showed the initial form of the disease.

Adult↗
PubMed2002

Learning by computer simulation does not lead to better test performance than textbook study in the diagnosis and treatment of dysrhythmias.

STUDY OBJECTIVE: To compare computer-based learning with traditional learning methods in studying advanced cardiac life support (ACLS). DESIGN: Prospective, randomized study. SETTING: University hospital. MEASUREMENTS: Senior medical students were randomized to perform computer simulation and textbook study. Each group studied ACLS for 150 minutes. Tests were performed 1 week before, immediately after, and 1 week after the study period. Testing consisted of 20 questions. All questions were formulated in such a way that there was a single best answer. Each student also completed a questionnaire designed to assess computer skills, as well as satisfaction with and benefit from the study materials. MAIN RESULTS: Test scores improved after both textbook study and computer simulation study in both groups, although the improvement in scores was significantly higher for the textbook group only immediately after the study. There was no significant difference between groups in their computer skill and satisfaction with the study materials. The textbook group reported greater benefit from study materials than did the computer simulation group. CONCLUSIONS: Studying ACLS with a hard-copy textbook may be more effective than computer simulation for acquiring simple information during a brief period. However, the difference in effectiveness is likely transient.

Adult↗
PubMed2003

Automated centerline for computed tomography colonography.

RATIONALE AND OBJECTIVES: A novel method to compute the centerline of the human colon obtained from computed tomography colonography is proposed. Two applications of this method are demonstrated: to compute local colonic distension (caliber), and to match polyps on supine and prone images. MATERIALS AND METHODS: The centerline algorithm involves multiple steps including simplification of the colonic surface by decimation; thinning of the decimated colon to create a preliminary centerline; selection of equally spaced points on the preliminary centerline; grouping neighboring points; and mapping them back to rings in the original colon. This method was tested on 20 human computed tomography colonography datasets (supine and prone examinations of 10 patients) and on a computer-generated colon phantom. RESULTS: Visual inspection of the colons and their centerlines showed the centerline to be accurate. For the colon phantom, the average error was only 1 mm. For 11 polyps visualized in both the supine and prone positions and found by computer-aided detection, the normalized distance along the centerline to each polyp was not significantly different on the supine and prone views (r = 0.999; P < .001). CONCLUSION: This method produces an accurate colon centerline that may be useful for flight path planning, matching detections on the supine and prone views, and computing local colonic distension.

Algorithms↗
PubMed2004

Performance of computer-aided diagnosis in the interpretation of lesions on breast sonography.

RATIONALE AND OBJECTIVES: To investigate the potential usefulness of computer-aided diagnosis as a tool for radiologists in the characterization and classification of mass lesions on ultrasound. MATERIALS AND METHODS: Previously, a computerized method for the automatic classification of breast lesions on ultrasound was developed. The computerized method includes automatic segmentation of the lesion from the ultrasound image background and automatic extraction of four features related to lesion shape, margin, texture, and posterior acoustic behavior. In this study, the effectiveness of the computer output as an aid to radiologists in their ability to distinguish between malignant and benign lesions, and in their patient management decisions in terms of biopsy recommendation are evaluated. Six expert mammographers and six radiologists in private practice at an institution accredited by the American Ultrasound Institute of Medicine participated in the study. Each observer first interpreted 25 training cases with feedback of biopsy results, and then interpreted 110 additional ultrasound cases without feedback. Simulating an actual clinical setting, the 110 cases were unknown to both the observers and the computer. During interpretation, observers gave their confidence that the lesion was malignant and also their patient management recommendation (biopsy or follow-up). The computer output was then displayed, and observers again gave their confidence that the lesion was malignant and theirpatient management recommendation. Statistical analyses included receiver operator characteristic analysis and Student t-test. RESULTS: For the expert mammographers and for the community radiologists, the Az (area under the receiver operator characteristic curve) increased from 0.83 to 0.87 (P = .02) and from 0.80 to 0.84 (P = .04), respectively, when the computer aid was used in the interpretation of the ultrasound images. Also, the Az values for the community radiologists with aid and for the expert mammographers without aid are similar to the Az value for the computer alone (Az = 0.83). CONCLUSION: Computer analysis of ultrasound images of breast lesions has been shown to improve the diagnostic accuracy of radiologists in the task of distinguishing between malignant and benign breast lesions and in recommending cases for biopsy.

Biopsy↗
PubMed1996

Computed radiography X-ray exposure trends.

RATIONALE AND OBJECTIVES: Computed radiography provides correct optical density on film, independent of the incident radiation exposure, but it can result in under- or overexposure of the imaging plate. In the current study, we evaluated the radiation exposure trends of computed radiography over a 2-year period for portable chest examinations to determine and compare the radiographic techniques of the computed radiography system relative to conventional screen-film detectors. METHODS: A Fuji computed radiography system was interfaced to a digital workstation to track system usage and examination demographics, including examination type and sensitivity number. Hard-copy films were used for diagnosis. The sensitivity number, a value inversely related to incident exposure on the imaging plate, was used to determine whether the proper techniques were used by the technologists. RESULTS: The initial use of the computed radiography system revealed a broad distribution of exposures being used; complaints regarding noisy films (e.g., underexposure) resulted in subsequent overexposure for a significant number of films. A quality-control audit indicating excessive exposure resulted in educational feedback and a tighter distribution of exposures within the optimal range as determined by our radiologists. The average technique was approximately equivalent to a 200-speed system. CONCLUSION: Computed radiography provides excellent dynamic range and rescaling capabilities for proper film optical density, and thus fewer repeat examinations. However, underexposure results in suboptimal image quality that is related to excessive quantum mottle. Overexposure requires film audits to limit unnecessary radiation exposure. In general, the optimal exposures are achieved with approximately 1.5-2 times the incident detector exposure of a 400-speed rare-earth system. The ability of computed radiography to reduce radiation exposure is unlikely when compared with a typical rare-earth screen-film combination (400 speed) in terms of adequate image quality for the diagnosis of subtle, low-contrast findings. For certain diagnostic procedures (e.g., nasogastric tube placement verification), lower exposures can be tolerated.

Humans↗
PubMed1999

So, you are buying your first computer.

Buying your first computer need not be that complicated. The first thing that is needed is an understanding of what you want and need the computer for. By making a list of the various essentials, you will be on your way to purchasing that computer. Once that is completed, you will need an understanding of what each of the components of the computer is, how it works, and what options you have. This way, you will be better able to discuss your needs with the salesperson. The focus of this article is limited to personal computers or PCs (i.e., IBMs [Armonk, NY], IBM clones, Compaq [Houston, TX], Gateway [North Sioux City, SD], and so on). I am not including Macintosh or Apple [Cupertino, CA] in this discussion; most software is often made exclusively for personal computers or at least on the market for personal computers before becoming available in Macintosh version.

Computer Systems↗
PubMed2003

Relationship between carpal tunnel syndrome and wrist angle in computer workers.

Carpal tunnel syndrome (CTS) is the most widely known entrapment neuropathy. The aim of this study was to assess the incidence of CTS in a group of computer workers by typical symptoms, median nerve conduction studies, and their combinations. The posture of extended wrists while typing on a computer keyboard seems to be a predisposing factor for CTS. However, the correlation between wrist extension angle and the incidence of CTS is not well known. Forty-five subjects (mean age, 38.8 +/- 7.8 years) who used a computer for more than 6 hours daily in a medical center in southern Taiwan were studied. All completed questionnaires to ascertain their age, employment duration, dominant hand, and the severity of symptoms. Physical examinations (Tinel's sign and Phalen's test) were performed by a physician. The maximal wrist extension angle when typing on a computer keyboard was also measured by the same physician. Nerve conduction studies were performed on each subject to determine the severity of CTS. Results showed that the incidence of CTS in the computer workers was 16.7% (15 of 90 hands). Twelve subjects showed electrodiagnostic evidence of CTS: it involved the dominant hand in seven, the non-dominant hand in two, and bilateral hands in three. The severity of clinical symptoms was compatible with the findings of the nerve conduction studies. Among the major predisposing factors, we found significant correlation between CTS development and the wrist extension angle while typing on a computer keyboard. Computer workers who kept their wrists extended by more than 20 degrees were at greater risk of developing CTS.

Adult↗
PubMedDate not supplied

Applications of computers to toxicological research.

Computers are used in toxicology in two ways. They are able to manage and manipulate large amounts of data, and it is because of this that they are used quite commonly to search toxicity databases. The mechanical ability of computers has led a number of organizations to pursue their use in regulatory compliance. The cost-benefit aspect of this issue being what it is, much more effort can be expected in this area. The other major use of computers has been to support efforts to predict or estimate toxicity properties. This task has proven to be very difficult, as was expected, and progress has been mixed. Developers of systems, testing their own development, report impressive accuracy, as has been seen. The "real world" view is less felicitous. In a highly publicized, head-to-head test of some of the computer methods against human experts, accurate prediction of carcinogenicity by computer was achieved for 49-59% of the compounds, depending upon the method used. The humans, on the other hand, scored between 65% and 84%. A conclusion that could be drawn from this experiment is that with compounds which "obviously" are or are not carcinogenic, both computers and humans score well. Once obviousness recedes however, both are at a disadvantage, but humans can improvise more effectively. As research continues, the computer methods will develop better learning sets, and so there will be incremental improvements in their performance.(ABSTRACT TRUNCATED AT 250 WORDS)

Computers↗
PubMed1999

Dutch research into the development and impact of computer-tailored nutrition education.

OBJECTIVE: The aim of the present paper is to describe the essential elements of computer-tailored nutrition education and to study the impact of written computer-tailored nutrition education in comparison to general written nutrition advice. DESIGN: The impact of computer-tailored nutrition education was studied in three randomised trials as compared to general nutrition education. The data of the three studies were taken together and re-analysed. SUBJECTS: Random samples of employees at two work sites and a self-selected sample of the Dutch adult population. The total number of subjects was 1309. Response rates were between 45% in one of the work sites and 88% in the self-selected sample. INTERVENTIONS: Subjects in the experimental condition received computer-tailored nutrition education. With computer-tailoring, expert individualised nutrition education can be realised through an automated process for relatively large target groups with relatively low costs per person. MAIN OUTCOME MEASURES: The impact on changes in fat intake were studied. The use and appreciation of the intervention was also assessed. RESULTS: Subjects who received computer-tailored advice had a lower mean fat score at post-test, adjusted for baseline intake levels. Subjects who received tailored advice were more likely to have read and discussed the nutrition advice. CONCLUSION: The results point to the conclusion that printed computer-tailored nutrition education is superior to general written nutrition education.

Adult↗
PubMed1994

Electronic verification of donor-recipient compatibility: the computer crossmatch.

BACKGROUND: This article describes standard operating procedures (SOPs) for a computer crossmatch to replace the immediate-spin crossmatch for ABO incompatibility between patient blood samples submitted for pretransfusion testing and the blood component selected for transfusion. These SOPs were developed following recent changes to the Standards for Blood Banks and Transfusion Services of the American Association of Blood Banks (AABB). STUDY DESIGN AND METHODS: SOPs were developed, utilizing currently available software, for pretransfusion testing. The SOP for donor unit processing entails bar code entry of the unit number, component name, and ABO/Rh type; computer entry and interpretation of serologic reactions; warning of discrepancies between bar code-entered blood type and result interpretation; and quarantine of the donor unit in such instances. The SOP for patient sample testing requires bar code entry of specimen accession number, which accesses patient demographics; computer entry and interpretation of ABO/Rh tests; repeat blood typing at the time of crossmatch if only one patient blood type is on record; and warning if there are nonconcordant current and historical blood types. The computer crossmatch SOP requires bar code entry of specimen accession and donor unit numbers; release of group O red cells pending resolution of discrepancies; and immediate-spin crossmatch during computer downtime. Tables validated on-site prompt warning messages and prevent both computer crossmatch and release if blood components of the wrong ABO type are selected. RESULTS: These SOPs meet the requirements of the 15th edition of the AABB Standards. Projected annual time savings at this institution are > 100,000 workload recording units. Further benefits include reduced patient sample volume requirements, less handling of biohazardous material, and elimination of unwanted positive or negative reactions associated with the immediate-spin crossmatch. Release of incompatible blood components when the wrong patient blood type is on record is addressed by requiring the use of group O red cells in the absence of two concordant blood types, one of which must be from a current sample. CONCLUSION: A combination of existing computer programs and carefully developed SOPs can provide a safe and efficient means of detecting donor-recipient incompatibility without performance of serologic crossmatch.

ABO Blood-Group System↗
PubMed2005

Algorithmic approaches for computing elementary modes in large biochemical reaction networks.

The concept of elementary (flux) modes provides a rigorous description of pathways in metabolic networks and proved to be valuable in a number of applications. However, the computation of elementary modes is a hard computational task that gave rise to several variants of algorithms during the last years. This work brings substantial progresses to this issue. The authors start with a brief review of results obtained from previous work regarding (a) a unified framework for elementary-mode computation, (b) network compression and redundancy removal and (c) the binary approach by which elementary modes are determined as binary patterns reducing the memory demand drastically without loss of speed. Then the authors will address herein further issues. First, a new way to perform the elementarity tests required during the computation of elementary modes which empirically improves significantly the computation time in large networks is proposed. Second, a method to compute only those elementary modes where certain reactions are involved is derived. Relying on this method, a promising approach for computing EMs in a completely distributed manner by decomposing the full problem in arbitrarity many sub-tasks is presented. The new methods have been implemented in the freely available software tools FluxAnalyzer and Metatool and benchmark tests in realistic networks emphasise the potential of our proposed algorithms.

Algorithms↗
PubMed2002

Accuracy of computer-assisted radiographic measurement of interproximal bone loss in vertical bone defects.

Objective. The objective of the present study was to compare 2 different computer-assisted analysis systems with respect to the measurement of interproximal bone loss on radiographs. Study Design. In 14 patients with untreated advanced periodontal disease, 90 standardized radiographs were taken presurgically and during postoperative follow-up. During periodontal surgery for 30 vertical bone defects and 28 adjacent sites (22 vertical, 3 horizontal, and 3 without bone loss), the distances from the cementoenamel junction (CEJ) to the alveolar crest (AC) and from the CEJ to the bottom of bony defect (BD) were measured. In all radiographs, the linear distances from the CEJ to the AC and from the CEJ to BD were assessed by using 2 computer-assisted analysis devices: linear measurement (LMSRT) and FRIACOM (FRIADENT, Mannheim, Germany). A comparison between the radiographic and intrasurgical assessments was performed by using the paired t test. Results. With respect to the linear distance from the CEJ to the BD, the study failed to detect statistically significant differences between the computer-assisted techniques and intrasurgical measurement as the gold standard (LMSRT,: 0.26 +/- 2.16 mm [P >.05]; FRIACOM, 0.35 +/- 2.5 mm [P >.05]). In terms of the distance from the CEJ to the BD and from the CEJ to the AC, the correlation between both computer-assisted methods was excellent (r(s) > or = 0.75) and there were no statistically significant differences detectable between LMSRT and FRIACOM for both distances. With regard to the distance from the CEJ to the AC, both techniques overestimated interproximal bone loss as compared with intrasurgical measurements (CEJ-AC, LMSRT: 1.63 +/- 2.52 mm [P <.01]; FRIACOM: 2.00 +/- 2.48 mm [P <.01]). The amount of overestimation of interproximal bone loss did not differ significantly in either computer-assisted technique (P >.05). For double measurements, both LMSRT and FRIACOM showed excellent reproducibility with coefficients of variation that ranged between 3.8% and 4.5% (CEJ-BD) and between 5.7% and 6.6% (CEJ-AC). There were no statistically significant differences between the reproducibilities of both computer-assisted techniques (P <.05). Conclusions. Both LMSRT and FRIACOM are reproducible methods to measure the distances from the CEJ to the BD and from the CEJ to the AC on radiographs and can be recommended for clinical use. With respect to the distance from the CEJ to the AC, it must be kept in mind that both computer-assisted methods tend to overestimate the real distance on an average of 1.5 to 2.0 mm.

Adult↗