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PubMed1996

Evaluation of hydrocephalic periventricular radiolucency by dynamic computed tomography and xenon-computed tomography.

OBJECTIVE: A common finding of computed tomography in a case of normal-pressure hydrocephalus (NPH) is periventricular radiolucency (PVL). We analyzed PVL for patients with hydrocephalus, using dynamic computed tomographic and xenon-computed tomographic techniques to differentiate NPH from similar diseases. METHODS: Dynamic computed tomography was evaluated as a method of diagnosing NPH in 14 patients with computed tomographic findings of both PVL and ventricular dilatation. Of the 14 patients, varying degrees of clinical improvement after shunt surgery were observed in 10 (shunt-effective group) but not in the remaining 4 (shunt-ineffective group). The difference in arrival time between PVL and thalamus, the difference in peak time between PVL and anterior cerebral artery, and cerebral blood flow in PVL by xenon-computed tomographic study were analyzed. RESULTS: The difference in arrival time between PVL and thalamus was significantly longer in the effective group than among the remaining patients. There was no significant difference in PVL/cerebral blood flow and the difference in peak time between PVL and the anterior cerebral artery between the two groups. CONCLUSION: Dynamic computed tomographic analysis of the difference in arrival time between PVL and thalamus is useful for diagnosing NPH and predicting response to shunting.

Aged↗

PubMed2004

Adapting the human-computer interface for reading literacy and computer skill to facilitate collection of information directly from patients.

Clinical information collected directly from patients is critical to the practice of medicine. Past efforts to collect this information using computers have had limited utility because these efforts required users to be facile with the computerized information collecting system. In this paper we describe the design, development, and function of a computer system that uses recent technology to overcome the limitations of previous computer-based data collection tools by adapting the human-computer interface to the native language, reading literacy, and computer skills of the user. Specifically, our system uses a numerical representation of question content, multimedia, and touch screen technology to adapt the computer interface to the native language, reading literacy, and computer literacy of the user. In addition, the system supports health literacy needs throughout the data collection session and provides contextually relevant disease-specific education to users based on their responses to the questions. The system has been successfully used in an academically affiliated family medicine clinic and in an indigent adult medicine clinic.

Computer Literacy↗

PubMedDate not supplied

Computer-based medical system for the computation of blood pressure excess in the diagnosis of hypertension.

A computer-based system for assessing hypertension was designed by combining hardware for automatic, long-term blood pressure (BP) measurement with a set of software modules for computing time-specified tolerance intervals and evaluating measures of BP excess. BP is so variable that the identification and proper definition of hypertension are highly ambiguous when based on single measurements. One first step in dealing with such variability is to replace the constant limits for BP frequently used in the assessment of hypertension by a time-specified reference interval. Once such a threshold is available, a hyperbaric index can be computed by numerical integration as the total area (within one cycle) of any given patient's BP above the threshold. In order to examine the extent of normal physiologic excess, a series of 266 systolic and diastolic BP and heart rate (HR) measurements were automatically monitored every 30 minutes for at least 48 hours from clinically healthy subjects, aged 19 to 25 years. Original data were used to obtain 90% tolerance intervals for each gender separately. The hyperbaric index was then computed for each individual BP profile. The distribution of the maximum hyperbaric index (maximum of the values computed for systolic, mean arterial, and diastolic BP levels shows a highest value of 14.839 mmHg x hr for the men and of 10.229 mmHg x hr for the women. These values represent a testable threshold for assessing hypertension based on the proposed approach. The tolerance intervals obtained from the reference population were also used to compute hyperbaric indices for a series of 175 BP measurements sampled from clinically healthy people, as well as a series of 60 measurements sampled from patients with mild hypertension. Sensitivity and specificity in the diagnosis of hypertension based on the hyperbaric index were both 100%, as opposed to values obtained from computing the BP load, the average of the BP series, or the circadian amplitude, all of which provided a much poorer diagnostic test. The software system developed for automatically establishing time-qualified tolerance limits from a reference population and assessing the extent and timing of BP elevation for a test subject may help to establish a prognosis and diagnosis, with a correspondingly better assessment of health status, to initiate treatment if needed, to time treatment when it is most desirable and least harmful in terms of undesired effects, and to gauge the patient's response to treatment.

Adult↗

PubMedDate not supplied

An evaluation method of computer usability based on human-to-computer information transmission model.

This paper proposes a new evaluation and prediction method for computer usability. This method is based on our two previously proposed information transmission measures created from a human-to-computer information transmission model. The model has three information transmission levels: the device, software, and task content levels. Two measures, called the device independent information measure (DI) and the computer independent information measure (CI), defined on the software and task content levels respectively, are given as the amount of information transmitted. Two information transmission rates are defined as DI/T and CI/T, where T is the task completion time: the device independent information transmission rate (RDI), and the computer independent information transmission rate (RCI). The method utilizes the RDI and RCI rates to evaluate relatively the usability of software and device operations on different computer systems. Experiments using three different systems, in this case a graphical information input task, confirm that the method offers an efficient way of determining computer usability.

Computer Literacy↗

PubMed2006

On teaching computer ethics within a computer science department.

The author has surveyed a quarter of the accredited undergraduate computer science programs in the United States. More than half of these programs offer a 'social and ethical implications of computing' course taught by a computer science faculty member, and there appears to be a trend toward teaching ethics classes within computer science departments. Although the decision to create an 'in house' computer ethics course may sometimes be a pragmatic response to pressure from the accreditation agency, this paper argues that teaching ethics within a computer science department can provide students and faculty members with numerous benefits. The paper lists topics that can be covered in a computer ethics course and offers some practical suggestions for making the course successful.

Computers↗

PubMed1998

Medical affective computing: medical informatics meets affective computing.

"The need to cope with a changing and partly unpredictable world makes it very likely that any intelligent system with multiple motives and limited powers will have emotions." [1] From advisory systems that understand emotional attitudes toward medical outcomes, to wearable computers that compensate for communication disability, to computer simulations of emotions and their disorders, the research agendas of medical informatics and affective computing--how and why to create computers that detect, convey, and even have emotions--increasingly overlap. Some psychiatric and neurological researchers state their theories in terms of actual or hypothetical computer programs. Adaptive intelligent systems will increasingly rely on emotions to compensate for their own conflicting goals and limited resources--emotional reactions about which psychiatrists and neurologists have special insights. DEP2 (Depression Emulation Program 2) is a computer simulation of adaptive depression--learning from explainable patterns of failure in autobiographical memory--that simulates many depressive behaviors. In the terminology of fault-tolerant computing, adaptive depression involves fault detection (triggered by failure), fault location (strategic retreat and failure diagnosis), and fault recovery (return to on-line operation). DEP2 relies on subsystems whose structures and behaviors are based on popular hypotheses about left and right brain hemispheric function during depression and emotion. DEP2 and its predecessors, DEP and DEPlanner, are relevant to psychiatric and neurological informatics, and to the design of adaptive autonomous robots and software agents.

Adaptation, Psychological↗

PubMed1999

Computed tomographic angiography: historical perspective and new state-of-the-art using multi detector-row helical computed tomography.

Since its clinical introduction in 1991, volumetric computed tomography scanning using spiral or helical scanners has resulted in a revolution for diagnostic imaging. In addition to new applications for computed tomography, such as computed tomographic angiography and the assessment of patients with renal colic, many routine applications such as the detection of lung and liver lesions have substantially improved. Helical computed tomographic technology has improved over the past eight years with faster gantry rotation, more powerful X-ray tubes, and improved interpolation algorithms, but the greatest advance has been the recent introduction of multi detector-row computed tomography scanners. These scanners provide similar scan quality at a speed gain of 3-6 times greater than single detector-row computed tomography scanners. This has a profound impact on the performance of computed tomography angiography, resulting in greater anatomic coverage, lower iodinated contrast doses, and higher spatial resolution scans than single detector-row systems.

Angiography↗

PubMed2003

Evaluation of a tool to categorize patients by reading literacy and computer skill to facilitate the computer-administered patient interview.

Past efforts to collect clinical information directly from patients using computers have had limited utility because these efforts required users to be literate and facile with the computerized information collecting system. In this paper we describe the creation and use of a computer-based tool designed to assess a user's reading literacy and computer skill for the purpose of adapting the human-computer interface to fit the identified skill levels of the user. The tool is constructed from a regression model based on 4 questions that we identified in a laboratory study to be highly predictive of reading literacy and 2 questions predictive of computer skill. When used in 2 diverse clinical practices the tool categorized low literacy users so that they received appropriate support to enter data through the computer, enabling them to perform as well as high literacy users. Confirmation of the performance of the tool with a validated reading assessment instrument showed a statistically significant difference (p=0.0025) between the two levels of reading literacy defined by the tool. Our assessment tool can be administered through a computer in less than two minutes without requiring any special training or expertise making it useful for rapidly determining users' aptitudes.

Computer Literacy↗

PubMed1985

[Computers in radiology. Adjustment to new competitive situations through use of computers with user-specific software].

With this publication, the author presents the requirements that a user specific software should fulfill to reach an effective practice rationalisation through computer usage and the hardware configuration necessary as basic equipment. This should make it more difficult in the future for sales representatives to sell radiologists unusable computer systems. Furthermore, questions shall be answered that were asked by computer interested radiologists during the system presentation. On the one hand there still exists a prejudice against programmes of standard texts and on the other side undefined fears, that handling a computer is to difficult and that one has to learn a computer language first to be able to work with computers. Finally, it is pointed out, the real competitive advantages can be obtained through computer usage.

Computers↗

PubMedDate not supplied

Computer attitude and computer anxiety in nursing. Validation of an instrument using an Australian sample.

The purpose of this study was to refine the instrument, Nurses' Computer Attitudes Inventory (NCATT), which was developed to measure nurses' attitudes toward computers in an Australian setting. The study was designed to test the reliability and validity (concurrent and discriminant) of the instrument. The NCATT was administered to 170 subjects: 71 first-year nursing students and 99 nurses employed in a local hospital. On the basis of factor and item analysis the 40-item NCATT was reduced to 22 items. Three factors for the revised NCATT were identified: (1) Computers and Patient Care, (2) Computer Anxiety, and (3) Patient Confidentiality and Computers. These three factors accounted for 90.0% of the variance (factor 1, 56.6%; factor 2, 24.8%; and factor 3, 8.6%). The factors demonstrated good internal consistency with the Cronbach alpha coefficients for each factor ranging from 0.72 to 0.90. The revised NCATT provided evidence of concurrent validity on the student sample when related to Dambrodt's scale for Computer Attitudes. Some evidence of discriminant validity was demonstrated as the internal consistency reliabilities were much higher in all factors than their intercorrelations. The authors propose that the revised NCATT is a practical instrument that is useful to assess nurses' attitudes before computer implementation and training.

Anxiety↗

PubMed1997

High-performance computing and networking as tools for accurate emission computed tomography reconstruction.

It is well known that the quantitative potential of emission computed tomography (ECT) relies on the ability to compensate for resolution, attenuation and scatter effects. Reconstruction algorithms which are able to take these effects into account are highly demanding in terms of computing resources. The reported work aimed to investigate the use of a parallel high-performance computing platform for ECT reconstruction taking into account an accurate model of the acquisition of single-photon emission tomographic (SPET) data. An iterative algorithm with an accurate model of the variable system response was ported on the MIMD (Multiple Instruction Multiple Data) parallel architecture of a 64-node Cray T3D massively parallel computer. The system was organized to make it easily accessible even from low-cost PC-based workstations through standard TCP/IP networking. A complete brain study of 30 (64x64) slices could be reconstructed from a set of 90 (64x64) projections with ten iterations of the conjugate gradients algorithm in 9 s, corresponding to an actual speed-up factor of 135. This work demonstrated the possibility of exploiting remote high-performance computing and networking resources from hospital sites by means of low-cost workstations using standard communication protocols without particular problems for routine use. The achievable speed-up factors allow the assessment of the clinical benefit of advanced reconstruction techniques which require a heavy computational burden for the compensation effects such as variable spatial resolution, scatter and attenuation. The possibility of using the same software on the same hardware platform with data acquired in different laboratories with various kinds of SPET instrumentation is appealing for software quality control and for the evaluation of the clinical impact of the reconstruction methods.

Algorithms↗

PubMed1993

Increased single-photon emission computed tomography image processing speed achieved in personal computers with memory-intensive algorithms.

Recent dramatic reductions in the cost of computer random access memory (RAM) and the ability of newer microprocessors and associated personal computer operating systems to address large amounts of memory make novel strategies for high-speed image processing possible. We developed image processing algorithms that use this newly available memory to achieve increases in effective processing speed. These algorithms rely on the use of precomputed lookup tables to avoid repeated use of relatively expensive machine instructions, such as multiplications and divisions. Programs using this strategy to perform single photon emission computer tomography (SPECT) analysis were written in C and assembly language and tested on a Macintosh Quadra 950 (Apple Computer, Cupertino, CA) having 64 megabytes of RAM. The measured processing times are competitive with most dedicated nuclear medicine computers. A general implementation of such programs will allow personal computers to compete with dedicated imaging systems, at a substantial reduction in cost.

Algorithms↗

PubMed2005

A computer-simulated liver phantom (virtual liver phantom) for multidetector computed tomography evaluation.

OBJECTIVE: The purpose of study was to develop a computer-simulated liver phantom for hepatic CT studies. A computer-simulated liver phantom was mathematically constructed on a computer workstation. MATERIALS AND METHODS: The computer-simulated phantom was calibrated using real CT images acquired by an actual four-detector CT. We added an inhomogeneous texture to the simulated liver by referring to CT images of chronically damaged human livers. The mean CT number of the simulated liver was 60 HU and we added numerous 5-to 10-mm structures with 60+/-10 HU/mm. To mimic liver tumors we added nodules measuring 8, 10, and 12 mm in diameter with CT numbers of 60+/-10, 60+/-15, and 60+/-20 HU. Five radiologists visually evaluated similarity of the texture of the computer-simulated liver phantom and a real human liver to confirm the appropriateness of the virtual liver images using a five-point scale. RESULTS: The total score was 44 in two radiologists, and 42, 41, and 39 in one radiologist each. They evaluated that the textures of virtual liver were comparable to those of human liver. CONCLUSIONS: Our computer-simulated liver phantom is a promising tool for the evaluation of the image quality and diagnostic performance of hepatic CT imaging.

Computer Simulation↗

PubMed2004

Mixture distribution analysis of a computer assisted diagnostic method for the evaluation of pulmonary nodules on computed tomography scan.

RATIONALE AND OBJECTIVES: To compare the effectiveness of a new computational scheme for pulmonary nodule detection in computed tomography images against human observers. MATERIALS AND METHODS: The study involved evaluation of 81 potential nodules by four radiologists. Each radiologist separately evaluated the potential nodules and provided a confidence level for the presence of pulmonary nodules. Their performance was compared with that of the new computational scheme by mixture distribution analysis. RESULTS: Mixture distribution analysis of the results of the four radiologists demonstrated a relative proportion agreement of 0.84. The kappa statistic was used to compare the agreement of the computational scheme with the results of the four radiologists. A kappa value of .65 (se = .11) was shown to be significantly different from chance (P = .99). CONCLUSION: The new computational scheme correlates well with the radiologists' subjective rankings of pulmonary nodules on computed tomography scans and may prove a useful tool in the evaluation of algorithms for the screening and diagnosis of lung cancer.

Humans↗

PubMed2002

Assessment of emergency medicine residents' computer knowledge and computer skills: time for an upgrade?

OBJECTIVE: To describe emergency medicine residents' (EMRs') personal computer (PC) use and educational needs and to compare their perceived and actual PC skills. METHODS: This was a prospective, cross-sectional study. Subjects were all EMRs at seven midwestern Accreditation Council for Graduate Medical Education (ACGME) residency programs. The EMRs completed a questionnaire about their PC use and ability to perform 23 tasks derived from two national retail-training programs. The tasks covered word processing, slide making, and Internet use. The EMRs then took a three-part test performing the skills in the questionnaire. Two independent raters scored the tests. Frequencies with 95% confidence intervals (95% CIs) were calculated for categorical data. Positive and negative predictive values were used to report information comparing residents' performance with their self-assessment of skills. Cohen's kappa was used to test agreement between raters. RESULTS: One hundred twenty-four of 158 (79%) eligible EMRs participated. Since not all participants engaged in all parts of the study, the sample size varies between 121 and 124. One hundred one of 122 (83%; 95% CI = 75 to 89) owned a PC. The EMRs use home PCs a mean of 3.8 hours/week for physician duties and use residency PCs 1.9 hours/week (range 0-20). Ninety-six of 122 (79%; 95% CI = 70 to 86) EMRs reported no formal PC training during residency. Thirty-five percent (43/122; 95% CI = 27 to 44) passed the word-processing test and 50% (62/123; 95% CI = 41 to 60) passed the slide-making test. Reasons for failure were because of errors and not having a presentable product. Thirty-eight of 122 (31%; 95% CI = 23 to 40) failed the literature search, including 33 who said they could perform it. One hundred fifteen of 123 (94%; 95% CI = 88 to 98) EMRs were able to find an Internet address, including ten who stated they could not. Twenty-one percent of the residents who attempted any test (26/124; 95% CI = 14 to 29) passed all three tests. There was no association between year of training and success on the tests (p = 0.374). Thirty-seven of 115 (32%; 95% CI = 24 to 42) EMRs said they had insufficient PC training to meet their physician needs. CONCLUSIONS: Emergency medicine residents have much access to computer technology and possess some computer skills; however, many are unable to produce a usable product or conduct a literature search. Emergency medicine residents have not had sufficient computer training prior to residency. The computer skills of EMRs should be assessed through skills testing rather than self-assessment, and computer training during residency should be improved.

Computer Literacy↗

PubMed2002

Human-computer interaction: psychological aspects of the human use of computing.

Human-computer interaction (HCI) is a multidisciplinary field in which psychology and other social sciences unite with computer science and related technical fields with the goal of making computing systems that are both useful and usable. It is a blend of applied and basic research, both drawing from psychological research and contributing new ideas to it. New technologies continuously challenge HCI researchers with new options, as do the demands of new audiences and uses. A variety of usability methods have been developed that draw upon psychological principles. HCI research has expanded beyond its roots in the cognitive processes of individual users to include social and organizational processes involved in computer usage in real environments as well as the use of computers in collaboration. HCI researchers need to be mindful of the longer-term changes brought about by the use of computing in a variety of venues.

Attitude to Computers↗

PubMed1988

Measurement of intracranial tissue volume using computed tomographic images and a personal computer.

A software package called MacMeasure was developed previously to measure the size of intracellular structures by means of photomicrographs. We have expanded the application of this program to computed tomographic (CT) images. Using three objects of irregular shape and unequal size (phantoms), we compared volumetric determinations made with a CT mainframe computer and a widely available personal computer. The phantom objects were scanned in a GE CT/T 9800 scanner with serial, nonoverlapping slices 3.0 mm in thickness. The image data were first measured directly from the magnetic archive tape with the CT control terminal. Hard copies of the CT scans were then measured with a Macintosh SE computer and a digitizing tablet with a crosshair cursor driven by the MacMeasure software package. A third method of measuring volume was by tracing individual CT images onto paper (hard copies). The tracings were then cut out, weighed, and converted to surface area by dividing the weights by a weight/surface area standard (26.37 mg = 25 cm2) calibrated to the CT image scale (5.0 cm). The total surface area value was then converted to volume by multiplying by a single CT slice thickness (0.3 cm). Finally, the phantom objects were placed in water-filled graduated cylinders to determine their volume by fluid displacement. The technique using MacMeasure and the personal computer provides an accurate means of determining surface area and volumes using hard copies of CT images. It avoids occupying costly CT computer time and is the most rapid method of volume measurement of the three techniques tested (CT mainframe = 6.0 hours, trace/weigh = 3.5 hours, and PC = 1.25 hours).(ABSTRACT TRUNCATED AT 250 WORDS)

Brain Neoplasms↗

PubMedDate not supplied

Computational Science and Engineering Online (CSE-Online): a cyber-infrastructure for scientific computing.

With the expansion of the Internet and World Wide Web (or the Web), research environments have changed dramatically. As a result, the need to be able to efficiently and securely access information and resources from remote computer systems is becoming even more critical. This paper describes the development of an extendable integrated Web-accessible simulation environment for computational science and engineering called Computational Science and Engineering Online (CSE-Online; http://cse-online.net). CSE-Online is based on a unique client-server software architecture that can distribute the workload between the client and server computers in such a way as to minimize the communication between the client and server, thus making the environment less-sensitive to network instability. Furthermore, the new software architecture allows the user to access data and resources on one or more remote servers as well as on the computing grid while having the full capability of the Web-services collaborative environment. It can be accessed anytime and anywhere from a Web browser connected to the network by either a wired or wireless connection. It has different modes of operations to support different working environments and styles. CSE-Online is evolving into middleware that can provide a framework for accessing and managing remote data and resources including the computing grid for any domain, not necessarily just within computational science and engineering.

Engineering↗