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Comparison of diagnosis of early retinal lesions of diabetic retinopathy between a computer system and human experts.

OBJECTIVE: To investigate whether a computer vision system is comparable with humans in detecting early retinal lesions of diabetic retinopathy using color fundus photographs. METHODS: A computer system has been developed using image processing and pattern recognition techniques to detect early lesions of diabetic retinopathy (hemorrhages and microaneurysms, hard exudates, and cotton-wool spots). Color fundus photographs obtained from American Indians in Oklahoma were used in developing and testing the system. A set of 369 color fundus slides were used to train the computer system using 3 diagnostic categories: lesions present, questionable, or absent (Y/Q/N). A different set of 428 slides were used to test and evaluate the system, and its diagnostic results were compared with those of 2 human experts-the grader at the University of Wisconsin Fundus Photograph Reading Center (Madison) and a general ophthalmologist. The experiments included comparisons using 3 (Y/Q/N) and 2 diagnostic categories (Y/N) (questionable cases excluded in the latter). RESULTS: In the training phase, the agreement rates, sensitivity, and specificity in detecting the 3 lesions between the retinal specialist and the computer system were all above 90%. The kappa statistics were high (0.75-0.97), indicating excellent agreement between the specialist and the computer system. In the testing phase, the results obtained between the computer system and human experts were consistent with those of the training phase, and they were comparable with those between the human experts. CONCLUSIONS: The performance of the computer vision system in diagnosing early retinal lesions was comparable with that of human experts. Therefore, this mobile, electronically easily accessible, and noninvasive computer system, could become a mass screening tool and a clinical aid in diagnosing early lesions of diabetic retinopathy.

Aged↗

Computer classification of nonproliferative diabetic retinopathy.

OBJECTIVE: To propose methods for computer grading of the severity of 3 early lesions, namely, hemorrhages and microaneurysms, hard exudates, and cotton-wool spots, and classification of nonproliferative diabetic retinopathy (NPDR) based on these 3 types of lesions. METHODS: Using a computer diagnostic system developed earlier, the number of each of the 3 early lesions and the size of each lesion in the standard photographs were determined. Computer classification criteria were developed for the levels of individual lesions and for NPDR. Evaluation of the criteria was performed using 430 fundus images with normal retinas or any degree of retinopathy and 361 fundus images with no retinopathy or the 3 early lesions only. The results were compared with those of the graders at the University of Wisconsin Ocular Epidemiology Reading Center and an ophthalmologist. MAIN OUTCOME MEASURES: Agreement rates in the classification of NPDR between the computer system and human experts. RESULTS: In determining the severity levels of individual lesions, the agreement rates between the computer system and the reading center were 82.6%, 82.6%, and 88.3% using the 430 images and 85.3%, 87.5%, and 93.1% using the 361 images, respectively, for hemorrhages and microaneurysms, hard exudates, and cotton-wool spots. When the "questionable" category was excluded, the corresponding agreement rates were 86.5%, 92.3%, and 91.0% using the 430 images and 89.7%, 96.3%, and 97.4% using the 361 images. In classifying NPDR, the agreement rates between the computer system and the ophthalmologist were 81.7% using the 430 images and 83.5% using the 361 images. CONCLUSIONS: The proposed criteria for computer classification produced results that are comparable with those provided by human experts. With additional research, this computer system could become a useful clinical aid to physicians and a tool for screening, diagnosing, and classifying NPDR.

Aneurysm↗

A comparison of a lecture and computer program to teach fundamentals of the Draw-a-Person test.

BACKGROUND: Although computer-assisted education has been used to augment education in many areas, there are few studies of programs designed to replace lectures in a medical curriculum. OBJECTIVE: To test whether a thoughtfully designed computer program can replace a standard lecture in a pediatrics curriculum while teaching the subject matter equally well. METHODS: A computer program was developed to teach the Draw-a-Person developmental test using the multimedia-authoring tool Director. One of us (A.E.C.) tested and modified the program several times during its creation after submitting it to several objective evaluators. Thirty-nine students taking the clinical pediatrics rotation were chosen by month to interact with the program or attend the lecture. All students then scored 3 drawings and assigned them a developmental age according to the Draw-a-Person test rules. Students assigned to the computer program also completed a questionnaire evaluating the program in several subjective areas. A t test for 2 samples assuming equal variance was used to analyze the test results. RESULTS: Students receiving the lecture (control group) scored the 3 drawings as 5.43 years (age range, 4.5-8 years), 9.08 years (age range, 7-12 years), and 3.5 years (age range, 2-5 years), respectively. Those using the computer program (study group) scored the 3 drawings as 5.91 years (age range, 5-7 years), 7.68 years (age range, 7-8 years), and 4.34 years (age range, 3-5 years), respectively. The correct answers for the ages were 6, 7.75, and 4.25 years, respectively. A t test for 2 samples assuming equal variance showed that students using the computer program performed better on all 3 drawings (P<.05, P<.02, and P<.002, respectively). CONCLUSIONS: Students using the computer program were more accurate than students attending the lecture when scoring drawings and estimating a developmental age from them. These results support the conclusion that a thoughtfully designed computer program can replace a standard lecture in a pediatrics curriculum.

Attitude to Computers↗

MODEL-molecular descriptor lab: a web-based server for computing structural and physicochemical features of compounds.

Molecular descriptors represent structural and physicochemical features of compounds. They have been extensively used for developing statistical models, such as quantitative structure activity relationship (QSAR) and artificial neural networks (NN), for computer prediction of the pharmacodynamic, pharmacokinetic, or toxicological properties of compounds from their structure. While computer programs have been developed for computing molecular descriptors, there is a lack of a freely accessible one. We have developed a web-based server, MODEL (Molecular Descriptor Lab), for computing a comprehensive set of 3,778 molecular descriptors, which is significantly more than the approximately 1,600 molecular descriptors computed by other software. Our computational algorithms have been extensively tested and the computed molecular descriptors have been used in a number of published works of statistical models for predicting variety of pharmacodynamic, pharmacokinetic, and toxicological properties of compounds. Several testing studies on the computed molecular descriptors are discussed. MODEL is accessible at http://jing.cz3.nus.edu.sg/cgi-bin/model/model.cgi free of charge for academic use.

Amino Acids↗

A computer-controlled conformal radiotherapy system. II: Sequence processor.

PURPOSE: A sequence processor (SP) is described as part of a larger computer-controlled conformal radiotherapy system (CCRS). The SP provides the means to accept and then translate highly sophisticated radiation therapy treatment plans into vendor specific instructions to control treatment delivery on a computer-controlled treatment machine. METHODS AND MATERIALS: The sequence processor (SP) is a small workstation computer that interfaces to the control computer of computer-controlled treatment machines, and to other parts of the larger CCRS system. The system reported here has been interfaced to a computer-controlled racetrack microtron with two treatment gantries, and also to other linear accelerator treatment machines equipped with multileaf collimators. An extensive design process has been used in defining the role of the SP within the context of the larger CCRS project. Flexibility and integration with various components of the project, including databases, treatment planning system, graphical simulator, were key factors in the development. In conjunction with the planned set of treatment fields, a procedural scripting language is used to define the sequence of treatment events that are performed, including operator interactions, communications to other systems such as dosimetry and portal imaging devices, and database management. RESULTS: A flexible system has been developed to allow investigation into procedural steps required for simulating and delivering complex radiation treatments. The system has been used to automate portions of the acceptance testing for the control system of the microtron, and is used for routine daily quality assurance testing. The sequence processor system described here has been used to deliver all clinical treatments performed on the microtron system in 2 years of clinical treatment (more than 200 patients treated to a variety of treatment sites). CONCLUSIONS: The sequence processor system has enabled the delivery of complex treatment using computer-controlled treatment machines. The flexibility of the system allows integration with secondary devices and modification of procedural steps, making it possible to develop effective techniques for insuring safe and efficient computer-controlled conformal radiation therapy treatments.

Computer Simulation↗

Modification of surgical planning based on cardiac multidetector computed tomography in reoperative heart surgery.

BACKGROUND: Repeat open heart surgery is associated with an increased risk of injury to old conduits and cardiac structures. To reduce this risk, we evaluated the contribution of multidetector computed tomography angiography in planning repeat cardiac operations. METHODS: Fifteen patients who had previous coronary artery bypass grafting procedures underwent retrospective-gated computed tomographic angiography with a 16-slice multidetector computed tomography. Relation of the grafts to the expected median sternotomy line, graft patency and anatomic course, possible aortic cannulation and cross-clamp sites, distances between the right ventricle to the sternum, and calcification of the ascending aorta were assessed. RESULTS: Multidetector computed tomography demonstrated 45 conduits (mean, 3 +/- 1.1); 18 arterial grafts and 13 saphenous vein grafts that were patent, and 2 internal mammary artery grafts and 12 saphenous vein grafts that were occluded. Significant narrowing was shown in 3 of the patent internal mammary arteries and 4 of the patent saphenous vein grafts. Adherence of the right ventricle, left internal mammary artery, and saphenous vein graft to the sternum (0 to 3 mm in the midline) was demonstrated in 8, 2, and 1 patients, respectively. Two patients had a heavily calcified aorta. During surgery, all multidetector computed tomographic findings were confirmed. Three aspects of the operative plans of 4 patients were modified according to multidetector computed tomographic findings: median sternotomy approach (3 patients), cannulation site (2 patients), and myocardial preservation technique (3 patients). On the basis of multidetector computed tomographic evaluations, surgery was cancelled in 2 patients in whom repeat operation was judged to be associated with increased risk: 1 patient, scheduled for coronary artery bypass grafting, had an extremely calcified aorta, and the other, scheduled for aortic valve replacement, had grafts that were adherent to the sternum. CONCLUSIONS: Multidetector computed tomography is a new noninvasive tool for three-dimensional preoperative assessment of complex cardiac and graft anatomy. Our initial experience suggests that it may provide information to warrant modifying surgical planning, thus contributing to the safety of reoperative heart surgery.

Aged↗

Validation of a new protocol for computer-assisted evaluation of kinematics of double-bundle ACL reconstruction.

BACKGROUND: Computer-assisted surgery is useful to increase the precision of anterior cruciate ligament (ACL) surgical procedure, but could be even more important in evaluating the global performance of reconstructed ACL. This paper describes a new protocol for an accurate and extensive computer-assisted evaluation of single- and double-bundle reconstructions of ACL. METHODS: The protocol consists of the acquisition of the leg axes, ACL and graft insertions by a navigation system, and tracking of the knee motion during the classical kinematic test of knee stability. These data are elaborated by computer software in order to compute graft biomechanical behaviour and the knee kinematics and estimate the performance of the intervention. FINDINGS: The proposed protocol was validated on three cadaver knees. It resulted minimally invasive, effective to describe graft kinematic performance and able to provide a 3D reliable description of the reconstructed knee. INTERPRETATION: The protocol is an extension of the present evaluation of computer-assisted packages and includes additional kinematic tests and computations. The scientist-reader can find important details on tested computations to implement a similar computer-assisted procedure for new applications in knee surgery, while the surgeon can find in this procedure a means to improve the evaluation of ACL reconstruction and identify the residual laxity.

Anterior Cruciate Ligament↗

Computer-based learning for ESRD patient education: current status and future directions.

Computer use in everyday life has expanded human potential in virtually every possible arena. In health care, computer technology affects direct clinical care through diagnostics, treatment, monitoring, and documentation processes. Patient care systems use computer technology to manage billing, scheduling, and multiple other administrative functions. Computer technology for education of health care professionals has been primarily in selected undergraduate, graduate, and professional degree programs. Computer-based continuing education for health care professionals has been available for at least a decade, but computer-based patient education is just now beginning to emerge as a learning option. This article describes examples of patient education programs using different types of hardware and software and explores potential areas for further development of this area for end-stage renal disease patients and families. Computer technology is not a replacement for professional involvement in patient education, but rather offers a new arena of media to enhance and expand current teaching and learning resources. Computer-based learning is characterized by features representative of many highly regarded principles of adult education. Further, instructional design concepts used for program development are fundamentally sound for patient education.

Computer-Assisted Instruction↗

Use of student-centred, computer-mediated communication to enhance the medical school curriculum.

OBJECTIVES: While it is clear that computers will play an important role in the study and practice of medicine their introduction into the curriculum remains controversial. Computer purchase has been made compulsory for incoming students. DESIGN: Members of the incoming class were allowed to purchase any computer and modem capable of using the communication program chosen by the school. No formal computer training was given. Students were encouraged to call for assistance or bring in their computers for configuration. The primary object of the system was for communication between the students and between students and faculty. SETTING: The School of Medicine of the University of New Mexico. SUBJECTS: First-year medical students. RESULTS: The vast majority of students set up their computers and connected to the system with little assistance. At the end of the first week of studies all the students were connected. Most of the students used the system on a daily basis. The greatest interest was in discussions concerning examinations with 93% of students reading these postings. The least-used aspect of the system was the exchange of learning issues from small group case discussions. Students also downloaded the curricular material provided but were discriminating in accessing this content. CONCLUSIONS: The student use of the computer as a communication tool has been a success. Students used the system in a variety of ways and by so doing also learned the basics of computer use and maintenance. The area of faculty training is often ignored but is considered crucial to the success of such a project.

Computer Communication Networks↗

Advances in computer imaging/applications in facial plastic surgery.

Rapidly progressing computer technology, ever-increasing expectations of patients, and a confusing medicolegal environment requires a clarification of the role of computer imaging/applications. Advances in computer technology and its applications are reviewed. A brief historical discussion is included for perspective. Improvements in both hardware and software with the advent of digital imaging have allowed great increases in speed and accuracy in patient imaging. This facilitates doctor-patient communication and possibly realistic patient expectations. Patients seeking cosmetic surgery now often expect preoperative imaging. Although society in general has become more litigious, a literature search up to 1998 reveals no lawsuits directly involving computer imaging. It appears that conservative utilization of computer imaging by the facial plastic surgeon may actually reduce liability and promote communication. Recent advances have significantly enhanced the value of computer imaging in the practice of facial plastic surgery. These technological advances in computer imaging appear to contribute a useful technique for the practice of facial plastic surgery. Inclusion of computer imaging should be given serious consideration as an adjunct to clinical practice.

Analog-Digital Conversion↗

Physical workload during use of speech recognition and traditional computer input devices.

Musculoskeletal symptoms among computer users are frequently found. The aim was to investigate the musculoskeletal workload during computer work using speech recognition and traditional computer input devices (keyboard/mouse). Ten experienced computer users (nine female, one male) participated. They performed three different computer tasks: (1). text entry and (2). text editing of a standard text and (3). a self-selected work task. These tasks were performed twice using speech recognition and traditional computer input devices (keyboard/mouse). Additionally, a task consisting of reading aloud of the standard text was performed. Surface EMG from the forearm (m. extensor carpi ulnaris, m. extensor carpi radialis), the shoulder (m. trapezius) and the neck extensor muscles was recorded, in addition to the voice-related muscles (m. scalenii, m. cricothyroideus). Using speech recognition during text entry and text editing reduced the static muscle activity of the forearm, neck and to some extent the shoulder muscles. Furthermore, tendencies to longer periods of muscle activity pause (relative time with EMG gaps) in the forearm and shoulder muscles were found. This was seen at the expense of a tendency to an increased static activity and a decreased relative time with EMG gaps in m. cricothyroideus. Finally, during use of speech recognition the hand was tied to the keyboard/mouse for a shorter period of time, while the eyes were viewing the screen for a longer period of time compared to the condition with traditional computer input devices. It is recommended to use speech recognition as a supplementary tool to traditional computer input devices.

Computer Peripherals↗

Personal use of work computers: distraction versus destruction.

To explore definitions, frequencies, and motivation for personal use of work computers, we analyzed 329 employees' responses to an online survey, which asked participants to self-report frequencies for 41 computer behaviors at work. This sample (65% female, 74% European ethnicity, mean age of 36 years) was formed by soliciting participants through Internet Usenet groups, emails, and listservs. Results support a distinction between computer use that is counterproductive and that which is merely not productive. Nonproductive Computer Use occurred more when employees were younger (r = -0.31, p < 0.01), had Internet access at work longer (r = +0.16, p < 0.01), and had faster Internet connections at work than at home (r = +0.14, p < 0.01). Counterproductive Computer Use occurred more when Internet access was newer (r = -0.16, p < 0.01) and employees knew others who had been warned about misuse (r = +0.11, p < 0.05). While most employees who engaged in computer counterproductivity also engaged in computer nonproductivity, the inverse was uncommon, suggesting the need to distinguish between the two when establishing computer policies and Internet accessibility.

Adult↗

Advanced computing for systems biology.

Systems biology is based on computational modelling and simulation of large networks of interacting components. Models may be intended to capture processes, mechanisms, components and interactions at different levels of fidelity. Input data are often large and geographically disperse, and may require the computation to be moved to the data, not vice versa. In addition, complex system-level problems require collaboration across institutions and disciplines. Grid computing can offer robust, scaleable solutions for distributed data, compute and expertise. We illustrate some of the range of computational and data requirements in systems biology with three case studies: one requiring large computation but small data (orthologue mapping in comparative genomics), a second involving complex terabyte data (the Visible Cell project) and a third that is both computationally and data-intensive (simulations at multiple temporal and spatial scales). Authentication, authorisation and audit systems are currently not well scalable and may present bottlenecks for distributed collaboration particularly where outcomes may be commercialised. Challenges remain in providing lightweight standards to facilitate the penetration of robust, scalable grid-type computing into diverse user communities to meet the evolving demands of systems biology.

Animals↗

DNA computing using single-molecule hybridization detection.

DNA computing aims at using nucleic acids for computing. Since micromolar DNA solutions can act as billions of parallel nanoprocessors, DNA computers can in theory solve optimization problems that require vast search spaces. However, the actual parallelism currently being achieved is at least a hundred million-fold lower than the number of DNA molecules used. This is due to the quantity of DNA molecules of one species that is required to produce a detectable output to the computations. In order to miniaturize the computation and considerably reduce the amount of DNA needed, we have combined DNA computing with single-molecule detection. Reliable hybridization detection was achieved at the level of single DNA molecules with fluorescence cross-correlation spectroscopy. To illustrate the use of this approach, we implemented a DNA-based computation and solved a 4-variable 4-clause instance of the computationally hard Satisfiability (SAT) problem.

Algorithms↗

Evaluation of a computer-based program for teaching cardiac anatomy.

RATIONALE AND OBJECTIVES: The authors determined to what extent a computer-based program could enhance or substitute for cadaver dissection in teaching cardiac anatomy to first-year medical students. METHODS: First-year medical students (n = 175) were randomized into four groups. Group 1 (control) received no instruction, group 2 participated in cardiac dissection, group 3 viewed the computer application, and group 4 performed cardiac dissection and then viewed the computer application. Each group was tested with 10 ultrafast computed tomographic static images and 8 cardiac cadaver specimens. RESULTS: The computer program plus dissection was superior to either the computer program alone or dissection alone; however, the results varied according to the subtest used to assess the outcomes. CONCLUSIONS: Cardiac computer instruction after dissection resulted in dramatically improved image testing performance. However, computer instruction should not replace dissection for teaching cardiac anatomy.

Anatomy↗

Measuring nurses' computer competency: an analysis of published instruments.

The rapid expansion of computer-driven technologies into multiple aspects of modern healthcare suggests that many of the important competencies of the 21st century nurse will encompass mastery of computer technology. This is a comprehensive review of the published measures of computer competence during the past 12 years. Essential knowledge, attitudes, and skills were identified and classified. Multiple competency assessment instruments of varying quality were examined. Little agreement was found regarding specific computer-focused competencies necessary for nurses. Taken as a whole, however, there is consensus that the computer-competent nurse possesses a general knowledge and understanding of computer technology, coupled with a positive attitude toward computers and software. In addition, such a nurse is skillful in computer hardware and software use and able to grasp how such technology benefits nursing and the overall healthcare environment.

Attitude to Computers↗

Computers in patient education.

Nurses in practice have an increasing need to become aware of the computer-based resources available and the evidence regarding their use in the process of patient education. This synthesis of the literature examines research related to computer-based patient education. A particular focus is placed on the nurse clinician's perspective and the role of the nurse as a patient educator in the digital age. Two primary healthcare database resources, MEDLINE and CINAHL, were selected for review of the current literature. A listing of articles related to the use of computer technology in patient education was obtained from both of these databases. The search strategy included exploding the subject heading terms "computer" and "patient education," and included articles from 1971 to 2001. Computer-based patient education is an effective strategy for improving healthcare knowledge and clinical outcomes. Computer-based learning can be tailored to the individual's age and specific learning needs. Furthermore, although access to computer-based resources continues to be a barrier for some, socioeconomic disparities have no reported impact on patients' abilities to use computer-based technologies effectively.

Attitude to Computers↗

The correlation of preoperative three-dimensional computed tomography reconstructions with operative findings in congenital scoliosis.

STUDY DESIGN: A retrospective radiographic and chart review of patients who underwent computed tomography with three-dimensional reconstructions before single stage anterior and posterior hemivertebra excision. OBJECTIVE: To assess the efficacy of three-dimensional computed tomography reconstructions in accurately identifying congenital vertebral anomalies. SUMMARY OF BACKGROUND DATA: Computed tomography allows better imaging of bony architecture than plain films alone. Three-dimensional computed tomography reconstructions facilitate visualization of complex anatomic structures. The correlation of three-dimensional computed tomography reconstructions with the intraoperative anatomy of hemivertebra has not been reported. METHODS: Fifteen patients were retrospectively investigated. The plain films, three-dimensional computed tomography reconstruction scans, and operative reports were each blindly reviewed to determine the anatomy. We then correlated the findings of each imaging study with the intraoperative anatomy. RESULTS: Compared with intraoperative findings in 15 cases, three-dimensional reconstructions of computed tomography scans accurately predicted anterior and posterior vertebral anomalies in all cases. Plain radiographs accurately predicted anterior anatomy; however, 11 out of 12 posterior anomalies were not seen on plain film evaluation. CONCLUSIONS: Three-dimensional reconstructions of computed tomography scans are more helpful than plain films in visualizing posterior vertebral anomalies associated with hemivertebra. Unexpected anomalies may be encountered posteriorly when plain films alone are used in surgical planning.

Child↗