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At least 415 records · Page 23Linked to original sources
PubMed1991

The use of modified constellation graph method for computer-aided classification of congenital heart diseases.

This paper describes a new method of data reduction and classification in a multidimensional symptom space for diagnostic aid of congenital heart diseases. The algorithm developed here is to reduce interactively a multidimensional symptom space to sectorial regions representing each disease in a semicircle using the modified constellation graph method. This method enables us to classify patients using the angle in the semicircle as a single classifying parameter with an accuracy of about 90%, that is, with little overlapping between disease sectors. Comparing this method with conventional factor analysis, we have found the former far more effective than the latter for disease region separation.

Algorithms↗
PubMed1984

Computer-aided tinnitus characterization.

A purpose-built tinnitus synthesizer interfaced to a computer has been designed which can be used to characterize most types of subjective tinnitus. A patient is able to match his own tinnitus by making responses to simple questions using push buttons on a hand-held box. The system can be used to determine the characteristics of tinnitus consisting of tones, random noise or combinations of these sounds; any sound can also be pulsed synchronously with a patient's pulse beat in order to match pulsatile tinnitus. It is then possible to use the frequency and loudness characteristics of tinnitus in order to determine the suitability of masking therapy for a patient.

Audiometry↗
PubMed1987

Computer-aided volume measurement of choroidal melanomas.

Using a combination of conventional B-scan ultrasonography, standard video techniques, computer image digitization and area analysis, it is possible to measure the volume of choroidal melanomas by area calculation of successive ultrasound image slices, allowing the monitoring of such tumors. The design of a combined water-bath and linear tracking B-scan transducer is presented, together with a description of the instrumentation and computer software required. The results of volume measurements performed upon eye models demonstrated that melanomas of volume greater than 100 mm3 could be measured with an average error of 6%. The problems associated with linear calibration of the system from scan-head to analysed image, resolution of the digitised image, reproducibility of the measurements, sources of error and assumptions made in formulating the measurement procedure are discussed.

Adult↗
PubMed1990

Development of computer-aided motion analyzing (CAMA) system for radiopaque implanted tilting disk heart valves.

The newly developed semiautomatic data acquisition and processing system allows progress in quantitative evaluation of functions of implanted tilting disk valves. In the new system, data acquisition could be carried out semiautomatically by utilizing image processing methods, and the data analysis time was shortened. The system consists of a computer-controlled cinefilm loading device, a CCD camera, a frame memory, a superimposer, and CRT displays. Since series of the open- and shut-mode frames are commonly observed by turns in normal subjects, data acquisition was carried out manually at the first frame of each mode and semiautomatically from the second frame to the last. By processing the image data with the binarization method, the valve contours were detected, and an open angle and other motion properties can be obtained. Analyzing 90 frames of the cinefilm, this system analyzes data in a time period 20 min shorter than the manual procedure. With the implanted Medtronic Hall valve, a 60 to 65 degrees open angle was calculated.

Cineradiography↗
PubMedDate not supplied

Bayesian statistics: a guided tour.

An overview of Bayesian statistical decision theory is presented in the tutorial spirit. A section on fundamental principles is followed by selected applications of the Bayesian approach to parameter estimation, pattern recognition, image processing, computer-aided medical diagnosis, optimal diagnostic test selection, and radiotherapy treatment planning.

Decision Making↗
PubMed1992

Patch test results of the Dermatology Clinic Zurich in 1989: personal computer-aided statistical evaluation.

The patch test results of 921 consecutively tested patients were registered on an IBM personal computer. A computer program based on the dBase III plus database software, especially designed for this purpose, was used. The statistical evaluation was performed with dBase III plus. 59% of the probands were females and 41% males. The average age was 42.8 years. 26% of the probands were inpatients and 74% outpatients. A majority of the patients presented with eczema of the hands, face or the lower legs. The largest occupational groups were houseworkers and cleaning personnel, office workers and pensioners. To 450 of the 921 patients, at least 4 test series were applied simultaneously. These included European standard, vehicles and emulgators, topical medications, and preservatives and biocides. The other 20 test series available were employed only by 2-81 patients each. The highest sensitization rates were found with: nickel, 18.7%; cobalt, 10.2%; balsam of Peru, 8.8%; framycetin, 8.0%; neomycin, 6.8%; potassium dichromate, 6.1%; p-phenylene diamine, 5.4%; paramix, 4.9%; formaldehyde, 4.8%, and (chlor)methylisothiazolinone, 4.7%. The critical evaluation of the data showed two kinds of problems: first, test-specific aspects led to optimization of the patch test procedures; second, the crucial importance of an adequate statistical analysis for epidemiological investigation was revealed.

Adolescent↗
PubMed1992

A comparison of conventional intra-oral radiography and computer imaging techniques for the detection of proximal surface dental caries.

The detection of proximal surface caries by the visual interpretation of bitewing radiographs is known to be relatively inaccurate. The present study was designed to examine whether computer image processing could improve the diagnostic accuracy. A computer-aided, software-driven, TV-based system was used to digitize conventional radiographs and digitally process the images using histogram equalization and grey-scale inversion to enhance the images. The computer-enhanced images were compared with conventional intra-oral radiographs for the detection of proximal surface caries using receiver operating characteristic analysis. The results indicate that the digital image processing techniques used did not improve the diagnostic accuracy of dental radiographs. No significant difference in diagnostic accuracy could be detected between the non-enhanced digital images and conventional film-based images for the detection of proximal surface caries.

Dental Caries↗
PubMedDate not supplied

A system for computer-aided diagnosis.

MEDICIS is an integrated environment for computer-aided diagnosis. It consists of two subsystems: a module used by the expert to build knowledge bases and a consultation module to exploit those bases. MEDICIS uses a framed representation of knowledge. The inference engine performs logical reasoning without recourse to certainty factors. This phase is followed by a multicriteria analysis.

Diagnosis, Computer-Assisted↗
PubMed1992

[Computer-aided prediction of optimal composition of multicomponent mobile phase in high performance liquid chromatography].

This paper proposed a systematic optimizing method for the composition of multicomponent mobile phase in high performance liquid chromatography. A new chromatographic response function (CRF) has been constructed according to the fundamental retention equation and rule of peak width at half-height, and the optimal composition of multicomponent mobile phase can be automatically predicted by a computer with CRF. This paper improved the known complex method, therefore, the optimal mobile phase composition in the global area may be found by means of this modified complex method. The optimal separation conditions of four vitamins and three nitrophenols were determined by use of the optimizing method reported in this paper. The results predicted by the computer were verified by the experimental data obtained in HPLC using ternary mobile phase.

Chromatography, High Pressure Liquid↗
PubMed1990

Development of a computer-aided reference system for differential diagnostics support.

In a situation of uncertain diagnosis, physicians may spend valuable time consulting relevant literature, often with unsatisfactory results. Therefore, our aim was to develop a computer system which supports differential diagnostics via rapid and comprehensive searches through information in literature. Based on entered signs and symptoms our prototype is able to offer probable diagnoses. Subsequently, further examinations and tests are suggested to confirm or exclude a certain disease. Thus, the final diagnosis is made gradually by differentiation of possible diseases. Our first attempt consisted in representing knowledge in a rule-based PROLOG system. However, because nearly all information for a sign-oriented differential diagnosis can be represented with very few relations only, we turned to a fact-oriented representation of signs and diseases. Access was possible via PROLOG or an imperative programming language. The index-sequential access on a fact-oriented representation of knowledge was suitable to manage a large knowledge base, which is necessary for a thorough differential diagnosis. A pointer structure was recently examined in order to handle different object-to-object relations. Efficient information processing is now possible which provides short response times using even broad knowledge bases.

Diagnosis, Computer-Assisted↗
PubMedDate not supplied

Computer assistance in keratoconus lens design.

In the past, keratoconus patients have been custom fit with multi-curve spherical contact lenses. Recently it has become possible to commercially manufacture aspherical contact lenses of high-Dk material. A computer assisted fitting technique may be used with these new lenses. We report 90 consecutive keratoconus eyes that were fit with aspherical high-Dk contact lenses using a computer-aided fitting system. Mild and severe grades of keratoconus cases were included, with a 6 to 12 month follow-up time. The combination of new lens geometry and lens material produced a reduction in corneal complications. The asphericity of the lens geometry had a slight negative influence on the visual acuity in mild keratoconus cases, but the visual acuity in the severe keratoconus cases was good. The contact lens material proved acceptably durable, despite the high oxygen transmissibility. We found the computer assisted fitting technique very accurate in determining the initial fitting lens and much faster than the former trial-and-error procedure.

Contact Lenses↗
PubMed1987

Computer-aided quality assurance. A critical appraisal.

Computerized information systems hold the promise of overcoming problems in the management of clinical information Many of the claims of the creators and promoters of these systems, however, are not based on sound clinical studies. To determine the ability of computer information systems to improve the quality of medical care, we applied methodologic criteria to published articles in the field. Only 30 (22%) of 135 articles reported preplanned investigations, and only half of these met minimal criteria for scientific investigations. Fourteen studies were well designed and executed. All studies reported improvements in the process of care. However, patient outcomes were not measured, not affected, or only minimally influenced. While computer information systems show increasing potential, more work is required to enhance their effect on the quality of care and thus on patient outcomes.

Evaluation Studies as Topic↗
PubMed1985

Computer-aided nursing diagnosis for community health nurses.

The computer program described in this article was primarily designed to be an aid in the clinical reasoning process. It is intended to simplify the use of nursing diagnoses in the practice of community health nursing. However, in its present form, this program has value not only for the clinician, but also for nursing students being taught structured techniques for assessment. A more comprehensive approach to nursing care and the routine use of nursing diagnoses in providing that care will be encouraged. This article questions the necessity for community health nurses to use computers in their diagnostic role. In answering this question, evidence has been presented that both describes some of the benefits of using computer technology as it relates to nursing diagnoses, and the results of efforts by nurses who have experimented with this technology in trying to improve their practice. One of the advantages of trying to merge a new technology with a relatively new role for community health nurses is the absence of tradition. There is no traditional methodology or approach for integrating the two. And, there is no one to say that it cannot be done. An approach can be tried, changed if it does not work, and tried again. An opportunity to create a new dimension for professional practice is offered. The answer, therefore, to the opening question is, "Yes--community health nurses should be concerned with using computers in their diagnostic role."

Artificial Intelligence↗
PubMedDate not supplied

[Tasks in planning biological experiments].

The paper describes certain cases of using mathematical methods in the planning of biological experiments. The paper presents an algorithm of the distribution of the experimental data based on dynamic programming. The paper discusses an application of computer-aided calculations for the formation of homogeneous groups of experimental and control tests.

Animals↗
PubMedDate not supplied

[Various possibilities for using computer dialogs in biomedical research].

Problems involved in the development of interaction software for biomedical investigations and in the preparation of experimenters for using a computer in the interactive mode are discussed. An interaction program for data analysis is suggested. The program is used to build an interactive modification that makes it possible to carry out a computer-aided verification of the mechanisms of erythropoiesis regulation in space flight. It is shown that a simple interactive terminal facility can be employed in the software of biomedical investigations, taking into account changes in the requirements placed by users and their experience of computer interaction.

Computers↗
PubMedDate not supplied

Potential usefulness of an artificial neural network for assessing ventricular size.

An artificial neural network approach was applied to assess ventricular size from computed tomograms. Three layer, feed-forward neural networks with a back propagation algorithm were designed to distinguish between three degrees of enlargement of the ventricles on the basis of patient's age and six items of computed tomographic information. Data for training and testing the neural network were created with computed tomograms of the brains selected at random from daily examinations. Four radiologists decided by mutual consent subjectively based on their experience whether the ventricles were within normal limits, slightly enlarged, or enlarged for the patient's age. The data for training was obtained from 38 patients. The data for testing was obtained from 47 other patients. The performance of the neural network trained using the data for training was evaluated by the rate of correct answers to the data for testing. The valid solution ratio to response of the test data obtained from the trained neural networks was more than 90% for all conditions in this study. The solutions were completely valid in the neural networks with two or three units at the hidden layer with 2,200 learning iterations, and with two units at the hidden layer with 11,000 learning iterations. The squared error decreased remarkably in the range from 0 to 500 learning iterations, and was close to constant over two thousand learning iterations. The neural network with a hidden layer having two or three units showed high decision performance. The preliminary results strongly suggest that the neural network approach has potential utility in computer-aided estimation of enlargement of the ventricles.

Cerebral Ventricles↗