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Results for “Numerical Analysis, Computer-Assisted”

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At least 55 records · Page 3Linked to original sources
PubMed1992

PADS (Patient Archiving and Documentation System): a computerized patient record with educational aspects.

Rapid acquisition and analysis of information in an Intensive Care Unit (ICU) setting is essential, even more so the documentation of the decision making process which has vital consequences for the lives of ICU patients. We describe an Ethernet based local area network (LAN) with clinical workstations (Macintosh fx, ci). Our Patient Archiving and Documentation System (PADS) represents a computerized patient record presently used in a university hospitals' ICU. Taking full advantage of the Macintosh based graphical user interface (GUI) our system enables nurses and doctors to perform the following tasks: admission, medical history taking, physical examination, generation of problem lists and follow up notes, access to laboratory data and reports, semiautomatic generation of a discharge summary including full word processor capabilities. Furthermore, the system offers rapid, consistent and complete automatic encoding of diagnoses following the International Classification of Disease (ICD; WHO, [1]). For educational purposes the user can also view disease entities or complications related to the diagnoses she/he encoded. The system has links to other educational programs such as cardiac auscultation. A MEDLINE literature search through a CD-ROM based system can be performed without exiting the system; also, CD-ROM based medical textbooks can be accessed as well. Commercially available Macintosh programs can be integrated in the system without existing the main program thus enabling users to customize their working environment. Additional options include automatic background monitoring of users learning behavior, analyses and graphical display of numerous epidemiological and health care related problems. Furthermore, we are in the process of integrating sound and digital video in our system. This system represents one in a line of modular departmental models which will eventually be integrated to form a decentralized Hospital Information System (HIS).

Computer User Training↗
PubMed1992

A neuromuscular monitoring system based on a personal computer.

We have developed a computerized neuromuscular monitoring system (NMMS) using commercially available subsystems, i.e., computer equipment, clinical nerve stimulator, force transducer, and strip-chart recorder. This NMMS was developed for acquisition and analysis of data for research and teaching purposes. Computer analysis of the muscle response to stimulation allows graphic and numeric presentation of the twitch response and calculated ratios. Since the system can store and recall data, research data can be accessed for analysis and graphic presentation. An IBM PC/AT computer is used as the central controller and data processor. The computer controls timing of the nerve stimulator output, initiates data acquisition, and adjusts the paper speed of the strip chart recorder. The data processing functions include establishing control response values (when no neuromuscular blockade is present), displaying force versus time and calculated data graphically and numerically, and storing these data for further analysis. The general purpose nature of the computer and strip chart recording equipment allow modification of the system primarily by changes in software. For example, new patterns of nerve stimulation, such as the posttetanic count, can be programmed into the computer system along with appropriate data display and analysis routines. The NMMS has functioned well in the operating room environment. We have had no episodes of electrocautery interference with the computer functions. The automated features have enhanced the utility of the NMMS.(ABSTRACT TRUNCATED AT 250 WORDS)

Computer Systems↗
PubMed1992

[Evaluating the independence of paraplegic patients at the end of the first rehabilitation--a multicenter project of computer-assisted quality control in rehabilitation].

Rehabilitation of patients who became handicapped due to illness or trauma is a difficult process, involving many therapeutic sections. The necessity to document the results of different rehabilitation programs led to the development of numerous scoring systems in the USA within the last 25 years, considering mainly functional results. The present functional assessment score (DMGP-Selbständigkeitserfassung für Tetraplegiker) for the documentation of self-sufficiency in tetraplegic patients after primary rehabilitation has been designed to record the quality of rehabilitation programs and has been exclusively designed for patients with quadriplegia, it there fore has the advantage of a better and more precise documentation over other general functional scoring systems, especially for the interests of different sections (occupational therapy, physiotherapy) being involved in this special rehabilitation program. The aim of the documentation is to record the degree of independence of tetraplegic patients after primary rehabilitation, considering the individual requirements of aids and the assumption of circumstances suitable for wheel-chairs. Since all data are collected on a computer-readable form each participating clinic has the opportunity for an individual analysis of the own results, as well as the opportunity of comparing it with the collective results.

Activities of Daily Living↗
PubMed1992

Postterm pregnancy: computer analysis of the antepartum fetal heart rate patterns.

The purpose of this study was to establish reference ranges for numerical fetal heart rate (FHR) data in postterm pregnancy and to compare them with the patterns of fetuses under undisturbed condition at term. FHR was analysed on-line by Sonicaid Computer System 8000. A statistically significant decrease in the number of accelerations and decrease of variation in postterm pregnancy was observed. The duration of high variation (high episodes) in the 42nd week of gestation was statistically lower than in the pregnancy at term. These observations should be taken into account by clinicians in the interpretation of FHR records in postterm pregnancy.

Cardiotocography↗
PubMed1992

Quantitation of rodent catalepsy by a computer-imaging technique.

Catalepsy is usually defined as a behavioral state in which an animal maintains an unnatural posture for an extended period of time. While numerous laboratory models have been developed for assessing catalepsy, a common problem encountered with most procedures is the difficulty in quantitating immobility. Measurement of catalepsy is still frequently subjective in nature. To eliminate this subjectivity, a computer-based technique was developed for quantitating catalepsy in mice and rats as measured on the elevated ring. The system consisted of a video camera that was focused on either three mice or two rats. Their behavior was recorded during a 5-min session on videotape that was subsequently transmitted to a Macintosh II microcomputer via a Scion Image-Capture 2 board. A modification of the NIH Image 1.17 public domain program allowed the image of the rat to be transformed to a purely black or white image by assigning pixel values of either 0 or 256. The subsequent captured image was preprocessed in an identical manner and each pixel was subtracted from its corresponding pixel in the previous frame. Thus, changes in animal posture between the two frames can be quantitated. One subtraction cycle (acquisition, bilevel processing, and subtraction) was repeated at an average rate of approximately one per second. To quantitate immobility by image analysis, each frame was subtracted from the previous frame during a 5-min session. The resulting data were sorted according to the magnitude of movement (number of changed pixels) and plotted vs. time.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMedDate not supplied

Combining evidence from multiple imaging modalities: a feature-analysis method.

This study was designed to develop methods to improve radiologists' ability to detect and diagnose breast cancer. We evaluated the ability of a feature-analysis method to help radiologists merge judgements constructively from two rather disparate breast imaging tests. To accomplish these goals, we developed a list of perceptual features and quantitated the importance of each in the diagnosis of patients having both diaphanography (Test 1) and mammography (Test 2). Then, two decision aids were developed: One was a checklist of the critical diagnostic visual features from both tests that also assisted readers in rating these features numerically. The second was a computer-based classifier that assisted readers in merging the assessments of the two tests into one overall diagnostic probability. The value of these aids was assessed by comparing radiologists' accuracy in reading a set of proven cases in their standard fashion with their accuracy when reading in an enhanced mode, utilizing the checklist and computer classifier. When Test 1 was read adjunctively with Test 2, use of the decision aids led to a significant improvement in accuracy (p = .013) over the unenhanced, combined readings. For Test 1 alone, the aids led to a significant improvement over its low level of unenhanced reading (p = .046). For Test 2 alone, the enhancements provided little gain in accuracy over an already high level of performance on the full case set (p = .081), although significant gains were realized on the most difficult ones. We conclude that methods to aid standardization and merging of feature-based judgements can improve radiologists performance on complex diagnostic tasks.

Breast Neoplasms↗
PubMed1992

[New aspects in the evaluation of Doppler blood flow curves: three- dimensional image and analysis of Doppler shift frequencies within the heart cycle].

Since the introduction of Doppler ultrasound to the area of medical diagnostics, there have been numerous improvements and important technical refinements. In obstetrics, Doppler examination allows a more accurate and encompassing evaluation of the foetal condition than was previously possible. Combined with today's sophisticated computer technology, it has a great potential in research and to expand our knowledge about the physiology and pathophysiology of foetal and maternal haemodynamics. This paper describes a new way of integrating another factor into the evaluation of Doppler blood flow waveforms, namely, the intensities of various frequencies. One result should be more detailed information about the given haemodynamic situation; another, a valuable tool for the quality control of Doppler blood flow measurements. Although our work was on applications in the field of obstetrics, the method we have developed can be used in all medical areas.

Blood Flow Velocity↗
PubMed1977

Automated, rapid identification of bacteria by pattern analysis of growth inhibition profiles obtained with Autobac 1.

A scheme for identifying bacteria has been devised which utilizes the inhibition patterns obtained by Autobac 1 with routine and unusual antimicrobial agents and with other differentially inhibitory chemical compounds. Over 600 compounds were initially identified from the literature, and over 125 of these were selected for further testing on the basis of antibacterial activity most conducive to the instrument-generated differential scheme. Numerical growth index information derived by light scatter comparisons from the instrument were analyzed by computer, utilizing the quadratic discriminant function statistical technique. In comparison with conventional methods, accuracy for the 10 bacterial genera studied was 95% or greater. Results indicate a potential for both bacterial identification and antimicrobial agent susceptibility testing in the clinical laboratory within 3 to 5 h when using this automated approach.

Acinetobacter↗
PubMed1977

Results of computer-aided diagnosis of peripheral bronchial carcinoma.

Radiographic images can be converted into numerical sequences that can be evalueate by computer to determine the significance of certain radiographic findings in peripheral pulmonary nodules. Of three methods (discriminant analysis. Bayes' theoroem, and the Calm system), discriminant analysis has proven the best with an accuracy rate of 85%. By taking into account serial radiographs and statements on the possible growth of the neoplasm, the accuracy of the method can be increased to 90%. A simplified, inexpensive and effective method for application of this diagnostic tool is described.

Adult↗
PubMed1992

The measurement of blood flow waveforms from X-ray angiography. Part 1: Principles of the method and preliminary validation.

The principles and implementation of a method for measurement of blood flow waveforms from X-ray angiography are described. Contrast medium mass values are obtained at multitudinous positions along individual vessels and from numerous images in a time sequence. These values are represented as a matrix of grey levels in a parametric image. This image is normalized to represent contrast medium concentration, and the movement over time of isoconcentration portions of the contrast bolus is recovered to determine blood flow. Preliminary validation has been undertaken using parametric images generated in two ways: synthesis from a computer model of vascular pulsatile flow and analysis of cine-angiograms of physical models (plastic and perspex tubes) carrying known pulsatile flows. Two distinct methods for interrogation of parametric images by digital image processing were employed; both provided accurate flow measurements.

Blood Flow Velocity↗
PubMed1975

Computer analysis of defined populations of lymphocytes irradiated in vitro. II. Analysis of thymus-dependent versus bone marrow-dependent cells.

Three uniform populations of T and B cells exposed to varying amounts of x-irradiation are examined utilizing computer-assisted morphometric analysis. These populations are: thoracic duct lymphocytes (TDL) from congenitally athymic (nude) mice (B cells); TDL from CBA mice treated with anti-Ig plus complement (T cells); and computer-selected untreated T cells from CBA TDL. Irradiated B cells show a more even dispersion of the nuclear chromatin and a dose-dependent increase in relative nuclear area beginning with the lowest dose evaluated (50 rads); no significan change in total optical density (OD) is demonstrable over the dose range evaluated (0 to 2000 rads). Anti-Ig-treated irradiated T cells demonstrate an initial shift toward lower OD values as a function of dose followed by a marked rise of OD values at 2000 rads, where numerous densely staining Feulgen-positive aggregates are identified. The relative nuclear area of this cell population also shows a biphasic response to radiation injury with an initial increase at the lower dose levels followed by a progressive decline to approximate control levels at 2000 rads. This effect is mirrored by the alteration in total OD which, after a decrease at low dose levels, approximates control values at 2000 rads. The computer-selected T cells show little change in OD values at the low-dose levels but show a marked increase in the more densely staining Feulgen-positive material following 2000 rads. This population reveals no apparent change in either relative nuclear area or total OD as a function of dose. Thus, untreated computer-selected T cells exhibit remarkably little evidence, morphologically, of radiation injury of doses associated with pronounced alterations on the part of B cells. In addition, treatment of a mixed cell population (CBA TDL) with anti-Ig plus complement to remove the B cells appears to alter the response of the residual T cells to radiation injury. These results, in conjunction with recent evidence to support the concept that T cells possess surface Ig, suggest that an Ig-anti-Ig interaction may alter the radiosensitivity of T cells.

Animals↗
PubMed1992

Computer-aided classification of malignancy in astrocytomas. I. The value of nuclear parameters obtained by automated black and white image analysis.

Ninety-three selected cases of astrocytomas including glioblastomas (astrocytomas grades 1-4) were evaluated by means of Feulgen-stained microscopic slides for nuclear parameters obtained by automated black and white image analysis (ABWIA). The goal was to determine to what extent nuclear features evaluated by ABWIA were applicable as classifiers for the computer-aided numerical classification of malignancy in astrocytomas. Before the automated evaluation, all tumours had been subjectively graded according to the Mayo Clinic grading rules as delineated by Ringertz. Twenty-three nuclear parameters were evaluated and tested for their classification impact. With a model of five parameters (number of nuclei per area, mean of the convex form factor, extinction sum, extinction variation, and full-width-half-maximum of the extinction distribution) the highest reclassification rate of 75% correctly reclassified cases was obtained. Although this is a good result for a classification using only nuclear parameters, it is too poor for practical application. Thus, nuclear parameters evaluated by ABWIA alone are insufficient for numerical classification models assessing the malignant expression of astrocytomas.

Astrocytoma↗
PubMed1992

Computer-aided classification of malignancy in astrocytomas. II. The value of categorically evaluated histologic and non-histologic features for a numerical classifier.

The present study was carried out in order to obtain a numerical classifier for the assessment of the malignancy in astrocytomas including glioblastomas ('astrocytomas grade 4'). The attempt resulted in 'TESTAST 268', a classifier based on a reference sample of 268 tumours, 67 in each of four malignancy classes. TESTAST 268 aids the identification of astrocytomas with one of four malignancy classes by means of eight classification variables, five histologic and three non-histologic. Identification is achieved with the aid of linear discriminant functions, both according to Bayes' decision rule (BAYTEST) and by canonical discriminant analysis (CANTEST) using the squared Mahalanobis distance. The discriminant functions with the calibration of the reference sample of the 268 tumours may be implemented on personal and even small pocket computers for practical application.

Astrocytoma↗
PubMed1992

[Neurophysiologic monitoring in neurosurgical vascular operations: specific technical requirements and their conversion].

Several authors have presented evidence for a strict relation between regional cerebral blood flow and EEG. Therefore the EEG can serve as an adequate physiological parameter when monitoring cerebral function in the operating room. However, to exploit the inherent information as far as possible, both multichannel EEG and somatosensory evoked potentials should be recorded simultaneously. In the present article we describe a monitoring system which is capable to handle this task under the conditions of an operating room. In the first step some numerically simple algorithms are applied to detect gross artifacts. In the subsequent processing stage an analysis procedure is performed which is robust with respect to the remaining more subtile artifacts. In addition the raw signals are continually displayed on a monitor to allow for a visual evaluation of the EEG. The results of a trend analysis procedure are presented on the same graphical display by means of a compact topographical scheme. The system has been running under routine conditions for approximately two years now.

Artifacts↗
PubMed1978

Enlarged acid-base and blood gas calculations by electronical data computing in the blood gas laboratory.

A rapid anaysis of parameters of the acid-base equilibrium and blood gases during open heart surgery and emergency therapy is absolutely necessary. Computing of the several parameters of the acid-base status by slide rules or nomograms is time consuming and can be shortened by computer applications. The central blood gas laboratory consists of a blood gas analyzer for PO2, PCO2 and pH, an electronic desktop calculator, a four color X-Y-plotter and two data lines to the cardiac surgery unit and to the intensive care unit. The time needed for computing and feedback of the parameters could be decreased to one quarter. In addition to numerical data printout, a graphical representation of the several parameters is possible on a X-Y-plotter and includes the Rahn-Fenn-O2-CO2-Diagram with venous admixture, ventilation perfusion ratio, alveolar dead space ventilation and the standard and actual oxygen dissociation curve as well as the pH/HCO3- Acid-Base nomogram. Furthermore, a computer diagnosis of the actual disturbances can be plotted.

Acid-Base Equilibrium↗
PubMed1977

[Multivariant discriminance analytical computation methods for the evaluation of clinico-chemical parameters in liver and biliary tract diseases].

Multivariate variance and discriminance-analytic investigations on the value of evidence of clinico-chemical tests in the diagnostics of diseases of the liver and the biliary tract gave the following results: 1. By means of clinico-chemical methods and discriminance-analytic functions we succeed in 50% of the cases in formulating a correct diagnosis, in more than 75% of the cases a correct probability diagnosis (3 first places in the rank of diagnoses). Sensitivity and specificity of discrimination were established for 15 classes of diagnoses. 2. Due to the intercorrelations of test results biochemical maximum programmes contain numerous redundant parameters measured on diagnostic information values. With the help of a test for indispensability (redundance test) among 20 parameters owy 5-6 were characterized as indispensable. An optimal combination of parameters should not transgress an extent of 14 tests. 3. Results of reclassifications with discriminance analytic functions confirmed that the discriminance analysis is an extraordinarily suitable method for the computer-supported finding of a decision, on which basis aimed additional investigations might be performed.

Analysis of Variance↗
PubMed1977

[Nystagmus analysis by computer (author's transl)].

Automatic quantitative nystagmus analysis by means of a digital computer primarily gives a lot of data. Analysis then means reducing this amount of numerical data to a few relevant results. Because the diagnostic importance is not known yet for all available nystagmus parameters, this implies the risk of losing essential informations. Therefore, limitations of the number of parameters as well as of the duration of the investigated intervals by the method of analysis have to be avoided. This then allows studying the diagnostic value of new parameters (e.g. of the fast components) or the time course of reaction intensity. From this point of view a method of quantitative nystagmus analysis is described.

Computers↗
PubMed1979

[Objectivation of tremor and motion disorders via computerisation (author's transl)].

The quantitative analysis of motion disorders of the upper extremities can be performed by means of a joystick connected with a minicomputer. Therefore a random squarewave curve is drawn on a computer display and the patient must follow it with the joystick. The deviation of the two curves are recorded, analysed and documented numerically and graphically.

Diagnosis, Computer-Assisted↗