[Use of methods of computerized differential diagnosis for the systems analysis of the electrical activity of the brain of schizophrenic patients].
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Adolescent↗
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Results for “Systems Analysis”
Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.
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Systems analysis and guidelines for behavioral scientists in family medicine.
A recurrent theme among behavioral scientists is the difficulty of being a nonphysician in a medical setting. Differences in training and in work roles can create misunderstanding between physicians and behavioral scientists; and being a minority in terms of profession can be isolating and demoralizing. To date, analyses have focused on the individual differences between the two groups and not on the context--the larger system--in which the two work. This article examines these systemic problems, particularly problems specific to family medicine. Coping methods which can be used by behavioral scientists are proposed to help them reduce the work stress they experience.
Behavioral Sciences↗
A grid-based image archival and analysis system.
Here the authors present a Grid-aware middleware system, called GridPACS, that enables management and analysis of images in a massive scale, leveraging distributed software components coupled with interconnected computation and storage platforms. The need for this infrastructure is driven by the increasing biomedical role played by complex datasets obtained through a variety of imaging modalities. The GridPACS architecture is designed to support a wide range of biomedical applications encountered in basic and clinical research, which make use of large collections of images. Imaging data yield a wealth of metabolic and anatomic information from macroscopic (e.g., radiology) to microscopic (e.g., digitized slides) scale. Whereas this information can significantly improve understanding of disease pathophysiology as well as the noninvasive diagnosis of disease in patients, the need to process, analyze, and store large amounts of image data presents a great challenge.
Computer Communication Networks↗
System analysis of heart rate control in man.
The dynamic property of the heart rate response to exercise was determined and expressed in the frequency domain to establish a method of examining cardiovascular control function. The response of heart rate to a stimulus was measured at 5-s intervals in nine healthy young volunteers. The stimulus consisted of several runs of two-step exercise practiced in semirandom sequence for 19 min. The weight function of the system was estimated from autocorrelation function of the input signal and cross-correlation function between the input and output signals. The weight function was transformed into a transfer function and its Bode plot diagram was drawn. From the diagram, four dynamic parameters were determined. These parameters are as follows: K is a constant showing the theoretical steady-state increment of heart rate, and T1, T2, T3 are time constants. The values obtained in the present experiment with the healthy young males were: K 46.0 +/- 14.6 beats, T1, 2.12 +/- 0.44, T2, 1.12 +/- 0.16, and T3 0.70 +/- 0.07 min.
Adult↗
Power-law modeling based on least-squares criteria: consequences for system analysis and simulation.
The power-law formalism was initially derived as a Taylor series approximation in logarithmic space for kinetic rate-laws. The resulting models, either as generalized mass action (GMA) or as S-systems models, allow to characterize the target system and to simulate its dynamical behavior in response to external perturbations and parameter changes. This approach has been succesfully used as a modeling tool in many applications from cell metabolism to population dynamics. Without leaving the general formalism, we recently proposed to derive the power-law representation in an alternative way that uses least-squares (LS) minimization instead of the traditional derivation based on Taylor series [B. Hernández-Bermejo, V. Fairén, A. Sorribas, Math. Biosci. 161 (1999) 83-94]. It was shown that the resulting LS power-law mimics the target rate-law in a wider range of concentration values than the classical power-law, and that the prediction of the steady-state using the LS power-law is closer to the actual steady-state of the target system. However, many implications of this alternative approach remained to be established. We explore some of them in the present work. Firstly, we extend the definition of the LS power-law within a given operating interval in such a way that no preferred operating point is selected. Besides providing an alternative to the classical Taylor power-law, that can be considered a particular case when the operating interval is reduced to a single point, the LS power-law so defined is consistent with the results that can be obtained by fitting experimental data points. Secondly, we show that the LS approach leads to a system description, either as an S-system or a GMA model, in which the systemic properties (such as the steady-state prediction or the log-gains) appear averaged over the corresponding interval when compared with the properties that can be computed from Taylor-derived models in different operating points within the considered operating range. Finally, we also show that the LS description leads to a global, accurate description of the system when it is submitted to external forcing.
Biometry↗
System analysis for optimal control of a wastewater treatment benchmark.
The paper presents an analysis and optimisation of a wastewater treatment benchmark. The benchmark is a simulation environment defining a plant layout, simulation model, influent data, test procedures and evaluating criteria that should be used for comparing different control strategies. In this paper an analysis of the benchmark which addresses the influences of potential manipulated variables on control performance under different operating conditions is presented. In the study optimisation is used to define the optimal values of the manipulated variables under constant as well as dynamic influent conditions. The results indicate that such an analysis and optimisation give important information about the manipulated variables under varying influent conditions and consequently about possible control strategies.
Computer Simulation↗
Image analysis systems for the detection of disseminated breast cancer cells on bone-marrow cytospins.
We assessed the accuracy of automated cell imaging systems when compared to manual evaluation of cytospin slides in determining the presence of cytokeratin-positive, disseminated breast cancer cells in bone marrow aspirates. A total of 298 cytospin slides of bone marrow aspirates were first evaluated by individual screening by one expert immunocytologist. Subsequently, all 298 slides were evaluated by the Automated Cell Imaging System (ACIS) by ChromaVisiontrade mark. Two separate analysis cycles were performed using ACIS. The results of the two ACIS analysis cycles were almost identical: in 293 out of 298 samples (98.3%), identical numbers of disseminated breast cancer cells were detected. In the remaining five samples (1.7%), the result of the two ACIS analysis cycles differed by only one tumor cell. By using the manual technique, 120 cytospin samples were found to be positive. ACIS was able to detect additional tumor cells in 64 cases. Not once did ACIS miss tumor cells when compared to the manual technique. Using ACIS, we were able to determine the bone marrow status of patients with nonmetastatic breast cancer faster, with greater accuracy, and with greater reproducibility than with the manual technique.
Biopsy, Needle↗
D- and L-lactate determination in dairy products: presentation of a fast automated analysis system.
A flow-injection system is presented, which is versatile, automated and has an integrated enzyme system. Its efficiency at determining D- and L-lactate separately in dairy products is compared with the officially used reference method (DIN 10335). By means of a mathematical elimination of matrix effects, the pretreatment steps can be clearly reduced. As a result of the immobilization of the enzymes, an appropriate automation software and an adaptation of the system developed to the given medium, the analysis could be performed within 5 min and was distinctly cheaper than alternative methods. The values determined in 15 different dairy products deviated from those of the reference method by 3% at a maximum.
Animals↗
A systems analysis approach to medical error.
Evidence from various sources indicates that a substantial number of hospitalized patients suffer treatment-caused injuries. Most of these injuries result from errors. Yet physicians and other health professionals have been reluctant to admit and address the problem of errors, both because of feelings of guilt and from the desire to avoid punishment or disapproval by colleagues. Research in cognitive psychology and human factors has shown that most errors result from defects in the systems in which we work. These are failures in the design of processes, tasks, training, and conditions of work that make errors more likely. Meaningful reduction of errors requires correction of these systems failures. Barriers to reduction of errors include the complexity of health care systems, difficulties in information access, tolerance of stylistic practices, and fear of punishment that inhibits reporting. Most institutions also lack effective methods for detecting and quantifying errors. Significant improvements in error reduction will require major commitments by organizational leadership and the recognition that errors are evidence of deficiencies in systems, not deficiencies in people.
Data Collection↗
Electrokinetically controlled microfluidic analysis systems.
Electrokinetic forces are emerging as a powerful means to drive microfluidic systems with flow channel cross-sectional dimensions in the tens of micrometers and flow rates in the nanoliter per second range. These systems provide many advantages such as improved analysis speed, improved reproducibility, greatly reduced reagent consumption, and the ability to perform multiple operations in an integrated fashion. Planar microfabrication methods are used to make these analysis chips in materials such as glass or polymers. Many applications of this technology have been demonstrated, such as DNA separations, enzyme assays, immunoassays, and PCR amplification integrated with microfluidic assays. Further development of this technology is expected to yield higher levels of functionality of sample throughput on a single microfluidic analysis chip.
Chemistry Techniques, Analytical↗
Subdividing atypical glandular cells of undetermined significance according to the Australian modified Bethesda, system: analysis of outcomes.
BACKGROUND: The Australian modification of the Bethesda system (TBS) for reporting endocervical cellular abnormalities differs from TBS in having a "high grade" category for prediction of adenocarcinoma in situ (AIS), an "inconclusive" category requiring that AIS be excluded (AISEX), and a "low grade" category (Enatyp) for when only minor changes are seen in endocervical cells. METHODS: From subsequent follow-up, the authors evaluated the proportion of histologically confirmed high grade lesions (squamous, glandular, or endometrial) in each cytologic reporting category, for cases in which no concurrent squamous abnormality was also predicted. RESULTS: From information was available for 95.9% of 172 AIS predictions, 81.5% of 119 AISEX predictions, and 89.0% of 237 reports of Enatyp. The histologic positive predictive values for high grade lesions were 95.7% for AIS, 71.1% for AISEX, and 7.1% for Enatyp. In the first 2 categories, a minority of lesions proved to be purely squamous (3.8% for AIS and 33.3% for AISEX), whereas in the Enatyp category 87.0% were squamous only. CONCLUSIONS: Compared with TBS, the Australian terminology for reporting of endocervical abnormalities better reflects the risk of underlying high grade abnormalities and may result in more appropriate management recommendations. For Enatyp reports, which constitute over 85% of reported endocervical abnormalities, repeat cytology should be considered appropriate management. However, cone biopsy should be the investigative method of choice for women with reports of AIS and AISEX.
Adenocarcinoma↗
Activated sludge image analysis system: monitoring settleability and effluent clarity.
A fully automized image analysis procedure is presented for fast and reliable characterization of the activated sludge composition. In previous research, relations between filament abundance and floc shape on the one hand, and the Sludge Volume Index on the other hand were sought. This work aims at demonstrating the use of the image analysis information as an indication for the amount of suspended solids in the effluent.
Automation↗
Infant crying and stability in the mother-infant relationship: a systems analysis.
Mother-infant interaction was studied using a general systems theory framework. 20 mother-infant pairs were observed in their home for a 7-hour period when the infants were 2, 3, 4, and 5 weeks of age. A measurement procedure was devised to assess, for each pair, the consistency over weeks in their allocation of time to 4 interactional contexts that make up the day: feeding, changing or bathing, social attention, and baby alone. The measure was called an Interactional Stability Score. Construct validity for this measure was investigated based on our hypothesis that high interactional stability would be strongly linked to low levels of crying during social attention. This hypothesis was confirmed. The results are interpreted within a general systems theory perspective--namely, that this measure of interactional stability is an empirical indicator of the degree of equilibrium within the relationship, at the level of patterning of interactional contexts. High stability scores represent consistency in allocation of time to the 4 contexts over weeks and not a rigidity in sequencing of these contexts, and thus appeared to reflect a dynamic process of mutual constraints on the behaviors of both partners.
Child Development↗
[Separation and fluorimetric determination of adrenaline and noradrenaline. Combination of a high-pressure liquid chromatograph with an automatic analysis system].
The possibilities for a high-pressure liquid chromatographic analysis combined with automatic fluorimetric detection of the catecholamines adrenaline and noradrenaline are described. The optimal conditions are given for a fast separation by ion exchange and reversed-phase chromatography, and for the sensitive fluorimetric determination of adrenaline by the trihydroxyindole technique when a high excess of noradrenaline is present.
Autoanalysis↗
A systems analysis approach to postoperative wound infections. Phase II. A microbiological assessment for the exogenous bacterial controls in the operating room.
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Air Conditioning↗
[The systems analysis of the effect of piracetam, glycine and N-acetylglycinamide on long-term learning].
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Animals↗
Systems analysis of arterial pressure regulation and hypertension.
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Aldosterone↗
EMMA--an eye movement measurement and analysis system.
A system has been developed for stimulation, recording and analysis of a wide range of eye movements. Eye movements are stimulated with an LED bar or a video projector under the control of a PC. The eye movements are measured using a scleral reflection technique (IRIS instrument), and sampled and stored on a PC. A range of tests have been developed to measure saccadic and smooth pursuit eye movements. A variety of tools have been developed to assist in the analysis of the data. Several research studies have ably demonstrated the utility and versatility of the system.
Equipment Design↗