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PubMed1991

A structured visual language for a knowledge-based front-end to statistical analysis systems in biomedical research.

Within the last few years, several knowledge-based systems for statistical analysis systems have been proposed (see Refs. 1-4 for references). Most of these systems provide so-called 'natural-language' interfaces for acquisition and application of meta-data. Since graphics have been very efficient in displaying results (e.g., as scatter, QQ and residual plots), some attempts have been made (cf. Refs. 5,6) to use graphics also to display knowledge of the statistical strategy. In the present paper I will concentrate on the visualization of knowledge of the experimental design and its impacts on the design of a structured visual syntax language for acquisition and application of this knowledge in the field of biomedical research.

Artificial Intelligence↗
PubMedDate not supplied

A computerized data analysis system for electrogastrogram.

A comprehensive computerized data analysis system for the electrogastrogram is presented in this paper. The electrogastrogram (EGG) is a cutaneous measurement of electrical activity of the stomach by positioning electrodes on the abdominal skin. Since the signal-to-noise ratio of the EGG is very low, visual analysis is impossible. The data analysis system presented in this paper contains a series of PC programs to perform: (a) data acquisition and real-time A/D conversion; (b) digital filter design and digital filtering; (c) adaptive cancellation of respiratory artifact; (d) smoothed power spectral analysis; (e) adaptive running spectral analysis; (f) two- or three-dimensional display of the EGG and analysis results. The basic principles of the system and sample results are presented.

Data Display↗
PubMedDate not supplied

Miniaturized detectors for a chemical analysis system.

Recently, several studies about miniaturized chemical analysis systems fabricated with micromachining methods were reported. These systems have some advantages, such as fast response, small amount of sample, and low consumption of reagents, as compared with the conventional system. With such a small system, design of the detector units is very important to monitor analytical performance. This paper introduces some examples of micromachined detectors for miniaturized chemical analysis systems.

Catecholamines↗
PubMed1998

Some effects of camera placement on the accuracy of the Kinemetrix three-dimensional motion analysis system.

OBJECTIVE: To assess the accuracy of the Kinemetrix motion analysis system to measure horizontal movement by a single reflective marker away from two cameras with differing camera placements. DESIGN: Trial of the effects of nine different camera arrangements on precision of non-human movement. BACKGROUND: In many cases the ability to arrange cameras to allow a separation of 60 degrees is not possible. Little is known about the precision of motion analysis systems for small camera angle separations. METHODS: The accuracy of the Kinemetrix system was assessed with camera horizontal separations of 15 degrees, 30 degrees and 45 degrees, and vertical separations of 0 degrees, 15 degrees and 30 degrees rendering nine different camera placements. The distance between the cameras and the object was always maintained at 4 m. During each test the marker was moved a known horizontal distance along a line bisecting the horizontal angular separation of the two cameras. The mean absolute errors of the Kinemetrix measurement were calculated. RESULTS: At the smallest camera separation tested (15 degrees horizontal, 0 degrees vertical), the Kinemetrix was unable to calculate the three-dimensional co-ordinate of the marker. For all other camera positions tested, the errors in measurements were small (mean absolute errors < 2 mm). CONCLUSIONS: Maintaining camera horizontal and vertical separations above a sum of 30 degrees is sufficient for clinical testing. RELEVANCE: Motion analysis systems are becoming more common for clinical evaluation where only confined testing areas are available. These confined areas often make positioning of cameras at greater than 60 degrees impossible; therefore, there is a need to explore the errors involved in placing two cameras at less than 60 degrees.

Journal Article↗
PubMed2005

A test of the systems analysis underlying the scientific theory of Ayurveda's Tridosha.

A previous paper hypothesized that the tridosha of Ayurveda--vata, pitta, and kapha--constitute regulatory systems respectively controlling input/output, turnover, and storage; functions systems analysis identifies as fundamental to all open systems. This would make them universal properties of all living organisms, as Ayurveda itself maintains. This paper proposes independent scientific evidence for the proposed identification of the doshas and for the systems analysis on which it is based. In particular, it points to coenzyme A, a key component of fatty acid metabolism. Its universal presence in all cells implies that it is an evolutionary invariant ant that the biochemical pathway on which it lies must be exceptionally significant. The systems analysis shows that the pathway connects the cellular functions of energy turnover and energy storage, fundamental to the overall strategy of cell regulation. This, combined with the requirement for the pathway's close regulation, makes it effectively impossible to replace coenzyme A by a combination of simultaneous mutations or sequence of mutations and it should indeed remain invariant during evolution. The universality of coenzyme A is therefore consistent with its identified role, and supports the systems analysis identifying the doshas. Their systems functions survive developmental transformations of evolution with recognizable continuity. By virtue of that, vata, pitta, and kapha can be identified with them in all species.

Coenzyme A↗
PubMed1986

Morphometric requirements for image analysis and the IBAS interactive automatic image analysis system.

The morphometric demands made on an image analysis system are discussed, as is the IBAS interactive automatic system, which meets those requirements. The modular design of the IBAS image analysis system, with its tailor-made processors for image processing, system control and pattern recognition, gives speed and flexibility. The IMAGE image analysis language guarantees user friendliness, and, last but not least, the enormous amount of software offers accurate, reproducible measurements and dedicated evaluation programs.

Computers↗
PubMed1992

Multicentre evaluation of the Boehringer Mannheim/Hitachi 747 analysis system.

Analytical performance and practicability of the new Boehringer Mannheim/Hitachi 747 analysis system were assessed in a multicentre evaluation involving four laboratories. The analytical performance was evaluated according to a protocol similar to the ECCLS guidelines and comprised 13 analytes including enzymes, substrates and electrolytes. About 65,000 results were obtained within three months. The evaluation was planned and supported by a program system called "Computer Aided Evaluation". Acceptance criteria have been established for judging the results. The median of the within-run coefficients of variation (CVs) in control sera of all methods was below 1%, being far below the acceptance limit of 2%. The median of CVs of between-days imprecision was below 2% (acceptance criterion 3%). The high degree of precision prompted us to set up a biometrical model suitable for the differentiation between deviant points, outliers and measurements that can still be explained by the system performance. No relevant drift effects were observed during eight hours. The methods were linear over a wide range, avoiding rerun analysis in most cases. No sample-related carry-over was found. Reagent-dependent carry-over outside the acceptance limits was measured from uric acid to phosphorus to a slight extent, and from triacylglycerols to lipase, as well as from total protein to bilirubin to a perceptible degree. It can be avoided by separating these reagent combinations in the channel arrangement. Taking a systematic deviation of more than 10% as unacceptable, four of the 13 analytes suffered from interference by haemoglobin, one by bilirubin and one by turbidity. The Boehringer Mannheim/Hitachi 747 analysis system is capable of determining serum indices which in combination with the interferogram allow an assessment of the interference. With the exception of chloride the recovery of the assigned values for all control sera showed values between 95 and 105%. Out of 40 method comparison studies for enzymes and substrates, 31 yielded regression equations with less than 5% proportional errors and less than 5% constant errors. Deviations exceeding these acceptance criteria can be explained by differences in the reagent formulation, in the method employed or in calibration. The agreement of the ISE method comparisons was within a +/- 5% deviation over a wide analytical range. Practicability of the Boehringer Mannheim/Hitachi 747 analysis system was assessed with the help of a questionnaire, in which properties of the instrument were quantified, thus permitting a relatively objective rating. The 190 questions were placed in 14 groups, each dealing with an attribute of the instrument.(ABSTRACT TRUNCATED AT 400 WORDS)

Autoanalysis↗
PubMed2006

Comparison of the microsatellite instability analysis system and the Bethesda panel for the determination of microsatellite instability in colorectal cancers.

Microsatellite instability (MSI) analysis of colorectal cancers is clinically useful to identify patients with hereditary nonpolyposis colorectal cancer (HNPCC) caused by germline mutations of mismatch repair genes. MSI status may also predict cancer response/resistance to certain chemotherapies. We evaluated the MSI Analysis System (Promega Corp.; five mononucleotide and two pentanucleotide repeats) and compared the results to the Bethesda panel, which interrogates five microsatellite loci recommended by the 1997 National Cancer Institute-sponsored MSI workshop (three dinucleotide and two mononucleotide repeats). Thirty-four colorectal cancers were analyzed by both assays. The overall concordance between the two assays was 85% (29 of 34). There was complete concordance between the two assays for all of the MSI-high (11 of 11) and microsatellite stable (MSS; 18 of 18) cases. In the 11 MSI-high cases, all 5 of the mononucleotide loci in the MSI Analysis System demonstrated shifted alleles (100% sensitivity), and each shift resulted in products that were smaller in size than the germline alleles. All (5 of 5) of the cases interpreted as MSI-low by the Bethesda assay were interpreted as MSS by the MSI Analysis System. Our results suggest that the MSI Analysis System is generally superior and may help resolve cases of MSI-low into either MSI-high or MSS.

Case-Control Studies↗
PubMed1994

Reproducibility study of posterior subcapsular opacities on the NEI retroillumination image analysis system.

We developed a semi-automated retroillumination image analysis system which combines speed, ease of operation and interactive analysis. The system measures cataract area and integral of cataract density (ID). For system reproducibility evaluation, 20 eyes with posterior subcapsular opacities were captured twice by two photographers. Variability was estimated under a random effects analysis of variance model. Measurement errors for area and for ID were each small contributors to total variability (the sum of variability between study eyes plus measurement error), being 0.4% and 0.1% respectively. The largest contributor to area measurement error was image analysis variability (97%). For ID measurement error, the variability in images (44%) and in image analysis (46%) were major contributors. The reproducibility is comparable to previously described retroillumination analysis systems. This easy to use system may therefore be useful in clinical research studies including possible clinical trials of anti-cataract drugs.

Adolescent↗
PubMed1997

Clinical experience with the Diametrics IRMA (Immediate Response Mobile Analysis) blood analysis system.

The Immediate Response Mobile Analysis (IRMA) blood analysis system (Diametrics Medical Incorporated, St Paul, MN, USA) is a new point-of-care testing device that uses technology similar to the Gem Premier (Mallinckrodt Sensor Systems Incorporated, Ann-Arbor, MI, USA), which are ion-specific electrodes. We compared these two analysers using both patient blood samples (n = 50) and aqueous quality control solutions (n = 45). Linear regression (Pearson product-moment correlation coefficient) was performed to quantify the strength of the association between results. In addition, bias and precision were determined in accordance with the method described by Bland and Altman. The results demonstrated excellent correlation between the IRMA and the Gem Premier, and bias and precision were acceptable for both patient and quality control samples. Reproducibility of results was also assessed using one level of aqueous quality control solution (n = 50). The IRMA demonstrated very little variance in parameter readings over a five-day study period.

Blood↗
PubMed2002

Analyzing medical dialogues: strength and weakness of Roter's interaction analysis system (RIAS).

Roter's interaction analysis system (RIAS) is analyzed in this article. Ground rules of linguistic interaction analysis, emphasizing meaning as a product of interaction and turn taking as a basic principle for the understanding of interaction are briefly introduced. Specific aspects of the application of RIAS are discussed and a number of adjustments and/or specifications suggested: (1) utterances should be defined in terms of content and turn taking criteria; (2) the recording system should allow for registering interruptions; (3) pauses or silences should be scored on the basis of functional criteria and not as demarcation in the communication; (4) clear distinctions should be made between the categories of "backchannel" and "agree"; (5) questions should be coded according to function rather than linguistic form; (6) some of the socioemotional categories may appear too narrow, others too wide; (7) crying should be included in the coding scheme as a separate category.

Communication↗
PubMed2004

Learning the organization: a model for health system analysis for new nurse administrators.

Health systems are large and complex organizations in which multiple components and processes influence system outcomes. In order to effectively position themselves in such organizations, nurse administrators new to a system must gain a rapid understanding of overall system operation. Such understanding is facilitated by use of a model for system analysis. The model presented here examines the dynamic interrelationships between and among internal and external elements as they affect system performance. External elements to be analyzed include environmental factors and characteristics of system clientele. Internal elements flow from the mission and goals of the system and include system culture, services, resources, and outcomes.

Attitude of Health Personnel↗
PubMed2006

Systems analysis as support for decision making towards sustainable municipal waste management--a case study.

During the last decade, systems analysis has become a more frequently used tool in municipal waste management. This paper investigates how one such analysis, carried out in a Swedish county, was perceived by local municipal officers and politicians as support in the decision-making process. A questionnaire was sent to municipal officers and politicians in local government committees and municipal councils. The respondents considered the most important aspects in evaluating scenarios to be: possibilities for municipal co-operation to minimize cost and negative environmental influence; sound working conditions for refuse disposal personnel; low emissions of greenhouse gases; keeping household economy in mind; and using technologies that are known and reliable. Aspects of relatively low importance were the number of locally generated job opportunities, and minimizing work efforts for the households. The study also showed differences between male and female respondents and between politicians and municipal officers, on how scenarios were valued and on which aspects of the systems analysis were of greatest importance for this valuation. Respondents, on average, were satisfied with the systems analysis, and its usefulness as a decision-support tool. However, more work should be carried out to explain and present the results of the systems analysis to further improve its usefulness.

Conservation of Natural Resources↗
PubMed2003

Comparative analysis of the Cosmed Quark b2 and K4b2 gas analysis systems during submaximal exercise.

AIM: The purpose of this study was to compare the Cosmed K4b2 portable gas analysis system with the Cosmed Quark b2 metabolic cart. METHODS: Twenty-one subjects attended one testing session that consisted of duplicate measurements of gas volumes and concentrations using both Cosmed gas analysis systems at 3 treadmill work rates; 1) 80m x min(-1), 0% grade, 2) 80m x min(-1), 5% grade, and 3) 80m x min(-1), 10% grade. Subjects walked for 3 min at each rate with one of the gas analysis systems attached to the facemask. The order of the procedures was randomized so that one system was used during both phases (1st or 2nd) of each work rate. RESULTS: The results indicated that oxygen consumption (VO2) was significantly higher in the K4b2 compared to the Quark at 80m x min(-1), 0% grade (14.3+/-1.2 vs 13.6+/-1.2ml x kg(-1) x min(-1), respectively), (p<0.01). The fractional concentration of oxygen in expired air was also significantly lower in the K4b2 at 80 m x min(-1), 0% grade and 80 m x min(-1), 10% grade (p<0.05). There were no significant differences between systems for minute ventilation or carbon dioxide production. Despite the small mean bias in mean VO2 values (0.5-1.0ml x kg-1 x min(-1) higher) in the K4b2, all individual values were within the limits of agreement (mean difference+/-2 SD) as determined by the Bland-Altman technique. CONCLUSION: The findings show a minimal bias in respiratory and metabolic parameters during bi-pedal locomotor activities at low to moderate exercise intensities in the two gas analysis systems.

Adult↗
PubMed1993

A physiological and system analysis hybrid pharmacokinetic model to characterize carbon tetrachloride blood concentrations following administration in different oral vehicles.

Oral absorption of chemicals can be influenced significantly by the administration vehicle or diluent. It has been observed that the oral absorption of carbon tetrachloride (CCl4) and other volatile organic chemicals is markedly affected by the dosing vehicle, with administration in oils producing erratic blood concentration-time profiles with multiple peaks. Analysis of this type of data by a compartmental modeling approach can be difficult, and requires numerous assumptions about the absorption processes. Alternatively, a system analysis method with few assumptions may provide a more accurate description of the observed data. In the current investigations, a nonlinear system analysis approach was applied to blood CCl4 concentration-time data obtained following iv and oral administration. The oral regimens consisted of 25 mg CCl4/kg body wt given as an aqueous emulsion, in water, as pure chemicals, and in corn oil. The system analysis procedure, based upon a disposition decomposition method, provided an absorption input rate function, F, for each regimen. A physiological pharmacokinetic model, based primarily on parameters available in the literature, and the F input functions, formed a hybrid model that adequately described the observed blood CCl4 concentration-time data. The same physiological pharmacokinetic model, employing conventional first-order absorption input schemes, did not predict the data as well. Overall, the system analysis approach allowed the oral absorption of CCl4 to be characterized accurately, regardless of the vehicle. Though system analysis is based on general mathematical properties of a system's behavior rather than on its causal mechanisms, this work demonstrates that it can be a useful adjunct to physiological pharmacokinetic models.

Administration, Oral↗
PubMed2003

Integration of chemical and biochemical analysis systems into a glass microchip.

This review focuses on the integration of chemical and biochemical analysis systems into glass microchips for general use. By combining multiphase laminar flow driven by pressure and micro unit operations, such as mixing, reaction, extraction and separation, continuous-flow chemical processing systems can be realized in the microchip format, while the application of electrophoresis-based chip technology is limited. The performances of several analysis systems were greatly improved by microchip integration because of some characteristics of microspace, i.e., a large specific interface area, a short molecular diffusion time, a small heat capacity and so on. By applying these concepts, several different analysis systems, i.e., wet analysis of cobalt ion, multi-ion sensor, immunoassay, and cellular analysis, were successfully integrated on a microchip. These microchip technologies are promising for meeting the future demands of high-throughput chemical processing.

Biosensing Techniques↗
PubMed2002

Cell analysis system based on compact disk technology.

BACKGROUND: A cell analysis system was developed to enumerate and differentiate magnetically aligned cells selected from whole blood. The cellular information extracted is similar to the readout of musical information from a compact disk (CD). Here we describe the optical design and data processing of the system. The performance of the system is demonstrated using fluorescent-labeled cells and beads. Materials and Methods System performance was demonstrated with 6-microm polystyrene beads labeled with magnetic nanoparticles and allophycocyanin (APC) and immunomagnetically aligned leukocytes, fluorescently labeled with Oxazine750 and CD4-APC, CD8-Cy5.5, and CD14-APC/Cy7 in whole blood. RESULTS: The sensitivity of the system was demonstrated using APC-labeled beads. With this system, beads containing 333 APC molecules could easily be resolved from the background. This level of sensitivity was not achievable with a commercial flow cytometer. A maximum of 20,000 immunomagnetically labeled cells could be aligned and analyzed in between 0.6 m of Ni lines, distributed over a surface area of 18 mm(2) and extracted from a blood volume that depended on the height of the chamber. The utility of the system was demonstrated by performing a three-color CD4-CD8-CD14 assay. CONCLUSIONS: We built a cell analysis system based on immunomagnetic cell selection and alignment and analysis of fluorescent signals employing CD-technology that is as good or better than current commercial analyzers. The cell analysis can be performed in whole blood or any other type of cell suspension without extensive sample preparation.

Animals↗