Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Systems Analysis”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 559 records · Page 31Linked to original sources
PubMed2002

Applicability of a computer-assisted image analysis system for the evaluation of gingival status in subjects from Asian and Caucasian backgrounds.

We have recently developed a computer program to allow the automatic evaluation of the degree of gingival inflammation. The aim of the present study was to determine the efficiency of our system, which consisted of a digital camera, computer and our original program, in a sample population of various ethnic backgrounds. Digital images of frontal views of maxillary incisors were taken for 141 subjects and then subjected to computer-assisted analysis to determine the degree of redness (colorimetric assessment) and swelling (morphometric assessment) and was compared with the visual assessment of the PMA gingival score. The age of subjects ranged from 19 to 65 (Mean 33.9 SD12.8), and consisted of slightly more females (81) than males (60). Within the study group 78% of subjects classified themselves as Caucasian (European, South American, Middle Eastern), 21% were Asian or Pacific Islander, and 1% was African. The subjects were separated into 9 groups according to their PMA score. In addition, colorimetric and morphometric score were plotted against each other. The colorimetric scores ranged between 55.1 to 64.8 (arbitrary units) and morphometric scores ranged between 0.175 to 0.313 (arbitrary units). There were no ethnic differences with respect to colour and contour when two groups of European (90) and Asian (17), who were scored as 000 using the PMA index, were compared. There was no significant correlation between PMA score and morphometric score (P = 0.0711), but the correlation coefficient between PMA score and colorimetric score was 0.130 (P = 0.0122). Comparison of the highly scored image samples and the lower scored images with the visual assessment codes showed very good correlation. These preliminary findings suggest that the developed computer-assisted image analysis system shows promise for assessing gingival inflammation via an automated method.

Adult↗
PubMed2006

Phenotypic comparison of allopatric populations of Fasciola hepatica and Fasciola gigantica from European and African bovines using a computer image analysis system (CIAS).

The quantification of the different sizes and shapes of Fasciola hepatica and Fasciola gigantica from bovines has been achieved for the first time in natural allopatric populations. Linear measurements, areas and ratios of gravid adults and eggs of F. hepatica (from France and Spain) and F. gigantica (from Burkina Faso) were analysed using a computer image analysis system and an allometric model: (y2m - y2)/y2 = c[(y1m - y1)/y1](b), where y1 = body area or body length, y2 = one of the measurements analysed, y1m, y2m = maximum values towards which y1 and y2, respectively, tend and c, b = constants. All the measurements overlap in the two fasciolids, apart from the distance between the ventral sucker and the posterior end of the body, body roundness and body length/body width ratio. The results obtained may be useful in Fasciola species identification in countries where both species coexist.

Africa↗
PubMed1986

A new gait analysis system for clinical use in a rehabilitation center.

A semi-portable system based on a microcomputer has been developed to measure the vertical reaction forces on both feet during walking. Eight capacitive force transducers are attached to each sole of the patients' shoes. This allowed the forces to be measured for several consecutive steps during a walk of 20 sec. This article describes the principles of operation of the force transducers and the associated electronic system. It also shows data processing procedures and gives a review of the available methods of data presentation. Recordings of the walking pattern of three patients with different diagnostics are presented and discussed to demonstrate the usefulness of the new gait analysis system in a rehabilitation center.

Adult↗
PubMed1992

Development and distribution of the white blood cells within various structures of the human menstrual corpus luteum examined using an image analysis system.

PROBLEM: Emerging evidences suggest that immunoendocrine interactions play definitive roles during development and regression of the human menstrual corpus luteum (hmCL). We have studied the distribution of immune cells within individual structures of hmCL during various stages of its development. METHOD: Immunoperoxidase-stained ultra-thin frozen sections were evaluated using light microscopy fitted with an image analysis system. RESULTS: The results suggest that monocytes/macrophages and MHC class II positive cells are the most prominent immune cells within the hmCL throughout its whole lifespan. Both cell types are concentrated within the trabeculae. In addition, MHC class II positive cells are abundant also within the granulosa-luteal layer. T helper/inductor (Th/i) and T cytotoxic/suppressor (Tc/s) cells were detected only in minor amounts within the thecal trabeculae of mature tissue. CONCLUSIONS: Possible links between the occurrence and functional roles of the immune cells studied are discussed.

Antigens, CD↗
PubMed2002

Online evaluation of a commercial video image analysis system (Computer Vision System) to predict beef carcass red meat yield and for augmenting the assignment of USDA yield grades. United States Department of Agriculture.

Objective quantification of differences in wholesale cut yields of beef carcasses at plant chain speeds is important for the application of value-based marketing. This study was conducted to evaluate the ability of a commercial video image analysis system, the Computer Vision System (CVS) to 1) predict commercially fabricated beef subprimal yield and 2) augment USDA yield grading, in order to improve accuracy of grade assessment. The CVS was evaluated as a fully installed production system, operating on a full-time basis at chain speeds. Steer and heifer carcasses (n = 296) were evaluated using CVS, as well as by USDA expert and online graders, before the fabrication of carcasses into industry-standard subprimal cuts. Expert yield grade (YG), online YG, CVS estimated carcass yield, and CVS measured ribeye area in conjunction with expert grader estimates of the remaining YG factors (adjusted fat thickness, percentage of kidney-pelvic-heart fat, hot carcass weight) accounted for 67, 39, 64, and 65% of the observed variation in fabricated yields of closely trimmed subprimals. The dual component CVS predicted wholesale cut yields more accurately than current online yield grading, and, in an augmentation system, CVS ribeye measurement replaced estimated ribeye area in determination of USDA yield grade, and the accuracy of cutability prediction was improved, under packing plant conditions and speeds, to a level close to that of expert graders applying grades at a comfortable rate of speed offline.

Animals↗
PubMed2002

Proliferating cell nuclear antigen assessed by a computer-assisted image analysis system in patients with chronic viral hepatitis and cirrhosis.

BACKGROUND: Assessment of liver cell proliferation by immunodetection of proliferating cell nuclear antigen may predict regenerative potential and survival of liver and hepatocellular carcinoma risk in patients with chronic viral hepatitis. AIM: To evaluate proliferating cell nuclear antigen status and its clinical significance in a large cohort of patients with chronic viral hepatitis and different degree of liver damage by a computer assisted imaging analysis system. MATERIALS: Liver biopsies from 358 patients with chronic hepatitis (259 males, 49 years, 63% with hepatitis C infection, 27% with hepatitis B virus, 10% with multiple infections) were studied. METHODS: Proliferating cell nuclear antigen was localised by immunoperoxidase on microwave oven pre-treated formalin-fixed, paraffin embedded sections using PC10 monoclonal antibody. Proliferating cell nuclear antigen labelling index was calculated by an automated imaging system (Immagini e Computers, Milan, Italy). RESULTS: Mean proliferating cell nuclear antigen labelling index ranged from 0.1% for patients with minimal changes to 3.6% for those with cirrhosis and hepatocellular carcinoma. Overall, proliferating cell nuclear antigen labelling index was higher in males, in older patients, in multiple infections and in hepatitis C virus compared to hepatitis B virus related cases. By linear regression analysis, proliferating cell nuclear antigen labelling index correlated with older age, male gender; higher transaminase levels, hepatitis C virus, higher histological gradIng and staging: by multivariate analysis male gender, hepatitis C virus, higher grading and staging resulted as independent variables. Both hepatitis C virus or hepatitis B virus cirrhotics had similar liver cell proliferation rate but those with hepatitis B virus had higher prevalence of liver cell dysplasia with respect to those with hepatitis C virus. CONCLUSIONS: Proliferating cell nuclear antigen labelling index was a reliable assay for assessing liver cell proliferation rate in patients with chronic viral hepatitis and correlated with liver disease severity

Adult↗
PubMed2003

Automatic quantitation of HIV-1 mediated cell-to-cell fusion with a digital image analysis system (DIAS): application for rapid screening of HIV-1 fusion inhibitors.

Human immunodeficiency viruses type 1 (HIV-1) mediated cell-to-cell fusion plays an important role in HIV-1 spread from infected cells to uninfected cells and in HIV-1 cytopathogenesis. In the present study, we developed a convenient cell fusion assay using a computer-controlled digital image analysis system (DIAS) for automatic quantitation. Compared with a manual quantitative method, DIAS automatic method is less laborious, and more rapid. Furthermore, it is more objective and less dependent on the researchers' experience. This method has great potential to be developed further as a high-throughput screening assay for rapid screening of HIV-1 fusion inhibitors, for evaluating the activity of HIV-1 entry inhibitors and for studying the mechanism of action of anti-HIV-1 agents.

Cell Fusion↗
PubMed2006

Communication between South Asian patients and GPs: comparative study using the Roter Interactional Analysis System.

BACKGROUND: The UK South Asian population has poorer health outcomes. Little is known about their process of care in general practice, or in particular the process of communication with GPs. AIM: To compare the ways in which white and South Asian patients communicate with white GPs. DESIGN OF STUDY: Observational study of video-recorded consultations using the Roter Interactional Analysis System (RIAS). SETTING: West Yorkshire, UK. METHOD: One hundred and eighty-three consultations with 11 GPs in West Yorkshire, UK were video-recorded and analysed. RESULTS: Main outcome measures were consultation length, verbal domination, 16 individual abridged RIAS categories, and three composite RIAS categories; with comparisons between white patients, South Asian patients fluent in English and South Asian patients nonfluent in English. South Asians fluent in English had the shortest consultations and South Asians non-fluent in English the longest consultations (one-way ANOVA F = 7.173, P = 0.001). There were no significant differences in verbal domination scores between the three groups. White patients had more affective (emotional) consultations than South Asian patients, and played a more active role in their consultations, as did their GPs. GPs spent less time giving information to South Asian patients who were not fluent in English and more time asking questions. GPs spent less time giving information to South Asian patients fluent in English compared with white patients. CONCLUSIONS: These findings were expected between patients fluent and non-fluent in English but do demonstrate their nature. The differences between white patients and South Asian patients fluent in English warrant further explanation. How much of this was due to systematic differences in behaviour by the GPs, or was in response to patients' differing needs and expectations is unknown. These differences may contribute to differences in health outcomes.

Adult↗
PubMed1979

"Blind focusing": an objective method for avoiding errors of focus at the television texture analysis system (TAS).

The amount of light energy a particle absorbs does not depend upon correct focus. The change in the path of light rays brought about by defocusing causes absorbing areas to be registered as areas of higher transmittance than when in focus. Already wellknown in photometry, this effect is put to use by the "blind focus" method at the television texture analysis system (TAS, Leitz). Some chromophores within the object to be measured are compared to a preset value of transmittance, for example T = 0.40. Only the area representing the structures as dense or denser than the preset density are registered. If the structures are out of focus the size of the registered area is too low, since by defocusing, structures to be measured become pale and diffuse, the correct focus corresponds to the largest area to a preset value of transmittance.

Amnion↗
PubMed1983

Quantification of characteristic blood-flow parameters in the vessels of the retina with a picture analysis system for video-fluorescence angiograms: initial findings.

Fluorescence angiograms of the retina were performed on 12 healthy, adult subjects between the ages of 20 and 52 years with a 30 degrees fundus camera (C. Zeiss), a low-light TV camera and a video recorder. Characteristic blood-flow parameters for the retina were obtained from the video recording using the picture-analysis system (Mikrovideomat 3, C. Zeiss). These included: the arm-retina time (ART), the arteriovenous passage time (AVP) and the arterial contrast-medium velocity (ACMV). Normal values for these parameters were derived for the four retinal quadrants and then discussed. In addition, the filling characteristics of venules were measured and discussed.

Adult↗
PubMed1991

The determination of thyroxine and thyroxine uptake with new homogeneous enzyme immunoassays using Boehringer Mannheim/Hitachi analysis systems.

New homogeneous enzyme immunoassays for the determination of thyroxine and thyroxine uptake have been developed. The CEDIA assays are based on the cloned enzyme donor immunoassay technology, which involves fragments of beta-galactosidase prepared by genetic engineering. The assays have been adapted for Boehringer Mannheim/Hitachi analysers. The CEDIA T4/T Uptake assays were evaluated in eleven clinical chemistry laboratories on various Boehringer Mannheim/Hitachi analysis systems, using a 2-point calibration. The analytical range of the T4 test was 10 to 258 nmol/l thyroxine. The T uptake test had a measuring range between 20-50%. Depending on the concentration of the analyte (samples from hypo-, eu- or hyperthyroid patients), mean coefficients of variation ranged from 1.8 to 4.8% within-run and from 4.1 to 6.5% between-run for the T4 assay. Even better coefficients of variation were obtained for the T uptake assay (1.4 to 2.3% within-run, 2.8 to 3.3% between run). The relative inaccuracy of the CEDIA assays with respect to values assigned by other tests was satisfactory in various control sera. The T4 assay was compared with one radioimmunoassay, one enzyme immunoassay and one fluorescence polarisation immunoassay. Slopes ranging from 0.9 to 1.1 and intercepts ranging from -10 to +10 nmol/l thyroxine were obtained with two exceptions. The results of the T uptake test correlated reasonably with those of other thyroxine-binding methods. No interference was observed with icteric and lipaemic sera. Haemoglobin up to 4 g/l had no significant influence. Results of the CEDIA T Uptake test are mainly used for calculation of the free thyroxine index, in which the thyroxine value is corrected for variations of thyroxine-binding protein concentrations.(ABSTRACT TRUNCATED AT 250 WORDS)

Autoanalysis↗
PubMed2005

Adapting the Roter interaction analysis system for telemedicine: lessons from four specialty clinics.

Four specialists (a child psychiatrist, an oncologist, a cardiologist and a rheumatologist) conducted telemedicine clinics using videoconferencing at a bandwidth of 128-384 kbit/s. The consultations were videorecorded. The coded interactions from the first two patients recruited from each of the four telemedicine clinics were analysed. Tapes were coded by two raters. We adapted the Roter interaction analysis system (RIAS) for the telemedicine context. Utterances were coded into socio-emotional and task-focused categories. There were 1055 utterances in total. Providers generated significantly more utterances across categories than patients. In the patient-provider interactions, only 2% of the total utterances related to the technology. The predominance of socio-emotional utterances compared with task-focused utterances for providers was contrary to our expectations. Further studies are required to establish the reliability of the adapted RIAS measure and to increase understanding of telemedicine communication patterns.

Child↗
PubMed1980

Correction for deadtime losses in a gamma camera/data analysis system.

In quantitative analyses of dynamic radionuclide studies, using large activities of 99mTc flowing through organs it is necessary to determine accurately count-rate losses and to provide appropriate corrections. A method is described for estimating deadtimes and applying corrections to the observed counting rates using a two component model where the gamma camera is considered to have a purely paralyzable deadtime and the data analysis system a purely non-paralyzable deadtime.

Radionuclide Imaging↗
PubMed2003

Intra-rater and inter-rater reliability of gait measurements with CODA mpx30 motion analysis system.

Variations between measurements of clinical outcomes sometimes result from observer errors and are not due to the therapeutic intervention. For the correct interpretation of clinical data it is, therefore, important to ascertain the reliability of the measurement methods used. In the present study we evaluated the test-retest and between observer reliability of gait measurements with the Cartesian Optoelectronic Dynamic Anthropometer (CODA mpx30) motion analysis system. Our findings suggest a better intra-rater and inter-rater reliability of kinetic than kinematic data. Disagreements between the investigators were most marked for the kinematic data, especially the hip angle, and disagreements were least for the spatio-temporal gait parameters. The poor reproducibility of kinematic variables may be due to problems with the accurate placement of markers on the surface anatomical landmarks.

Adult↗
PubMed2000

Use of an automated DNA analysis system (DARAS) for sequence-specific recognition of Neisseria meningitidis DNA.

OBJECTIVES: To combine use of the polymerase chain reaction (PCR) for rapid diagnosis of meningococcal meningitis with a novel automated detection system for sequence-specific recognition of PCR products. METHODS: DNA was extracted from cerebrospinal fluid (CSF) by a quick boil-lysis method, followed by PCR with primers specific for Neisseria meningitidis. Sequence-specific recognition of N. meningitidis DNA was performed with an automated DNA analysis system (DARAS) and the data were compared with results following agarose gel electrophoresis or conventional microbiological culture. RESULTS: The DARAS system had a sensitive detection limit of 102 meningococci/mL with spiked samples, compared with a detection limit of 104 meningococci/mL following agarose gel electrophoresis. When the system was used to examine 74 CSF samples, the 19 CSF samples positive for N. meningitidis by conventional microbiological methods were also all positive in the DARAS system and the 55 samples negative by DARAS for meningococci were also negative by conventional microbiological methods. CONCLUSION: The sensitivity and specificity of the DARAS system makes it a useful tool for the diagnosis of meningococcal meningitis. The system is user-friendly, requires minimal hands-on time and generates data in an informative numerical format.

Colony Count, Microbial↗
PubMed2004

Tooth size in patients with supernumerary teeth and a control group measured by image analysis system.

OBJECTIVE: The aim of this study was to compare tooth size measurements between patients with supernumerary teeth and a control group. METHOD: The supernumerary group consisted of 56 subjects (21 females and 35 males) and the control group of 40 subjects (20 females and 20 males). All available permanent teeth on the dental casts were imaged and measured from both buccal and occlusal views using an image analysis system. Mesio-distal, bucco-lingual or occluso-gingival dimensions, area and perimeter were measured from each view. RESULTS: Supernumerary tooth patients tended to have larger tooth size measurements for almost all variables than controls. Significant differences (p<0.05) were found for the mesio-distal dimension of the upper and lower incisors and the bucco-lingual dimensions of the lower first premolars. CONCLUSIONS: The results are compatible with supernumerary teeth being a complex dental anomaly with a multifactorial aetiology in which both genetic and environmental factors are important. There is some evidence of a local effect with greater differences in tooth dimension adjacent to the site of the supernumeraries.

Adolescent↗
PubMed1981

[Quantitative evaluation of an antiarrhythmic therapy (disopyramide) in patients with frequent premature ventricular contractions (PVC) using a computer-assisted long-term ECG analysis system (author's transl)].

15 patients (pts.) - 12 males, 3 females - with frequent PVC (greater than 3%/16 hr during a qualifying period = LP) of different causes underwent after one-day placebo application (PL) drug treatment (disopyramide: loading dose 600 mg, 300 mg t.i.d.) over two days (D1, D2). The ambulatory continuously recorded long-term ECG was analysed using "Multipass-Scanning", a computer-supported analysis system for quantification of therapeutic success. The mean PVC rate of 17% prior treatment could be diminished in 87% of the pts. significantly. 5 pts. (group I) demonstrated a maximal PVC-reduction rate of more than 90 rel %. Among them in 2 pts. the PVC-rate did not exceed the 1%-level during D1 and D2 demonstrating an optimal therapeutic success. The max. PVC-reduction rate ranged between 80 and 90 rel % in 3 pts. (group II) and between 38 and 78 rel % in 5 pts. (group III). 2 pts. did not respond on DP. The mean DP-plasma level was higher in group-III pts. than in group-I or -II pts. in spite of a less therapeutic success. 7 pts. demonstrated a circadian behaviour of PVCs. Therefore the circadian variability increased. Also lower PVC rates under DP (D1, D2) led to an increase of spontaneous variability of PVCs. The maximal PVC depressant effect of DP appeared while the heart rate was 70 b.p.m. or higher. In conclusion, 87% of the pts. demonstrated a drug effect, but an effective antiarrhythmic therapy occurred only in 2 pts. (13%). A decrease of the frequency of rhythm disturbances led to a decrease of arrhythmia's variability and requires a prolongation of the ECG-recording time to eliminate the variabilities of arrhythmia occurred (spontaneous, circadian) and to avoid a mimicked therapeutic success.

Adolescent↗
PubMed2007

Mechanism-based pharmacokinetic-pharmacodynamic modeling: biophase distribution, receptor theory, and dynamical systems analysis.

Mechanism-based PK-PD models differ from conventional PK-PD models in that they contain specific expressions to characterize, in a quantitative manner, processes on the causal path between drug administration and effect. This includes target site distribution, target binding and activation, pharmacodynamic interactions, transduction, and homeostatic feedback mechanisms. As the final step, the effects on disease processes and disease progression are considered. Particularly through the incorporation of concepts from receptor theory and dynamical systems analysis, important progress has been made in the field of mechanism-based PK-PD modeling. This has yielded models with much-improved properties for extrapolation and prediction. These models constitute a theoretical basis for rational drug discovery and development.

Drug Delivery Systems↗