SEARCH · PubMed Health

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.

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

At least 55 records · Page 3Linked to original sources

PubMed1992

Systems analysis of the carotid sinus baroreflex system using a sum-of-sinusoidal input.

The purpose of the present study was to determine the dynamic characteristics of the carotid sinus baroreflex system (CS) employing systems analysis. In 28 anesthetized and mechanically ventilated dogs with vagotomy, intracarotid sinus pressure (ICSP) was changed artificially. In protocol 1 (n = 7), we estimated the transfer function of the CS by means of a single sinusoidal input (SIN), the Gaussian white-noise input (GWN), and a sum-of-sinusoidal input (SUM). The transfer function of ICSP to systemic arterial pressure (SAP) was second-order delay with an identical corner frequency of 0.025 Hz and damping ratio of 0.7. The steady-state gain estimated using GWN (1.12 +/- 0.13) or SUM (1.13 +/- 0.08) was significantly smaller than SIN (1.69 +/- 0.25). In protocol 2, to find the reason why there was a difference among the estimated steady-state gains, we investigated the effect of ICSP pulsation on the open-loop gain of the CS. The maximum gain of the gain curve was decreased and the operating range was increased significantly with the 2-Hz pulsation. We could simulate the above phenomena by using a model with a nonlinear sigmoidal relationship between ICSP and SAP. The dynamic characteristics of the CS appeared to be changed by pulsation, but this phenomenon was attributable to the sigmoidal nature of the relationship between ICSP and SAP. Pulsation decreases the maximum gain and increases the operating range, which may contribute to stability of the CS and homeostasis of SAP.

Animals↗

PubMed1983

A computerized nasal analysis system.

Critical analysis of an aesthetic surgeon's presurgical and postsurgical photographs may provide an excellent tool for self-assessment, research, and teaching. Techniques are presented that allowed precise definition by personnel other than the surgeon of each patient's deformities and the effects of surgery on them. Trigonometric formulas were developed and a computer was programmed to use the X and Y coordinates for facial landmarks to perform many calculations providing distances, angles, projections, and rotations relating to the rhinoplastic surgery. Cases are reported showing typical changes and some results not readily apparent in the photographs. Such data provide not only current analysis of individual cases, but they eventually will become a large data base that may be used to select groups of rhinoplastic cases having common degrees of deformity or of postoperative changes.

Anthropometry↗

PubMed1990

The technique of gait analysis using a Coda-3 motion analysis system.

Gait analysis using Code-3 provides information which allows individual gait to be characterised with little interference to the patient. It is an ideal method for analysing gait in patients with cerebral palsy. Because of the ease with which this information is now available using Coda-3, gait analysis can now be performed on all ambulant patients in whom surgery is contemplated.

Biomechanical Phenomena↗

PubMed1983

Nutrient Analysis System--a computerized seven-day food record system.

A self-recording, directly computer-readable, seven-day food record system (the Nutrient Analysis System [NAS]) was developed using the National Heart, Lung, and Blood Institute Food Table as a data bank for the nutrient analysis. This article describes the system and reports the results of a study which evaluates the system in an experimental setting. It is concluded that the Nutrient Analysis System is no less accurate or biased than the traditional written food record method under the conditions of this test. Additionally, NAS is a system which allows for efficient use of professional time and immediate availability of nutrient analysis for use in counseling.

Adult↗

PubMed2001

Systems analysis and design methodologies: practicalities and use in today's information systems development efforts.

Historically, systems analysis and design methodologies have been used as a guide in software development. Such methods provide structure to software engineers in their efforts to create quality solutions in the real world of information systems. This article looks at the elements that constitute a systems analysis methodology and examines the historical development of systems analysis in software development. It concludes with observations on the strengths and weaknesses of four methodologies and the state of the art of practice today.

Computer-Aided Design↗

PubMedDate not supplied

Interstitial lung diseases: evaluation of the performance of a computerized analysis system versus observers.

We have been developing a computerized analysis system to detect interstitial lung abnormalities on chest radiographs. In this study, we evaluated the performance of our computerized analysis system and compared it with that of radiologists. The performance of the computerized analysis system was inferior to the mean performance of the chest radiologists. However, the performance of the computerized analysis system was superior to the mean performance of the residents. From our results, the outputs obtained from the computerized analysis system can be used by radiologists as a "second opinion", and this system could be especially useful to obtain quantitative data for follow-up of known interstitial lung diseases.

Adult↗

PubMed2002

The Roter interaction analysis system (RIAS): utility and flexibility for analysis of medical interactions.

The Roter interaction analysis system (RIAS), a method for coding medical dialogue, is widely used in the US and Europe and has been applied to medical exchanges in Asia, Africa, and Latin America. Contributing to its rapid dissemination and adoption is the system's ability to provide reasonable depth, sensitivity, and breadth while maintaining practicality, functional specificity, flexibility, reliability, and predictive validity to a variety of patient and provider outcomes. The purpose of this essay is two-fold. First, to broadly overview the RIAS and to present key capabilities and coding conventions, and secondly to address the extent to which the RIAS is consistent with, or complementary to, linguistic-based techniques of communication analysis.

Communication↗

PubMed1987

A computerized diet analysis system for the research nutritionist.

A computerized diet analysis system can assist in the many dietary computations performed daily by the research nutritionist. When selecting a computerized diet analysis system, the research nutritionist must consider present and future needs and select a system that is accurate, efficient, and cost-effective. The purpose of this article is to review the computer needs of the research nutritionist, identify areas to be considered when selecting a diet analysis system, and describe a system that functions easily in research or clinical settings. The diet analysis system described here is interactive and easy to use and provides flexible programming to accommodate changing research or clinical needs. The nutrient data base is accurate, verified, and periodically updated by the company that provides the system. Data entry is easy, and new foods or recipes can readily be added to the nutrient data base. The system's programs and special features provide efficient, accurate methods for creating and analyzing complex research diets, analyzing nutrient intake, and reporting nutrient data.

Computer Systems↗

PubMed1995

Image quality in digital chromosome analysis systems.

This paper reports on an investigation into the differences in image quality of different components used in a digital image processing system for chromosome analysis. As chromosome aberrations are important tools in the cloning of genes, it is important to know if the introduction of computerized analysis systems increases the risk of missing small aberrations. In this investigation the number of visible bands on a number of chromosomes has been used as a measure of quality. The images compared are microscope ocular images, photographs from a microscope built-in camera, digital images from a high and from a standard resolution camera, presented both on screen and print-out on paper. The main conclusions are that: (1) the view in the microscope ocular gives the best resolution, (2) there are risks of losing vital information using the digital image processing system for chromosome analysis, and (3) this risk is significantly reduced when using a high resolution camera.

Chromosome Banding↗

PubMed2004

Systems analysis in environmental engineering: how far should we go?

Systems analysis is identified as a unifying topic of environmental engineering. Based on a questionnaire sent out to peers and based on the experience with an advanced systems analysis course the possible content and association of the content with bachelor and master's programs is discussed. At the bachelor's level it is concluded that an array of topics should be introduced more in an inductive way, going along with the discussion of examples. At the master's level it is suggested that a substantial course, which systematically introduces a broad variety of systems analysis tools, is provided. Such a course should go along with the introduction of a simulation tool, which supports application of systems analysis methods.

Curriculum↗

PubMed1990

Retinal nerve fiber layer analysis by a computerized digital image analysis system.

A computerized digital image analysis system was developed to evaluate the retinal nerve fiber layer (RNFL) by red-free fundus photography. The image intensity of the RNFL was computed for 30 degrees between the disc and macula. Thirty early open-angle glaucoma patients and 30 normal age-matched subjects were examined. The coefficients of variation in the reproducibility of the measurements in normal subjects were 7.3 to 9.9% for the interphotographic studies, and 4.1 to 5.1% for the intraphotographic studies. Using this new image analysis system, the RNFL changes were detected easily and the glaucomatous eyes were distinguished from normal eyes with high sensitivity and specificity, 95% and 80%, respectively. This method will be useful for diagnosis of glaucoma at a very early stage.

Aged↗

PubMed2004

Technical note: A toy as tool: a low-cost image analysis system for the evaluation of tumor size in experimental small animal models.

Image analysis systems are an essential tool in measurements of size of intraparenchymal tumors or lesions in experimental small animal models. Conventional image analysis systems are relatively expensive. We therefore compared the performance of a professional image analysis system with an inexpensive setup by evaluating tumor size in an orthotopic glioma mouse model. The maximum cross-sectional tumor area of H&E stained brain-slides of two groups of mice (treatment and control group) was measured by two independent investigators using a professional image analysis system (Leica DM IRB microscope) with the Leica Quantimet 500c software, and a low-cost-system (Intel QX3 microscope) with a non-commercial image analysis software. Mean tumor volumes were calculated and the results from each of the image analysis systems, investigators, and treatment effects were compared. The tumor volumes as measured with the low-cost and the professional system differed between -3.7 and +7.5% (P = 0.69-0.99). Measurements made by investigator A and B differed between -7.0 and +3.9% (P = 0.69-0.88). Treatment in all cases significantly reduced the tumor volume between 58.4 and 62.7% (P = 0.0002 or 0.0003), regardless of the investigator or the used image analysis system. We therefore conclude that the QX3 low-cost microscope in combination with a non-commercial image-analysis software represents an inexpensive solution to reliably analyze the size of regions of interest, if they provide a sufficient contrast. However, the low-cost setup due to its low resolution definitely limits a detailed analysis of histologic features.

Animals↗

PubMedDate not supplied

[An analysis of the tumor growth rate in neuroma of the VIII cranial nerve using a digital image analysis system].

A digital image analysis system was used in a retrospective analysis of MRI findings in 9 patients with acoustic neuroma. Maximum and minimum tumor diameters and surface area were measured and tumor volume was calculated. All studies included intravenous injection of gadolinium (Gd-DTPA or DOTA) and axial and coronal sections. Tumoral growth rate was analyzed using the increase in tumor size ( T) tumor area doubling time (ADT), and tumor volume doubling time (VDT). The purpose of this study was to document the growth rate of acoustic neuromas with periodic MRI. In an era in which preservation of hearing and the facial nerve is a goal of acoustic neuroma surgery, knowledge of tumor growth rate should improve patient care.

Aged↗

PubMed2003

[Application of image analysis system to the study of biomedicine].

Image analysis plays an important role in morphological study of tissues and cells and their quantitative analysis. It also contributes to clinical pathological diagnosis. With the rapid development of computer technology great progress has been made in the image analysis system, its measurement, rapidity, accuracy and the extent of automation have been greatly enhanced. In the meantime advances in medicine give impetus to its improvement. In this paper, the process of development, the basic structure and mechanism of image analysis system are discussed and the application of image analysis system to the study of biomedicinal is presented.

Image Processing, Computer-Assisted↗

PubMed1983

Computerized dietary analysis systems: a comparative view.

The computerized dietary analysis system that was in use at Tufts University/Frances Stern Nutrition Center and two commercially available systems were compared in a study examining differences between systems. Content, software, data base maintenance, and cost were among the characteristics in which they differed. Calculations on three-day food records provided by five omnivore and five vegetarian women differed from one system to the next. Significant differences were noted for total kilocalories, total fat, saturated fatty acids, polyunsaturated fatty acids, cholesterol, and phosphorus. Unfortunately, it was not possible to describe the degree to which each of the many possible causes of variability may have contributed to the differences in nutrient calculations. However, coding activity did not appear to influence nutrient calculations within one system in a significant manner when skilled coders were employed. We conclude that differences observed in dietary studies using different computerized dietary analysis systems may be due in part not to real differences in subjects but rather to the system employed. Valid reference standards against which each nutrient value can be compared to ascertain exactly what these errors are do not exist. All the information consumers need to make useful comparisons among the various computerized dietary analysis systems is not yet available in a standardized format and is eagerly awaited by this and other groups.

Adult↗

PubMed1997

Functional coupling of Gi subtype with GABAB receptor/adenylyl cyclase system: analysis using a reconstituted system with purified GTP-binding protein from bovine cerebral cortex.

A single molecular species of GTP-binding protein (G protein) has been purified from the bovine cerebral cortex. The immunoblot analysis indicated that the isolated G protein might be Gi1 or Gi2 but not Go, since it was reacted by specific antibodies, anti-Gi alpha 1-2 and anti-Gi alpha 1-1, but not anti-Go alpha. When the Gi protein was reconstituted into phospholipid vesicles with partially purified GABAB receptor and adenylyl cyclase, the stimulation of GABAB receptor by its agonists induced the inhibition of forskolin-stimulated cAMP accumulation. This GABA-induced inhibition was abolished by CGP 55845A, an antagonist of GABAB receptor. These results suggest that a Gi subtype, which was suggested to correspond to Gi1 or Gi2 may be functionally coupled with GABAB receptor/adenylyl cyclase system.

Adenylyl Cyclases↗

PubMed2000

Quantitative Evaluation of Nystagmus by an Image-analysis System.

Purpose: We attempted to apply a newly developed image-analysis system for measurement and analysis of nystagmus.Method: Eye movements were recorded by digital video through a head-mounted charge coupled device (CCD) camera. The recorded movie was converted into black and white in order to detect the area of the pupil. Horizontal and vertical eye positions were determined by calculating the centroid of the pupil. Torsional angle was calculated using the iris striate pattern around the pupillary margin.Results: The parameters (amplitude, cycle, etc.) of nystagmus were calculated easily by the new image-analysis system from the recorded images. As examples, the foveation period was measured accurately in a case of jerky-type congenital nystagmus. Very regular cycles of intorsional attack period were revealed in a case of superior oblique myokymia. A case of cork-screw-like nystagmus showed a characteristic combination of large and small cycles unassociated with torsion.Conclusion: This image-analysis system was useful for quantitative analysis of nystagmus, and especially for measurement of torsion. Detailed waveforms and specific rhythms of nystagmus, which could not be recognized by observation, were demonstrated by this system.

Journal Article↗

PubMed2000

[Quantitative evaluation of nystagmus by an image-analysis system].

PURPOSE: We attempted to apply a newly developed image-analysis system for measurement and analysis of nystagmus. METHOD: Eye movements were recorded by digital video through a head-mounted charge coupled device (CCD) camera. The recorded movie was converted into black and white in order to detect the area of the pupil. Horizontal and vertical eye positions were determined by calculating the centroid of the pupil. Torsional angle was calculated using the iris striate pattern around the pupillary margin. RESULTS: The parameters (amplitude, cycle, etc.) of nystagmus were calculated easily by the new image-analysis system from the recorded images. As examples, the foveation period was measured accurately in a case of jerky-type congenital nystagmus. Very regular cycles of intorsional attack period were revealed in a case of superior oblique myokymia. A case of cork-screw-like nystagmus showed a characteristic combination of large and small cycles unassociated with torsion. CONCLUSION: This image-analysis system was useful for quantitative analysis of nystagmus, and especially for measurement of torsion. Detailed waveforms and specific rhythms of nystagmus, which could not be recognized by observation, were demonstrated by this system.

Adult↗