Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Software Validation”

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 217 records · Page 12Linked to original sources
PubMed1992

A microcomputer program for determining turnover rates during non-steady state conditions: application to monoamine turnover.

A program to calculate the turnover rate of monoaminergic neurotransmitters was written for use on microcomputers. The program is based on non-steady state models, i.e., measuring the rate of change of levels of neurotransmitters or their metabolites after pharmacological inhibition of synthetic or degradative enzymes. Methods have been developed to estimate monoamine turnover by measuring the rate of decrease of catecholamine levels after treatment with alpha-methyl-p-tyrosine (AMPT), a tyrosine hydroxylase inhibitor, or the increase in serotonin levels after pargyline, an inhibitor of monoamine oxidase. This program is suitable for examining either linear increases or exponential decreases in monoamine levels. The program has been tested in our laboratory for the determination of serotonin, dopamine or norepinephrine turnover after hormonal or pharmacological manipulations. The program is readily adaptable for calculation of the turnover rate of other biological molecules under non-steady state conditions.

Biogenic Monoamines↗
PubMed1993

Preoperative assessment and prediction of postoperative results in an artificial arterial network using computer simulation.

A computer model has been developed that can be used to describe the human arterial system mathematically. It simulates the complex relationship of morphology and hydraulics in the vessel network. After entering patient data into a standard vessel model, the mean flow velocity, the flow direction, and the blood pressure at each specified point of the flow network can be calculated. The vessel picture can be altered and modified with the help of a graphic editor. Localized or diffuse stenoses, bypasses with simple or multiple anastomoses, end-to-end anastomoses, end-to-side anastomoses, etc., can be studied in terms of the hydraulic effects on the local situation or on the entire vessel system. Experimental results of ultrasonic mean flow data in vessel systems of leg and cerebral arteries of patients are compared with calculated values. The predicted and measured flow velocities show a mean difference of about 10% indicating that such a computer model may be successfully used in the optimal planning of bypass operations.

Arteries↗
PubMed1994

Hydrophobic neighboring homology (HNH) dotplot: an approach for assessing structurally similar motifs in proteins.

Structural biology needs sensitive tools to detect homology between proteins of low sequence identity, but with closely related 3-D structures. Using a conventional dotplot method, we therefore introduced 2 concepts to improve the search for similarities between secondary structures of analyzed proteins: 'hydrophobic neighboring homology' (HNH) and 'amino acid degeneracy classes'. The amino acids are grouped into 3 subsets: hydrophobic, hydrophilic and mimetic. A 'Neighboring Similarity Index' (NSI) is calculated for every residue pair and quantifies its neighbor homology. By thresholding the homology matrix and filtering the dotplot, the homologous patterns are extracted. We have evaluated the efficiency and limits of the method using 21 protein pairs extracted from the Protein Data Bank (PDB), or selected from the recent literature. Globally, we again find the homologous structures (alpha-helices and beta-strands) of these pair proteins. The introduction of neighbor residue hydrophobicity in the conventional dotplot improves the alignment of proteins with low sequence identity (< 25%). HNH, written in standard ANSI C with the graphic library X11, under UNIX, is available on request.

Cluster Analysis↗
PubMed1994

A method for quantitative image assessment based on redundant feature measurements and statistical reasoning.

Advances in computer graphics and electronics have contributed significantly to the increased utilization of digital imaging throughout the scientific community. Recently, as the volume of data being gathered for biomedical applications has begun to approach the human capacity for processing, emphasis has been placed on developing an automated approach to assist health scientists in assessing images. Methods that are currently used for analysis often lack sufficient sensitivity for discriminating among elements that exhibit subtle differences in feature measurements. In addition, most approaches are highly interactive. This paper presents an automated approach to segmentation and object recognition in which the spectral and spatial content of images is statistically exploited. Using this approach to assess noisy images resulted in correct classification of more than 97% of the pixels evaluated during segmentation and in recognition of geometric shapes irrespective of variations in size, orientation, and translation. The software was subsequently used to evaluate digitized stained blood smears.

Algorithms↗
PubMed1994

A SAS macro for residual deviance of ordinal regression analysis.

In this paper, a SAS macro is described for calculating the likelihood of the 'saturated' model in the analysis of ordinal regression. The outcome variable is multinomial on an ordinal scale, while the explanatory variables can be nominal or ordinal. Several ordinal regression models may be fitted to the data. One method of testing for the goodness of fit of these regression models is by comparing the residual deviance with the chi 2 distribution. In SAS, PROC LOGISTIC may be used to fit this type of data with proportional odds model. Unfortunately, the residual deviance is not available from the output. Our SAS macro will supplement the SAS output so that the residual deviance test may be carried out. The data from an ongoing HIV study is used as an illustration.

Bias↗
PubMed1995

The pragmatics of clinical hypermedia: experiences from 5 years of participatory design in the MEDEA project.

To explore a medical hypermedia design process where requirements engineering and participatory design are used in a naturalistic setting, 5 years of participatory action research (PAR) have been performed in the development of a hypermedia system to be used in primary care practice. In PAR, the participating organizations cooperate with the researchers in deciding and later evaluating organizational actions, and the results are concluded cooperatively. A new type of system emerged from the study, in that the resulting design has its focus on the management of large volumes of hypermedia material, the traceability of authority in the documents, and teamwork support. Regarding the participatory design process, it was found to be essential to deal with social and organizational issues in the design group and its surroundings--and not to cover these over. For instance, an agreement was reached with the managers responsible for health care in the county where the design process took place, whereby the design activity was also given priority at the highest local administrative level. Since health care is a practice organization, there is a potential market for similar systems if only ways of organizing design and marketing the products of participatory design are further developed. Modified versions of structured product specification methods could be a valuable complement. The conclusion of the study is that the development and spread of hypermedia systems in health care may require considerable changes in current design routines and organizations.

Administrative Personnel↗
PubMed1994

Structuring the patient record: NUCLEUS (customisation environment for multi-media integrated patient records).

The NUCLEUS project (AIM A2025) develops a prototype of a multi-media integrated patient record, based on the concepts of intelligent act management as conceived in RICHE (Esprit 2221). Moreover, NUCLEUS creates facilities for the customisation of such patient record according to the requirements of the health professionals (physicians, nurses, therapists, etc.) who operate and consult the patient record. Health professionals retain full control of the patient record contents:--NUCLEUS offers facilities to structure any significant patient record, subject to the specifications of the health professionals involved. Finally, NUCLEUS implements its results in the practical clinical conditions of the three leading European hospitals.

Europe↗
PubMed1994

ORATEL: telematic system for quality assurance in oral health care (AIM Project A2029).

ORATEL is a 3-year project with the ultimate objective of improving oral health through use of appropriate computerized information systems. These tools will promote quality assurance and development in oral health care by using common quality indicators/standards. The project has completed its first phase, during which two European surveys were made, one on quality assurance clinical practices, and another on existing computerized information systems in oral health care. Pan European consensus was reached on 3 and 4 September 1992 when quality assurance indicators for oral health care services were endorsed. A manual on quality assurance indicators in oral health care has also been issued by the project.

Computer Communication Networks↗
PubMed1994

SETH: an expert system for the management on acute drug poisoning in adults.

The aim of SETH is to give end-users specific advice concerning treatment and monitoring of adult drug poisoning. SETH is developed with an off the shelf expert system shell (KBMS) and runs on a microcomputer. Technical choices were done according to this analysis, financial considerations and portability. Currently, the database contains 1000 French drugs from 75 different toxicological classes. The SETH expert system simulates the expert reasoning, taking into account for each toxicological class delay, signs and dose. Two phases of evaluation were performed. The experimental implementation of Seth began in April 1992 in our Poison Control Centre. Since then, 1100 cases inputted by residents were analysed by SETH. The extension of the knowledge base to child poisoning began in March 1993.

Acute Disease↗
PubMed1994

Development of Design-a-Trial, a knowledge-based critiquing system for authors of clinical trial protocols.

Many published clinical trials are poorly designed, suggesting that the protocol was incomplete, disorganised or contained errors. This fact, doctors' limited statistical skills and the shortage of medical statisticians, prompted us to develop a knowledge-based aid, Design-a-Trial, for authors of clinical trial protocols. This interviews a physician, prompts them with suitable design options, comments on the statistical rigour and feasibility of their proposed design and generates a 6-page draft protocol document. This paper outlines the process used to develop Design-a-Trial, presents preliminary evaluation results, and discusses lessons we learned which may apply to the developed of other medical decision-aids.

Clinical Trials as Topic↗
PubMed1994

Safety-critical software and current standards initiatives.

This paper sets out to examine the role of standards in the development of safety-critical software. It starts with a brief discussion on the nature and role of standards and then moves on to identify some of the standards making bodies. Safety-critical software is next discussed and the problems of software safety are contrasted with those of traditional electromechanical devices. There then follows a review of some of the current initiatives to produce standards addressing the development of safety-critical systems containing software. Two standards are then examined in detail to provide an insight into what requirements are placed on the developers of safety-critical software. Lastly, mention is made of some weaknesses that are inherent in today's standards, and some of the efforts that are being made to address these problems are discussed.

Accidents, Occupational↗
PubMed1994

An overview of software assessment.

Many engineering systems, especially those required to be particularly dependable, traditionally undergo inspections and assessments of safeness and fitness for purpose. Often some form of 'certificate' is provided by the assessment authority. To an increasing degree these systems are beginning to contain software components. The question naturally arises: how can the software component be assessed? This paper explores the feasibility and limitations of software assessment and the link between the process of developing the software and the quality of the resulting software product.

Europe↗
PubMed1994

PACS for radiology conferences--improvement of application software.

The introduction of PACS in a radiology department means that most functions that are available in the film-based system must be included. One important function is the radiology conference. The handling and application programs of digital workstations are normally not developed for demonstrations of many images in a limited time. This paper describes a workstation with specially designed software for radiology conferences. The application is separated in preparation and presentation of the cases to be demonstrated. Very fast image handling is achieved during the conference because the function is based on the principle of prefetching of the selected images. The images are presented on a large screen with high resolution. The experiences of digital radiology conferences are good. However, reference films from previous examinations create extra work because they have to be shown on the conventional lightbox.

Computer Terminals↗
PubMed1994

Microcomputer programs for physiologically-based pharmacokinetic (PB-PK) modeling.

Physiologically-based pharmacokinetic (PB-PK) models are each defined as a set of mathematical equations offering a fairly comprehensive time course of a chemical's disposition in several pre-selected anatomical compartments. Each of these compartments has its characteristic blood flow, volume, tissue-blood partition coefficient, and metabolic or clearance rate constants that together are deemed responsible for a chemical's disposition in that region. Numerous investigators have used these models to predict tissue dose in the animal or human body in recent years. This simulation technique, if proven effective, will eventually reduce the large number of animals that are required in the costly classic, in vivo studies to be conducted for chemical disposition or metabolism. This communication offers 2 affordable micro-computer programs which can be used as a practical simulation tool in further exploring the application of PB-PK modeling in chemical risk assessment. These 2 programs are written especially for investigators who prefer to have some appreciation of the required computer simulation first before committing themselves to using more advanced, expensive simulation software packages that are commercially available.

Administration, Cutaneous↗
PubMed1995

Supercomputer algorithms for efficient linear octree encoding of three-dimensional brain images.

We designed and implemented algorithms for three-dimensional (3-D) reconstruction of brain images from serial sections using two important supercomputer architectures, vector and parallel. These architectures were represented by the Cray YMP and Connection Machine CM-2, respectively. The programs operated on linear octree representations of the brain data sets, and achieved 500-800 times acceleration when compared with a conventional laboratory workstation. As the need for higher resolution data sets increases, supercomputer algorithms may offer a means of performing 3-D reconstruction well above current experimental limits.

Algorithms↗
PubMed1995

A computer program for automatic measurement of respiratory mechanics in artificially ventilated patients.

A program for automatic and periodic determination of respiratory mechanics in artificially ventilated patients is described. Airway pressure and flow signals are obtained from the ventilator in the controlled ventilation mode with constant flow inflation and end-inspiratory pause. Periodically, the program records both signals for a given time and it delimits a ventilatory cycle and its components out of this record. Then, four mechanical parameters of the respiratory system are calculated: (1) Rinit, the resistance obtained with the end-inflation occlusion technique; (2) Ers, the elastance (inspiratory) calculated from the slope of the airway pressure profile during inflation; (3) tau, the expiratory time constant; (4) PEEP, the global positive end expiratory pressure. All parameter measurements have been evaluated in experimental conditions, and are in good agreement with reference values. The complete software includes the display of the signals and of the trends together with automatic disk file backups. An additional program allows one to display the trends again and to create table text files containing all the recorded data for further analysis. The system proved to work in ICU and anaesthesia patients with various ventilators.

Adult↗
PubMed1995

WENDEC: a deconvolution program for processing hormone time-series.

The estimation of the glandular secretory rate from time-series of hormone concentration in plasma can be formulated as a deconvolution problem. In particular, the paper addresses the analysis of frequently sampled data collected in order to study spontaneous pulsatile secretion. Standard deconvolution methods do not allow for the non-negativity constraint and the presence of high-frequency components in the secretory rate. In order to overcome the intrinsic ill-conditioning of the problem, the maximum entropy method is used to obtain a probabilistic representation of the prior knowledge concerning the unknown secretory signal, thus leading to a White Exponential Noise (WEN) model. The deconvolution problem is then posed within a Bayesian framework and solved by means of Maximum-A-Posteriori estimation. The program that implements the algorithm handles non-negativity constraints, provides confidence intervals, and is computationally and memory efficient.

Algorithms↗