PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Software Validation”

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 361 records · Page 20Linked to original sources

Three-dimensional analysis of pulmonary nodules by MSCT with Advanced Lung Analysis (ALA1) software.

PURPOSE: The purpose of this study was to test the reproducibility of the three-dimensional (3D) Advanced Lung Analysis software (3D-ALA, GE Healthcare) in the estimation of pulmonary nodule volume. MATERIALS AND METHODS: We retrospectively reviewed the unenhanced multislice CT scans (Lightspeed Pro 16 GE) of 77 patients with a solitary pulmonary nodule (n=71) or metastatic pulmonary disease (n=6). A total of 103 pulmonary nodules (19 well-circumscribed, 45 juxtavascular and 39 juxtapleural) were analysed grouped into five classes based on diameter: <5 mm, 10 nodules (9.7%); >or=5 to <10 mm, 25 nodules (24.2%); >or=10 mm to <15 mm, 41 nodules (39.8%); >or=5 to <18 mm, 14 nodules (13.6% ); >or=8 to <30 mm, 13 nodules (12.62%). The following acquisition parameters were used: slice thickness 0.625 mm, reconstruction interval 0.4 mm, pitch 0.562:1, 140 kV, 300 mAs, field of view 13 cm, bone kernel. For each of the 103 nodules three, 3D volume measurements were obtained by the 3D-ALA software. The reproducibility of nodule segmentation was evaluated according to a visual score (1=optimal, >or=95%; 2=fair, 90-95%; 3=poor, 0.05). CONCLUSIONS: Three-dimensional volume measurement with ALARiassunto 1 software is reproducible for all nodules as regards dimension and site. ALA-1 software provided a good and reproducible volume measurement in well-circumscribed and most juxtavascular nodules. Volumetric evaluation and reproducibility of volume estimation in juxtapleural pulmonary nodules, particularly those adjacent to diaphragmatic pleura, is inadequate, and software improvement is needed.

Aged↗

An expert system on the diagnosis of ascites.

We constructed an expert system on the diagnosis of ascites, using a combination of case reports and unpublished patient data. Rule production was by induction from examples, and the program operated on an algorithm which was a modification of Quinlan's ID3. The result was a small, but formally complete expert system. When tested against a new data set of patients, our expert system predicted the clinical diagnosis 82% of the time.

Ascites↗

(PLOT79): a comprehensive portable Fortran scientific line graphics system, as applied to biomedical research.

Scientific results are often most succinctly presented in graphical form. We describe a system for computer-generated scientific line graphics known as (PLOT79), named to commemorate the SIGGRAPH CORE graphics standard proposal of 1979. (PLOT79) is a widely used and actively evolving graphics system, written primarily in SFTRAN3, a structured procedural computer language which can be translated readily into Fortran. The package embodies concepts of sound software engineering, having been designed from the outset to be portable, maintainable and hardware-independent; much of the effort required to implement the system was directed toward the development of software engineering tools to ensure these goals. A modular design strategy has allowed a wide variety of graphics output devices to be supported. (PLOT79) has been installed under numerous operating systems, and software tools provided by UNIX have allowed particularly efficient installation and use of the system. Access to (PLOT79) is available through three avenues: (1) linking (PLOT79) routines with a user-written high-level program; (2) use of pre-written high-level applications programs which perform certain frequently-required tasks such as the plotting of simple two or three-dimensional data; or (3) the use of an interactive graphics command parser known as slides. (PLOT79) has proven popular among workers in the physical sciences and engineering both for its easy availability, openness (all source code is provided), and powerful capability. The system presents an equally important (though lesser known) resource for biomedical research, as demonstrated by examples from ongoing biomedical research projects. It also provides a focus for discussion of the practical limitations inherent in existing graphics standards and programming languages.

Computer Graphics↗

A PC program for growth prediction in the context of Rao's polynomial growth curve model.

We consider the problem of growth prediction in the context of Rao's [1] one-sample polynomial growth curve model and provide a PC program, written in GAUSS, to perform the associated computations. Specifically, the problem considered is that of estimating the value of the measurement under consideration for a "new" individual at the Tth time point given measurements on that individual at T-1 previous points in time and the values of the measurement on N "similar" individuals at all T time points. The times of measurement t1, t2, . . ., tT need not be equally spaced, but we assume that each of the N individuals comprising the normative sample were measured at these times. The method and the program are illustrated using the leave-one-out method on a sample of N = 12 male rhesus monkeys whose mandibular ramus height was measured five times at yearly intervals.

Animals↗

Nonparametric estimation of potency ratio for dilution assays.

The paper considers the estimation of the potency of an unknown test preparation in relation to a standard in a dilution assay. The method utilizes the Mantel-Haenszel one degree of freedom chi-square approach to test consistency of the observed potency ratio with a range of alternative potency ratios. The method is nonparametric as it does not require any distributional assumptions. However, it requires the doses employed to be equally spaced logarithmically. The dose-response curve is also required to be monotone over the dose range used.

Biological Assay↗

A hardware-independent data acquisition package incorporating a simulation driver and simulation description language.

Device drivers for commercial data acquisition boards (DASH-16, DT2801) and a device driver for a virtual data acquisition board have been developed and incorporated in a single package for a multiple station anesthesia research laboratory. The package provides a compiler for a simulation description language which is used to program the virtual board. The package, written in C for the IBM PC, was designed to be easily extended with additional drivers. Applications using the package can control all supported devices without the programmer having to learn the details of the hardware.

Computer Simulation↗

A PC program for unbiased and predictive linear and quadratic discriminant analysis.

Discriminant analysis plays an important role in biological and medical research. The most popular methods of discrimination in practical applications are parametric methods like linear and quadratic discriminant analysis. However, there exist modifications of these approaches, namely unbiased and predictive discriminant analysis, which lead to reduced error rates in certain situations. In this paper a menu-driven, user-friendly PC program written in Borland Pascal 7.0 is introduced which performs unbiased and predictive linear and quadratic discriminant analysis.

Bias↗

Dynamic circular buffering: a technique for equilibrium gated blood pool imaging.

We have devised a software technique called "dynamic circular buffering" (DCB) with which we create a gated blood pool image sequence of the heart in real time using the best features of LIST and FRAME mode methods of acquisition/processing. The routine is based on the concept of independent "agents" acting on the timing and position data continuously written into the DCB. This approach allows efficient asynchronous operation on PC-type machines and enhanced capability on systems capable of true multiprocessing and multithreading.

Gated Blood-Pool Imaging↗

EndoCyte, an interactive computer program for quantitative analysis of receptor-mediated endocytosis.

We present EndoCyte, a user friendly interactive program for quantitative analysis of receptor-mediated endocytosis. The data, comprised of time-dependent concentrations of the ligand at the cell surface and the ligand internalized by cells, are analyzed by the application of a set of nested mathematical models of endocytosis. EndoCyte reduces data to parameters conventional in description of receptor-mediated endocytosis and a parameter which describes the non-linear effects. The performance of EndoCyte is documented by the analysis of applications to synthetic data.

Computer Simulation↗

The LBI-method for automated indexing of diagnoses by using SNOMED. Part 2. Evaluation.

We present a simple, formal, lexicon-based method for automated indexing of diagnoses based on the Systematized Nomenclature of Medicine (SNOMED), called LBI-method. Part 1 gave an introduction to the LBI-method and presented its realisation as application system SALBIDH. Part 2 presents the design and the results of an evaluation study to judge the quality of the LBI-method. In this evaluation study the quality of automated indexing as well as the quality of the retrieval of patient data by using automated indexed diagnoses was examined. The results show that the retrieval based on SNOMED indices is at least as good as the retrieval based on ICD classes despite a lot of indexing errors. From this we gather that our system is not yet good enough for immediate routine use but that an appropriate indexing quality and, as a result, a higher retrieval quality can be achieved after few improvements of the LBI-method, especially after revision of the lexicons.

Abstracting and Indexing↗

Clinical workstations: identifying clinical requirements and understanding clinical information.

A preliminary exploration of the problem of defining and meeting users' needs, this paper draws the bulk of its content from experiences in the PEN&PAD project in the UK. This program has been researching and developing prototype clinical workstations for direct use in patient care by health care professionals, chiefly doctors. Focusing more on general issues rather than the specific functional requirements embodied in the PEN&PAD prototypes, the paper begins with a brief summary of the goals of PEN&PAD and then outlines the three main axes of the work: user-centred design, medical concept and medical record models, and user interfaces and architectures. The remainder of the paper then concentrates on the first of these topics--working with users to define functional requirements.

Computer Systems↗

Major issues in user interface design for health professional workstations: summary and recommendations.

Lack of good user interfaces has been a major impediment to the acceptance and routine use of health-care professional workstations. Health-care providers, and the environment in which they practice, place strenuous demands on the interface. User interfaces must be designed with greater consideration of the requirements, cognitive capabilities, and limitations of the end-user. The challenge of gaining better acceptance and achieving widespread use of clinical information systems will be accentuated as the variety and complexity of multi-media presentation increases. Better understanding of issues related to cognitive processes involved in human-computer interactions is needed in order to design interfaces that are more intuitive and more acceptable to health-care professionals. Critical areas which deserve immediate attention include: improvement of pen-based technology, development of knowledge-based techniques that support contextual presentation, and development of new strategies and metrics to evaluate user interfaces. Only with deliberate attention to the user interface, can we improve the ways in which information technology contributes to the efficiency and effectiveness of health-care providers.

Cognition↗

Automated metrics for user interface design and evaluation.

Automated metrics will allow user interfaces to be partially evaluated early in the development process. They allow potential problems to be identified and corrected prior to user testing, saving both time and money. As a result, improved interfaces can be developed without additional costs. Both task-independent and task-sensitive automated metrics appear promising. Task-independent metrics should prove most useful for predicting user preferences and somewhat useful for predicting user performance. Task-sensitive metrics should prove useful for predicting both user preferences and performance. Several metrics are introduced and research directions are discussed.

Computer Systems↗

New opportunities for processing the OSI-7 layer protocols using parallel processing (transputers).

The attractiveness of the OSI-7 layer model is closely dependent upon a highly ambitious intent to promote a series of quasi-universal standards to coordinate the communication between heterogeneous applications, whatever the distributed architectures might be. However, a major criticism of the OSI-model is the performance and the handling of the presentation layer. This paper deals with the evaluation of parallel processing techniques operating at the upper levels of the OSI-model using transputers in a parallel co-processor. It is shown that the performance problem is highly dependent on the structure of the protocol stack and its implementation. With the object-oriented modularization of the protocol stack, an architecture of a possible co-processor using transputers is considered and its performance is considered adequate. An ideal configuration is briefly presented. A final performance appraisal of the parallelism effect is discussed with some insight into the future.

Computer Communication Networks↗

A Dutch medical language processor.

This paper describes the current state of a medical language processor for Dutch. The goal is to implement a language specific front-end compatible with some existing applications that aim at the intelligent extraction and processing of information from patient discharge summaries. A complete chain for processing and understanding Dutch medical documents will be the ultimate result. The text focuses mainly on the language specific aspects of the language processing chain. Evaluation results of the already functioning components are given as well as an outline for future developments and enhancements. A short theoretical background is provided (cf. also [1-3]: Rossi Mori et al., Proc. SCAMC 90, 1990, pp. 185-189; Wingert, in: Informatics and Medicine, an advanced course, Springer-Verlag. 1977, pp. 579-646; Wingert, Proc. MEDINFO 80, 1980, pp. 1321-1331) before the description of each component in order to familiarise the non-experienced reader with the basic notions of computational linguistics.

Artificial Intelligence↗

Relationship of vascular thrombosis and inflammatory leukocyte infiltration to neointimal growth following porcine coronary artery stent placement.

BACKGROUND: Superficial and intramural thrombosis are reproducible histopathological features of the porcine coronary oversized stent injury model. Fibrin and its degradation products are chemotactic for mononuclear leukocytes, and promote the proliferation and migration of vascular smooth muscle cells (VSMC) in vitro. The goal of this study was to quantitate the serial histomorphologic evolution of thrombosis, leukocyte infiltration, VSMC proliferation and collagen accumulation following porcine coronary artery stent placement in a porcine model. METHODS: Twenty-four normocholesterolemic swine underwent oversized balloon (3.5-4.0 mm) coronary angioplasty and tantalum metal stent placement. Twenty-six different arterial sites were injured, followed by serial sacrifice at day 4 (n = 6), 8 (n = 6), 14 (n = 6), and 28 (n = 6). Quantitative analysis of the neointima was performed using a high resolution video-microscopy interface and a validated histomorphometric software program. Alpha actin-positive VSMC density (per 10(4) micro(2) neointimal area) and collagen-specific picro-sirius red fluorescence (percent of neointima) were quantitated at sites adjacent to and distant from coronary artery stent placement. RESULTS: The percent of total neointimal area occupied by resolving thrombus material was greater at days 4-8 compared to 14-28 days (59-63% vs. 1-2%; P = 0.001). Mononuclear leukocytes were also significantly increased at days 4 and 8 (92 +/- 1 and 70 +/- 8%) compared to days 14-28 (both 3 +/- 3%; P = 0.001), as a percentage of the total neointimal cellularity. Total neointimal cell density did not change (20 +/- 10, 12 +/- 6, 23 +/- 7 and 20 +/- 3 cells/10(4) micro(2); P-value, NS), despite progressive cross-sectional vascular area stenosis reduction from 7 +/- 3% at day 4 to 72 +/- 14% at day 28 (P = 0.001). Percent neointimal fibrinoid thrombus content and mononuclear leukocyte cellularity were correlated in this model (R = 0.81; P < 0.001). Peri-stent neointimal collagen staining exceeded that at vascular sites distant from porcine coronary stent placement by 14 days (29 +/- 6 vs. 15 +/- 3%), and remained greater at 28 days (35 +/- 11 vs. 16 +/- 12%) (both P < 0.05). CONCLUSIONS: Quantitative serial histomorphometry of porcine coronary vascular stent delivery sites demonstrates early (4-8 day) neointimal mononuclear leukocyte infiltration which is histomorphologically and temporally related to intramural fibrinoid thrombosis. Significant vascular stenosis and collagen deposition occurs by 14-28 days at these vascular injury sites. These data suggest a local interaction between thrombotic and inflammatory elements in porcine coronary neointima following oversized stent injury.

Angioplasty, Balloon↗

Impact on the management and delivery of primary health care by a computer-based information system.

Timely and accurate information forms the basis for management to plan and for care providers to take appropriate action. We report from a developing country a research project aimed to strengthen the information infrastructure with a computer at a Primary Health Centre. The software (MCHS) was designed to assist the care providers in the information management for the Maternal and Child Health (MCH) programme activities. In Phase I, a baseline survey was conducted to identify the needs and target groups. In Phase II, the MCHS was integrated into routine delivery of MCH to monitor the target population and help in evaluation. The research project's impact is reflected in enhanced utilization of services and quality in care, as seen by reduction of dropouts from the immunization program. In economic terms, we see that the costs for a fully immunised child are reduced with reduction of dropouts; thus, the computer system contributes to quality assurance and cost effectiveness in delivery of care.

Adolescent↗