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 1,315 records · Page 73Linked to original sources
PubMed2006

A comparison of gene expression in mouse liver and kidney in obstructive cholestasis utilizing high-density oligonucleotide microarray technology.

AIM: To assess the effects of obstructive cholestasis on a wider range of gene expression using microarray technology. METHODS: Male C57BL/6J mice underwent common bile duct ligation (BDL) and were matched with pair-fed sham-operated controls. After 7 d, the animals were sacrificed and total RNA was isolated from livers and kidneys. Equal amounts of RNA from each tissue were pooled for each group and hybridized to Affymetrix GeneChip MG-U74Av2 containing a total of 12488 probe sets. Data analysis was performed using GeneSpring 6.0 software. Northern analysis and immunofluorescence were used for validation. RESULTS: In sham-operated and BDL mice, 44 and 50% of 12488 genes were expressed in livers, whereas 49 and 51% were expressed in kidneys, respectively. Seven days after BDL, 265 liver and 112 kidney genes with GeneOntology annotation were up-regulated and 113 liver and 36 kidney genes were down-regulated in comparison with sham-operated controls. Many genes were commonly regulated in both tissues and metabolism-related genes represented the largest functional group. CONCLUSION: Following BDL, microarray analysis reveals a broad range of gene alterations in both liver and kidney.

25-Hydroxyvitamin D3 1-alpha-Hydroxylase↗
PubMed2005

Computer-assisted two-dimensional preoperative planning for total hip arthroplasty: clinical evaluation.

The purpose of this study is to clinically validate a new two-dimensional preoperative planning software for cementless total hip arthroplasty (THA). Manual and two-dimensional computer-assisted planning were compared by an independent observer for each of the 30 patients with osteoarthritis who underwent THA. This study showed that there were no statistical differences between the results of both preoperative plans in terms of stem size and neck length (<1 size) and hip rotation center position (<5 mm). Two-dimensional computer-assisted preoperative planning provided successful results comparable to those using the manual procedure, thereby allowing the surgeon to simulate various stem designs easily.

Arthroplasty, Replacement, Hip↗
PubMed1999

ROC analysis of three perfusion display options for ECG-gated perfusion SPECT in severe CAD.

AIM: The simultaneous computation and display of wall motion and perfusion patterns in a single 3D ventricular model would considerably ease the assessment of ECG-gated Tc-99m-sestamibi SPECT, yet the effect on the accuracy of allocating regional perfusion has so far not been validated. METHODS: 3D perfusion mapping (3D Perfusion/Motion Map Software) was compared to the visual assessment of ungated tomographic slices and polar perfusion mapping (Cedars-Sinai PTQ) by correlation analysis and receiver operating characteristics (ROC) analysis at different cut-off levels for coronary stenoses in 50 patients (11 single-, 22 two-, 16 three-vessel disease). Ungated SPECT data were obtained by adding the intervals prior to reconstruction and displaying conventional tomographic slices. All display options were visually assessed in 8 ventricular segments according to a 4-point scoring system and compared to the graded results of coronary angiography. RESULTS: All three display options showed a comparable diagnostic performance for the detection of severe stenoses. The diagnostic gain for the detection of stenoses above 59% was highest for ungated tomographic slices, followed by ungated polar mapping and 3D mapping. Regional assessment revealed a limited performance of 3D mapping in the proximal anterior and distal lateral wall. Polar mapping showed a balanced regional performance. CONCLUSION: 3D Perfusion mapping provides comparable information to conventional display options with the highest diagnostic strength in severe stenoses. Further improvement of the algorithm is needed in the definition of the valve plane.

Angina Pectoris↗
PubMed2002

Bayesian probabilistic network modeling of remifentanil and propofol interaction on wakeup time after closed-loop controlled anesthesia.

OBJECTIVE: Until now, the knowledge of combining anesthetics to obtain an adequate level of anesthesia and to economize wakeup time has been empirical and difficult to represent in quantitative models. Since there is no reason to expect that the effect of non-opioid and opioid anesthetics can be modeled in a simple linear manner, the use of a new computational approach with Bayesian belief network software is demonstrated. METHODS: A data set from a pharmacodynamic study was used where remifentanil was randomly given in three fixed target concentrations (2, 4, and 8 ng/ml) to 62 subjects. Target concentrations of propofol were controlled according to the closed-loop system feedback of the auditory evoked potential index to render modeling unbiased by the level of anesthesia. Time to open eyes was measured to represent wakeup time after surgery. The NETICA version 1.37 software was used on a personal computer for network building, validation, and prediction. RESULTS: After the learning phase, the network was used to generate a series of random cases whose probability distribution matches that of the compiled network. The sampling algorithms used are precise, so that the frequencies of the simulated cases will exactly approach the probabilities of the network and that of the data learned. The graphical display of the predicted wakeup time shows less variability but a more complex interaction pattern than with the unadjusted original data. CONCLUSIONS: Model building and evaluation with Bayesian networks does not depend on underlying linear relationships. Bayesian relationships represent true features of the represented data sample. Data may be sparse, uncertain, stochastic, or imprecise. Multiple platform software that is easy to use is increasingly available. Bayesian networks promise to be versatile tools for building valid, nonlinear, predictive instruments to further gain insight into the complex interaction of anesthetics.

Anesthesia Recovery Period↗
PubMedDate not supplied

[Multivalent informatics application for studies of the nutritional status of the population. Assessment of food intake].

The aim of the study is the presentation and validation of a computer program, GRUNUMUR, designed for nutritional evaluation studies in great population groups, and to describe some of the results obtained after the application of this working tool. This program includes he following types of studies: a) dietary study; b) food habits study; c) anthropometric study and d) clinical study. The main advantage of GRUNUMUR is the possibility of being periodically actualized without any important software knowledge, and to be opened to the introduction of new data bases. The software program GRUNUMUR Is one more of the multiple programs described in the literature. However, once validated, this tool has the particularity of being developed after an important experience in the nutritional field and only with a scientific purpose. The result is a reliable tool, which facilitates nutrition research.

Adolescent↗
PubMedDate not supplied

Highly effective techniques in computerized dental tissue morphometry.

The effectiveness of computer-aided morphometry is greatly dependent on the capabilities of the software platforms, but the literature provides only information about the measurement methods and their medical interpretation. The purpose of our work is to create a link between the technical algorithm and the medical significance, by a detailed description of measurement procedures, accompanied by the interpretation of their results. The developed techniques operate at a pixel level, by deriving a full benefit from the computational resources available in the modern software environments for image processing. The approach is built on three illustrative cases, formulated in a large sense, so as to cover classes of general problems, referring to cellular entities and tubular structures in cross and longitudinal section. Specimens belonging to the dentin-pulp complex were chosen, because they permit a quantitative analysis for each morphological element, as well as comparative discussion. With appropriate adaptations of the procedures, the measurements of other types of normal and pathological tissues can be analogously addressed. The design, implementation and exploitation of our procedures are supported by specific references to the use of an image analysis system (Zeiss KS400). The algorithmic background remains valid (except for some possible minor changes) when similar software is used. Consequently, the results and their interpretations, prove the importance of the numerical analysis in automating the quantitative evaluation of the structural features.

Algorithms↗
PubMed1993

Computer simulation in sport and industry.

The last several decades have brought decreases in the specific cost of computer memory and increases in processor throughput. As a result simulation has become correspondingly more important as a component of industrial design and as a method for the study of general biomechanics and sports techniques. This paper illustrates, by way of examples, several of the more important aspects of the application of computer simulation to dynamic problems. Topics include (1) the ideas of suitable model complexity and its tradeoff with interpretability; (2) the sequential and iterative nature of model building and the importance of experimental data in the modelling and validation process; (3) the essential role of user-friendly software and graphical interfaces in the interchange of information between simulation programs and the users; and 4) the role of computer simulation in learning feedback loops, both in the field and in the computer laboratory. Most industrial use of simulation is in the design process. A similar approach is equally valid in biomechanics and sport applications through the incorporation of design variables, which may be easily changed in the model experiment.

Biomechanical Phenomena↗
PubMed2004

[The value of hospital data bases in the quality of patient care].

Massive gathering of clinical records started quite soon, at the turn of the last century, about 100 years ago. In that period keeping and gathering of medical records gradually evolved from paper medical records to computer-based medical records. Software that we use for this is quite different. We are witnessing tendency that each medical institution is creating software solely for their use, that leads to difference of gathered medical data and their validity for further analysis. In this paper we tested value of gathering and processing medical records through a hospital software, regarding time consumption in everyday work, as well as value of gathered and processed data. Statistically significant difference was found in terms of time needed for complete gathering and processing of medical data of hospitalized patients, as well as most of its segments (administering of admission, forming a medical history, forming a discharge letter). No statistically significant differences were found in terms of value of gathered and processed data in the forms of electronical records, compared to those formed on "traditional" basis. We conclude that the future of gathering, forming and processing of medical documentation of hospitalized patients is solely through interactive computer databases, and that their everyday spreading through all systems and levels of health care is absolutely necessary. Only that way we shall be able to fully use possibilities that such interactive system offers in improving management of patients.

Databases as Topic↗
PubMed2001

COMKAT: compartment model kinetic analysis tool.

UNLABELLED: Compartment models are the basis for most physiologically based quantification of nuclear medicine data. Although some software packages are available for this purpose, many are expensive, run on relatively few types of computers or are of limited capability, and cannot be extended because of the unavailability of source code. Consequently, institutions with modeling expertise often develop software for themselves, which has the disadvantages of lack of standardization and possible replication of effort. Therefore, general-purpose compartment-modeling software distributed with source code would be a welcome resource for the nuclear medicine community. METHODS: We formulated a mathematic framework within which compartment models containing unimolecular and bimolecular (receptor saturation) kinetics can be described. We implemented this framework within MATLAB and call the resultant software COMKAT (Compartment Model Kinetic Analysis Tool). RESULTS: COMKAT simplifies the process of defining and solving standard blood flow, 18F-FDG, and receptor models as well as models of a user's own design. In particular, COMKAT automatically defines and implements state, analytic sensitivity, and Jacobian equations. Given these, COMKAT can perform simulations in which model outputs are solved for specified parameter values, thereby allowing the user to predict how sensitive data are to these parameters. In addition, COMKAT can be used to estimate values for the parameters by fitting model output to experimental data. COMKAT is equipped with command-line and graphic user interfaces from which the user can access these features. Examples of these applications are presented along with validation and performance summaries. CONCLUSION: COMKAT is a useful software tool and is available without cost to researchers, at www.nuclear.uhrad.com/comkat.

Computer Simulation↗
PubMed2006

Computational Methods for analysis of foci: validation for radiation-induced gamma-H2AX foci in human cells.

Observation and counting of gamma-H2AX foci in untreated cells as well as in cells exposed to cytotoxic agents is a widely used method for documenting the presence of double-strand breaks (DSBs) in the DNA and for analysis of their repair. Similar methods are employed to analyze formation of foci by a variety of proteins implicated in the cellular responses to DNA damage. Despite the wide application of the approach, the manual counting that is frequently used is prone to inaccuracies and investigator-related biases and artifacts. To alleviate this limitation, we developed and describe here personal computer-based algorithms, operating as utilities on available software, that allow an objective and quantitative analysis of foci from confocal images. The algorithms allow focus counting as well as size definition and correct for focus coincidence due to the overlap normally occurring with an increasing number of foci per nucleus. Furthermore, the software allows measurement of the integrated optical density (IOD) of each individual focus, which enables analysis of properties of foci as a function of time. Finally, the information generated by the above analysis algorithms can be employed to evaluate colocalization between foci formed by different proteins. A validation of the software is presented for radiation-induced gamma-H2AX foci in three widely used human cell lines and colocalization tested with RAD51 and gamma-H2AX foci. The computational methods presented extend to images generated by digital cameras.

Artificial Intelligence↗
PubMed2000

Field-by-field evaluation of intraoperative transoesophageal echocardiography interpretative skills.

A quality assurance system is essential for the credibility and structured growth of anaesthesiology-based transoesophageal echocardiography (TEE) programmes. We have developed software (Q/A Kappa), involving a 400-line source code, capable of directly reporting kappa correlation coefficient values, using external reviewer interpretations as the 'gold standard', and thereby allowing systematic assessment of the validity of intraoperative echocardiographic interpretation. This paper presents assessment of the validity of 240 intraoperative anaesthesiologists' echocardiographic interpretations, and, in addition, the results of field testing of this prototypical software. Data, derived from consecutive cardiac surgery patients, consisted of standardized two-dimensional transoesophageal echocardiographic, colour flow and Doppler imaging sequences. Intraoperative and off-line 'gold standard' TEE interpretations were compared for 19 fields or variables using the Q/A Kappa program. The kappa correlation coefficients were highly variable and dependent on the examination field, ranging from 0.08 for apical regional wall motion scores to 1.00 for tricuspid regurgitation grade, left atrial measurement, aortic valve anatomy and left ventricular long axis and short axis global function. The correlation coefficients were also operator dependent. These data (480 interpretations) were also manually integrated into the equation required for calculation of values of the variable kappa correlation coefficient. The relationship between Q/A Kappa-derived values and manually calculated values was highly significant (p < 0.001; r = 1.0). The implications and possible explanations of the results for particular examination fields are discussed. This study also demonstrates successful seamless functioning of this software program from data entry, segmentation into tables and valid statistical analysis. These findings suggest that it is practical to provide sophisticated continuous quality improvement TEE data on a routine basis.

Adult↗
PubMed2003

Probabilistic modelling of human exposure to intense sweeteners in Italian teenagers: validation and sensitivity analysis of a probabilistic model including indicators of market share and brand loyalty.

For the assessment of exposure to food-borne chemicals, the most commonly used methods in the European Union follow a deterministic approach based on conservative assumptions. Over the past few years, to get a more realistic view of exposure to food chemicals, risk managers are getting more interested in the probabilistic approach. Within the EU-funded 'Monte Carlo' project, a stochastic model of exposure to chemical substances from the diet and a computer software program were developed. The aim of this paper was to validate the model with respect to the intake of saccharin from table-top sweeteners and cyclamate from soft drinks by Italian teenagers with the use of the software and to evaluate the impact of the inclusion/exclusion of indicators on market share and brand loyalty through a sensitivity analysis. Data on food consumption and the concentration of sweeteners were collected. A food frequency questionnaire aimed at identifying females who were high consumers of sugar-free soft drinks and/or of table top sweeteners was filled in by 3982 teenagers living in the District of Rome. Moreover, 362 subjects participated in a detailed food survey by recording, at brand level, all foods and beverages ingested over 12 days. Producers were asked to provide the intense sweeteners' concentration of sugar-free products. Results showed that consumer behaviour with respect to brands has an impact on exposure assessments. Only probabilistic models that took into account indicators of market share and brand loyalty met the validation criteria.

Adolescent↗
PubMed1997

The actigraph data analysis software: I. A novel approach to scoring and interpreting sleep-wake activity.

Decades of empirical observations have established the validity of actigraphy primarily in individuals without sleep disorders. Methodological problems encountered thus far coupled with the widespread use of actigraphy signal the need for concentrated efforts to establish a consensus regarding scoring procedures. Currently available scoring methods show less reliability in clinical populations. To address these issues two validation studies were conducted: one for individuals without sleep disorders and the other for patients diagnosed with insomnia. The results of these two studies using the Actigraph Data Analysis Software as the scoring method have shown that the described system is fairly precise. It can be used for actigraphs with different features and mode of operation and is applicable to individuals with insomnia. These findings corroborate previous research showing that actigraphy is a valid instrument for assessment of sleep and wakefulness.

Calibration↗
PubMedDate not supplied

[An explanatory model of behavior toward mental illness].

OBJECTIVE: To evaluate a theoretical model designed to explain behaviors toward mental illness, considering some variables related to the construct. MATERIAL AND METHODS: A survey was conducted in 1996 on mental disorder beliefs, attitudes, and behavioral intentions. The sample population was stratified by socioeconomic status, age, and gender. Study subjects were 800 individuals from Mexico City's general population. A data collection instrument was constructed and validated, consisting of 120 Likert-type items with five options each. Data were coded and analyzed with the software package SPSS. Internal consistency of the scales was assessed using Cronbach's alpha and construct validity with factorial analysis. Student's t test and ANOVA were used to compare the groups in the different strata. RESULTS: The model allowed to confirm the predictive capacity of the causal chain connecting beliefs, attitudes, and intentions; nevertheless, other study variables did not contribute to explain it, and behavior was scarcely influenced by intentions, depending mainly on experimented necessity. CONCLUSIONS: Study findings constitute a basis to understand the attitudes of shame and fear usually related to mental illnesses, to plan efficient actions aimed at modifying them, and to design programs to promote mental health. The English version of this paper is available at: http://www.insp.mx/salud/index.html.

Adult↗
PubMedDate not supplied

Assistive technology to improve PC interaction for people with intention tremor.

Many patients with upper limb intention tremor encounter difficulties in mouse-driven interaction with the personal computer (PC). An assistive technology system ("the Tremor Control System"), consisting of a motion-filtering software program that supports multiple interfaces, was developed and validated with 36 persons with Multiple Sclerosis in a multi-center trial. PC-tests, requiring basic functions such as cursor placement and click and drag function, were able to differentiate between patients and control subjects (ANOVA: p<0.05). A significant time improvement on the PC-tests was found when using an optimal alternative interface instead of the standard PC-mouse (paired t-tests: p<0.01 for Point & Click test, p<0.05 for Drag & Drop test and p<0.1 for Double Click test). A significant time improvement was found for the Double Click test (paired t-tests: p<0.05) when the motion-filtering program was implemented. The number of patients able to perform fully the PC-tests increased with the Tremor Control System. Patients with marked intention tremor seemed to profit especially from this assistive technology. These users reported that working with the Tremor Control System was less fatiguing and more comfortable compared to the use of the standard PC-mouse.

Computers↗
PubMed2005

Serum protein fingerprinting coupled with artificial neural network distinguishes glioma from healthy population or brain benign tumor.

To screen and evaluate protein biomarkers for the detection of gliomas (Astrocytoma grade I-IV) from healthy individuals and gliomas from brain benign tumors by using surface enhanced laser desorption/ionization time of flight mass spectrometry (SELDI-TOF-MS) coupled with an artificial neural network (ANN) algorithm. SELDI-TOF-MS protein fingerprinting of serum from 105 brain tumor patients and healthy individuals, included 28 patients with glioma (Astrocytoma I-IV), 37 patients with brain benign tumor, and 40 age-matched healthy individuals. Two thirds of the total samples of every compared pair as training set were used to set up discriminating patterns, and one third of total samples of every compared pair as test set were used to cross-validate; simultaneously, discriminate-cluster analysis derived SPSS 10.0 software was used to compare Astrocytoma grade I-II with grade III-IV ones. An accuracy of 95.7%, sensitivity of 88.9%, specificity of 100%, positive predictive value of 90% and negative predictive value of 100% were obtained in a blinded test set comparing gliomas patients with healthy individuals; an accuracy of 86.4%, sensitivity of 88.9%, specificity of 84.6%, positive predictive value of 90% and negative predictive value of 85.7% were obtained when patient's gliomas was compared with benign brain tumor. Total accuracy of 85.7%, accuracy of grade I-II Astrocytoma was 86.7%, accuracy of III-IV Astrocytoma was 84.6% were obtained when grade I-II Astrocytoma was compared with grade III-IV ones (discriminant analysis). SELDI-TOF-MS combined with bioinformatics tools, could greatly facilitate the discovery of better biomarkers. The high sensitivity and specificity achieved by the use of selected biomarkers showed great potential application for the discrimination of gliomas patients from healthy individuals and gliomas from brain benign tumors.

Adult↗
PubMed1996

[Selection criteria for dental software].

Dentists who wish to introduce a computer based patient record system in their office are confronted with a lack of information concerning the selection of dental software. As wishes and demands concerning the content and options given by a dental computer program can vary widely from dentist to dentist and as dental software is changing rapidly a global objective evaluation is of no practical validity. Therefore a list of general and specific selection criteria was developed, enabling the practitioner to make a personal, objective comparison of quality of content versus wishes, price and service of different dental software programs. The criteria are discussed in this article.

Computer Peripherals↗
PubMed2003

The C.A.Ve. software tool for genome assembly.

Misassembly due to the presence of repetitive DNA sequences often complicates the contig assembly stage of genome sequencing. Accurate physical representations of chromosomes, such as restriction maps or contig maps, provide a means for validating the sequence assembly and clarifying alignment ambiguity. The Contig Assembly Verifier (CAVe) software tool allows the researcher to automatically reconcile a sequence assembly with a physical representation, and, if needed, to modify the assembly using an intuitive graphical user interface.

Algorithms↗