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Results for “Data Collection”

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At least 109 records · Page 6Linked to original sources
PubMed1987

Automated data collection and processing for a cycle ergometer.

A system is described for collection and processing of data from a cycle ergometer. Cycle pedals, specially made to withstand the extremely high forces exerted during maximal power cycling, contain transducers to measure pedal angle relative to the crank and foot forces both perpendicular and parallel to the pedal surface. An additional transducer monitors crank position. Output signals are conditioned, amplified, digitized by a 12-bit analog-to-digital converter, fed into a computer at 100 Hz/channel, and mathematically smoothed to attenuate noise. For each sample interval, foot force components perpendicular and parallel to the crank arm are calculated. Power generated on each crank revolution is determined from transducer information. Computer graphics display pedaling parameters vs. crank angle in both rectangular and circular format. Data files containing variables descriptive of pedaling force curves are produced to enable computerized statistical analysis of cycling performance.

Computer Graphics↗
PubMed1992

Fully three-dimensional reconstruction from data collected on concentric cubes in Fourier space: implementation and a sample application to MRI.

An algorithm is proposed for rapid and accurate reconstruction from data collected in Fourier space at points arranged on a grid of concentric cubes. The Fourier transform of the object to be reconstructed is decomposed into the sum of three functions by subdividing its domain into three non-overlapping mutually orthogonal double pyramids. Each of the three functions is zero-valued outside one of the double pyramids and has values inside that double pyramid which are the same as those of Fourier transform of the object to be reconstructed at the same points. Inverse Fourier transforms of these individual functions can be calculated using the chirp z-transform. The outputs of these inverse transforms for the three functions are estimates of their values at points of the same rectangular grid. The function to be reconstructed is estimated for this grid by adding together the three inverse transforms. The whole process has computational complexity of the same order as required for the 3D fast Fourier transform and so (for medically relevant sizes of the data set) it is faster than backprojection into the same size rectangular grid. The design of the algorithm ensures that no interpolations are needed, in contrast to methods involving backprojection with their unavoidable interpolations. As an application, a 3D data collection method for MRI has been designed which directly samples the Fourier transform of the object to be reconstructed on concentric cubes as needed for the algorithm.

Algorithms↗
PubMed1976

Medical economics survey-methods study: design, data collection, and analytical plan.

This paper describes the background, methodology, data collection, and analytical plan of a pilot investigation conducted under contract for the National Center for Health Statistics during 1975. The objective was to determine the cost effectiveness of a variety of strategies under consideration for national application to develop previously unavailable information on utilization of, and the costs and payments for, health care. Detailed data on health care utilization and expenditures were collected periodically from a panel of 691 Maryland households over a six-month interval. Issues to be tested through a random experimental design include whether periodicity (monthly vs bimonthly interviews) and type of contact (in-person vs telephone) are significant factors in the cost effectiveness of this type of survey. An extensive record check involving all providers and third-party payers identified in the household survey was carried out. Record information will be used to 1) provide a basis for measuring accuracy of household data, 2) fill gaps in household knowledge, and 3) determine whether a subset of the record sources can provide adequate information for correcting household data. The household survey resulted in an initial response rate of 77.5 per cent with a subsequent attrition rate over six months of 13.6 per cent. Signed permission to access record data was obtained for 84.9 per cent of the individuals completing the entire survey. The most intensive survey strategy, monthly, mostly in-person contact, resulted in the lowest participation. The analytical plan presents details of the approaches to be taken in making judgments on the relative accuracy and completeness of data obtained by the various survey strategies and the contribution made by availability of data from record sources.

Adolescent↗
PubMedDate not supplied

Drugs of abuse: data collection systems of DEA and recent trends.

The U.S. Drug Enforcement Administration has several different systems for collecting information on drugs of abuse. One is an early warning system, which collects information to provide scientific data and interpretation on drug abuse. Another is the collection of data from evidence submitted to DEA laboratories. This is a review of the significance of the data in each system and an examination of some of the trends observed from the data.

Costs and Cost Analysis↗
PubMed1992

TCK: a clinical genetics data collection system.

This work examines the database design and user interface design for a clinical genetics data collection system known as TCK. A specific design goal is automatic generation of the CORN reports. Emphasis in this paper is on how the logical data model resulting from the database design, and the user interface work together to enforce the enterprise results pertaining to data. Data screens are shown, sample queries are explained and the data mapping to the CORN reports presented.

Computer Simulation↗
PubMed1979

Data collection for cross-sectional image reconstruction by a moving ring of positron annihilation detectors.

A ring of positron annihilation detectors capable of two independent motions in the plane of the ring is considered. It can rotate around its center, and the whole ring may move so that its center traces a circular path. Provided certain parameters are chosen according to given formulas, data collected by such a detector ring can be reorganized (rebinned), in a computationally very inexpensive fashion, so that the data items in each bin are measurements along parallel lines spaced at small equal intervals. Efficient high resolution reconstruction algorithms that assume such data organization can therefore be applied to data collected collected by a moving positron ring detector. The method is demonstrated on a realistic example.

Computers↗
PubMedDate not supplied

The weekly return as a practical instrument for data collection in office based research.

This report describes the advantages and limitations of one approach to concurrent data collection required for investigations of primary care in one or more practices even when those practices are separated by large distances. The weekly return provides useful data and is a practical means of data retrieval well-accepted by clinicians.

Ambulatory Care Information Systems↗
PubMed1988

An IBM-PC based data collection system for recording rodent sexual behavior and for general event recording.

A microcomputer (IBM-PC) based data collection system for the acquisition and analysis of male rodent copulatory behavior and its reflexive components has been developed. This software features ease of data entry, flexibility across experimental protocols, and built-in tutorials. The program for the recording and analysis of sexual reflexes of the male is readily adapted for recording other behavior patterns.

Animals↗
PubMed1994

Five viral peptide-HLA-A2 co-crystals. Simultaneous space group determination and X-ray data collection.

We prepared and crystallized five complexes of the human histocompatibility molecule HLA-A2 with peptides derived from human immunodeficiency virus type 1, human T lymphotropic virus type 1, influenza A virus and hepatitis B virus proteins. Each HLA-A2 complex was refolded in vitro from insoluble proteins produced in bacteria; to crystallize, two of the complexes required seeding with microcrystals of another complex. Maintained at -160 degrees C, single co-crystals of each of the five peptide-HLA-A2 complexes yielded complete X-ray diffraction data sets to a resolution of approximately 2.5 A. After a sufficient number of diffraction peaks were acquired during data collection, the direct analysis of integrated intensities established the point group of the co-crystal, thus allowing an efficient data collection strategy to be designed. The subsequent examination of systematic absences revealed that the five peptide-HLA-A2 co-crystals formed in space groups P1, P2(1), or P2(1)2(1)2(1). Molecular replacement structure solutions yielded unambiguous protein electron density maps, thus confirming the space group determinations. The system of obtaining HLA-A2 co-crystal structures described here is applicable to other crystallographic problems where structures of several related molecules from uncharacterized single crystals are required.

Amino Acid Sequence↗
PubMed1991

The Pregnancy Risk Assessment Monitoring System: design, questionnaire, data collection and response rates. PRAMS Working Group.

The birth certificate, the primary tool for population-based surveillance of the condition of infants at birth and maternal status during pregnancy, provides little data about maternal behaviour during pregnancy. To collect data on maternal behaviours that influence pregnancy outcome, we implemented the Pregnancy Risk Assessment Monitoring System in seven states. For this population-based surveillance, new mothers were sampled from birth certificates 2 to 6 months after delivery and contacted by mail; follow-up of nonrespondents was by telephone. Participants completed a 10-page questionnaire. Stratification permitted over-sampling of women with adverse pregnancy outcomes. Among 10,563 women sampled during 1988 and 1989, stratum-specific response rates ranged from 30% to 89%. In 11 of the 28 strata, response rates were greater than 70%. Response rates varied considerably between states. Rates were lower for Black mothers, mothers of low birthweight infants, unmarried mothers and mothers with less than 12 years of education. Active refusal to participate and undelivered mail occurred infrequently. Mail and telephone surveillance of new mothers can yield adequate response rates in selected population groups. Trials of alternative approaches to enhancing response among Black and disadvantaged mothers, such as additional mailings or post-partum in-hospital recruitment, are needed.

Black or African American↗
PubMed1975

Gamma-ray spectrometry data collection and reduction by simple computing systems.

The review summarizes the present state of the involvement of relatively small computing devices in the collection and processing of gamma-ray spectrum data. An economic and utilitarian point of view has been chosen with regard to data collection in order to arrive at practically valuable conclusions in terms of feasibility of possible configurations with respect to their eventual application. A unified point of view has been adopted with regard to data processing by developing an information theoretical approach on a more or less intuitive level in an attempt to remove the largest part of the virtual disparity between the several processing methods described in the literature. A synoptical introduction to the most important mathematical methods has been incorporated, together with a detailed theoretical description of the concept gamma-ray spectrum. In accordance with modern requirements, the discussions are mainly oriented towards high-resolution semiconductor detector-type spectra. The critical evaluation of the processing methods reviewed is done with respect to a set of predefined criteria. Smoothing, peak detection, peak intensity determination, overlapping peak resolving and detection and upper limits are discussed in great detail. A preferred spectrum analysis method combining powerful data reduction properties with extreme simplicity and speed of operation is suggested. The general discussion is heavily oriented towards activation analysis application, but other disciplines making use of gamma-ray spectrometry will find the material presented equally useful. Final conclusions are given pointing to future developments and shifting their centre of gravity towards improving the quality of the measurements rather than expanding the use of tedious and sophisticated mathematical techniques requiring the limits of available computational power.

Activation Analysis↗
PubMed1984

Use of a viewdata system to collect data from a multicentre clinical trial in anaesthesia.

The interactive electronic information storage and transmission system PRESTEL was assessed as a method of recording and collecting patient record forms from a multicentre trial in anaesthesia. PRESTEL terminals were provided in anaesthetic centres around Britain and all data handled by this public viewdata service, which connects users by telephone to a central computer. The trial was of a new analgesic supplement, alfentanil, and confirmed more rapid recovery of patients as compared with that after traditional anaesthesia with halothane. Advantages of the system were manifold and included reducing the need for the trial monitor to visit the trialist, an electronic "mailbox," confidentiality, and the ability immediately to identify violations of study protocol. No participant found the system too difficult to use, though the small keyboard was a source of complaint. Despite the initial cost of the system its utility vastly outweighs traditional methods of data collection.

Adjuvants, Anesthesia↗
PubMed1991

Reporting errors in time-to-pregnancy data collected with a short questionnaire. Impact on power and estimation of fecundability ratios.

Few tools exist in reproductive epidemiology for studying adverse effects on fertility. Data on time to pregnancy (the number of menstrual cycles required to conceive) can be used to estimate fecundability ratios, a sensitive endpoint for identifying factors associated with reduced fertility. Time-to-pregnancy data can be collected in detailed interviews. The accuracy of data collected on brief, self-administered questionnaires is not known. In a study of occupational exposures to dental assistants conducted in 1987-1988, 523 women provided time-to-pregnancy data both on a short, mailed questionnaire and in a detailed telephone interview. The correlation between the two measures was 0.82. Assuming that the detailed data were accurate, reporting errors in data from the short form were distributed nondifferentially with respect to most covariates of interest in fecundability analyses. Simulation studies were conducted to estimate bias and loss of power from the misclassification. Bias was toward the null. Substantial power was lost in detecting weak exposures. However, exposures that reduce fecundability by 50 percent (equivalent to adding about three cycles to the median time to pregnancy) could still be detected with 80 percent power in samples of about 100 women (half of them exposed to a possible toxin). The authors conclude that time-to-pregnancy data collected with a few self-administered questions can be useful in a variety of epidemiologic studies, including occupational and environmental surveillance programs.

Bias↗