flow study

Also found in: Dictionary, Thesaurus, Encyclopedia.


a careful examination of a phenomenon; see also design.
cohort study prospective study.
cross-sectional study one employing a single point of data collection for each participant or system being studied. It is used for examining phenomena expected to remain static through the period of interest. It contrasts with a longitudinal s.
electrophysiological s's (EPS) studies from within the heart of its electrical activation and response to electrical stimuli and certain drugs. In general they include intravenous and/or intra-arterial placement of one or more electrode catheters at sites in the atria, ventricles, or coronary sinus, and sometimes the pulmonary artery or aorta. They record activity or stimulate the heart at various rates and cadences and are aids in the evaluation of electrophysiologic properties such as automaticity, conduction, and refractoriness. They also initiate and terminate tachycardias, map the sequence of activation, and aid in evaluation of patients for various forms of therapy and for the response to therapy. During these studies catheter ablation procedures, such as radio frequency ablation and electrical ablation, may be performed.
flow study uroflowmetry.
longitudinal study one in which participants, processes, or systems are studied over time, with data being collected at multiple intervals. The two main types are prospective studies and retrospective studies. It contrasts with a cross-sectional s.
pilot study a smaller version of a proposed research study, conducted to refine the methodology of the later one. It should be as similar to the proposed study as possible, using similar subjects, the same setting, and the same techniques of data collection and analysis.
prospective study an epidemiologic study in which the groups of individuals (cohorts) are selected on the bases of factors that are to be examined for possible effects on some outcome. For example, the effect of exposure to a specific risk factor on the eventual development of a particular disease can be studied. The cohorts are then followed over a period of time to determine the incidence rates of the outcomes being studied as they relate to the original factors in question. Called also cohort study.

The term prospective usually implies a cohort selected in the present and followed into the future, but this method can also be applied to existing longitudinal historical data, such as insurance or medical records. A cohort is identified and classified as to exposure to the risk factor at some date in the past and followed up to the present to determine incidence rates. This is called a historical prospective study, prospective study of past data, or retrospective cohort study.
retrospective study an epidemiologic study in which participating individuals are classified as either having some outcome (cases) or lacking it (controls); the outcome may be a specific disease, and the persons' histories are examined for specific factors that might be associated with that outcome. Cases and controls are often matched with respect to certain demographic or other variables but need not be. As compared to prospective studies, retrospective studies suffer from drawbacks: certain important statistics cannot be measured, and large biases may be introduced both in the selection of controls and in the recall of past exposure to risk factors. The advantage of the retrospective study is its small scale, usually short time for completion, and its applicability to rare diseases, which would require study of very large cohorts in prospective studies. See also prospective s.
urinary flow study uroflowmetry.
voiding pressure study simultaneous measurement of bladder contraction, urinary flow, and sphincter electromyogram.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.
References in periodicals archive ?
Based on this knowledge, the nurse performed a repeat access blood flow study on the next treatment.
* Acontractile detrusor: Absence of contraction during pressure flow study.
The cases enrolled in the study after this period underwent routinely the Pressure Flow study using the Delphi's TM Laborie urodynamic machine.
In addition, except right adrenal hemorrhage, no abnormality was observed in the ultrasonography of the kidneys with Doppler flow study of the aorta and renal arteries.
For improvement of ultrasonography application for detection of ovarian torsion, Doppler flow study has been employed aimed to assist clinicians in reaching the more accurate diagnosis of ovarian torsion.7 Because the accuracy of conventional sonography remains controversial in diagnosis of ovarian torsion, the aim of the present study was to examine the diagnostic performance of sonography for detection of ovarian torsion compared with surgical observation.
Although our patient could not urinate before the surgery, as seen in the pressure flow study, she did urinate easily after surgery during the uroflow investigation.
The channel fluid flow study was computed and model surface plot which showed the velocity magnitude would be generated.
The black void of a cerebral blood flow study is quite stark, as is a massive stroke imaged by CT or MRI.
For the purpose of steady flow study, the Venturi type test section geometry used by Barre (4) was adopted in the first step.
Since power flow calculation started in 1956 [1-3], a variety of numerical methods have been developed for power flow study, such as Gauss method [1], Newton method [4], and fast decoupled method [5].
- Shallow, high grade gold production and cash flow study underway at Artisanal Mining Zone at Crater Mountain
Internal sphincter electromyography (EMG) is helpful in assessing sphincter contraction during the staccato interruptions of the flow study.