FRINK Linked Data Fragments server

Matches in SemOpenAlex for { <https://semopenalex.org/work/W420009968> ?p ?o ?g. }

• W420009968 abstract "The primary objective of this thesis was to model and simulate aortic flow and mitral regurgitation and to improve quantitative ultrasound measurements. The tools used were; theoretical analysis, computer simulation, model experiments, image analysis and clinical evaluation.The flow in the aorta is known to be influenced by both cardiac function and vascular characteristics. The influence of vascular characteristics were investigated in a three parameter windkessel model. Peak aortic velocity and acceleration were studied when these parameters were changed. The results indicate that aortic peak flow velocity is related to the compliance of the arterial system while the peak flow acceleration is inversely related to the characteristic impedance of the aorta and large vessels.To obtain a correct aortic flow velocity profile from a two dimensional colour flow echocardiographic investigation, a unit which incrementally delayed the ECG signal was designed and used to control the ultrasound scanning. By combining velocity data from incrementally delayed images in a software program, a time corrected profile was obtained.In order to determine regurgitant heart valve flow volume, the intensity of the ultrasound continuous wave signal has been suggested as a potential method. Measurements in a hydraulic model showed, however, that the intensity of the signal was, in addition to volume, also related to peak velocity, measuring angle and machine settings. Hence, conclusions drawn about regurgitant grade from the intensity signal require caution.Another method for determination of valve regurgitation is to study the laminar and nondisturbed flow in the region of acceleration proximal to the valve, normally the distance from orifice to the first aliased velocity. This was tested first in a steady flow model using colour M mode and colour 2D information, and later in a pulsatile flow model. Four different methods using velocity data from the entire reconstructed 2D velocity vector field were investigated. Model experiments and error calculation showed that flow was best determined by integrating velocities along hemi-spherical lines in two perpendicular planes within an angle of ±45° from the orifice centre line at a distance of approximately 1.2 to 1.4 times the orifice diameter, corresponding to velocities between 0.15 and 0.45 m/s. By combining 2D flow and spectral velocity data, regurgitant volume could be estimated for both circular, diagonal and crescent orifices to within + 15 to -11% from true volume." @default.
• W420009968 created "2016-06-24" @default.
• W420009968 creator A5001589609 @default.
• W420009968 date "1993-01-01" @default.
• W420009968 modified "2023-09-24" @default.
• W420009968 title "Cardiovascular modelling and ultrasound heart flow quantification : aortic flow and mitral regurgitation" @default.
• W420009968 hasPublicationYear "1993" @default.
• W420009968 type Work @default.
• W420009968 sameAs 420009968 @default.
• W420009968 citedByCount "0" @default.
• W420009968 crossrefType "journal-article" @default.
• W420009968 hasAuthorship W420009968A5001589609 @default.
• W420009968 hasConcept C117896860 @default.
• W420009968 hasConcept C121332964 @default.
• W420009968 hasConcept C126322002 @default.
• W420009968 hasConcept C126838900 @default.
• W420009968 hasConcept C136229726 @default.
• W420009968 hasConcept C143753070 @default.
• W420009968 hasConcept C158846371 @default.
• W420009968 hasConcept C164705383 @default.
• W420009968 hasConcept C166693061 @default.
• W420009968 hasConcept C178853913 @default.
• W420009968 hasConcept C2776029896 @default.
• W420009968 hasConcept C2776229121 @default.
• W420009968 hasConcept C2777543888 @default.
• W420009968 hasConcept C2779980429 @default.
• W420009968 hasConcept C2780168065 @default.
• W420009968 hasConcept C2780714102 @default.
• W420009968 hasConcept C2993373945 @default.
• W420009968 hasConcept C38349280 @default.
• W420009968 hasConcept C57879066 @default.
• W420009968 hasConcept C62520636 @default.
• W420009968 hasConcept C71924100 @default.
• W420009968 hasConcept C74650414 @default.
• W420009968 hasConcept C93038891 @default.
• W420009968 hasConceptScore W420009968C117896860 @default.
• W420009968 hasConceptScore W420009968C121332964 @default.
• W420009968 hasConceptScore W420009968C126322002 @default.
• W420009968 hasConceptScore W420009968C126838900 @default.
• W420009968 hasConceptScore W420009968C136229726 @default.
• W420009968 hasConceptScore W420009968C143753070 @default.
• W420009968 hasConceptScore W420009968C158846371 @default.
• W420009968 hasConceptScore W420009968C164705383 @default.
• W420009968 hasConceptScore W420009968C166693061 @default.
• W420009968 hasConceptScore W420009968C178853913 @default.
• W420009968 hasConceptScore W420009968C2776029896 @default.
• W420009968 hasConceptScore W420009968C2776229121 @default.
• W420009968 hasConceptScore W420009968C2777543888 @default.
• W420009968 hasConceptScore W420009968C2779980429 @default.
• W420009968 hasConceptScore W420009968C2780168065 @default.
• W420009968 hasConceptScore W420009968C2780714102 @default.
• W420009968 hasConceptScore W420009968C2993373945 @default.
• W420009968 hasConceptScore W420009968C38349280 @default.
• W420009968 hasConceptScore W420009968C57879066 @default.
• W420009968 hasConceptScore W420009968C62520636 @default.
• W420009968 hasConceptScore W420009968C71924100 @default.
• W420009968 hasConceptScore W420009968C74650414 @default.
• W420009968 hasConceptScore W420009968C93038891 @default.
• W420009968 hasLocation W4200099681 @default.
• W420009968 hasOpenAccess W420009968 @default.
• W420009968 hasPrimaryLocation W4200099681 @default.
• W420009968 hasRelatedWork W1967532890 @default.
• W420009968 hasRelatedWork W1977584838 @default.
• W420009968 hasRelatedWork W1985163163 @default.
• W420009968 hasRelatedWork W1998689586 @default.
• W420009968 hasRelatedWork W2001698818 @default.
• W420009968 hasRelatedWork W2010958918 @default.
• W420009968 hasRelatedWork W2024458222 @default.
• W420009968 hasRelatedWork W2029414304 @default.
• W420009968 hasRelatedWork W2043984266 @default.
• W420009968 hasRelatedWork W2060852674 @default.
• W420009968 hasRelatedWork W2071310018 @default.
• W420009968 hasRelatedWork W2082221508 @default.
• W420009968 hasRelatedWork W2112962306 @default.
• W420009968 hasRelatedWork W2137493737 @default.
• W420009968 hasRelatedWork W2170679557 @default.
• W420009968 hasRelatedWork W2360998712 @default.
• W420009968 hasRelatedWork W2407706534 @default.
• W420009968 hasRelatedWork W2417489287 @default.
• W420009968 hasRelatedWork W3212709604 @default.
• W420009968 hasRelatedWork W2189417319 @default.
• W420009968 isParatext "false" @default.
• W420009968 isRetracted "false" @default.
• W420009968 magId "420009968" @default.
• W420009968 workType "article" @default.