Phase Locked LDA Measurements of Pulsatile Flow Through Heart Valves- A Novel Stability Approach,
Abstract
The presence of turbulence is blood flow through heart valves is indicative of valvular stenosis, depending on the phase of the cardiac cycle. Comparative studies of normal and stenosed valves show that maximum turbulence level is achieved during the decelerating phase (diastole). The spectra obtained during the rapid closure stage of the valves was found to be governed by dominant modes that stem from the stenosis geometry and the valve's leaflets vibrations. The traditional analysis of transition to turbulence draws upon a stability diagram where the fundamental heart rate is taken as a (the Wormersley parameter). A novel approach which involves the decomposition of alpha into its frequency components is suggested here. The novel stability approach distinguishes between stabilizing and destabilizing modes apparent in the flow and depicts an unbiased and accurate ability diagram of the flow. The traditional stability approach was found to be biased towards overrated unstable flow conditions, thus failing to represent an accurate flow stability criteria. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 23, 1992
- Accession Number
- ADP008922
Entities
People
- D. Bluestein
- S. Einav
Organizations
- Tel Aviv University