Comparison of Flow Measure Techniques during Continuous and Pulsatile Flow


Class: BE310
Group: M2
Members: Bookbinder, Engler, Hong, Miller
Date:May, 2001

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Abstract:
Our experimental objectives were to compute the integrated flow rates for square and EKG pulse flow from ?P traces and also to compare thermodilution, Poiseuille flow, and integrated flow calculations to experimentally measured flow rates.   Thermodilution was performed using the Schwan-Ganz catheter and associated calculations.  Poiseuille flow was found from pressure traces taken across a pressure drop.  Determining the integrated flow rates involved an integrated form of the 1-D Navier-Stokes equation, following some simplifying assumptions.   When examining the accuracy of the experiment from linear regression and dimensionless analysis, the thermodilution calculation was most accurate over the whole fluid flow range, with the Poiseuille calculation differing only significantly at higher flow rates due to flows above the turbulence threshold (large Reynolds’ Numbers).  Thus, near idealized linear inviscid flow occurred at the lower speeds, as the flow rate calculations do not differ significantly.  For the pulsatile flow calculations, the integration method resulted in more accurate flow rates than the Poiseuille calculations.  While it was determined that the thermodilution method was the most accurate (losing only a small amount of accuracy at higher flows), it was shown that it was not significantly different from the integrated flow calculations.  This indicates that both integrated flow and thermodilution flow calculations are accurate predictors of flow over a wide range of fluid velocities.