Related Experiment Video
Updated: Aug 15, 2026

Parallel-plate Flow Chamber and Continuous Flow Circuit to Evaluate Endothelial Progenitor Cells under Laminar Flow Shear Stress
Published on: January 17, 2012
Automated computation of relative flow resistance using a pulsed Doppler flowmeter
H D Battarbee1, W Johnson, G E Farrar
1Department of Physiology and Biophysics, Louisiana State University Medical Center, School of Medicine in Shreveport 71130.
Abstract:
Use of a pulsed Doppler flowmeter to assess changes in blood flow resistance often requires a laborious series of calculations, and full characterization of resistance changes frequently necessitates replotting of calculated data. To facilitate the interpretation of pulsed Doppler flowmetry data, a simple, inexpensive device was constructed that computes the signal ratio of mean arterial pressure (MAP) to directional pulsed Doppler outputs. With this device, relative flow resistance can be recorded and quantitatively assessed at a glance in three vascular beds in real time. This computer-like device was designed around the Burr-Brown DIV100HP integrated circuit. C741G OpAmps provide input buffering, zeroing, and ranging adjustments enabling the user to accurately follow resistance over a very broad range of changes without exceeding the device's operating limits. A LM339 quad comparator monitors the input of each DIV100 and indicates when operating limits are exceeded via a channel-specific LED indicator and an audible alarm. No significant attenuation of the input signals occurs over the range of direct current to 50 kHz, and the output is without significant phase shift. Comparisons with calculated changes in resistance derived from the MAP and pulsed Doppler flowmetry in unanesthetized, unrestrained rats confirmed that resistance changes can be measured with precision and accuracy.
Related Concept Videos
Poiseuille's Law and Reynolds Number
Fast Decoupled and DC Powerflow
General Characteristics of Pipe Flow I
The classification of fluid...
Pipe Flowrate Measurement
The orifice meter is a simple,...
Pipe Flowrate Measurement: Problem Solving
Rapidly Varying Flow

