Direct Measurement of Blood Flow Reflections by Plane-wave Ultrasound

Pressure and blood flow reflections due to downstream impedance mismatches in arteries are associated with disease and organ damage. Changes in the magnitude of blood flow reflections in the common carotid artery may indicate impaired cerebral autoregulation related to stroke, sickle cell anemia, Alzheimer's, or other diseases. Established methods analyze pressure or flow waveform characteristics, and have low accuracy and depend on the location of measurement due to the overlap between forward and reflected waves. Current research methods of separating forward and reflected blood flow in time require the indirect measurement of pulse wave velocity, blood vessel cross-sectional area, blood flow, and involve multi-cardiac cycle synchronization. We propose a new, ultrafast ultrasound imaging method using plane acoustic waves, reaching sufficient frame rates to directly capture the pulse wave while acquiring all information necessary to isolate the reflected waveform in time, improving the accuracy, robustness, and practicality of the measurement.%%%%M.Sc.