Cameron MacGregor (MHSc): Using 16 versus 256 channels to map microbubble activity in a brain-therapeutic ultrasound application: a tale of two digitizers

March 28, 2018 @ 9:00 am – 9:30 am
Rosebrugh Building
Rosebrugh Bldg, Toronto, ON M5S 3G9

Room: RS 211


Therapeutic ultrasound is an emerging treatment modality that makes use of propagating mechanical waves to elicit changes in tissue. One area under investigation is the application of therapeutic ultrasound for temporary and reversible opening of the blood-brain barrier (BBB), whereby stabilized microbubbles introduced into the bloodstream undergo radial oscillation within the sound field, detaching tight junctions between endothelial cells allowing otherwise blocked drugs to temporarily enter neural tissue. In vivo studies suggest that the information provided by nonlinear re-radiation of acoustic energy from the microbubble population can be used to calibrate the treatment pressures to a safe yet effective level. The digitization and processing of the pressures re-radiated by the microbubbles should be fast and accurate to facilitate real-time treatment calibration. In this presentation, the in-system performance of the AlazarTech ATS9416 16 channel digitizer will be compared against two 128-channel Ultrasonix SonixDAQ digitizers using the time exposure acoustics algorithm for mapping bubble activity. The trade-off of lowering the number of channels causing reduced quality in the bubble activity map versus the advantages of lowered data transfer latency and processing time – reflected in the inherent strengths and weaknesses of each digitizer – will be discussed, as well as other implementation issues within the context of a previously developed prototype brain therapy system.