SUPPORT:
Background
Ultrasonic imaging is the preferred method for noninvasive tissue examination
and real-time blood flow analysis. Foreign items (e.g. radiolucent shrapnel)
embedded in the body can also be imaged. While this would greatly aide combat
field medics and civilian emergency medical technicians, current ultrasound
scanners are too large, heavy, and power-consumptive for battery operation.
Major scanner functions, size, weight and power must be significantly reduced
for portable operation.
The beamformer dynamically focuses, apodizes, and steers both transmitted and received ultrasonic waveforms. Modern beamformers typically utilize an analog-to-digital converter (ADC) at each element, followed by digital memory and signal processing circuitry. The beamformer is amenable to the extensive size, weight, and power reduction using charge-coupled device (CCD) technology. This technology is integrable with conventional CMOS. The proposed beamformer provides the same functionality as digital designs but at 1% their size, wieght, power and for 10% their cost, while increasing resolution ten-fold.
Current Work
Ultrasonic imaging is the preferred method for noninvasive tissue examination
and real-time blood flow analysis. Foreign items (e.g. radiolucent shrapnel)
embedded in the body can also be imaged. While this would greatly aide combat
field medics and civilian emergency medical technicians, current ultrasound
scanners are too large, heavy, and power-consumptive for battery operation.
Major scanner functions, size, weight and power must be significantly reduced
for portable operation.
The beamformer dynamically focuses, apodizes, and steers both transmitted and received ultrasonic waveforms. Modern beamformers typically utilize an analog-to-digital converter (ADC) at each element, followed by digital memory and signal processing circuitry. The beamformer is amenable to the extensive size, weight, and power reduction using charge-coupled device (CCD) technology. This technology is integrable with conventional CMOS. The proposed beamformer provides the same functionality as digital designs but at 1% their size, wieght, power and for 10% their cost, while increasing resolution ten-fold.
The following is a movie showing the results of color flow imaging interrogated along one beam reapeatedly using different beamforming techniques. The simulated flow phantom contained 1000s of strong randomly distributed stationary scatterers as well as 1000s of other weak scatterers moving at a 45 degree angle in a vessel. The flow was constant across the lumen of the vessel with a velocity of 1/3 wavelength per repetition (the absolute velocity is a function of the repetition interval which in this simulation is arbitrary). A 3.35MHz 25% bandwidth ultrasound pulse was used to insonify the tissue for flow information. A 50% bandwidth pulse was used to create the grayscale information. Three simulated beamformers were used to create the images you see below. A classic RF beamformer is presented at the left. A patented alternative method is shown in the middle and our current system is shown at the right.
Publications
Correspondence:
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Biomedical Ultrasonics Laboratory
Biomedical Engineering Department
University of Michigan
3304 G.G. Brown, 2350 Hayward
Ann Arbor, MI 48019-2125
734-764-8589
Link to: http://bul.eecs.umich.edu/research/handheld/