Robert Krutsch, Freescale Semiconductor
EETimes (7/5/2011 12:29 AM EDT)
A critical factor in the design of many medical ultrasound equipment designs is the effectiveness of the beamforming algorithms, a signal processing technique used in sensor arrays for directional signal transmission or reception. But until recently, the computational power needed to do such signal processing – at a reasonable cost and with the resolution needed for medical diagnostic purposes – was only possible with FPGAs and ASICS.
Now, however a new generation of dedicated digital signal processing architectures can bring a lot of processing power and highly parallel architectures to the problem at a much lower cost and at lower power.
This article describes how to use a Freescale DSP MSC8156 loaded with software libraries for B-Mode images that produce diagnostically useful medical ultrasound imaging results, using no more than about 38% of the resources of the DSP, leaving enough room to also fit Doppler Imaging modes.
In B-mode ultrasound, a linear array of transducers simultaneously scans a plane through the body that can be viewed as a two-dimensional image on screen, whereas in the Doppler mode, the ultrasound system makes use of the well-known Doppler effect to measure and visualize blood flow.
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