METHOD AND APPARATUS FOR ESTIMATING THE ULTRASOUND ATTENUATION-VS-FREQUENCY SLOPE OF A PROPAGATION MEDIUM FROM THE COMPLEX ENVELOPE OF A SIGNAL

摘要

Method and apparatus for estimating the ultrasound attenuation - vs - frequency slope of a propagation medium from the complex envelope of a signal. An ultrasound attenuation scanner measures the local attenuation of tissues from pulse echo A-line data. An adaptive filter (60) with a transfer function which is the inverse of the tissue (25) undergoing examination operates on the complex envelope (?o(n)) of the RF signal. The filter (60) together with an FM detector (65) and an accumulator (70) functions as a negative feedback loop which continually maintains the filter characteristic as the inverse of the frequency dependent characteristic of the tissue (25).