Volume 113, Issue 4, April 2003
Index of content:
- ACOUSTICAL MEASUREMENTS AND INSTRUMENTATION 
113(2003); http://dx.doi.org/10.1121/1.1559174View Description Hide Description
Two-dimensional simulations with propagation through two different heterogeneous human body wall models have been performed to analyze different correction filters for ultrasonic wave aberration due to forward wave propagation. The different models each produce most of the characteristicaberrationeffects such as phase aberration, relatively strong amplitude aberration, and waveform deformation. Simulations of wave propagation from a point source in the focus (60 mm) of a 20 mm transducer through the body wall models were performed. Center frequency of the pulse was 2.5 MHz. Corrections of the aberrations introduced by the two body wall models were evaluated with reference to the corrections obtained with the optimal filter: a generalized frequency-dependent phase and amplitude correction filter [Angelsen, Ultrasonic Imaging (Emantec, Norway, 2000), Vol. II]. Two correction filters were applied, a time delay filter, and a time delay and amplitude filter. Results showed that correction with a time delay filter produced substantial reduction of the aberration in both cases. A time delay and amplitude correction filter performed even better in both cases, and gave correction close to the ideal situation (no aberration). The results also indicated that the effect of the correction was very sensitive to the accuracy of the arrival time fluctuations estimate, i.e., the time delay correction filter.