PARENT SESSION
1:30 PM to 3:30 PM
Saturday, April 20, 2002
Poster Session 1 Noninvasive Treatment Monitoring and Treatment Planning
Room: Nevada 1-2

(MP01-10) Fast calculations of the nearfield pressure generated by rectangular ultrasound transducers.

McGough, Robert^*,1, ¹ Duke University Medical Center, Durham, NC

ABSTRACT-
An improved technique for numerically calculating the nearfield pressure predicted by the Rayleigh-Sommerfeld diffraction integral is demonstrated for continuous-wave excitations applied to a rectangular ultrasound source. This technique superposes single integral expressions for the nearfield pressure that avoid the numerical problems produced by the impulse response formulation. These numerical problems, which are often associated with the edges of a rectangular source, are eliminated when a numerical singularity is subtracted from the integral expression. The improved technique, when compared to the impulse response method and the rectangular radiator method of Ocheltree and Frizzell, consistently demonstrates smaller numerical errors and shorter computation times. This result is attributed to the rapid convergence of the single-integral technique presented here, which simultaneously increases the numerical accuracy and reduces the time required for numerical computations.

KEYWORDS: ultrasound, nearfield computations, transducer