Advantages in using multifrequency excitation of contrast microbubbles for enhancing echo particle image velocimetry techniques: initial numerical studies using rectangular and triangular waves.
Zheng H, Mukdadi O, Kim H, Hertzberg JR, Shandas R. Advantages in using multifrequency excitation of contrast microbubbles for enhancing echo particle image velocimetry techniques: initial numerical studies using rectangular and triangular waves. Ultrasound Med Biol. 2005 Jan; 31(1):99-108.