title: Uniform pulsed fields for ultrasonic bioeffect experimentation.
abstract: The rationale and methods are presented for producing high amplitudes of pulsed ultrasound distributed uniformly over several square centimetres. Pulsed fields (p = 1 MPa, 1-9 pulses per burst, up to 10(4) bursts per second, pulse-average intensity up to 39 W cm-2, centre frequencies 1, 2.5 and 3.5 MHz) were produced using high power pulsers and minimally damped 3.8 cm diameter transducers. Wave-forms and negative pressure distributions in water are displayed for these transducers. The lateral distributions of pressure amplitudes were uniform within +/- 15% over areas up to 4 cm2. These fields are suitable for use in bioeffect experiments to investigate possible health hazards of diagnostic pulsed ultrasound, as well as for possible therapeutic applications.
authors.affiliation: Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore 21201.
authors.forename: G H
authors.initials: GH
authors.lastname: Harrison
authors.forename: E K
authors.initials: EK
authors.lastname: Balcer-Kubiczek
mesh_terms: D008722:Methods; D014159:Transducers; D014465:Ultrasonics