title: Study of a peak in cavitation activity from HIFU exposures using TA fluorescence.
abstract: Methods of measuring the sound field and focal region of a 1.05 MHz high intensity focused ultrasound (HIFU) are described in this paper. 1.05 MHz pulsed HIFU with intensity 2400 W/cm(2) with a 1:1 duty cycle ("on" phase equaled "off" phase) was used to irradiate terephthalic acid (TA). Pulse periods of 0.5 ms, 1 ms, 3.3 ms, 10 ms, 15 ms, 33 ms, 0.1s and 1s were used. The irradiation time was 2 min. To indicate the intensity of inertial cavitation activity, the fluorescence intensity of hydroxyterephthalic acid (HTA) was measured. The result shows that the cavitation activity of pulsed HIFU peaks at a pulse period of 10 ms, cavitation activity is significantly greater for pulse periods from 2 to 20 ms than for others.
authors.affiliation: State Key Laboratory of Hydrology-water Resources and Hydraulic Engineering, Department of Computer and Information Engineering, Hohai University, ChangZhou, PR China. cpzhu5126081@hhuc.edu.cn <cpzhu5126081@hhuc.edu.cn>
authors.forename: Changping
authors.initials: C
authors.lastname: Zhu
authors.forename: Shichuan
authors.initials: S
authors.lastname: He
authors.forename: Minglei
authors.initials: M
authors.lastname: Shan
authors.forename: Jiacai
authors.initials: J
authors.lastname: Chen
mesh_terms: D004307:Dose-Response Relationship, Radiation; D005740:Gases / Q000737:chemistry* / Q000528:radiation effects*; D010795:Phthalic Acids / Q000737:chemistry* / Q000528:radiation effects*; D011829:Radiation Dosage; D013050:Spectrometry, Fluorescence / Q000379:methods*; D014464:Ultrasonic Therapy; D014465:Ultrasonics
chemical_list: D005740:Gases; D010795:Phthalic Acids; C011363:terephthalic acid