title: Design and experiment of 256-element ultrasound phased array for noninvasive focused ultrasound surgery.
abstract: A 256-element phased array high intensity focused ultrasound system has been designed and constructed in our laboratory. The 256-element spherical-section ultrasound phased array made from piezocomposite material operates at 1.1 MHz with 11-cm radius of curvature, 14-cm outer diameter, and 3.4-cm diameter central hole for mounting diagnostic ultrasound imaging probe. First, the explicit sound field calculation approach for the spherical-section phased array and the genetic optimal algorithm are briefly introduced as the optimal focus pattern control methods. Then, the design guidelines of 256-element spherical-section focused ultrasound phased array and 256-channel driver system are given. The results of single on and off axial focus, multiple on and off axial foci, half sub-array focus pattern provide further evidence for the 3D focus steering and sub-array mode for avoiding obstacles in focused ultrasound surgery. The multi-foci pattern can enlarge the treatment volume to 22 times larger than that of a single focus in one sonication. Finally, in vitro and transparent tissue-mimicking phantom experiment results confirm the ability of 256-element spherical-section phased array system to induce thermal lesions for noninvasive ultrasound surgery.
authors.affiliation: The Key Laboratory of Biomedical Information Engineering of Ministry of Education, Department of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, PR China. mzlu@mail.xjtu.edu.cn <mzlu@mail.xjtu.edu.cn>
authors.forename: Mingzhu
authors.initials: M
authors.lastname: Lu
authors.forename: Mingxi
authors.initials: M
authors.lastname: Wan
authors.forename: Feng
authors.initials: F
authors.lastname: Xu
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Wang
authors.forename: Xiaozhen
authors.initials: X
authors.lastname: Chang
mesh_terms: D004867:Equipment Design; D019544:Equipment Failure Analysis; D019060:Minimally Invasive Surgical Procedures / Q000295:instrumentation* / Q000379:methods; D019047:Phantoms, Imaging; D014159:Transducers; D014464:Ultrasonic Therapy / Q000295:instrumentation* / Q000379:methods