title: Direct computation of ultrasound phased-array driving signals from a specified temperature distribution for hyperthermia.
abstract: This paper presents a new method which obtains ultrasound hyperthermia applicator phased-array element driving signals from a desired temperature distribution. The approach combines a technique which computes array element driving signals from focal point locations and intensities with a new technique which calculates focal point locations and power deposition values from temperature requirements. Temperature specifications appear here as upper and lower bounds within the tumor volume, and a focal point placement algorithm chooses focal patterns capable of achieving the temperature range objective. The linear algebraic structure of the method allows rapid calculation of both the phased-array driving signals and an approximate temperature field response. Computer simulations verify the method with a spherical section array (SSA) for a variety of temperature specifications and blood perfusion values. This scheme, which applies to any phased-array geometry, completes an essential step in both treatment planning and feedback for hyperthermia with ultrasound phased-array applicators.
authors.affiliation: Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor 48109.
authors.forename: R J
authors.initials: RJ
authors.lastname: McGough
authors.forename: E S
authors.initials: ES
authors.lastname: Ebbini
authors.forename: C A
authors.initials: CA
authors.lastname: Cain
mesh_terms: D000162:Acoustics; D000465:Algorithms; D003198:Computer Simulation; D006801:Humans; D006979:Hyperthermia, Induced / Q000379:methods / Q000592:standards*; D012815:Signal Processing, Computer-Assisted; D013814:Thermal Conductivity; D013817:Thermography / Q000379:methods / Q000592:standards*; D014463:Ultrasonography / Q000379:methods / Q000592:standards*