title: Quantitative testing of physiotherapy ultrasound beam patterns within a clinical environment using a thermochromic tile.
abstract: The implementation of the non-standardized method developed at the National Physical Laboratory (UK) supporting the quality assurance of therapeutic ultrasonic beam parameters within a clinical environment is presented. The method consists of exposing an acoustic absorber tile, part of which contains a thermochromic pigment, to the ultrasonic beam, thereby forming an image of the two-dimensional intensity profile of the transducer. Nine different physiotherapy ultrasound treatment heads currently used clinically were tested using this method. Thermochromic images were postprocessed in order to estimate the Effective Radiating Area (ERA) for treatment heads operating within the frequency range from 1 MHz to 3.2 MHz, and nominal applied intensities in the range of 1-3 W/cm(2). Experimental results and comparisons with manufacturer specified values of ERA are presented. Differences in the experimentally derived results and the manufacturer values are typically well within 25%. The root-mean squared difference calculated over the nine treatment heads is 15.1%, with the thermochromic material tended to underestimate the ERA.
authors: University of Rijeka, Medical Faculty, Department of Physics, Braće Branchetta 20, 51 000 Rijeka, Croatia. Electronic address: gordana.zauhar@medri.uniri.hr.
authors: Gordana
authors: G
authors: Žauhar
authors: Clinical Hospital Rijeka, Medical Physics Department, Krešimirova 42, 51 000 Rijeka, Croatia. Electronic address: jenny_smilrad@net.hr.
authors: Đeni Smilović
authors: ĐS
authors: Radojčić
authors: Clinical Hospital Rijeka, Department for Physical and Rehabilitation Medicine, Tome Strižića 3, 51000 Rijeka, Croatia. Electronic address: dobravac@gmail.com.
authors: Denis
authors: D
authors: Dobravac
authors: Clinical Hospital Rijeka, Medical Physics Department, Krešimirova 42, 51 000 Rijeka, Croatia. Electronic address: slaven.jurkovic@medri.uniri.hr.
authors: Slaven
authors: S
authors: Jurković
mesh_terms: D006257:Head; D006801:Humans; D026741:Physical Therapy Modalities / Q000295:instrumentation*; D011785:Quality Assurance, Health Care; D014159:Transducers; D014464:Ultrasonic Therapy / Q000295:instrumentation* / Q000379:methods
keywords: Effective radiating area; Quality assurance; Thermochromic material; Ultrasound therapy