title: Effective radiating area and beam non-uniformity ratio of ultrasound transducers at 5MHz, according to IEC 61689:2007.
abstract: This paper discloses results of measuring the effective radiating area (A(ER)) and the beam non-uniformity ratio (R(BN)) for US transducers at 5.0 MHz. Measurements were carried out at Laboratory of Ultrasound of the Brazilian National Institute of Metrology, Standardization, and Industrial Quality. As reliability proof of system's adequacy, uncertainties were assessed. The calculation protocol was developed based on standard IEC 61689:2007. Type A uncertainty was estimated after four repetitions of the full procedure for the determination of A(ER) and R(BN), and Type B uncertainty was estimated from the mathematical model for both calculations, obtained from IEC 61689:2007 and the guide to the expression of uncertainty in measurement. The procedure presented herein represents the state of the art regarding metrology for testing therapeutic ultrasound devices, and its application results in fundamental aspects to support their evaluation regarding quality assurance, for instance, for a certification process due safety and performance.
authors.affiliation: Laboratory of Ultrasound/National Institute of Metrology, Standardization, Industrial Quality (Inmetro), Duque de Caxias, RJ, Brazil. rpfelix@inmetro.gov.br
authors.forename: Rodrigo P B
authors.initials: RP
authors.lastname: Costa-Félix
authors.forename: André V
authors.initials: AV
authors.lastname: Alvarenga