title: Low acoustic attenuation silicone rubber lens for medical ultrasonic array probe.
abstract: Effects of heavy density (rho = 9.2 x 10(3) kg/m(3)) Yb(2)O(3) fine dopant (16 nm in diameter) on the acoustic properties of a high-temperature-vulcanization (HTV) silicone rubber have been investigated, to develop a new acoustic lens material with a low acoustic attenuation (alpha) for the medical array probe application. The HTV silicone rubber has advantages in that it shows a lower alpha than that of a room-temperature-vulcanization (RTV) silicone rubber and it can be mixed by applying shear stress, using roll-milling equipment. Roll-milling time dependence of the HTV silicone rubber indicates that the alpha is closely affected by the dispersion of nanopowders in the rubber matrix. The 8 vol% Yb(2)O(3)-doped HTV silicone rubber mixed for 30 min showed the lowest alpha of 0.73 dB/mm MHz with an acoustic impedance [AI = sound speed (c) x density (rho)] of 1.43 x 10(6) kg/m(2)s at 37 degrees C. Moreover, simulation results reveal that a 5 MHz linear probe using the HTV silicone rubber doped with Yb(2)O(3) powder showed relative sensitivity around 2.6 to 3.0 dB higher than a probe using RTV silicone rubber doped with Yb(2)O(3) powder or SiO2-doped conventional silicone rubber for the ultrasonic medical application.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Itsumi
authors.forename: Yasuharu
authors.initials: Y
authors.lastname: Hosono
authors.forename: Noriko
authors.initials: N
authors.lastname: Yamamoto
authors.forename: Yohachi John
authors.initials: YJ
authors.lastname: Yamashita
mesh_terms: D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007909:Lenses; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012826:Silicone Elastomers / Q000737:chemistry*; D014159:Transducers; D014463:Ultrasonography / Q000295:instrumentation*
chemical_list: D012826:Silicone Elastomers