title: Air-coupled acoustic radiation force for non-contact generation of broadband mechanical waves in soft media.
abstract: A non-contact method for efficient, non-invasive excitation of mechanical waves in soft media is proposed, in which we focus an ultrasound (US) signal through air onto the surface of a medium under study. The US wave reflected from the air/medium interface provides radiation force to the medium surface that launches a transient mechanical wave in the transverse (lateral) direction. The type of mechanical wave is determined by boundary conditions. To prove this concept, a home-made 1 MHz piezo-ceramic transducer with a matching layer to air sends a chirped US signal centered at 1 MHz to a 1.6 mm thick gelatin phantom mimicking soft biological tissue. A phase-sensitive (PhS)-optical coherence tomography system is used to track/image the mechanical wave. The reconstructed transient displacement of the mechanical wave in space and time demonstrates highly efficient generation, thus offering great promise for non-contact, non-invasive characterization of soft media, in general, and for elasticity measurements in delicate soft tissues and organs in bio-medicine, in particular.
authors: Łukasz
authors: 0000-0002-3311-2821
authors: Ł
authors: Ambroziński
authors: Ivan
authors: 0000-0003-4323-9321
authors: I
authors: Pelivanov
authors: Department of Bioengineering, University of Washington , Seattle, Washington 98195, USA.
authors: Shaozhen
authors: S
authors: Song
authors: Department of Bioengineering, University of Washington , Seattle, Washington 98195, USA.
authors: Soon Joon
authors: SJ
authors: Yoon
authors: David
authors: D
authors: Li
authors: Department of Bioengineering, University of Washington , Seattle, Washington 98195, USA.
authors: Liang
authors: L
authors: Gao
authors: Tueng T
authors: TT
authors: Shen
authors: Ruikang K
authors: 0000-0001-6823-9139
authors: RK
authors: Wang
authors: Department of Bioengineering, University of Washington , Seattle, Washington 98195, USA.
authors: Matthew
authors: M
authors: O'Donnell