title: A feasibility study ofin vivoapplications of single beam acoustic tweezers.
abstract: Tools that are capable of manipulating micro-sized objects have been widely used in such fields as physics, chemistry, biology, and medicine. Several devices, including optical tweezers, atomic force microscope, micro-pipette aspirator, and standing surface wave type acoustic tweezers have been studied to satisfy this need. However, none of them has been demonstrated to be suitable forin vivoand clinical studies. Single beam acoustic tweezers (SBAT) is a technology that uses highly focused acoustic beam to trap particles toward the beam focus. Its feasibility was first theoretically and experimentally demonstrated by Lee and Shung several years ago. Since then, much effort has been devoted to improving this technology. At present, the tool is capable of trapping a microparticle as small as 1μm, as well as a single red blood cell. Although in comparing to other microparticles manipulating technologies, SBAT has advantages of providing stronger trapping force and deeper penetration depth in tissues, and producing less tissue damage, its potential forin vivoapplications has yet been explored. It is worth noting that ultrasound has been used as a diagnostic tool for over 50 years and no known major adverse effects have been observed at the diagnostic energy level. This paper reports the results of an initial attempt to assess the feasibility of single beam acoustic tweezers to trap microparticlesin vivoinside of a blood vessel. The acoustic intensity of SBAT under the trapping conditions that were utilized was measured. The mechanical index and thermal index at the focus of acoustic beam were found to be 0.48 and 0.044, respectively, which meet the standard of commercial diagnostic ultrasound system.
authors.affiliation: NIH Transducer Resource Center and Department of Biomedical Engineering, University of Southern California , Los Angeles, California 90089-1111, USA.
authors.forename: Ying
authors.initials: Y
authors.lastname: Li
authors.affiliation: NIH Transducer Resource Center and Department of Biomedical Engineering, University of Southern California , Los Angeles, California 90089-1111, USA.
authors.forename: Changyang
authors.identifier: 0000-0002-3746-7304
authors.initials: C
authors.lastname: Lee
authors.affiliation: NIH Transducer Resource Center and Department of Biomedical Engineering, University of Southern California , Los Angeles, California 90089-1111, USA.
authors.forename: Ruimin
authors.initials: R
authors.lastname: Chen
authors.affiliation: NIH Transducer Resource Center and Department of Biomedical Engineering, University of Southern California , Los Angeles, California 90089-1111, USA.
authors.forename: Qifa
authors.initials: Q
authors.lastname: Zhou
authors.affiliation: NIH Transducer Resource Center and Department of Biomedical Engineering, University of Southern California , Los Angeles, California 90089-1111, USA.
authors.forename: K Kirk
authors.initials: KK
authors.lastname: Shung