title: Study to prevent the density of microcapsules from diffusing in blood vessel by local acoustic radiation force.
abstract: We have already reported our attempt to constrain direction of microcapsules in flow owing to an acoustic radiation force. However, the diameter of capsules was too large not to be applied in vivo. Furthermore, acoustic radiation force affected only in focal area because focused ultrasound was used. Thus we have improved our experiment by using microcapsules as small as blood cells and introducing a plane wave of ultrasound. We prepared an artificial blood vessel including a Y-form bifurcation established two observation areas. Then we newly defined the induction index to evaluate the difference of capsule density in two paths of downstream. As the result, optimum angle of ultrasound emission to induce to desired path was derived. And the induction index increased in proportion to the central frequency of ultrasound, which is affected by forming aggregation of capsules to receive more radiation force.
authors.affiliation: Graduate School of Bio-Applications and Systems Engineering, Tokyo University of Agriculture and Technology, Koganei, 184-8588 Japan. masuda_k@cc.tuat.ac.jp
authors.forename: Kohji
authors.initials: K
authors.lastname: Masuda
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Watarai
authors.forename: Ryusuke
authors.initials: R
authors.lastname: Nakamoto
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Miyamoto
authors.forename: Keri
authors.initials: K
authors.lastname: Kim
authors.forename: Toshio
authors.initials: T
authors.lastname: Chiba
mesh_terms: D000465:Algorithms; D001808:Blood Vessels / Q000502:physiology*; D002214:Capsules / Q000737:chemistry*; D004058:Diffusion; D016503:Drug Delivery Systems / Q000379:methods*; D006801:Humans; D045423:Microbubbles; D008955:Models, Cardiovascular; D014463:Ultrasonography / Q000379:methods*
chemical_list: D002214:Capsules