Abstract The viscoelasticity and subharmonic generation of a kind of lipid ultrasound contrast agent are investigated. Based on the measurement of the sound attenuation spectrum, the viscoelasticity of the lipid shell is estimated by use of an optimization method. Shear modulus GS=10MPa and shear viscosity $\mu_{\rm S}$=1.49N$\cdot$S/m2 are obtained. The nonlinear oscillation of the encapsulated microbubble is studied with Church's model theoretically and experimentally. Especially, the dependence of subharmonic on the incident acoustic pressure is studied. The results reveal that the development of the subharmonic undergoes three stages, i.e. occurrence, growth and saturation, and that hysteresis appears in descending ramp insonation.
Received: 17 December 2005
Revised: 02 February 2006
Accepted manuscript online:
Fund: Project supported by the National Natural Science Foundation of China (Grant Nos 10274032 and
320200265), National Natural Science Foundation of Jiangsu Province, China (Grant No BK2004081).
Cite this article:
Gong Yan-Jun (龚燕君), Zhang Dong (章东), Gong Xiu-Fen (龚秀芬), Tan Kai-Bin (谭开彬), Liu Zheng (刘政) The viscoelasticity of lipid shell and the hysteresis of subharmonic in liquid containing microbubbles 2006 Chinese Physics 15 1526
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