Subharmonic and ultraharmonic emissions based on the nonlinear oscillation of encapsulated microbubbles in ultrasound contrast agents  

作　　者：GONG Yanjun ZHANG Dong GONG Xiufen 

机构地区：[1]State Key Lab of Modern Acoustics, Institute of Acoustics, Nanjing University, Nanjing 210093, China

出　　处：《Chinese Science Bulletin》2005年第18期1975-1978,共4页

基　　金：This work was supported by the National Natural Science Foundation of China(Grant Nos.10074033 and 10274032);the N ational Natural Science Foundation of Jiangsu Province(BK2004081);SRF for ROCS.SEM.and TWAS(No.03-390).

摘　　要：Subharmonics or ultraharmonics provides better contrast-to-tissue ratio (CTR) than the fundamental or the second harmonics, having prospective application in medical diagnosis. In this paper, subharmonic and ultra-harmonic emissions are theoretically studied through nonlinear oscillation of encapsulated bubbles. The optimized frequencies for emissions of the subharmonics and ultra-harmonics are discussed. In addition, sound pressure de-pendences of the subharmonics and ultraharmonics are studied in theory as well as in measurement. Results reveal that the developments of both subharmonics and ultrahar-monics have the same trend, i.e. occurrence, growth and saturation, but the generation of ultraharmonic is a little earlier than that of subharmonic.Subbarmonics or ultraharmonics provides better contrast-to-tissue ratio （CTR） than the fundamental or the second harmonics, having prospective application in medical diagnosis. In this paper, subharmonic and ultraharmonic emissions are theoretically studied through nonlinear oscillation of encapsulated bubbles. The optimized frequencies for emissions of the subharmonics and ultraharmonics are discussed. In addition, sound pressure dependences of the subharmonics and ultraharmonics are studied in theory as well as in measurement. Results reveal that the developments of both subharmonics and ultraharmonics have the same trend, i.e. occurrence, growth and saturation, but the generation of ultraharmonic is a little earlier than that of subharmonic.

关 键 词：分频谐波 非线性振动 超频率音响 超谐波 UCA 

分 类 号：TN912[电子电信—通信与信息系统]