The estimation of the second harmonic with differential concentration microbubbles
Date Issued
2007
Date
2007
Author(s)
Chuang, Chih-Yang
DOI
zh-TW
Abstract
Although the behavior of a bubble in an acoustic field has been studied for a long time, few theoretical describe the simulation of a real population of variably sized micro bubbles in a finite beam. In this thesis, we use the modified Rayleigh-Plesset equation to simulation each single bubble’s oscillator under the different acoustic pressure, and summation all the radiation signals from large number of such bubbles. Consider the effect from the waveform beam. Finally we will compare with the experience results. The nonlinear response (second harmonic , sub harmonic) come from the micro bubbles provide an easy way to separate from bubbles and tissue. We would like to use this identity to build up an ultrasound drug deliver system. We use the liposome as the ultrasound contrast agents for the drug carrier, furthermore trying to find the best region to manipulate the variations of liposome concentration and the amplitude of received spectrum. In conclusion, we wish that we could infer the amount of liposome by the amplitude of harmonic in this area, then we could not only to monitor, but also to forecast the amount of the drug carries.
We set each parameter of the contrast agents, and choose the best model、input pulse waveform for the experience environment. We measure the micro bubble’s size distribution by N4-plus coulter and consider the probe effect made different acoustic pressure. We discuss the monitor range when input cycle number 15、20、25. Through experimentation result, we know that all the feasible manipulate areas occur in lower concentrations. We glad to see it, because all the clinical application are under the lower concentration.
Subjects
微氣泡
濃度
microbubbles
concentration
Type
thesis