Numerical consideration of the relationship between nonlinear response and shell parameter of microbubble with coated membrane shell

The nonlinear response of the microbubble ultrasound contrast agent with a coaled membrane shell is studied in this paper for development of a harmonic imaging system, which is used to detect the harmonic components included in the waves scattered from microbubbles. The effect of the shell parameters, dominating the mechanical characteristics of the coating membrane, on the nonlinear response is considered numerically in this study. It is shown that a greater shell elasticity parameter S_p causes an increase in the resonant frequency of a microbubble. However, a greater shell friction parameter S_f causes only a slight decrease in the resonant frequency. It is also shown that an increase in the shell elasticity and friction parameters S_p and S_f causes a decrease in the harmonic component excitation efficiency.