【Title】 The focus steering for high intensity focused ultrasound phased array based on real-time phase shift calculation

【Author】 WANG Junlin~(1,2) WANG Xiaodong~1 XIAO Ling~1 (1 Medical Acoustics Laboratory, Institute of Acoustics, Chinese Academy of Sciences Beijing 100190) (2 Graduate School of the Chinese Academy of Sciences Beijing 100190)

【Abstract】 When time reversal technique is used in phased array high intensity focused ultrasound system to obtain self-adaptive focusing, it is needed to calculate the initial phases of the elements. Because of the frequency oscillation when the phase lock loop is initiated, different results are got in different segments using conventional methods. A method of calculating the phase difference was presented, that can display the changes of phase difference in real-time, and the steady phase differences can be regarded as the initial phases of the elements. The experimental results show that using the phase difference obtained by this method can get a better distribution of sound field in a certain spatial region.