编码激励超声多普勒系统分辨率性能分析

Resolution analysis of fully digital ultrasound Doppler system using coded excitation

对于传统经颅多普勒检测设备,由于其采用大规模模拟电路,因此会使得整个系统的体积大,功耗高。而且模拟器件的不稳定性也会导致整个系统灵敏度低,准确性差,同时也会使得血流深度信息提取不足,以及系统信噪比较低。设计出了一种结合编码激励技术的全数字编码激励经颅多普勒系统,使得血流检测系统体积变小,而且能够获得更好的分辨率和灵敏度。以检测两条上下并行紧贴血管仿体实验为例。在实验中,采用4周期基础码调制的11位Barker码编码激励方式,通过介绍全数字编码激励经颅多普勒系统实现方法,并与传统商用经颅多普勒系统实验结果进行对比分析,证明了全数字编码激励经颅多普勒系统具有更好的分辨率。

Traditional Doppler ultrasound system, which had a large-scale analog circuit,, could result in a large volume and consume too much power consumption of the entire system. What＇s more, the cause of the instability of analog circuits is ascribe to the application of large-scale analog circuit. Eventually, it was made the system in a low sensitivity, poor accuracy, limited depth information and low SNR by those reasons. In this paper, a digital ultrasound Doppler system using coded excitation was designed. The digital design of ultrasound system has many advantages, such as a higher sensitivity and a better resolution. It was based on the experiment of detecting two close blood vessels, that the 4-cycle base ll-chip Barker coded excitation was used in this study. By introducing the methods of full digital design of TCD and comparing the experimental results of the traditional TCD, it could prove that coded system had a better resolution.