编码超声血流多深度检测
Multi-depth blood flow detection based on coding ultrasound technique

血流信息检测及其成像因其独特的优势，在临床上得到广泛应用。但常规经颅多普勒超声系统仍采用模拟和数字电路结合的传统技术，这类系统容易受到外界干扰且不能进行多深度检测。文章设计出一种全数字多普勒超声血流检测系统方案，弥补了传统模拟系统存在的问题。多普勒仿体和人体实验结果表明，该系统能够进行多深度检测，确定血管的深度；同时，还提高了检测灵敏度、超声穿透力和系统成像分辨率。
Blood flow measurement and imaging are important branches in ultrasound diagnostic system. Because of its unique advantages, it has been widely used in clinical departments. However, conventional Transcranial Doppler (TCD) ultrasound system in domestic markets still uses the traditional technology combined with analog and digital circuits. Such instruments are susceptible to external changes and cannot offer a multi-depth examination. In this study, a multi-depth digital design of TCD ultrasound system is introduced, which can make up for the deficiency of the traditional analog system to achieve a multi-depth inspection and to enhance the detection sensitivity, the average penetration capacity and resolution of the system. The feasibility of the system is proved by the phantom test, pump and clinical experiments. All of the results show that the system could display the blood flow information on the path of the ultrasound wave, detect the vessel positioning. Meanwhile, it also can greatly improve the measurement sensitivity.