数字化多深度脉冲波超声多普勒系统的设计与实验研究

Design and experimental study of a digital multigated PW ultrasound Doppler system

目的设计一套数字化脉冲波超声多普勒系统,以实现多深度血流频谱分析和显示。方法首先开发了一块PCI接口的数据采集卡,用于采集正交模拟解调后的超声回波信号,然后在PC平台上对数据进行了累加、壁滤波、谱分析等分析处理。结果导管水流测量和人体血流测量两组实验结果验证了算法的正确性,表明在正交模拟解调后对数据进行模数转换,利用数字信号处理的手段对数据分析处理,完全可以替代传统系统中模拟电路构成的距离选通、积分、采样保持和壁滤波等环节。结论相对于传统的模拟血流测量装置,本系统在稳定性和可移植性方面更具有优势,不仅可方便实现多深度的谱分析和显示,还可扩充更多功能。

Objective To design a digital multigated PW ultrasound Doppler system and validate the system in experimental study. Methods A data gathering card for PCI bus interface is developed to sample the demodulated signals. Through PCI bus, all data is transferred to PC system, in which further processing is carried out and final results are displayed. Resuits Results from a simulated blood flow measurement system and a human blood flow measurement experiment are provided. The analog circuits in conventional system, such as range gating, integrator, sample-hold, wall filter, are replaced by digital signal processing methods. Conclusion Compared to the conventional analog blood flow detection devices, the proposed system is more stable and flexible. Multigated functions are successfully realized in the system.