心脑血管血流动力学研究对阐明心脑血管的病因以及诊治均起到一定的指导作用，因此血流信号的采集和分析是十分重要的。多普勒超声是目前能够无创、简便、有效提供心脑血管血流动力学资料的最新技术，为此，设计了一套采集系统，将多普勒超声频谱图像提取出来，通过对打印机输出数据格式的分析研究，将其转换为人们熟悉的图形文件格式，再利用计算机图像处理技术，获取血流信号的时间序列数据，使得获取的数据适合各种非线性分析要求。实际算例表明，该系统可靠，能够比较准确地获取血流信号的时间序列数据，为心脑血管疾病的进一步研究提供帮助。

The research on the cardiovascular and cerebrovascular hemodynamics can help to interpret the cause of disease and diagnoses of the cardiovascular and cerebrovascular disease. It is important to collect and analyze the blood flow activity. Now Doppler Ultrasound is the newest technique to supply the data of the cardiovascular and cerebrovascular hemodynamics non-invasively, simply and effectively. In this paper, a digital system was designed. It can get the frequency spectrum image of Doppler Ultrasound's activities. Through the analysis and research on the output data format of a printer, the frequency spectrum image will be stored by the familiar format of image files. With the image manipulation technique, the time series data of the blood flow activity can be obtained and they are fit for various nonlinear analysis. By the system the original blood flow activity can be observed, and the changes of the data in the experiments can also be detected real-timely. It is proved by actual examples that this system is feasible, and the time series data of the blood flow activity obtained are exactly. It can offer assistance for the further study of the cardiovascular and cerebrovascular disease. It can also provide the foundation for uniting nonlinear science and ultrasonic diagnosis in medicine.