A System Of Higher Speed Data Acquisition And Detection For Velocity Of Blood Based On Linear CCD

Clinical research reveals that hemorheology parameter has strong inter-relationship with cardiovascular, artery, and hematic disease, therefore, it is a very important reference in medical research and clinical diagnose.The blood viscosity, regarded as the one of the most important hemorheology parameters, reflects the transporting and supplying condition of the blood and influences the flowing of the blood in the body. It can be seen that the velocity of blood is slower when the blood viscosity is low; whereas, the velocity of blood is faster when the blood viscosity is high. Consequently, it has the important meaning to reflect blood viscosity by measuring the velocity of the blood in the case of constant pressure.Charge Coupled Devices(CCD) is a photoelectric device with high performance, which is widely applied in many areas, including astronomical imagine, entertrainment and manufacturing, etc. The geometrical measure with CCD has an advantage on achieving high accuracy, dynamic detection and non-contact measurement. Therefore, the paper introduces a method of real-time measuring the velocity of blood in the use of TCD1702C image sensor.The focus of this dissertation research is to develop the hardware of linear-CCD data acquisition system based on PIC processor, and the related software to support the system. The principle of linear CCD and the scheme of whole system are introduced firstly in the dissertation. The system comprises three modules: the first is the CCD drive module, which is controlled with CPLD. Programming the CPLD to produce CCD drive pluses and synchronized communication signals. The second is data acquisition module. After preprocessing, when detecting the velocity of a drop of blood in the capillary glass,the output video signals of CCD are transmitted into high resolution ADC module, in which they are converted into digital signals and the useful digital signals is memorized by FIFO, and when detecting the velocity of continunous drops of blood in the capillary glass, the thresholding signal is produced by the comparator circuit and it leads that the useful pixel signal is captured by capture module of PIC singal-chip processor. The third is data processing and displaying. The data is processed in PIC singal-chip processor, and the velocity of blood is caculated, and then the data is transported into PC by serial communication. The interface graph is designed in the use of Visual Basic 6.0 software and the curve of the velocity of blood is showed. Finally, the debug process of the unit circuit is introduced in proper sequence. Compiling and silulating the system operation software. The experiment results are presented and analyzed.