Study Of Multi-slice Spiral CT Detection And Data Acquisition System

CT (Computed Tomography) detection is an important Non-Destructive testing method. It has been widely used in aerospace, aviation, casting, security inspection, medical and other fields. With the domestic and the international situation changes, the anti-terrorism and transportation security issue have become increasingly important. Airport, railway station and other public places security checks have become increasingly demanding. The security equipments that currently used in airports, railway stations are based on the method of transmission imaging. They do not meet the safety requirements anymore. For example, use the traditional security equipments, we can't identify the materials in a complex background, can't measure the density of the object, and can't make sure its atomic number. Moreover, we can't distinguish the shape and texture of the objects in the package. There has been a growing interest to improve the security inspection equipments which can quickly and accurately detect whether the package contain contraband or explosive. Therefore, security inspection equipments that use CT technology are the future development trend.This paper focuses on the multi-slice spiral CT in detection and data acquisition system. Data acquisition system is an important part of the CT system. It requires a stable and reliable data- collecting to guarantee the quality of the reconstructed image. Modularization and layered design idea are used in this paper. The large-scale, multi-channel data acquisition system is divided into several small pieces. In this paper, DAS is composed of signal detection layer, data acquisition layer and data transfer layer. Such modular design allows the system to have greatly expansibility. It can simply increase the number of the modules to complete the expansion of the system which avoids the re-design the system, thus greatly reducing the workload of the design. In the preliminary practice, we found that such scheme is feasible. With further improvement, it is believed that this structure of the data acquisition system applied in multi-slice CT data collection is very promising.The main work of this project includes two parts: printed circuit board design and software design. The printed circuit board design primarily use the PROTEL software. And use the Quartus II SDK to compiler, synthesis, simulation the software design. The FPGA EP1C3T144 which produced by ALTERA company is used as controller in the design. Using the chip DDC232 produced by TI as the signal amplifier and analog-digital converter.