基于MVT的多通道闪烁脉冲数字化系统的设计与实现

发布时间：2018-11-19 07:13

【摘要】：正电子发射断层成像(Positron Emission Tomograhy,PET)作为核医学领域顶尖的造影技术,被广泛的应用于多种疾病的诊断、疗效评价、脏器功能研究和新药开发等方面,在临床医学和科学研究中发挥着重要的作用。近年来,随着PET闪烁探测器以及闪烁脉冲数字化技术的不断发展,许多全新的PET系统架构相继被推出,引起了研究人员的广泛关注。其中,基于全数字电路架构的新型数字PET探测器的出现为数字PET的问世创造了条件。而以新型LYSO/SiPM闪烁探测器为代表的探测器技术则为实现超高性能的TOF-PET系统搭建以及PET与MRI融合开展多模医学成像研究奠定了基础。众多的数据通道一直是PET成像系统所面临的问题,其中基于SiPM的新型PET系统尤其突显。本文针对这一问题并结合新的闪烁脉冲数字化技术-多电压阈值采样方法(Multi-Voltage Threshold,MVT)设计和实现了多通道闪烁脉冲数字化系统,为基于SiPM的闪烁探测器信号读出提供了解决方案。本文首先通过建立仿真数据库对MVT方法实现SiPM闪烁脉冲数字化进行了系统性的研究。在仿真的基础上,通过改进经典MVT采样电路,提出了电路结构更为紧凑、便于大规模集成的FPGA-Only MVT采样电路并对其性能进行了评估。在此基础上,设计和实现了48通道闪烁脉冲数字化系统,并从功耗、死时间以及闪烁脉冲数字化性能等方面进行了全面评估。最后,本文围绕多通道MVT闪烁脉冲数字化采样电路的系统集成、升级、性能优化展开了深入而全面的研究和讨论。
[Abstract]:Positron emission tomography (Positron Emission Tomograhy,PET) is one of the leading imaging techniques in nuclear medicine, and has been widely used in the diagnosis of many diseases, evaluation of efficacy, organ function research and the development of new drugs. It plays an important role in clinical medicine and scientific research. In recent years, with the continuous development of PET scintillation detector and scintillation pulse digitization technology, many new PET system architectures have been launched one after another, which has attracted wide attention of researchers. Among them, the emergence of a new digital PET detector based on full digital circuit architecture creates conditions for the advent of digital PET. The new type of LYSO/SiPM scintillation detector is the basis for the establishment of ultra-high performance TOF-PET system and the fusion of PET and MRI for multimode medical imaging. Many data channels are always the problem of PET imaging system, especially the new PET system based on SiPM. In this paper, a multi-channel digital system of scintillation pulse is designed and implemented by combining with a new digital technique of scintillation pulse (Multi-Voltage Threshold,MVT). It provides a solution for signal readout of scintillation detector based on SiPM. In this paper, the systematic research on the realization of SiPM flicker pulse digitization by MVT method is carried out by establishing the simulation database. On the basis of simulation, by improving the classical MVT sampling circuit, a FPGA-Only MVT sampling circuit which is more compact and convenient for large-scale integration is proposed and its performance is evaluated. On this basis, the 48 channel flash pulse digitization system is designed and implemented, and the power consumption, dead time and digital performance of the flash pulse are comprehensively evaluated. Finally, the system integration, upgrade and performance optimization of multi-channel MVT scintillation pulse digital sampling circuit are studied and discussed thoroughly in this paper.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TH789

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