基于CMOS技术的多通道TOF-PET脉冲时间信息数字化单芯片系统研究

CMOS based pulse digital processing is the most feasible solution for all digital TOF-PET imaging system. High-speed precise digitization of timing information is the key aspect to improve image quality. Considering the rising/fading edge of the scintillation pulses is in the range of nano-second, traditional complex digitization methods involving pulse shaping and ADC sampling limit the timing and reduce image quality. Based on accurate acquisition of timing information, Multi-threshold voltage (MVT) method employs a simple, non-ADC architecture, which directly extracts timing and energy information of the scintillation-pulses with very high resolution. This project will focus on CMOS based MVT solutions for the direct-digitization of the timing information of the TOF-PET pulses. Pico-second accuracy trigger method, high resolution timing information digitization and system offset self-calibration will be studied in detail. This project will also explore the scheme for constructing a high timing resolution integrated system of TOF-PET scintillation-pulse digital processing. Research findings can serve as the basis to realize a very large scale multichannel TOF-PET pulses digital processing system. It can not only further improve the image quality of TOF-PET system, but also contributes to the developing of PET medical imageology in biological science and clinical studies.

基于CMOS技术的脉冲数字处理系统是全数字TOF- PET最有潜力的方案。精确获取脉冲时间信息是提高成像质量的关键。闪烁脉冲上升/衰减时间仅为纳秒量级，先整形再经ADC的处理方式结构复杂,限制了皮秒量级时间信息的精确获取，制约了成像质量。 基于精确测量脉冲时间信息的多电压阈值法（MVT）不使用ADC，系统架构大幅简化，直接处理脉冲就可获得优异的时间和能量信息。本项目研究基于CMOS技术采用MVT方法精确获取TOF-PET脉冲时间信息的方案，解决其中皮秒级精确触发、时间信息高分辨率数字化及系统自校准等关键问题，探索基于CMOS技术实现多通道TOF-PET脉冲时间信息数字化单芯片系统的方案。 研究成果可以为实现多通道TOF-PET脉冲大规模集成全数字处理系统奠定方法和技术基础，进一步提高TOF-PET的成像分辨率，推动生命科学和临床医学中PET成像技术的发展。

精确获取闪烁脉冲时间信息是全数字TOF- PET提高成像质量的关键。闪烁脉冲上升/衰减时间仅为纳秒量级，先整形再经ADC数字化的方案会造成脉冲时间信息丢失，限制了皮秒量级时间信息的精确获取，降低了成像质量。本项目研究基于CMOS技术采用多电压阈值精确获取TOF-PET脉冲时间信息的方法，探索基于CMOS技术设计多通道TOF-PET脉冲时间信息精确数字化芯片的方案。.. 本项目深入研究了闪烁脉冲皮秒级精确触发、高精度数字化时间信息测量和系统自校准等关键问题，设计了宽频高速数字比较器，解决了随机高速闪烁脉冲的高精度捕获问题，构造了自校准两级DLL精确测时系统，掌握了基于CMOS直接数字化闪烁脉冲的核心技术。结合比较器和精确测试系统，设计了多通道高精度TOF-PET时间信息数字化芯片并成功流片，时间分辨率优于30 ps，为多通道TOF-PET脉冲大规模集成全数字处理系统奠定了设计方法和核心硬件基础。.. 通过本项目的工作发表论文15篇，申请中国发明专利6项，获得中国发明专利授权2项，获得集成电路布图设计登记证书7项。本项目的工作是全数字TOF-PET成像系统的核心共性技术，为进一步提高TOF-PET的成像分辨率和推动PET成像技术的发展奠定了坚实的基础