The FPGA Design of 0.5T Joint MRI System Console

核磁共振成像是目前医学影像中应用最为广泛的新成像技术之一，原理是在磁场中利用线圈发出射频脉冲激发质子发生共振，从而产生磁共振信号，采集并传至计算机进行数据处理最终成像。核磁共振成像技术能够快速、准确获得人体各部位阻值症状信息，具有对比度高、成像参数多、无电离辐射伤害等优点。 磁共振成像仪器主要由主控计算机、控制台、射频功率放大器、梯度功率放大器、射频线圈、梯度线圈、磁体和温控等模块组成。其中，控制台是整个仪器的核心模块，它负责系统中各个模块间的通信、射频脉冲信号和梯度信号的产生、各个外设器件的控制以及信号处理。控制台的技术要求较高，其性能的好坏直接关心到磁共振成像的质量是否达到用户的需求。目...Nowadays, magnetic resonance imaging becomes one of the most widely used imaging techniques in medical imaging. It uses radio frequency (RF) pulses to excite the hydrogen nucleuses in the magnetic field then producing nuclear resonance signals, which are sent to computer to obtain images. It can obtain the information of patients’ internal clinical symptom accurately and rapidly, with the advant...学位：工学硕士院系专业：物理与机电工程学院_工程硕士(电子与通信工程)学号：3312012115267

水痘-带状疱疹病毒糖蛋白gE在昆虫细胞中的表达鉴定及其晶体培养

目的利用杆状病毒-昆虫表达系统建立纯化水痘带状疱疹病毒(VZV)包膜糖蛋白gE的方法,筛选gE蛋白的晶体培养条件,以期用于结构解析。方法将VZV糖蛋白gE基因序列克隆至杆状表达载体pAcgp67B载体中,利用High FiveTM昆虫细胞表达gE蛋白并进行TALON亲和层析纯化;利用WAVE生物波浪反应器建立含硒代甲硫氨酸的gE蛋白方法,以便在晶体结构解析中利用单波长或多波长异常散射进行相位解析;通过分子排阻色谱、分析超离,差示扫描量热法和酶联免疫吸附试验等分析gE蛋白的理化性质;利用结晶试剂盒对gE498和gE354蛋白的结晶条件进行初筛。结果获得的gE498和gE354蛋白纯度约为90%、产量为8～10 mg/L。理化分析显示两种gE蛋白在溶液中主要以均一稳定的单体形式存在,并呈现出良好的反应原性。在gE354晶体初筛中获得3个结晶条件:CrystalH3、PEGH12和IndexB10。结论建立了VZV糖蛋白gE表达和纯化方法,制备的蛋白纯度高,且具有反应原性,并筛选出CrystalH3、PEGH12和IndexB10这3个结晶条件,为gE糖蛋白的结构与功能研究及新型疫苗开发奠定了基础。国家自然科学基金项目(No.81871648);;\n新药创制专项项目(No.2018ZX09711003-005

Design of 0.5T magnetic resonance imaging console based on SOPC

针对磁共振成像仪控制台的数字化、小型化发展趋势,设计了一种0.5T磁共振关节成像仪控制台的总体框架。以FPGA的SOPC(System On the Programmable Chip)系统为仪器控制核心,开发了数字化磁共振成像仪控制台部分,将网络传输、数据处理、射频脉冲及梯度波形产生、外设驱动等各个功能集成在单一FPGA芯片中。实现上位机对输出波形,数字调制解调,梯度涡流补偿,抽取滤波等功能的控制。通过各个模块测试,系统功能稳定、脉冲波形可定制,为小型化磁共振成像仪的控制台研制提供了一种可靠性高而灵活的设计方案。Aiming at the development of the digitalization and miniaturization of the MRI system console,the basic structure and work flow of console for the 0.5T MRI were introduced.The consde is designed based on highly integrated SOPC system of FPGA,network communication,data processing,waveform generating is realized and peripherals in signal FPGA is controlled.Realization of tuning the wave,modulation &demodulation,gradient eddy current compensation,decimation and multiple filtering by PC.Finally the system are tested,results show that the system has the merits of high reliability,flexible pulse sequences,providing a compact and flexible scheme for MRI console.国家自然科学基金(11175149)资助项

Design of NMR receive channel based on STM32

针对核磁共振波谱仪中接收通道的功能需要,提出了一种基于STM32作为协处理器,通过移植lWIP协议栈,实现数据流直接多通道网络传输的设计方案。该方案和以往方案相比,大大减轻了主处理器fPgA的工作负担,并且具有实时性高、模块化、易于拓展等特点。主要介绍了该方案的主要设计思路以及软硬件基本架构,重点阐述了其中的关键技术,实物完成后通过nETIO以及系统联机测试的结果表明本方案满足波谱仪接收通道的实际性能需要,同时使得系统的可维护性得到了提高。To satisfy the require of the receiver channel,this paper puts forward a designing program which uses STM32as a co-processor and LwIP as a protocol stack to achieve multichannel data transmission.Compared to the previous programs,this program greatly reduces the workload of the host processor FPGA,It is high real-time,modular and easy to expand.The paper will introduce the software and hardware platform of this program and the key of techniques.The result based on netio and on-line testing proves that this program meets the requirement of receiver channel and improves the manufacturing and maintainability of the system

Theoretical analysis and numerical calculation of the performance of pulsed liguid jet pump

推导了以往复泵为脉冲发生装置的脉冲液体射流泵准二维性能方程及其时均性能方程,导出无因次惯性水头及惯性力项便于计算的表达式,并对脉冲液体射流泵时均性能进行了数值计算,计算结果与试验数据基本吻合,将数值计算的模拟曲线与恒定液体射流泵性能曲线进行对照,证明了采用脉冲射流作为工作动力能够大幅提高射流泵的效率

脉冲液体射流泵性能的理论分析及数值计算

推导了以往复泵为脉冲发生装置的脉冲液体射流泵准二维性能方程及其时均性能方程，导出无因次惯性水头及惯性力项便于计算的表达式，并对脉冲液体射流泵时均性能进行了数值计算，计算结果与试验数据基本吻合，将数值计算的模拟曲线与恒定液体射流泵性能曲线进行对照，证明了采用脉冲射流作为工作动力能够大幅提高射流泵的效率

Design of MRI communications and pulse generation module

针对小型化核磁共振成像仪主控板的功能需要提出新的设计方式,采用FPGA开发板作为主控板,以Nios II嵌入式软核作为协处理器,通过在其上移植μC/OS-Ⅱ操作系统及lwIP协议栈,实现与计算机的网络通信;使用Verilog硬件描述语言编写脉冲序列生成模块,实现对指令的解析以及执行,形成用户要求的脉冲序列。最终测试结果表明,主控板的通信速率以及通过示波器采集得到的脉冲序列均满足成像仪系统要求。而且这种软硬结合的设计方式与以往全软件的设计相比,使成像仪精度更高,性能更加稳定。To satisfy the require of the MRI main control board,this paper puts forwards a new design which uses FPGA development board as main control board and uses Nios II as a co-processor.We transplant theμC/OS-II operating system and protocol stack lwIP to achieve the network communication with computers.Then we use the hardware language Verilog to write pulse sequence generation module to achieve the analysis and execution of the command.Eventually it produces user's pulse sequence.Final test results show that the communication rate of the main control board and pulse sequence which is obtained by oscilloscope can satisfy the requirements of the MRI system.Compared with the past of the whole software design,this design make the MRI system higher precision and more stable.国家自然科学基金(11175149)资助项