The Design And Implementation Of A Multi-channel Magnetic Resonance Imaging Signal Acquisition And Processing Platform Based On FPGA

Magnetic resonance imaging technology is widely used in biomedical imaging due to its safety,non-invasiveness,and non-radiation.The acquisition and processing of imaging signals is a vital part of a magnetic resonance spectrometer.Its performance will directly affect the quality of the obtained images.In this field,China has a large market demand and a high dependence on imports.Therefore,it is of great significance to design a high-performance magnetic resonance imaging signal acquisition and processing platform with independent intellectual property rights.Based on the application scenario and the demands of partners,a set of acquisition and processing platform for 1.5T magnetic resonance imaging signals is designed.The platform includes analog signal acquisition and preprocessing,digital signal processing and data transmission.Among them,the analog acquisition and preprocessing module can achieve 63 dB dynamic amplitude adjustment of the input signal and complete the analog-to-digital conversion with 16-bit resolution;the digital signal processing module can implement signal processing algorithms based on FPGA and the local storage of data;the transmission module includes a 10 Gigabit Ethernet optical interface with a maximum effective data rate of 10 Gbps and a PCIe interface with a maximum effective data rate of 32 Gbps,which can both be used for high-speed communication with a PC.The hardware platform of this system is an independently designed ten-layer printed circuit board,containing both analog circuits and digital circuits.The board includes 1,306 components and 3,839 signal nets.During the design process,with the help of theoretical calculations and simulations,signal integrity challenges(including high-speed signal routing up to 10.3125Gbps),power integrity challenges(including the design of 10 voltages,14 power supplies and 50 power supply networks),and electromagnetic compatibility challenges(including mutual interference between digital and analog circuits)are all solved.Based on the hardware platform,a set of magnetic resonance imaging signal processing software is designed and implemented independently,involving data interaction across multiple platforms.It includes FPGA programming to implement signal processing algorithms and the control of peripherals,MCU programming for local interactive interface design,and host computer programming for remote interactive interface design,data visualization,and PCIe driver implementation.The original intention of the designed signal acquisition and processing platform is to apply to 1.5T magnetic resonance spectrometer.However,facing devices with other magnetic induction intensity,it can also be used with a small number of parameter modifications and chip replacement.In addition,the software defined radio ideas shown in the design can be used for reference to the related designs in the fields of medical ultrasound imaging,terahertz imaging,and radar signal processing.Therefore,it has some social significance.