病毒磁弛豫检测快速关断电路设计与仿真研究

Design and Simulation of Fast Turn-off Circuit for Virus Magnetorelaxometry

标记小病毒的磁纳米粒子弛豫时间达到微秒甚至纳米量级,病毒磁弛豫检测(MRX)电路关断时间会严重影响小病毒或者蛋白的精确测量。以亥姆赫兹线圈磁场发生装置作为研究切入点,发现传统关断电路在电压切断后,电路中仍然存在若干周期电压震荡干扰源,严重影响MRX电路快速关断时间,基于此提出了一种双闭环快速关断电路,有效解决传统电路存在周期电压震荡干扰难题,大幅提高基于亥姆霍兹线圈的磁测量系统的动态响应上限。仿真实验验证亥姆霍兹线圈励磁系统的关断时间快于30ns,标记小病毒的磁纳米粒子粒径下限约为11nm。

The relaxation time of magnetic nanoparticles labeled with small viruses can reach the magnitude of microseconds or even nanometers,the turn-off time of magnetic relaxation detection(MRX)circuit will seriously affect the accurate measurement of small viruses or proteins.Based on the helmholtz coil magnetic field generator as the research point,the research found that there are still several cycle voltagenoisewhen MRX circuit turn off,and reported a fast turn-off circuit using a double closed-loop circuit,effectively solvedthe problem in the traditional circuit.The upper limit of dynamic response of magnetic measurement system based on Helmholtz coil is greatly improved by using improved fast turn-off circuit.The simulation results show that the turn-off time of the Helmholtz coil excitation system is faster than 30ns,and the particle size limit of the magnetic nanoparticles labeled with small virus is about 11nm.