Accurate Detection Method Of Relaxation Signals And Its Applications In Low Field Nuclear Magnetic Resonance

In low-field nuclear magnetic resonance(NMR),the detection accuracy of relaxation sig-nals decides the quantitative analysis precision of detection targets.To improve the detection accuracy of relaxation signals,there are two primary approaches,by accurately setting acqui-sition parameters and by optimizing key hardware.In view of existed problems in the accurate detection of relaxation signals,some new methods and technical improvements were proposed.Major results are detailed as follows.(1)A software architecture with high portability and scalability was proposed.Based on the low-field NMR platform built by the laboratory,simplified mathematical model and routine analysis was studied for basic relaxation signal of a standard sample,and then the software plat-form was developed.The main innovations of this achievement were the innovative software design for the hardware modules and functional modules,and the innovative analysis methods that suppress the negative effects of noise.(2)Automatic and accurate searching methods for key acquisition parameters,including receiver gain,resonance frequency and pulse width,were proposed.High-precision profiling methods for key hardware characteristics,including magnetic field inhomogeneity of the mag-net,dead time of the probe and signal-to-noise ratio of the whole machine were proposed.The main innovation of this achievement was the great suppress of negative effects in finding basic parameters and hardware profiling by NMR method.(3)Based on the research results,the procedure for accurate detection and analysis of mul-tivariable relaxation signals was proposed.Accurate quantitative analysis of body fat in live mouse and total polar compounds in frying oil was performed respectively on the fully control-lable platform built by the laboratory and the incompletely controllable platform of commercial.The main innovation of this achievement was the proposed innovative combined pulse sequence to achieve higher-precision quantitative analysis of the detection target.In summary,the subject aims at the shortage and existed problems of accurate detection of relaxation signals in low field nuclear magnetic resonance.New methods and improvements were proposed for accurately settling key basic parameters and profiling key hardware charac-teristics by nuclear magnetic resonance methods.The software to acquire and analyze relax-ation signals accurately was developed for low field nuclear magnetic resonance.The proposed methods were carried out on laboratory built and commercial platform.