高分辨核磁共振实验与数据处理的自动化关键技术研究
发布时间：2018-11-22 11:21
【摘要】：自1945年核磁共振(Nuclear Magnetic Resonance, NMR)现象被发现以来,核磁共振技术的发展犹如一棵常青树,目前已经成为应用最为广泛的分析技术之一。核磁共振技术之所以能具有如此强大的生命力主要是由于其能提供大量的化学结构信息和动力学信息,而高分辨率的谱图正是提供这些信息的基础。随着核磁共振在代谢组学等领域的不断发展应用,如何自动地获得高分辨率的核磁共振谱图越来越受到人们的重视,这也是核磁共振波谱仪研发的一个重要挑战和机遇。 本论文从实验和数据处理两个方面,开展自动获取高分辨核磁共振谱图的研究工作。在具有自主知识产权的核磁共振波谱仪上,实现了自动获取高分辨核磁共振谱图所需的三项关键技术：自动匀场方法,自动相位校正方法以及自动基线校正方法,并在此基础上提出了一些更优化的改进方案。 在自动化核磁共振实验的研究工作中,我们针对高分辨核磁共振实验必须具备的前提条件之一——均匀的静磁场展开研究。在自主开发的核磁共振波波谱仪中实现了各种自动匀场方法包括基于搜索算法的自动匀场方法,一维和三维梯度匀场方法,及结合线形的梯度匀场方法。并在此基础上,提出了一些改进方法,如：在三维梯度匀场方法中,采用了改进的脉冲序列,使得谱仪可以利用XY匀场线圈来产生相位编码梯度,从而实现了在普通探头上的三维梯度匀场；此外,针对梯度匀场中匀场电流值越界和三维梯度匀场时间过长的两个问题,分别提出了相应的解决方案。 在自动数据处理方面,我们首先实现了核磁共振数据处理软件中的常规算法,并在此基础上发展了若干改进方法,包括一种适用性和准确性都非常高的自动相位校正方法,以及可以适用于基线失真较大谱图的自动基线校正方法。新的自动相位校正方法采用了粗调和细调相结合的方案,在粗调过程中利用了“基线-谱峰”分界点差异最小化的方法获得一个大致准确的校正结果,基于这个结果判断出各个谱峰的特性,即将谱图中的谱峰区分为正峰、负峰和畸变峰。然后利用最小化自定义的负值惩罚函数进行细调,从而获得更准确的自动相位校正结果。最后,通过实验验证出新的自动相位校正方法不仅适用于各种NMR谱图,而且几乎不受信噪比、基线失真等因素的影响。表明此方法不仅普适性强,而且具有很好的鲁棒性以及准确性。新的自动基线校正方法的基础是改进的基线识别算法和迭代的基线模型构建算法。其中,改进的基线识别算法不仅结合了三种常用的基线识别算法,而且还利用谱峰轮廓拟合的方法来准确地识别出谱图中的宽峰信号。而在迭代的基线模型构建算法中,我们不仅利用了识别出的基线区间,还在迭代的过程中自动地寻出谱图中谱峰重叠非常严重区间中的“准基线点”,利用这些“准基线点”我们可以构建出更符合实际情况的基线模型,从而得到更好的基线校正结果。实验证明这种新的自动基线校正方法能够更有效地处理谱峰密集和基线失真严重的复杂NMR谱图。
[Abstract]:Nuclear magnetic resonance (NMR) has been developed as a evergreen tree since the nuclear magnetic resonance (NMR) phenomenon in 1945, and has become one of the most widely used analytical techniques. The nuclear magnetic resonance technology can have such strong vitality mainly because it can provide a large amount of chemical structure information and kinetic information, and the high-resolution spectrogram is the basis for providing these information. With the development of nuclear magnetic resonance in the field of metabolism, how to obtain the high-resolution NMR spectrum is more and more important, which is also an important challenge and opportunity for the R & D of the nuclear magnetic resonance spectrometer. In this paper, from the aspects of experiment and data processing, an automatic acquisition of the high-resolution nuclear magnetic resonance spectrum is carried out. The three key technologies required for automatic acquisition of high-resolution nuclear magnetic resonance (NMR) spectrum are realized on a nuclear magnetic resonance spectrometer with independent intellectual property rights: an automatic uniform field method, an automatic phase correction method, and an automatic base line correction. Methods, and on the basis of this, some more optimization improvements are put forward Protocol. In the study of automated nuclear magnetic resonance experiments, we have one of the prerequisites for high-resolution nuclear magnetic resonance experiments _ a uniform static magnetic field The field development research has been carried out in the self-developed nuclear magnetic resonance wave spectrometer, which comprises the following steps: an automatic uniform field method based on a search algorithm, a three-dimensional gradient uniform field method for peacekeeping, and a linear ladder in that method of three-dimensional gradient uniform field, an improved pulse sequence is used, so that the spectrometer can use the XY uniform field coil to generate the phase encode gradient, so that the three-dimensional gradient on a common probe is realized, in addition, that problem that the uniform field current value of the gradient uniform field and the time of the three-dimensional gradient uniform field are too long are put forward. In the aspect of automatic data processing, we first realized the conventional algorithm in the nuclear magnetic resonance data processing software, and on the basis of this, we developed a number of improved methods, including a very high degree of applicability and accuracy. Automatic phase correction method, and can be applied to a baseline distortion larger spectrum map The new automatic phase correction method adopts the scheme of coarse and fine phase modulation and fine phase modulation. In the coarse tuning process, the method of minimizing the difference of the 鈥渂aseline-spectrum peak鈥，
本文编号：2349206
[Abstract]:Nuclear magnetic resonance (NMR) has been developed as a evergreen tree since the nuclear magnetic resonance (NMR) phenomenon in 1945, and has become one of the most widely used analytical techniques. The nuclear magnetic resonance technology can have such strong vitality mainly because it can provide a large amount of chemical structure information and kinetic information, and the high-resolution spectrogram is the basis for providing these information. With the development of nuclear magnetic resonance in the field of metabolism, how to obtain the high-resolution NMR spectrum is more and more important, which is also an important challenge and opportunity for the R & D of the nuclear magnetic resonance spectrometer. In this paper, from the aspects of experiment and data processing, an automatic acquisition of the high-resolution nuclear magnetic resonance spectrum is carried out. The three key technologies required for automatic acquisition of high-resolution nuclear magnetic resonance (NMR) spectrum are realized on a nuclear magnetic resonance spectrometer with independent intellectual property rights: an automatic uniform field method, an automatic phase correction method, and an automatic base line correction. Methods, and on the basis of this, some more optimization improvements are put forward Protocol. In the study of automated nuclear magnetic resonance experiments, we have one of the prerequisites for high-resolution nuclear magnetic resonance experiments _ a uniform static magnetic field The field development research has been carried out in the self-developed nuclear magnetic resonance wave spectrometer, which comprises the following steps: an automatic uniform field method based on a search algorithm, a three-dimensional gradient uniform field method for peacekeeping, and a linear ladder in that method of three-dimensional gradient uniform field, an improved pulse sequence is used, so that the spectrometer can use the XY uniform field coil to generate the phase encode gradient, so that the three-dimensional gradient on a common probe is realized, in addition, that problem that the uniform field current value of the gradient uniform field and the time of the three-dimensional gradient uniform field are too long are put forward. In the aspect of automatic data processing, we first realized the conventional algorithm in the nuclear magnetic resonance data processing software, and on the basis of this, we developed a number of improved methods, including a very high degree of applicability and accuracy. Automatic phase correction method, and can be applied to a baseline distortion larger spectrum map The new automatic phase correction method adopts the scheme of coarse and fine phase modulation and fine phase modulation. In the coarse tuning process, the method of minimizing the difference of the 鈥渂aseline-spectrum peak鈥，
本文编号：2349206
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