Short-time Fourier Transform of Free Induction Decays for the Analysis of Serum Using Proton Nuclear Magnetic Resonance
Short-time Fourier Transform of Free Induction Decays for the Analysis of Serum Using Proton Nuclear Magnetic Resonance
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DOI：
10.5650/jos.ess18212
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发表时间：
2019-01-01
影响因子：
1.5
通讯作者：
Ohno, Youkichi
中科院分区：
文献类型：
--
作者：
Hirakawa, Keiko;Koike, Kaoru;Ohno, Youkichi
质子核磁共振（NMR）是有用的分析生物样品，如血清。自由感应衰减（FIDs）是一种核磁共振信号，它跟随施加在共振频率上的射频脉冲。短时傅里叶变换（STFT）是时频分析的基本方法。本研究的目的是确定FIDs的STFT是否能够灵敏地检测血清特性的变化和差异。FIDs从年龄为65岁的年轻健康男性志愿者的血清中获得。时域分析采用瞬时幅值的时域变化，频域分析采用快速傅立叶变换，时域傅里叶变换。基于stft的频谱图代表了随时间动态变化的复频率成分，表明该频谱图能够可视化FID的特征。此外，偏最小二乘判别分析的结果表明，STFT在区分年轻和老年受试者血清方面优于其他两种方法。总之，质子核磁共振测量获得的FIDs的STFT可用于评估从血清样品获得的FIDs的相似性和差异性。
Proton nuclear magnetic resonance (NMR) is useful for the analysis of biological samples such as serum. Free induction decays (FIDs) are NMR signals that follow a radio-frequency pulse applied at the resonance frequency. Short-time Fourier transform (STFT) is a basic method for time-frequency analyses. The purpose of this study was to ascertain whether the STFT of FIDs enables the sensitive detection of changes and differences in serum properties. FIDs were obtained from serum collected from young, healthy, male volunteers = 65 years of age. Temporal changes in the instantaneous amplitudes for the time-domain analysis, fast Fourier transform for frequency-domain analysis, and STFT were applied to the FIDs. The STFT-based spectrogram represented the complex frequency components that changed dynamically over time, indicating that the spectrogram enabled the visualization of the features of an FID. Furthermore, the results of a partial least-squares discriminant analysis demonstrated that the STFT was superior to the other two methods for discriminating between serum from younger and older subjects. In conclusion, the STFT of FIDs obtained from proton NMR measurements was useful for evaluating similarities and dissimilarities in the FIDs obtained from serum samples.