School of Electronics and Information Engineering, Xi'an Jiaotong University, Xi'an 710000, China.
International College, Hunan University of Arts and Sciences, Changde 415000, China.
Comput Math Methods Med. 2020 May 27;2020:9812019. doi: 10.1155/2020/9812019. eCollection 2020.
In this paper, we present a parallel framework based on MPI for a large dataset to extract power spectrum features of EEG signals so as to improve the speed of brain signal processing. At present, the Welch method has been wildly used to estimate the power spectrum. However, the traditional Welch method takes a lot of time especially for the large dataset. In view of this, we added the MPI into the traditional Welch method and developed it into a reusable master-slave parallel framework. As long as the EEG data of any format are converted into the text file of a specified format, the power spectrum features can be extracted quickly by this parallel framework. In the proposed parallel framework, the EEG signals recorded by a channel are divided into overlapping data segments. Then, the PSD of segments are computed by some nodes in parallel. The results are collected and summarized by the master node. The final PSD results of each channel are saved in the text file, which can be read and analyzed by Microsoft Excel. This framework can be implemented not only on the clusters but also on the desktop computer. In the experiment, we deploy this framework on a desktop computer with a 4-core Intel CPU. It took only a few minutes to extract the power spectrum features from the 2.85 GB EEG dataset, seven times faster than using Python. This framework makes it easy for users, who do not have any parallel programming experience in constructing the parallel algorithms to extract the EEG power spectrum.
在本文中,我们提出了一个基于 MPI 的并行框架,用于处理大型数据集,以提取 EEG 信号的功率谱特征,从而提高脑信号处理的速度。目前,Welch 方法已被广泛用于估计功率谱。然而,传统的 Welch 方法需要大量的时间,尤其是对于大型数据集。针对这一问题,我们将 MPI 引入到传统的 Welch 方法中,并将其开发成一个可重用的主从式并行框架。只要将任何格式的 EEG 数据转换为指定格式的文本文件,就可以通过这个并行框架快速提取功率谱特征。在提出的并行框架中,将记录的单通道 EEG 信号划分为重叠的数据段。然后,通过一些节点并行计算分段的 PSD。主节点收集并汇总结果。最后,将每个通道的最终 PSD 结果保存在文本文件中,该文件可以用 Microsoft Excel 读取和分析。这个框架不仅可以在集群上实现,也可以在桌面计算机上实现。在实验中,我们在一台具有 4 核 Intel CPU 的台式计算机上部署了这个框架。它只花了几分钟的时间就从 2.85GB 的 EEG 数据集提取了功率谱特征,速度比使用 Python 快了七倍。这个框架使用户无需具备任何并行编程经验就可以轻松地构建并行算法来提取 EEG 功率谱。