Selection of Spectrogram’s Best Window Size in EMG Signal during Core Lifting Task
Keywords:Best Window Size, Electromyography, Instantaneous RMS Voltage, Lifting Task Spectrogram, TimeFrequency Representation,
AbstractElectromyography (EMG) is one of the most commonly used tools to study human muscle condition. Past researchers have introduced various techniques from time distribution (TD), frequency distribution (FD) and timefrequency distribution (TFD) to extract information from this EMG signal. However, due to the complex characteristics of the EMG signal itself, TFD such as spectrogram has been widely used as it can provide both temporal and spectral information. However, since spectrogram has a fix window size, there exists a dilemma of resolution, where the too narrow window will result in a poor frequency resolution, and a too wide window will cause poor time resolution. Thus, this study aims to select the best window size to be used with spectrogram to monitor human muscle electrical activity during core lifting task. Four electrodes were placed over different types of muscles, which are the right and left biceps branchii (BB), and right and left erector spinae (ES). In this study, six window sizes (64, 128, 256, 512, 1024, and 2048) were used. The test has been done using two evaluating criteria, namely frequency resolution (Fr) and time resolution (Tr). The result shows that both window size of 512 and 1024 are acceptable, but the best window for this application is window size 512.
A. Merlo and I. Campanini, “Technical Aspects of Surface Electromyography for Clinicians,” Open Rehabil. J., vol. 3, pp. 98– 109, 2010.
E. F. Shair, A. R. Abdullah, T. N. S. Tengku Zawawi, S. A. Ahmad, and S. Mohamad Saleh, “Auto-Segmentation Analysis of EMG Signal for Lifting Muscle Contraction Activities,” J. Telecommun. Electron. Comput. Eng., vol. 8, no. 7, pp. 17–22, 2016.
S. Karlsson, J. Yu, and M. Akay, “Time-Frequency Analysis of Myoelectric Signals During Dynamic Contractions: A Comparative Study,” IEEE Trans. Biomed. Eng., vol. 47, no. 2, pp. 228–38, 2000.
I. Yesilyurt, “The Application of the Conditional Moments Analysis to Gearbox Fault Detection - A Comparative Study Using the Spectrogram and Scalogram,” NDT E Int., vol. 37, no. 4, pp. 309–320, 2004.
V. Gnann and M. Spiertz, “Inversion of Short-Time Fourier Transform Magnitude Spectrograms with Adaptive Window Lengths,” in IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP 2009), 2009, pp. 325–328.
R. Merletti, “Standards for Reporting EMG Data,” J. Electromyogr. Kinesiol., vol. 9, no. 1, pp. 1–5, 1999.
B. Zeng, Y. Zhou, Z. Teng, and G. Li, “A Novel Approach for Harmonic Parameters Estimation Under Nonstationary Situations,” Int. J. Electr. Power Energy Syst., vol. 44, no. 1, pp. 930–937, 2013.
How to Cite
TRANSFER OF COPYRIGHT AGREEMENT
The manuscript is herewith submitted for publication in the Journal of Telecommunication, Electronic and Computer Engineering (JTEC). It has not been published before, and it is not under consideration for publication in any other journals. It contains no material that is scandalous, obscene, libelous or otherwise contrary to law. When the manuscript is accepted for publication, I, as the author, hereby agree to transfer to JTEC, all rights including those pertaining to electronic forms and transmissions, under existing copyright laws, except for the following, which the author(s) specifically retain(s):
- All proprietary right other than copyright, such as patent rights
- The right to make further copies of all or part of the published article for my use in classroom teaching
- The right to reuse all or part of this manuscript in a compilation of my own works or in a textbook of which I am the author; and
- The right to make copies of the published work for internal distribution within the institution that employs me
I agree that copies made under these circumstances will continue to carry the copyright notice that appears in the original published work. I agree to inform my co-authors, if any, of the above terms. I certify that I have obtained written permission for the use of text, tables, and/or illustrations from any copyrighted source(s), and I agree to supply such written permission(s) to JTEC upon request.