Here, the wavelet analysis has been investigated to improve the quality of myoelectric signal before use in prosthetic design. Effective Surface Electromyogram (SEMG) signals were estimated by first decomposing the obtained signal using wavelet transform and then analysing the decomposed coefficients by threshold methods. With the appropriate choice of wavelet, it is possible to reduce interference noise effectively in the SEMG signal. However, the most effective wavelet for SEMG denoising is chosen by calculating the root mean square value and signal power values. The combined results of root mean square value and signal power shows that wavelet db4 performs the best denoising among the wavelets. Furthermore, time domain and frequency domain methods were applied for SEMG signal analysis to investigate the effect of muscle-force contraction on the signal. It was found that, during sustained contractions, the mean frequency (MNF) and median frequency (MDF) increase as muscle force levels increase.
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http://dx.doi.org/10.3109/03091902.2016.1139200 | DOI Listing |
J Clin Med
December 2024
Department of Neurology, National Institute of Medicine of the Ministry of Interior and Administration, 02-507 Warsaw, Poland.
Age-related changes to the orbicularis oculi muscle include impaired eyelid function, such as lagophthalmos, alterations in tear film dynamics, and aesthetic changes like wrinkles, festoons, and the descent of soft tissue. To date, the structural and functional changes that would comprehensively increase our understanding of orbicularis aging have not been analyzed. This study aims to investigate functional outcomes using surface electromyography and correlate them with ultrastructural changes in orbicularis during aging.
View Article and Find Full Text PDFSensors (Basel)
December 2024
School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
This study aimed to predict and fit the nonlinear dynamic grip force of the human upper limb using surface electromyographic (sEMG) signals. The research employed a time-series-based neural network, NARX, to establish a mapping relationship between the electromyographic signals of the forearm muscle groups and dynamic grip force. Three-channel electromyographic signal acquisition equipment and a grip force sensor were used to record muscle signals and grip force data of the subjects under specific dynamic force conditions.
View Article and Find Full Text PDFComput Biol Med
January 2025
Laboratory of Metrology and Information Processing, Physics Department, Faculty of Sciences, Ibn Zohr University, Agadir, Morocco.
Surface electromyography (sEMG), a non-invasive technique, offers the ability to identify insights into the activities of muscles in the form of electrical pulses. During the process of recording, the sEMG signals frequently become contaminated by a multitude of different artifacts, the origin of which may be attributed to numerous sources. These artifacts affect the reliability and accuracy of the pure sEMG activity, and subsequently reduce the quality of analysis and interpretation.
View Article and Find Full Text PDFJMIR Hum Factors
January 2025
Department of Biomedical Engineering, Chung Yuan Christian University, No. 200, Zhongbei Road, Zhongli District, Toayuan City, 32023, Taiwan, 886 32564507.
Background: Muscle fatigue, characterized by reduced force generation during repetitive contractions, impacts older adults doing daily activities and athletes during sports activities. While various sensors detect muscle fatigue via muscle activity, biochemical markers, and kinematic parameters, a real-time wearable solution with high usability remains limited. Plantar pressure monitoring detects muscle fatigue through foot loading changes, seamlessly integrating into footwear to improve the usability and compliance for home-based monitoring.
View Article and Find Full Text PDFAppl Physiol Nutr Metab
January 2025
Queensland University of Technology, School of Exercise and Nutrition Sciences, Kelvin Grove, Queensland, Australia;
This study examined the effects of core and muscle temperature on force steadiness and motor unit discharge rate (MUDR) variability after a hot-water immersion session. Fifteen participants (6 women; 25±6 years) completed neuromuscular assessments before and after either 42ºC (hot) or 36ºC (control) water immersion. Force steadiness was measured during knee extension, while HD-sEMG signals were recorded from vastus lateralis and medialis for MUDR variability analysis.
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