**7. References**


Ikuta, K.; Hasegawa, M. & Goto, H. (2007). Total System of Hyper Finger for Remote Minimally Invasive Surgery (The 9th Report) Proposal and Experimental Verification of Safety Operation Strategies, *Proceedings of the 16th Annual Meeting of The Japan Society of Computer Aided Surgery*, pp. 43-44

**Chapter 1**

**Chapter 11**

**EMG Decomposition and Artefact Removal**

Traditionally, in clinical electromyography (EMG), neurophysiologists assess the state of the muscle by studying basic units of an EMG signal, which are referred to as motor unit action potentials (MUAPs). Information regarding the morphology and rate of occurrence of MUAPs is often used for diagnosis of neuromuscular disorders. In addition, recent studies have shown that the analysis of the energy content of MUAPs is a possible way for discriminating among normal, neurogenic, and myopathic MUAPs [38], illustrating, thus, the clinical value of the

A common way of obtaining such information is by observing MUAP activities on an oscilloscope and listening to their audio characteristics over the speakers. When doing this, the researcher is implicitly performing a time and frequency analysis of MUAPs. However, the results of this analysis are dependent on the experience of the investigator and on his ability to extract relevant information from the visual and auditory analysis. Furthermore,

The drawbacks related to the procedure described above have motivated the use of computer-based techniques for extraction of MUAPs from EMG signals [3, 19, 22, 27, 29, 32, 40]. Such methods, also known as EMG decomposition techniques, aim at classifying MUAPs generated by a common source into the same group. The results of this classification may provide information regarding the orchestration of the neuromuscular system, and therefore of the state of the muscle. A similar problem, often referred to as spike sorting, is found in the study of neuronal activities [25]. In this case, neuronal action potentials from the same source

Originally, the investigation of MUAP activities belonged to needle electromyographic (NEMG) studies, mainly because surface electrodes may easily produce an integration of many potentials, which precludes accurate study of their individual form. However, some recent studies have shown that the use of surface electrodes may be successfully applied for

> ©2012 Andrade et al., licensee InTech. This is an open access chapter distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly

©2012 Andrade et al., licensee InTech. This is a paper distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Adriano O. Andrade, Alcimar B. Soares, Slawomir J. Nasuto and Peter J. Kyberd

http://dx.doi.org/10.5772/50819

interpretation of MUAP information.

are classified into a common group.

this procedure is time-consuming and prone to error.

cited.

**1. Introduction**

Additional information is available at the end of the chapter

