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Medical and Biological Engineering and Computing

, Volume 24, Issue 5, pp 506–512 | Cite as

Model for decomposition of the motor unit action potential 1 The algorithm

  • Y. Lööf
Article

Abstract

A model for decomposition of the motor unit action potential (MUAP) into its constituent single-fibre action potentials is presented. It finds an optimal fit of a set of simulated single-fibre action potentials (SSFAPs) to the MUAP. The SSFAPs are assumed to originate from muscle fibres at different distances from the electrode, having various delays in time. Two methods for decomposition of the MUAP are derived from this model: first, that the MUAP is decomposed into a fixed set of SSFAPs; and secondly that the MUAP is decomposed into an adaptive, expanding set of SSFAPs. In the second method three steps are used repeatedly. First, the MUAP is cross-correlated with a collection of four SSFAPs. Then the most similar SSFAPs are used to reconstruct the original MUAP. The reconstruction thus obtained is subtracted from the original MUAP to detect activity not yet imitated. This difference (‘residual’) is again used for cross-correlation, restarting in step 1. After a suitable number of iterations, the MUAP is optimally imitated by a set of SSFAPs. The set of SSFAPs, obtained as described, is assumed to give information about underlying anatomical and physiological data (such as fibre number, fibre density, impulse dispersion) of the motor unit under study.

Keywords

Action potential Computer simulations Cross-correlation Decomposition Electromyography Factor analysis Mathematical model Method Motor unit 

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Copyright information

© IFMBE 1986

Authors and Affiliations

  • Y. Lööf
    • 1
  1. 1.Department of Clinical NeurophysiologyUniversity HospitalUppsalaSweden

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