Decomposition of electromyogram (EMG) provides a valuable means of obtaining motor unit recruitment and firing rate information. The feasibility of decomposing surface EMG signals into their constituent motor unit action potential (MUAP) trains using independent component analysis (ICA) was examined using simulated EMG data. Surface EMG signals detected with an array of nine electrodes were sim...

In the present study, the adapted multiple point stimulation (AMPS) method was first applied to median innervated thenar muscles in 22 amyotrophic lateral sclerosis (ALS) patients who did not received any treatment. In all patients, a motor unit number estimate (MUNE) and an average surface-recorded motor unit action potential (S-MUAP) size have been derived even if the denervation was severe; ...

A novel electromyography (EMG) signal decomposition framework is presented for the thorough and precise analysis of intramuscular EMG signals. This framework first detects all of the active motor unit action potentials (MUAPs) and assigns single MUAP segments to their corresponding motor units. MUAP waveforms that are found to be superimposed are then resolved into their constituent single MUAP...

New surface electromyogram (SEMG) techniques offer the potential to advance knowledge of healthy and diseased motor units. Conduction velocity (CV) estimates, obtained from indwelling electrodes, may provide diagnostic information, but the standard method of CV estimation from SEMG may be of only limited value. We developed a motor unit (MU) tracking algorithm to extract motor unit conduction v...

Surface electromyogram (EMG) finds many applications in the non-invasive characterization of muscles. Extracting information on control motor units (MU) is difficult when using single channels, e.g., due to low selectivity and large phase cancellations MU action potentials (MUAPs). In this paper, we propose a new method face problem case differential channel. The signal approximated as sum conv...

We studied the innervation and organization of motor units in the brachioradialis muscle of 25 normal human subjects. We recorded intramuscular EMG signals at points separated by 15 mm along the proximodistal muscle axis during moderate isometric contractions, identified from 27 to 61 (mean 39) individual motor units per subject using EMG decomposition, and estimated the locations of the endpla...

Pathologic progression in amyotrophic lateral sclerosis (ALS) results from motor neuron death, while the clinical expression also reflects the compensatory effects of collateral reinnervation consequent to lower motor neuron loss. In a cross-sectional study of ALS subjects, we made comparisons between motor unit number estimation (MUNE) values and several measures reflecting collateral reinnerv...

Over the past 3 decades, various algorithms used to decompose the electromyographic (EMG) signal into its constituent motor unit action potentials (MUAPs) have been reported. All are limited to decomposing EMG signals from isometric contraction. In this report, we describe a successful approach to decomposing the surface EMG (sEMG) signal collected from cyclic (repeated concentric and eccentric...