Motor Units Action Potentials
Mostrando 1-12 de 22 artigos, teses e dissertações.
-
1. A novel method for EMG decomposition based on matched filters
Introduction Decomposition of electromyography (EMG) signals into the constituent motor unit action potentials (MUAPs) can allow for deeper insights into the underlying processes associated with the neuromuscular system. The vast majority of the methods for EMG decomposition found in the literature depend on complex algorithms and specific instrumentation.
Res. Biomed. Eng.. Publicado em: 2015-03
-
2. Decomposição de sinais eletromiográficos de superfície utilizando Modelos ocultos de Markov
A captação de sinais fisiológicos provenientes do Sistema Motor, que pode ser realizada pela eletromiografia, tem sido cada vez mais utilizada na prática clínica para auxiliar o terapeuta no diagnóstico de distúrbios motores. Desta forma, o processo de decomposição de sinais eletromiográficos (EMG), que inclui a identificação e classificação do
Publicado em: 2010
-
3. Mathematical modeling and simulation of motor unit action potencials. / Modelagem matemática e simulação de potenciais de ação de unidades motoras.
This work presents the mathematical model and simulation of motor unit action potentials of vertebrate muscles aiming at after simulation of the electromyogram. To obtain this, initially, it was made a compilation of several data about the distribution of muscle fibers (FBs) in motor units (MUs) of many muscles, and the mathematical models of the action pote
Publicado em: 2006
-
4. Nerve potentials and afferent conduction velocities in the differential diagnosis of amyotrophy of the hand
Nerve action potentials recorded over the elbow after stimulation of the wrist were studied in patients with hand amyotrophy of different origin. In amyotrophic lateral sclerosis the amplitude of nerve action potentials does not change significantly even with extreme muscle wasting and loss of motor units.
-
5. Short-term stability of single motor unit recordings in motor neuron disease: a macro EMG study.
Thirty five individual macro EMG motor unit potentials in 13 patients with motor neuron disease were recorded every 15 minutes during a 2 hour period. No significant change in amplitude or area was seen in 15 control units in nine patients or in 20 units in 11 patients receiving RX77368 0.2-0.3 mg/kg. The findings provide no evidence for an action of this lo
-
6. Neuromuscular transmission in human single motor units.
A method, multiple point stimulation, has been reported to isolate 5-20 single hypothenar or thenar motor units for investigation. This method is attractive for testing neuromuscular transmission because the required stimulus intensities are much less than for supramaximal nerve stimulation, and movement artefact is less of a problem. In this investigation o
-
7. Characteristics of the F response: a single motor unit study.
Trains of 100 to 200 stimuli result in F discharges from less than one half of motor units of hand muscles. The maximum observed F discharge frequency was 10%. There was no relation between the surface voltage of motor unit potentials and the frequency of F discharge. The motor unit potentials of larger surface voltage were recruited at higher stimulus inten
-
8. The fatigue of voluntary contraction and the peripheral electrical propagation of single motor units in man
1. Single human motor units from the short extensors of the toes were classified by their voluntary threshold and axonal conduction velocity. The voluntary discharge intervals, and the shortest discharge intervals at which action potentials were conducted to the muscle fibres, were studied during maximal voluntary effort maintained for 1 min, and were compar
-
9. Variation of motor unit size in the human extensor digitorum brevis and thenar muscles1
One physiological method for estimating the motor unit number in a muscle depends on dividing into the maximum compound muscle action potential, the potential average of the first few motor unit potentials excited by a motor nerve stimulus above motor threshold. To be valid, such an average unit potential size must be representative of the whole motor unit p
-
10. Quantitative electrophysiological study of alcoholic neuropathy.
Thirty-one chronic alcoholic patients were investigated using quantitative electrophysiological techniques. Estimates of the numbers of functioning motor units in the extensor digitorum brevis muscles and measurements of the parameters of the potentials of these units are presented along with the values for motor nerve conduction velocities in the innervatin
-
11. Recruitment and rate coding organisation for soleus motor units across entire range of voluntary isometric plantar flexions
Unlike upper limb muscles, it remains undocumented as to how motor units in the soleus muscle are organised in terms of recruitment range and discharge rates with respect to their recruitment and de-recruitment thresholds. The possible influence of neuromodulation, such as persistent inward currents (PICs) on lower limb motor unit recruitment and discharge r
Blackwell Science Inc.
-
12. Synchronization of motor units in human masseter during a prolonged isometric contraction.
1. The action potentials of concurrently active motor units in human masseter were recorded on several fine-wire intramuscular electrodes and synchronization was assessed by cross-correlation of their firing times. 2. Long recording sessions and a test of significance for peaks in histograms were used to enhance detection of synchrony. 3. Synchrony in masset