Phonomyogram from single motor units during voluntary isometric contraction

Petitjean, Michel; Maton, B.

doi:10.1007/bf00854981

Cited by 40 publications

(44 citation statements)

References 29 publications

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“…The size of the air chamber is considered to have an effect on the MMG recording. Previous investigations employed different cylinder sizes ranging in length from 1 to 15 mm, although the diameters were similar (BOLTON et al, 1989;GOLDENBERG et al, 1991;PETITJEAN and BELLEMARE, 1994;PETITJEAN and MATON, 1995;CHEN et al, 1997;CELICHOWSKI et al, 1998;COURTEVlLLE et al, 1998). However, the optimal air chamber for the MMG measurement is still undetermined.…”

Section: Introductionmentioning

confidence: 95%

Mechanical behaviour of condenser microphone in mechanomyography

Watakabe

Mita

Akataki

et al. 2001

Med. Biol. Eng. Comput.

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Condenser microphones (MIC) have been widely used in mechanomyography, together with accelerometers and piezoelectric contact sensors. The aim of the present investigation was to clarify the mechanical variable (acceleration, velocity or displacement) indicated by the signal from a MIC transducer using a mechanical sinusoidal vibration system. In addition, the mechanomyogram (MMG) was recorded simultaneously with a MIC transducer and accelerometer (ACC) during voluntary contractions to confirm the mechanical variable reflected by the actual MMG and to examine the influence of motion artifact on the MMG. To measure the displacement-frequency response, mechanical sinusoidal vibrations of 3 to 300 Hz were applied to the MIC transducer with different sizes of air chambers (5, 10, 15 and 20 mm in diameter and 15, 20 or 25 mm long). The MIC transducer showed a linear relationship between the output amplitude and the vibration displacement, however, its frequency response declined with decreasing diameter and decreasing length of the air chamber. In fact, the cut-off frequency (-3dB) of the MIC transducer with the 5-mm-diameter chamber was 10, 8 and 4 Hz for the length 15, 20 and 25 mm, respectively. The air chamber with at least a diameter of 10 mm and a length of 15 mm is recommended for the MIC transducer. The sensitivity of this MIC transducer arrangement was 92 mV microm(-1) when excited at 100 Hz. During voluntary contraction, the amplitude spectral density function of the MMG from the MIC transducer resembled that of the double integral of the ACC transducer signal. The angle of the MIC transducer was delayed by 180 degrees in relation to the ACC transducer signal. The sensitivity of the MIC transducer was reduced to one-third because of the peculiar volume change of air chamber when the MMG was detected on the surface of the skin. In addition, the MIC transducer was contaminated by a smaller motion artifact than that from the ACC transducer. The maximal peak amplitude of the MIC and ACC transducer signal with the motion artifact was 7.7 and 12.3 times as much as the RMS amplitude of each signal without the motion artifact, respectively. These findings suggest that the MIC transducer acts as a displacement meter in the MMG. The MIC transducer seems to be a possible candidate for recording the MMG during dynamic muscle contractions as well as during sustained contractions.

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Section: Introductionmentioning

confidence: 95%

Mechanical behaviour of condenser microphone in mechanomyography

Watakabe

Mita

Akataki

et al. 2001

Med. Biol. Eng. Comput.

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“…2 Most previous studies have examined MMG responses during isometric muscle actions. 27,29,35,45 A recent investigation by Dalton and Stokes,12 however, reported a positive, linear relationship between MMG amplitude and force during dynamic submaximal concentric (r 2 = 0.88) and eccentric (r 2 = 0.81) muscle actions of the biceps brachii. Petitjean et al 30 also reported a linear relationship for the MMG amplitude-force relationship (r 2 = 0.85) for the biceps brachii and greater MMG amplitude during fast than slow movements.…”

mentioning

confidence: 94%

Mechanomyographic and electromyographic responses to eccentric and concentric isokinetic muscle actions of the biceps brachii

et al. 1998

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“…In the case of the MMG from a single motor unit, transducers attached to the skin have been used. As contact type transducers, microphones [13], piezoelectric sensors [14], and acceleration sensors [15] have all been previously used. An acceleration sensor is the smallest and lightest sensor among them.…”

Section: Discussionmentioning

confidence: 99%

System Identification of Mechanomyogram at Various Levels of Motor Unit Recruitment

Uchiyama

Tamura

2014

SICE Journal of Control, Measurement, and System Integration

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: The mechanomyogram from a single motor unit and the induced mechanomyogram at various levels of recruitment were measured with an acceleration sensor. The transfer functions between motor unit action potential (or electrical stimulation) and the mechanomyogram were identified using the singular value decomposition method. The purpose of this study is to clarify how the model order of the transfer function depends on the recruitment level. The second-to tenth-order transfer functions were calculated, and the difference between the observed and the estimated mechanomyograms using the transfer function, the fitness, was calculated. The relationship between the model order and the fitness was tested using the Holm-Bonferroni multiple comparison. At low levels (single motor unit, 20, and 40%) of recruitment, there were significant differences between the fourth-and higher-order models, but there were no significant differences between the fifth-and higher-order models. In contrast, at high levels (60, 80, and 100%) of recruitment, the fourth-order model did not show significant differences between the fifth-or higher-order models. As a result, the fifthand fourth-order models were appropriate at low and high recruitment levels, respectively. The differences in the order might be caused by interactions between active and resting motor units.

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Phonomyogram from single motor units during voluntary isometric contraction

Cited by 40 publications

References 29 publications

Mechanical behaviour of condenser microphone in mechanomyography

Mechanical behaviour of condenser microphone in mechanomyography

Mechanomyographic and electromyographic responses to eccentric and concentric isokinetic muscle actions of the biceps brachii

System Identification of Mechanomyogram at Various Levels of Motor Unit Recruitment

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