| Summary: | 碩士 === 國立成功大學 === 醫學工程研究所 === 86 === AbstractAnalysis of single motor unit (MU) discharge patterns
provides an understanding of the neurophysiologic basis for
quantifying the motor control ability. The aim of this research
is to apply the surface motor unit action potentials (MUAPs)
measured with noninvasive multielectrode for studying the firing
characteristics of stroke, neuropathy, myopathy, and healthy
volunteers.To investigate the firing rate variation, the
measures of singular value decomposition (SVD), joint interval
histogram (JIH), and autoregessive model (AR), derived from
interpulse interval (IPI) train, were adopted in this research.
This study first verifies the JIH parameters, including slope
and area obtained from the AR model of simulated IPI sequences.
Our simulation results indicate that the JIH slope reflects the
stability of firing sequence and the JIH area indicates the
whole firing variation. However, the measurement of SVD slope is
too sensitive to the data distribution which is discarded in
later clinical studies. Furthermore, this study extends the JIH
representation to the second-order AR model. For second-order AR
model, the firing characteristics can be observed from the
location of poles, in terms of radius and phasic angle in z-
plane. The phasic angle of the dominated pole, i.e. with larger
radius, can be used to quantify the firing stability. An IPI
sequence with larger radian of phasic angle indicates better
controllability and vice versus.For each of the recruited
subjects, sessions of the electromyographic (EMG) signal from
the first dorsal interosseus (1st DI) during voluntary and
isometric contraction were recorded. A multistage approach,
including spatial filtering for peak localization and spatial
decomposition for overlapping MUAPs, was utilized for the MU
activity analysis of stroke patients. From limited numbers of
clinical cases, the changes of firing characteristics of stroke
patient, a upper motor neuron disease, significantly differ from
the normal mainly in JIH slope indicating lower firing
stability. However, the subjects with neuropathy and myopathy
have higher firing variation in comparison with that of normal
subjects. Our results indicate that the extracted parameters of
the JIH ellipse as well as AR model can provide quantitative
assessment for motor control ability in stroke patients.
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