5 Laser Specklometer, Speckle-Optical Diagnostics and Laser …
373
of transversal resonance oscillations of the muscle during its contraction [111].
Myoacoustic signals were used for analysis of muscular activity, in particular, for
measurement of muscular fatigue [112, 113].
The study of muscular sounds of healthy people and patients who suffer from
neuromuscular pathologies (myasthenia, polymyotoxia, polymyelitis, special muscle
atrophies, Friedreich’s ataxia, etc.) has shown reliable differences in average peak
frequencies of sound oscillations in normal state and in pathology. The test people
with neuromuscular pathologies generated signals, the amplitude of which was from
1/5 to ½ of the amplitude of signals detected in the group of healthy people [114].
Despite a number of interesting results obtained with the acoustic myography
method, it is already clear that the study of muscle oscillations can be supplemented
successfully with a rather simple method of speckle-optical myography due to a
certain degree of noises in the low-frequency area (traffic noises, steps, etc.), filtration of which is a more complicated task, than filtration of high-frequency sounds
(speech, etc.), and, correspondingly, a low special resolution. This method has a
higher spatial resolution and protection in comparison with the method of acoustic
myography. And advantages of optical methods such as contactlessness, remoteness and non-invasiveness give the possibility to overcome disadvantages of acoustic
methods connected with the application of contact microphones, which reduce penetration of low-frequency background noises into the measurement section through the
air [110].
One of the perspective directions is the development and implementation of
coherent-optical research methods based on achievements of modern laser equipment. These research methods give the possibility to study processes of appearance
and development of such a kind of diseases with high sensitivity and accuracy and
high spatial resolution. The methods are based on the analysis of time–spatial correlation characteristics of laser radiation scattered by the living tissue and on determination of velocities, shifts, deformations, roughness and other characteristics of the
objects under study with their help.
After the studies conducted by the author and his group, it was first found that
changing of muscle tone, which is accompanied by changes of oscillations of muscle
fibers and the surrounding tissues, deforms the spectrum of the speckle-field [80–82,
115–134]. These works were conducted in the Institute of Neurology, Neurosurgery
and Physiotherapy of the Ministry of Health of the Republic of Belarus for 20 years
on the initiative of L. V. Tanin, a Leading Scientific Researcher of the Institute of
Physics of the NAS of Belarus, with the assistance and understanding the perspectives
of this school by Professor I. P. Antonov, Academician, the Head of the Institute
of Neurology, Neurosurgery and Physiotherapy of the Ministry of Health of the
Republic of Belarus.
It was shown that measurements of spectral characteristics of dynamic laser
speckle-field formed during reflection of the light from the tissue over the contracting
muscle can serve as a serious alternative to sound myography considering high
protection and significantly supplement the study of contractile function.
That is why the aim of the study was development of brand-new method of laser
medicine in investigation of biomechanical characteristics of skeletal muscles, which
373
of transversal resonance oscillations of the muscle during its contraction [111].
Myoacoustic signals were used for analysis of muscular activity, in particular, for
measurement of muscular fatigue [112, 113].
The study of muscular sounds of healthy people and patients who suffer from
neuromuscular pathologies (myasthenia, polymyotoxia, polymyelitis, special muscle
atrophies, Friedreich’s ataxia, etc.) has shown reliable differences in average peak
frequencies of sound oscillations in normal state and in pathology. The test people
with neuromuscular pathologies generated signals, the amplitude of which was from
1/5 to ½ of the amplitude of signals detected in the group of healthy people [114].
Despite a number of interesting results obtained with the acoustic myography
method, it is already clear that the study of muscle oscillations can be supplemented
successfully with a rather simple method of speckle-optical myography due to a
certain degree of noises in the low-frequency area (traffic noises, steps, etc.), filtration of which is a more complicated task, than filtration of high-frequency sounds
(speech, etc.), and, correspondingly, a low special resolution. This method has a
higher spatial resolution and protection in comparison with the method of acoustic
myography. And advantages of optical methods such as contactlessness, remoteness and non-invasiveness give the possibility to overcome disadvantages of acoustic
methods connected with the application of contact microphones, which reduce penetration of low-frequency background noises into the measurement section through the
air [110].
One of the perspective directions is the development and implementation of
coherent-optical research methods based on achievements of modern laser equipment. These research methods give the possibility to study processes of appearance
and development of such a kind of diseases with high sensitivity and accuracy and
high spatial resolution. The methods are based on the analysis of time–spatial correlation characteristics of laser radiation scattered by the living tissue and on determination of velocities, shifts, deformations, roughness and other characteristics of the
objects under study with their help.
After the studies conducted by the author and his group, it was first found that
changing of muscle tone, which is accompanied by changes of oscillations of muscle
fibers and the surrounding tissues, deforms the spectrum of the speckle-field [80–82,
115–134]. These works were conducted in the Institute of Neurology, Neurosurgery
and Physiotherapy of the Ministry of Health of the Republic of Belarus for 20 years
on the initiative of L. V. Tanin, a Leading Scientific Researcher of the Institute of
Physics of the NAS of Belarus, with the assistance and understanding the perspectives
of this school by Professor I. P. Antonov, Academician, the Head of the Institute
of Neurology, Neurosurgery and Physiotherapy of the Ministry of Health of the
Republic of Belarus.
It was shown that measurements of spectral characteristics of dynamic laser
speckle-field formed during reflection of the light from the tissue over the contracting
muscle can serve as a serious alternative to sound myography considering high
protection and significantly supplement the study of contractile function.
That is why the aim of the study was development of brand-new method of laser
medicine in investigation of biomechanical characteristics of skeletal muscles, which