412
5 Laser Specklometer, Speckle-Optical Diagnostics and Laser …
possibility to judge about the good coincidence of the results. Besides unlike the
laser vibrometer, the laser specklometer gave the possibility to register the vibration
frequency of the working facet of the microinstrument along with the amplitude.
5.6 Technique for Obtaining Primary Information Using
Laser Specklometer
Intensity fluctuation spectra of the scattered laser radiation from the human body
surface are registered using the scheme (see Fig. 5.27b) for study of functional state
of muscles using the laser specklometer (see Fig. 5.27a). The illuminating–receiving
head (IRH) is laid on the studied body surface with a soft strap. Meanwhile, minimal
pressure on the muscle is reached so that a normal physiological behavior is not
broken in it.
The illuminated area was covered with the elastic white diffuser to achieve homogeneous conditions of diffusion in different experiments without the influence of
blood flow surface while studying muscles.
The scattered radiation, which forms a speckle-field, is received by the receiving
light guide, the aperture of which matches the speckle size and is transmitted into the
photodetector. The amplifying signal is proportional to the random time measurement of intensity and corresponds to the functional state of the muscle under study
(surface blood flow). The signal is analyzed with low-frequency spectrum analyzer
(Fig. 5.28a) having the range between 0.02 and 2000 Hz (with further registration
on a recorder) or with an electronic processing unit, or, finally, with a PC with an
interface block (Fig. 5.28b). The spectrum analyzer SK4-72 gives the possibility
to determine the full spectrum of intensity fluctuations of a dynamic speckle-field
formed by the scattered radiation from the reflective covering on the skin above the
muscle (Fig. 5.28c).
The analysis of the full spectrum gives the opportunity to calculate, for example,
parameters such as deviation of spectral amplitudes at different frequencies and area
under the spectral curve. The electronic processing unit and the PC with the interface
block allow obtaining the same parameters, but in the automatic mode.
The muscle tone research program includes registration of intensity fluctuation
spectra of the scattered laser radiation from the surface above the paravertebral
muscles of coupling and thorax from both sides while sitting at rest and during
tonic reactions: inspiration, head rotation to the right, to the left, down, bend over of
the body back and forth for 30° and to the maximal degree, of gastrocnemius muscles
of both legs by turn.
As an example in the standing position, there were registered intensity fluctuation
spectra of the speckle-field from paravertebral muscles, muscles of the front surface
of the lower one-third of a thigh (Fig. 5.29a), back surface of lower one-third of a shin
(Fig. 5.29b), area of a hallux at rest and during isometric contraction of extremity
muscles (Fig. 5.29c).
5 Laser Specklometer, Speckle-Optical Diagnostics and Laser …
possibility to judge about the good coincidence of the results. Besides unlike the
laser vibrometer, the laser specklometer gave the possibility to register the vibration
frequency of the working facet of the microinstrument along with the amplitude.
5.6 Technique for Obtaining Primary Information Using
Laser Specklometer
Intensity fluctuation spectra of the scattered laser radiation from the human body
surface are registered using the scheme (see Fig. 5.27b) for study of functional state
of muscles using the laser specklometer (see Fig. 5.27a). The illuminating–receiving
head (IRH) is laid on the studied body surface with a soft strap. Meanwhile, minimal
pressure on the muscle is reached so that a normal physiological behavior is not
broken in it.
The illuminated area was covered with the elastic white diffuser to achieve homogeneous conditions of diffusion in different experiments without the influence of
blood flow surface while studying muscles.
The scattered radiation, which forms a speckle-field, is received by the receiving
light guide, the aperture of which matches the speckle size and is transmitted into the
photodetector. The amplifying signal is proportional to the random time measurement of intensity and corresponds to the functional state of the muscle under study
(surface blood flow). The signal is analyzed with low-frequency spectrum analyzer
(Fig. 5.28a) having the range between 0.02 and 2000 Hz (with further registration
on a recorder) or with an electronic processing unit, or, finally, with a PC with an
interface block (Fig. 5.28b). The spectrum analyzer SK4-72 gives the possibility
to determine the full spectrum of intensity fluctuations of a dynamic speckle-field
formed by the scattered radiation from the reflective covering on the skin above the
muscle (Fig. 5.28c).
The analysis of the full spectrum gives the opportunity to calculate, for example,
parameters such as deviation of spectral amplitudes at different frequencies and area
under the spectral curve. The electronic processing unit and the PC with the interface
block allow obtaining the same parameters, but in the automatic mode.
The muscle tone research program includes registration of intensity fluctuation
spectra of the scattered laser radiation from the surface above the paravertebral
muscles of coupling and thorax from both sides while sitting at rest and during
tonic reactions: inspiration, head rotation to the right, to the left, down, bend over of
the body back and forth for 30° and to the maximal degree, of gastrocnemius muscles
of both legs by turn.
As an example in the standing position, there were registered intensity fluctuation
spectra of the speckle-field from paravertebral muscles, muscles of the front surface
of the lower one-third of a thigh (Fig. 5.29a), back surface of lower one-third of a shin
(Fig. 5.29b), area of a hallux at rest and during isometric contraction of extremity
muscles (Fig. 5.29c).