5.11 Experimental and Clinical Studies of Skin Microhemodynamics by …
443
The conducted studies deepen the impact of low-intensity laser irradiation on some
indicators of immune status, the processes of microcirculation, oxygen transfer–
blood function that improves the functional activity of the muscles and demonstrates
the feasibility of intravenous laser blood irradiation in complex treatment of patients
with traumatic and ischemic injury of peripheral nerves.
The dynamics of skin blood flow of the lower extremities in patients with neurologic manifestations of lumbar osteochondrosis in our experiments corresponded to
the changes in high-frequency spectra of intensity fluctuations of the speckle-field.
In this case the regional blood flow changes of lower limbs, which were detected
by the method of choralography and which reflect anti-spasmodic processes, were
accompanied by a drop of skin temperature and decrease in the frequency spectra of
fluctuations. On the contrary, at invariable regional blood flow (on the intact limb) and
at the absence of autonomic changes in the form of disturbances in thermoregulation
the frequency shift of the spectra of fluctuations in the higher frequency region was
observed. Consequently, the growth of the intensity of blood supply to the integumentary tissue and the increase of the blood flow in the microvasculature of the skin
are reflected in increasing contribution of high frequencies to the range of fluctuations of the speckle-field. This is also evidenced by the decline in the asymmetry of
the spectrum relative to the average frequency.
In the result of the studies, diagnostic speckle-optical criteria of violations of the
surface blood flow were developed, and microhemodynamic cards were experimentally obtained. It was established that for the assessment of dermal microhemodynamics the following parameters can be used: the average frequency of spectrum; the
area covered by the spectrum; the coefficient of asymmetry of the spectrum; the ratio
of the power spectral density levels at high and low frequencies; and the ratio of the
average frequency spectrum to the asymmetry. It is shown that different parameters
can characterize various links of the microcirculatory process. It is assumed that the
average frequency of the spectrum to a greater extent reflects the blood flow, and the
value of the area under the spectral curve reflects the capacity of the capillary bed,
the degree of capillaries opening.
Thus, the identified parameters of the spectra of fluctuations in the intensity
of dynamic speckle-field are characterized by both physiological and pathological
changes in the tissue and were used to assess the functional state of skin blood flow.
The studies of the microhemodynamics of human skin with artificially induced
ischemia and hypertension showed that as the diagnostic criteria, which characterize
the state of skin blood flow, the following indicators are the most informative: the
average frequency spectrum in the frequency range of 40–2000 Hz, the ratio of the
spectral density in the frequency range of 600–620 Hz to the spectral density in the
range of 40–60 Hz, the asymmetry of the spectrum relative to the average frequency,
the ratio of the average frequency spectrum to the coefficient of asymmetry, at that
the last parameter is the most sensitive indicator of microhemodynamics of the skin.
The values calculated by informative parameters corresponding to the point in
the area of the skin made it possible to construct microhemodynamic maps and
effectively evaluate the state of the surface of blood flow in normal and artificially
induced hyperemia in the skin area of 40 × 50 mm
2 .
443
The conducted studies deepen the impact of low-intensity laser irradiation on some
indicators of immune status, the processes of microcirculation, oxygen transfer–
blood function that improves the functional activity of the muscles and demonstrates
the feasibility of intravenous laser blood irradiation in complex treatment of patients
with traumatic and ischemic injury of peripheral nerves.
The dynamics of skin blood flow of the lower extremities in patients with neurologic manifestations of lumbar osteochondrosis in our experiments corresponded to
the changes in high-frequency spectra of intensity fluctuations of the speckle-field.
In this case the regional blood flow changes of lower limbs, which were detected
by the method of choralography and which reflect anti-spasmodic processes, were
accompanied by a drop of skin temperature and decrease in the frequency spectra of
fluctuations. On the contrary, at invariable regional blood flow (on the intact limb) and
at the absence of autonomic changes in the form of disturbances in thermoregulation
the frequency shift of the spectra of fluctuations in the higher frequency region was
observed. Consequently, the growth of the intensity of blood supply to the integumentary tissue and the increase of the blood flow in the microvasculature of the skin
are reflected in increasing contribution of high frequencies to the range of fluctuations of the speckle-field. This is also evidenced by the decline in the asymmetry of
the spectrum relative to the average frequency.
In the result of the studies, diagnostic speckle-optical criteria of violations of the
surface blood flow were developed, and microhemodynamic cards were experimentally obtained. It was established that for the assessment of dermal microhemodynamics the following parameters can be used: the average frequency of spectrum; the
area covered by the spectrum; the coefficient of asymmetry of the spectrum; the ratio
of the power spectral density levels at high and low frequencies; and the ratio of the
average frequency spectrum to the asymmetry. It is shown that different parameters
can characterize various links of the microcirculatory process. It is assumed that the
average frequency of the spectrum to a greater extent reflects the blood flow, and the
value of the area under the spectral curve reflects the capacity of the capillary bed,
the degree of capillaries opening.
Thus, the identified parameters of the spectra of fluctuations in the intensity
of dynamic speckle-field are characterized by both physiological and pathological
changes in the tissue and were used to assess the functional state of skin blood flow.
The studies of the microhemodynamics of human skin with artificially induced
ischemia and hypertension showed that as the diagnostic criteria, which characterize
the state of skin blood flow, the following indicators are the most informative: the
average frequency spectrum in the frequency range of 40–2000 Hz, the ratio of the
spectral density in the frequency range of 600–620 Hz to the spectral density in the
range of 40–60 Hz, the asymmetry of the spectrum relative to the average frequency,
the ratio of the average frequency spectrum to the coefficient of asymmetry, at that
the last parameter is the most sensitive indicator of microhemodynamics of the skin.
The values calculated by informative parameters corresponding to the point in
the area of the skin made it possible to construct microhemodynamic maps and
effectively evaluate the state of the surface of blood flow in normal and artificially
induced hyperemia in the skin area of 40 × 50 mm
2 .