5.15 Studies of Spectral Properties of Radiation Scattered by Blood …
477
The studies of spectral properties of radiation scattered by human skin during
artificially caused ischemia in the part of the limb under study showed that with an
increase of the degree of ischemia, that is with the decrease of the degree of blood
oxygenation, the value of two relatively local extremums decreases to zero and after
becomes negative. The curve of the dependence of the change of relative value of
second local extremum (λ 2 , λ 3 ) on the degree of compressing the limb was made.
During the removal of air-inflated collar, abrupt increase of relative quantity of
extremum happens. According to the conducted studies, the given spectral method
could be used for the estimation of the degree of ischemia and the level of oxygenation
of human skin.
5.16 Results and Conclusions
The studies dedicated to the development of speckle-optical methods for determination of parameters such as velocity of contraction and deformations of diffuse
objects, which are nerve stems, muscles, epithelial tissues, were conducted.
1. The technique of the study of the contraction process of muscle tissue, based on
speckle counting, was developed. The dependence of the velocity of contraction
of biceps muscle of thigh of a frog on time and mechanical load was experimentally studied. The conducted studies showed two phases of contraction: The
first, relatively short (10–80 ms), corresponds to the active process of muscles
contraction, and the second (150–200 ms)—to the passive process of relaxation.
Absolute values of the maximal velocity of contraction depend on the size of outer
stretching force and are different for various preparations (reach several dozens
of meters within a second). It was shown that the maximal velocity of muscle
contraction develops in 20 ms at duration of all phase of muscle contraction of 80
ms. During the relaxation, maximal velocity values are approximately two times
smaller. Derived information coincides with the results of direct myography traditionally applied for the studies of muscle contraction. At the same time, the used
method possesses a number of advantages: It is contactless, allows conducting
studies by placing the preparation arbitrary and not even extracting it, is zero
inertia and allows studying the movement of separate small areas of preparation.
2. The method of double-pulsed speckle-interferometry in real time for the determination of longitudinal shift of an object (muscle), which allows increasing the
limit of measurable shifts by two orders in regard to the shift range determined by
the known techniques, was suggested and experimentally realized. The principal
possibility of using speckle-interferometry for the study of surface deformations
of human tissues was shown. On the setup developed with the use of monopulse
ruby laser λ = 694 nm, with the help of double-pulsed speckle-photography
method with the accuracy of ~10 μm the field of deformation of surface tissues
at the process of muscle contraction from the surface (2 cm
2 ) at spatial resolution
of 2–4 mm
2 in 20 s after the beginning of contraction was studied. The vector
477
The studies of spectral properties of radiation scattered by human skin during
artificially caused ischemia in the part of the limb under study showed that with an
increase of the degree of ischemia, that is with the decrease of the degree of blood
oxygenation, the value of two relatively local extremums decreases to zero and after
becomes negative. The curve of the dependence of the change of relative value of
second local extremum (λ 2 , λ 3 ) on the degree of compressing the limb was made.
During the removal of air-inflated collar, abrupt increase of relative quantity of
extremum happens. According to the conducted studies, the given spectral method
could be used for the estimation of the degree of ischemia and the level of oxygenation
of human skin.
5.16 Results and Conclusions
The studies dedicated to the development of speckle-optical methods for determination of parameters such as velocity of contraction and deformations of diffuse
objects, which are nerve stems, muscles, epithelial tissues, were conducted.
1. The technique of the study of the contraction process of muscle tissue, based on
speckle counting, was developed. The dependence of the velocity of contraction
of biceps muscle of thigh of a frog on time and mechanical load was experimentally studied. The conducted studies showed two phases of contraction: The
first, relatively short (10–80 ms), corresponds to the active process of muscles
contraction, and the second (150–200 ms)—to the passive process of relaxation.
Absolute values of the maximal velocity of contraction depend on the size of outer
stretching force and are different for various preparations (reach several dozens
of meters within a second). It was shown that the maximal velocity of muscle
contraction develops in 20 ms at duration of all phase of muscle contraction of 80
ms. During the relaxation, maximal velocity values are approximately two times
smaller. Derived information coincides with the results of direct myography traditionally applied for the studies of muscle contraction. At the same time, the used
method possesses a number of advantages: It is contactless, allows conducting
studies by placing the preparation arbitrary and not even extracting it, is zero
inertia and allows studying the movement of separate small areas of preparation.
2. The method of double-pulsed speckle-interferometry in real time for the determination of longitudinal shift of an object (muscle), which allows increasing the
limit of measurable shifts by two orders in regard to the shift range determined by
the known techniques, was suggested and experimentally realized. The principal
possibility of using speckle-interferometry for the study of surface deformations
of human tissues was shown. On the setup developed with the use of monopulse
ruby laser λ = 694 nm, with the help of double-pulsed speckle-photography
method with the accuracy of ~10 μm the field of deformation of surface tissues
at the process of muscle contraction from the surface (2 cm
2 ) at spatial resolution
of 2–4 mm
2 in 20 s after the beginning of contraction was studied. The vector