460
5 Laser Specklometer, Speckle-Optical Diagnostics and Laser …
the blood pressure saturation after this procedure. In the line 2 corresponding to the
given spectrum of absorption of blood preparation, the lowering of the amplitude
of characteristic peaks at wavelengths of 542, 560, 577 nm is observed. Na 2 SO 4
was added to the cuvette studied by the preparation, which made it possible to bring
the concentration of oxyhemoglobin practically to zero. The line 3 shows complete
disappearance of characteristic peaks for wavelengths of 542 and 577 nm, and also
the changes of the sign of curvature of spectral curve for a wavelength of 560 nm.
Then, the cuvette with blood preparation was depressurized and stayed under normal
air pressure during 15 min. At this time, oxygen absorption occurred to a certain level.
In the line 4 corresponding to the absorption spectrum of blood preparation and at
the given degree of oxygenation, the characteristic peaks for wavelengths of 542 and
577 nm appear, and the sign of curvature for the given spectral curve at a wavelength
of 560 nm changes.
The obtained results allow concluding that change of the amplitudes of characteristic peaks of spectral curve at wavelengths of 542, 560 and 577 nm was connected
with the degree of oxygenation of the blood preparation and gives the possibility
to produce contactless noninvasive method of determination of the concentration of
oxyhemoglobin in blood. The measurement of spectral reflection coefficients from
human skin in vivo for three waves of 542, 560, 577 nm constitutes the essence of
this method. Let us introduce two coefficients Q 1 and Q 2 , which correspond to the
differences between amplitudes of spectral curve at wavelengths of 542, 577 nm and
amplitude of spectral curve for a wavelength of 560 nm:
Q 1 = A 542 −A 560 , Q 2 = A 577 −A 560 .
The results of the calculations of the coefficients Q 1 and Q 2 in the relative units
taking into account the sign of curvature are the following: for the line 1—Q 1 =
0.07, Q 2 = 0.08, for the line 2—Q 1 = 0.02, Q 2 = 0.02, for the line 3—Q 1 = −0.02,
Q 2 = −0.03, for the line 4—Q 1 = 0.05, Q 2 = 0.05. The derived information allows
building a calibrating diagram of the dependence of Q 1 and Q 2 from the degree of
saturation of O 2 of blood preparation (Fig. 5.61). The diagram allows determining
the degree of saturation of blood preparation with the oxygen. For instance, for the
condition determined by the curve 4 of blood preparation saturation spectrum, the
degree of saturation of O 2 equals to 13% from normal air pressure.
5.13.3 Measurement of Spectral Reflection Coefficients
of Skin In Vivo at Different Functional States
On the results of the studies of the same group of respondents (see Fig. 5.59), coefficients Q 1 and Q 2 have been calculated, which characterize, as stated above, the degree
of oxygenation of skin blood flow. The results of the calculations are provided in
Table 5.3.
5 Laser Specklometer, Speckle-Optical Diagnostics and Laser …
the blood pressure saturation after this procedure. In the line 2 corresponding to the
given spectrum of absorption of blood preparation, the lowering of the amplitude
of characteristic peaks at wavelengths of 542, 560, 577 nm is observed. Na 2 SO 4
was added to the cuvette studied by the preparation, which made it possible to bring
the concentration of oxyhemoglobin practically to zero. The line 3 shows complete
disappearance of characteristic peaks for wavelengths of 542 and 577 nm, and also
the changes of the sign of curvature of spectral curve for a wavelength of 560 nm.
Then, the cuvette with blood preparation was depressurized and stayed under normal
air pressure during 15 min. At this time, oxygen absorption occurred to a certain level.
In the line 4 corresponding to the absorption spectrum of blood preparation and at
the given degree of oxygenation, the characteristic peaks for wavelengths of 542 and
577 nm appear, and the sign of curvature for the given spectral curve at a wavelength
of 560 nm changes.
The obtained results allow concluding that change of the amplitudes of characteristic peaks of spectral curve at wavelengths of 542, 560 and 577 nm was connected
with the degree of oxygenation of the blood preparation and gives the possibility
to produce contactless noninvasive method of determination of the concentration of
oxyhemoglobin in blood. The measurement of spectral reflection coefficients from
human skin in vivo for three waves of 542, 560, 577 nm constitutes the essence of
this method. Let us introduce two coefficients Q 1 and Q 2 , which correspond to the
differences between amplitudes of spectral curve at wavelengths of 542, 577 nm and
amplitude of spectral curve for a wavelength of 560 nm:
Q 1 = A 542 −A 560 , Q 2 = A 577 −A 560 .
The results of the calculations of the coefficients Q 1 and Q 2 in the relative units
taking into account the sign of curvature are the following: for the line 1—Q 1 =
0.07, Q 2 = 0.08, for the line 2—Q 1 = 0.02, Q 2 = 0.02, for the line 3—Q 1 = −0.02,
Q 2 = −0.03, for the line 4—Q 1 = 0.05, Q 2 = 0.05. The derived information allows
building a calibrating diagram of the dependence of Q 1 and Q 2 from the degree of
saturation of O 2 of blood preparation (Fig. 5.61). The diagram allows determining
the degree of saturation of blood preparation with the oxygen. For instance, for the
condition determined by the curve 4 of blood preparation saturation spectrum, the
degree of saturation of O 2 equals to 13% from normal air pressure.
5.13.3 Measurement of Spectral Reflection Coefficients
of Skin In Vivo at Different Functional States
On the results of the studies of the same group of respondents (see Fig. 5.59), coefficients Q 1 and Q 2 have been calculated, which characterize, as stated above, the degree
of oxygenation of skin blood flow. The results of the calculations are provided in
Table 5.3.