Alexey V. Sedykh

Comparison of lymph and blood flow in microvessels: coherent optical measurements

In the present study the characteristics of blood and lymph microcirculation are investigated. The microcirculation was studied on small intestine mesentery in norm and during NG-nitro-L-arginine (L- NNA) application. The direct measurement of lymph flow velocity (parameter V) in individual microvessels was based on the technique of light intravital videomicroscopy. The first spectral moments of Doppler signal characterizing the mean velocities of lymph and blood flow in microvessels (parameters M1L and M1B) were measured by speckle- interferometrical method. Simultaneously, diameters of blood and lymph microvessels as well as parameters of phasic contractions and valve function of lymphatics were registered. The mean diamters of investigated lymphatics and venules were 170±20 μm and 8±0.5 μm, correspondingly. In 24% of lymph microvessels phasic contractions were observed. The mean flow velocity in blood microvessels was 10 times more than the one in lymphatics. L-NNA application led to variable effects on diameter of lymphatics, increased the number of microvessels with phasic contractions and modified parameters of these contractions. The mean velocity of lymph flow (V) was increased. The mean value of M1L was not changed; the M1L maximum in 75% of the lymphatics was increased. In 88% of venules M1B was decreased on 25±7%.

Analysis of lymph flow in microvessels by biomicroscopic and coherent optical methods

The lymph flow velocity in microvessels of rat mesentery was investigated by using biomicroscopic manual frame-by-frame technique with image processing system and speckle- interferometrical method. Lymph flow was observed in the majority of lymphatics. Lymph flow was registered in microvessels with phasic contractions and functioning valves. The lymphocytes motion in flow was measured. It was established that mean lymph flow velocity increased in vessels with phasic contractions and moderate concentration of lymphocytes in flow. The application of speckle- interferometry allowed us to estimate lymph flow on the whole with all stops, the increases and decreases of flow velocity. The parameters both of changes of a mean velocity and of spatial-temporal velocity distribution in lymph flow were calculated. Temporal changes of the parameter V showed a shuttle-type character of lymph flow velocity.

Peculiarities of lymph flow in microvessels

In the present study the characteristics of lymph flow in microvessels are investigated in vivo by the speckle- interferometrical and biomicroscopic methods. Two parameters of the lymph flow velocity are determined. The first frequency-weighted spectral moment of Doppler signal (M1) was calculated. This parameter is proportional to lymph flow velocity. In the same regions of lymphatics the velocity of translational motion of the signal lymphocytes in the flow is assessed. The value of velocity and the parameter M1 essentially varied. The temporary dynamics of M1 indicated that the lymph flow had the alternating- translational character. Simultaneously the diameter of lymph microvessel, the amplitude and the rate of phasic contraction and the rate of valve functioning are registered. NG-nitro-L-arginine (L-NNA, 10-4 M), an inhibitor of nitric oxide synthase, is topically applied during 15 min. The application of L-NNA provoked the modulation of alternating-translational motion of lymph flow, the changes of diameters and rate of valve function and the stimulating of phasic contractions and the correlation between parameters of lymph microcirculation.

Temporal dynamics of blood microcirculation in oral cavity mucous membrane caused by low-intensity laser irradiation

Effects of laser at the wavelength of 650 nm on the isolated vessels of white rat mesentery have been analyzed. Influence of laser irradiation on the statement of blood microcirculation in mucous membrane of human oral cavity has been investigated. Temporal changes of hemodynamics have been studied by methods of laser photoplethysmography, Doppler diagnostics and laser speckle imaging technique. Influence of coherent light (at the wavelength 630 nm) on the intensity of microcirculation in the capillary net of mucous membrane has been demonstrated directly during the short-time session of laser therapy.

Laser Doppler diagnostics for orthodontia

The results of statistical analysis of Doppler spectra of intensity fluctuations of light, scattered from mucous membrane of oral cavity of healthy volunteers and patients, abused by the orthodontic diseases, are presented. Analysis of Doppler spectra, obtained from tooth pulp of patients, is carried out. New approach to monitoring of blood microcirculation in orthodontics is suggested. Influence of own noise of Doppler measuring system on formation of the output signal is studied.

Influence of coherent light on blood microcirculation in human oral cavity mucous membrane: an objective monitoring by laser photoplethysmography and Doppler flowmetry

Integrated device for laser therapy and monitoring of blood microcirculation has been developed. Influence of laser irradiation on the statement of blood microcirculation in mucous membrane of human oral cavity has been investigated. Changes of blood saturation and velocity of blood microcirculation have been studied by methods of laser photoplethysmography and Doppler diagnostics. Influence of coherent light on the intensity of microcirculation in the capillary net of mucous membrane has been demonstrated directly during the short-time session of laser therapy.

Speckle methods for investigation of temporal dynamics of blood microcirculation in oral cavity mucous membrane

Influence of laser irradiation on the statement of blood microcirculation in mucous membrane of human oral cavity has been investigated. Temporal changes of hemodynamics have been studied by methods of laser photoplethysmography, Doppler diagnostics and laser confocal microscopy. Influence of coherent light (at two wavelength 850 nm and 630 nm) on the intensity of microcirculation in the capillary net of mucous membrane has been demonstrated directly during the short-time session of laser therapy.

Speckle interferometry for analysis of blood microcirculation in dentistry

The results of statistical analysis of spectra of intensity fluctuation of light, scattered from oral cavity membrane and teeth pulp, are presented. The dependence of the spectral moments of speckle-interferometric signal on the cutoff frequency is investigated. Influence of own noise of measuring system on formation of speckle-interferometric signal is studied. Dependencies of scattering properties of biotissues on characteristics of speckle interferometric and Doppler signals are analyzed. New algorithms to statistical processing of measuring are suggested.

Laser diagnostics in orthodontics

The results of statistical analysis of Doppler spectra of intensity fluctuations of light, scattered from mucose membrane of oral cavity of healthy volunteers and patients, abused by the orthodontic diseases, are presented. Analysis of Doppler spectra, obtained from tooth pulp of patients, is carried out. New approach to monitoring of blood microcirculation in orthodontics is suggested. Influence of own noise of measuring system on formation of the speckle-interferometric signal is studied.

Doppler and speckle methods for diagnostics in dentistry

The results of statistical analysis of Doppler spectra of scattered intensity, obtained from tissues of oral cavity membrane of healthy volunteers, are presented. The dependence of the spectral moments of Doppler signal on cutoff frequency is investigated. Some results of statistical analysis of Doppler spectra, obtained from tooth pulp of patients, are presented. New approach for monitoring of blood microcirculation in orthodontics is suggested. Influence of own noise of measuring system on formation of speckle-interferometric signal is studied.