The sedimentation properties of blood of 13 ischemic heart disease patients and 2 healthy volunteers have been analyzed using a special computerized optical device for high temporal resolution tracing of red blood/plasma boundary movement rate (ESR-graphy). The kinetic curves of red blood sedimentation are substantially nonmonotonic and exhibit multiple accelerations, decelerations and even backwards movement of the red blood/plasma boundary. The intensity of blood sedimentation rate oscillations is significantly higher in the blood of patients and voluteers on days of enhanced geomagnetic activity than on quiet days. In healthy donors, blood oscillations were also observed on active geomagnetic days, however, their intensity was lower, the sedimentation rate started to oscillate after a longer time upon pipette installation, and the oscillation frequency was lower than in the patients' blood. Thus, blood is highly responsive to changes in geomagnetic field activity. Possibly oscillatory behavior mechanism of blood sedimentation rate and the diagnostic and prognostic merits of the ESR graphs are discussed.
The goal of the present work is to analyse multiple scattering in laser Doppler blood flowmetry reactive hyperaemia experiments. For this purpose, three different kinds of outputs from a laser Doppler flowmeter are studied: the concentration of moving blood cells (CMBC), the linearised unfiltered flux and the unlinerised unfiltered flux. Three vascular occlusion lengths of time are observed on eight healthy volunteers. For each reactive hyperaemia experiment, the difference between the linearised unfiltered flux and the unlinearised unfiltered flux is calculated to examine the multiple scattering. The latter is considered as a function of time and compared to blood flux and concentration of erthrocyte variations. This work shows that, during reactive hyperaemia, the multiple scattering is predominant when the CMBC signal reaches its peak, the latter occurring at the peak of perfusion. However, very rapidly the multiple scattering becomes negligible whereas the CMBC and the linearised flux still take high values. Moreover, the longer the occlusion length of time, the longer the presence of the multiple scattering.
Dynamic blood analysis requires real-time measurements. We introduce a novel optical scanning fiber-optic probe that can be used for rapidly acquiring sample data such as flow rates via doppler and dye luminescent decay kinetics over a spatial domain of interest. Experiments described demonstrate our high-speed wavelength tuned optical scanning probe concept. The scanning probe is based on wavelength multiplexing technique that offers simple control (via wavelength tuning). System issues such as probe beam scan distance, scan angle, beam spot size and optical efficiency have been addressed.
The aim of this study was to study the elasticity of the arterial wall using a non-invasive laser Doppler measurement system. The elasticity of the arterial wall is described by its compliance factor, which can be determined when both blood pressure and the radial velocity of the arterial wall are known. To measure radical velocity we used a self- mixing interferometer. The compliance factors were measured from six healthy volunteers, whose ages were varied from 21 to 32. Although a single volunteer's compliance factor is presented as an example, this paper treated the volunteers as a group. First, the elastic modulus, which is inversely proportional to the compliance factor, was determined. Then, an exponential curve was fitted into the measured data and a characteristic equation for the elastic modulus of the arterial wall was determined. The elastic modulus was calculated at different pressures and the results were compared to the static incremental modulus of a dog's femoral artery. The results indicate that there is a correlation between human elastic and canine static incremental modulus for blood pressures varying from 60 to 110 mmHg.
A modular Fourier transform spectrometer for the near infrared (NIR) wavelength region was designed and built. The work was motivated by the need for a versatile, economical and a dedicated instrument for research in the area of noninvasive diagnostics. The spectrometer uses a thermo- electrically cooled InGaAs detector for maximum sensitivity and CaF2 lenses for maximum transmission in the NIR region. Great attention was put to ensure that each element was designed and/or chosen to provide maximum sensitivity in the NIR region. The first part of the paper discusses the spectrometer design procedures, which include the design of detector optics, collimating optics, interferometer optics as well as the signal processing electronics and motion control. The second part focuses on performance evaluation and quantification of errors including detector noise, digitization noise and sampling errors. For measurements of water absorption, spectral signal-to-noise ration of ~ 50000 was demonstrated over 150cm-1 wavenumber range. Instrumentation sensitivity was found to be limited by interferogram data sampling noise.
Noninvasive blood glucose monitoring is a long pursued goal in clinical diagnostic. Among several other optical methods, near infrared absorption spectroscopy is the most promising one for the noninvasive application to date. However, realization has not been achieved. A major obstacle is the low signal-to-noise ration pertinent to physiological blood glucose measurement using the near infrared absorption technique. Sensitivity analysis of aqueous glucose absorption signals was performed in the combination band region and in the first-overtone region. The analysis involved quantification of both glucose absorption signal and the corresponding spectral noise within a particular wavelength region. Glucose absorption band at 4430cm-1 (2257nm) in the combination band region was found to give an order of magnitude higher signal-to-noise ratio than the strongest band in the first-overtone region. A Fourier- filtering algorithm was applied to the raw absorbance data to remove some of the unwanted spectral variations. With simple peak-to-peak analysis to the Fourier-filtered absorbance data, repeatability of less than ±0.5mmol/L was achieved. In addition, effects of temperature variations on the absorption spectra were studied. The effects of sample temperature were compensated with the application of the Fourier filter.
The aim of this work was to find out to which degree Tanakan affects the microcirculation parameters and the malonic dialdehyde level as a parameter of intense lipid peroxidation in insulin-independent diabetes patients with different disease durations. We used computerized capillaroscope GY-0.04 designed by the Centre for Analysis of Substances, Russia for the non-invasive measurement of capillary blood velocity as well as the size of the perivascular zone and density of blood aggregates and lipid inclusions. The microcirculation parameters were studied in two groups of insulin-independent diabetes patients. The basic group included 58 patients (61±9,0 years, disease duration 14,7±7,8 years). The patients had late diabetic complications as retinopathy and nephrophathy, neuropathy, confirmed by clinical and tool investigation. In this group we also studied the level of serum malonic dialdehyde, as a parameter of intense lipid peroxidation. The reference group included 31 patients (57±1,3 years, disease duration 3,6±0,6 years) with minimum diabetic complication. We show that Tanakan in daily dosage 120 mg for 2 months reduces the malonic dialdehyde level in the blood serum and the erythrocyte membranes of type II diabetes patients and improves the microcirculation parameters. There are correspondences between the density of lipid inclusions as determined with computerized capillaroscopy and the lipid exchange parameters as determined using a routing blood test. Thus, noninvasive blood lipid quantification is feasible and reliable.
This paper presents the experimental setup and preliminary results of a CCD based Photoplethysmographic Imager (PPGI) which has been shown to be capable to assess various disorders of the peripheral venous system by standard test methods derived from the classical photophethysmographic practice in a noninvasive and non-contact way. The PPGI is a computer- based CCD imaging system to visualize the skin vessels and analyze the local changes of dermal blood volume. Our results show that this system performs as well as the currently available commercial PPG system by adding information of spatial distribution which allows the investigation of locations and causes of vascular disorders. Both the venous hemodynamics and arterial perfusion can be mapped in two dimensions.
Development of efficient analytical and numerical techniques for the determination of optical parameters of biotissues on the base of measured data is a crucial part of successful implementation of non- invasive diagnostic techniques in clinical conditions. Widely used approximations, like diffusion approximation (DA), were shown to fail in most real-life circumstances due to simplifications of modeling or neglect of various involve phenomena, like boundary effects, tissue inhomogeneity, skin roughness and deviations of optical properties of skin in time due to physiological effects. In this work we compare experimental results with results of numerical simulations. For our measurements, we used both spatial-resolved and frequency-domain techniques. To describe propagation of photons we numerically solved the radiatve transfer equation (RTE). We found that the Monte-Carlo method (MC) is too time-consuming for large source- detector separations. We achieved flexibility in preparation of experimental medium with tissue simulating sample containing several homogeneous layers. Our objective is the investigation of accuracy in determining unknown structures and optical coefficients from measured data, based on the realistic model of the tissue described in the RTE.
In this paper we report the results of in vitro and in vivo experiments that were performed using the laser Doppler measuring system to investigate a quasiellastic light scattering from narrow blood capillaries located on the scattering background. We have shown the influence of multiple scattering on Doppler, frequency shift power spectrum.
The new technology of computerized morphometric image analysis of platelets on blood smears was developed. In a basis of the device is included analysis of cytophotometric and morphometric parameters of platelets. Geometrical and optical parameters of platelets on 35 donors, platelet concentrates and 15 patients with haemorrhagic thrombocythaemia were investigated, average meanings for the area, diameter, its logarithms and optical density of platelets in norm were received. Distribution of the areas, diameters and optical densities of platelets of patients with haemorrhagic thrombocythaemia differed from those at the healthy people. After a course of treatment these meanings came nearer to normal. The important characteristics of platelets in platelet concentrates after three days of storage were in limits of normal meanings, but differed from those in whole blood platelets. Obtained data allow to enter the quantitative standards into investigation of platelets of the healthy people and at various alteration of thrombocytopoieses.
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%.
The report describes the instrument ASPBS (Automated Screening of Peripheral Blood Cells) designed for an automated analysis of dry blood smears. The instrument is based on computer microscopy and uses dry blood smears prepared according to the standard Romanovskii-Giemza procedure. In comparison with the well-known flow cytometry systems, our instrument provides more detailed information and offers an opporunity of visualizing final results. The basic performances of the instrument are given. Software of this instrument is based on digital image processing and image recognition procedures. It is pointed out that the instrument can be used as a fairly universal tool in scientific research, public demonstrations, in medical treatment, and in medical education. The principle used as the basis of the instrument appeared adequate for creating an instrument version serviceable even during space flights where standard manual procedures and flow cytometry systems fail. The benefit of the use of the instrument in clinical laboratories is described.