Analysis of chaotic and noise processes in a fluctuating blood flow using the Allan variance technique.

OBJECTIVE: The aim of this work was to develop a novel technique for digital processing of Doppler ultrasound blood flow sensor data from noisy blood flow velocity waveforms. METHODS: To evaluate the fluctuating blood flow parameters, various nonlinear dynamics methods and algorithms are often being used. Here, for identification of chaotic and noise components in a fluctuating coronary blood flow, for the first time the Allan variance technique was used. Analysis of different types of noises (White, Brownian, Flicker) was carried out and their strong correlation with fractality of time series (the Hurst exponent) was revealed. RESULTS: Based on a specialized software realizing the developed technique, numerical experiments with real clinical data were carried out. Recommendations for identification of noisy patterns of coronary blood flow in normal and pathological states were developed. CONCLUSION: The methodology gives us the possibility for the more detailed quantitative and qualitative analysis of a noisy fluctuating blood flow data.

Water status and LPO in rat tissues during massive blood loss and irradiation with He-Ne laser.

We revealed a relationship between water balance and LPO in the myocardium, liver, and blood plasma during massive blood loss and irradiation with He-Ne laser. Low-intensity laser irradiation of the plasma inhibits LPO and normalizes water balance in rat tissues during massive blood loss.

[Effects of perftoran on experimental acute intestinal ischemia]. / Issledovanie éffektov perftorana na modeli ostroi intestinal'noi ishemii.

The studies were carried out on 76 albino noninbred male rats weighing 210-420 g. Ischemia of a jejunal segment was induced by applying a tourniquet to the base of a loop with the mesentery until the circulation fully stopped. Nonoxygenated perfluorane (an experimental group) or saline solution (a control group) was injected in a dose of 0.8-1.0 ml/100 g intraarterially 15 minutes before the termination of ischemia. During 90 min of reperfusion, there was a progressive decline of blood pressure (BP) with reference to the ischemic period by 39.8 +/- 20.9 and 20.8 +/- 14.6% in an experimental and control groups, respectively (p > 0.05). Biomicroscopy indicated that by min 5 of reperfusion, a relative reduction in the diameter (50-400 microns) of nutrient mesenteric arteries was half as large as that in the control group (24.0 +/- 5.5 and 45.1 +/- 3.6%; p < 0.05); by min 90, differences decreased (41.5 +/- 4.2 and 50.3 +/- 2.8%, respectively; p > or = 0.05). In the experimental group, perfluorane prevents the development of irreversible structural changes in the reperfusion period: the remaining cryptal epithelium is a source of regeneration of the integumentary epithelium of forming villi of the small intestinal mucosa.