METHOD FOR VISUALISING CUTANEOUS BLOOD FLOW VARIATIONS IN EXTREMITIES

摘要

FIELD: medicine.;SUBSTANCE: thermal imaging camera is used to determine skin temperature and its time variations. Temperature variations determined in each point of a thermal image of the extremity are broken down into spectral components with using mathematical wavelet transformation. Each spectral component frequency f is shifted to a previous moment of time by an interval Δt determined by formula $\Delta t_{\text{PHASE}}(f_i,z)=z/\left(2\cdot \sqrt{\frac{\pi \cdot \lambda }{c\cdot \rho }\cdot f_i}\right),\mathop{\mathrm{image}}$ wherein z is a thickness of biotissue layer, λ is a skin conductivity coefficient, c is a specific thermal capacity of skin, ρ is a skin density, f_i is a frequency of the i-th spectral component. Amplitude of each spectral component is multiplied by a coefficient determined by formula $C_{AMP}(f_i,z)=\exp \left(z\cdot \sqrt{\frac{\pi \cdot c\cdot \rho }{\lambda }\cdot f_i}\right).\mathop{\mathrm{image}}$ That is followed by reverse wavelet transformation of spectral components in each point of the thermal image to produce a resultant data array representing the blood flow variations distribution.;EFFECT: enlarging the examined surface area of the object and providing more accurate measurement of the peripheral blood parameters by temperature methods by using a new model of temperature signal propagation in biological tissue and visualising the spatial blood flow variations.;2 cl, 6 dwg, 1 tbl