METHOD OF MEASURING BLOOD FLOW RATE Russian patent published in 2017 - IPC A61B5/05 G01P5/26 G01P5/01 

FIELD: measuring equipment.

SUBSTANCE: invention relates to measuring equipment and concerns a method of measuring flow rate of a fluid with light-scattering particles. Method involves illuminating the fluid flow simultaneously with two beams of laser radiation and determining power spectrum P₁₂(f) of the reflected signal. Then the fluid flow is illuminated with each beam of laser radiation separately and determined are power spectra P₁(f) and P₂(f) of the reflected signals when been illuminated accordingly with the first and the second radiation beam. Extracted from the power spectrum are frequency components P'₁₂(f) corresponding to the light scattering on particles illuminated simultaneously with two beams of laser radiation: P'₁₂(f)=P₁₂(f)-P₁(f)-P₂(f). From the extracted frequency components determined is frequency f_d of the power spectrum maximum. Fluid flow rate is calculated by formula u=λ₀/(2n sin(α/2)cosβ)f_d, where λ₀ – wavelength of the laser radiation, n – refraction index of the medium, in which measured is angle α between the laser beams, β – angle between directions of blood velocity u and differential wave vector K, where K=k_i1-k_i2, where k_i1 and k_i2 – wave vectors of the first and the second beams of laser radiation, respectively.

EFFECT: technical result is providing high signal/noise ratio when measuring flow rate of strongly scattering fluids and accuracy of the measurements.

1 cl, 12 dwg