METHOD FOR NON-INVASIVE DETERMINATION OF THE CONTENT OF WATER IN BLOOD AND BIOLOGICAL MEDIA Russian patent published in 2022 - IPC A61B5/00 A61B5/22 

FIELD: medical equipment.

SUBSTANCE: in the method for non-invasive determination of the content of water in blood and biological media three sources of infrared emission are used — laser diodes in the super-luminescent mode with the following spectral intervals: 1,300±30 nm, 1,380–1, 440 nm, and 1,550±30 nm. The emission intensity signals are measured alternately for all sources of light incident on the object J₀ and absorbed in the object J. The mathematical model for programming the processor is based on analytical formulas. k=-(L*)^-1ln(J/J₀K₀) is the general formula for calculating the absorption coefficient k in an object based on the measured signal parameters. K₀=J_meas1/J₀₁ is the correction coefficient taking into account non-absorbing light losses and measured using a first source in the spectral window of water transparency; L*=-k_w2^-1ln(J₂/J₀₂K₀) is the standardised optical path length measured using a second source in the spectral interval with total absorption by water; c_w=(k₃ - k_ck3)/(k_w3 - k_ck3) is the formula for the concentration c_w of water in the object, calculated based on measurements and calculations of the absorption coefficient k₃ in the object using a third source and measured or previously found absorption coefficients in the spectral range of a third source — water k_w3 and associated components k_ck3.

EFFECT: simplified technique of measurements and calculations, improved accuracy of measurements.

1 cl, 5 dwg