METHOD OF NON-INVASIVE MEASUREMENT OF FRACTIONAL WATER CONTENT IN HUMAN BLOOD Russian patent published in 2023 - IPC A61B5/1455 G01N21/27 G01N33/49 

FIELD: medicine.

SUBSTANCE: invention relates to a method of non-invasively measuring the fractional water content in human blood. Light sources are used to alternately irradiate the area of the human body selected as the measurement object. Radiation passes through the object and hits the receiver-detector. Next, the radiation intensity measurement signals are transmitted to the processor to calculate the water content in human blood. Two laser diodes with spectral intervals of 1,420±20 nm and 1,250±20 nm are used as light sources. The proportion of water in the blood is determined using a mathematical formula. The selected measurement object is a plane-parallel continuous area of the human body that has a pronounced blood pulsation with a thickness not exceeding 0.5 cm. The thickness of the measurement object is set using a device in the form of a clothespin so that its mechanical pressure on the measurement object does not exceed the blood pressure in the vessels, by compressing the measurement object with a force calculated as the product of this pressure times the area of contact between the measurement object and the jaws of the clothespin.

EFFECT: increase in measurement accuracy is achieved with the possibility of minimizing the size and composition of the measuring device and simplifying the measurement and calculation model.

1 cl, 2 dwg