Acoustic methods of reagentless medical laboratory diagnostics

Acoustic methods of non-reactive medical laboratory diagnostics based on precision measurements of sound velocity and attenuation in biological fluids are discussed. These parameters are determined at different frequencies and at different fluid temperatures using high-quality resonators. The developed methods are implemented in the measuring acoustic analyzer “BIOM”. The device contains two ultra-small ultrasonic resonators (about 100 µl) in volume. The microprocessor system of the device controls two ultrathermostats and maintains temperatures in the resonators in the range (20–38)° C with an accuracy of ± 0.005° C. The developed special software makes it possible to determine the acoustic characteristics (speed and absorption of ultrasound) in blood serum, whole blood and plasma with a relative error of ± 5×10⁻⁴ in terms of ultrasound velocity and ± 10⁻² in terms of ultrasound absorption. This made it possible to determine the total protein, protein fractions, parameters of the lipid spectrum and apolipoproteins A₁ and B, as well as the elastic properties of patients' erythrocytes in vitro.