a digital analyzer
V.K. Ignatiev, A.V. Nikitin, S.V. Khramov
Osmotic resistance of erythrocytes is indicators that reflect the profound changes in the human body. Method erythrograms can be of great help in studying of this characteristic. This method is based on a linear dependence between the concentration of erythrocytes and the optical density in a given range, and consists in the photoelectric recording of hemolysis kinetics under standard conditions. The erythrogram shows the state of the blood forming and blood destroying systems, and the physicochemical conditions of the vascular system. To obtain practical erythrograms in a medical laboratory requires a lot of the preliminary procedures (sterilization tubes, dilution of solutions, temperature control, etc.). To standardize the experiments, exclude the subjective factors, and increase the rate of analysis, at the present time automatic recording of the erythrograms have been developed. This highly specialized apparatus allows obtaining erythrograms in «percent of erythrocytes - time» coordinates.
Measurement results are displayed on a large graphic LCD (240 by 128 pixels). Under the protective cover is easily removable sample compartment, containing specially designed for this device mixing device. The mixing is carried out reciprocating cell. Also in the sample compartment is placed an optical system that produces photometric study has blood. The source of light radiation is a laser module with integrated current source and the lens focusing (wavelength - 650 nm). Low angular divergence of the laser beam and monochromatic radiation from allow doing without a complex optical system. Detector is a photodiode. Then the signal proportional to the light flux passing through the test solution, amplified and digitized using the built-in ADC of the microcontroller. After this, the microcontroller calculates the values for the simplex algorithm erythrograms. On the basis of these values is drawn plot. Measure of stability is the time from the beginning of hemolysis. The device also enabled to make data exchange with a computer using USB-interface. It was a comparison of the obtained erythrograms with a standard laboratory method. Errors in the testimony of typical errors caused by the method of photometry of blood and inaccuracy of manual dilution of samples. Errors in the testimony - is typical errors by the method of photometry of blood and inaccuracy of manual dilution of samples. Also were investigated statistical errors obtained erythrograms and the testimony of the device depending on the temperature test solution.