RU1821129C - Rotary blood viscometer - Google Patents

Description

The invention relates to medical equipment and can be used to determine blood viscosity in the diagnosis of diseases associated with theorheological changes, for example, with hypertension, myocardial infarction, atherosclerosis, diabetes, with anemia, etc.

The purpose of the invention is to reduce the time for determining blood viscosity at a given shear rate.

The invention is illustrated in the drawing.

The installation consists of a fixed thermostatically controlled outer cylinder 1, an internal free-floating cylinder 2, and a block for rotating the inner cylinder, which contains a series-connected generator 3, a multiplier 4 and a first power amplifier 5 connected to the first input of the stator of the motor b, while the output of the multiplier 4 through a phase shifter 7 and a second power amplifier 8 connected to the second input of the stator 6, contains a serially connected signal shaper 9, an integrating adder 10, a quadrator 1.1 connected to dividend input of the divider 12, the divider 12 via an analog-to-digital. the converter 13 is connected to the indicator 14, while the output of the integrating adder 10 is connected to the switch 15 and the second input of the multiplier 4, contains a reference voltage source 16 connected in series, a shear rate adjuster 17 and a digital-to-analog converter 18, while the reference voltage source 16 is connected to by a signal shaper 9, and the output of the digital-to-analog converter 18 is connected to the second input of the integrating adder 10 and to the second input of the divider 12, and also contains a photoelectric tachometer 19, connected outputted with a signal conditioner 9 and through a one-shot with a restart 2.0 with a control input of the switch 15.

The principle of operation of the viscometer is based on maintaining a given rotation speed of the inner cylinder 2 and determining the viscosity by the magnitude of the voltage across the stator windings of the engine 6 at a given rotation speed.

Generator 3 generates a sinusoidal voltage to power the stator of motor 6. Multiplier 4 changes the amplitude of the signal in proportion to the output voltage of integrating adder 10. Phaser 7 shifts the phase of the sinusoidal signal to create a rotating magnetic field in the stator of the motor B. 5.8 power amplifiers provide

the required value of the operating current in the stator windings of the motor 6.

The photoelectric tachometer 19 generates a pulse signal whose frequency is proportional to the speed of rotation of the inner cylinder 2. The signal shaper 9 normalizes the pulses in duration and amplitude, so that a sequence is formed at its output

0 pulses of equal duration, the repetition rate of which is proportional to the rotation speed of the inner cylinder 2, and the amplitude is equal to the voltage of the reference voltage source 16. These pulses are fed to the input of the integrating adder tO. A negative voltage is supplied to the other input of the integrating adder 10 from the output of the digital-to-analog converter 18, which corresponds to the set shear rate at the shear rate adjuster 17. This voltage is stabilized by the reference voltage source 16. Thus, the integrating adder 10.

5 generates a signal proportional to the integral of the difference of the two signals arriving at its inputs.

When installing, the inner cylinder 2 generates the first pulse, according to which a single-shot is triggered with a restart 20, which opens the switch 15, since the shear rate is specified on the shear speed controller 16, then the output of the digital-to-analog converter 18

5, a voltage is present, and the voltage at the output of the integrating adder 10 will begin to increase. The signal at the output of the multiplier 4 and, accordingly, on the stator windings of the motor 6, will also begin to increase.

0 as the voltage increases, the inner cylinder 2 begins to rotate, and the driver 9 begins to generate pulses. When the time-average value of these pulses is compared with the value at the output of the DAC 18, the output voltage of the integrating adder 10 will stop growing and this voltage will correspond to the viscosity of the measured liquid. This voltage is squared by a square 11, the divider 12 is divided by the value of the shear rate and the value is proportional to the viscosity, which is converted by the ADC 13 and displayed on the indicator 14.

5 After the inner cylinder 2 has been removed, the pulses will cease to be fed to the input of the photoelectric sensor 19 and after 20-30 seconds the one-shot with restart 20 closes the switch 15, while through the multiplier 4 the stator is de-energized and the device goes into standby mode for the next measurement .

The proposed device makes it possible to determine the viscosity of a blood sample for a given shear rate for 30 s. To measure the viscosity for the same shear rate using the prototype, it is necessary to make a series of measurements in order to set the predetermined rotation speed of the inner cylinder by successive approximations, i.e. it is necessary to make 5-10 measurements, which will take a corresponding number of times more time ...; - ...: - ..-. .. . .

A rotational blood viscometer can be used in hematology, endocrinology, cardiology and other fields of medicine, as well as in the analysis of other liquids with a viscosity of 1-20 cLs at shear rates from f to 200 Cv.

Claims (1)

SUMMARY OF THE INVENTION A rotational blood viscometer comprising a stationary thermostatically controlled outer cylinder, an inner cylinder and a block for rotating the inner cylinder, so that, in order to reduce the time for determining the viscosity at a given shear rate, a block for rotating the inner cylinder 10 T5 0 5 0 contains a series-connected generator, multiplier and a first power amplifier, the output of which is connected to the first input of the stator of the motor, while the output of the multiplier through a phase shifter and a second power amplifier is connected to the second input of the stator, contains a series-connected signal shaper integrating an adder, a quadrator whose output is connected with the input of the divisible divider, the output of which through an analog-to-digital converter is connected to the indicator input, while the output of the integrating adder is connected Connected to the switch and the second input of the multiplier, it contains a series-connected reference voltage source, a shear rate adjuster and a digital-to-analog converter, while the output of the reference voltage source is connected to the first input of the signal conditioner, and the output of the digital-to-analog converter is connected to the second input of the integrating adder and to the second the divider input, and also contains a photoelectric tachometer, the output of which is connected to the second input of the signal conditioner and through a one-shot with restart with switch control input.