SU1386905A1 - Photoelectric hemoglobin meter - Google Patents

Abstract

The device relates to medical technology and can be used to determine the concentration of hemoglobin in the blood. The purpose of the invention is to simplify the design and increase the sensitivity of the device. The device contains a power source 1, a stabilized generator of 2 pulses, a key device 3, a sensor 4, an amplifier 8, a logarithm A1 SSC 9, a display unit 10, a source 11 of the reference voltage. 1 il.

Description

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The invention relates to medical technology and can be used in determining the concentration of hemoglobin in the blood.

The purpose of the invention is to simplify the design and increase the sensitivity of the device.

The drawing shows a functional diagram of a photovoltaic hemoglobinometer.

The hemoglobinometer contains a sensor power supply 1 in the form of a stabilized generator of 2 pulses and a key device 3, a sensor 4 in the form of an LED 5, a cell 6 and a photodiode 7, an amplifier 8, a logarithmic analog-to-digital converter 9, an indication unit 10 and a reference voltage source 11,

Hemoglobinometer works as follows.

The signals from the output of the stabilized generator 2 pulses through the key device 3 are fed to the LED 5, which emits a sequence of solar pulses passing through the branch 6 with the hemoglobin cyanide solution and falling on the surface of the photodiode 7. Such an organization allows the sensor to increase the amplitude power supply in a pulse of 5-8 times compared with the permissible value of the direct current power supply of the LED. At the same time, at a sufficiently large duty cycle (50-100), the average power consumed by the LED is 6–20 times less than at a constant current supply.

With an increase in the current in a pulse, the radiation power increases according to the exponential law

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where V 1,2-1,3;

Pjj and 1 rel. respectively, relative changes in radiation power and feed current. In view of the sufficiently high radiation power of the LED, there are no requirements for the sensitivity of the photodetector.

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In addition, there are no increased requirements for the amplifier circuit. It can be performed on a single operational amplifier with a high input impedance and does not require compensation of the zero drift, since the amplifier operates in a pulsed mode.

Claims (1)

The signal from the output of amplifier 8 is fed to the input of a logarithmic analog-digital converter 9 of the voltage ratio, to another input of which a signal corresponding to the zero concentration value is received from the source 11 of the reference voltage. To start the converter 9, the trigger pulses come from the output of the stabilized generator of 2 pulses. The scale factor of the transducer 9 is selected in such a way that its output code corresponds to the value of the detected concentration and is displayed as a number on the display unit 10. Invention Formula A photoelectric hemoglobinometer containing an amplifier, a digital display unit and a sensor, a sensor power source, characterized in that, in order to simplify the design and increase the sensitivity of the device, 3 of them are logarithmized analog-digital converter, a power source of the sensor, made in the form of serial a stabilized square-wave generator and a key device, a reference voltage source, with the output of the stabilized square-wave generator soy; Inen with control input of a logarithmic analog-to-digital converter and through a key device with a sensor input, the first input of a logarithming analog-to-digital converter is connected to the output of a reference voltage source, and the second input is connected to an amplifier output; the device, its second output is connected to the input of the digital display unit and is the output device. vniipi Order 1491/43 Circulation. 847 Random polygons pr-tie, Uzhgorod, st. Project, 4 Subscription