RU2348926C1 - Polarimetric tester for molecular oxygen content in homogenates of analysed tissues and method of application thereof - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention refers to experimental medicine. Polaimetric tester for molecular oxygen content in homogenates of analysed tissues includes measuring electrolytic cell, limiting resistor, contacts, measurement and control module, thermostating unit with thermoheating element, PC and controlled power unit. Measuring electrolytic cell represents glass cylinder with discharge and two electrodes, one of which is the conductive bottom and which are connected to measurement and control module and controlled power unit through contacts and limiting resistor. Besides measurement and control module is connected to thermostating unit with thermoheating element. PC is connected to controlled power unit and measuring electrolytic cell through measurement and control module, as well as to thermostating unit with thermoheating element. Furthermore testing method for molecular oxygen content in homogenates of analysed tissues is offered.

EFFECT: complete representation referring molecular oxygen content in homogenate of analysed tissues is provided with higher accuracy and stability of measurement results; possibility to store and accumulate measurement results in the form convenient for their following mathematical and analytical processing, generation of automated data gathering and processing system, maintenance of stable experiment temperature.

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Description

The invention relates to experimental medicine and is intended for measuring, processing and recording the amount of molecular oxygen in the homogenates of the studied tissues.

Known designs of polarimeters, as a rule, containing an electrolyzer, a sensor of two electrodes with their immersion in the test medium and connected to a power source (1, 2, 3, 4). Their application allows us to determine the relationship between the current strength and oxygen content in the studied tissues and to characterize the qualitative values of the electrochemical process associated with oxygen in biological tissues (1, 2, 3, 4).

The disadvantages of such polarimetric devices are

1. Low noise immunity from external electromagnetic interference.

2. The presence of a compensation electrolytic cell, complicating the process of collecting information.

3. The lack of an automatic error correction system, which is caused by the temperature instability of amplifiers.

4. The inability to store measurement results in a form convenient for mathematical and analytical processing of accumulated information.

5. Rigid logic of the system.

The disadvantages of the use of such polarimetric devices are

1. Low degree of automation process of the measuring system.

2. The lack of an automated system for processing the information received.

The technical result of the use of a device and method for measuring, processing and recording the amount of molecular oxygen in the homogenates of the studied tissues is

1. A complete picture of the molecular oxygen content in the homogenate of the studied tissue.

2. Improving the accuracy and stability of measurement results.

3. The ability to store and accumulate information about the measurement results in a form convenient for their further mathematical and analytical processing.

4. Creation of an automated system for collecting and processing information.

5. Maintaining a stable experiment temperature.

The technical result is achieved through the use of

1. A differential DC amplifier with a high input impedance of 100 kOhm, made according to an automatic balancing scheme with the possibility of suppressing impulse noise, which has a high coefficient (60 dB) of suppressing the in-phase signal of an alternating electromagnetic field caused by an extraneous radiation source (differential amplifiers described in In our literature, the designs of polarimetric devices have a common-mode signal rejection coefficient of the order of 20-30 Db, which is two to three levels lower than in proposed device).

2. The presence of automatic balancing in the differential amplifier circuit reduces the temperature instability in the measurement and control module and leads to a decrease in the value of the systematic measurement error in the molecular oxygen content.

3. PC (personal computer), carries out automated collection and processing of information received from the measurement and control module.

4. The possibilities of using a powerful mathematical apparatus of application software of various manufacturers.

5. The possibilities of a personal computer (personal computer), when storing large amounts of information.

Figure 1 presents the complete structural diagram of the proposed polarimetric device for measuring, processing and recording the amount of molecular oxygen in the homogenates of the studied tissues.

1, 2 - contacts,

3 - measurement and control module,

4 - thermo-heating element,

5-PC

6 - controlled power supply,

7 - measuring electrolytic cell (IEI),

8 - temperature control unit (BT),

9 - limiting resistor.

Figure 2 shows a more detailed block diagram of a measurement and control module 3, consisting of

3a - PSU (power supply unit of the converter amplifier);

3b - Dif. UPT (differential DC amplifier with a high input resistance of 100 kOhm);

3c - Comparator (conversion comparison module);

3G - GOCH (reference frequency generator - highly stable crystal oscillator 1 Hz / 1000 Hz);

3D - El. Key (electronic key - digital signal generation module).

The polarimetric device operates as follows:

The tissue homogenate is placed in a measuring electrolytic cell (IEI) 7. IEI 7 is a glass cylinder with a drain with a platinum wire soldered into the bottom of the glass cylinder. For better contact of the platinum wire with a solution of tissue homogenate, mercury is poured onto the bottom of IEA 7. The electrically conductive bottom created in this way makes better contact with the test solution of tissue homogenate and is the first electrode. The second electrode is a glass conductive system containing KCl, hollow inside and installed on top in IEI 7 with immersion in the liquid phase. The liquid phase of IEI 7 is a solution of Tris buffer with a specific pH and homogenate of the test tissue. We add tissue homogenate to the Tris-buffer solution at the rate of 1/10 with the obligatory automatic mixing of the contents. To reduce thermal errors in the experiment, a thermo-heating element 4 is introduced into IEI 7 to maintain a given temperature in the liquid phase of IEI 7.

At the operator’s command, the personal computer 5 includes a controlled power supply unit 6, which starts to supply a supply voltage of 2 volts to the measuring electrolytic cell (IEI) 7. Then the personal computer 5 transfers the thermostatic control unit (BT) 8 with the help of the heating element 4 to automatically maintain the temperature of the Tris solution -buffer and homogenate of tissue located in IEI 7. After that, the process of collecting and processing information received on the PC 5 from the measurement and control amplification module 3, which works as follows, is started.

An electrical signal from contacts 1 and 2 is fed to the input of a differential amplifier 36 of the measurement and control module 3, where it is amplified and cleaned of impulse and common mode noise. Next, the amplified signal is fed to the input of the conversion comparison module - comparator 3c, to the other input of which pulses of a sawtooth shape of constant amplitude and frequency (1 Hz) from a highly stable reference frequency generator - GOCH 3g are received. The process of stabilization of pulses is performed by a quartz resonator, which is part of the GOCH 3g.

Comparator 3B compares the signals of both types and the formation of rectangular pulses of variable duration of constant frequency and having the following functional dependence:

Where

T _and - the pulse duration at the output of the comparator;

U _I - voltage value, depending on the content in the measuring electrolytic cell of oxygen;

F is the pulse repetition rate. In our case, it is equal to 1 Hz.

This type of pulses controls the operation of the 3D electronic key, to the other input of which pulses of a higher frequency are applied - 1000 Hz with GOCH 3g. In the 3D electronic key circuit, two types of pulses are added, as a result of combining pulses of both types at the output of the 3D electronic key, a digital electrical signal is formed, convenient for processing on a PC 5, which carries complete information about the amount of molecular oxygen in the homogenate of the tissue under study.

The signal thus obtained is fed to the input of the PC 5, where it is subjected to preliminary mathematical processing and stored in the form of a file on the hard disk. After completion of the operation, the device is turned off by a controlled power supply 6. The experiment time is set on the PC 5.

After the experiment, the stored information can be subjected to mathematical processing and presented in the form of tables, graphs in accordance with the goals and objectives of the experiment. The processed information gives a complete picture of the molecular oxygen content in the studied object.

The proposed polarimetric device for measuring, processing and recording the amount of molecular oxygen in the homogenates of the studied tissues has the following technical characteristics:

time of one measurement 1 second;

input sensitivity of the measuring complex is 10-15 mV per 1% molecular oxygen;

measurement accuracy not less than 1%;

minimum process registration time 1 minute;

the maximum registration time depends on the characteristics of the personal computer and is limited by free space on the hard drive;

supply voltage 220 V 50 Hz.

The system has the ability to remotely transmit information through any known information communication channel (cellular channel, telephone channel, etc.).

Example.

The homogenate of the test tissue is immersed in an electrolytic cell.

At the operator’s command, the personal computer 5 includes a controlled power supply unit 6, which starts to supply a supply voltage of 2 volts to the measuring electrolytic cell (IEI) 7. Then, the personal computer 5 switches the thermostatic control unit (BT) 8 to the mode of automatically maintaining the temperature of the test solution of tissue homogenate located in IEEA 7. After that, the process of collecting and processing information coming to PC 5 from the measurement and control module 3 is started. The experiment time is set on PC 5 depending on the purpose of the experiment.

The signals are fed to a PC 5 from the measurement and control module 3, where in a differential DC amplifier with a high input resistance of 100 kOhm 3b, the signals are amplified, they are cleaned of impulse and common-mode noise, and their further supply to the comparison circuit is comparator 3c. To the other input of the comparator 3c, sawtooth pulses of constant amplitude and frequency (1 Hz) from a highly stable reference frequency generator (GOCH) 3 g are received. In the comparator Sv, signals of both types are compared and then the formation of rectangular pulses of variable duration of constant frequency. This type of impulses determines the operation of the electronic key (El. Key) 3D. At the input of the electronic key (El. Key) 3D pulses of a higher frequency of 1000 Hz are supplied from the reference frequency generator (GOCH) 3G. In the electronic key circuit (El. Key) 3d, rectangular pulses of variable duration of constant frequency are added, formed in the comparator Sv and pulses of a higher frequency of 1000 Hz from the reference frequency generator (GOCH) 3g. As a result of combining 3D pulses of both types in the electronic key (E-Key) 3D, an electronic digital signal is generated at the output of the electronic key (E-Key) 3D, convenient for processing on PC 5, where it is processed and stored on the hard disk in a mathematical program as a file.

During the experiment, the PC screen 5 reflects the time of the study, as well as the temperature of the liquid phase in the measuring electrolytic cell (IEI) 7.

The stored information about the content of molecular oxygen in the form of a file on the hard disk after mathematical processing is then converted into tables, graphs.

Figure 3 shows a graph indicating the content of molecular oxygen in the homogenate of the test tissue. On the ordinate axis, the abbreviation "molecular oxygen concentration in micromoles" indicates the concentration of molecular oxygen, expressed in micromoles, and the abscissa axis under the abbreviation "experiment time in seconds" defines the experiment time. By a graphical representation of the molecular oxygen content in the homogenate of the tissue under investigation, we can also trace the dynamics of changes in the molecular oxygen content in the tissue under investigation at several points.

In the polarimetric device for measuring, processing and recording molecular oxygen content in the homogenates of the studied tissues and the method of its application, a more advanced circuitry solution is used, made on the basis of a differential DC amplifier with a high input impedance of 100 kOhm with an integrated system for suppressing pulse and common-mode interference of a higher class , wherein

1. The measuring amplifier has an automatic balancing system that allows to minimize the systematic measurement error caused by temperature fluctuations associated with the environment and the heating of the elements of the electronic circuits of the conversion amplification module.

2. Automated the process of collecting and processing data through the use of PCs.

3. It has become possible to use the power of the mathematical apparatus of modern application software.

Literature

1. O.A. Aleshin. Chemical analysis. - L .: Nauka, 1954. - P.43.

2. E.A. Kovalenko, V.A. Berezovsky, I.M. Epstein. Polarographic determination of oxygen in the body. - M.: Medicine. - 1975 .-- 230 s.

3. Guidelines for the study of biological oxidation by the polarographic method. - M .: Science. - 1973, - 220 s.

4. R.M-F.Salikhjanova, G.I. Ginzburg. Polarographs and their operation in practical analysis and research. - M .: Chemistry. - 1988. - 160 p.

Claims (2)

1. A polarimetric device for determining the molecular oxygen content in the homogenates of the studied tissues includes an electrolytic cell, a limiting resistor, contacts, a measurement and control module, a temperature control unit with a thermo-heating element, a personal computer (PC), a controlled power supply, characterized in that the measuring electrolytic cell is made in the form of a glass cylinder with a drain and two electrodes, one of which is an electrically conductive bottom (platinum a wire, soldered to the bottom of a glass cylinder with a drain and mercury in contact with it), which are connected through contacts and a limiting resistor to a measurement and control module and a controllable power supply, a temperature control unit with a thermal element is also connected to the measurement and control module, and a PC through a measurement and control module it is connected to a controlled power supply unit and a measuring electrolytic cell, a PC connected to a measurement and control module is also connected to a thermostatic unit anija and termonagrevayuschim element. 2. A method for determining the molecular oxygen content in the homogenates of the studied tissues, including the registration of signals from the measuring electrolytic cell, their collection, sorting, processing and storage in real time using a PC, characterized in that the signals are transmitted to the PC from the measurement and control module, where in a differential DC amplifier with a high input impedance of 100 kOhm, made according to the automatic balancing scheme, it is possible to suppress pulsed interference with a high coefficient (60 dB) suppression of the in-phase signal of an alternating electromagnetic field, at the same time, the signals are amplified, cleared of impulse and in-phase noise, and then fed to a comparison circuit - a comparator, which also receives sawtooth pulses of constant amplitude and frequency (1 Hz) from a highly stable the reference frequency generator, where the pulse stabilization process is performed by a quartz resonator, the comparator compares both types of signals with the subsequent formation of a rectangular shape at the output of the pulses s of variable duration of constant frequency, from the reference frequency generator to the input of the electronic key pulses of a higher frequency are applied - 1000 Hz, where in the future the rectangular pulses of variable duration of constant frequency formed in the comparator and pulses of a higher frequency of 1000 Hz going from a reference frequency generator, combining pulses of both types in an electronic key at the output generates a digital signal, convenient for processing and saving on a hard disk as a file on a PC.

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