SU1156635A1 - Apparatus for investigating motor activity of biological objects - Google Patents

Abstract

A DEVICE FOR STUDYING MOTOR ACTIVITY OF BIOLOGICAL OBJECTS, comprising a generator connected to an AC bridge, a large-scale amplifier and a recorder, characterized in that, in order to increase the accuracy of research, it is equipped with a differential amplifier, two transformers, a primary winding of one of which is equipped with a differential amplifier, two transformers, a primary winding of one of which is equipped with a differential amplifier, two transformers, a primary winding of one of which, one of them, one of which of them will be equipped with a differential amplifier, two transformers, a winding of the research, one of them will be equipped with a differential amplifier, two transformers, a winding of one of which will be equipped with a differential amplifier, two transformers. the comparative shoulder of the AC bridge, and the primary winding of the other is with the measuring arm of the AC bridge, to the secondary windings of each transformer Pa connected respectively series-connected detector, made on precision diodes, and an integrator, and the integrator outputs are connected to the inputs (L of a differential amplifier, the output of which is connected to a recorder through a large-scale amplifier.

Description

ate

Od CO. From the Invention relates to medical engineering, namely to devices for studying the physiological characteristics of biological objects in conducting media. The purpose of the invention is to increase the accuracy of the study. The drawing shows the block diagram of one independent measuring channel. The device contains a generator power supply 1, a generator 2, an AC bridge 3, isolation transformers 4, precision diodes 5, integrators 6, a power source 7 common to all terminal stages of all channels: B, differential amplifier 8, variable bridge balance indicator 9 current, scale amplifier 1Q, recording device t1. The device works as follows. The AC bridge 3 of each independent channel is powered by its generator 2 and power supply 1. The measuring arm of bridge 3 includes sensor electrodes (not indicated), which in turn are fixed on the animal to be erected or its moving organs (parts). The voltages from the comparative and measuring bridge 3 are fed to isolation transformers 4. The signals from the secondary coil of transformers 4 fall on the balancing system of bridge 8 of alternating current, where they, rectified by precision diodes 5, go to integrators 6 and then to the inputs the differential amplifier 8, the output of which receives the difference in the amplitude values of the voltages in the comparative and measuring arms of the AC bridge 3. The bridge is balanced by a variable resistor in the comparative shoulder of the bridge along the zero axis 9. All further changes in the conductivity of the measuring arm of bridge 3 are caused by the movement of the sensor electrodes attached to a biological object or the movement of organs between other electrodes included in the measuring arm of the model (salinity sensors, light temperatures, flow rates, etc.), create a constant voltage on the output of the scale amplifier 10 Depending on the tasks to various recording devices 11. At study biological objects is secured sensor electrodes (the shape and size of the electrodes due to the study, type and size of the animal) connected to the measuring arm of the bridge 3 thin light conductors (link). Due to the fact that the metal of the sensors is immersed in a conductive medium (electrolyte), the metal is polarized, and a double electric layer is formed at the metal – medium interface. With the passage of alternating current between the electrodes of the sensor, such a layer exhibits the properties of capacitance. The polarization potential, which determines the capacitance, depends on the maternity (ala (precious metals have the lowest polarization potential), the shape of the electrodes. Thus, in the measuring arm of bridge 3, the sensor has complex resistance. The complex resistance of the medium causes a phase shift in the measuring shoulder of bridge 3 AC, which makes it difficult to balance on a zero level. Compensation for phase shift in the measuring arm of bridge 3 requires the introduction of LAYERS 31 and R (1 ed phase-shifting devices. However, in specific biological For example, to study the motor activity of different species of animals, certain sensor constructions are required. For example, to study the marine activity of the scallop, sensors are used in the form of two steel plates fixed on the flaps of its ravokin. Another form of sensors - thin tungsten needles are used to register the heartbeat of this mollusk. their material; the length of their communication link with the equipment may vary in-band, & therefore, it is necessary to rebuild the phase shift of the device of bridge 3 in a particular case. The proposed balancing scheme of bridge 3 avoids such difficulties. The scheme works as follows.

3

The voltages from the comparative and measuring arms of the bridge 3 are fed to the transformer 4 each time to the balancing circuit of bridge 3. The signals from the secondary windings of the transformer 4 are rectified by small signal diodes 5 and integrated into integrators 6. Small signal diodes 5 are used because of The fact that conventional diodes exhibit properties of diodes with voltages higher than 0.3-0.7 V, while small-signal diodes implemented on operational amplifiers operate at voltages lower than 1 mV. Thus, with the introduction of low-signal (precision) diodes 5 and integrators 6, the ac bridge 3 is a highly sensitive measuring dc bridge. Constant voltages from the arms of bridge 3 are fed to the inputs of differential amplifier 8 and subtracted. At the output of differential amplifier 8, a constant error signal is received, now the weft is not dependent on the phase shift of the voltage in the measuring arm of bridge 3, and the rotation of the variable resistor knob the comparative shoulder of bridge 3 is balanced at the zero level.

One of the main purposes of the proposed device is the modern registration of the motor activity of several animals. For this, sensors mounted on animals must be electrically not connected, i.e. should not affect the work of one another. Therefore, use the following one p1n tfnem galvanic development | channels. Generators 2, supplying measuring bridges 3 with sensors in iz566354

The measuring arm has galvanically unrelated power supply units, each of them has its own winding on the power transformer 4, 5, which allows to avoid direct electrical connection between sensors of different channels (power sources can be of battery type).

10 When connecting recording equipment, such as the four-channel H-338-4P recorder, to the output of the channels, galvanic communication occurs between them, since the average

5 -: their feeding points are connected to the common ground of the recorder. To avoid this, use transform; tori 4, which galvanically dissipate each generator 1 and

20 bridge 3 from subsequent cascades. Subsequent cascades of all channels (small-signal diodes 5, differential amplifiers 10, zero-indicator 9) are powered from their power source 7, which is not galvanically connected to the power source 1 of the generators, which also has a corresponding on / power transformer-4. The midpoints of the sources t and 7 of the power supply are also isolated from one another. Thus, only the simultaneous use of these two methods completely eliminates the galvanic coupling between the sensor channels, which allows us to conduct independent simultaneous recording of motor activity of animals.

The specific devices were made on the basis of a measuring bridge of the forward current using the power unit of the type (UC) of the type UL1B1B and

iMA725.

Claims (1)

DEVICE FOR RESEARCH OF MOTOR ACTIVITY OF BIOLOGICAL OBJECTS, containing a generator connected to an AC bridge, a scale amplifier and a recorder, characterized in that, in order to increase the accuracy of the study, it is equipped with a differential amplifier, two isolation transformers, the primary winding of one of which is connected to the comparative arm of the AC bridge, and the primary winding of the other with the measuring arm of the AC bridge, to the secondary windings of each transformer by Keys respectively serially connected detector arranged on precision diode, and an integrator, wherein the integrator outputs are connected to inputs of a differential amplifier whose output is coupled through a scaling amplifier with the registrar. Ym SL Od 00 SL 1 1156635 2