RU2369327C1 - Device for analysing parametres of human visual system sluggishness - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention relates to medical equipment and is intended for analysing parametres of human visual system sluggishness. Device contains generator of second pulses, RS-trigger, four univibrators, unit of 10 univibrators, four analogue commutators, three resistive dividers, two OR components, unit of 10 analogue multiplexes, unit of 10 converters voltage-pulse duration, analogue multiplexor, analogue storage device, binary counter, multiplexor, register, unit of 10 OR components, unit of 10 light sources, AND component, counter, generator of millisecond pulses, display unit, unit of 10 commutators and scrambler.

EFFECT: method allows to reduce time of analysing, due to which can be applied in mass examinations or in process of testing by bicycle ergometry for evaluation of person's tiredness degree or their functional state.

5 dwg

Description

The invention relates to medical equipment and is intended to study the parameters of inertia of the human visual system.

A device for experimental research of the time of inertia of the visual system, containing a pendulum that sets the exposure time of the brand and a set of contrast filters [1]. Using this device, the threshold contrast e is measured for an object during stationary observation, then, at different contrasts K _n created by a given set of filters, the effective contrast K _{e is} brought to the visibility threshold by selecting the exposure time t specified by the swing amplitude of the pendulum. 3a, the time of inertia of the visual system is taken as the effective time of preservation of the visual impression, and when the exposure time t <0.01 is determined by the formula:

q = K _n t / e.

A device for studying the bandwidth of a human visual analyzer based on a small PROMIN-M digital computer, including a digital display, its control units, a delay device (PP9-2 m), analysis units for the accuracy of receiving a digital signal and a memory unit [2]. As test signals use the numbers shown on digital lamps IN-1 on the electronic computer display every 7 seconds. The display shows the first number from the digital array with the exposure time set before the experiment, after which an erasing image appears on the display. The test subject recognizes each number and types it on the keyboard. The dispatcher program compares this number with the subject typed on the keyboard. The error and exposure time at which it was made is recorded.

Recognition time, that is, the time required for image recognition, depends on the inertia parameters of the visual system and is determined by the time of perception of visual information [3, 4].

Closest to the technical nature of the present invention is a device for studying the inertia parameters of the human visual system, comprising a control panel, a light source, a counter, an indicating unit, a second pulse generator, a first one-shot, element I, a millisecond-pulse generator, a second one-shot with an adjustable pulse duration , the third one-shot and the element OR, and the output of the element And is connected to the first input of the counter, the output of which is connected to the first input of the display unit , the first output of the control panel is connected to the first input of the light source, the output of the first one-shot is connected to the second input of the counter, the second input of the display unit is connected to the second output of the control panel, the output of the millisecond pulse generator is connected to the first input of the element And, the output of the second pulse generator is connected to the input the first one-shot, the output of which is connected to the first input of the OR element and to the first input of the second one-shot with an adjustable pulse duration, the output of which is connected to the second input ohm of the AND element and with the input of the third one-shot, the output of which is connected to the second input of the OR element, the output of which is connected with the second input of the light source, the third output of the control panel is connected to the second input of the second one-shot with an adjustable pulse duration [5].

A disadvantage of the known devices is the duration of the study of the inertia parameters of the human visual system. This does not allow the use of devices during mass examinations or in the process of testing by bicycle ergometry in order to assess the degree of fatigue of a person or his functional state.

The inventive device allows to reduce the research time, so it can be used for mass examinations or in the process of testing by bicycle ergometry in order to assess the degree of fatigue of a person or his functional state.

The technical result is achieved by the fact that the device contains a second pulse generator, a millisecond pulse generator, a first to third one-shot, AND element, an OR element, a counter and an indication unit, a first input of an AND element connected to an output of a millisecond pulse generator, an output to a first counter input, the output of which is connected to the input of the display unit, the output of the second pulse generator is connected to the input of the first one-shot, the output of which is connected to the input of the second one-shot and the second input of the counter, but The second one is that an RS-flip-flop, a fourth one-shot, a block of 10 one-shots, a first-fourth analog keys, a first-third resistive divider, a second OR element, a block of 10 analog multiplexers, a block of 10 voltage-to-pulse converters, analog multiplexer, analog storage device, binary counter, multiplexer, register, block of 10 OR elements, block of 10 light sources, block of 10 keys and an encoder, the output of the second one-shot connected to the S-input of the RS-flip-flop Whose R-input is connected to the output of the third one-shot, and the output - with the first inputs of a block of 10 voltage-to-pulse converters and second inputs of the second-fourth analog keys, the first inputs of the third-fourth analog keys are connected to the output of the first analog key, the first input which is connected to the output of the first OR element, the second input to the output of the analog storage device, the outputs of the second to fourth analog keys are connected respectively to the inputs of the first to third dividers equal, the outputs of which are connected respectively by the first or third inputs of a block of 10 analog multiplexers, the outputs of which are connected with the second inputs of a block of 10 voltage-pulse converters and the first inputs of an analog multiplexer, the outputs of a block of 10 voltage-pulse converters are connected to the inputs of a block of 10 single vibrators and the first inputs of the multiplexer, the output of which is connected to the input of the third single vibrator and to the second input of the And element, the output of the third single vibrator is connected also with a counting input of a binary counter and with a second input of an analog storage device, the outputs of a binary counter are connected to the fourth inputs of a block of 10 analog multiplexers and to the inputs of the first OR element, the outputs of a block of 10 single vibrators are connected to the second inputs of a block of 10 OR elements, the first input which is connected to the output of the first one-shot, and the outputs to the inputs of a block of 10 light sources, the outputs of a block of 10 keys are connected to the inputs of the encoder and the second OR element, the outputs of the encoder are connected to the first the register inputs, the output of the second OR element - with the input of the fourth one-shot, the output of which is connected to the second input of the register, the outputs of which are connected to the second inputs of the analog multiplexer and multiplexer, the output of the analog multiplexer is connected to the first input of the analog storage device.

The inventive device due to the introduction of the RS-trigger, the fourth one-shot, a block of 10 single-shots, the first to fourth analog keys, the first to third resistive dividers, the second OR element, the block of 10 analog multiplexers, the block of 10 voltage-to-pulse converters, the analog multiplexer, analog storage device, binary counter, multiplexer, register, block of 10 OR elements, block of 10 light sources, block of 10 keys and encoder can reduce the measurement time, due to which it can be used during mass examinations or in the process of testing by the method of bicycle ergometry in order to assess the degree of human fatigue or its functional state.

Thus, the claimed device differs from the known new property, which determines the receipt of a positive effect.

Figure 1 presents a structural diagram of the inventive device, figure 2 is a diagram of a resistive divider.

Figure 3 presents a timing diagram of the sequence of two light pulses presented for the study of the inertia parameters of the human visual system, where τ _and is the pulse duration equal to 50 ms; T is the repetition time of two light pulses equal to 1 s; t is the duration of the pause between two light pulses.

Figure 4 presents the time diagram of two light pulses of duration τ _and > τ ₁ separated by a pause t _p and the visual sensations caused by them, where figure 4, a is a time diagram of two light pulses separated by a pause t _p causing a visual sensation of separation impulses; figure 4, b is a timing diagram of the visual sensation of the two light pulses shown in figa; figv is a timing diagram of two light pulses separated by a pause t _cr , causing a subjective visual sensation of the merger of two light pulses into one; figure 4, g is a timing diagram of the visual sensation of the two light pulses shown in figure 4, c; τ ₁ is the time of sensation, that is, the time between the moment of exposure of light to the retina and the moment of occurrence of the corresponding visual sensation [6, 7]; τ ₂ is the recovery time, that is, the time between the moment the light stops affecting the retina and the moment the corresponding visual sensation disappears [6, 7].

Figure 5 presents the timing diagrams of the operation of the claimed device.

The inventive device comprises a 1 second pulse generator, an RS-flip-flop 2, a first-fourth one-vibrator 3-6, a block 7 of 10 one-vibrator, the first-fourth keys 8-11 analog, the first-third dividers 12-14 resistive, the first-second elements 15 -16 OR, block 17 of 10 analog multiplexers, block 18 of 10 voltage-to-pulse converters, multiplexer 19 analog, analog storage device 20, counter 21 binary, multiplexer 22, register 23, block 24 of 10 OR, block 25 of 10 light sources, element 26 AND, counter 27, gene 28 millisecond pulse generator, indication unit 29, block of 10 keys and encoder 31.

The first 3 single vibrators and block 7 single vibrators are designed to generate two light pulses of a duration of 50 ms, the second and fourth 4-6 single vibrators are used to generate short pulses. Single vibrators can be performed, for example, using the K155AG1 microcircuit, which can be triggered both on the leading and trailing edges of the incoming pulses, according to the scheme [8, Fig. 4.20, p.216].

The first and fourth switches 8-11 are designed for switching voltages and can be performed, for example, using the K564KT3 microcircuit [9, p. 39].

The voltage-to-pulse duration converters of block 18 are designed to convert the voltage into a time interval proportional to it and can be performed, for example, according to the scheme [10, Fig. 4.14, p.155], in which the self-oscillating multivibrator is replaced by a standby one.

The analog storage device 20 is designed to store voltage and can be performed, for example, according to the scheme [9, Fig. 8.17, p.240].

The remaining functional units of the structural diagram are well known or correspond to the prototype.

The device operates as follows. When the power is turned on, the RS-trigger 2, the counter 21 is binary, the register 23 and the counter 27 are reset (chains are not shown), a constant voltage is applied to the second key 9. The generator 28 generates pulses with a given frequency, arriving at the input of the And element 26 (Fig. 5, i), the generator 1 generates pulses with a frequency of 1 Hz (Fig. 5, a), arriving at the input of the first one-shot 3, which is on the leading edge of each pulse generates the first of two pulses with a duration of 50 ms (Fig.5, b). The pulses from the output of the first one-shot 3 reset the counter 27, go to the second one-shot 4 and through the block 24 of the elements OR to the light sources of the block 25 (Fig.5, e).

The second one-shot 4 at the trailing edge of the pulse from the output of the first one-shot 3 produces a short pulse that sets the RS-trigger 2 to unity (Fig. 5, c), the second switch 9 commutes the voltage from the input to the first divider 12, from the outputs of which there are ten constant voltages through the multiplexers, the analog block 17 is supplied respectively to the inputs of the multiplexer 19 and ten converters, the voltage-pulse duration of the block 18. At the output of the first converter, a pulse duration of 50 ms is formed, that is, received upper limit of the duration of the pause between two light pulses (5, g). At the output of each subsequent converter, a pulse duration is formed, reduced compared to the duration at the output of the previous converter by 5 ms. The pulses from the outputs of ten voltage-to-pulse duration converters of block 18 are supplied respectively to multiplexer 22 and single-vibrators of block 7, which produce the second of two pulses with a duration of 50 ms after the decay of pulses (FIG. 5, d), which are transmitted through the elements of OR block 24 to light sources block 25 (figure 5, e).

At the first stage, the test subject determines the light source of block 25, for which he subjectively feels the merging of two light pulses into one, and closes the corresponding key of block 30, the output signal of which goes to encoder 31 and OR element 16. The private key code from the output of the encoder 31 is sent to the register 23, the signal from the output of the element 16 OR to the fourth one-shot 6, the pulse from the output of which (Fig. 5, g) writes the private key code into the register 23.

The closed-key code from the output of the register 23 is supplied to the multiplexers 19 and 22. The pulse duration corresponding to the light source, for which the merging of two light pulses into one is subjectively felt, is fed to element 26 through the multiplexer 22. When the signal of the logical unit is at the output of the multiplexer 22, the frequency from the output of the generator 28 is supplied to the counting input of the counter 27 (Fig. 5, k), the counting result is displayed on the indicators of the display unit 29.

At the same time, the voltage corresponding to the light source, for which the fusion of two light pulses into one is subjectively felt, from the output of the multiplexer of block 17 through the multiplexer 19 is fed to the device 20 analog storage, which is recorded by a pulse from the third one-shot 5 (Fig.5, h), according to the decay of the pulse from the output of the multiplexer 22. At the same time, the pulse from the output of the third one-shot 5 resets the RS-trigger 2 (Fig. 5, c) and enters the counting input of the counter 21 binary, the code at the output of the counter 21 increases by e Init, and applied to the multiplexer block 17 and 15 or. The voltage corresponding to the light source, for which the fusion of two light pulses into one is subjectively felt, from the output of the analog storage device 20 by the first key 8 is switched to the input of the third key 10.

When the next pulse arrives from the output of the second one-shot 4, the RS-flip-flop 2 is set to one, the third switch 10 switches the voltage from the input to the second divider 13, from the outputs of which ten constant voltages through the multiplexers of the analog block 17 are supplied to the inputs of the multiplexer 19 and ten converters, respectively the pulse duration of the block 18. At the output of the first converter, a pulse duration corresponding to the pause of the LED defined at the first stage as the LED iodine, for which he subjectively feels the merging of two light pulses into one. At the output of each subsequent converter, a pulse duration is formed, reduced in comparison with the duration at the output of the previous converter by 0.5 ms. The rest of the circuit works in the same way as described above.

At the second stage, the test subject determines the light source of block 25, for which he subjectively feels the merging of two light pulses into one, and closes the corresponding key of block 30, the output signal of which goes to the encoder 31 and the OR element 16. The rest of the circuit works in the same way as described above.

In this case, the pulse duration corresponding to the light source, for which, at the second stage, the merging of two light pulses is subjectively felt into one, is fed to element 26 through the multiplexer 22 I. When the signal of the logic unit is at the output of the multiplexer 22, the frequency from the output of the generator 28 goes to the counting input of the counter 27, the counting result is displayed on the indicators of the display unit 29. The voltage corresponding to the light source, for which, at the second stage, the merging of two light pulses is subjectively felt into one, from the output of the multiplexer of block 17 through the multiplexer 19 is fed to the analog memory device 20, which is recorded by the pulse from the third one-shot 5, which is triggered by the decay of the pulse from the output multiplexer 22. At the same time, the pulse from the output of the third one-shot 5 resets the RS-flip-flop 2 and enters the counting input of the binary counter 21, the code at the output of the counter 21 increases by one, flushes to block multiplexers 17 and 15 or. The voltage corresponding to the light source, for which at the second stage the merging of two light pulses into one is subjectively felt, from the output of the analog storage device 20 with the first key 8 is switched to the input of the fourth key 11.

When the next pulse arrives from the output of the second one-shot 4, the RS-flip-flop 2 is set to one, the fourth switch 11 switches the voltage from the input to the third divider 14, from the outputs of which ten constant voltages through the multiplexers of the analog block 17 are supplied to the inputs of the multiplexer 19 and ten converters, respectively the pulse duration of the block 18. At the output of the first converter, a pulse duration corresponding to the pause of the LED defined at the second stage by the subjects as a diode for which it subjectively feels the merging of two light pulses into one. At the output of each subsequent converter, a pulse duration is formed, reduced in comparison with the duration at the output of the previous converter by 0.1 ms.

At the third stage, the test subject determines the light source of block 25, for which he subjectively feels the merging of two light pulses into one, and closes the corresponding key of block 30, the output signal of which goes to the encoder 31 and the OR element 16. The rest of the circuit works in the same way as described above.

After reading the values from the indicators of the pause duration indication unit 29, taken as an estimate of the inertia time of the human visual system, the person tested by short-circuiting the key of the unit 30 sets the device to its original state (circuits not shown).

Upon presentation to the subject of two light pulses separated by a pause

t _p > t _cr (Fig. 4, a), he has a feeling of separation of two light pulses (Fig. 4, b). When reducing the duration of the pause t _p between two light pulses to a value of t _p = t _cr (Fig. 4c), there is a subjective sensation of merging two light pulses into one (Fig. 4d). The maximum duration of a pause t _p = t _cr between two light pulses, at which a subjective sensation of fusion of two light pulses into one is achieved, is determined by the inertia parameters of the human visual system (pigv, g):

t _cr = τ ₂ -τ ₁ .

The following values of the inertia parameters of the human visual system are known:

- recovery time τ ₂ [6, 7] or time to maintain visual impression - about 50 ms [11];

- sensation time τ ₁ [6, 7] or critical duration of vision - about 1.5 ms

[12].

Since τ ₂ >> τ ₁ , then for the inertia of the human visual system, the recovery time τ ₂ can be taken:

τ ₂ ≅t _cr .

When the pulse duration is 40–50 ms, the excitation and inhibitory processes by the time the pulse ends are mainly formed [13], therefore, the pulse duration is taken to be 50 ms.

It was experimentally established that the recovery time of the human visual system is in the range from 12 to 31 ms [14], therefore, the pause duration between two light pulses at the first measurement stage is taken for the first LED of block 25 to be 50 ms. The step of increasing the pause duration between two light pulses for the subsequent diode as compared with the pause length of the previous diode at the third measurement stage is 0.1 ms, since the accuracy of counting the time of excitation of the visual analyzer is taken to be 0.1 ms [14].

With a pause duration of 500 ms, the effects of reverse masking, consisting in the deterioration of the perception of the first time pulse due to the presentation of the second pulse in the immediate spatial and temporal proximity with the first, as well as direct masking, in which the first pulse affects the quality of the second, are absent weakly expressed [15]. To eliminate the masking effect, the sequences of two light pulses are repeated at a constant time interval of 1 s.

Thus, the inventive device allows to reduce the research time, so it can be used for mass examinations or during testing by bicycle ergometry in order to assess the degree of fatigue of a person or his functional condition.

Information sources

1. Luizov A.V. Eye and light. - L .: Energy, 1983. - 140 p.

2. Meshcheryakov V.A., Shabaev V.V., Casanovskaya I.A. The technique of automatic tachistoscopy with feedback. // Human physiology. - 1977. - T.3. - Number 3. - S. 549-552.

3. Ivanitsky A.M. Brain potentials in mental operations of varying degrees of complexity. // Human physiology. - 1989.- T.15. - Number 3. - S.11-18.

4. Sagittarius VB Violation of the physiological mechanisms of perception, emotions and thinking in some types of mental pathology. // Human physiology. - 1989.- T.15. - Number 3. - S.135-144.

5. Patent 2220656, A61B 5/16. A device for studying the parameters of inertia of the human visual system. / V.V. Rozhentsov, I.V. Petukhov (RF). - Publ. 01/10/04, Bull. No. 1.

6. Kravkov S.V. Eye and his work. Psychophysiology of vision, lighting hygiene. - 4th ed., Revised. and add. - M. - L .: Publishing House of the Academy of Sciences of the USSR, 1950 .-- 531 p.

7. Semenovskaya E.N. Electrophysiological studies in ophthalmology. - M .: Medgiz, 1963 .-- 279 p.

8. The calculation of the elements of digital devices: Textbook. allowance. / L.N. Presnukhin, N.V. Vorobiev, A.A. Shishkevich; Ed. L.N. Presnukhina. - 2nd ed., Revised. and add. - M.: Higher School, 1991 .-- 526 p.

9. Lantsov A.L., 3vorykin L.N., Osipov I.F. Digital devices on complementary MIS integrated circuits. - M.: Radio and Communications, 1983 .-- 272 p.

10. Analog integrated circuits. Elements, circuits, systems and applications. / Ed. J. Connelly. - M .: Mir, 1977 .-- 440 p.

11. Somov E.E. Ophthalmoergonomics methods. - L .: Nauka, 1989 .-- 157 p.

12. Shamshinova A.M., Volkov V.V. Functional research methods in ophthalmology. - M .: Medicine, 1999 .-- 416 p.

13. Podvigin N.F., Makarov F.N., Shelepin Yu.E. Elements of the structural and functional organization of the visual-oculomotor system. - L .: Nauka, 1986 .-- 252 p.

14. Rozhentsov V.V. Estimation of the recovery time of the visual analyzer using a hardware-software complex. // High technology. - 2004. - T.5. - No. 10. - S.25-29.

15. Taroyan N.A., Myamlin V.V., Genkina O.A. Interhemispheric functional relations in the process of solving a visual-spatial problem by a person. // Human physiology. - 1992. - T.18. - No. 2. - S. 5-14.

Claims (1)

A device for studying the inertia parameters of the human visual system, containing a second pulse generator, a millisecond pulse generator, a first-third one-vibrator, an AND element, an OR element, a counter and an indication unit, the first input of an AND element connected to the output of a millisecond pulse generator, the output to the first input counter, the output of which is connected to the input of the display unit, the output of the second pulse generator is connected to the input of the first one-shot, the output of which is connected to the input of the second one-shot and W counter input, characterized in that an RS-flip-flop, a fourth one-shot, a block of 10 one-shots, a first-fourth analog keys, a first and third resistive dividers, a second OR element, a block of 10 analog multiplexers, a block of 10 converters are added to it voltage-pulse duration, analog multiplexer, analog storage device, binary counter, multiplexer, register, block of 10 OR elements, block of 10 light sources, block of 10 keys and an encoder, the output of the second one-shot connected to the S-input of the RS-flip-flop, the R-input of which is connected to the output of the third one-shot, and the output is connected to the first inputs of a block of 10 voltage-pulse width converters and the second inputs of the second-fourth analog keys, the first inputs of the third-fourth analog keys are connected with the output of the first analog key, the first input of which is connected to the output of the first OR element, the second input is with the output of the analog storage device, the outputs of the second and fourth analog keys are connected respectively to the inputs of the of a third-third resistive divider, the outputs of which are connected respectively by the first or third inputs of a block of 10 analog multiplexers, the outputs of which are connected to the second inputs of a block of 10 voltage-to-pulse converters and the first inputs of an analog multiplexer, the outputs of a block of 10 voltage-pulse converters are connected with the inputs of a block of 10 single vibrators and the first inputs of the multiplexer, the output of which is connected to the input of the third single vibrator and to the second input of the And element, the output of This single-vibrator is also connected to the counting input of the binary counter and to the second input of the analog storage device, the outputs of the binary counter are connected to the fourth inputs of the block of 10 analog multiplexers and to the inputs of the first OR element, the outputs of the block of 10 single vibrators are connected to the second inputs of the block of 10 OR elements the first input of which is connected to the output of the first one-shot, and the outputs are with the inputs of a block of 10 light sources, the outputs of a block of 10 keys are connected to the inputs of the encoder and the second OR element, output The encoder's odes are connected to the first inputs of the register, the output of the second OR element is connected to the input of the fourth one-shot, the output of which is connected to the second input of the register, the outputs of which are connected to the second inputs of the analog and multiplexer, the output of the analog multiplexer is connected to the first input of the analog storage device.

Images