SU1762897A2 - Device for measurement of critical glimpses confluence frequencies - Google Patents

Abstract

The use of the invention relates to medical technology and can be used in vocational guidance, in the operational monitoring of human performance, in determining the fatigue of a person during a work shift, as well as for diagnostic purposes. Essence: the device contains the test key 1, shift register 2, first-sixth triggers 3-8, first-fourth waiting multivibrators 9-12, mode switch 13, linear variable voltage generator 14, voltage-frequency converter 15, source 16 light pulses, the first 17 and second 18 OR elements, the average value calculator 19, the indication unit 20, the comparator 21, the fault indicator 22, the first 23 and second 24 counters, the comparison element 35, the one-shot 26, the reset key 27. The device allows determining the ratios of critical frequencies recorded at times T4 and T7 of flicker, thereby checking the correctness of their determination, and increasing the reliability of studies. 2 Il.

Description

FIG. one

The invention relates to medical technology, in particular, devices for assessing the psycho-physiological parameters of a person, and can be used in vocational guidance, in operative monitoring of human performance, in determining human fatigue during a work shift, as well as for diagnostic purposes,

According to the main author. St. USSR No. 1623605, a device for measuring the critical frequency of flicker fusion is known, which contains the test key, shift register, five flip-flops, three multivibrators waiting, mode switch, linear voltage generator, voltage-frequency converter, light source, OR element , a mean value calculator, a display unit, a comparator and a failure indicator, the key output being connected to the input of the shift register, the first output of which is connected to the first input of the first trigger, the second output d - with the second input of the first trigger, the first input of the second trigger and the input of the first waiting multivibrator, the third output - with the second input of the third trigger and the input of the second waiting multivibrator, the fourth output - with the second inputs of the fifth trigger and the OR element, the output of the first waiting multivibrator is connected with the second input of the second trigger and the first input of the third trigger, the output of the second waiting multivibrator is connected to the first inputs of the fourth trigger and the OR element and the input of the third waiting multivibrator, output cat The first is connected to the second input of the fourth trigger and the first input of the fifth trigger, the trigger outputs are connected via a mode switch to the generator input, the output of which is connected to the comparator and converter inputs, the outputs of which are connected respectively to the inputs of the LED indicator and the source of light pulses, the converter output It is also connected to the first input of the average value calculator, the second input of which is connected to the output of the OR element, and the outputs to the inputs of the display unit.

The drawback of the device is the lack of control over the reliability of measurement of the critical flicker frequency. If the critical frequency of flickering is incorrectly determined, the frequency F recorded by the subject at time T4 is equal to or even less than the frequency F recorded by the subject at time T7.

With the correct determination of the critical frequency of flickering due to the presence of the reaction time, the frequency F1 is always greater than the frequency F.

The purpose of the invention is to increase the reliability of research results by monitoring the accuracy of determining the critical frequency of flicker.

FIG. 1 shows a functional diagram of the device; in fig. 2 - time diagram of his work.

The device contains the test key 1, the shift register 2, the first - the sixth trigger 3-8, the first - the fourth

pending multivibrators 9-12, a switch of 13 modes, a generator of 14 linearly varying voltage, a voltage-frequency converter 15, a source of 16 light pulses, the first and

the second element OR 17-18, the average value calculator 19, the display unit 20, the comparator 21, the fault indicator 22, the first and second counters 23-24, the comparison element 25, the one-shot 26 and the reset key 27.

Triggers 3-7 are standard R-S triggers, trigger 8 is a synchronous D-trigger with a preset zero input. At the same time, only one of the triggers can be in the on state.

As a generator of linearly varying voltage, a standard integrator on an operational amplifier with input registers switched by switch 13 is used to obtain a different voltage rise rate at the output of generator 14, and to change the polarity of the input voltage. integration direction (rise or fall of output voltage).

The calculator 19 determines the average of two values of the frequencies of light flashes recorded by the subject.

The comparator 21 generates a signal / when decreasing or exceeding the input voltage, relative to the values corresponding to the minimum and maximum

critical frequencies of flicker equal to, respectively, 20 and 50 Hz.

Counters 23 and 24 determine the frequency of flicker fusion recorded by the subject at times T4 and T7. Comparison element 25 determines the ratio of these frequencies. With proper determination of the critical frequency of the fusion; the flicker frequency recorded by the subject at time T4 should be

more than the frequency recorded at time T7.

The single-oscillator 26 produces a pulse, the duration of which is longer than the time interval T4 - T5 or equal to it T7 - T8 for the duration of the transients of the comparison element 25.

The device works as follows. In the initial state, the triggers 3-8 are turned off, the counters 23 and 24 are cleared, the code 2,000 is written to the register 2, the generator 14 outputs a constant voltage to the converter 15, which corresponds to the initial frequency F1 of light flashes. Transducer 15 converts this voltage to a frequency that controls source 16 (time interval 0 - T1).

The subject presses key 1 (time T1). The pulse from key 1 shifts the state of register 2 by one bit to the right, the signal from the first output of register 2 turns on trigger 3, which through switch 13 sets generator 14 to the generation mode of a rapidly changing ramp voltage with S1. Converter 15 converts this voltage to a proportional variable frequency, which source 16 transforms i into light pulses delivered to the subject (time interval T1 - T2). At the moment of light flashing, the subject presses key 1 (time T2, frequency F2), the pulse from which again shifts the state of register 2 by one bit to the right. The signal from the second output of the register 2 turns off the trigger 3, starts the multivibrator 9 and turns on the trigger 4, the latter through the switch 13 sets the generator 14 into the generation mode of a fast-moving linearly falling voltage with slope S2. The time interval T2 - TZ is determined by the duration of the pulse produced by the multivibrator 9, and the frequency is reduced by a fixed amount equal, for example, to 5 Hz. At the moment of time TZ, the multivibrator 9 is turned off and the back edge of the pulse turns off the trigger 4 and turns on the trigger 5, which through the switch 13 sets the generator 14 to the generation mode of a slow-moving linearly increasing voltage with a slope S3, transformed along the circuit generator 14-converter 15 - source 16 to light pulses (time interval TZ - T4). At the time of light flashing (time T4, frequency F), the subject presses key 1, the state of register 2 is again shifted by one bit to the right,

the signal from its third output turns off the trigger 5 and turns on the multivibrator 10. The generator 14 maintains a constant voltage at the output corresponding to the frequency F. From the output of the multivibrator 10, a pulse through the element 17 OR is fed to the calculator 19, in which the value of the frequency F is recorded. In addition, the pulse from the output of the multivibrator 10 is fed to the first counter 23 and allows it to work. The frequency F is read by the counter 23 during the time interval T4-T5, which is determined by the duration of the pulse produced by the multivibrator 10. At time T5, the multivibrator 10 is turned off and the trailing edge turns on the multivibrator 11 and the trigger 6, the latter through switch 13 sets the generator 14 to generating a rapidly increasing ramp voltage with a slope S2, and the frequency increases by 5 Hz. The time interval T5 - T6 is determined by the duration of the pulse generated by the multivibrator 11. At time T6, the multivibrator 11 is turned off and the back edge of the pulse turns off the trigger 6 and turns on the trigger 7, the latter through the switch 13 sets the generator 14 into a mode of generation of a slowly varying falling voltage the S3 slope, which is transformed along a circuit; the 14-converter generator 15 - the source 16 to light pulses (time interval T6 - T7). At the time of the flickering of light (mo11

Time T7, frequency F) the subject presses key 1, the state of register 2 is shifted by one bit to the right, the signal from its fourth output turns off the trigger 7, the generator 14 maintains a constant voltage at the output corresponding to the frequency F. At the same time, the signal from the fourth output of register 2 through element 17 OR goes to the calculator 19, into which the value of frequency F is written. In addition, the signal from the fourth output of register 2 starts the multivibrator 12, from which the pulse goes to the one-shot 26 and the second counter 24, operation the latter is permitted. The frequency F is read by the counter 24 during the time interval T7 - T8, which is determined by the duration of the pulse produced by the multivibrator 12. The time interval T7 - T8 is equal in duration to the time interval T4 - T5. In the calculator 19, the average value of the frequencies F and F is determined, the result is output to the display unit 20. Comparison element 25 compares the values of the frequencies F1 and F and, when the signal is

the output of the comparison element 25 is fed to the D input of the trigger 8, which is triggered by the falling edge of the pulse from the one-shot 26 fed to its C input. If the critical flicker frequency at flashes T4, T7 is incorrectly determined, then the frequency F is equal to or less than the FIL frequency. In this case, the comparison element 25 does not produce a signal, the signal from the inverse output of the trigger 8 passes through the second 18 OR element and turns on the indicator 22. Upon completion of the processes, calculator 19 generates a pulse that sets the device to its initial state (circuits not shown), with the exception of trigger 8, which is reset to the initial state by pressing the reset key 27.

In the event that the subject misses the moment of flicker on the intervals T1 - T2, TK - T4 or T6 -17, further testing does not make sense, and the comparator 21 set to the minimum and maximum values of the critical flicker of the person, through The second element 18 IL-I turns on the indicator 22, and returns the device to the initial state (circuits not shown).

Thus, the device allows to ensure the reliability of research results by checking the correctness

determining the critical frequency of flicker.

Claims (1)

The invention of the device for measuring the critical Frequencies of flashing on aut. St. No. 1623605, characterized in that, in order to increase the reliability of research results by checking the correctness of the determination of the critical frequency If there are flashes, two counters, a comparison element, a fourth multivibrator in wait, a single vibrator, the sixth trigger, the second OR element, and a reset key are added to it, and the counting inputs the meters are connected to the output of the voltage converter — the frequency; the enable input of the first meter — to the output of the second standby multivibrator; the meter outputs — to the inputs of the reference element, the output of which is connected to the D-input of the sixth trigger, the input of the fourth standby multivibrator is connected to the fourth output of the shift register, the output to the permission input of the second counter and the input of the one-vibrator whose output is connected to the C-input of the sixth trigger, the zero input of the sixth trigger is connected to the output reset key, inverse output - with the second input of the second element OR, the first input of which is connected to the comparator output, and the output - to the input of the fault indicator. I 77 n pz 77 Editor 7 T5T6 FIG. 2 Compiled by V. Rozhentsov Tehred M.MorgentalKorrektor I. Shulla S3 77 78