SU733635A1 - Instrument for examining acuity of human vision - Google Patents

Description

one

The invention relates to the field of medical technology and is intended for the study of human vision.

A device is known for examining a person’s visual acuity, comprising a screen with symbols, a keyboard unit, a comparison circuit. Diode array and light panel indicating visual acuity.

In the known device, the speed of investigation is insufficient and possible with: subjective errors introduced by a person into the measurement path.

The aim of the invention is to increase the speed of the study by limiting the exposure time and stopping the research process in case of a patient error.

This goal is achieved by the fact that the fe device has two counters, two decoders, four triggers, five OR circuits and three AND circuits, as well as a time relay. Moreover, the first counter is connected via a decoder to the inputs of three OR circuits, the outputs of which are connected via

a diode array to the control inputs of the comparison circuit, the signal inputs of which are connected via the OR circuit to the first input of the first trigger and the keyboard block output, and the output of the comparison circuit via the second counter and the second decoder is connected to the inputs of three triggers whose outputs are connected to the screen with symbols and to the first inputs of the three circuits And, the outputs of which

10 are connected to a light panel indicating visual acuity. In this case, the second input of the first trigger is connected to the output of the time relay, whose input is connected to the input of the first counter, the first input

15 of the fifth OR circuit and with the output of the comparison circuit, and the output of the first trigger is connected to the second input of the fifth OR circuit, the output of which is connected to the second 2 inputs of the three I.

The drawing shows a block diagram of a device for examining human visual acuity.

37

The device contains counter 1, connected via decoder 2 to the inputs of three circuits 3 - 5 OR, the outputs of which through diode array 6 are connected to control inputs of circuit 7 of comparison, signal inputs of which through circuit 8 OR are connected to the first input of trigger 9 and output block 1O keyboard.

The output of the comparison circuit 7 through the counter 11 and the decoder 12 is connected to the inputs of the flip-flops 13-15, the outputs of which are connected to the screen 16c with symbols and to the first inputs of the circuits 17-19 And whose outputs are connected to the light board 20.

The second input of the trigger 9 is connected to the bypass of the time relay 21, the input of which is connected to the input of the counter 1, the input of the OR circuit 22 and the output of the comparison circuit 7.

The device works as follows.

After power is turned on and all elements are zeroed out (power and zero circuits are not shown in the drawing) from counter 1, signals are sent to decoder 2. From the outputs of the decoder through circuits 3-5 OR one input of the diode matrix 6 is selected, which ensures the formation of a single code output the combination corresponding to the first letter (symbol) of the first line (currently highlighted). The patient presses a key on block 10 of the key corresponding to the first character of the first line of screen 16. If the set is correct, a signal appears at the output of the comparison circuit 7, which changes the state of counter 1 by one and, accordingly, the output of matrix 6 is generated the code corresponding to the second character of the first line of screen 16. This happens until the patient has correctly typed all the characters of the first line. Next, on the second counter 11, a code of the following is generated. the output of the second decoder 12, the signal on which overturns the trigger 13 and sets in I the trigger 14, Thus the first line of the screen with the characters goes out, and the second line (with smaller characters) is displayed.

This process continues until, on one of the rows, the patient makes a mistake, indicating that the resolution limit of his vision has been reached. In the JTOM case b

"

will be formed, although at the output of block 1O of the keyboard, signals are received in the TC that are fed to the inputs of the circuit 8 OR and through the circuit 22 OR the trigger 9 is tilted

5 At the same time, the first inputs of the circuit 17-19 will receive a signal, which is added to the signal at the output of one of the triggers 13, 14 or 15, corresponding to the highlighted line, on which the patient

O recognized the symbol incorrectly, causing the output of one of the 1719 AND signal circuits. This signal will highlight the light display 20 display the results of the study. This scoreboard contains

t5 is the corresponding percentage of the patient's visual acuity. If the error is made on the last line of the screen with 16 characters, the illuminated display with the inscription 10O% lights up.

0 If the patient, considering the character of any line, spends time exceeding the permissible norms, then from the relay output

21 time signal to the circuit

22ILE and then on the light board of the indication of the research results the percentage indicator of vision lights up, as in the case of an error when typing the keyboard for this line.

Thus, the proposed device 30 allows objectively and quickly, without the participation of a physician or other person, to obtain data on the patient's vision.

The proposed device can be used both in medical institutions and in various organizations in dealing with issues of professional suitability or selection.

Claims (1)

Invention Formula A device for examining a person’s visual acuity, comprising a screen with symbols, a keyboard unit, a comparison circuit, a diode array and a visual acuity display light board, characterized in that, in order to increase the speed of the study by limiting the exposure time and stopping the research process in case of a patient error, Two counters, two decoders, four triggers, five OR circuits and three AND circuits, as well as a time relay, are entered into it, the first counter being connected via the decoder to the inputs of three OR circuits, the outputs of which are through the diode array to the control inputs of the comparison circuit, the signal 57 inputs of which are connected via the OR circuit to the first input of the first trigger and the output of the keyboard unit, and the output of the comparison circuit is connected via the second counter and the second decoder to the inputs of three triggers, the outputs of which are connected to the screen with symbols and to the first inputs of the three circuits AND, whose outputs are connected to the light panel indicating the visual acuity, with the atom the second input of the first trigger is connected to the output 35 of the time relay whose input is connected to the input of the first the first inlet of the OR circuit with the output of the comparison circuit, and the output of the first trigger is connected to the second input of the OR circuit, whose output is connected to the second inputs of the three circuits I. Sources of information taken into account during the examination 1. French patent NJ 2215923, class A 61 B C / PA, published. 1975,