SU760945A1 - Method of determining calibrating deflection angles of eyes - Google Patents

Description

The invention relates to medicine, mainly to otolaryngology, and in particular to a method for determining the calibration angular deviations of the eyes.

There is a method of determining the calibration angular deviations of the eyes, providing for the removal and graphic registration of the corneal-mesh potential when observing a moving course with the subsequent selection of the areas corresponding to the calibration angular deviations of the eyes [1]. t

However, the known method only allows for a general form subjectively gauge the angular deviations produce eye selection areas corresponding to them, in view of which is obtained a great accuracy and useful information is lost when ¹ The amount quantitatively estimated calibration.

The aim of the invention is to improve the accuracy of determining the calibration of the angular deviations of the eyes.

This goal is achieved by the fact that 2

in the method of determining the calibration angular deviations of the eyes, providing

removal and graphic registration of the corneal mesh potential while observing

2

moving ply followed by isolation regions corresponding to angular deviations of a calibration eyes simultaneously graphically recorded signal controlling the ply, and the calibration angular deflections determined by eye drop cos ¹ change signs signal Corneal-ply mesh and capacity management based on the time shift between them.

FIG. 1 shows an installation for implementing the method; in fig. 2 - graph of the signal a - controlling the cursor, b - oculogram; in fig. 3 is a graph of the signal a — the controller of the cursor; b — the oculogram, where the calibration angular deviations of the eyes are masked by involuntary eye movements and artifacts.

The method is as follows.

Surveyed 1 in the periorbital area of the eye impose electrodes 2, which remove corneal-mesh potential. Angular deviations of the eyes are caused by observation of the abrupt movement of the light cursor representing two electric lamps 760945

kidneys 3, and components relative to the subject angle o = 20 °. The hopping movement of the light cursor is performed using an electronic device 4 controlling the movement of the cursor with a given frequency. The values of the corneal-mesh potential through the amplifier 5 are recorded as a graph * either on the recorder 6, or fed to the input device of the computer 7. With the help of the same device, which register the corneal-mesh potential, the signal controlling the cursor is simultaneously carried out graphically . If the registration of both signals is carried out using a recorder, then the experimenter visually looks at both graphs, manually determines the coordinates of identical parameters and compares them. This allows you to objectively determine the calibration angle deviations of the eyes. In the case of the registration of the corneal-mesh potential signal and the signal controlling the cursor, the computer further operations comparing the coordinates of identical parameters are implemented by software.

In the process of comparing the coordinates of identical parameters are guided by the following criteria.

The calibration angular deviations of the eyes 25 have the same directions as the corresponding transitions of the cursor, i.e., the corresponding areas of the fast fronts of the graph of the signal controlling the cursor, and the graph of the corneal-net potential coincide with the change of signs. The criterion active ry ³⁰ assumes that the calibration angular deviations are the result of eye observation of the movement runs.

The time shift ψ between the beginning of the cursor and the beginning of the angular deviation of the eyes should be within

O <φ

These time shift limits are determined both by the property of the visual analyzer to program the angular deviation of the eyes before the stimulus begins to move, 40 as well as the delay of the eye reaction due to the inertia of the visual system.

Example 1. The bipolar-silver electrodes are placed in the periorbital regions of the eye and placed in a darkened study cabin. With a frequency of 0.5 Hz, an abrupt movement of the light cursor between two fixation points is performed. The subject monitors the movement of the cursor. As a result of the deviation of the eyes, the resulting changes in the corneal-net potential with the help of electrodes are removed in the form of electrical pulses and fed through an amplifier to one of the recorder inputs, on which they are recorded as a graph. The other input of the same recorder ⁵⁵ simultaneously po- yield and graphically recorded electrical signal pulses of the control runs.

On the graph (see Fig. 2a), the time measured in seconds is plotted on the abscissa axis, the amplitude values of the signal controlling the cursor, in volts, on the graph, the coordinates of the points along the abscissa axis

I, 3, 5 and so on? The corresponding areas of fast fronts are the time of the beginning of the cursor movement, and the coordinates of points 2, 4, 6, etc. of the same fronts along the abscissa axis are the time of the end of the cursor movement. The difference in the coordinates of the points 2 and 1, 4 and 3, '6 and 5, etc., along the ordinate axis determines the changes in the signs of motion of the cursor. A negative sign corresponds to the movement of the light cursor from left to right, and a positive value from right to left, Τι, Ta, Tz, etc. correspond to a half-period. spasmodic motion of the course with a duration of 1 s.

The abscissa axis of the graph (Fig. 26) lays the time measured in seconds, and the ordinate axis the amplitude value of the amplified signal of the corneal-mesh potential, proportional to the angular deviation of the eyes, in volts. Coordinates of points

I ^I , C ¹ , 5 ¹ and so on. The corresponding areas of fast fronts along the abscissa are the time of the beginning of eye movements, and the coordinates of the points are 2 ¹ , 4 ', 6 ¹ , etc. the same fronts on the x-axis - the end time of the deviation of the eyes. The difference of the coordinates of points 2 ¹ and I ¹ , 4 ¹ and 3 ', 6 ¹ and 5 ¹ , etc. the axis of ordinates determines the changes in the signs of the angular deviation of the eyes. A negative sign corresponds to the angular deviation of the eyes from left to right, and a positive sign from right to left, similar to the cursor movement.

On the graph, fast fronts I ¹ –2 ¹ , H ¹ –4 ¹ , 5'– 6 ¹ , etc. they are similar in shape to the fronts of gauge angular deviations of the eyes. To determine which of these areas reflect the true reactions of the eyes in the course of the cursor, that is, correspond to the calibration angular deviations, proceed as follows.

The time coordinates of points 1, 3, 5, etc. of the graph of a (Fig. 2) are transferred to the abscissa axis of the graph b and lay off from them the maximum value of the time shift 1/3 s, which in this case is equal to 1/3 Tc (ϊ = 1, 2, 3 ...). Find those coordinates of the beginning of the areas of fast fronts of the graph b, which are in the intervals φ. For areas of fast fronts that have similar coordinates, changes in the signs of the corresponding areas of fast fronts of the graph and of the cursor's motion signal are determined. As a result, those areas of fast fronts of graph b, which, by changing signs, coincide with the corresponding areas of fast fronts of graph a, are considered as calibration angle deviations of the eyes. Determining in this way the calibration angular deviations of the eyes from the graph b highlight the following areas:

760945

6

p — 2 ^ι , 3 ¹ —4 ^! 7 ^{1 ι} -8, 9 ^'1 -10, 19 ¹ - 20 ¹

21' — 22 ¹ and 23 ^ 24 ¹ . The remaining areas are not selected, as they do not meet the specified criteria.

Example 2. Both graphs (. Figure 3) ₅ cheny obtained in the same manner as in Example 1. Areas graphics 7 b ¹ * -8 17 * -18 ¹ 19 -20 ¹ *, 23 * - ²⁴ January, ZZ ¹ —341, 42 ¹ —43 ', 44 ^ 45 ¹ are allocated as calibration angular deviations of eyes.

Software implementation of the proposed ίο method using a computer in examples 1 and 2 gives the same results as manually.

The proposed method allows an average of 25% increase in the accuracy of determining the calibration angular deviations of the eyes. ¹⁵

Claims (1)

Claim The method of determining the calibration angular deviations of the eyes, providing removal and graphic registration of the corneal-mesh potential when observing a moving cursor with the subsequent selection of areas corresponding to the calibration angular deviations of the eyes, characterized in that, in order to improve accuracy, simultaneously register the signal controlling the cursor, and the calibration angular deviations of the eyes are determined by coincidence changes in the signs of the corneal-mesh potential signals and control of the cursor, taking into account the time shift between them.