SU740225A1 - Apparatus for measuring eye motion - Google Patents

Description

one

The invention relates to the field of medical technology, namely to devices for measuring eye movement, and is intended for psychological and neurophysiological experiments.

A device for measuring eye movement is known, comprising a short-circuited coil attached to a contact lens, a central coil mounted parallel to the frontal plane of the spectacle frame, and four coordinate coils, as well as a high-frequency generator 1.

However, the known device does not allow to display the vector of the deviation of the eye in the polar coordinate system.

The chain of the present invention is the display of eye movements in the polar coordinate system.

This goal is achieved by the fact that the device has a square phase phase-shifting circuit, an amplitude detector, two amplifier limiters, a symmetric trigger, and two filters, the high-frequency generator connected directly to one pair of counter-coherent coordinate coils and

goy - through quadrature phase shift-. a damming circuit, the input of one limiter amplifier is connected to the output of the high-frequency generator, the input of the other amplifier limiter is connected to the central coil, the outputs of both of the limiter amplifiers are connected to the inputs of a balanced trigger whose output is connected to one

0 by the filter, the input of the amplitude detector is connected to the central coil, and its input is connected to another filter.

The drawing shows a block diagram

15 dp device measuring eye movements.

The device contains a high-frequency generator 1 connected to counter-connected co-ordinate co-ordinate coils 2, 3 directly, and to coils 4, 5 through a quadrature phase-shifting circuit, 6, two amplifier-limiter 7, 8, and the input of amplifier-limiter

25 7 is connected to the output of the generator 1, and the input of the amplifier-limiter 8 is connected to the central coil 9. The outputs of both limit suppressors are connected to the inputs of the symmetric trigger 10, whose output is connected to the filter 11, and the input of the detector is 1-2 connected to the central coil 9, its output connected to the filter 13. The device also contains a short-circuited coil 14 attached to a contact lens.

The device works as follows.

With a deviated eye with a squirrel-cage coil 14 from the center position, the excitation currents of the same counter-current: Consecutively connected coordinate coils 2, 3 and 4.5

i (t) asinu; t, i / t} .acosujt,,

where 3 is the amplitude;

UJ - circular frequency ,,

through mutual inductances with a co-closed coil 14

xSe,% 9x

and M (.ej,

where is M.

- initial mutual inductances of horizontal and vertical coordinate coils (with 0). 6 Q - deviation of visual

- the axes of the eye with a short-closed coil with respect to the vertical and horizontal planes, form the flux couplings v e Hj sinu / t, 9,, Mp3cosa i, which are pro-1: 1 short-circuited coil. i, emf induced in it e, -dt (+%), This emf in a short-circuited coil sucks the secondary exciting current

i (t). e -1ёi g shEcosM g,

where l§UVe i6

the module of the deviation of the spectator's eye;

E-arctg - the phase of the vector from the J-declination of the visual axis of the eye,

The secondary exciting current i, through the mutual inductance M Srcongi between the short-circuited coil 14 and the central coil 9, forms a flux linkage from the leading emf in the central coil,

dH, (, t) lel55m (),

where is the sensitivity of the meter, / From this it is seen that the amplitude of the EMF of the central coil is proportional to the modulus in which the deviation of the visual axis} in | and its initial phase is the phase of deviation of the vector of the visual axis,

Voltage proportional to amplitude is extracted from EMF 9 by an amplitude detector 12, and after filtering the pulsation by filter 13, the amplitude output is applied.

,: ...., „

The voltage Ug has a periodic rectangular shape with a constant amplitude A and an initial phase B, the voltage C, has the same shape, but the initial phase is constant and equal to zero. These front voltages trigger a symmetric trigger 10. At its exit, pulses are generated, the duration of which is proportional to the measured phase shift:

(fe)

where t

the period of the compared signals,

5, the low-frequency filter 11 allocates a constant pulse voltage component equal to.

ABOUT

u, - Kef-KBj f-S (e),

where K is the filter transfer coefficient; B is the amplitude of the output voltage of the trigger.

Thus, this device allows to display eye movements in a polar coordinate system.

Claims (1)

Invention Formula An apparatus for measuring eye movement comprising a short-circuited sleeve attached to a contact lens, a central coil; an adjustable parallelejb of the frontal plane of the spectacle frames, and four coordinate coils, as well as a high-frequency generator, which are different in that in order to display eye movements in polar coordinate system, it has a quadrature phase-shifting circuit, an amplitude detector, two usi. lit dd, symmetric trigger and two filters, with a high frequency generator connected to one pair of counter-series connected coordinate coils directly, ac another through quadrature phase shift & circuit, the input of one amplifier limiting amplifier connected to the output of a high frequency generator, The input of another limiter amplifier is connected to the central coil, the outputs of both the limiting amplifiers are connected to. symmetric trigger, whose output is soy; ainens is one filter, the input of the amplitude detector is connected to the central coil, and its output is connected to another filter. Sources of information taken into account in examination 1, Mitrani L, Saccadic eye movements and vision, Sophie, Publishing House AN NRB, 1973, p. 31-32. wfe32: jS3: fle :; - tti.