RU2066971C1 - Device for monitoring pupillary reflex - Google Patents

Abstract

FIELD: medical equipment, in particular, neuroophthalmologic apparatuses used for examination of reaction of the pupil of the eye. SUBSTANCE: device for monitoring of pupillary reflex comprises an illuminant unit, viewfinder unit and a projection unit optically and mechanically connected to each other; light stimulation unit optically tied-in with the projection unit optical axis, electronic unit electrically coupled to the light stimulation unit, illuminant unit, projection unit photodetector and electrooptical transducer of the viewfinder unit; the illuminant unit is made as a set of infrared light-emitting diodes positioned on an annular holder rigidly connected to the projective unit lens and optically tied-in with the patient's eye; the light stimulation represents a light-emitting diode operating both background lighting diode and in the impulse light flash mode positioned in the unit optical axis is a plate with a fixing point made on intersection of the optical axis of the projection unit, light stimulation unit and patient's optic axis. The device prevents any influence of thermal effect on the eye surface and influence of light flux fluctuation on the pupil. EFFECT: enhanced accuracy and truth of examination results. 1 dwg

Description

 The invention relates to the field of medical technology, namely to neuroophthalmic devices used to study the reaction of the pupil of the eye. It can be used in medical practice in neuro-ophthalmologic, ophthalmologic, neurological rooms, during mass prophylactic examinations, in automated systems of mass prophylactic examination during medical examination of the population.

 Conducted patent information research found that a device for registering the pupillary reflex is known. Thus, devices are known for recording the pupil reflex, the main ones based on the film projection principle (2-1) and the photoelectronic principle (2-4).

 The prototype of the claimed technical solution is a photoelectronic pupillograph (V.F. Ananin. Reflexology. M. Publishing House of the Peoples' Friendship University of Russia, Biomedinform, 1992, pp. 144-145). This device comprises a light stimulation unit, a viewfinder unit, a projection unit with a photodetector, an illuminator unit, an electronic unit. The disadvantage of this device is that the illuminator unit, made in the form of an infrared illuminator containing an incandescent lamp, a condenser and an infrared filter, creates a thermal effect on the surface of the eye and thereby introduces physiological discomfort during the registration of the pupil reflex.

 In addition, the use of an incandescent lamp is associated with the use of a complex highly stabilized electronic source of its power.

 The stimulation unit, made in the form of an LED, a fiber optic bundle, a flash lamp, a mirror, on the one hand, introduces a screening of the pupil image on the photodetector by installing a mirror on the optical axis of the projection channel; and, on the other hand, the reflected flow from the translucent plate introduces a short-term exposure to the photodetector, thereby reducing the durability of its work.

 The essence of the invention lies in the fact that in the device for recording the pupil reflex, containing the illuminator unit, the viewfinder unit and the projection unit, optically and mechanically interconnected, the light stimulation unit optically coupled to the optical axis of the projection unit, the electronic unit is electrically connected to the unit light stimulation, the illuminator unit, the photodetector of the projection unit and the electron-optical converter of the viewfinder unit, the illuminator unit is made in the form of a set of infrared light of the diodes placed on an annular frame rigidly connected to the lens of the projection unit and optically conjugated with the subject’s eye, and the light stimulation unit is an LED operating both in the background illumination mode and in the pulsed light flash mode, in the optical axis of which there is a plate with a fixation point made at the intersection of the optical axis of the projection block, the light stimulation block and the visual axis of the subject.

 The proposed device for recording the pupil reflex eliminates the thermal effect on the surface of the eye and thereby eliminates side factors affecting the registration process of the pupil reflex and thereby increases the accuracy and reliability of the examination results.

 Elimination of the complex part of the circuit of the electronic unit responsible for the power supply of the incandescent lamp of the illuminator unit made it possible to drastically reduce the influence of both the pulsation of the electric power supply of the lamp and the instability of the light flux of the lamp itself on the results of recording the pupil reaction.

 Elimination of the screening mirror on the light path of the projection unit avoids any distortion in the image of the test pupil. The device allows to determine in absolute values the time parameters of the pupillogram: latent period of narrowing, time of narrowing, latent period of expansion, expansion time, total reaction time of the pupil with high accuracy up to 20 and less than milliseconds.

 Figure 1 shows a device that includes an illuminator unit, consisting of infrared LEDs 1, optically coupled to the pupil of the eye of the subject and the optical axis of the projection unit, the landing ring 2, rigidly connected to the lens of the projection unit; a projection unit including a lens 3, a glass plate 4, a spherical lens 5, a photodetector 6, optically paired with each other; the viewfinder unit, which consists of a lens 7, a mirror 8, and an electron-optical converter 9. The illuminator unit, the projection unit, and the viewfinder unit are optically and mechanically interconnected. The device also contains a light stimulation unit, consisting of an LED 10, a translucent plate 11, optically coupled to the optical axis of the projection unit. The electronic unit includes an amplifier 12, an interface board 13, a power supply 14, and is electrically connected to the stimulator unit of the illuminator and to the photodetector. Figure 1 also shows the eye of the operator 15, the eye of the subject 16 and the personal computer 17.

 A device for registering a pupil reflex works as follows.

 A person tested by his eye 16 fixes a fixation point located in the center of the plate 4 through the light stimulation unit, lens 3 of the projection unit, which is illuminated by weak background illumination from the LED 10 operating in the low current mode, thus holding his eye in a relatively stationary position.

 At the same time, the surface of the eye of the subject 16 is illuminated by the invisible infrared light of the illuminator unit in the form of a light spot equal in size or larger than the size of the iris.

 The image of the pupil and the iris using the lens 3 of the projection unit, the spherical lens 5 is projected into the plane of the sensitive layer of the photodetector in such a way that it fully fits on it (fig.1b). In addition, part of the light flux reflected from the glass plate 4 enters the viewfinder unit. In it, through the lens 7, mirror 8, the light flux is directed to the electron-optical converter 9, in which the invisible image of the pupil and iris is converted into visible. The operator 15 sets the image of the pupil in the center of the crosshairs (figa). With this setting of the pupil image in the viewfinder's field of view: the image of the pupil and iris on the sensitive layer of the photodetector is also set in its center (Fig. 1b). After the above adjustment is carried out, the operator, by turning on the light diode 10 in the pulse current mode, delivers a light flash through the translucent plate 11, the glass plate 4 mounted in the focus of the lens 3. The latter, passing through the lens 3, enters the eye 16 in the form of a parallel beam centered along the visual axis of the subject's eye.

 Since the illumination of the subject’s eye and its aiming is carried out using the infrared illuminator unit, recording of its pupillary reflex can be carried out both in complete darkness and at other values of background illumination. At the moment a light flash enters the subject’s eye, the pupil becomes narrowed through the latent period of the pupil reaction. As a result, a redistribution of the light flux occurs on the sensitive layer of the photodetector and, as a result of this, the appearance of an electrical signal of an analog form in the form of a pupillogram. The latter is amplified by an amplifier 12 and through the interface board 13 it enters a personal computer 17, where it is processed according to a special program, and the processing results are printed on a computer.

 The power supply 14 at the time of turning on the device to work synchronously turns on the electrical power of the photodetector 6, LED 10, amplifier 12 and the power of the electron-optical converter.

INFORMATION SOURCES
1. Shakhnovich A.R. Shakhnovich V.R. Pupillography. M. Medicine, 1964.

 2. Binopular device for recording micro-movements of the eyes and pupillary reflexes. Ananin V.F. Sokolina E.S. In the collection News of medical instrument engineering (proceedings of VNIIMP), vol. 2, 1967, p. 54-59.

 3. Ananin V.F. Reflexology. M. Publishing house "RUDN", p. 144-147.

 4. Ananin V.F. The theoretical basis of iridology. M. Publishing house "LETMO", t. 1, p. 17-24.

Claims (1)

 A device for recording a pupil reflex, comprising a illuminator unit, a viewfinder unit and a projection unit, optically and mechanically interconnected, a light stimulation unit optically coupled to the optical axis of the projection unit, an electronic unit electrically coupled to the light stimulation unit, an illuminator unit, a projection photodetector the unit and the electron-optical converter of the viewfinder unit, characterized in that the illuminator unit is made in the form of a set of infrared LEDs placed on an annular frame rigidly connected to the lens of the projection unit and optically conjugated with the subject’s eye, and the light stimulation unit is an LED operating both in the background lighting mode and in the pulsed light flash mode, in the optical axis of which there is a plate with a fixation point made at the intersection in the optical axis of the projection block, the light stimulation block and the visual axis of the subject.