RU9700U1 - DEVICE FOR STUDYING EYE STATE - Google Patents

Abstract

1. A device for studying the state of the eye, containing a pulse generator, the control input of which is connected to the frequency regulator, the output is connected to a rectangular pulse shaper, the output circuit of which is included in the power supply circuit of the light source, a current generator, the control input of which is connected to the current regulator, and the output the circuit is connected to one of the output terminals intended for contact with the patient, characterized in that the output circuit of the square-wave pulse generator is also connected via the introduced trans a galvanic isolation converter unit with an input of an introduced modulator, the output of which is connected via a step-up transformer and rectifier to a second output terminal, and a unit for measuring current and frequency specified by current and frequency controllers. 2. The device according to claim 1, characterized in that the current generator is made on a transistor, the collector of which, forming the output circuit of the current generator, is connected through a diode to the power source of the current and frequency controllers, and the control input is connected to the output of the current regulator.

Description

accuracy of measurements.

The technical result is achieved due to the fact that in the device for examining the state of the eye, containing a pulse generator, the control input of which is connected to the frequency regulator, the output is connected to a rectangular pulse shaper, the output circuit of which is included in the power supply circuit of the light source, the current generator, the control input of which connected to the current regulator, and the output circuit is connected to one of the output terminals intended for contact with the patient (2),

the output circuit of the square-wave pulse generator is also connected through the input galvanic isolation unit to the input of the introduced modulator, the output of which is connected via a step-up transformer and rectifier to the second output terminal, the current and frequency measurement unit, which are set by the current generator and frequency generator.

In addition, the current generator can be performed on a transistor, the collector of which, forming the output circuit of the current generator, is connected through a diode to a power source, and the control input is connected to the output of the frequency controller. This device provides galvanic isolation of powerful power circuits from the output measuring circuits connected to the patient, which led to the exclusion of a mode of short circuit in the load that is dangerous for him, without the need for additional protective circuits that complicate the device. Due to the introduction of additional mixing into the collector circuit of the transistor of the current generator, the measurement accuracy is increased with the expansion of the frequency range.

The drawing shows an electrical diagram of the device.

The device comprises a pulse generator 1, made in the form of a DC-to-frequency converter with a frequency divider. The control input of the frequency generator 1 is connected to a frequency controller 2, which can be performed according to the transistor current generator circuit, in which the frequency is controlled using variable resistors. The output of the pulse generator 1 is connected to a rectangular pulse shaper 3, the output circuit of which can be made in the form of a stabilizer on a transistor, included in the power supply circuit of a light source made on the LED 4.

The output circuit of the rectangular pulse shaper 3 is also connected via a transformer galvanic isolation unit 5 to the input of the modulator 6, the output circuit of which includes a step-up transformer 7 connected

to Rectifier 8. A current generator 9, made on transistor 10, by controlling Input is connected to current regulator 11. The output circuit of current generator 9, formed by the collector of transistor 10, is connected through diode 12 to a power source of current and frequency controllers 11 and 2, made according to the scheme transistor current generators, the output parameters of which are adjusted using variable resistors. The current and frequency are measured by the current and frequency measuring unit 12, which may be a voltmeter calibrated on an appropriate scale of current and frequency.

The device has three operating modes:

1) sensitivity determination mode,

2) lability determination mode,

3) the mode for determining the critical frequency of flicker fusion.

In the first mode, the minimum current value is determined at which the patient

will feel the appearance of phosphene. For this, the electrodes connected to the output

findings are brought to the patient. Frequency controller 2 is set to low

frequency. The current regulator 11 changes the current in the output circuit of the current generator 9, a,

therefore, in the chain of output terminals until the appearance of phosphene. Value

the detected current value is fixed by the current measurement unit and often 12.

In the mode of determining lability (pulse mode of operation of the device)

determines the frequency at which the patient still feels phosphene. For this

the current regulator 11 sets the current in the output circuit, at which

phosphene would be of sufficient brightness, then the frequency control 2 increases

frequency in the chain of output terminals until the fusion of phosphene into a continuous background.

The current and frequency measurement unit 12 fixes the detected frequency.

In the measurement mode of the critical fusion flicker frequency, an analysis is performed.

transition time of the visual analyzer from a neutral state to

excited. A light source (LED emitting

red light signal), the frequency controller 2 sets the frequency,

in which the patient sees a constant background instead of intermittent light. Knot

current and frequency measurements 12 this frequency is fixed

Thus, using this device, you can diagnose the condition

human eyes with maximum accuracy while ensuring electrical safety

measuring

Compiled by V.A. LikhachevlЈ id

Sources of information taken into account when drawing up the description: RU 936882 A 61 B 3 / 12.1980.

Claims (2)

1. A device for studying the state of the eye, containing a pulse generator, the control input of which is connected to the frequency regulator, the output is connected to a rectangular pulse shaper, the output circuit of which is included in the power supply circuit of the light source, a current generator, the control input of which is connected to the current regulator, and the output the circuit is connected to one of the output terminals intended for contact with the patient, characterized in that the output circuit of the square-wave pulse generator is also connected via the introduced trans a galvanic isolation converter unit with an input of an introduced modulator, the output of which is connected via a step-up transformer and rectifier to a second output terminal, a unit for measuring current and frequency, set by current and frequency controllers. 2. The device according to claim 1, characterized in that the current generator is made on a transistor, the collector of which, forming the output circuit of the current generator, is connected through a diode to the power source of the current and frequency controllers, and the control input is connected to the output of the current regulator.