JPS59120127A - Apparatus for examining and calculating visual field - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The claimed invention relates to a device for visual field testing and calculation, which device has fundamentally novel features and many features compared to known devices used for similar purposes. has advantages.

The @ position (i.e., planar perimeter) of the present invention was designed and constructed in an entirely original manner, based on preliminary clinical research using clinical techniques of medical science and microprocessors.

The bones of the invention encompass medical fields involving the visual system, such as ophthalmology, neuroscience, and neurophysiology. Its use is in neurobiological examination for diagnostic purposes and experimental clinical intervention for scientific purposes.

The originality of the device according to the invention resides in both its physical construction and its functional concept, which are unmatched by any device of similar characteristics as described below.

The basic principle consists in using a wide-angle cathode ray tube (ORT), such as an perimetry (OampOmetrio) screen, so as to provide a background and luminous stimulation points that can stimulate an active response in the subject to be examined. Occur.

The basic equipment for generating and amplifying the video signal must be kept in mind in terms of features such as variable brightness decay spread over the screen surface, test stimulation points of variable brightness and variable position, and the type of examination to be performed. It also allows the existence of points. This is achieved by energizing the CRT cathode by 3N with a power amplifier specifically designed for this purpose.

The background and test stimulus points cover uniquely discrete values in a linear ratio of 10000:1 from the maximum flux to the small flux in order to achieve a scale of resolution sufficiently large for practical visual field examination.

One of the advantages derived from the use of CRTs, such as the perimetry screen and video electronics of the present invention, is the large angular resolution of 0.2 square degrees or more.CR
A similar inventive method for setting fixation points at different locations of the T's diagnostic range expands the diagnostic field for the viewing range.

The expansion of this field is 30 degrees from the screen to the insect eye.
For a 20-inch diagonal tube, the angle is 60' horizontally and 48° vertically.

For the above-mentioned visual acuity, four fixation points occur in sequence at the corners of the screen. The subsequent configuration of the examined quadrants is done automatically by programming.

Finally, the application of the luminance stimulation point generator and one or more cathode ray tubes is accomplished in an inventive manner by a combination of reasoning techniques as described below.

(1) Perimetry technology (2) Acumetry technology (
3) Gaze-linked technique (4) Fusion critical frequency technique The achromatic and chromatic absolute subvalues of retinal sensitivity and their anatomical distribution are determined by perimetry techniques. For this purpose, stimulation points appear on a zero-luminance background from zero level until they are perceived by the patient. The parameters used are as follows.

Luminance of one ambiguity: zero value. Luminance of one test stimulus point: value programmed discretely in increasing amounts of IE from zero until perceived.

The shape and dimensions of one test stimulation point are variable depending on the Nibrogram.

The color of one test stimulus point can be selected by the Nibrogram.

-Point of fixation.

(a1 number: different values from 1 to 5 as a function of the retinal area to be examined; visual field center position 4° for investigation of the blind spot area; bl brightness: unchanged during the examination;

The perimetry technique, which also allows the determination of achromatic or chromatic differences, is a test on the dorsal luminance, where the stimulus point luminance is varied until the luminance is determined in contrast with the dorsal lumen. For a given level of brightness, the brightness increase of the test stimulus point should be either l'E or negative.

Until now, only one threshold for the increase of [E has been set. 17 However, as in the present invention CR
When using T, a negative increase in the trial olfactory stimulation point will result in the establishment of a new parent measurement technique to measure different thresholds. The parameters used here are as follows.

Background brightness: Adjustable by program between 00 and 1000 brightness.

-Going point: Same as above.

One prick (scattering brightness nibogram starts from the background brightness value and is variable at positive or negative discrete intervals.

Size of one stimulus point: Variable by program from a minimum of 0.2 square degrees.

Can be selected by color nibrogram of one stimulus point.

The device according to the present invention can be used to examine the visual field in an appropriate amount of time and to examine the visual field. The determination of the 1q value is automatically carried out.

Depending on the selection, changes in the position of the gaze point and the area of the visual field to be examined are selected. That is, they choose the center field at the center of the screen or at the four extreme corners of the viewing field.

When the central field is examined, the field of view can be limited to certain meridians suitably chosen according to clinical dimensions or scientific requirements. The obtained one-state value is compared with a table of reference values stored in the computer, and the obtained correlation value is announced to the operator.

The angular analysis can be modified to obtain larger or smaller details of the defined area of the field of view. If retinal sensitivity is lost due to treatment hyperthermia, the analysis is increased at the edge of the blind spot to facilitate limit determination.

A graphical display is obtained by a console monitor or printer in the form of a density map. This density map can be obtained by a printer in a gray scale indicating the degree of retinal sensitivity or the degree obtained from a normal shape, or it can be obtained by showing the sensitivity of different points of meridian or latitude on the x-y axis system. .

Regarding acumetry techniques, the device of the present invention uses the smallest possible means of divisibility and is determined automatically and 441 time to the patient with the same angular visibility. For this reason brightness stimulus points appear on the screen. The spacing of these stimulation points can be moved apart or closer together by pressing the sensor to the extent that the operator sees double or single stimulation points, and these values are relayed to the computer. Measurements of visual acuity can be carried out in any examination area of the visual field and can therefore be limited to the meridian.

At the end of the examination, a graph of the acuity values, a graph of the anatomical distribution of the retina by zone 61 or meridian, etc. is obtained on the console monitor or printer.

The results obtained are compared with standard values stored in the computer to obtain normal statistical criteria.

As an adaptation technique, the device according to the invention determines the values of local dark adaptation to light and their anatomical distribution on the retina.

Adjustment of the retinal photoreceptor is achieved by using a fixed supra-umbral luminance over time.

Recalibration of the photoreceptor by progressively reducing the brightness of the stimulus point determines a positive response of the subject in time and accumulates the perceived value of the stimulus point as a function of time. Scotopicity is performed by region or by meridian, and the results are displayed on a screen or by printer, similar to other diagnostic techniques, and compared to a table of normal values.

Concerning the optokinetic technique, the device of the present invention is capable of detecting small horizontal, vertical or diagonal movements that occur on the screen as brightness stripes of variable angular spacing and width, which are observed as so-called optokinetic nystagmus. . The positive response of this movement is visually detected by repetitive eye movements. Additional detection of responses on the electronic ocrograph can be obtained from the microprocessor and peripherals to evaluate and record eye movements.

Finally, with regard to fusional criticality/iK, the device of the present invention generates intermittent stimulation points on the screen whose shape, size, brightness, color, and frequency are controlled by programming, and also by programming. The fusion frequency value is measured at an appropriate meridian, which can be selected by the focal region on the retina. Its result J4! : appears on the monitor screen and (d printer) and is automatically compared with a table of normal values for each case.

The device according to the invention has the additional advantage of being easy to handle. As a result, the operator assisting the patient has an advantageous arrangement of horizontal key consoles, video monitors, and alphanumeric manual devices* that allow him to interact with the computer and determines the examination techniques to be used. You can select any option that differs in function and view the details of the examination process at the same time.

The results of any examination are displayed on the console monitor screen in graphical or alphanumeric format according to pre-added options.

The console can be equipped with a stand-up printer, which can print graphs or alphanumeric characters corresponding to patient data or examination results.

The following detailed description of the present invention will be disclosed with reference to the accompanying drawings f'j, which merely show one example of the present invention and should therefore be construed in a limiting manner. Of course not.

Referring first to FIG. 1, central processing unit (OPU) block IA is shown. This diagram shows microprocessor 1. T(AI.A 2 and PROM 3 storage modules and instruction decoder 4 are shown.

The monitoring, data and control channels are buffered by connection modules 5 and 6.

As will be clear to those skilled in the art, the microprocessor 1 is responsible for the execution of programs contained in either of the memories 2 and 5. RAM memory 2 has a capacity of 4 kilobytes, and EPROM memory 3 has a capacity of 8 kilobytes.

The central processing unit also includes logic circuitry that monitors eight inputs and outputs (microprocessor machine cycle distribution) that allow timed distribution operations to both memory modules, a decoder 4, and the video circuit. I'm here.

FIG. 2 is a block diagram of the video generator.

This figure shows the built-in circuit 7 used as a controller for the cathode ray tube, so that the circuit has horizontal and vertical synchronization outputs. This figure further surrounds said controller circuit 7 and shows that l! , 1. Includes additional circuitry as below. That is, 111J p-lock 8; this is a phase-locked loop (P
LT, ) and formed as a frequency division chain,
The signal is generated in synchronization with the clock of the microprocessor 1, allowing the use of memory gaps or spaces in multiple uses in conjunction with the microprocessor clock.

In this way, the CRT controller 7 operates unambiguously with respect to the microprocessor 1 without any delay or overlap (the machine cycles of the microprocessor are divided into two cycles, one for the microprocessor 1 and one for the operation of the controller 7). It is divided into two parts for reading purposes).

One-time logic circuit; this is formed in such a way that it can be started together with the controller 7 by the desired scanning program. Diagrammatically, it is formed with a resolution of 340 x 246 points. The set of characters required for an alphanumeric sweep is lPRO
M memory 9 and further includes additional logic circuitry 10 necessary for deriving the graphic and alphanumeric video mixture signal for output to the second monitor, as well as the erasure signal, the graphic and alphanumeric video signal. Video Output, includes the input/output set used in generating inverted video signals for two monitors with independent control signals.

- alphanumeric memory 11; sufficient memory space for programmed alphanumeric formations still with gaps;

- 3-state drivers 12 and 13; these are needed to read alphanumeric and graphical storage from the CRT controller 7. They also allow reading and writing of the same memory interval from the microprocessor 1 by the distribution of machine cycles described above. The enable outputs of these drivers are controlled by the video clock and read/write lines.

A corresponding instruction decoder 14; this circuit is also included.

It consists of various circuit elements such as.

FIG. 3 shows a block diagram of a portion of the video mixer. This part performs the generation and shaping of different video signals for patient examination monitoring. These signals are as follows.

Generation of a fixation point; this function is performed by the built-in circuit 15. The generated fixation points can be placed arbitrarily at any point in the examination area, and they can also be of variable generation, thereby allowing central and marginal examinations to be monitored. The special occurrence of four dots placed at the edges of a square in the center of the screen allows blind spots to be observed within the same center of the examination area.

The presence and style control of these points is done through programming.

- Test, change of stimulation point brightness; the combination of digital/analog converter 16 and tube responsiveness allows a shift of the luminous flux of this stimulation point in the L direction over 10000:1. By programming 40 points of different brightness can be graduated between all these values, from 0.1 to 1.
It can be adjusted on a logarithmic scale up to 000 avostilbe.

Furthermore, these values can be superimposed onto the background brightness.

Control of the beak brightness W''I: This can also be implemented by clever programming and by means of the digital/analog converter 17, which allows the background brightness to be precisely adjusted to the required value.

Buffering: Built-in circuitry 18 provides buffering of the horizontal and vertical synchronization pulses, as well as buffering of the graphics video signal of the patient examination monitor.

FIG. 4 shows a circuit diagram of the video output amplifier.

In this case, similar specific performances can advantageously be achieved due to the special properties of this amplifier.

The iIJ amplifier provides electrical excitation of the diagnostic monitor tube cathode, and the amplifier has the ability to convert and suitably apply a set of currents into a cathode signal. The current is applied to transistor 19. The amplifier can be divided into four distinct parts as shown below.

- Amplification of test stimulus point @: This is transistor 20.21
and 220 sets.

This circuit set receives two different signals consisting of voltages emanating from a stimulus point digital/analog converter 16. The output of converter 16 is applied to a transistor 22 and produces a current proportional to the voltage. A current is thereby supplied to the transistor 21 and converts the current formed in the groin to the diagnostic graphic video rate 1↓t.

- amplification of the gaze point pulse: this amplifier is a transistor 25
The maximum current is supplied to the transistor 19 when a gaze point pulse occurs.

- amplifier of the gastric dilation current: this amplifier is formed by a working amplifier 24 and a vertical P''i T-type transistor 25; generates a current proportional to said signal applied to said signal.

- Extinguishing transistor: consists of a transistor 26, the function of which is to replace the current supplied into the transistor 19 by the presence of an extinguishing pulse.

The device f described above has a series of advantages over known devices, as listed below.

Interaction between a patient and a patient: For this purpose, the device has a suitable keyboard or manual operation, preferably with 24 functionally keyed keys in the socket, as well as It has two cathode ray tubes to establish interaction between the doctor and the patient's examination operation.

The patient's monitor preferably operates in a graphical manner, while the physician's monitor can view alphanumeric and graphical data simultaneously.

- Simple operation: Operation is essentially determined by the aforementioned working routine and direct programming via keyboard or manual operation, and by automatic monitoring of the patient's response.

If the -1W parsimony process is selected, physician intervention is completely unnecessary.

~ 4-way: All the sub-circuits of the device are modular type and can be set as plug-in cards, so the AM can perform different types of tasks and calculations by adding programming modules. be able to.

- High color resolution; Graphic sweep is suitable for examination procedures...]
It is possible to supply 540 horizontal points and 240 vertical points to
This is estimated to be 87,000 points, which means a resolution limit of 0.2 square degrees.

Printing of results: The conclusion of the consultation as well as the data required by the doctor can be printed out automatically and graphically at the end of the consultation.

- Communication capabilities: suitable interface devices can transmit the results or results to the central computer.

- Reduced maintenance and repair costs: All electronic circuits of the device are of a modular type, making card insertion easy and quick. A programming module with diagnostic routines makes it easy to isolate damaged areas or circuits.

In many cases, technical assistance in repairing certain faults is not required.

Although embodiments of the invention have been described for the purpose of disclosing the principles of the invention, many modifications, substitutions of parts of the device receiving similar protection, types of parts used, etc. may be made without departing from the spirit of the invention. , or other changes are possible.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a central processing unit (OPU). FIG. 2 is a block diagram of the video generation circuit. FIG. 3 is a block diagram of a portion of the video mixer. FIG. 4 is a circuit diagram of the video output amplifier of the present invention. The correspondence of main reference symbols in the figure is as follows. 1: Microprocessor 2: RAM 3: EPROM 4: Instruction decoder 5.6: Buffer stage 7: Built-in circuit 8: Control clock 92. Memory 11: Alphanumeric memory 12. 13: 3-state driver 14: Instruction decoder 16. 17: Digital/analog converter 19.
20.2j, 22, 25: Transistor 24: Working amplifier 25: FET transistor 26: Transistor Spain Spain Laguna 7 Tenerife El Corral Nummar 8 Inventor Juan Ignacio Partos Baratina Guimar, Spain Tenerife Finnish Molina Aba - 1-3 ■■ Inventor Pedro Navarro Yamas Spain Sunta Cruz de Tenerife Edeif Isla de Tenerife 7 - Isda Cirso de・Molina Numma 7

Claims (1)

[Claims] (1) Diagnosis and practice in the fields of ophthalmology, neurological biology, and neurophysiology! Inspection of plaster, used for clinical examination: (7) Execute programs contained in RAM (2) and F, FROM (3) type memory modules. A microprocessor (1) and an instruction decoder (
4) and a central processing unit (OPU) having means (5, +5') for buffering the monitor, data and control channels; (a) horizontal and vertical synchronization output for control of the cathode ray tube; A video generator comprising: (a) a control clock (8);
'b), time logic circuit and (C), alphanumeric memory (
11) and (al, 3-state driver (12°16
), and (e) a necessary instruction decoder (14);
(a), the control clock (8) forms a phase-locked loop (PI, I, ) and a frequency division chain, and is adapted to generate a signal synchronized with the microprocessor clock (1) of the OPU. consists of
(b) The 4-hour logic circuit is configured to control the controller circuit (7) by programming the desired scan or sweep.
It is formed in such a way that it is started with 340 x 256 points in terms of graphical resolution, while alphanumeric characters are used in memory (9) such as FiPR and OM (9). 2, and the logic +tp+ path has independent control over the rounding of the two monitors and has the additional logic necessary for graphical and alphanumeric video and inverse video mixing. ), alphanumeric memory (11)
is used for programmed alphanumeric formation, said (d) three-state driver (12, 13) is used for reading alphanumeric and graphical memory from the tube controller circuit (7); In addition, a microprocessor (1
) a video generator configured to be used for reading and writing at equal intervals from
Part of a video mixer for generating and shaping different video signals for patient examination monitoring, comprising:
), a built-in circuit (15) that generates so that the gaze point can be arbitrarily present in any examination area and can be generated in a variable manner, and (1) the luminous flux value of one stimulation point. (C) means consisting of a combination of a digital/analog converter (16) and a tube responsivity for varying the light ji of the test stimulation point such that the variation is greater than 10000:1; (C) according to programming; and (d) a digital-to-analog converter (17) to control the background brightness and accurately adjust the background brightness, and (d) to buffer the horizontal and vertical synchronization pulses as well as 1% of the patient examination monitor! a part of a video mixer having a built-in circuit (18) for buffering the video signal; An apparatus for visual field examination and calculation, characterized in that it comprises the following elements: a video output amplifier capable of converting; (2) In the device according to claim 1,
The video output amplifier consists of 5 (3 transistors) for amplification of 11 test stimulus points (
20, 21, 22), and one of the transistors has one signal connected to the digital/analog converter (16).
) is applied to a transistor (22) and converted into a current proportional to the former, which current is fed to an additional transistor (19) which determines the stimulation point brightness, the other signal being (1) for the amplification of the fixation point pulse; , a transistor (
Part 23); (1111 V*current amplifier 4 consists of a working amplifier (24) and a transistor (25), and the signal generated from the digital/analog converter (17) is the former FM The part where the signal is converted into a current proportional to the excitation transistor (19) of the tube cathode and is supplied to the excitation transistor (19) of the tube cathode; A device comprising four parts: an erased part consisting of a transistor (26) to be replaced; Said device having a color resolution limit of .degree.