CN1827035A

CN1827035A - Method for reducing examinee subjective error in visual field examination and relevant apparatus

Info

Publication number: CN1827035A
Application number: CN 200610067167
Authority: CN
Inventors: 赵阳
Original assignee: Individual
Current assignee: Individual
Priority date: 2006-04-06
Filing date: 2006-04-06
Publication date: 2006-09-06

Abstract

This invention belongs to ophthalmology medical service instrument, and it discloses a method for reducing observers' subjective error in visual field test and the relative set. The set is composed of light source, vidicon, calibration plate and computer image processing system. Judge whether observers see cursor by computing whether observers' sight angle matches cursor position. This can advance reliability of visual field test result and shorten test time.

Description

Reduce the method and the relevant apparatus of examinee's subjective error in the perimetry

Technical field:

The invention belongs to the ophthalmic medical instrument field, a kind of specifically method and relevant apparatus that reduces examinee's subjective error in the perimetry.

Background technology:

To be that ophthalmology and department of neurology are commonly used check perimetry, be widely used in glaucoma early, the diagnosis in mid-term, the function damage evaluation that fundus oculi disease and nervous system disease cause.At present clinical the most frequently used be automatic perimeter, require the examinee to watch the dead ahead target attentively always, hand-held button, perimeter is at the glittering at random cursor of periphery and central authorities, and is glittering if the examinee notices cursor, then clicks button as replying, otherwise not according to.If cursor is glittering and the examinee replys, then perimeter judges that the examinee can see cursor, and the examinee does not reply if cursor is glittering, and then perimeter judges that the examinee can not see cursor.Automatically perimeter is a kind of subjectivity inspection, and it needs those who are investigated's cooperation just can finish, and it is glittering and the examinee replys not have cursor sometimes, and then perimeter is designated as the false positive mistake one time.If in the site of measuring lightsensitivity, giving strong cursor once more stimulates, and examinee's no response is designated as False negative error one time.Button is too quickly, lifts by Bi Wei, and checking process is not understood, and factors such as button bradykinesia are the main causes that leads to errors, and the reliability that false positive mistake or False negative error can reduce check result occurs.False positive and False negative error are reduced in the same site of the many employings of automatic perimeter repeatedly retest, and this has also increased the review time simultaneously.Automated perimetry needs those who are investigated's eye, hands, brain to cooperate simultaneously, for youngster with often carry out for the people of three cooperation, is not difficult matter, otherwise, just need and will prompting those who are investigated repeatedly note main points, even reexamine again.Studies show that: whether those who are investigated had factors such as the experience, age, schooling of perimetry relevant with the perimetry result.Along with empirical abundant, those who are investigated's visual field result levels off to itself retina visual acuity more.The patient of, initial examination low for older while schooling will repeatedly train, and improves the reliability (2002 the 16th volumes of " individual variation is to the influence of the automatic perimeter check result of computer " south China national defence medical journal) of check result as far as possible.Unreliability is detected in the visual field will have influence on the explanation of clinicist to visual field testing result, thereby reduce the clinical value of this detection method.And traditional automatic perimeter requires the examinee to look admittedly some the eyes long period when checking, eyes are in tension, and is very easily tired, dim eyesight occurs, also can influence check result.

Summary of the invention:

The object of the present invention is to provide a kind of objective examinee of judgement whether to see the method for cursor,, improve perimetry result's reliability to solve the bigger problem of examinee's subjective error that existing inspection method exists.

The present invention takes following technical scheme:

When head maintains static, with secondary light source irradiation human face, form reflection image at the eye cornea, be called the pul speckle of admiring again, itself and the skew of pupil and iris and the direction of eye sight line have linear relationship one to one.With video camera picked-up eyes image, calculate the admire position relation of speckle and pupil and iris of pul in institute's pickup image by the Computer Image Processing instrument, computer image processing technology is ripe public technology: suppose that the admire position coordinates of speckle of pul is (Xp, Yp), the position coordinates at pupil and iris center be (Xt, Yt), the angle of sight line horizontal direction is M, the angle of vertical direction is N, when head maintains static, and (Xp, Yp) fixing, when eyeball rotated, (Xt Yt) changed.Make X=Xp-Xt, Y=Yp-Yt then has M=aX+b, N=cY+d, and a, b, c, d are system's constant.At first allow the examinee watch the target at least 4 different fixing known inclination angles attentively and absorb eyes image, obtain M respectively, X, N, Y, the substitution following formula can be tried to achieve system's constant, realizes the individuation system calibration.Carry out perimetry then, setting the glittering order of perimeter cursor is the glittering central cursor of elder generation, and glittering again district to be measured cursor so repeats later on.Advise the examinee to find that cursor promptly uses the eye gaze cursor.Video camera absorbs glittering back 0.5 second ~ 1 second eyes image of each cursor (react speed according to the examinee and can suitably adjust time-delay), calculating the admire position of speckle and pupil and iris of pul in institute's pickup image by the Computer Image Processing instrument concerns, promptly calculate (Xp, Yp) and (Xt, Yt), can try to achieve M, N, be the exploded angle of sight line, judge whether angle identical or close (allowing suitable difference) with glittering cursor position in level and vertical direction.If there is the glittering and sight line that obtain through aforementioned calculation of cursor identical or close with the angle of glittering cursor position, then be judged as the examinee and see cursor, do not see cursor otherwise be judged as the examinee.

The beneficial effect that the present invention produces is: after taking technique scheme, the present invention can be objective, judges accurately whether the examinee sees cursor in the perimetry, reduces false positive and False negative error, improves perimetry result's reliability.Simultaneously, can realize that objective and accurate judgement does not then need the repeatedly retest of same site, can shorten the review time.And, avoided because of looking for a long time the visual fatigue that any causes admittedly.

The invention will be further described below in conjunction with drawings and Examples.

Description of drawings:

Fig. 1 is the structural representation of apparatus of the present invention

Fig. 2 is whether the present invention can see the flow chart that cursor is once judged to the examinee

The specific embodiment:

Referring to Fig. 1, on the calibration plate 7 at least 4

scaling points

3,4,5,6 are arranged, central fixed light source 1 and video camera 2 are all towards the examinee.

Calibration plate 7 is apart from examinee 40cm, the positive apparent time sight line of examinee is by light source 1, light source 1 adopts the infrared LED light source, video camera 2 adopts the SE-112H B, scaling point 3 is positioned at light source 1 top 30cm, scaling point 4 is positioned at light source left side 30cm, and scaling point 5 is positioned at the right 30cm of light source, and scaling point 6 is positioned at light source below 30cm.

Please refer to Fig. 2, it shows judges whether the examinee can see the embodiment of the flow process of cursor.

Should be noted that, profile that can modifier under the situation that does not break away from basic design disclosed herein and some detail sections, and under the situation that does not break away from basic design disclosed herein, can change each step of method.

Claims

1, a kind of device that reduces examinee's subjective error in the perimetry, it is characterized in that: by light source, video camera, calibration plate and Computerized image processing system are formed, described light source is according to forming flare to examinee's eyes at anterior corneal surface, described video camera is taken eyes image, on the described calibration plate a plurality of scaling points are arranged, described Computerized image processing system calculates captured image, described video camera is taken the tested eye image of watching scaling point attentively and the image of watching cursor attentively respectively, and described Computerized image processing system is handled image and judged whether sight line conforms to the cursor position.

Whether 2, a kind of method that reduces examinee's subjective error in the perimetry conforms to cursor position by the angle of calculating examinee's sight line and to judge whether the examinee sees cursor, and this method comprises the following steps:

The examinee watches a plurality of scaling points attentively, and video camera absorbs eyes image respectively;

Computerized image processing system calculates the position relation of flare and pupil and iris and the relational expression of sight angle according to the above-mentioned eyes image that absorbs;

Glittering central cursor, the 0.5 second picked-up eyes image of delaying time, the position of calculating flare and pupil and iris according to institute's pickup image concerns, imports the relational expression of being calculated and calculates the eye sight line angle;

Judge whether sight angle conforms to the angle of cursor position, then do not point out the examinee to watch cursor attentively if be inconsistent, it is rapid to repeat previous step, if conform to then glittering tested point cursor;

Delayed time 0.5 second, the picked-up eyes image, the position of calculating flare and pupil and iris according to institute's pickup image concerns, imports the relational expression of being calculated and calculates the eye sight line angle;

Judge whether sight angle conforms to the angle of cursor position, do not judge that then the examinee cannot see this measurement point cursor, judge that then the examinee can see this measurement point cursor if conform to if be inconsistent.