KR20120132801A - Apparatus and Method for Testing Contrast Sensitivity - Google Patents

Abstract

PURPOSE: A device and method for measuring contrast sensitivity are provided to improve the safety of a driver at night by accurately measuring the contrast sensitivity of an aged driver and giving a warning to the aged driver. CONSTITUTION: A controller(110) executes a contrast sensitivity measuring program. The controller includes a space frequency correction unit(112) by distance and an average contrast threshold calculator(114) by age. A display unit(120) includes a touch panel for the user interface. An examinee response input unit(130) inputs a response for a visual stimulus by operating a remote controller. A visual target generator(140) generates a three primary color contrast sensitivity visual target and a complementary color contrast sensitivity visual target. [Reference numerals] (110) Controller; (112) Space frequency correction unit by distance; (114) Average contrast threshold calculator by age; (120) Display unit; (130) Examinee response input unit; (141) Black and white contrast sensitivity visual target generator in light; (142) Black and white contrast sensitivity visual target generator in dark; (143) Three primary color visual target generator; (144) Complementary color contrast sensitivity visual target generator; (145) Visual target generator during measuring eyesight; (151) Black and white contrast sensitivity measuring graph generator in light; (152) Black and white contrast sensitivity measuring graph generator in night; (153) Three primary color contrast sensitivity measuring graph generator; (154) Complementary color contrast sensitivity measuring graph generator; (160) Examinee test distance measuring part

Description

Apparatus and Method for Testing Contrast Sensitivity

The present invention relates to an apparatus and method for measuring contrast sensitivity, and more particularly, to an apparatus and method for measuring contrast sensitivity that can measure contrast sensitivity comprehensively in black and white contrast and color contrast for cows. will be.

Visual acuity testing is most commonly used as a clinical measure of visual function. Recently, however, the Contrast Sensitivity Test (hereinafter referred to as CST) has been widely used as an important secondary test of visual acuity test.

Visual acuity tests measure the eye's ability to resolve fine details, but the ability to see large, low-contrast objects, such as the face, is not sufficiently visible. Many diseases can cause vision loss that is not detected by common methods such as Snellen's vision. Visual acuity is nearly normal in visual dysfunction such as cerebral abnormalities, optic neuritis, glaucoma, diabetic retinopathy, and amblyopia associated with multiple sclerosis, but contrast sensitivity may be reduced.

Since subjective discomfort of visual function is often accompanied with abnormal contrast sensitivity, the patient's contrast sensitivity can be routinely measured to supplement the visual examination and complete a diagnosis or replace the visual examination.

Visual acuity tests can only test visual function at high contrast, whereas contrast sensitivity tests can assess visual function extensively for various sizes and contrasts. Therefore, the contrast sensitivity test is a method of measuring the ability to actually recognize an object, which is more complete than the vision test, and thus can be applied in various clinical applications.

The traditional method of measuring contrast sensitivity is the chart method, but the chart method has a high possibility of responding by memorizing each pattern, making accurate measurement difficult. To improve this, Vistech Consultants, Inc. Product name Multivision Contrast Tester 8000 and US Stereo Optical co., Inc. Contrast sensitivity measuring devices such as the company's trade name Optec 6500 were commercialized, but were expensive and inconvenient to use.

Meanwhile, Korean Patent Laid-Open No. 2001-1615, Japanese Patent Laid-Open No. 2003-204936, US Patent Publication No. 2003/0174284 and the like disclose a technique for displaying a slide on which a black stripe pattern is displayed on a white background on a monitor.

Conventional technology adopts a contrast sensitivity measurement method in the light test by simply changing the contrast of black stripes from black to white in a black striped pattern on a white background.

However, as the number of older cars has increased due to the increase in the elderly population, the traffic accident rate by the elderly has been increasing.

Older people have decreased vision as they age, but are more likely to lose their ability to contrast with retinal diseases such as cataracts, glaucoma, Alzheimer's disease, macular degeneration, or diabetes. The risk of causing it increases.

However, in the current Ming Dynasty, the measurement of the contrast sensitivity alone has a limitation that it is impossible to measure the contrast sensitivity ability caused by various causes more accurately.

An object of the present invention for solving the above problems is to provide a contrast sensitivity measuring device and method capable of comprehensively measuring the contrast sensitivity to black and white contrast and color contrast at the time of black-and-white contrast.

Another object of the present invention is to provide an apparatus and method for measuring a contrast sensitivity, which can calculate an average contrast threshold for each age in order to detect a fast contrast threshold and use the calculated average contrast threshold as a test starting value.

In order to achieve the above object, the device of the present invention is a liquid crystal monitor for displaying a black and white contrast sensitivity table, a black and white contrast sensitivity table, a three-color contrast sensitivity table, and a complementary color contrast table, and a measurement mode. Remote control for inputting the response to the subject's stimulus by looking at the marks displayed on the mark, and the mark generator for generating black and white contrast sensitivity marks, black and white contrast sensitivity marks, three primary color contrast marks, and complementary color contrast marks at the time of sight Black and white contrast sensitivity measurement graph, Cow city black and white contrast sensitivity measurement graph, Three primary color contrast sensitivity measurement graph and Complementary color contrast sensitivity measurement graph generation unit One of the black and white contrast sensitivity measurement mode, the three primary color contrast sensitivity measurement mode, and the complementary color contrast sensitivity measurement mode When selected by the remote controller, the target corresponding to the selected measurement mode is received from the target generator and displayed on the monitor, the test subject's response to the displayed target stimulus is input through the remote controller, and the input subject's response information is input to the measurement graph generator. And a control unit configured to execute a contrast sensitivity measurement program for displaying the measurement graph generated by the measurement graph generator on the liquid crystal monitor.

In the present invention, the target means a slide on which one pattern is displayed for measuring contrast sensitivity. That is, it is different from the chart in which various patterns are displayed at the same time. Therefore, depending on the contrast level and the spatial frequency, several to several dozen slides are provided as an index composed of one screen.

In the present invention, the target generating unit gradually increases or decreases the contrast of the stripe pattern at the spatial frequency of each step in response to the testee's response information at each step of the spatial frequency, and generates the target slides, respectively, and the control unit corresponds to the response information of the testee. The contrast sensitivity threshold is determined at the spatial frequency and the determined contrast sensitivity threshold is provided to the measurement graph generator.

In addition, the target generation unit is generated by randomly changing the inclination of the stripe pattern at the spatial frequency of each step while changing the spatial frequency of the stripe pattern step by step.

In addition, the complementary contrast sensitivity indicator generating unit preferably generates a contrast sensitivity indicator of red-cyan, blue-yellow and green-purple, respectively.

The apparatus may further include an eye measurement target generator, and the controller may receive the eye measurement target from the eyesight measurement generator and display it on the liquid crystal monitor when the eyesight measurement mode is selected by the remote controller.

In the present invention, it is preferable that the controller corrects the spatial frequency in response to the distance value of the liquid crystal monitor and the examinee.

The apparatus of the present invention for achieving the above object is a method for measuring the contrast sensitivity checks the contrast sensitivity of the sight spot by the response input of the subject corresponding to the sight sensitivity contrast spot presented on the monitor, the contrast sensitivity of the cow presented on the monitor The contrast sensitivity is inspected by the response input of the subject corresponding to the target, and the color contrast sensitivity is examined by the response input of the subject corresponding to the color contrast sensitivity presented on the monitor. Displays the results of the color contrast test on the monitor.

The device according to an embodiment of the present invention can secure safety when driving at night by accurately measuring the contrast sensitivity of older drivers and giving treatment and attention.

1 is an external perspective view of a preferred embodiment of the contrast sensitivity measuring apparatus according to the present invention.
2 is a block diagram of a contrast sensitivity measuring apparatus according to the present invention.
3 is a view showing a slide change in the state of changing the contrast to 50% at the time of sight.
4 is a view showing a slide state in which the inclination of the stripes is inclined at -30 ° and 30 ° at a sight condition of 50% contrast.
Fig. 5 shows the slide change in the state where the contrast is changed to -50% in the dark state.
6 is a view showing the change of the slide with the contrast of the three primary colors changed to 50% at the time of sight.
7 is a diagram illustrating a complementary color relationship with respect to three primary colors.
8 is a view showing the change of the slide with the contrast of the complementary colors changed to 50% at the time of attraction.
9 is a black and white contrast sensitivity measurement graph at the time of sight.
10 is a black and white contrast sensitivity measurement graph.
11 to 13 are three primary color contrast sensitivity measurement graphs.
14 to 16 are complementary color contrast measurement graphs.
17 is a flowchart illustrating a contrast sensitivity measurement method according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in more detail with reference to the accompanying drawings. The present invention is capable of various modifications and various forms, and specific embodiments are illustrated in the drawings and described in detail in the text. It is to be understood, however, that the invention is not intended to be limited to the particular forms disclosed, but on the contrary, is intended to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

When the human eye sees, the visual perception information visually obtained is transmitted to the brain to recognize it. For example, when looking at the face, visual functions such as shape, color, and size are transmitted to the brain through their respective spatial frequencies and magnocellular pathways. . At this time, each face can see a clear or blurred image depending on the contrast of visual function.

In other words, contrast refers to the ability to distinguish objects from the background. By measuring the contrast sensitivity, each eye is measured by how bright, dark, and clear the image is. Provide important data for your treatment.

The human eye enters light through the eye that hits the object, which is one of the photoreceptors in the retina (cone: red wavelength M-cone, green wavelength L-cone, blue wavelength S-). collected by a cone, and converted into an electrical signal, the object's shape, color, shape, and degree of movement are transmitted to the brain along the visual and perceptual path to be recognized. The color path recognized by the eye is accepted as the wavelength of the basic tricolor color in the photoreceptor, thereby recognizing the color sense. In other words, it is determined along the path of black red, green, blue (major tricolor) yellow, purple, and cyan (tricolor contrast color) white, where light is not received, which is one of the photoreceptors. Since each person's quantity, distribution and performance differ slightly from person to person, each person's contrast sensitivity is not only black and white, but also the main three colors.

Therefore, in the future, not only the contrast of black and white, but also the sensitivity of the main three colors can play an important role in measuring the overall contrast.

When the test subject has low contrast sensitivity, it is difficult to see a pedestrian walking along the roadside of a dim street light, and there is a problem when driving at night. In addition, the examinee with low contrast sensitivity needs a separate light when reading, and the examinee's eyes become more tired when reading or watching TV. Low contrast sensitivity may be a symptom of eye disease and may be caused by symptoms such as cataracts, glaucoma or diabetic retinopathy. Low contrast sensitivity may also be a side effect of laser vision surgery, including LASIK and PRK. However, lack of contrast is different from blurred vision.

1 is an external perspective view of a preferred embodiment of the contrast sensitivity measuring apparatus according to the present invention, Figure 2 is a block diagram of the contrast sensitivity measuring apparatus according to the present invention.

Referring to the drawings, the contrast sensitivity measuring apparatus 100 includes a support plate 102, a support 104, and a main body 106 in a stand type. The main body 106 has a rectangular shape and a monitor is disposed on the front surface, and a test distance measuring instrument 108 is installed at the top center. In the main body 106, a contrast sensitivity measuring circuit is configured.

The measurement circuit of the contrast sensitivity measuring device 100 includes a control unit 110, a display unit 120, a test subject response input unit 130, a target generator 140, a measurement graph generator 150, and a test subject test distance measuring unit 160. ).

The control unit 110 includes a central processing unit (CPU) and executes a contrast test measurement program. The controller 110 includes a spatial frequency corrector 112 for each distance and an average contrast threshold calculator 114 for each age.

The display unit 120 is configured of a liquid crystal monitor and displays various indicators (slides) provided from the controller 110. The display unit 120 may be formed with a touch panel for a user interface.

The examinee response input unit 130 includes a remote controller. Therefore, the examinee operates the remote controller in response to the pattern displayed on the monitor at a position spaced apart from the main body 106 by the inspection distance, and inputs his / her response to the visual stimulus to the controller 110.

The target generation unit 140 includes a photopic condition black and white contrast sensitivity target generation unit 141, a cow topic (Scotopic Condition) black and white contrast sensitivity target generation unit 141, and three primary colors (RGB) contrast sensitivity target generation unit ( 143), the complementary contrast sensitivity target generator 144 and the visual acuity target generator 145.

 Photopic Condition The black and white contrast sensitivity table generator 141 displays a black stripe pattern on a white background. The width and spacing of the black stripe pattern are 1, 2, 3, 4, 6, 8, Divided into 9 levels of 12, 15, and 30 cpd, black stripes are divided into 11 levels of 90, 80, 70, 60, 50, 40, 30, 20, 10, 5, and 2.5% depending on contrast A total of 99 slides are included. In addition, the inclination angle of the black stripes is -90 °, -60 °, -30 °, 0 °, 30 °, 60 °, 90 ° to distinguish the gradient of the stripes pattern in seven angles. Therefore, a combination of tilting up to 693 slide combinations is possible. 3 and 4 show the slide change at the time of sight.

When measuring the contrast sensitivity at the spot, the contrast of the band can be measured at each spatial frequency while the brightness of the stripe is gradually lowered from 100% black and the spatial frequency is changed from low to high.

Scotopic Condition Black and White Contrast Sensitivity The target generator 141 fixes the contrast in the spatial frequency, while the stripes are fixed to black and the background color between the stripes is gradually reduced from -100% white, unlike the spot. The measurements are different and the slide combinations are the same. The brightness of the base between black stripes at 11 levels of -90, -80, -70, -60, -50, -40, -30, -20, -10, -5, and -2.5% depending on contrast The changed slide occurs as a target. 5 shows the slide change in the dark. Contrast sensitivity measurement at night time is to measure contrast sensitivity at night, and it is possible to measure black and white contrast sensitivity of elderly drivers at night.

As shown in FIG. 6, the three primary colors (RGB) contrast sensitivity target generation unit 143 measures the contrast threshold for the three primary colors at each spatial frequency under the same conditions as the spot time condition described above for the red, green, and blue colors. Generate a target for.

As shown in FIG. 7, the complementary contrast sensitivity indicator generating unit 144 includes red-blue-green, green-magenta, and blue-yellow complementary colors. As shown in FIG. 8, a target for measuring the contrast threshold for the complementary color at each spatial frequency is generated under the same conditions as the above-mentioned spot viewing condition for the complementary colors.

The vision measurement target generator 145 generates a typical vision measurement target. Measurement graph generation unit 150 is a black and white contrast sensitivity measurement graph generation unit 151 when spots, black and white contrast sensitivity measurement graph generation unit 152 when cows, three primary color contrast sensitivity measurement graph generation unit 153, complementary color sensitivity measurement It includes a graph generator 154.

Spot black and white contrast sensitivity measurement graph generation unit 151 generates the measurement graph of Figure 9, black and white contrast sensitivity measurement graph generator 152 generates the measurement graph of Figure 10, three primary color contrast sensitivity measurement graph The generator 153 generates the measurement graphs of FIGS. 11 to 13, respectively, and the complementary color sensitivity measurement graph generator 154 generates the measurement graphs of FIGS. 14 to 16, respectively.

Contrast sensitivity measurement method according to the invention configured as described above is as follows.

17 is a flowchart illustrating a contrast sensitivity measuring method according to the present invention.

Referring to the drawing, a contrast sensitivity measurement mode is set by pressing a menu displayed on a monitor or a menu selection key installed on a remote controller.

First, the age of the examinee is input through the remote controller 130 in the contrast sensitivity measurement mode (S100). The controller 110 retrieves an average contrast threshold according to the calculated age. Subsequently, the test distance measuring unit 160 measures and sets the distance between the test subject and the monitor (S102). Subsequently, the visual acuity measurement table provided from the visual acuity measurement target generation unit 145 is displayed on the monitor to measure the visual acuity of the subject and store the measured visual acuity value (S104). In response to the measured distance and visual acuity, the controller 110 corrects the interval and width of the stripe pattern of the target displayed on the monitor 120 through the spatial frequency correction unit 112 for each distance (S106).

When the stripe pattern is corrected, the spatial frequency is sequentially changed in 9 steps of 1, 2, 3, 4, 6, 8, 12, 15, and 30, and the spatial frequency index is set to 1 to measure the contrast threshold at each spatial frequency. 1cpd is set (S108).

When the spatial frequency is selected, it is preferable to display a stripe pattern having a certain contrast, preferably, a contrast pattern corresponding to the average contrast threshold corresponding to the input subject's age as an initial value (S110). This average contrast threshold may be updated to a new average contrast threshold by applying the newly measured contrast threshold to the existing average every time the measurement is completed. If there is no such average value, an existing experiment reported value or an intermediate value may be applied as a contrast value to be initially displayed.

When the examinee sees the initial slide pattern and inputs a response to the visual stimulus using the remote controller, the controller 110 processes 'yes' if the contrast pattern is well seen and 'no' if the contrast pattern is not visible (S112). If yes in step S112, the flag bit value F = 1 is set (S114). If 'no', the flag bit value F = 0 is set (S120).

Then, it is checked whether the flag bit value is converted from 0 to 1 (S116) or 1 to 0 (S122).

If there is no change in the flag bit value in step S116, a slide in which the current contrast value is lowered by one step is displayed (S118), and the flow returns to step S112. If there is no change in the flag bit value in step S122, a slide in which the current contrast value is increased by one step is displayed (S118), and the flow returns to step S112. That is, if the current contrast pattern is visually recognized, the contrast pattern is displayed with lower contrast, and if the current contrast pattern is not visually recognized, the contrast pattern is displayed with higher contrast.

If there is a change in the flag bit value in step S116, since the contrast pattern is not recognized or recognized, the recognized current contrast value is determined and stored as the contrast threshold of the corresponding spatial frequency (S126).

If there is a change in the flag bit value in step S122, since the contrast pattern is recognized but not recognized, the recognized previous contrast value is determined and stored as the contrast threshold of the corresponding spatial frequency (S128).

Repeat steps S108 to S130, which are contrast threshold measurement loops, by increasing the spatial frequency index by 1 for the spatial frequencies 1, 2, 3, 4, 6, 8, 12, 15, and 30, respectively, to perform each space in step 9 When the contrast thresholds are obtained for the frequencies, the controller 110 provides the obtained thresholds to the measurement graph generator 150 to generate the measurement graphs of FIGS. 9 to 16, respectively (S132).

Therefore, it is possible to measure very easily and quickly about spot conditions, dark conditions, three primary color contrast conditions, and complementary color contrast conditions, so that accurate contrast sensitivity can be measured.

The test results can help determine whether a vision lens or special lens is needed for vision errors known to the subject's eye disease and high-order aberrations. It is best to wear corrective glasses made with a yellow filter to improve contrast when diagnosed as having low contrast sensitivity.

Claims (9)

A liquid crystal monitor for displaying spot-time black and white contrast sensitivity charts, cow-time black and white contrast sensitivity charts, three primary color contrast sensitivity tables and complementary color contrast sensitivity tables;
A remote controller for selecting a measurement mode and inputting a response to a subject's visual stimulus by viewing a target displayed on the display unit;
A mark generator for generating the spot black and white contrast sensitivity table, the black and white contrast sensitivity table, the three primary color contrast sensitivity table, and the complementary color contrast sensitivity table;
A measurement graph generator for generating black and white contrast sensitivity measurement graphs, black and white contrast sensitivity measurement graphs, three primary color contrast sensitivity measurement graphs, and complementary color contrast sensitivity measurement graphs; And
When one of the measurement modes is selected by the remote controller, one of the black and white contrast sensitivity measurement mode, the black and white contrast sensitivity measurement mode, the three primary color contrast sensitivity measurement mode, and the complementary color contrast measurement mode are selected. Received from the target generation unit and displayed on the monitor, input the response of the subject to the displayed target stimulation through the remote control, and provides the input subject response information to the measurement graph generator, the measurement graph generator And a control unit for executing a contrast sensitivity measurement program for displaying the generated measurement graph on the liquid crystal monitor. The method of claim 1, wherein the target generator generates a target slide by gradually increasing or decreasing the contrast of the stripe pattern in response to the testee's response information at the spatial frequency of each stage while gradually changing the spatial frequency.
And the controller determines a contrast sensitivity threshold at a corresponding spatial frequency among response information of a subject and provides the determined contrast sensitivity threshold to the measurement graph generator. The apparatus of claim 1, wherein the target generation unit is generated by randomly changing the slope of the stripe pattern at the spatial frequency of each step while gradually changing the spatial frequency of the stripe pattern. The contrast sensitivity measuring apparatus according to claim 1, wherein the complementary contrast sensitivity indicator generating unit generates a contrast sensitivity indicator of red, cyan, blue, yellow, and green. The apparatus of claim 1, wherein the apparatus further comprises an eye measurement target generator, and wherein the controller is configured to receive an eye measurement target from the eye measurement target generator and display it on the monitor when the eye measurement mode is selected by the remote controller. Contrast sensitivity measuring device, characterized in that. The apparatus of claim 1, wherein the controller corrects a spatial frequency in response to a distance value of the liquid crystal monitor and the examinee. Checking the contrast sensitivity of the sight spot according to a response input of a subject corresponding to the sight sight contrast sensitivity index presented on the monitor;
Inspecting the contrast sensitivity of the cow by a response input of a subject corresponding to the cow contrast contrast table presented on the monitor; And
Contrast sensitivity measurement method characterized in that it comprises the step of displaying the contrast sensitivity measurement results of the sight time and cow time of the subject on the monitor. Checking the contrast sensitivity of the sight spot according to a response input of a subject corresponding to the sight sight contrast sensitivity index presented on the monitor;
Inspecting color contrast sensitivity according to a response input of a test subject corresponding to a color contrast sensitivity index presented on the monitor; And
Contrast sensitivity measurement method characterized in that it comprises the step of displaying on the monitor the sight time and color contrast sensitivity test results of the subject. Checking the contrast sensitivity of the sight spot according to a response input of a subject corresponding to the sight sight contrast sensitivity index presented on the monitor;
Inspecting the contrast sensitivity of the cow by a response input of a subject corresponding to the cow contrast contrast table presented on the monitor;
Inspecting color contrast sensitivity according to a response input of a test subject corresponding to a color contrast sensitivity index presented on the monitor; And
Contrast sensitivity measurement method characterized in that it comprises the step of displaying on the monitor the spot time, the cow time and the color contrast sensitivity test results of the subject.

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