Method for diagnosing deficiencies in and expanding a person's useful field of view

• US 4,971,434 A
• Filed: 11/28/1989
• Issued: 11/20/1990
• Est. Priority Date: 11/28/1989
• Status: Expired due to Term

• Current Assignee: Visual Awareness Research Group Incorporated
• Original Assignee: Visual Resources, Inc.
• Inventors: Ball, Karlene K.
• Primary Examiner(s): Dzierzynski, Paul M.
• Application Number:
  US07/441,992
• Time in Patent Office: 357 Days
• Field of Search: 351/222, 351/224, 351/226, 351/203
• US Class Current: 351/224
• CPC Class Codes: A61B 3/024 for determining the visual field, e.g. perimeter types
• CPC Class Codes: A61B 3/032 Devices for presenting test symbols or characters, e.g. test chart projectors A61B3/036 takes precedence

Abstract

A method for diagnosing deficiencies in and expanding the size of a person'"'"'s "Useful Field Of View" (UFOV). The UFOV is determined by the eccentricity (in degrees of visual angle) at which peripheral targets (presented within an embedding context) can be localized 50% of the time while performing a concurrent visual task in central vision. The method provides multiple blocks of trials, each block of trials consists of displaying a plurality of times before a subject'"'"'s vision a set of four sequentially presented images having specific characteristics, and the specific characteristics of each block of trials is changed each time a new block of trials is displayed before the subject. By changing the characteristics of each block of trials, a diagnosis can be made of the subject'"'"'s vision by creating a subject database that contains the subject'"'"'s indicated responses to each block of trials having specific characteristics and comparing the subject database to a normative diagnostic database in order to achieve a diagnosis. The method also employs training programs to expand the size of the subject'"'"'s UFOV.

Claims

1. In a system for measuring and diagnosing a subject'"'"'s useful field of view (UFOV), a method comprising the steps in the sequence set forth:

(a) positioning the subject before a display screen;

(b) displaying a fixation box on a display screen to position the subject'"'"'s foveal view;

(c) displaying a foveal image on the display screen located at the center of the fixation box wherein the foveal image has a first level of discerning difficulty, superimposing on the display screen a peripheral image over the foveal image wherein the peripheral image has distractor stimuli positioned at a plurality of possible eccentricities and radial locations from the foveal image such that each of the positions is outside of the foveal view of the subject derived from focusing on the foveal image, and having a peripheral target in the peripheral image that has a first level of distinguishing difficulty from the distractor stimuli and wherein the peripheral target is located at one of the plurality of possible eccentricities and radial locations from the foveal image;

(d) removing the foveal image and peripheral image from the display screen after a first duration period and displaying on the display screen a masking image intended to suppress any afterimage created on the subject'"'"'s retina after removal of the foveal image and peripheral image;

(e) displaying on the display screen a prompt image for prompting the subject to indicate details of the foveal image and correct radial location of the peripheral target in relation to the foveal image as perceived by the subject;

(f) recording accuracy of subject'"'"'s perceived details of the foveal image and the radial location of the peripheral target as indicated by the subject; and

(g) repeating steps (b)-(f) varying the eccentricities of the peripheral target, radial location of the peripheral target, details of the foveal image, discerning difficulty of the foveal image, distinguishing difficulty of the peripheral target, and the duration period for displaying the foveal and peripheral images in order to create a database of subject'"'"'s perception ability.

(h) correlating the database with normative data to diagnose the subject'"'"'s UFOV and identify deficiencies in the subject'"'"'s visual system.

2. A method for measuring and diagnosing a subject'"'"'s UFOV as referred to in claim 1, wherein a set consists of steps (b) through (f) of claim 1.

3. A method for measuring and diagnosing a subject'"'"'s UFOV as referred to in claim 2, wherein a block of trials consists of repeating sets a plurality of times and in each block of trials only varying the eccentricities of the peripheral target, radial location of the peripheral target and details of the foveal image so as to calculate the subject'"'"'s UFOV for each block of trials.

4. A method for measuring and diagnosing a subject'"'"'s UFOV as referred to in claim 3, wherein the discerning difficulty of the foveal image, distinguishing difficulty of the peripheral target, and duration of time period for displaying the foveal and peripheral images are varied for each block of trials so as to diagnose a subject'"'"'s vision.

5. A method for measuring and diagnosing a subject'"'"'s UFOV as referred to in claim 1, wherein the radial location of the peripheral target in relation to the foveal image is one of eight alternatives consisting of 0°

, 45°

, 90°

, 135°

, 180°

, 225°

, 270° and

315°

.

6. A method for measuring and diagnosing a subject'"'"'s UFOV as referred to in claim 1, wherein the level of distinguishing difficulty of the peripheral target is altered by varying color, intensity, and design of the peripheral target in relation to the distractor stimuli.

7. In a system for improving a subject'"'"'s processing speed of visual information, a method comprising the following sequential steps:

(a) focusing the subject'"'"'s vision on a fixation box to position subject'"'"'s foveal view;

(b) displaying a detailed image at the center of the fixation box while simultaneously displaying a peripheral image from the detailed image as observed by the subject having distractors and a target image;

(c) removing the detailed image and peripheral image after displaying the images for a time period;

(d) displaying a masking image intended to suppress any afterimage created on the subject'"'"'s retina after removal of the detailed image and peripheral image;

(e) requiring the subject to identify changing characteristics of the detailed image while simultaneously locating the target image having a changing position in the peripheral image;

(f) repeating steps (a) through (e) varying the position of the target image, characteristics of the detailed image and time period for displaying images so as to calculate a minimum time period required for the subject to correctly identify a designated percentage of times the changing characteristics of the detailed image while concurrently localizing the target image;

(g) repeating steps (a) through (e) a plurality of times to calculate the subject'"'"'s UFOV and decreasing the time period for displaying the images each time the calculated UFOV exceeds a designated number of degrees until a criterion level of performance is reached.

9. A method for improving a subject'"'"'s visual deficiencies due to distractor effects as referred to in claim 7, wherein the salience of the target image is decreased by adding distractors to the peripheral image which become more and more similar to the target image.

8. In a system for improving a subject'"'"'s visual deficiencies due to distractor effects, a method comprising the sequential steps of:

(a) focusing the subject'"'"'s vision on a fixation box to position subject'"'"'s foveal view;

(b) displaying a detailed image at the center of the fixation box while simultaneously displaying a peripheral image from the detailed image as observed by the subject having a target image;

(c) removing the detailed image and peripheral image after displaying the images for a time period;

(d) displaying a masking image intended to suppress any afterimage created on the subject'"'"'s retina after removal of the detailed image and peripheral image;

(e) requiring the subject to identify changing characteristics of the detailed image while simultaneously locating the target image having a changing position in the peripheral image;

(f) repeating steps (a) through (e) varying the position of the target image, characteristics of the detailed image and time period for displaying images so as to calculate a minimum time period required for the subject to correctly identify a designated percentage of times the changing characteristics of the detailed image while concurrently localizing the target image;

(g) repeating steps (a) through (e) a plurality of times to calculate the subject'"'"'s UFOV and decreasing salience of the target image each time the calculated UFOV exceeds a designated number of degrees until a criterion level of performance is reached.

10. In a system for improving a subject'"'"'s visual deficiency due to divided attention difficulty, a method comprising the sequential steps of:

(a) focusing the subject'"'"'s vision on a fixation box to position subject'"'"'s foveal view;

(b) displaying a detailed image at the center of the fixation box while simultaneously displaying a peripheral image from the detailed image as observed by the subject having distractors and a target image;

(c) removing the detailed image and peripheral image after displaying the images for a time period;

(d) displaying a masking image intended to suppress any afterimage created on the subject'"'"'s retina after removal of the detailed image and peripheral image;

(e) requiring the subject to identify changing characteristics of the detailed image while simultaneously locating the target image having a changing position in the peripheral image;

(f) repeating steps (a) through (e) varying the position of the target image, characteristics of the detailed image and time period for displaying images so as to calculate a minimum time period required for the subject to correctly identify a designated percentage of times the changing characteristics of the detailed image while concurrently localizing the target image;

(g) repeating steps (a) through (e) a plurality of times to calculate the subject'"'"'s UFOV and increasing complexity of the detailed image each time the calculated UFOV exceeds a designated number of degrees until a criterion level of performance is reached.