US3574450A
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Method and apparatus for determining the effectiveness of spatial vision
Assignee: Individual
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Filing: 1969-05-19
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Granted: 1971-04-13
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Expires: 1989-05-19
Abstract
Abstract A method and apparatus for testing the spatial vision of a subject by obtaining averaged evoked cortical responses produced by various patterned stimuli; and by obtaining such responses produced by a subject observing a given pattern through a graded series of ophthalmic lenses. The amplitude of certain components of the evoked cortical response, occurring at specific times following the brief illumination of such patterns, vary directly with the degree of clarity of the perceived images produced by these patterns. The degree of refractive error, and other aspects of a subject''s visual characteristics, can thus be determined by finding the conditions that produce the maximum amplitudes of those specific components of the evoked response.
Inventors
- 👤 Carroll T White
- 👤 Melvin R Harter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 14:55
CPC Classifications
A; A61; A61B; A61B3/00; A61B3/10; A61B5/00; A61B5/24; A61B5/316; A61B5/369; A61B5/377; A61B5/378
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
100 words
A method for objectively determining the refractive and astigmatic errors in the spatial vision of a subject including the steps of: a. submitting the subject periodically to visual stimuli; b. placing a graded series of opthalmic lenses in succession in front of the eyes of the subject; c. measuring the evoked cortical responses of said subject to said stimulation for each lens condition; and d. comparing the amplitudes of the cortical responses obtained from each of said lenses and determining which lens produces the largest cortical response at a predetermined elapsed time after stimulation thus providing the best optometric correction.
Claim 2
Independent Claim
100 words
A method for objectively determining the refractive and astigmatic errors in the spatial vision of a subject including the steps of: a. submitting the subject periodically to visual stimuli; b. placing a graded series of opthalmic lenses in succession in front of the eyes of the subject; c. measuring the evoked cortical responses of said subject to said stimulation for each lens condition; and d. comparing the amplitudes of the cortical responses obtained from each of said lenses and determining which lens produces the largest cortical response at a predetermined elapsed time after stimulation thus providing the best optometric correction.
Claim 3
Dependent Claim
31 words
The method of claim 1 wherein the step of measuring the peaked responses at the predetermined elapsed time from stimulation occurs at a point of time approximately 100 msec. after stimulation.
Claim 4
Dependent Claim
31 words
The method of claim 1 wherein the step of measuring the peaked responses at the predetermined elapsed time from stimulation occurs at a point of time approximately 180 msec. after stimulation.
Claim 5
Dependent Claim
36 words
The method of claim 1 wherein said visual stimuli is a pattern of parallel alternative black lines and white lines, and includes the step of rotating said pattern before the subject''s eyes for detecting astigmatic error.
Claim 6
Dependent Claim
17 words
The method of claim 1 wherein said visual stimuli is a checkerboard pattern for detecting refractive error.
Claim 7
Independent Claim
101 words
A method of objectively determining the refractive and astigmatic errors in the spatial vision of a subject including the steps of: a. placing before the subject periodically flashing visual stimuli having sharp contours; b. applying a graded series of opthalmic lenses in succession in front of the eyes of the subject; c. recording the evoked cortical responses of said subject to said stimulation for each lens condition; and d. correlating the cortical responses obtained from each of said lenses and determining which lens produces the largest cortical responses at two predetermined elapsed times after stimulation thus providing the best optometric correction.
Claim 8
Independent Claim
101 words
A method of objectively determining the refractive and astigmatic errors in the spatial vision of a subject including the steps of: a. placing before the subject periodically flashing visual stimuli having sharp contours; b. applying a graded series of opthalmic lenses in succession in front of the eyes of the subject; c. recording the evoked cortical responses of said subject to said stimulation for each lens condition; and d. correlating the cortical responses obtained from each of said lenses and determining which lens produces the largest cortical responses at two predetermined elapsed times after stimulation thus providing the best optometric correction.
Claim 9
Independent Claim
195 words
A method for objectively determining the refractive and astigmatic errors in the spatial vision of a subject including the steps of: a. placing before the subject periodically flashing stimuli having a pattern with sharp contours in a first series of stimulations; b. applying a graded series of opthalmic lenses in succession in front of the eyes of the subject; c. recording the evoked cortical responses of said subject to said stimulation for each lens condition; d. submitting the subject to said stimuli in a second series of stimulations in which all traces of the pattern have been removed; e. recording the evoked cortical responses of said subject during the second series of stimulation; f. subtracting by means of a computer the measurements of the second series from the measurements obtained by the first series to eliminate certain aspects of the total stimulus whereby the remaining cortical response measurement is directly related to the sharpness of focus of said stimuli; and g. comparing the remaining cortical responses obtained for each of said lens condition and determining which lens produces the largest cortical response at a predetermined elapsed time after stimulation thus providing the best optometric correction.
Claim 10
Independent Claim
195 words
A method for objectively determining the refractive and astigmatic errors in the spatial vision of a subject including the steps of: a. placing before the subject periodically flashing stimuli having a pattern with sharp contours in a first series of stimulations; b. applying a graded series of opthalmic lenses in succession in front of the eyes of the subject; c. recording the evoked cortical responses of said subject to said stimulation for each lens condition; d. submitting the subject to said stimuli in a second series of stimulations in which all traces of the pattern have been removed; e. recording the evoked cortical responses of said subject during the second series of stimulation; f. subtracting by means of a computer the measurements of the second series from the measurements obtained by the first series to eliminate certain aspects of the total stimulus whereby the remaining cortical response measurement is directly related to the sharpness of focus of said stimuli; and g. comparing the remaining cortical responses obtained for each of said lens condition and determining which lens produces the largest cortical response at a predetermined elapsed time after stimulation thus providing the best optometric correction.
Claim 11
Dependent Claim
135 words
Apparatus for objectively determining the refractive and astigmatic errors in the spatial vision of a subject the combination comprising: visual stimuli having a contoured pattern; means for periodically submitting the stimuli before the eyes of the subjects; means for placing in front of the subject''s eyes in succession a graded series of opthalmic lenses for varying the sharpness of focus of the images of said stimuli on a subject''s retina; electrode means adapted to be positioned at selected areas on the subject''s cranium for measuring the cortical potential responses to each stimulation; and means for measuring and comparing the amplitudes of the cortical responses obtained from each of said lenses whereby it can be determined that the lens producing the largest cortical response at a predetermined elapsed time after stimulation provides the best optometric correction.
Claim 12
Dependent Claim
135 words
Apparatus for objectively determining the refractive and astigmatic errors in the spatial vision of a subject the combination comprising: visual stimuli having a contoured pattern; means for periodically submitting the stimuli before the eyes of the subjects; means for placing in front of the subject''s eyes in succession a graded series of opthalmic lenses for varying the sharpness of focus of the images of said stimuli on a subject''s retina; electrode means adapted to be positioned at selected areas on the subject''s cranium for measuring the cortical potential responses to each stimulation; and means for measuring and comparing the amplitudes of the cortical responses obtained from each of said lenses whereby it can be determined that the lens producing the largest cortical response at a predetermined elapsed time after stimulation provides the best optometric correction.
Claim 13
Dependent Claim
12 words
The apparatus of claim 8 wherein said stimuli is a checkerboard configuration.
Claim 14
Dependent Claim
21 words
The apparatus of claim 9 wherein the elements of said checkerboard pattern subtend about 10''-15'' of arc measured from the subject.
Claim 15
Dependent Claim
36 words
The apparatus of claim 8 wherein said comparing means includes an average response type computer for summating a plurality of the cortical responses for each lens condition; and means for recording waveform outputs from said computer.
Claim 16
Dependent Claim
33 words
The apparatus of claim 11 wherein: a. the subject is positioned in a darkened, electrically shielded room; and b. a flashing lamp for periodically illuminating the stimuli to be visible by the subject.
Claim 17
Dependent Claim
30 words
The apparatus of claim 12 wherein a switch is provided as a trigger in a circuit with said lamp to initiate operation of said computer whenever the stimuli is illuminated.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-04-12 | 1974-10-12 | 1975-04-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-04-12 | 1978-10-12 | 1979-04-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-04-12 | 1982-10-12 | 1983-04-13 | $7700.00 | Window Closed / Lapsed |