Cognition and motor timing diagnosis using smooth eye pursuit analysis

• US 20060270945A1
• Filed: 10/05/2005
• Published: 11/30/2006
• Est. Priority Date: 02/11/2004
• Status: Active Grant

• Current Assignee: Sync Think, Inc.
• Original Assignee: Jamshid Ghajar
• Inventors: Ghajar, Jamshid
• Granted Patent: US 7,819,818 B2
• Time in Patent Office: Days
• US Class Current: 600/558
• CPC Class Codes: A61B 3/113 for determining or recording eye movement
• CPC Class Codes: A61B 5/162 Testing reaction times
• CPC Class Codes: A61B 5/163 by tracking eye movement, gaze, or pupil change
• CPC Class Codes: A61B 5/377 using evoked responses
• CPC Class Codes: A61B 5/486 Bio-feedback A61B5/375 takes precedence
• CPC Class Codes: G16H 50/20 for computer-aided diagnosis, e.g. based on medical expert systems
• CPC Class Codes: Y10S 128/92 Computer assisted medical diagnostics
• CPC Class Codes: Y10S 128/922 including image analysis
• CPC Class Codes: Y10S 128/923 by comparison of patient data to other data
• CPC Class Codes: Y10S 128/924 using artificial intelligence
• CPC Class Codes: Y10S 128/925 Neural network

Abstract

A system for testing a subject for cognitive impairment includes a display, one or more video cameras and a computer. The display presents to the subject multiple stimuli, including a predictable, smoothly moving object, repeatedly moving over a same path. The video cameras sense eye movements of the subject, while the subject visually follows the object on the display. The computer analyzes the subject'"'"'s eye movements to determine, for example, accuracy and variability of the subject'"'"'s visual pursuit of the display of the smoothly moving object, and determines, based on the analysis, if the subject has a cognitive impairment. The cognitive impairment may be an anticipatory timing impairment. The analysis may provide one or more metrics, such as a metric of attention, a metric of fatigability and a metric of distractibility. The system may also be configured to provide feedback signals to the user, in which case the system also functions as cognition timing and motor training system.

Claims

1. A method of testing a subject for cognitive impairment, comprising:

presenting the subject with a display of a smoothly moving object, repeatedly moving over a tracking path;

measuring the subject'"'"'s eye movements during the presenting;

analyzing the subject'"'"'s eye movements to determine accuracy and variability of the subject'"'"'s visual pursuit of the display of the smoothly moving object; and

determining, based on the analyzing, if the subject has a cognitive impairment.

2. The method of claim 1, wherein the cognitive impairment is an anticipatory timing impairment.

3. The method of claim 1, wherein the tracking path of the moving object is a circular path.

4. The method of claim 1, wherein the smoothly moving object is displayed so as to repeat its movement over the tracking path with a frequency between 0.2 and 2.0 Hz.

5. The method of claim 1, wherein the analyzing includes generating an attention metric selected from the set consisting of a variability of eye position error metric, a variability of eye velocity gain metric, an eye position error metric, a rate or number of saccades metric, a visual feedback delay metric, and a combination of two or more of said metrics.

6. The method of claim 1, wherein the analyzing includes generating a metric selected from the set consisting of a metric of fatigability and a metric of distractibility.

7. The method of claim 1, wherein measuring the subject'"'"'s eye movements is accomplished using one or more video cameras having a picture frame rate of at least 400 frames per second.

8. The method of claim 1, wherein the analyzing includes generating an index of distractibility, indicative of the subject'"'"'s susceptibility to distraction.

9. The method of claim 8, including presenting auditory distraction to the subject while presenting the subject with the display of the smoothly moving object.

10. The method of claim 1, wherein the analyzing compares values determined for the subject with predetermined criteria associated with subjects having normal anticipatory timing.

11. A method of testing a subject for cognitive impairment, comprising:

determining an index of attention with respect to a subject'"'"'s performance while visually tracking a displayed object that smoothly and repeatedly moves over a tracking path; and

generating a result, based on the index of attention, that indicates whether the subject has a cognitive impairment.

12. The method of claim 11, wherein the index of attention metric is selected from the set consisting of a variability of eye position error metric, a variability of eye velocity gain metric, an eye position error metric, a rate or number of saccades metric, a visual feedback delay metric, and a combination of two or more of said metrics.

13. A method of training a subject to improve anticipatory timing, comprising:

presenting the subject with stimuli comprising a display of a smoothly moving object, repeatedly moving over a tracking path;

determining measurements associated with the subject visually responding to the display of the smoothly moving object;

determining one or more timing values associated with the measurements;

comparing the determined one or more timing values with predefined criteria; and

generating a subject feedback signal corresponding to a result of the comparing.

14. The method of claim 13, including repeating the presenting, determining, comparing and generating operations multiple times so as to generate a sequence of subject feedback signals, thereby enabling the subject to adjust their response to the stimuli in accordance with the subject feedback signals.

15. A system for testing a subject for cognitive impairment, comprising:

a display to present to the subject stimuli comprising an image of a smoothly moving object, repeatedly moving over a tracking path;

a video sensor for sensing eye movements of the subject; and

a computer configured to

analyze the subject'"'"'s eye movements to determine at least accuracy and variability of the subject'"'"'s visual pursuit of the display of the smoothly moving object; and

determine, based on the analyzing, if the subject has a cognitive impairment.

16. The system of claim 15, wherein the cognitive impairment is an anticipatory timing impairment.

17. The system of claim 15, wherein the tracking path of the moving object is a circular path.

18. The system of claim 15, wherein the smoothly moving object is displayed so as to repeat its movement over the tracking path with a frequency between 0.2 and 2.0 Hz.

19. The system of claim 15, wherein the computer is configure to generate an attention metric selected from the set consisting of a variability of eye position error metric, a variability of eye velocity gain metric, an eye position error metric, a rate or number of saccades metric, a visual feedback delay metric, and a combination of two or more of said metrics.

20. The system of claim 15, wherein the video sensor comprises one or more video cameras having a picture frame rate of at least 400 frames per second.