Diagnosing and training the gaze stabilization system

• US 7,500,752 B2
• Filed: 02/12/2007
• Issued: 03/10/2009
• Est. Priority Date: 04/28/2004
• Status: Active Grant

• Current Assignee: Natus Medical Incorporated
• Original Assignee: Natus Medical Incorporated
• Inventors: Nashner, Lewis M.
• Primary Examiner(s): Sugarman; Scott J
• Assistant Examiner(s): PINKNEY, DAWAYNE
• Application Number:
  US11/673,686
• Publication Number:
  US 20070121066A1
• Time in Patent Office: 757 Days
• Field of Search: 351/200, 351/203, 351209-211, 351222-224, 351/237
• US Class Current: 351/210
• CPC Class Codes: A61B 3/0091 Fixation targets for viewing direction
• CPC Class Codes: A61B 3/028 for testing visual acuity; for determination of refraction, e.g. phoropters
• CPC Class Codes: A61B 3/032 Devices for presenting test symbols or characters, e.g. test chart projectors A61B3/036 takes precedence
• CPC Class Codes: A61B 3/113 for determining or recording eye movement
• CPC Class Codes: A61B 5/11 Measuring movement of the entire body or parts thereof, e.g. head or hand tremor, mobility of a limb for measuring pulse A61B5/02 ;A61B5/1038 takes precedence; motion detection to correct for motion artifacts in physiological signals A61B5/721

Abstract

A method for diagnosing impairments of a subject'"'"'s gaze stabilization system is provided. The method includes measuring the subject'"'"'s static visual acuity to obtain an assessment, setting at least one test parameter based on the assessment, measuring the subject'"'"'s dynamic visual acuity using the test parameters to obtain a first dynamic measurement and a second dynamic measurement, and determining an impairment of the subject'"'"'s gaze stabilization system using the assessment and the first and second dynamic measurements.

Claims

1. A method for training a subject'"'"'s gaze stabilization system, the method comprising:

measuring the subject'"'"'s static visual acuity to obtain an assessment;

displaying a display object to the subject, such that displaying includes displaying a preliminary form of the display object, displaying a test form of the display object, and redisplaying the preliminary form of the display object, the display object having at least one parameter based on the assessment;

having the subject maintain gaze on the display object when the subject and the display object are moving relative to one another; and

having the subject identify the test form of the display object.

2. A method according to claim 1, wherein having the subject maintain gaze on the display object occurs when a subject'"'"'s head is fixed and the display object is continuously moving, when the subject'"'"'s head is fixed and the display object is discontinuously moving, when the subject'"'"'s head is fixed and the display object is continuously moving and is displayed in a patterned large field background, when the subject'"'"'s head is moving and the display object is fixed, when a subject'"'"'s head is moving and a display object is continuously moving, when a subject'"'"'s head is moving and a display object is discontinuously moving, when the subject'"'"'s head is moving and the display object is continuously moving and is displayed in a patterned large field background, or any combination thereof.

3. A method according to claim 1, further comprising:

moving the display object according to a protocol.

4. A method according to claim 3, further comprising:

having the subject move according to a second protocol.

5. A method according to claim 1, further comprising:

having the subject move according to a protocol.

6. A method according to claim 1, wherein the assessment includes a minimum interval for the subject to correctly identify a visual object and displaying the test form includes displaying the test form for a display interval that is greater than or equal to the minimum interval.

7. A method according to claim 1, further comprising:

determining a first maximum velocity of a visual object that the subject correctly perceives using the subject'"'"'s smooth pursuit system, wherein displaying a display object includes moving the display object at a velocity equal to or less than the first maximum velocity.

8. A method according to claim 7, wherein displaying a display object further includes moving the display object at a velocity equal to or greater than the first maximum velocity.

9. A method according to claim 7, further comprising:

determining a second maximum velocity of the visual object that the subject correctly perceives using the subject'"'"'s optokinetic system.

10. A method according to claim 1, wherein the assessment includes a minimum size of a visual object that the subject correctly identifies and displaying a display object includes displaying the display object at a display size that is greater than or equal to the minimum size.

11. A method according to claim 1, further comprising:

having the subject perform at least one free standing balance task while maintaining gaze on the display object.

12. A method according to claim 11, wherein having the subject perform at least one free standing balance task includes having the subject stand on at least one surface which moves in relation to a display of the display object.

13. A method according to claim 12, wherein the surface is a force plate, a treadmill, or a combination thereof.

14. A method according to claim 11, wherein having the subject perform at least one free standing balance task includes surrounding the subject with a visual surround.

15. A method according to claim 1, further comprising:

determining a quantity related to proficiency of the subject'"'"'s gaze performance at selected times based on the subject identifying the test form.

16. A method according to claim 15 further comprising displaying the one or more quantities to the subject.

17. A method according to claim 16 wherein determining a quantity related to proficiency of the subject'"'"'s gaze performance includes the subject'"'"'s gaze performance related to the subject'"'"'s vestibule-ocular reflex system, the subject'"'"'s smooth pursuit eye movement system, the subject'"'"'s optokinetic eye movement system, the subject'"'"'s saccadic movement system, the subject'"'"'s vergence eye movement system, or any combination thereof.

18. A method according to claim 11, wherein having the subject perform at least one free standing balance task includes having the subject stand on at least one surface which moves according to a protocol.

19. A method according to claim 1 further comprising:

having the subject move one or more body parts according to a protocol while the subject is placed on a support surface that is moving according to a second protocol.

20. A method according to claim 1, further comprising having the subject identify a specific characteristic that distinguishes the test form from the preliminary form.

21. A method according to claim 3, wherein moving the display object according to a protocol further comprises positioning the display object in different orientations.

22. A method according to claim 21 further comprising having the subject identify the orientation of the test form.

23. A method according to claim 1, wherein the display object is displayed such that an individual eye movement control system is used, wherein the individual eye movement control system is at least one of a vestibule-ocular reflex system, a smooth pursuit eye movement system, a saccadic movement system, an optokinetic movement system, and a vergence eye movement system.

24. A method according to claim 1 wherein having the subject maintain gaze on the display object includes having the subject maintain gaze on the display object during a change in the display object from the preliminary form to the test form and then back to the preliminary form.