Apparatus and method for measuring vestibular ocular reflex function

• US 5,942,954 A
• Filed: 08/14/1998
• Issued: 08/24/1999
• Est. Priority Date: 08/22/1997
• Status: Expired due to Fees

• Current Assignee: Massachusetts Institute of Technology
• Original Assignee: Massachusetts Institute of Technology
• Inventors: Tangorra, James, Jones, Lynette A., Hunter, Ian W., Galiana, Henrietta L.
• Primary Examiner(s): MANUEL, GEORGE C
• Application Number:
  US09/134,329
• Time in Patent Office: 375 Days
• Field of Search: 351/200, 351/205, 351/209, 435/7.21, 607/54, 600/546, 600/558
• US Class Current: 351/209
• CPC Class Codes: A61B 3/113 for determining or recording eye movement
• CPC Class Codes: A61B 5/398 Electrooculography [EOG], e.g. detecting nystagmus; Electroretinography [ERG]
• CPC Class Codes: A61B 5/4863 Measuring or inducing nystagmus

Abstract

An apparatus and method for analyzing visual and vestibular responses of a subject. One or more targets undergoing slow random motion are presented to the subject while the head of the subject is simultaneous perturbed with perturbations statistically uncorrelated with the random motion of the target. The response of the motion of the head of the subject and the motion of the subject'"'"'s eyes is measured and the visual and vestibular system response dynamics are estimated based on the measured response.

Claims

1. A method for analyzing visual and vestibular responses of a subject having a head and at least one eyeball, the method comprising:

a. displaying to the subject at least one target undergoing slow random motion;

b. perturbing the head of the subject with perturbations statistically uncorrelated with the random motion of the at least one target;

c. measuring the response of at least one of the motion of the head of the subject and the motion of the at least one eyeball of the subject; and

d. estimating visual and vestibular system response dynamics based on the measured response.

2. A method according to claim 1, wherein the step of displaying includes visually displaying a target.

3. A method according to claim 1, wherein the step of displaying includes auditorially displaying a target.

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

a. comparing the measured response of the subject with accumulated data in such a manner as to distinguish a functionally normal subject from a functionally deficient subject.

5. A method for analyzing the interaction between vergence, head processing, and conjugate eye reflexes in a subject having a head and two eyeballs, the method comprising:

a. displaying to the subject at least one target undergoing slow random motion;

b. perturbing the head of the subject with perturbations statistically uncorrelated with the random motion of the at least one target;

c. measuring the response of the motion of the head of the subject and the motion of the eyeballs of the subject; and

d. estimating visual and vestibular system coupling based on the measured response.

6. A method for classifying the qualification for a specified function of an individual having a head and at least one eyeball, the method comprising:

a. displaying to the individual at least one target undergoing slow random motion;

b. perturbing the head of the individual with perturbations statistically uncorrelated with the random motion of the at least one target;

c. measuring the response of at least one of the motion of the head of the individual and the motion of the at least one eyeball;

d. estimating visual and vestibular system response dynamics based on the measured response; and

e. comparing the measured response of the individual with predetermined ranges of acceptable responses in such a manner as to distinguish a capable candidate from a deficient candidate.

7. A method for rehabilitating a subject suffering from a vestibular deficiency, the method comprising:

a. determining the vestibular deficits of the subject;

b. displaying to the subject at least one target undergoing slow random motion;

c. perturbing the head of the subject with perturbations programmed to stimulate correction of the vestibular deficits of the subject.

8. A portable apparatus for analyzing visual and vestibular responses of a subject having a head and at least one eyeball, the apparatus comprising:

a. a perturber for applying a torque perturbation to the head of the subject;

b. a transducer for measuring the torque applied to the head of the subject;

c. a head position tracker for measuring rotational movement of the head of the subject;

d. an eye tracker for measuring the motion of the at least one eyeball of the subject; and

e. a controller for estimating visual and vestibular system response dynamics based on the measured rotational movement of the head of the subject and motion of the at least one eyeball of the subject.

9. An apparatus according to claim 8, further comprising a transducer for measuring the torque applied to the head of the subject.

10. An apparatus according to claim 8, wherein the perturber includes a water jet.

11. An apparatus according to claim 8, further including a helmet disposed upon the head of the subject for transmitting torque perturbations applied by the perturber.

12. An apparatus according to claim 11, wherein the perturber comprises a servomotor for applying a torque to the helmet with respect to a reaction ring disposed circumferentially about the helmet.

13. An apparatus according to claim 8, wherein the head position tracker is a rotational velocity sensor.

14. An apparatus according to claim 8, wherein the eye tracker is an electro-oculograph.

15. An apparatus according to claim 8, wherein the eye tracker is a corneal reflection eye tracker.

16. An apparatus according to claim 8, wherein the perturber is disposed upon a flexible band for retaining the perturber in contact with the head of the subject.

17. An apparatus according to claim 8, wherein the controller includes a memory storage containing accumulated data such that the measured response of the subject is compared with accumulated data so as to distinguish a functionally normal subject from a functionally deficient subject.

18. An apparatus according to claim 8, further including a visual target for directing the motion of the at least one eyeball of the subject.

19. An apparatus according to claim 8, further including a three-dimensional acoustic target for directing the motion of the at least one eyeball of the subject.

20. An apparatus according to claim 8, further including a headphone device for transmitting torque perturbations applied by the perturber to the head of the subject.

21. An apparatus according to claim 8, wherein the perturber includes a Lorentz force actuator for accelerating a metal ring disposed circumferentially about the helmet in such a manner as to apply torque to the head of the subject.

22. An apparatus for rehabilitating a subject suffering from a vestibular deficiency, the apparatus comprising:

a. a perturber for applying a torque perturbation to the head of the subject;

b. a transducer for measuring the torque applied to the head of the subject;

c. a head position tracker for measuring rotational movement of the head of the subject;

d. an eye tracker for measuring the motion of the at least one eyeball of the subject; and

e. a controller for driving the perturber with signals programmed to stimulate correction of the vestibular deficits of the subject.