Alleviating motion, simulator, and virtual environmental sickness by presenting visual scene components matched to inner ear vestibular sensations

• US 6,497,649 B2
• Filed: 01/21/2001
• Issued: 12/24/2002
• Est. Priority Date: 01/21/2001
• Status: Expired due to Fees

• Current Assignee: Washington University In St Louis
• Original Assignee: University of Washington
• Inventors: Prothero, Jerrold D., Furness, Thomas A., Parker, Donald E., Duh, Been-Lirn Henry, Seibel, Eric J.
• Primary Examiner(s): Walberg, Teresa
• Assistant Examiner(s): ROBINSON, DANIEL LEON
• Application Number:
  US09/766,144
• Publication Number:
  US 20020099257A1
• Time in Patent Office: 702 Days
• Field of Search: 600/27, 600/28, 702/150, 702/153, 702/154, 702/173, 702/175, 702/176
• US Class Current: 600/27
• CPC Class Codes: A61M 2021/005 images, e.g. video
• CPC Class Codes: A61M 21/00 Other devices or methods to cause a change in the state of consciousness; Devices for producing or ending sleep by mechanical, optical, or acoustical means, e.g. for hypnosis
• CPC Class Codes: G02B 2027/0178 Eyeglass type eyeglass details G02C
• CPC Class Codes: G02B 27/0093 with means for monitoring data relating to the user, e.g. head-tracking, eye-tracking
• CPC Class Codes: G02B 27/017 Head mounted
• CPC Class Codes: G06F 3/011 Arrangements for interaction with the human body, e.g. for user immersion in virtual reality blind teaching G09B21/00

Abstract

Display of an independent visual background provides a visual reference corresponding to the perceptions of a person'"'"'s vestibular system, thereby substantially reducing or eliminating motion sickness that otherwise occur due to a mismatch between the visual perception of motion or non-motion and the sensations of the vestibular system. If the person is wearing a head-mounted display (HMD), is in motion, or is in a moving environment, a motion tracking system or other motion sensors are employed to produce signals indicative of the motion of the environment and/or of the person. The signals produced are then processed using a vestibular model, producing a modified signal corresponding to the perception of motion by the person'"'"'s vestibular system. Using this modified signal, the independent visual background is displayed to the user, providing a visual reference that corresponds to the perception of the vestibular system. If the person is in a fixed environment and watching a moveable or moving display, the IVB can either be included on the image or in a peripheral area around the display. The perceptibility of the IVB can be adjusted by the observer to minimize its distracting impact on a visual task, while ensuring that it is sufficiently perceptible to avoid motion sickness.

Claims

1. A method for preventing a person from experiencing motion sickness, comprising the steps of:

(a) sensing a motion experienced by the person;

(b) producing a signal indicative of said motion;

(c) processing the signal so as to produce a modified signal that is compensated to correspond to a perception of the motion by the vestibular system of the person; and

(d) using the modified signal, displaying an independent visual background that includes visual cues matched to the perception of the motion by the vestibular system.

2. The method of claim 1, wherein the step of processing comprises the step of employing a semicircular canal model to modify the signal.

3. The method of claim 1, wherein the step of processing comprises the step of employing an otolith model to modify the signal.

4. The method of claim 1, wherein the step of processing includes the step of compensating the signal for individual characteristics of the vestibular system of the person that affect the perception of motion.

5. The method of claim 1, wherein the step of displaying comprises the step of projecting the independent visual background onto a surface at least partially enclosing the person.

6. The method of claim 1, wherein the step of displaying the independent visual background comprises the step of displaying a grid of lines comprising the visual cues that match the perception of the motion by the vestibular system, said grid of lines including a first set of lines and a second set of lines, said first set of lines being generally orthogonal to said second set of lines.

7. The method of claim 1, wherein the step of displaying the independent visual background comprises the steps of:

(a) displaying a plurality of lines comprising the visual cues; and

(b) orienting the plurality of lines to match the perception of the motion by the vestibular system of the person.

8. The method of claim 1, wherein the person is engaged in an activity that involves a visual task, further comprising the step of displaying the independent visual background so as to limit a distracting affect of the independent visual background on the person.

9. The method of claim 8, wherein the person is enabled to control at least one of:

(a) one of an absolute and a relative luminance of the independent visual background on the display;

(b) a position at which the independent visual background appears relative to a position at which the visual task appears;

(c) a timing with which the display of the independent visual background occurs, including at least one of;

(i) a periodic time interval during which the independent visual background is repetitively displayed;

(ii) an interval between successive periodic displays of the independent visual background;

(iii) a rate at which the independent visual background is periodically displayed; and

(iv) a duration of successive displays of the independent visual background;

(d) one of a relative position, an extent, and a size at which the independent visual background is visually displayed;

(e) one of a focus and a depth position of a focal point of the independent visual background;

(f) a color of the independent visual background that is displayed; and

(g) a color contrast of the independent visual background.

10. The method of claim 8, wherein the visual task comprises the step of viewing an image in which substantial motion is portrayed, further comprising the step of displaying the independent visual background so as to avoid obscuring the image.

11. The method of claim 1, wherein the step of displaying comprises the step of moving the visual cues about in a manner consistent with the perception of the motion by the vestibular system of the person.

12. The method of claim 1, wherein the step of sensing motion comprises the step of sensing at least one of a linear position, an angular position, a linear velocity, an angular velocity, a linear acceleration, and an angular acceleration.

13. The method of claim 1, wherein the step of processing includes the step of modifying the signal as a function of a first time constant and a second time constant, said second time constant being substantially longer in duration than the first time constant.

14. The method of claim 1, wherein the step of sensing comprises the step of sensing both an angular and linear motion, and wherein the step of processing includes the step of modifying the signal to resolve an otolith ambiguity, wherein if both linear and angular motions are sensed, the independent visual background is rotated, and if the only linear motion is sensed, but not angular motion, the independent visual background is moved to indicate a translation of the person.

15. The method of claim 1, wherein the step of displaying includes the step of displaying the independent visual background so that it is visible to a plurality of people who are subject to a substantially common motion.

16. A system for preventing a person from experiencing motion sickness due to a difference between a visual sensory perception and a vestibular system perception of motion, comprising:

(a) a memory in which a plurality of machine instructions are stored;

(b) a display;

(c) at least one motion sensor that produces an output signal indicative of motion; and

(d) a processor coupled to the memory, the display, and said at least one motion sensor, said processor executing the plurality of machine instructions, causing the processor to;

(i) process the signal, producing a modified signal that is compensated to correspond to a perception of the motion by the vestibular system of the person; and

(ii) using the modified signal, display an independent visual background that includes visual cues matched to the perception of the motion by the vestibular system.

17. The system of claim 16, wherein the plurality of machine instructions further cause the processor to implement a semicircular canal model to modify the signal.

18. The system of claim 16, wherein the plurality of machine instructions further cause the processor to implement an otolith model to modify the signal.

19. The system of claim 16, wherein the plurality of machine instructions further cause the processor to compensate the signal for any affects of aging of the person.

20. The system of claim 16, wherein the display comprises a projector that projects the visual cues comprising the independent visual background onto a surface at least partially surrounding the person.

21. The system of claim 16, wherein the display comprises a projector that projects the visual cues comprising the independent visual background onto a surface worn by the person.

22. The system of claim 16, wherein the display is adapted to mount on a head of a person and to project the visual cues onto a retina of the person.

23. The system of claim 16, wherein the visual cues of the independent visual background comprise a grid of lines that are oriented to match the perception of the motion by the vestibular system, said grid of lines including a first set of lines and a second set of lines, said first set of lines being generally orthogonal to said second set of lines.

24. The system of claim 16, wherein the visual cues of the independent visual background comprise a plurality of lines that are oriented to match the perception of the motion by the vestibular system.

25. The system of claim 16, wherein the person is engaged in an activity that involves a visual task, said machine instructions further causing the processor to display the independent visual background with the display so as to reduce a distracting affect of the independent visual background on the person.

26. The system of claim 16, further comprising a control that is coupled to one of the processor and the display, said control enabling a person to control an extent to which the visual cues of the independent visual background are visually perceptible on the display.

27. The system of claim 25, wherein the control varies at least one of:

(a) a luminance of the independent visual background on the display;

(b) a position at which the independent visual background appears relative to a position at which the visual task appears;

(c) a timing with which the display of the independent visual background occurs, including at least one of;

(i) a periodic time interval during which the independent visual background is repetitively displayed;

(ii) an interval between successive periodic displays of the independent visual background;

(iii) a rate at which the independent visual background is periodically displayed; and

(iv) a duration of successive displays of the independent visual background;

(d) a relative position at which the independent visual background is visually displayed;

(e) one of a focus and a depth focal point of the independent visual background in a visually perceptible space of a person;

(f) a color of the independent visual background that is displayed; and

(g) a color contrast of the independent visual background.

28. The system of claim 26, wherein the visual task pertains to viewing an image in which substantial motion is portrayed, said machine instructions further causing the processor to provide the independent visual background on the display in a manner that does not obscure the image.

29. The system of claim 16, wherein the machine instructions further cause the process to move the visual cues consistent with the perception of the motion by the vestibular system of the person.

30. The system of claim 16, wherein said at least one sensor comprises at least one of:

(a) a linear position sensor;

(b) an angular position sensor;

(c) a linear velocity sensor;

(d) an angular velocity sensor;

(e) a linear acceleration sensor; and

(f) an angular acceleration sensor.

31. The system of claim 16, wherein the machine instructions further cause the processor to modify the signal as a function of a first time constant and a second time constant, said second time constant being substantially longer in duration than the first time constant.

32. A method for reducing an adverse physiological reaction caused by differences in a visually perceived motion and a lack of motion as sensed by the internal vestibular system of a person, comprising the steps of:

(a) providing a fixed independent visual background comprising visual cues substantially corresponding to and consistent with the lack of motion sensed by the internal vestibular system of the person; and

(b) displaying the fixed independent visual background relative to an image depicting substantial motion that is being viewed by the person, without obscuring the image, said visual cues, which are consistent with the lack of motion perceived by the internal vestibular system of the person, substantially reducing an adverse physiological reaction that would be experienced by the person if the independent visual background were not displayed.

33. The method of claim 32, further comprising the step of enabling a person to control an extent to which the visual cues comprising the independent visual background are perceptible relative to the image, in order to enable the person to set the extent sufficiently to substantially control the adverse physiological reaction.

34. The method of claim 32, wherein the step of displaying comprises the step of displaying visual cues, said visual cues comprising a first set of lines and a second set of lines, said second set of lines being substantially orthogonal to the first set of lines.

35. The method of claim 32, wherein the step of displaying comprises the step of displaying visual cues, said visual cues comprising at least one of:

(a) a plurality of substantially parallel lines; and

(b) a plurality of lines corresponding to at least a portion of a spherical surface.

36. The method of claim 32, wherein the step of displaying comprises the step of displaying line segments around a periphery of the image.

37. The method of claim 32, wherein the step of displaying comprises the step of displaying visual cues that overlie the image, said visual cues being sufficiently diffuse so as not to obscure the image.

38. The method of claim 32, wherein the step of displaying comprises the step of displaying visual cues that overlie the image, but are at a different focal point within a visually perceptible space of the person, so as not to obscure the image.

39. The method of claim 32, further comprising the step of displaying the visual cues comprising the independent visual background as a subliminal image that is not consciously perceptible.