Functional near infrared spectroscopy based brain computer interface
Described herein are fNIR-based brain computer interfaces. Training of individuals to intentionally control neural activity in specific cortical areas, thereby up-regulating and down-regulating oxygenation levels in specific locations in the brain is also provided herein. Further, continuous and/or binary control over computing environments using fNIR brain computer interfaces. Further still, a scale for brain interface index for oxygenation of a portion of the brain is provided herein.
1. A system, comprising:
one or more near infrared sources configured to emit infrared radiation onto a portion of a cortical region of a person;
one or more detectors configured to receive infrared radiation indicative of a level of oxygenated hemoglobin and a level of deoxygenated hemoglobin in the portion of the cortical region;
the system further comprising a feedback source configured to provide feedback to the person based on one or more of the level of oxygenated hemoglobin and the level of deoxygenated hemoglobin in the cortical region; and
the system comprising a processor configured to correlate a change in the one or more of the level of oxygenated hemoglobin and the level of deoxygenated hemoglobin with a change in the feedback,
the feedback being changed when a change in the one or more of the level of oxygenated hemoglobin and the level of deoxygenated hemoglobin is above a threshold value.
2. The system of claim 1 , wherein the feedback is visual feedback.
3. The system of claim 1 , wherein the feedback is a real time representation of deoxygenated hemoglobin in the cortical region.
4. The system of claim 1 , wherein the feedback source comprises a display configured to provide a prompt to the person for initiating an up-regulation or down-regulation of deoxygenated hemoglobin in the cortical region.
5. The system of claim 1 , wherein the processor is configured to determine that the one or more of the level of deoxygenated hemoglobin and the level of oxygenated hemoglobin in the cortical region indicates a level of concentration by the person.
6. The system of claim 1 wherein the processor is configured to determine that a change in one or more of the level of oxygenated hemoglobin and the level of deoxygenated hemoglobin indicates the person's intent to alter the feedback.
7. The system of claim 1 , wherein the processor is configured to correlate the one or more of the level of oxygenated hemoglobin and the level of deoxygenated hemoglobin with the person's control of a binary, step, or continuous computing function.
8. The system of claim 7 , the processor being further configured to correlate the one or more of the level of oxygenated hemoglobin and deoxygenated hemoglobin with the person's control of a binary or step computing function.
9. The system of claim 1 , wherein the cortical region comprises the prefrontal cortex.
10. The system of claim 1 , wherein the change in the feedback is based on a conversion parameter that controls a sensitivity in feedback to the change in oxygenated or deoxygenated hemoglobin levels.
11. A system, comprising:
one or more near infrared sources configured to emit infrared radiation onto a portion of a cortex of a person;
one or more detectors configured to receive infrared radiation indicative of a level of oxygenated hemoglobin and a level of deoxygenated hemoglobin of the portion of the cortex; and
the system comprising a feedback source configured to provide feedback to the person based on one or more of the level of oxygenated hemoglobin and the level of deoxygenated hemoglobin in the portion of the cortex; and
the system comprising a processor configured to correlate the one or more of the level of oxygenated hemoglobin and the level of deoxygenated hemoglobin in the portion of the cortex with a computing function, the feedback being changed when a change in the one or more of the level of oxygenated hemoglobin and the level of deoxygenated hemoglobin is above a threshold value.
12. The system of claim 11 , wherein the feedback is visual feedback.
13. The system of claim 11 , wherein the feedback is a real time representation of deoxygenated hemoglobin the in the portion of the cortex.
14. The system of claim 11 , wherein the display is further configured to provide a prompt to the person for initiating an up-regulation or down-regulation of deoxygenated hemoglobin in the portion of the cortex.
15. The system of claim 11 , wherein the processor is configured to correlate one or more of the level of oxygenated hemoglobin and the level of deoxygenated hemoglobin in the portion of the cortex to a level of concentration by the person.
16. The system of claim 11 , wherein the portion of the cortex is a portion of the prefrontal cortex.
17. The system of claim 11 , wherein the computing function is a binary or step computing function.
18. The system of claim 11 , wherein the computer function is a continuous computing function.
19. The system of claim 11 , wherein the first portion of the cortex comprises the prefrontal cortex.
20. The system of claim 11 , wherein a change in the feedback is based on a conversion parameter that controls a sensitivity in the feedback to the change in oxygenated or deoxygenated hemoglobin levels.
21. A method for training a person to control a computer with a first portion of their cortical region, the method comprising:
emitting near infrared radiation from one or more emitters onto a portion of the cortical region;
receiving at a detector, first radiation from the portion of the cortical region, said first radiation including information indicative of one or more of a first level of oxygenated hemoglobin and a first level of deoxygenated hemoglobin of the portion of the cortical region;
providing to the person first feedback based on the one or more of the first level of oxygenated hemoglobin and the first level of deoxygenated hemoglobin of the portion of the cortical region;
receiving at a detector, second radiation from the portion of the cortical region, said second radiation including information indicative of one or more of a second level of oxygenated hemoglobin and a second level of deoxygenated hemoglobin of the portion of the cortical region; and
providing to the person second feedback based on the one or more of the second level of oxygenated hemoglobin and the second level of deoxygenated hemoglobin of the portion of the cortical region,
the second feedback being provided when a change between the one or more of the first and second levels of oxygenated hemoglobin and the first and second levels of deoxygenated hemoglobin is above a threshold value.
22. The method of claim 21 , wherein first feedback and the second feedback are visual feedback.
23. The method of claim 22 , further comprising iteratively adjusting at least one of the first and second feedback based on a change between the one or more of the first and second levels of oxygenated hemoglobin and the first and second levels of deoxygenated hemoglobin.
24. The method of claim 21 , wherein providing to the person first feedback further comprises simultaneously determining a brain interface index of oxygenation levels, said brain interface index of oxygenation levels configured to provide a reference.
25. The method of claim 24 , wherein the brain interface index comprises a predetermined dynamically adjusted scaling constant.
26. The method of claim 21 , further comprising providing the person with binary or step control over a computing function, the binary or step control being based one or more of a level of oxygenated hemoglobin and a level of deoxygenated hemoglobin in the portion of the cortical region.
27. The method of claim 21 , further comprising providing the person with continuous control over a computing function, the continuous control being based on one or more of a level of oxygenated hemoglobin and a level of deoxygenated hemoglobin in the portion of the cortical region.
28. The method of claim 21 , wherein the portion of the cortical region comprises the prefrontal cortex.
29. The method of claim 21 , wherein the second feedback is proportional to the change in oxygenated or deoxygenated hemoglobin levels.
30. The method of claim 29 , wherein the second feedback is based on a conversion parameter that controls a sensitivity in the feedback to the change in oxygenated or deoxygenated hemoglobin levels.
31. The method of claim 30 , further comprising changing the conversion parameter after providing the first or second feedback, changing the conversion parameter based on a characteristic of the person, or any combination thereof.
32. A method for determining the activation level of a portion of the cortex of a person, the method comprising:
emitting at least two wavelengths of near infrared radiation from one or more emitters onto the portion of the cortex;
receiving at a detector, radiation from the portion of the cortex, said radiation including information indicative of a level of oxygenated hemoglobin and indicative of a level of deoxygenated hemoglobin of the portion of the cortex;
determining the levels of oxygenated hemoglobin and deoxygenated hemoglobin, wherein the level of deoxygenated hemoglobin is determined independently from the level of oxygenated hemoglobin;
correlating one or both of the levels of oxygenated hemoglobin and deoxygenated hemoglobin to an activation level of the cortex; and
providing a feedback to the person based on the activation level of the cortex.
33. The method of claim 32 , wherein the portion of the cortex comprises the prefrontal cortex.