Spectrophotometer for tissue examination

• US 6,549,795 B1
• Filed: 07/14/1998
• Issued: 04/15/2003
• Est. Priority Date: 05/16/1991
• Status: Expired due to Term

• Current Assignee: Non-Invasive Technology Incorporated
• Original Assignee: Non-Invasive Technology Incorporated
• Inventors: Chance, Britton
• Primary Examiner(s): WINAKUR, ERIC FRANK
• Application Number:
  US09/115,329
• Time in Patent Office: 1,736 Days
• Field of Search: 600/310, 600/322, 600/323, 600/324, 600/340
• US Class Current: 600/340
• CPC Class Codes: A61B 2562/0242 for varying or adjusting the optical path length in the tissue
• CPC Class Codes: A61B 5/14552 Details of sensors specially adapted therefor
• CPC Class Codes: A61B 5/6824 Arm or wrist
• CPC Class Codes: A61B 5/7257 using Fourier transforms

Abstract

A method and apparatus for transcranial examination of brain activity. Electromagnetic radiation of a selected wavelength is introduced into the brain from an input port located on an exterior of the subject'"'"'s head. Radiation that has migrated through the subject'"'"'s head is detected at a detection port to generate detected signals. While introducing and detecting the electromagnetic radiation, stimulation of brain activity is induced. The detected radiation signals are processed, and the processed signals are analyzed to determine a characteristic of the brain activity by correlating the processed signals with the stimulation.

Claims

1. A method of transcranial examination of brain activity by measuring changes in electromagnetic radiation scattered and absorbed in a migration path in the brain comprising

(a) introducing electromagnetic radiation of a selected wavelength into the brain at an input port placed at a selected location on the exterior of the head,

(b) detecting, at a detection port placed at a selected location on the exterior of the head, radiation of said selected wavelength that has migrated in the brain,

(c) causing stimulation of a brain activity while introducing said radiation at said input port and while detecting radiation of said detection port,

(d) processing signals of said detected radiation that has migrated in the brain to create processed data, and

(e) determining a characteristic of said brain activity by correlating said processed data with said caused stimulation of said brain activity.

2. The method of claim 1 wherein said steps of introducing said radiation into the brain and detecting said radiation that has migrated in the brain, while causing stimulation of said brain activity, are repeated at different locations on the exterior of the head, and said step of processing said detected radiation to create processed data is correspondingly repeated.

3. The method of claim 1 or 2 wherein said input port and said output port are located on one of the following:

the frontal bone, parietal bone, temporal bone or occipital bone;

said input port and said output port being separated by a predetermined distance in order to localize said migration of said radiation to a selected region of the brain.

4. The method of claim 3 wherein said predetermined distance is 4 centimeters.

5. The method of claim 1 further comprising

(a) introducing electromagnetic radiation of said selected wavelength into the brain at a second input port placed at a second selected location on the exterior of the head,

(b) detecting, at a second detection port placed at a selected location on the exterior of the head, radiation of said selected wavelength that has migrated in the brain from said second input port to said second detection port,

(c) processing signals of said detected radiation that has migrated in the brain from said second input port to said second detection port to create second processed data, and

(d) determining a characteristic of said brain activity by correlating both first mentioned and said second processed data with said caused stimulation of said brain activity.

6. The method of claim 5 wherein said radiation is simultaneously introduced at said first and second input ports and detected at said first and second detection ports.

7. The method of claim 5 wherein said radiation is first introduced at said first input port and detected at said first detection port, and subsequently said radiation is introduced at said second input port and detected at said second detection port.

9. The method of claim 8 or 5 wherein said first input port and said first output port are located on one parietal bone, separated by a predetermined distance, in order to localize migration of said radiation in a selected region of the respective hemisphere of the brain, and said second input port and said second output port are located on the other parietal bone, separated by a predetermined distance, in order to localize migration of said radiation in a selected region of the other hemisphere of the brain.

10. The method of claim 9 wherein said processing comprises comparing electromagnetic radiation detected at said first and second detection ports to create processed data representing a differential signal.

11. The method of claim 8 or 5 wherein said first input port and said first output port are located on one temporal bone, separated by a predetermined distance, in order to localize migration of said radiation in a selected region of the respective hemisphere of the brain, and said second input port and said second output port are located on the other temporal bone, separated by a predetermined distance, in order to localize migration of said radiation in a selected region of the other hemisphere of the brain.

12. The method of claim 11 wherein said processing comprises comparing electromagnetic radiation detected at said first and second detection ports to create processed data representing a differential signal.

13. The method of claim 1, 8 or 5 wherein said processing of said detected radiation comprises Fourier transformation.

14. The method of claim 1, 8 or 5 wherein said stimulation is visual stimulation.

15. The method of claim 1, 8 or 5 wherein said stimulation is acoustic stimulation.

16. The method of claim 1, 8 or 5 wherein said stimulation is sensorimotor stimulation.

17. The method of claim 1, 8 or 5 further comprising examining cognitive function of a selected region of the brain based on correlation between said processed data and said caused stimulation of said brain activity.

18. The method of claim 1, 8 or 5 further comprising examining pathological/pathophysiological state of a tissue of a selected region of the brain based on correlation between said processed data and said caused stimulation of said brain activity.

8. A method of transcranial examination of brain activity by measuring changes in electromagnetic radiation scattered and absorbed in a migration path in the brain comprising

(a) introducing electromagnetic radiation of a selected wavelength into the brain simultaneously at a first input port and at a second input port, said first input port and said second input port being placed at a first selected location and a second selected location on the exterior of the head, respectively,

(b) detecting simultaneously, at a first detection port placed at a selected location on the exterior of the head, radiation that has migrated in the brain from said first input port to said first detection port and, at a second detection port placed at second selected location on the exterior of the head, radiation that has migrated in the brain from said second input port to said second detection port,

(c) causing stimulation of a brain activity while introducing said radiation at said first and second input ports and while detecting radiation at said first and second detection ports,

(d) processing signals of said detected radiation that has migrated in the brain to create processed data, and

(e) determining a characteristic of said brain activity by correlating said processed data to said caused stimulation of said brain activity.

19. A cognition spectrophotometer system for transcranial examination of brain activity by measuring changes in electromagnetic radiation scattered and absorbed in a migration path in the brain comprising

(a) a light source adapted to introduce electromagnetic radiation of a selected wavelength into the brain at an input port placed at a selected location on the exterior of the head,

(b) a detector adapted to detect, at a detection port placed at a selected location on the exterior of the head, radiation of said selected wavelength that has migrated in the brain,

(c) stimulation means adapted to cause stimulation of a brain activity while introducing said selected wavelength and while detecting radiation at said detection port,

(d) processing means adapted to process signals of said detected radiation that has migrated in the brain to create processed data, and

(e) evaluation means adapted to determine a characteristic of said brain activity by correlating said processed data with said caused stimulation of said brain activity.

20. The system of claim 19 wherein said processing means adapted to process detected radiation that has migrated in the brain in said migration path between said input port and said output port being separated by a predetermined distance and being located at different locations on the exterior of the head.

21. The system of claim 19 or 20 wherein said input port and said output port are located on one of the following:

the frontal bone, parietal bone, temporal bone or occipital bone;

said input port and said output port being separated by a predetermined distance in order to localize said migration of said radiation to a selected region of the brain.

22. The system of claim 21 wherein said predetermined distance is 4 centimeters.

23. The system of claim 19 further comprising

(a) a second light source adapted to introduce electromagnetic radiation of said selected wavelength into the brain at a second input port placed at a second selected location on the exterior of the head,

(b) a second detector adapted to detect, at a second detection port placed at a selected location on the exterior of the head, radiation of said selected wavelength that has migrated along said migration path in the brain from said second input port to said second detection port, and

(c) processing means adapted to process signals of said detected radiation that has migrated in the brain from said second input port to said second detection port to create second processed data,

wherein said evaluation means determine said characteristic of said brain activity by correlating both first mentioned and said second processed data with said caused stimulation of the brain.

24. The system of claim 23 adapted to introduce simultaneously said radiation at said first and second input ports and detect at said first and second detection ports.

25. The system of claim 23 adapted to introduce said radiation first at said first input port and detected at said first detection port, and subsequently introduce said radiation at said second input port and detected at said second detection port.

27. The system of claim 26 or 23 wherein said first input port and said first output port being located on one parietal bone, separated by a predetermined distance, in order to localize migration of said radiation in a selected region of the respective hemisphere of the brain, and said second input port and said second output port being located on the other parietal bone, separated by a predetermined distance, in order to localize migration of said radiation in a selected region of the other hemisphere of the brain.

28. The system of claim 27 wherein said processing means further adapted to compare electromagnetic radiation detected at said first and second detection ports to create processed data representing a differential signal.

29. The system of claim 26 or 23 wherein said first input port and said first output port are located on one temporal bone, separated by a predetermined distance, in order to localize migration of said radiation in a selected region of the respective hemisphere of the brain, and said second input port and said second output port are located on the other temporal bone, separated by a predetermined distance, in order to localize migration of said radiation in a selected region of the other hemisphere of the brain.

30. The system of claim 29 wherein said processing means further adapted to compare electromagnetic radiation detected at said first and second detection ports to create processed data representing a differential signal.

31. The system of claim 19, 26 or 23 wherein said processing of said detected radiation comprises Fourier transformation.

32. The system of claim 19, 26 or 23 wherein said stimulation means adapted to cause visual stimulation.

33. The system of claim 19, 26 or 23 wherein said stimulation means adapted to cause acoustic stimulation.

34. The system of claim 19, 26 or 23 wherein said stimulation means adapted to cause sensorimotor stimulation.

35. The system of claim 19, 26 or 23 wherein said evaluation means further adapted to examine cognitive function of a selected region of the brain based on correlation between said processed data and said caused stimulation of said brain activity.

36. The system of claim 19, 26 or 23 wherein said evaluation means further adapted to examine tissue of a selected region of the brain based on correlation between said processed data and said caused stimulation of said brain activity.

37. The cognition spectrophotometer system of claim 19 or 26 wherein said evaluation means is arranged to evaluate a pathological/pathophysiological state of a tissue of a selected region of the brain based on correlation between said processed data and said caused stimulation of said brain activity.

26. A cognition spectrophotometer system for transcranial examination of brain activity by measuring changes in electromagnetic radiation scattered and absorbed in a migration path in the brain comprising

(a) a first light source and a second light source adapted to introduce electromagnetic radiation of a selected wavelength into the brain simultaneously at a first input port and at a second input port, said first input port and said second input port being placed at a first selected location and a second selected location on the exterior of the head, respectively,

(b) a first detector and a second detector adapted to detect simultaneously, at a first detection port placed at a selected location on the exterior of the head, radiation that has migrated in the brain from said first input port to said first detection port and, at a second detection port placed at second selected location on the exterior of the head, radiation that has migrated in the brain from said second input port to said second detection port,

(c) stimulation means adapted to cause stimulation of a brain activity while introducing said radiation at said first and second input ports and while detecting radiation at said first and second detection ports,

(d) processing means adapted to process signals of said detected radiation that has migrated in the brain to create processed data, and

(e) evaluation means adapted to determine a characteristic of said brian activity by correlating said processed data to said caused stimulation of said brain activity.