Detecting ischemia

• US 7,024,238 B2
• Filed: 04/16/2004
• Issued: 04/04/2006
• Est. Priority Date: 04/16/2003
• Status: Active Grant

• Current Assignee: NEMCH BOX 817, New England Medical Center Hospitals, Inc.
• Original Assignee: New England Medical Center Hospitals, Inc.
• Inventors: Bergethon, Peter
• Primary Examiner(s): Nasser, Robert L.
• Application Number:
  US10/826,870
• Publication Number:
  US 20040267153A1
• Time in Patent Office: 718 Days
• Field of Search: 600/300
• US Class Current: 600/544
• CPC Class Codes: A61B 5/377 using evoked responses
• CPC Class Codes: A61B 5/4076 Diagnosing or monitoring particular conditions of the nervous system A61B5/4821, A61B5/4824 take precedence

Abstract

In one aspect, a method of detecting ischemia within the brain of a patient. The method includes assigning a first value to a first signal generated by a tissue on the right-hand side of the body and assigning a second value to a second signal generated by a tissue on the left-hand side of the body. The method also includes comparing the first value and the second value. The difference between the first value and the second value indicates that ischemia is present within the patient'"'"'s brain.

Claims

1. A method of detecting ischemia within the brain of a patient, the method comprising:

applying a first stimulus to the left-hand side of the body;

assigning a first value to a first signal generated by a tissue on the right-hand side of the body in response to the first stimulus;

applying a second stimulus to the right-hand side of the body;

assigning a second value to a second signal generated by a tissue on the left-hand side of the body in response to the second stimulus; and

comparing the first value and the second value, wherein a difference between the first value and the second value indicates that ischemia is present within the brain.

2. The method of claim 1, wherein the first stimulus or the second stimulus comprises an electrical stimulus.

3. The method of claim 1, wherein the first stimulus or the second stimulus comprises an auditory stimulus or a visual stimulus.

4. The method of claim 1, wherein the first stimulus or the second stimulus comprises a stimulus to the patient'"'"'s skin or an underlying muscle.

5. The method of claim 1, wherein the first stimulus is applied to a sensory organ on the left-hand side of the body and the first signal is generated by the right hemisphere of the brain.

6. The method of claim 5, wherein the second stimulus is applied to a sensory organ on the right-hand side of the body and the second signal is generated by the left hemisphere of the brain.

7. The method of claim 6, wherein the sensory organ is the eye or ear and the first signal or the second signal is an electrical signal.

8. The method of claim 7, wherein the first electrical signal is a first somatosensory evoked potential (SSEP) and the second signal is a second SSEP.

9. The method of claim 8, wherein the first value is based on an amplitude of the first SSEP and the second value is based on an amplitude of the second SSEP.

10. The method of claim 8, wherein the first value is based on a latency of the first SSEP and the second value is based on a latency of the second SSEP.

11. The method of claim 1, wherein the first stimulus is applied to a nerve innervating a muscle on the left-hand side of the body and the first signal is generated by the right hemisphere of the brain.

12. The method of claim 11, wherein the second stimulus is applied to a nerve innervating a muscle on the right-hand side of the body and the second signal is generated by the left hemisphere of the brain.

13. The method of claim 12, wherein the nerve is the median nerve, ulnar nerve, common peroneal nerve, or posterior tibial nerve.

14. The method of claim 12, wherein the first electrical signal is a first SSEP and the second signal is a second SSEP.

15. The method of claim 14, wherein the first value is based on an amplitude of the first SSEP and the second value is based on an amplitude of the second SSEP.

16. The method of claim 14, wherein the first value is based on the latency of the first SSEP and the second value is based on the latency of the second SSEP.

17. The method of claim 1, wherein the patient is a human patient.

18. The method of claim 1, wherein the first stimulus and the second stimulus are comparable.

19. An article comprising a machine-readable medium that stores executable instructions for detecting ischemia within the brain of a patient, the instructions causing a machine to:

apply a first stimulus to the left-hand side of the body;

assign a first value to a first signal generated by a tissue on the right-hand side of the body in response to the first stimulus;

apply a second stimulus to the right-hand side of the body;

assign a second value to a second signal generated by a tissue on the left-hand side of the body in response to the second stimulus; and

compare the first value and the second value, wherein a difference between the first value and the second value indicates that ischemia is present within the brain.

20. The article of claim 19, wherein the first stimulus or the second stimulus comprises an electrical stimulus.

21. The article of claim 19, wherein the first stimulus or the second stimulus comprises an auditory stimulus or a visual stimulus.

22. The article of claim 19, wherein the first stimulus or the second stimulus comprises a stimulus to the patient'"'"'s skin or an underlying muscle.

23. The article of claim 19, wherein the first stimulus is applied to a sensory organ on the left-hand side of the body and the first signal is generated by the right hemisphere of the brain.

24. The article of claim 23, wherein the second stimulus is applied to a sensory organ on the right-hand side of the body and the second signal is generated by the left hemisphere of the brain.

25. The article of claim 24, wherein the sensory organ is the eye or ear and the first signal or the second signal is an electrical signal.

26. The article of claim 25, wherein the first electrical signal is a first somatosensory evoked potential (SSEP) and the second signal is a second SSEP.

27. The article of claim 26, wherein the first value is based on an amplitude of the first SSEP and the second value is based on an amplitude of the second SSEP.

28. The article of claim 27, wherein the first value is based on a latency of the first SSEP and the second value is based on a latency of the second SSEP.

29. The article of claim 19, wherein the first stimulus is applied to a nerve innervating a muscle on the left-hand side of the body and the first signal is generated by the right hemisphere of the brain.

30. The article of claim 29, wherein the second stimulus is applied to a nerve innervating a muscle on the right-hand side of the body and the second signal is generated by the left hemisphere of the brain.

31. The article of claim 30, wherein the nerve is the median nerve, ulnar nerve, common peroneal nerve, or posterior tibial nerve.

32. The article of claim 30, wherein the first electrical signal is a first SSEP and the second signal is a second SSEP.

33. The article of claim 32, wherein the first value is based on an amplitude of the first SSEP and the second value is based on an amplitude of the second SSEP.

34. The article of claim 32, wherein the first value is based on the latency of the first SSEP and the second value is based on the latency of the second SSEP.

35. The article of claim 19, wherein the patient is a human patient.

36. The method of claim 19, wherein the first stimulus and the second stimulus are comparable.

37. An apparatus comprising

a memory that stores executable instructions for detecting ischemia within the brain of a patient;

and a processor that executes the executable instructions to;

apply a first stimulus to the left-hand side of the body;

assign a first value to a first signal generated by a tissue on the right-hand side of the body in response to the first stimulus;

apply a second stimulus to the right-hand side of the body;

assign a second value to a second signal generated by a tissue on the left-hand side of the body in response to the second stimulus; and

compare the first value and the second value, wherein a difference between the first value and the second value indicates that ischemia is present within the brain.

38. The apparatus of claim 37, wherein the first stimulus or the second stimulus comprises an electrical stimulus.

39. The apparatus of claim 37, wherein the first stimulus or the second stimulus comprises an auditory stimulus or a visual stimulus.

40. The apparatus of claim 37, wherein the first stimulus or the second stimulus comprises a stimulus to the patient'"'"'s skin or an underlying muscle.

41. The apparatus of claim 37, wherein the first stimulus is applied to a sensory organ on the left-hand side of the body and the first signal is generated by the right hemisphere of the brain.

42. The apparatus of claim 41, wherein the second stimulus is applied to a sensory organ on the right-hand side of the body and the second signal is generated by the left hemisphere of the brain.

43. The apparatus of claim 42, wherein the sensory organ is the eye or ear and the first signal or the second signal is an electrical signal.

44. The apparatus of claim 43, wherein the first electrical signal is a first somatosensory evoked potential (SSEP) and the second signal is a second SSEP.

45. The apparatus of claim 44, wherein the first value is based on an amplitude of the first SSEP and the second value is based on an amplitude of the second SSEP.

46. The apparatus of claim 44, wherein the first value is based on a latency of the first SSEP and the second value is based on a latency of the second SSEP.

47. The apparatus of claim 37, wherein the first stimulus is applied to a nerve innervating a muscle on the left-hand side of the body and the first signal is generated by the right hemisphere of the brain.

48. The apparatus of claim 47, wherein the second stimulus is applied to a nerve innervating a muscle on the right-hand side of the body and the second signal is generated by the left hemisphere of the brain.

49. The apparatus of claim 48, wherein the nerve is the median nerve, ulnar nerve, common peroneal nerve, or posterior tibial nerve.

50. The apparatus of claim 48, wherein the first electrical signal is a first SSEP and the second signal is a second SSEP.

51. The apparatus of claim 50, wherein the first value is based on an amplitude of the first SSEP and the second value is based on an amplitude of the second SSEP.

52. The apparatus of claim 50, wherein the first value is based on the latency of the first SSEP and the second value is based on the latency of the second SSEP.

53. The apparatus of claim 37, wherein the patient is a human patient.

54. The method of claim 37, wherein the first stimulus and the second stimulus are comparable.