Method and apparatus for assessing susceptibility to stroke

• US 6,280,393 B1
• Filed: 12/02/1999
• Issued: 08/28/2001
• Est. Priority Date: 12/02/1999
• Status: Expired due to Fees

• Current Assignee: Regents of the University of California (University of California)
• Original Assignee: Thuris Corp. (Protein Polymer Technologies, Inc.)
• Inventors: Lynch, Gary, Granger, Richard
• Primary Examiner(s): Nasser, Robert L.
• Application Number:
  US09/452,202
• Time in Patent Office: 635 Days
• Field of Search: 600/544-5, 600/547
• US Class Current: 600/544
• CPC Class Codes: A61B 5/369 Electroencephalography [EEG] devices for psychotechnics A61B5/16

Abstract

A method and apparatus is described herein for assessing the susceptibility of a patient to stroke. The method begins with the step of collecting electrical signals from the brain of the patient under assessment. Signal data corresponding to the collected electrical signals is then compared to at least one standard. In an embodiment of the invention, the standard represents a neural electrical signal taken from a person known to be susceptible to stroke. A positive comparison result suggests susceptibility of the patient under assessment to stroke. Moreover, the comparison result can be used to characterize the pattern of neural blood flow and the degree of susceptibility to stroke. A strong similarity to a standard taken from another patient of known susceptibility suggests that the patient under assessment is experiencing similar neural blood flow and is susceptible to stroke to a similar degree. This information, in turn, can be used to determine both the need for additional testing and/or the appropriate type and extent of therapy. In an alternative embodiment, the standard represents a neural electrical signal taken from the patient under assessment at an earlier point in time. A positive comparison in this case suggests that the condition of the patient under assessment has not changed. A negative comparison result suggests that the neural electrical activity of the patient under assessment has changed, implying possible changes in neural blood flow. This in turn can suggest susceptibility to stroke and the need for additional tests and/or for pharmaceutical or other therapy. The apparatus for collection of electrical signals from the brain includes a headcap with electrodes concentrated in an area corresponding to a particular cranial region of interest.

Claims

1. A method of determining the susceptibility to suffering a stroke of a patient under assessment, the method comprising the steps of:

(a) collecting electrical signals from the brain of the patient under assessment before the patient under assessment suffers the stroke;

(b) comparing signal data corresponding to the collected electrical signals to at least one standard to produce comparison results, wherein the signal data is derived from the collected electrical signals; and

(c) interpreting the comparison results.

2. The method of claim 1, wherein said step (a) comprises the step of collecting at least one electroencephalograph (EEG).

3. The method of claim 1, wherein said step (a) comprises the steps of:

(i) performing at least one evoked response potential (ERP) trial on the patient under assessment; and

(ii) capturing the electrical signals that result from the at least one ERP trial.

4. The method of claim 1, further comprising the step of:

(d) processing the collected electrical signals to derive signal data for subsequent comparison to the at least one standard;

performed after step (a) and before step (b).

5. The method of claim 4, wherein said step (d) comprises the step of performing noise reduction on the collected electrical signals.

6. The method of claim 4, wherein said step (d) comprises the step of performing feature extraction on the collected electrical signals.

7. The method of claim 4, wherein said step (d) comprises the step of generating a plurality of projections of the collected electrical signals.

8. The method of claim 1, wherein said step (b) comprises the step of comparing the signal data corresponding to the collected electrical signals to at least one standard, wherein the at least one standard comprises signal data from a patient known to be susceptible to stroke.

9. The method of claim 1, wherein said step (b) comprises the step of comparing signal data corresponding to the collected electrical signals to at least one standard, wherein the at least one standard comprises signal data derived from electrical signals that were collected at an earlier time from the patient under assessment.

10. The method of claim 1, wherein said step (b) comprises the step of comparing signal data corresponding to the collected electrical signals to at least one standard using statistical processing.

11. The method of claim 1, wherein said step (b) comprises the step of comparing signal data corresponding to the collected electrical signals to at least one standard using image analysis.

12. The method of claim 1, wherein said step (c) comprises the step of determining whether the patient under assessment is susceptible to suffering a stroke.

13. The method of claim 1, wherein said step (c) comprises the step of determining a degree of susceptibility of the patient under assessment to suffering a stroke.

14. The method of claim 1, wherein said step (c) comprises the step of characterizing a pattern of neural blood flow in the patient under assessment.

15. The method of claim 1, wherein said step a) comprises collecting electrical signals from the surface of the brain of the patient under assessment, using a headcap that comprises a plurality of electrodes concentrated in at least one region of said headcap,

wherein the plurality of electrodes of the at least one region of the headcap are in electrical contact with at least one region of the surface of the brain.

16. The method of claim 15, wherein the at least one region of the surface of the brain comprises a region supplied with blood by the medial cerebral artery.

17. The method of claim 15, wherein the at least one region of the surface of the brain comprises the somatosensory cortex.