METHOD AND DEVICE FOR DETERMINING BRAIN AND SCALP STATE

• US 20150025352A1
• Filed: 07/22/2013
• Published: 01/22/2015
• Est. Priority Date: 07/22/2013
• Status: Abandoned Application

• Current Assignee: Nuraleve Inc.
• Original Assignee: NorDocs Technologies Inc.
• Inventors: Batkin, Izmail, Caytak, Herschel B., Mekonnen, Abeye
• Application Number:
  US13/947,920
• Publication Number:
  US 20150025352A1
• Time in Patent Office: Days
• US Class Current: 600/383
• CPC Class Codes: A61B 5/0531 Measuring skin impedance
• CPC Class Codes: A61B 5/4064 Evaluating the brain A61B5/031, A61B5/369, A61B5/14553 take precedence
• CPC Class Codes: A61B 5/6814 Head
• CPC Class Codes: A61B 5/7246 using correlation, e.g. template matching or determination of similarity
• CPC Class Codes: A61B 5/7267 involving training the classification device
• CPC Class Codes: G16H 50/70 for mining of medical data, e.g. analysing previous cases of other patients

Abstract

A method for determining brain state has the steps of attaching at least 2 first electrodes to the scalp of a subject at a separation, transmitting an electrical current between the at least 2 first electrodes, and measuring a first impedance between the at least 2 first electrodes to provide a resulting impedance. One embodiment has the further step of comparing the resulting impedance to pre-stored impedance measurements of the scalp to determine normal or pathological state. A further embodiment has the steps of attaching 2 first electrodes to the scalp of a subject at a separation and 2 second electrodes, transmitting a current between the first electrodes and measuring a first impedance between the second electrodes to provide a resulting impedance. The electrodes may be driven shield electrodes, and the method may further include comparing impedance measurements to pre-stored impedance measurements to determine normal and pathological state.

Claims

1. A method for determining brain state comprising the steps of:

a) attaching at least 2 first electrodes to the scalp of a subject at a separation;

b) transmitting an electrical current between the at least 2 first electrodes wherein the current has one or more frequencies within a predetermined frequency spectrum; and

c) measuring a first impedance between the at least 2 first electrodes to provide a resulting impedance.

2. The method of claim 1 further comprising the step of:

d) comparing the resulting impedance to pre-stored impedance measurements of the scalp for normal and pathological state.

3. The method of claim 1 wherein the at least 2 first electrodes are positioned in a combined electrode unit having a center electrode and a peripheral electrode having a separation between wherein the separation is less than a maximum scalp thickness further comprising the step of:

d) comparing the resulting impedance to pre-stored impedance measurements of the scalp for normal and pathological state.

4. The method of claim 1 wherein scalp impedance measurements are measured over a plurality of points on the scalp using more than one combined electrode units further comprising the step of:

d) comparing the resulting impedance to pre-stored impedance measurements of the scalp for normal and pathological state.

5. The method of claim 1 wherein the separation between the at least 2 first electrodes is less than maximum scalp thickness, the method further comprising the steps of:

d) attaching a reference electrode to the scalp of a subject wherein the separation between the reference electrode and at least one of the 2 first electrodes is at least maximum scalp thickness;

e) transmitting a electrical current between the at least one of the 2 first electrodes and the reference electrode having a separation at least maximum scalp thickness wherein the current has one or more frequencies within a predetermined frequency spectrum;

f) measuring a second impedance between the at least one of the 2 first electrodes and the reference electrode having a separation at least maximum scalp thickness;

g) subtracting the first impedance from the second impedance to provide a resulting impedance; and

h) comparing the resulting impedance to pre-stored impedance measurements for normal and pathological state.

6. The method of claim 5 wherein the at least 2 first electrodes are positioned in a combined electrode unit having a center electrode and a peripheral electrode having a separation between wherein the separation is less than a maximum scalp thickness and wherein the second impedance is measured between the center electrode of the combined electrode unit and the reference electrode.

7. The method according to claim 1, further comprising the steps of:

a) continually evaluating bioimpedance measurements for existence and degree of abnormality;

b) storing the information in the subject history; and

c) treating the subject with a neuromodulatory technique.

8. The method of claim 1 wherein the at least 2 first electrodes are positioned in a combined electrode unit having a center electrode and a peripheral electrode having a separation between wherein the separation is less than a maximum scalp thickness method further comprising:

d) attaching at least a reference electrode to the scalp of a subject;

e) attaching at least a first voltage electrode and second voltage electrode to the scalp of the subject where the separation between the voltage electrodes and the at least a third electrode is at least the maximum scalp thickness

f) transmitting a predetermined electrical current between one first electrode comprised of a center electrode of the combined electrode unit and the reference electrode wherein the current has one or more frequencies within a predetermined frequency spectrum;

g) measuring a second impedance between the first voltage electrode and the second voltage electrodes;

h) subtracting the first impedance from the second impedance to provide a resulting impedance; and

i) comparing the resulting impedance to pre-stored impedance measurements for normal and pathological state.

9. The method of claim 1 wherein the at least 2 first electrodes are positioned in a combined electrode unit having a center electrode and a peripheral electrode having a separation between wherein the separation is less than a maximum scalp thickness method further comprising:

d) attaching at least a current electrode to the scalp of a subject;

e) attaching at least a reference electrode to the scalp of a subject;

f) attaching at least a first voltage electrode and second voltage electrode to the scalp of the subject where the separation between the voltage electrodes and the at least a current electrode is at least the maximum scalp thickness;

g) transmitting a predetermined electrical current between the current electrode and the reference electrode wherein the current has one or more frequencies within a predetermined frequency spectrum;

h) measuring a second impedance between the first voltage electrode and the second voltage electrodes;

i) subtracting the first impedance from the second impedance to provide a resulting impedance; and

j) comparing the resulting impedance to pre-stored impedance measurements for normal and pathological state.

16. The method of claim 1 wherein the at least 2 first electrodes are comprised of a center and peripheral electrode of a combined electrode unit wherein the predetermined distance between the at least 2 first electrodes is at least maximum scalp thickness method further comprising the steps of:

d) attaching at least 1 driven shield combined electrode unit to the scalp of the subject;

e) transmitting a predetermined electrical current between the center electrode of at least 1 combined electrode unit and the reference electrode, wherein the current has one or more frequencies within a predetermined frequency spectrum;

f) measuring a second impedance between 2 center electrodes comprised of 1 center electrode of the combined electrode unit and 1 center electrode of the driven shield combined electrode unit;

g) subtracting the first impedance from the second impedance to provide a resulting impedance measurement; and

h) comparing the resulting impedance measurements to pre-stored impedance measurements for normal and pathological state.

17. The method of claim 1 wherein the at least 2 first electrodes are comprised of a center and peripheral electrode of a combined electrode unit wherein the predetermined distance between the at least 2 first electrodes is at least maximum scalp thickness method further comprising the steps of:

d) attaching at least 2 driven shield combined electrode units to the scalp of the subject;

e) attaching at least 1 reference electrode to the scalp of the subject;

f) transmitting a predetermined electrical current between the center electrode of at least 1 combined electrode unit and 1 reference electrode wherein the current has one or more frequencies within a predetermined frequency spectrum;

g) measuring the impedance between the center electrodes of the at least 2 driven shield combined electrode units;

h) subtracting the first impedance from the second impedance to provide a resulting impedance measurement; and

i) comparing the resulting impedance measurements to pre-stored impedance measurements for normal and pathological state.

18. The method of claim 1 wherein the at least 2 first electrodes are comprised of a center and peripheral electrode of a combined electrode unit wherein the predetermined distance between the at least 2 first electrodes is at least maximum scalp thickness method further comprising the steps of:

d) attaching at least 3 driven shield combined electrode units to the scalp of the subject;

e) attaching at least 1 reference electrode to the scalp of the subject;

f) transmitting a predetermined electrical current between the center electrode of at least 1 driven shield combined electrode unit and 1 reference electrode wherein the current has one or more frequencies within a predetermined frequency spectrum;

g) measuring the impedance between the center electrodes of the at least 2 driven shield combined electrode units;

h) subtracting the first impedance from the second impedance to provide a resulting impedance measurement; and

i) comparing the resulting impedance measurements to pre-stored impedance measurements for normal and pathological state.

10. A method for determining brain state comprising the steps of:

a) attaching at least 2 first electrodes to the scalp of a subject at a separation;

b) attaching at least 2 second electrodes to the scalp of the subject;

c) transmitting a predetermined electrical current between the at least 2 first electrodes wherein the current has one or more frequencies within a predetermined frequency spectrum;

d) measuring a first impedance between the at least 2 second electrodes to provide a resulting impedance.

11. The method of claim 10 wherein the at least 2 first electrodes are comprised of a current electrode and a reference electrode, wherein the separation between the at least 2 first electrodes is at least maximum scalp thickness and wherein the 2 second electrodes consist of the current electrode and the center electrode of a combined electrode unit wherein a potential measured at the center electrode is forced onto the peripheral electrode by an operational amplifier, method further comprising:

d) comparing the resulting impedance measurements to pre-stored impedance measurements for normal and pathological state.

12. The method of claim 10 wherein the at least 2 first electrodes are comprised of a center electrode of a driven shield combined electrode unit and a reference electrode, wherein the predetermined distance between the at least 2 first electrodes is at least maximum scalp thickness and wherein the at least 2 second electrodes are comprised of 2 center electrodes of 2 driven shield combined electrode units method further comprising the step of:

d) comparing the resulting impedance measurements to pre-stored impedance measurements for normal and pathological state.

13. The method of claim 10 wherein the at least 2 first electrodes are comprised of a current electrode and a reference electrode, wherein the predetermined distance between the 2 first electrodes is at least maximum scalp thickness and wherein the at least 2 second electrodes are comprised of 2 center electrodes of 2 driven shield combined electrode unit method further comprising the step of:

d) comparing the resulting impedance measurements to pre-stored impedance measurements for normal and pathological state.

14. The method of claim 10 wherein the at least 2 first electrodes are comprised of a center electrode of a driven shield combined electrode unit and a reference electrode, wherein the predetermined distance between the at least 2 first electrodes is at least maximum scalp thickness and wherein the at least 2 second electrodes are comprised of 2 center electrodes of 2 driven shield combined electrode units method further comprising the step of:

d) comparing the resulting impedance measurements to pre-stored impedance measurements for normal and pathological state.

15. The method according to claim 10, further comprising the steps of:

a) continually evaluating bioimpedance measurements for existence and degree of abnormality;

b) storing the information in the subject history; and

c) treating the subject with a neuromodulatory technique.

19. A combined electrode unit for determining scalp state comprising:

1) an inner electrode having a central conductive area;

2) a surrounding non-conductive insulating area; and

3) an outer electrode consisting of a peripheral conductive area

wherein a separation between an edge of the central conductive area and the peripheral conductive area is less than maximum scalp thickness.

20. The electrode according to claim 19 wherein the voltage measured at the inner electrode is forced on the peripheral conductive area by an operational amplifier.