Method and system for monitoring physiological conditions

1. A method for providing an indication of a state of awareness for a patient, comprising the steps of:

displaying data of an EEG power spectrum to provide a power versus frequency graph;

determining, using a processor, a frequency value that separates a lower frequency region from a higher frequency region of the EEG power spectrum;

generating, using the processor, a template, wherein the template has a plurality of contiguous angular sections originating at the frequency value; and

providing, using the processor, an indicator of the state of awareness of the patient based on a position of at least a portion of the higher frequency region coinciding with one of the plurality of contiguous angular sections.

2. The method of claim 1 , wherein the plurality of contiguous angular sections has three angular sections.

3. The method of claim 1 , wherein data of the EEG power spectrum is displayed in a log-log arrangement.

4. The method of claim 3 , further comprising:

calculating a first best-fit line for a lower frequency region of the EEG power spectrum; and

calculating at least a second best-fit line for a higher frequency region of the EEG power spectrum.

5. The method of claim 4 , wherein the frequency value is the intersection point of the first and second best-fit lines.

6. The method of claim 5 , further comprising:

providing the indicator of the state of awareness of the patient based on a position of the second best-fit line coinciding with one of the plurality of contiguous angular sections.

7. The method of claim 4 , further comprising:

displaying the first and second best-fit lines.

8. The method of claim 4 , wherein the plurality of contiguous angular sections includes:

a first angular section which represents a region having a first slope steeper than about −40 dB/decade;

a second angular section which represents a region having a second slope more shallow than about −30 dB/decade; and

a third angular section which represents a region between the first and second angular sections.

9. The method of claim 8 , wherein each of the plurality of contiguous angular sections has a respective associated color.

10. The method of claim 9 , further comprising:

determining in which particular one of the plurality of contiguous angular sections the second best-fit line is located; and

wherein providing the indicator includes displaying the respective color associated with the particular one of the plurality of contiguous angular sections.

11. The method of claim 4 , further comprising:

determining the intersection point of the first best-fit line and the second best-fit lines.

12. The method of claim 1 , wherein data of the EEG power spectrum is displayed in a log-linear arrangement.

13. The method of claim 1 , wherein the plurality of contiguous angular sections includes:

a first angular section which represents a region having a first slope steeper than about −40 dB/decade;

a second angular section which represents a region having a second slope more shallow than about −30 dB/decade; and

a third angular section which represents a region between the first and second angular sections.

14. The method of claim 1 , wherein the indicator includes displaying at least a portion of the particular one of the contiguous angular sections of the template generated.

15. The method of claim 1 , further comprising:

selecting the template from among a plurality of different templates based on a characteristic of the patient.

16. An apparatus for providing an indication of a state of awareness for a patient, comprising the steps of:

a receiver configured to acquire an EEG signal;

a visual display screen coupled with the receiver and configured to display data of an EEG power spectrum to provide a power versus frequency graph;

a calculator coupled with the receiver and configured to determine a frequency value that separates a lower frequency region from a higher frequency region of the EEG power spectrum;

the calculator further configured to generate a template, wherein the template has a plurality of contiguous angular sections originating at the frequency value; and

an indicator coupled with the calculator configured to provide an indicator of the state of awareness of the patient based on a position of at least a portion of the higher frequency region coinciding with one of the plurality of contiguous angular sections.

17. The apparatus of claim 16 , wherein the visual display screen is configured to display the EEG power spectrum in a log-log arrangement.

18. The apparatus of claim 17 , wherein the calculator is further configured to:

calculate a first best-fit line for a lower frequency region of the EEG power spectrum;

calculate at least a second best-fit line for a higher frequency region of the EEG power spectrum; and

calculate the an intersection point of the first and second best fit lines, wherein the intersection point is the frequency value that separates a lower frequency region from a higher frequency region of the EEG power spectrum.

19. The apparatus of claim 18 , wherein the plurality of contiguous angular sections includes:

a first angular section which represents a region having a first slope steeper than about −40 dB/decade;

a second angular section which represents a region having a second slope more shallow than about −30 dB/decade; and

a third angular section which represents a region between the first and second angular sections.

20. The apparatus of claim 19 , wherein the indicator is based on a position of the second best-fit line coinciding with one of the plurality of contiguous angular sections.