Method and system for jointly monitoring physiological conditions

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

arranging data of an EEG and EMG power spectrogram to provide power versus frequency in a log-log arrangement;

calculating a first best-fit line for a lower frequency region of the EEG power spectrogram, using a processor;

calculating a second best-fit line for a higher frequency region of the EEG power spectrogram, using a processor;

calculating a third best-fit line for the EMG power spectrogram, using said processor; and

displaying, on a display device, an indication of the state of awareness based on the first, second and third best-fit lines.

2. The method of claim 1 , further comprising the steps of:

acquiring an analog time-domain EEG signal; and

acquiring an analog time-domain EMG signal;

converting the analog time-domain EEG signal into a digital time-domain EEG signal; and

converting the analog time-domain EMG signal into a digital time-domain EMG signal.

3. The method of claim 2 , further comprising the steps of:

transforming the digital time-domain EEG signal to a frequency-domain EEG signal;

transforming the digital time-domain EMG signal to a frequency-domain EMG signal;

calculating the EEG power spectrogram based on the frequency-domain EEG signal; and

calculating the EMG power spectrogram based on the frequency-domain EMG signal.

4. The method of claim 1 , further comprising:

calculating a fourth best-fit line for frequencies below about 2 HZ in the lower frequency region of the EEG power spectrogram.

5. The method of claim 1 , wherein the first and second best-fit lines intersect at an intersection frequency.

6. The method of claim 5 , further comprising:

calculating a first slope of the first best-fit line and a second slope of the second best-fit line.

7. The method of claim 6 , wherein the indication is determined based, at least in part, on a difference between the first and second slopes.

8. The method of claim 7 , wherein the indication is determined, at least in part, on the intersection frequency.

9. The method of claim 1 , wherein the step of displaying further includes the steps of:

displaying the first, second, and third best-fit lines in a near real time manner.

10. The method of claim 1 , wherein the step of displaying further includes:

receiving input to control the display to select from among different display formats.

11. The method of claim 1 , wherein the indication indicates one of REM sleep, non-REM sleep, and awakeness.

12. The method of claim 1 wherein the EEG and EMG spectrograms include frequencies from about 0 Hz to about 130 Hz.

13. An apparatus for providing an indication of a state of awareness for a patient, comprising:

a data formatter configured to arrange data of an EEG power spectrogram and EMG power spectrogram, that provides power versus frequency, in a log-log arrangement;

a first calculator configured to calculate a first best-fit line for a lower frequency region of the EEG power spectrogram;

the first calculator also configured to calculate a second best-fit line for a higher frequency region of the EEG power spectrogram;

the first calculator also configured to calculate a third best-fit line for a region of the EMG power spectrogram; and

a display configured to provide an indication of the state of awareness based on the first, second and third best-fit lines.

14. The apparatus of claim 13 wherein the EEG and EMG spectrograms include frequencies from about 0 Hz to about 130 Hz.

15. The apparatus of claim 13 , further comprising:

an analyzer configured to calculate an intersection frequency of the first and second best-fit lines, a first slope of the first best-fit line, and a second slope of the second best-fit line.

16. The apparatus of claim 15 , wherein the indication is based, at least in part, on a difference between the first and second slopes and the intersection frequency.

17. The apparatus of claim 15 , wherein the analyzer is configured to calculate an intersection frequency of the second and third best-fit lines, and a third slope of the third best-fit line.

18. The apparatus of claim 13 , wherein the first calculator also configured to calculate a fourth best-fit line for a frequency region below the lower frequency region of the EEG power spectrogram.

19. The apparatus of claim 13 , wherein the indication indicates one of REM sleep, non-REM sleep, and awakeness.

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

generating a template, the template representing a state of awareness;

arranging data of a EEG and EMG power spectrogram to provide power versus frequency in a log-log arrangement for frequencies from about 0 Hz to about 130 Hz;

calculating a first best-fit line for a lower frequency region of the EEG power spectrogram, using a processor;

calculating a second best-fit line for a higher frequency region of the EEG power spectrogram, using said processor;

calculating a third best-fit line for a frequency region of the EMG power spectrogram, using said processor

comparing one or more of the first, second, and third best-fit lines with the template to determine a difference; and

displaying, on a display device, an indication of the state of awareness based on the difference.

21. The method of claim 20 , wherein generating a template includes:

averaging previous spectrogram data for the patient for a predetermined time period.

22. The method of claim 20 , wherein generating a template includes:

selecting the template from a plurality of previously acquired spectrogram templates related to the patient.

23. The method of claim 20 , wherein generating a template includes:

selecting the template from a plurality of spectrogram templates related to person physiologically similar to the patient.

24. The method of claim 20 , wherein the template includes physiological parameters in addition to the EEG and EMG spectrogram.

25. The method of claim 24 , wherein the difference relates to one or more of an area under an alpha peak, a center frequency of the alpha-peak, a slope of the first best-fit line, a slope of the second best-fit line, a slope of the third best-fit line, an intersection frequency of the first and second best-fit line; and the physiological parameters.