Apparatus and method for automated compensation of transcutaneous electrical nerve stimulation for temporal fluctuations such as circadian rhythms

1. Apparatus for transcutaneous electrical nerve stimulation in a user, the apparatus comprising:

stimulation means for electrically stimulating at least one nerve with at least one stimulation pulse, wherein the stimulation pulse is delivered to the skin of the patient;

control means connected to said stimulation means for controlling at least one characteristic of said at least one stimulation pulse; and

modulating means connected to the control means for automatically modulating said at least one characteristic of said at least one stimulation pulse according to at least one circadian rhythm;

wherein said at least one characteristic comprises at least one from the group consisting of pulse amplitude, pulse width, pulse charge and pulse frequency.

2. Apparatus according to claim 1 wherein said at least one characteristic is the duration of the therapy session.

3. Apparatus according to claim 1 wherein said at least one characteristic is the time between two consecutive therapy sessions.

4. Apparatus according to claim 1 wherein said modulating means comprises a periodic function.

5. Apparatus according to claim 4 wherein said periodic function is a sinusoid with a 24-hour period.

6. Apparatus according to claim 4 wherein said periodic function is a biphasic square wave with a 24-hour period.

7. Apparatus according to claim 4 wherein said periodic function is a biphasic triangular wave with a 24-hour period.

8. Apparatus according to claim 1 wherein said modulation comprises a multiplication operation.

9. Apparatus according to claim 8 wherein said multiplication is by values ranging from 0.94 to 1.06.

10. Apparatus according to claim 1 wherein said modulation means is initialized according to health conditions of the user.

11. Apparatus according to claim 1 wherein feedback from the user alters said modulation means.

12. Apparatus according to claim 11 wherein said feedback is an indication of pain intensity by the user.

13. Apparatus according to claim 11 wherein said feedback is physiological measurement from the user.

14. Apparatus according to claim 13 wherein said physiological measurement is the user's electrotactile perception threshold.

15. A method for controlling transcutaneous electrical nerve stimulation based on the time of day, the method comprising the steps of:

providing apparatus for transcutaneous electrical nerve stimulation in a user, the apparatus comprising:

stimulation means for electrically stimulating at least one nerve with at least one stimulation pulse, wherein the stimulation pulse is delivered to the skin of the patient;

control means connected to said stimulation means for controlling at least one characteristic of said at least one stimulation pulse; and

modulating means connected to the control means for modulating said at least one characteristic of said at least one stimulation pulse;

wherein said at least one characteristic comprises at least one from the group consisting of pulse amplitude, pulse width, pulse charge and pulse frequency;

determining a time-varying function within a 24-hour period;

using said stimulation means to electrically stimulate at least one nerve; and

modulating at least one characteristic of said electrical stimulation according to the time of day and said time-varying function.

16. A method according to claim 15 wherein said time-varying function is a sinusoid.

17. A method according to claim 15 wherein said time-varying function is a biphasic square wave.

18. A method according to claim 15 wherein said modulation consists of application of a multiplicative factor from said time-varying function to said at least one characteristic of said at least one electrical stimulation pulse.

19. Apparatus for transcutaneous electrical nerve stimulation in a user, the apparatus comprising:

stimulation means for electrically stimulating at least one nerve with at least one stimulation pulse, wherein the stimulation pulse is delivered to the skin of the patient;

control means connected to said stimulation means for controlling at least one characteristic of said at least one stimulation pulse; and

modulating means connected to the control means for automatically modulating said at least one characteristic of said at least one stimulation pulse according to at least one circadian rhythm;

wherein said at least one characteristic comprises at least one from the group consisting of pulse amplitude, pulse width, pulse charge and pulse frequency;

and further wherein the ratio between the duration of a therapy session and the time between two consecutive therapy sessions remains constant.