TIMING THERAPY EVALUATION TRIALS

• US 20090264967A1
• Filed: 04/17/2009
• Published: 10/22/2009
• Est. Priority Date: 04/18/2008
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Stypulkowski, Paul H., Giftakis, Jonathon E., Denison, Timothy J., Rise, Mark T.
• Granted Patent: US 10,493,281 B2
• Time in Patent Office: Days
• US Class Current: 607/62
• CPC Class Codes: A61N 1/0534 Electrodes for deep brain stimulation
• CPC Class Codes: A61N 1/36082 Cognitive or psychiatric applications, e.g. dementia or Alzheimer's disease
• CPC Class Codes: A61N 1/36135 using physiological parameters
• CPC Class Codes: A61N 1/37211 Means for communicating with stimulators
• CPC Class Codes: A61N 1/37247 User interfaces, e.g. input or presentation means

Abstract

A characteristic of a washout period following the delivery of therapy to a patient according to a therapy program may be determined based on a physiological parameter of the patient. A washout period includes the period of time during which a carryover effect from the therapy delivery dissipates. Monitoring a washout period may be useful for timing the delivery of therapy according to different therapy programs during a therapy evaluation period. For example, at least one physiological signal of the patient may be monitored to automatically determine when a washout period has ended, e.g., when stimulation and carryover effects of therapy delivery according to a first therapy program have substantially dissipated, in order to determine when therapy delivery according to a second therapy program can be initiated.

Claims

1. A method comprising:

receiving a signal indicative of a physiological parameter of a patient during a first period during which therapy according to a first therapy program is delivered to the patient;

detecting a carryover effect from the delivery of the therapy according to the first therapy program based on the signal, wherein the carryover effect occurs during a washout period following the first period; and

automatically initiating delivery of therapy to the patient according to a second therapy program at a time based on the washout period.

2. The method of claim 1, wherein the signal indicative of the physiological parameter comprises a first signal indicative of a first physiological parameter of the patient, the method further comprising receiving a second signal indicative of a second physiological parameter of the patient, wherein detecting the carryover effect comprises detecting the carryover effect based on the first and second signals.

3. The method of claim 1, wherein the time based on the washout period comprises at least one of the end of the washout period or after the end of the washout period.

4. The method of claim 1, wherein detecting the carryover effect from delivery of the therapy according to the first therapy program comprises detecting a change in the signal from a baseline state of the signal during a second period following the first period.

5. The method of claim 4, wherein initiating the delivery of therapy to the patient according to the second therapy program comprises determining when the signal returns to the baseline state during the second period and initiating the delivery of therapy when the signal returns to the baseline state during the second period.

6. The method of claim 5, further comprising, after determining when the signal returns to the baseline state during the second period, determining whether a minimum waiting period has expired following the first period prior to initiating the delivery of therapy to the patient according to the second therapy program.

7. The method of claim 4, wherein the signal indicative of the physiological parameter comprises a first signal indicative of a first physiological parameter of the patient, the change in the first signal from a baseline state comprises a first change in the first signal from a first baseline state of the first signal, the method further comprising receiving a second signal indicative of a second physiological parameter of the patient, wherein detecting the carryover effect comprises detecting the first change in the first signal from the first baseline state during the second period, and detecting a second change in the second signal from a second baseline state of the second signal during the second period.

8. The method of claim 7, wherein initiating the delivery of therapy to the patient according to the second therapy program comprises determining when the first signal returns to the first baseline state during the second period and when the second signal returns to the second baseline state during the second period, and initiating the delivery of therapy when the first signal returns to the first baseline state and the second signal returns to the second baseline state during the second period.

9. The method of claim 7, wherein initiating the delivery of therapy to the patient according to the second therapy program comprises determining when the first signal returns to the first baseline state during the second period or when the second signal returns to the second baseline state during the second period, and initiating the delivery of therapy when either the first signal returns to the first baseline state or the second signal returns to the second baseline state during the second period.

10. The method of claim 1, wherein automatically initiating the delivery of therapy to the patient according to the second therapy program comprises determining when the signal returns to a first state during a second period immediately following the first period.

11. The method of claim 10, further comprising determining the first state prior to delivery of the therapy according to the first therapy program.

12. The method of claim 10, wherein the carryover effect comprises a first carryover effect, the washout period comprises a first washout period, and the time comprises a first time, the method further comprising:

receiving the signal during a third period during which therapy according to the second therapy program is delivered to the patient;

detecting a second carryover effect from the delivery of the therapy according to the second therapy program based on the signal, wherein the second carryover effect occurs during a second washout period following the third period; and

automatically initiating delivery of therapy to the patient according to a third therapy program at a second time based on the second washout period.

13. The method of claim 12, wherein the automatically initiating delivery of therapy to the patient according to a third therapy program at a second time based on the second washout period comprises determining when the signal returns to the first state during a fourth period immediately following the third period.

14. The method of claim 12, further comprising determining a second state of the signal prior to the delivery of therapy according to the second therapy program, wherein automatically initiating delivery of therapy to the patient according to a third therapy program at a second time based on the second washout period comprises determining when the signal returns to the second state during a fourth period immediately following the third period.

15. The method of claim 1, wherein the therapy comprises at least one of electrical stimulation therapy or therapeutic agent delivery therapy.

16. The method of claim 1, wherein detecting the carryover effect comprises comparing an amplitude of the signal, a power level in a frequency band of the signal or a ratio of power levels in two or more frequency bands of the signal to a threshold value.

17. The method of claim 16, wherein comparing the amplitude to the threshold value comprises comparing at least one of a peak amplitude, average amplitude or median amplitude of the signal during a sample period to the threshold value.

18. The method of claim 16, further comprising determining the time, wherein determining the time comprises determining the time based on when the amplitude of the signal falls to or below the threshold value.

19. The method of claim 1, wherein detecting the carryover effect comprises comparing a trend in the signal to a template.

20. The method of claim 1, further comprising applying a stimulus to decrease a duration of the washout period.

21. The method of claim 1, wherein receiving the signal of the patient comprises receiving a signal indicative of at least one of a heart rate, respiratory rate, electrodermal activity, facial electromyogram or thermal activity of the patient.

22. The method of claim 1, wherein automatically initiating the delivery of therapy to the patient according to the second therapy program comprises generating an indication to a user to notify the user of the delivery of therapy or to seek approval prior to delivering of the therapy according to the second therapy program.

23. A method comprising:

establishing a baseline state of a physiological signal of a patient;

delivering electrical stimulation therapy to a patient according to a first therapy program during a stimulation period;

monitoring the physiological signal of the patient during a post-stimulation period following the stimulation period;

automatically determining when the physiological signal returns to first state that is based on the baseline state; and

automatically delivering electrical stimulation therapy to the patient according to a second therapy program after the physiological signal returns to the first state.

24. The method of claim 23, wherein the first state comprises the baseline state.

25. The method of claim 23, further comprising, after determining when the physiological signal returns to the first state, automatically determining whether a minimum time has passed prior to delivering electrical stimulation therapy to the patient according to the second therapy program.

26. A system comprising:

a sensor that generates a signal as a function of a physiological parameter of a patient;

a medical device that delivers therapy to the patient according to a first therapy program during a first period; and

a processor that receives the signal from the sensor during a second period following the first period, detects a carryover effect from delivery of the therapy according to the first therapy program based on the signal, wherein the carryover effect occurs during a washout period during the second period, and automatically controls the medical device to deliver therapy to the patient according to a second therapy program at a time based on the washout period.

27. The system of claim 26, wherein the processor generates an indication to a user to notify the user of the delivery of therapy or to seek approval prior to controlling the medical device to deliver the therapy according to the second therapy program

28. The system of claim 26, wherein the processor detects the carryover effect from delivery of the therapy according to the first therapy program by, during the second period, detecting a change in the signal from a first state of the signal.

29. The system of claim 28, wherein the first state comprises a baseline state of the signal that is determined prior to the first period.

30. The system of claim 29, wherein the processor determines when the signal returns to the baseline state during the second period and automatically controls the medical device to deliver therapy to the patient after the signal returns to the baseline state during the second period.

31. The system of claim 30, wherein, after determining when the signal to return to the baseline state during the second period, the processor determines whether a minimum waiting period has expired following the first period prior to controlling the delivery of therapy to the patient according to the second therapy program.

32. The system of claim 26, wherein the processor initiates the delivery of a stimulus to the patient to decrease a duration of the washout period.

33. The system of claim 26, wherein the sensor generates the signal as a function of at least one of a heart rate, respiratory rate, electrodermal activity, facial electromyogram or thermal activity of the patient.

34. A system comprising:

means for receiving a signal indicative of a physiological parameter of a patient during a first period during which therapy according to a first therapy program is delivered to the patient;

means for detecting a carryover effect from the delivery of the therapy according to the first therapy program based on the signal, wherein the carryover effect occurs during a washout period following the first period; and

means for automatically initiating delivery of therapy to the patient according to a second therapy program at a time based on the washout period.

35. The system of claim 34, further comprising means for applying a stimulus to decrease a duration of the washout period.