Selecting therapy cycle parameters based on monitored brain signal

• US 8,914,115 B2
• Filed: 07/26/2010
• Issued: 12/16/2014
• Est. Priority Date: 12/03/2009
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Giftakis, Jonathon E., Stypulkowski, Paul H.
• Primary Examiner(s): Stice, Paula J
• Application Number:
  US12/843,665
• Publication Number:
  US 20110137371A1
• Time in Patent Office: 1,604 Days
• Field of Search: 607/45
• US Class Current: 607/45
• CPC Class Codes: A61B 5/291 for electroencephalography [EEG]
• CPC Class Codes: A61B 5/293 Invasive
• CPC Class Codes: A61B 5/4094 Diagnosing or monitoring seizure diseases, e.g. epilepsy
• CPC Class Codes: A61N 1/36139 with automatic adjustment
• CPC Class Codes: A61N 1/37247 User interfaces, e.g. input or presentation means
• CPC Class Codes: G16H 40/63 for local operation

Abstract

Bioelectrical brain signals may be monitored at one more regions of the brain of a patient by a medical device. The monitored bioelectrical signals may be used to select one or more therapy cycle parameters, e.g., on cycle duration and/or off cycle duration, for therapy delivered to treat a patient disorder. In one example, the off cycle duration of a therapy may be selected based on the washout period determined from sensed brain signals of the patient following delivery of therapy during an on cycle. In another example, the on cycle duration and/or off cycle duration of a therapy may be selected to maintain the value of one or more characteristics of a brain signal (e.g., cortical activity) of patient within a threshold range of a target value defined for the characteristic that is associated with effective treatment of the patient disorder.

Claims

1. A method comprising:

monitoring a brain signal of a patient;

determining a brain state of the patient based on the monitored brain signal;

comparing the determined brain state of the patient to a baseline brain state;

selecting at least one of an on cycle duration or an off cycle duration of a therapy cycle based on the comparison; and

controlling delivery of therapy to the patient according to the at least one selected parameter of the therapy cycle, wherein selecting the at least one of the on cycle duration or the off cycle duration of the therapy cycle based on the comparison comprises selecting the at least one of the on cycle duration or the off cycle duration such that the delivery of therapy maintains the brain signal of the patient within a threshold degree of the baseline brain state.

2. The method of claim 1, wherein monitoring the brain signal of the patient comprises monitoring the brain signal of the patient during an off cycle of the therapy, and wherein determining the brain state comprises determining the brain state of the patient based on the brain signal monitored during the off cycle of the therapy.

3. The method of claim 1, wherein comparing the determined brain state of the patient to the baseline brain state comprises determining whether a characteristic of the determined brain state is within the threshold degree of the baseline brain state.

4. The method of claim 1, further comprising controlling delivery of the therapy to the patient according to a first therapy program for a first on cycle duration, wherein monitoring the brain signal of the patient comprises monitoring the brain signal of the patient following the first on cycle duration, wherein comparing the determined brain state of the patient to the baseline brain state comprises determining a washout period for the therapy based on the monitored brain signal following the first on cycle duration, and wherein selecting the at least one of the on cycle duration or the off cycle duration of the therapy cycle based on the comparison comprises selecting the at least one parameter of the therapy cycle based on the washout period determined for the therapy.

5. The method of claim 1, further comprising

controlling delivery of therapy according to a plurality of therapy programs, wherein monitoring the brain signal of the patient comprises monitoring the brain signal after delivery of therapy according to each therapy program of the plurality of therapy programs, wherein comparing the determined brain state of the patient to the baseline brain state comprises determining a washout period for each therapy program of the plurality of therapy programs based on the respective monitored brain signal, and wherein selecting the at least one of the on cycle duration or the off cycle duration of the therapy cycle based on the comparison comprises selecting the at least one parameter of the therapy cycle for each therapy program of the plurality of therapy programs based on the washout period determined for the respective therapy program.

6. The method of claim 1, further comprising:

controlling delivery of therapy to the patient according to a first therapy program defining at least one therapy parameter value during at least one on cycle, wherein monitoring the brain signal of the patient comprises monitoring the brain signal of the patient following the delivery of therapy during the at least one on cycle; and

adjusting the at least one therapy parameter value defined by the therapy program based on the comparison of the determined brain state to the baseline brain state.

7. The method of claim 1, wherein therapy is delivered to the patient at a first location within a brain of the patient that is different from a second location within the brain in which the brain signal is monitored.

8. The method of claim 1, wherein monitoring the brain signal comprises monitoring at least one of an electroencephalogram (EEG) signal, an electrocorticogram (ECoG) signal, a local field potential (LFP) sensed from within one or more regions of a brain of the patient or an action potential signal from the brain of the patient.

9. The method of claim 1, wherein the therapy is delivered to at least one of an anterior thalamic nucleus, internal capsule, cingulate, fornix, mammillary bodies, mammillothalamic tract, subgenual component of the cingulate cortex, cortex, vagal nerve, or hippocampus of the patient.

10. The method of claim 1, wherein monitoring the brain signal of the patient comprises monitoring the brain signal within one of an anterior thalamic nucleus or hippocampus of a brain of the patient and controlling delivery of the therapy to the patient comprises controlling therapy delivery to the other of the anterior thalamic nucleus or hippocampus of the brain of the patient.

11. The method of claim 1, wherein monitoring the brain signal of the patient comprises monitoring the brain signal within one of an anterior thalamic nucleus or hippocampus of a brain of the patient and controlling delivery of the therapy to the patient comprises controlling therapy delivery to the same of the anterior thalamic nucleus or hippocampus of the brain of the patient.

12. The method of claim 1, wherein selecting the at least one of the on cycle duration or the off cycle duration of the therapy cycle comprises:

selecting a first on cycle;

controlling delivery of therapy to the patient according to the first on cycle;

selecting a first off cycle based on the delivery of therapy according to the first on cycle;

selecting a second on cycle;

controlling delivery of therapy to the patient according to the second on cycle;

selecting a second off cycle based on the delivery of therapy according to the second on cycle; and

selecting a first combination comprising the first on cycle and the first off cycle or a second combination comprising the second on cycle and the second off cycle.

13. The method of claim 1, wherein selecting the at least one of the on cycle duration or the off cycle duration of the therapy cycle comprises:

selecting a plurality of on cycles;

controlling delivery of therapy to the patient according to each on cycle of the plurality of on cycles;

selecting respective off cycles for each on cycle of the plurality of on cycles based on the delivery of therapy according to each on cycle of the plurality of on cycles; and

selecting at least one of the on cycles of the plurality of on cycles and the respective off cycle as the at least one parameter of the therapy cycle.

14. The method of claim 1, wherein selecting the at least one of the on cycle duration or the off cycle duration of the therapy cycle comprises:

selecting an on cycle;

controlling delivery of therapy to the patient according to the on cycle and each of a plurality of off cycles; and

selecting the on cycle and at least one off cycle of the plurality of off cycles as the at least one parameter of the therapy cycle based on the delivery of therapy to the patient according to the on cycle and each of a plurality of off cycles.

15. The method of claim 1, further comprising periodically adjusting the at least one selected parameter of the therapy cycle based at least in part on the brain signal monitored following the selection of the at least one parameter.

16. The method of claim 1, wherein selecting the at least one of the on cycle duration or the off cycle duration such that the delivery of therapy maintains the brain signal of the patient within the threshold degree of the baseline brain state comprises selecting the at least one of the on cycle duration or the off cycle duration such that the delivery of therapy prevents the brain state of the patient from returning to the baseline brain state.

17. The method of claim 1, wherein selecting the at least one of the on cycle duration or the off cycle duration such that the delivery of therapy maintains the brain signal of the patient within the threshold degree of the baseline brain state comprises selecting the at least one of the on cycle duration or the off cycle duration such that the delivery of therapy maintains the brain state of the patient at an activity level below the baseline brain state.

18. A system comprising:

a sensing module configured to monitor a brain signal within a brain of a patient;

a therapy module configured to delivery therapy to the patient; and

a processor configured to determine a brain state of the patient based on the monitored brain signal and to compare the determined brain state of the patient to a baseline brain state, and further configured to select at least one of an on cycle duration or an off cycle duration of a therapy cycle based on the comparison, and control the therapy module to deliver the therapy to the patient according to the at least one selected parameter of the therapy cycle, wherein the processor is configured to select the at least one of the on cycle duration or the off cycle duration such that the delivery of therapy maintains the brain signal of the patient within a threshold degree of the baseline brain state.

19. The system of claim 18, wherein the sensing module is configured to monitor the brain signal of the patient during an off cycle of the therapy, and wherein the processor is configured to determine the brain state based on the brain signal monitored during the off cycle of the therapy.

20. The system of claim 18, wherein the processor is configured to determine whether a characteristic of the determined brain state is within the threshold degree of the baseline brain state.

21. The system of claim 18, wherein the processor is configured to control delivery of the therapy to the patient according to a first therapy program for a first on cycle duration, wherein the sensing module is configured to monitor the brain signal of the patient following the first on cycle duration, and the processor is configured to determine a washout period for the therapy according to the first therapy program based on the brain signal monitored following the first on cycle duration, and select the at least one of the on cycle duration or the off cycle duration of the therapy cycle based on the washout period determined for the therapy according to the first therapy program.

22. The system of claim 18, wherein the processor is configured to control delivery of therapy according to a plurality of therapy programs, wherein the sensing module is configured to monitor the brain signal after delivery of therapy according to each therapy program of the plurality of therapy programs, and the processor is configured to determine a washout period for each therapy program of the plurality of therapy programs based on the respective monitored brain signal, and select the at least one of the on cycle duration or the off cycle duration of the therapy cycle for each therapy program based on the washout period determined for respective therapy programs.

23. The system of claim 18, wherein the processor is configured to monitor the brain signal of the patient following the delivery of therapy during the at least one on cycle and adjust the at least one therapy parameter value defined by the therapy program based on the comparison of the determined brain state to the baseline brain state.

24. The system of claim 18, wherein the therapy module is configured to deliver the therapy to the patient at a first location within a brain of the patient that is different from a second location within the brain in which the brain signal is monitored by the sensing module.

25. The system of claim 18, wherein the sensing module is configured to monitor the brain signal by at least monitoring at least one of an electroencephalogram (EEG) signal, an electrocorticogram (ECoG) signal, a local field potential (LFP) sensed from within one or more regions of a brain of the patient or an action potential signal from the brain of the patient.

26. The system of claim 18, wherein the therapy module is configured to deliver the therapy to at least one of an anterior thalamic nucleus, internal capsule, cingulate, fornix, the mammillary bodies, the mammillothalamic tract, subgenual component of the cingulate cortex, cortex, vagal nerve, or hippocampus of the patient.

27. The system of claim 18, wherein the sensing module is configured to monitor the brain signal of the patient within one of an anterior thalamic nucleus or hippocampus of a brain of the patient, and the processor is configured to control the therapy module to deliver the therapy to the other of the anterior thalamic nucleus or hippocampus of the brain of the patient.

28. The system of claim 18, wherein the sensing module is configured to monitor the brain signal of the patient within one of an anterior thalamic nucleus or hippocampus of a brain of the patient, and the processor is configured to control the therapy module to deliver the therapy to the same of the anterior thalamic nucleus or hippocampus of the brain of the patient.

29. The system of claim 18, wherein the processor is configured to:

select a first on cycle;

control the therapy module to deliver therapy to the patient according to the first on cycle;

select a first off cycle based on the delivery of therapy according to the first on cycle;

select a second on cycle;

control the therapy module to deliver therapy to the patient according to the second on cycle;

select a second off cycle based on the delivery of therapy according to the second on cycle; and

select a first combination comprising the first on cycle and the first off cycle or a second combination comprising the second on cycle and the second off cycle.

30. The system of claim 18, wherein the processor is configured to select a plurality of on cycles;

control the therapy module to deliver therapy to the patient according to each on cycle of the plurality of on cycles;

select respective off cycles for each on cycle of the plurality of on cycles based on the delivery of therapy according to each on cycle of the plurality of on cycles; and

select at least one of the on cycles of the plurality of on cycles and the respective off cycle as the at least one parameter of the therapy cycle.

31. The system of claim 18, wherein the processor is configured to:

select an on cycle;

control the therapy module to deliver therapy to the patient according to the on cycle and each of a plurality of off cycles; and

select the on cycle and at least one off cycle of the plurality of off cycles as the at least one parameter of the therapy cycle based on the delivery of therapy to the patient according to the on cycle and each of a plurality of off cycles.

32. The system of claim 18, wherein the processor is configured to periodically adjust the at least one selected parameter of the therapy cycle based at least in part on the brain signal monitored following the selection of the at least one parameter.

33. The system of claim 18, wherein the processor is configured to select the at least one of the on cycle duration or the off cycle duration such that the delivery of therapy prevents the brain state of the patient from returning to the baseline brain state.

34. The system of claim 18, wherein the processor is configured to select the at least one of the on cycle duration or the off cycle duration such that the delivery of therapy maintains the brain state of the patient at an activity level below the baseline brain state.

35. A system comprising:

means for monitoring a brain signal of a patient;

means for determining a brain state of the patient based on the monitored brain signal;

means for comparing the determined brain state of the patient to a baseline brain state;

means for selecting at least one of an on cycle duration or an off cycle duration of a therapy cycle based on the comparison; and

means for controlling delivery of the therapy to the patient according to the at least one selected parameter of the therapy cycle,

wherein the means for selecting the at least one of the on cycle duration or the off cycle duration of the therapy cycle based on the comparison comprises means for selecting the at least one of the on cycle duration or the off cycle duration such that the delivery of therapy maintains the brain signal of the patient within a threshold degree of the baseline brain state.

36. A non-transitory computer-readable storage medium comprising instructions that cause a programmable processor to:

monitor a brain signal of a patient;

determine a brain state of the patient based on the monitored brain signal;

compare the monitored brain state of the patient to a baseline brain state;

select at least one of an on cycle duration or an off cycle duration of a therapy cycle based on the determined brain state; and

control delivery of therapy to the patient according to the at least one selected parameter of the therapy cycle,

wherein the at least one of an on cycle duration or an off cycle duration is selected such that the delivery of therapy maintains the brain signal of the patient within a threshold degree of the baseline brain state.