System and method for monitoring or treating nervous system disorders

• US 20060135881A1
• Filed: 12/19/2005
• Published: 06/22/2006
• Est. Priority Date: 12/17/2004
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Giftakis, Jonathon E., Graves, Nina M.
• Granted Patent: US 7,945,316 B2
• Time in Patent Office: Days
• US Class Current: 600/544
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• CPC Class Codes: A61B 5/02 Detecting, measuring or recording pulse, heart rate, blood pressure or blood flow; Combined pulse/heart-rate/blood pressure determination; Evaluating a cardiovascular condition not otherwise provided for, e.g. using combinations of techniques provided for in this group with electrocardiography or electroauscultation; Heart catheters for measuring blood pressure
• CPC Class Codes: A61B 5/0245 by using sensing means generating electric signals, i.e. ECG signals
• CPC Class Codes: A61B 5/053 Measuring electrical impedance or conductance of a portion of the body
• CPC Class Codes: A61B 5/08 Detecting, measuring or recording devices for evaluating the respiratory organs A61B5/0205 takes precedence
• CPC Class Codes: A61B 5/0816 Measuring devices for examining respiratory frequency measuring frequency of electric signals G01R23/00
• CPC Class Codes: A61B 5/1135 by monitoring thoracic expansion
• CPC Class Codes: A61B 5/293 Invasive
• CPC Class Codes: A61B 5/318 Heart-related electrical modalities, e.g. electrocardiography [ECG]
• CPC Class Codes: A61B 5/349 Detecting specific parameters of the electrocardiograph cycle
• CPC Class Codes: A61B 5/369 Electroencephalography [EEG] devices for psychotechnics A61B5/16
• CPC Class Codes: A61B 5/37 Intracranial electroencephalography [IC-EEG], e.g. electrocorticography [ECoG]
• CPC Class Codes: A61B 5/4094 Diagnosing or monitoring seizure diseases, e.g. epilepsy
• CPC Class Codes: A61N 1/05 for implantation or insertion into the body, e.g. heart electrode A61N1/06 takes precedence
• CPC Class Codes: A61N 1/3601 of respiratory organs
• CPC Class Codes: A61N 1/36082 Cognitive or psychiatric applications, e.g. dementia or Alzheimer's disease
• CPC Class Codes: A61N 1/3614 based on impedance measurement
• CPC Class Codes: A61N 1/3629 in combination with non-electric therapy
• CPC Class Codes: A61N 1/36521 the parameter being derived from measurement of an electrical impedance
• CPC Class Codes: A61N 1/36585 controlled by two or more physical parameters
• CPC Class Codes: A61N 1/37 : Monitoring; Protecting
• CPC Class Codes: A61N 1/37247 : User interfaces, e.g. input or presentation means
• CPC Class Codes: A61N 1/37282 : characterised by communication with experts in remote locations using a network
• CPC Class Codes: A61N 1/37288 : Communication to several implantable medical devices within one patient
• CPC Class Codes: A61N 1/39622 : Pacing therapy

Abstract

A medical device system for comparing a cardiopulmonary signal to a brain signal. In one embodiment of the invention, a medical device system is provided that includes a brain monitoring element, respiratory monitoring element and a processor. The processor is configured to receive a brain signal from the brain monitoring element and a respiratory signal from the respiratory monitoring element. The processor is further configured to compare the brain signal to the respiratory signal. Methods of comparing a brain signal to a cardiopulmonary signal are also provided.

Claims

1. A medical device system comprising:

(a) a brain monitoring element for sensing activity of the brain and outputting a brain signal;

(b) a respiratory monitoring element for sensing activity of the respiratory system and outputting a respiratory signal; and

(c) a processor in communication with the brain monitoring element and the respiratory monitoring element, the processor configured to;

(i) receive the brain signal;

(ii) receive the respiratory signal; and

(iii) compare the brain signal to the respiratory signal.

2. The medical device system of claim 1 wherein the processor is further configured to obtain information identifying one or more neurological events in the brain signal, and causing the processor to obtain information identifying one or more respiratory events in the respiratory signal.

3. The medical device system of claim 2 wherein the medical device system includes a user interface for display of the brain signal and the respiratory signal, the user interface in communication with the processor, and wherein the processor being configured to obtain information identifying one or more neurological events in the brain signal comprises the processor being configured to receive a start point and an end point of each neurological event from a user via the user interface, and wherein the processor being configured to obtain information identifying one or more respiratory events in the respiratory signal comprises the processor being configured to receive a start point and an end point of each respiratory event from a user via the user interface.

4. The medical device system of claim 2 wherein the processor being configured to obtain information identifying one or more neurological events in the brain signal comprises the processor being configured to detect one or more neurological events from the brain signal, and wherein the processor being configured to obtain information identifying one or more respiratory events in the respiratory signal comprises the processor being configured to detect one or more respiratory events from the respiratory signal.

5. The medical device system of claim 2 wherein the processor being configured to compare the brain signal to the respiratory signal comprises the processor being configured to perform the following:

(a) for each of the one or more neurological events, determining whether said neurological event is within a specified time period of one of the one or more respiratory events; and

(b) for each of the one or more respiratory events, determining whether said respiratory event is within a specified time period of one of the one or more neurological events.

6. The medical device system of claim 5 wherein the processor being configured to compare the brain signal to the respiratory signal further comprises the processor being configured to perform the following:

(a) determining the number of neurological events within the specified time period of a respiratory event;

(b) determining the number of neurological events that are not within the specified time period of a respiratory event; and

(c) determining the number of respiratory events that are not within the specified time period of a neurological event.

7. The medical device system of claim 5 wherein the processor further performs the following for the neurological events within the specified time period of a respiratory event:

(a) determining the temporal order of the neurological event and the respiratory event.

8. The medical device system of claim 7 wherein the processor further performs the step of determining the amount of time between the neurological event and the respiratory event.

9. The medical device system of claim 8 wherein determining the amount of time between the neurological event and the respiratory event comprises comparing a first reference point indicative of the temporal location of the neurological event to a second reference point indicative of temporal location of the respiratory event.

10. The medical device system of claim 5 wherein the specified time period is programmable.

11. The medical device system of claim 2 wherein comparing the brain signal to the respiratory signal performed by the processor comprises:

(a) categorizing the neurological event as respiratory matched when there is a respiratory event in close temporal relationship with the neurological event; and

(b) computing a rate of concordance between the neurological events and the respiratory events based on the number of respiratory matched events and the number of neurological events.

12. The medical device system of claim 11 wherein computing the rate of concordance by the processor comprises calculating the number of respiratory matched events divided by the number of neurological events.

13. The medical device system of claim 2 wherein the processor is further configured to perform the following:

(a) dividing the neurological event into at least two segments; and

(b) assigning the respiratory event to one or more of the segments according to when the respiratory event occurred relative to the segments.

14. The medical device system of claim 13 wherein the neurological event is a seizure and the at least two segments comprise three segments comprising a pre-ictal segment, an ictal segment and a post-ictal segment.

15. The medical device system of claim 1 wherein the processor is further configured to enable a respiratory event detection algorithm for detection of a neurological event, based on the results of comparing the brain signal to the respiratory signal.

16. The medical device system of claim 15 further comprising a neurological therapy delivery module, wherein the neurological therapy delivery module is configured to provide a therapeutic output to treat a neurological disorder when the respiratory event detection algorithm detects a respiratory event.

17. The medical device system of claim 2 wherein the processor is further configured to obtain information categorizing each respiratory event as one or more of first type respiratory event and second type respiratory event.

18. The medical device system of claim 17 wherein the first type respiratory event and second type respiratory event are selected from the group consisting of increased respiration rate, change in tidal volume, apnea, prolonged pauses.

19. The medical device system of claim 17 wherein comparing the brain signal to the respiratory signal performed by the processor comprises:

(a) categorizing the neurological event as first type respiratory matched when there is a first type respiratory event within a specified time period of the neurological event;

(b) categorizing the neurological event as second type respiratory matched when there is a second type respiratory event within a specified time period of the neurological event;

(c) computing a first rate of concordance between the neurological events and the first type respiratory events based on the number of first type respiratory matched events and the number of neurological events; and

(d) computing a second rate of concordance between the neurological events and the second type respiratory events based on the number of second type respiratory matched events and the number of neurological events.

20. The medical device system of claim 19 wherein the processor is further configured to enable the use of the detection of a first type respiratory event for detection of a neurological event based on the first rate of concordance.

21. The medical device system of claim 1 wherein the processor is housed in a device external to a human body.

22. The medical device system of claim 1 wherein the processor is configured to be implanted in a human body.

39. The medical device system of claim 1 further comprising a cardiac monitoring element for sensing activity of the cardiac system and outputting a cardiac signal, and wherein the processor is further configured to receive the cardiac signal and compare the brain signal to the cardiac signal.

23. A medical device system comprising:

(a) brain monitoring means for sensing activity of the brain and outputting a brain signal;

(b) respiratory monitoring means for sensing activity of the respiratory system and outputting a respiratory signal; and

(c) processing means for receiving the brain signal, receiving the respiratory signal, and comparing the brain signal to the respiratory signal.

24. The medical device system of claim 23 wherein the processing means further comprises:

(d) neurological event detection means for evaluating the brain signal and identifying one or more neurological events; and

(e) respiratory event detection means for evaluating the respiratory signal and identifying one or more respiratory events.

25. The medical device system of claim 24 wherein the processing means further comprises:

concordance means for determining a rate of concordance between the neurological events and the respiratory events.

26. A method of comparing a brain signal to a respiratory signal comprising:

(a) receiving a brain signal for a period of time;

(b) receiving a respiratory signal for the period of time;

(c) identifying one or more neurological events from the brain signal;

(d) identifying one or more respiratory events from the respiratory signal;

(e) categorizing each of the identified neurological events as respiratory matched when there is a respiratory event within a specified time period of the neurological event; and

(f) computing a rate of concordance between the neurological events and the respiratory events based on the number of respiratory matched events and the number of neurological events.

27. The method of claim 26 wherein computing the rate of concordance comprises determining the number of respiratory matched events divided by the number of neurological events.

28. The method of claim 26 wherein the identifying one or more neurological events from the brain signal comprises applying a neurological event detection algorithm to the brain signal.

29. The method of claim 26 wherein the identifying one or more respiratory events from the respiratory signal comprises applying a respiratory event detection algorithm to the respiratory signal.

30. The method of claim 26 further comprising:

(i) for each neurological event categorized as respiratory matched, determining the temporal order of the neurological event and the respiratory event that is within a specified time period of the neurological event.

31. The method of claim 30 further comprising:

(j) categorizing each of the respiratory events as respiratory unmatched when there is no neurological event within a specified time period of the respiratory event.

32. The method of claim 31 further comprising:

(j) determining whether neurological event detection is improved by using the respiratory signal.

33. The method of claim 32 wherein determining whether the neurological event detection is improved comprises considering the rate of concordance, the temporal order of the respiratory matched events, and the number of respiratory unmatched events.

34. The method of claim 32 further comprising activating a respiratory event detection algorithm for use in neurological event detection based on a determination that the neurological event detection is improved by using the respiratory signal.

35. The method of claim 34 wherein the neurological event to be detected by the respiratory event detection algorithm is a seizure.

36. A computer readable medium containing executable instructions causing a processor to perform the following:

(a) receiving a brain signal from a brain monitoring element;

(b) receiving a respiratory signal from a respiratory monitoring element; and

(c) comparing the brain signal to the respiratory signal.

37. The computer readable medium of claim 36 wherein the step of comparing the brain signal to the respiratory signal comprises:

(a) detecting one or more neurological events in the brain signal;

(b) detecting one or more respiratory events in the respiratory signal;

(c) for each of the one or more neurological events, determining whether said neurological event is within a specified time period of one of the one or more respiratory events; and

(d) for each of the one or more respiratory events, determining whether said respiratory event is within a specified time period of one of the one or more neurological events.

38. The computer readable medium of claim 37 wherein the step of comparing the brain signal to the respiratory signal further comprises:

(a) determining the temporal order of the neurological event and the respiratory event that is within a specified time period of the neurological event.

40. A medical device system comprising:

(a) a brain monitoring element for sensing activity of the brain and outputting a brain signal;

(b) a cardiopulmonary monitoring element for sensing activity of the cardiopulmonary system and outputting a cardiopulmonary signal; and

(c) a processor in communication with the brain monitoring element and the cardiopulmonary monitoring element, the processor configured to;

(i) receive the brain signal;

(ii) receive the cardiopulmonary signal; and

(iii) compare the brain signal to the cardiopulmonary signal.

41. The medical device system of claim 40 wherein the cardiopulmonary signal comprises a cardiac signal and a respiratory signal and the processor configured to compare the brain signal to the cardiopulmonary signal comprises comparing the brain signal to the cardiac signal and comparing the brain signal to the respiratory signal.