Method and apparatus for distinguishing epileptic seizure and neurocardiogenic syncope

• US 8,738,121 B2
• Filed: 08/23/2010
• Issued: 05/27/2014
• Est. Priority Date: 08/23/2010
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Virag, Nathalie, Markowitz, H. Toby, Vetter, Rolf
• Primary Examiner(s): Layno, Carl H
• Assistant Examiner(s): ANTHONY, JESSICA LYNN
• Application Number:
  US12/861,178
• Publication Number:
  US 20120046558A1
• Time in Patent Office: 1,373 Days
• Field of Search: 600508-509, 600/519, 600/521, 600/544
• US Class Current: 600/521
• CPC Class Codes: A61B 5/0205 Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition
• CPC Class Codes: A61B 5/352 Detecting R peaks, e.g. for synchronising diagnostic apparatus; Estimating R-R interval
• CPC Class Codes: A61B 5/4094 Diagnosing or monitoring seizure diseases, e.g. epilepsy
• CPC Class Codes: A61B 5/7282 Event detection, e.g. detecting unique waveforms indicative of a medical condition A61B5/4094, A61B5/4818, A61B5/349, A61B5/0823 take precedence
• CPC Class Codes: A61N 1/365 controlled by a physiological parameter, e.g. heart potential evoked response A61N1/371
• CPC Class Codes: A61N 1/3702 Physiological parameters A61N1/365 takes precedence; evoked response A61N1/371
• CPC Class Codes: A61N 1/37247 User interfaces, e.g. input or presentation means

Abstract

A system and method for distinguishing an epileptic event from a syncope event that includes sensing a signal, generating sensed intervals in response to the sensed signal, generating an indication signal in response to an occurrence of an event, determining a marginality in response to the generated indication signal and the sensed intervals, and determining the event as being one of the epileptic event and the syncope event in response to the determined marginality.

Claims

1. A medical device system to distinguish an epileptic event from a syncope event, the medical device system comprising:

a monitoring device to sense a signal and generate sensed intervals in response to the signal;

an event indicator device to generate an indication signal corresponding to an occurrence of an event; and

a control unit coupled to the monitoring device and the event indicator device to determine a marginality in response to the indication signal and the sensed intervals, and determine the event as being one of the epileptic event and the syncope event in response to the determined marginality.

2. The medical device system of claim 1, wherein the control unit determines a first marginality corresponding to intervals sensed during a first time period including the generated indication signal and a second marginality corresponding to intervals sensed during a second time period preceding the generated indication signal, and compares the first marginality and the second marginality to determine the event.

3. The medical device system of claim 2, wherein the control unit determines a maximum marginality corresponding to the first time period and compares the second marginality to the maximum marginality.

4. The medical device system of claim 3, wherein the control unit determines the event as being the epileptic event in response to the second marginality being greater than the maximum marginality.

5. The medical device system of claim 3, wherein the control unit determines the event as being the syncope event in response to the second marginality not being greater than the maximum marginality.

6. The medical device system of claim 3, wherein the control unit determines the event as being the epileptic event in response to the second marginality being greater than the maximum marginality, and determines the event as being the syncope event in response to the second marginality not being greater than the maximum marginality.

7. The medical device system of claim 3, wherein the control unit determines the event as being the epileptic event in response to a sum of the second marginality and a predetermined threshold being greater than the maximum marginality, and determines the event as being the syncope event in response to the sum of the second marginality and the predetermined threshold not being greater than the maximum marginality.

8. The medical device system of claim 1, wherein the control unit determines marginalities corresponding to intervals sensed during a time period including the generated indication signal, determines a maximum marginality of the determined marginalities, compares the maximum marginality to a threshold, and determines the event as being one of the epileptic event and the syncope event in response to the comparing.

9. The medical device system of claim 8, wherein the monitoring device determines the event as being the epileptic event in response to the maximum marginality being greater than the threshold, and determines the event as being the syncope event in response to the maximum marginality not being greater than the threshold.

10. The medical device system of claim 1, further comprising an electrode coupled to the monitoring device, wherein the monitoring device senses the signal via the electrode, and wherein the electrode is positioned intravascularly within a patient.

11. The medical device system of claim 1, wherein the monitoring device comprises one of an implantable stimulator, an implantable monitor, or an external monitor.

12. A method of distinguishing an epileptic event from a syncope event in a medical device, comprising:

sensing a signal in the medical device;

generating sensed intervals in the medical device in response to the sensed signal;

generating an indication signal in the medical device in response to an occurrence of an event;

determining a marginality in the medical device in response to the generated indication signal and the sensed intervals; and

determining the event as being one of the epileptic event and the syncope event in the medical device in response to the determined marginality.

13. The method of claim 12, wherein determining a marginality comprises:

determining a first marginality corresponding to intervals sensed during a first time period including the generated indication signal; and

determining a second marginality corresponding to intervals sensed during a second time period preceding the generated indication signal, and wherein determining the event as being one of the epileptic event and the syncope event comprises comparing the first marginality and the second marginality.

14. The method of claim 13, further comprising determining a maximum marginality corresponding to the first time period in the medical device, and wherein determining the event as being one of the epileptic event and the syncope event comprises comparing the second marginality to the maximum marginality.

15. The method of claim 14, wherein determining the event as being one of the epileptic event and the syncope event comprises determining the event as being the epileptic event in response to the second marginality being greater than the maximum marginality.

16. The method of claim 14, wherein determining the event as being one of the epileptic event and the syncope event comprises determining the event as being the syncope event in response to the second marginality not being greater than the maximum marginality.

17. The method of claim 14, wherein determining the event as being one of the epileptic event and the syncope event comprises:

determining the event as being the epileptic event in response to a sum of the second marginality and a predetermined threshold being greater than the maximum marginality; and

determining the event as being the syncope event in response to the sum of the second marginality and the predetermined threshold not being greater than the maximum marginality.

18. The method of claim 12, further comprising:

determining, in the medical device, marginalities corresponding to intervals sensed during a time period including the generated indication signal;

determining, in the medical device, a maximum marginality of the determined marginalities;

comparing, in the medical device, the maximum marginality to a threshold; and

determining, in the medical device, the event as being one of the epileptic event and the syncope event in response to the comparing.

19. The method of claim 18, further comprising:

determining, in the medical device, the event as being the epileptic event in response to the maximum marginality being greater then the threshold; and

determining, in the medical device, the event as being the syncope event in response to the maximum marginality not being greater then the threshold.

20. The method of claim 12, further comprising sensing the signal via an electrode positioned intravascularly within a patient.

21. A non-transitory computer readable medium having computer executable instructions for performing a method in a medical device, the method comprising:

sensing a signal;

generating sensed intervals in response to the sensed signal;

generating an indication signal in response to an occurrence of an event;

determining a marginality in response to the generated indication signal and the sensed intervals; and

determining the event as being one of an epileptic event and a syncope event in response to the determined marginality.

22. The computer readable medium of claim 21, wherein determining a marginality comprises:

determining a first marginality corresponding to intervals sensed during a first time period including the generated indication signal; and

determining a second marginality corresponding to intervals sensed during a second time period preceding the generated indication signal, and wherein determining the event as being one of the epileptic event and the syncope event comprises comparing the first marginality and the second marginality.

23. The computer readable medium of claim 21, wherein determining a marginality comprises:

determining marginalities corresponding to intervals sensed during a time period including the generated indication signal;

determining a maximum marginality of the determined marginalities;

comparing the maximum marginality to a threshold; and

determining the event as being one of the epileptic event and the syncope event in response to the comparing.