Clustering of recorded patient neurological activity to determine length of a neurological event

• US 7,280,867 B2
• Filed: 10/15/2003
• Issued: 10/09/2007
• Est. Priority Date: 10/15/2002
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Frei, Mark G., Osorio, Ivan, Giftakis, Jonathon E., Graves, Nina M., Rise, Mark T., Schaffner, Scott F., Carlson, David L.
• Primary Examiner(s): Marmor, II; Charles A.
• Assistant Examiner(s): Toth; Karen E.
• Application Number:
  US10/687,571
• Publication Number:
  US 20040138536A1
• Time in Patent Office: 1,455 Days
• Field of Search: 600/544, 600/545
• US Class Current: 600/544
• CPC Class Codes: A61B 5/316 Modalities, i.e. specific diagnostic methods
• CPC Class Codes: A61B 5/369 Electroencephalography [EEG] devices for psychotechnics A61B5/16
• CPC Class Codes: A61B 5/4094 Diagnosing or monitoring seizure diseases, e.g. epilepsy
• CPC Class Codes: A61B 5/7217 of noise originating from a therapeutic or surgical apparatus, e.g. from a pacemaker
• CPC Class Codes: A61N 1/36025 for treating a mental or cerebral condition
• CPC Class Codes: A61N 1/36082 Cognitive or psychiatric applications, e.g. dementia or Alzheimer's disease
• CPC Class Codes: A61N 1/361 Phantom sensations, e.g. tinnitus
• CPC Class Codes: Y10S 128/92 Computer assisted medical diagnostics

Abstract

Apparatus and method detect a detection cluster that is associated with a neurological event, such as a seizure, of a nervous system disorder and update therapy parameters that are associated with a treatment therapy. The occurrence of the detection cluster is detected when the maximal ratio exceeds an intensity threshold. If the maximal ratio drops below the intensity threshold for a time interval that is less than a time threshold and subsequently rises above the intensity threshold, the subsequent time duration is considered as being associated with the detection cluster rather than being associated with a different detection cluster. Consequently, treatment of the nervous system disorder during the corresponding time period is in accordance with one detection cluster. Treatment therapy may be provided by providing electrical stimulation, drug infusion or a combination. Therapy parameters may be updated for each m^th successive group of applications of the treatment therapy or for each n^th detection cluster.

Claims

1. A computer-implemented method for determining a detection cluster that is associated with a neurological event of a nervous system disorder of a patient, the detection cluster being associated with at least one detection that exceeds a predetermined threshold of a measure for a first predetermined time duration, the method comprising the steps of:

(a) receiving a set of at least one signal;

(b) determining an onset of the neurological event based on the set of at least one signal;

(c) determining an end of a neurological event based on the set of at least one signal, wherein the determining is further based on all neurological signals of the set of the at least one signal being less than the predetermined threshold of the measure for a second predetermined time duration; and

(d) clustering a set of at least one detection between the onset and the end of the neurological event.

2. The method of claim 1, wherein the measure is selected from a group consisting of a ratio of a neurological signal and an amplitude of the neurological signal.

3. The method of claim 1, wherein step (b) comprises the step of:

(i) determining a first neurological signal that is not less than the predetermined threshold of the measure for the first predetermined time duration, wherein the first neurological signal is a member of the set of at least one signal.

4. The method of claim 1, further comprising the step of:

(e) determining an occurrence of a detection, wherein the detection is a member of the set of detections.

5. The method of claim 4, wherein step (e) comprises the step of:

(i) if any neurological signal of the set of the at least one signal is not less than the predetermined threshold, recognizing the detection.

6. The method of claim 4, wherein step (e) comprises the step of:

(i) if the first neurological signal is not less than the predetermined threshold, recognizing the detection.

7. A computer-readable medium having computer-executable instructions for performing the steps recited in claim 1.

8. The method of claim 1, wherein the set of at least one detection in (d) comprises a first detection and a second detection.

9. The method of claim 8, wherein the first detection and the second detection are separated by less than a predetermined time constraint.

10. The method of claim 9, wherein the predetermined time constraint is 60 seconds.

11. The method of claim 8, wherein the first detection is based on signals from a first electrode and the second detection is based on signals from a second electrode.

12. A computer-implemented method for determining a detection cluster that is associated with a neurological event of a nervous system disorder of a patient, the detection cluster being associated with at least one detection that exceeds a predetermined threshold of a measure for a first predetermined time duration, the method comprising the steps of:

(a) receiving a set of at least one signal;

(b) determining an onset of the neurological event based on the set of at least one signal;

(c) determining an end of a neurological event based on the set of at least one signal; and

(d) clustering a set of at least a first detection and a second detection between the onset and the end of the neurological event, wherein the clustering comprises;

(i) determining a time interval between the first detection and the second detection, wherein the first detection and the second detection are adjacent detections; and

(ii) if the time interval is less than a second predetermined duration, clustering the first and second detections.

13. An apparatus for determining a detection cluster that is associated with a neurological event of a nervous system disorder, the detection cluster being associated with at least one detection that exceeds a predetermined threshold of a measure for a first predetermined time duration, the apparatus comprising in combination:

a configuration of monitoring elements; and

a processor that is coupled to the configuration of monitoring elements, the processor configured to perform the steps of;

(a) receiving a set of at least one signal;

(b) determining an onset of the neurological event based on the set of at least one signal;

(c) determining an end of a neurological event based on the set of at least one signal, wherein the determining is farther based on all neurological signals of the set of at least one signal being less than the predetermined threshold for a second predetermined time duration; and

(d) clustering a set of detections between the onset and the end of the neurological event.

14. The apparatus of claim 13, wherein step (b) comprises the step of:

(i) determining a first neurological signal that is not less than the predetermined threshold of the measure for the first predetermined time duration, wherein the first neurological signal is a member of the set of at least one signal.

15. The apparatus of claim 13, wherein the processor is configured to perform the farther step of:

(e) determining an occurrence of a detection, wherein the detection is a member of the set of detections.

16. The apparatus of claim 15, wherein step (e) comprises the step of:

(i) if any neurological signal of the set of at least one signal is not less than the predetermined threshold, associating a corresponding time with the detection.

17. The apparatus of claim 15, wherein step (e) comprises the step of:

(i) if the first neurological signal is not less than the predetermined threshold, associating a corresponding time with the detection.

18. The apparatus of claim 15, wherein the determining of an occurrence in (e) is the determining of an occurrence of a first detection and further comprises the determining of an occurrence of a second detection, wherein the first and second detection are members of the set of detections.

19. An apparatus for determining a detection cluster that is associated with a neurological event of a nervous system disorder, the detection cluster being associated with at least one detection that exceeds a predetermined threshold of a measure for a first predetermined time duration, the apparatus comprising in combination:

a configuration of monitoring elements; and

a processor that is coupled to the configuration of monitoring elements, the processor configured to perform the steps of;

(a) receiving a set of at least one signal;

(b) determining an onset of the neurological event based on the set of at least one signal;

(c) determining an end of a neurological event based on the set of at least one signal; and

(d) clustering a set of detections between the onset and the end of the neurological event, the clustering comprising;

(i) determining a time interval between a first detection and a second detection, wherein the first detection and the second detection are adjacent detections; and

(ii) if the time interval is less than a second predetermined duration, clustering the first and second detections.

20. An apparatus for determining a detection cluster that is associated with a neurological event of a nervous system disorder, the detection cluster being associated with at least one detection that exceeds a predetermined threshold of a measure for a first predetermined time duration, the apparatus comprising in combination:

a configuration of monitoring elements; and

a processor that is coupled to the configuration of monitoring elements, the processor configured to perform the steps of;

(a) receiving a set of at least one signal;

(b) determining an onset of the neurological event based on the set of at least one signal;

(c) determining an end of a neurological event based on the set of at least one signal; and

(d) clustering a set of detections that includes a first detection and a second detection between the onset and the end of the neurological event.

21. A method for determining a detection cluster that is associated with a neurological event of a nervous system disorder, comprising:

(a) receiving a set of at least one signal;

(b) determining an onset of the neurological event based on the set of at least one signal;

(c) determining an end of a neurological event based on the set of at least one signal; and

(d) clustering a set of detections that includes at least a first detection and a second detection between the onset and the end of the neurological event, the first detection exceeding a predetermined threshold for a predetermined period.

22. The method of claim 21, wherein the first and second detection are separated by a period of time where the predetermined threshold is not exceeded.

23. A computer-readable medium having computer-executable instructions for performing the steps recited in claim 21.