Techniques for user-activated data retention in an implantable medical device

• US 20060094972A1
• Filed: 11/02/2005
• Published: 05/04/2006
• Est. Priority Date: 11/02/2004
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Drew, Touby A.
• Granted Patent: US 8,024,029 B2
• Time in Patent Office: Days
• US Class Current: 600/523
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• CPC Class Codes: A61B 5/113 occurring during breathing
• CPC Class Codes: A61B 5/335 using integrated circuit memory devices
• 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 5/384 Recording apparatus or displays specially adapted therefor
• CPC Class Codes: A61B 5/4094 Diagnosing or monitoring seizure diseases, e.g. epilepsy
• CPC Class Codes: A61B 5/7232 involving compression of the physiological signal, e.g. to extend the signal recording period
• CPC Class Codes: A61N 1/36082 Cognitive or psychiatric applications, e.g. dementia or Alzheimer's disease
• CPC Class Codes: A61N 1/3702 Physiological parameters A61N1/365 takes precedence; evoked response A61N1/371
• CPC Class Codes: A61N 1/37252 Details of algorithms or data aspects of communication system, e.g. handshaking, transmitting specific data or segmenting data
• CPC Class Codes: G16H 40/63 for local operation

Abstract

Apparatus for storing data records associated with a medical monitoring event in a data structure. Upon indication by a patient of a possible manifestation of a neurological event, the implanted device obtains and stores data in the data record in a first data structure that is age-based. Before an oldest data record is lost, the oldest data record may be stored in a second data structure that is priority index-based. The priority index may be determined by a severity level and may be further determined by associated factors. The implanted device may organize, off-load, report, and/or display a plurality of data records based on an associated priority index. Additionally, the implanted device may select a subset or composite of physiologic channels from the available physiologic channels based on a selection criterion.

Claims

1. A method for retaining physiologic data in an implantable medical device comprising:

(A) receiving an external indication to trigger loop recording;

(B) receiving a new data record associated with a physiologic condition of a patient;

(C) determining a new priority index of the new data record;

(D) replacing at least a portion of an old data record with the new data record in a first data structure; and

(E) if an old priority index associated with the old data record exceeds a threshold criterion, storing at least a portion of the old data record in a second data structure.

2. The method of claim 1, wherein (C) comprises assigning a high priority index of the new data record if a detection algorithm does not detect a possible occurrence of a neurological event.

3. The method of claim 1, wherein (A) comprises receiving a signal external to the implantable medical device indicating an occurrence of a neurological event.

4. The method of claim 3, wherein (A) comprises receiving the external signal from a patient or caregiver.

5. The method of claim 1, wherein the new data record is associated with a sensed signal selected from the group consisting of an EEG signal, and ECG signal, and a respiratory signal.

6. A medical device for monitoring physiologic activity, comprising:

(A) a monitoring element that obtains at least one physiological signal;

(B) an event detection component for determining possible occurrence of a neurological event based on the physiological signal;

(C) a memory component that stores the physiological signal as a plurality of data records, each data record representing information about an associated event, the memory component comprising a first data structure and a second data structure; and

(D) a processing component interfacing with the monitoring element and the memory component and configured to;

(i) replace at least a portion of an existing data record in the first data structure with a new data record;

(ii) determine an associated priority index of the existing data record; and

(iii) store in the second data structure at least the portion of the existing data record that was replaced from the first data structure if the associated priority index of the existing data record exceeds a threshold criterion.

7. The medical device of claim 6, wherein the processing component is configured to assigns a high priority index to the new data record if the event detection component determines possible occurrence of the neurological event based on the physiological signal.

8. The medical device of claim 6, further comprising:

(E) an external device,

wherein the processing component is configured to assigns a high priority index to the new data record if the external device initiates recording of the new data record.

9. The medical device of claim 8, wherein the external device is an external activator device.

10. The medical device of claim 8, wherein the external device is an external wearable device.

11. The medical device of claim 10, wherein the external wearable device is selected from the group consisting of a wearable patch, a wristwatch, and a wearable computing device.

12. The medical device of claim 6, further comprising:

(E) an external device,

wherein the processing component is configured to assigns a higher priority index to the new data record if the external device initiates recording of the new data record but the event detection component has not determined the possible occurrence of the neurological event.