Techniques for data retention upon detection of an event in an implantable medical device

• US 20060094971A1
• 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 8,108,033 B2
• Time in Patent Office: Days
• US Class Current: 600/513
• CPC Class Codes: A61B 5/0006 ECG or EEG signals
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• CPC Class Codes: A61B 5/02055 Simultaneously evaluating both cardiovascular condition and temperature
• CPC Class Codes: A61B 5/021 Measuring pressure in heart or blood vessels A61B5/0205 takes precedence
• CPC Class Codes: A61B 5/024 Detecting, measuring or recording pulse rate or heart rate A61B5/0205, A61B5/021 take precedence
• CPC Class Codes: A61B 5/031 Intracranial pressure
• CPC Class Codes: A61B 5/0816 Measuring devices for examining respiratory frequency measuring frequency of electric signals G01R23/00
• CPC Class Codes: A61B 5/1118 Determining activity level
• CPC Class Codes: A61B 5/165 Evaluating the state of mind, e.g. depression, anxiety
• CPC Class Codes: A61B 5/24 Detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof
• CPC Class Codes: A61B 5/316 Modalities, i.e. specific diagnostic methods
• CPC Class Codes: A61B 5/318 Heart-related electrical modalities, e.g. electrocardiography [ECG]
• CPC Class Codes: A61B 5/369 Electroencephalography [EEG] devices for psychotechnics A61B5/16
• CPC Class Codes: A61B 5/4082 Diagnosing or monitoring movement diseases, e.g. Parkinson, Huntington or Tourette
• CPC Class Codes: A61B 5/4094 Diagnosing or monitoring seizure diseases, e.g. epilepsy
• CPC Class Codes: A61B 5/686 Permanently implanted devices, e.g. pacemakers, other stimulators, biochips A61B5/6861 takes precedence
• CPC Class Codes: A61B 5/7232 involving compression of the physiological signal, e.g. to extend the signal recording period
• 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 1/36132 using patient feedback
• CPC Class Codes: A61N 1/3614 based on impedance measurement
• 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 1/3702 : 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: A61N 1/37282 : characterised by communication with experts in remote locations using a network
• CPC Class Codes: G06F 16/2272 : Management thereof
• CPC Class Codes: G16H 10/60 : for patient-specific data, e.g. for electronic patient records
• CPC Class Codes: G16H 10/65 : stored on portable record carriers, e.g. on smartcards, RFID tags or CD
• CPC Class Codes: G16H 20/30 : relating to physical therapies or activities, e.g. physiotherapy, acupressure or exercising
• CPC Class Codes: G16H 40/63 : for local operation
• CPC Class Codes: G16H 40/67 : for remote operation

Abstract

Methods and apparatus for storing data records associated with a medical monitoring event in a data structure. Upon detection of a possible occurrence of a physiological event by one group of monitoring elements, an implanted device records data received from another group of monitoring elements. The implanted device obtains and stores the 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. An implantable medical device comprising:

(A) a first monitoring element that receives a first signal set associated with a brain activity;

(B) a second monitoring element that receives a second signal set associated with a second type of physiologic activity;

(C) a processing component capable of detecting a possible occurrence of a physiological event based on the first or second signal set; and

(D) a memory component that stores at least a portion of the first signal set and at least a portion of the second signal sets upon detection of the possible physiological event.

2. The implantable medical device of claim 1, wherein the processing component is capable of detecting a possible occurrence of a physiological event based on the first signal set.

3. The implantable medical device of claim 1, wherein the physiological event is a seizure.

4. The implantable medical device of claim 1, wherein the physiological activity is a heart activity.

5. The implantable medical device of claim 4, wherein the heart activity is a heart arrhythmia.

6. The implantable medical device of claim 1, wherein the physiological activity is a respiratory activity.

7. The implantable medical device of claim 1, wherein the memory component comprises:

(i) a first data structure that stores a plurality of data records relating to at least the second signal set upon detection by the processing component of a possible neurological event, each data record representing information about an associated event; and

(ii) a second data structure that stores at least a portion of a first data record from the first data structure if an associated priority index of the first data record exceeds a threshold criterion.

8. The implantable medical device of claim 1, wherein the first data structure is capable of replacing at least a portion of the first data record with a new data record.

9. The implantable medical device of claim 1, wherein the first signal set is an EEG signal set and the second signal set is an ECG signal set.

10. The implantable medical device of claim 1, wherein the second signal set is selected from the group consisting of an EEG signal set, an ECG signal set, and a respiratory signal set.

11. The implanted device of claim 1, wherein the second data structure stores the first data record only if the priority index of the first data record is greater than an other priority index of an other data record in the second data structure.

12. The implanted device of claim 1, wherein the processing component determines an associated priority index from an associated severity level of the physiological event.

13. The implanted device of claim 1, further comprising:

(E) a reporting module that selects selected data records from the first data structure and from the priority data structure and that reports data associated with the selected data records.

14. The implanted device of claim 13, wherein the reporting module selects the selected data records based on an associated priority index of the selected data record.

15. The implanted device of claim 1, wherein the physiological event is selected from the group consisting of a cardiac event, a neurological event, a pulmonary event, and a telemetry event.

16. The implanted device of claim 1, wherein the first data structure comprises a priority queue.

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

(A) receiving a first signal set associated with a physiologic condition;

(B) receiving a second signal set;

(C) detecting a possible occurrence of a neurological event based on at least the first signal set;

(D) storing in a first data structure a plurality of data records relating to at least the second signal set upon detection of the possible neurological event, each data record representing information about an associated event; and

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

18. The method of claim 17, wherein (D) comprises replacing at least a portion of the first data record with a new data record.

19. The method of claim 17, wherein the first signal set is an EEG signal set and the second signal set is an ECG signal set.

20. The method of claim 17, wherein the first signal set and the second signal set are each selected from the group consisting of an EEG signal set and a respiratory signal set.

21. The method of claim 17, wherein the first signal set and the second signal set are each selected from the group consisting of an EEG signal set, an ECG signal set, and a respiratory signal set.

22. The method of claim 17, wherein (E) is performed only if the priority index of the first data record is greater than an other priority index of an other data record in the second data structure.

23. The method of claim 17, further comprising:

(F) selecting data records from the first data structure and from the priority data structure and reporting data associated with the selected data records.

24. The method of claim 23, wherein (F) comprises selecting the selected data records based on the associated priority index of the selected data record.