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

• US 8,108,033 B2
• Filed: 11/02/2005
• Issued: 01/31/2012
• 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., Giftakis, Jonathon E., Carlson, David L., Panken, Eric J., Werder, Jonathan C., Graves, Nina M.
• Primary Examiner(s): Layno, Carl H
• Assistant Examiner(s): Stice, Paula J
• Application Number:
  US11/264,974
• Publication Number:
  US 20060094971A1
• Time in Patent Office: 2,281 Days
• Field of Search: 600/509, 600/523, 600/544, 600513-518, 607/30, 607/59, 607/128, 705 2- 3
• US Class Current: 600/509
• 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 5/33 specially adapted for cooperation with other devices
• CPC Class Codes: A61B 5/37 Intracranial electroencephalography [IC-EEG], e.g. electrocorticography [ECoG]
• 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. 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, by the implantable medical device, a possible occurrence of a neurological event based on at least the first signal set;

(D) storing in a first data structure comprising memory a data record relating to the second signal set, the data record representing information about the neurological event, the first data structure being an age-based circular buffer wherein older data stored in the first data structure, including the data record, are replaced with new data records as additional data are received;

(E) determining a priority index for the data record based on a severity of the neurological event; and

(F) transferring the data record from the first data structure for storage in a second data structure comprising memory upon determining that the priority index of the data record is greater than another priority index of another data record in the second data structure, the second data structure distinct from the first data structure.

2. The method of claim 1, wherein (F) comprises replacing data in the second data structure with the data record.

3. The method of claim 1, wherein the first signal set is an EEG signal set and the second signal set is an ECG signal set.

4. The method of claim 1, 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.

5. The method of claim 1, 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.

6. The method of claim 1, further comprising:

(G) selecting data records from the first data structure and from the second data structure and reporting data associated with the selected data records.

7. The method of claim 6, wherein (G) comprises selecting the selected data records based on the associated priority index of the selected data record.

8. The method of claim 1, wherein (F) is performed in response to determining that the first data structure is full.

9. An apparatus comprising:

a processor; and

a memory storing computer readable instructions that, when executed, cause the apparatus at least to perform operations 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 comprising memory a data record relating to the second signal set, the data record representing information about the neurological event, the first data structure being an age-based circular buffer wherein older data stored in the first data structure, including the data record, are replaced with new data records as additional data are received;

(E) determining a priority index for the data record based on a severity of the neurological event; and

(F) transferring the data record from the first data structure for storage in a second data structure comprising memory upon determining that the priority index of the data record is greater than another priority index of another data record in the second data structure, the second data structure distinct from the first data structure.

10. The apparatus of claim 9, wherein (F) comprises replacing data in the second data structure with the data record.

11. The apparatus of claim 9, wherein the first signal set is an EEG signal set and the second signal set is an ECG signal set.

12. The apparatus of claim 9, 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.

13. The apparatus of claim 9, further comprising:

(G) selecting data records from the first data structure and from the second data structure and reporting data associated with the selected data records.

14. The apparatus of claim 13, wherein (G) comprises selecting the selected data records based on the associated priority index of the selected data record.

15. The apparatus of claim 9, wherein (F) is performed in response to determining that the first data structure is full.

16. A method comprising:

(A) storing in a first data structure a plurality of data records that respectively represent information about associated neurological events, the first data structure being an age-based circular buffer wherein older data of the plurality of data records stored in the first data structure is replaced with newer data records of the plurality of data records as data is received;

(B) processing, by an implantable medical device, a signal to detect a possible occurrence of a neurological event;

(C) determining a priority index for a first data record of the plurality of data records based on a severity of the neurological event; and

(D) transferring the first data record from the first data structure for storage in a second data structure upon determining that the priority index of the first data record exceeds a threshold criterion, the first data structure being a memory, the second data structure being a memory, the second data structure distinct from the first data structure.

17. The method of claim 16, wherein (D)is performed in response to determining that the first data structure is full.

18. An apparatus comprising:

a processor; and

a memory storing computer readable instructions that, when executed by the processor, cause the apparatus at least to perform operations comprising;

(A) storing in a first data structure a plurality of data records that respectively represent information about associated neurological events, the first data structure being an age-based circular buffer wherein older data of the plurality of data records stored in the first data structure is replaced with newer data records of the plurality of data records as data is received;

(B) processing a signal to detect a possible occurrence of a neurological event;

(C) determining a priority index for a first data record of the plurality of data records based on a severity of the neurological event, the first data record representing information about the neurological event; and

(D) transferring the first data record from the first data structure for storage in a second data structure upon determining that the priority index of the first data record exceeds another priority index of another data record of the plurality of data records stored in the second data structure, the first data structure and the second data structure comprising memory and the second data structure being distinct from the first data structure.