Techniques for selective channel processing and data retention in an implantable medical device

• US 20060094970A1
• 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 8,224,431 B2
• Time in Patent Office: Days
• 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 5/318 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. An implanted device obtains data 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 processing physiologic data, comprising:

(A) dynamically selecting a first subset of physiologic channels from a plurality of physiologic channels based on a selection criterion at a first time value;

(B) retaining a first data associated with the first subset of physiologic channels;

(C) dynamically selecting a second subset of physiologic channels from the plurality of physiologic channels based on the selection criterion at a second time value; and

(D) retaining a second data associated with the second subset of physiologic channels.

2. The method of claim 1, wherein (B) comprises storing the first data in a first data record and wherein (D) comprises storing the second data in a second data record.

3. The method of claim 1, wherein (A) comprises:

(i) sorting the plurality of physiologic channels by relevancy; and

(ii) selecting those physiologic channels that have a highest relevancy.

4. The method of claim 3, wherein the relevancy is associated with a function, and wherein factors of the function are selected from the group consisting of an onset time, presence of a physiologic event, and a severity of the physiologic event.

5. The method of claim 1, wherein the first subset comprises a first physiologic channel from the plurality of physiologic channels, and wherein the first physiologic channel corresponds to a highest energy for the plurality of physiologic channels.

6. The method claim 5, wherein the first subset comprises another physiologic channel from the plurality of physiologic channels, and wherein the other physiologic channel corresponds to a next highest energy.

7. The method of claim 5, wherein the first subset comprises another physiologic channel from the plurality of physiologic channels, and wherein the other physiologic channel corresponds to a predetermined fraction of the highest energy.

8. The method of claim 1, further comprising:

(E) processing each physiologic channel of the plurality of physiologic channels with a window function.

9. The method of claim 8, wherein the first subset comprises a first physiologic channel from the plurality of physiologic channels, and wherein the first physiologic channel corresponds to a highest energy for the plurality of physiologic channels.

10. The method of claim 9, wherein the first subset comprises another physiologic channel from the plurality of physiologic channels, and wherein the other physiologic channel corresponds to a next highest energy.

11. The method of claim 1, wherein the first subset equals the second subset.

12. The method of claim 1, wherein (B) comprises storing the first data in a first data record and wherein (D) comprises storing the second data in the first data record.

13. The method of claim 12, wherein the first data comprises a composite data and further comprising:

(E) determining the composite data from sampled data for the first subset of physiologic channels.

14. The method of claim 13, wherein (E) comprises:

(i) determining a median value for the first subset of physiologic channels at an approximate time instance.

15. A medical device for processing physiologic data, comprising:

(A) a physiologic sensing component that obtains the physiologic data from a plurality of physiologic channels;

(B) a channel selection component that selects a subset of physiologic channels from the plurality of physiologic channels based on a selection criterion, wherein the selection criterion is associated with a characteristic of at least one of the plurality of physiologic channels; and

(C) a memory component that stores channel data corresponding to the subset of physiologic channels.

16. The medical device of claim 15, further comprising:

(D) an evaluation processor that obtains channel data from the channel selection component and processes the channel data for storage in the memory component.

17. The medical device of claim 16, wherein the processor utilizes the channel data for treatment associated with a physiologic event.

18. The medical device of claim 15, wherein the channel selection component comprises a channel processor, and wherein the channel processor is configured to perform:

(i) selecting the subset of physiologic channels from the plurality of physiologic channels based on the selection criterion at a time value;

(ii) retaining a first data associated with the subset of physiologic channels;

(iii) selecting another subset of physiologic channels from the plurality of physiologic channels based on the selection criterion at another time value; and

(iv) retaining a second data associated with the other subset of physiologic channels.

19. The medical device of claim 18, wherein the evaluation processor is configured to perform:

(v) storing data associated with the physiological signals in a priority data structure based on a priority index for the data.