Prioritized dynamic memory allocation of arrhythmia episode detail collection

• US 6,589,187 B1
• Filed: 12/08/2000
• Issued: 07/08/2003
• Est. Priority Date: 12/08/2000
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Starkson, Ross O., Dirnberger, Denise
• Primary Examiner(s): Wolfe, Willis R.
• Application Number:
  US09/733,301
• Time in Patent Office: 942 Days
• Field of Search: 600/508, 600/509, 600/510, 600/515, 600/516, 600/517, 600/518, 600/519, 600/521, 600/523, 607/4, 607/5, 607/30, 607/32, 710/5, 710/20, 710/240, 710/244, 710/264, 710/268, 365/230.01, 365/230.08, 711/151, 711/170, 711/173
• US Class Current: 600/508
• CPC Class Codes: A61B 5/333 Recording apparatus specially adapted therefor
• CPC Class Codes: A61B 5/349 Detecting specific parameters of the electrocardiograph cycle
• CPC Class Codes: A61B 5/7264 Classification of physiological signals or data, e.g. using neural networks, statistical classifiers, expert systems or fuzzy systems neural networks per se G06N3/00; expert systems per se G06N5/00
• CPC Class Codes: A61N 1/3621 for treating or preventing abnormally high heart rate
• CPC Class Codes: A61N 1/3702 Physiological parameters A61N1/365 takes precedence; evoked response A61N1/371
• CPC Class Codes: G11C 7/1006 Data managing, e.g. manipulating data before writing or reading out, data bus switches or control circuits therefor

Abstract

A software system implemented in a medical device includes an allocation scheme for allocating storage of cardiac data. The software system enables storing cardiac data in a plurality of addressable locations. When all available locations within the plurality of addressable locations are full, a scratch location is assigned based on predetermined episode type priorities and characteristics. The priorities represent a graduated order based on the clinical significance of the cardiac episode under consideration. The characteristics provide classifications based on fastest rate, longest duration and last to occur care for each of the priorities.

Claims

1. A software system implemented in a medical device for allocating storage for cardiac data using a method of an allocation scheme, the method comprising:

storing said cardiac data in a plurality of addressable locations, said cardiac data being associated with various types of cardiac episodes;

determining whether all available locations within said plurality of addressable locations are full; and

assigning a scratch location within said plurality of addressable locations based on predetermined episode type priorities and characteristics.

2. The method of claim 1, wherein said priorities include a graduated order based on the clinical significance of said cardiac episodes.

3. The method of claim 1 wherein said characteristics include classifications based on fastest rate, longest duration and last to occur for each of said priorities.

4. The method of claim 3 wherein said cardiac episode represented by said characteristics for each of said priorities is immunized from scratch and ensured allocation space.

5. The method of claim 4 wherein the allocation scheme includes a process of assigning storage for each of said priorities that is immunized while ensuring the availability of at least one location for sharing data for the next cardiac episode.

6. An apparatus in an implantable cardiac device, comprising:

an episode summary log memory adapted to store a plurality of entries, each entry correlating to a cardiac event episode; and

an episode detail memory adapted to store a plurality of cardiac data, each set of cardiac data correlating to a particular cardiac event episode, wherein at least one

an episode detail memory adapted to store a plurality of cardiac data, each set of cardiac data correlating to a particular cardiac event episode, wherein at least one entry in the episode summary log memory is adapted to include a pointer to a corresponding at least one set of cardiac data in the episode detail memory.

7. The apparatus of claim 6, wherein each of the plurality of entries in the episode summary log memory includes a date and time when a cardiac event episode occurred, a duration of the cardiac event episode, and a maximum heart rate detected during the cardiac event episode.

8. The apparatus of claim 6, wherein each of the plurality of sets of cardiac data includes cardiac data and marker data.

9. The apparatus of claim 6, wherein the episode summary log memory is at least a portion of a random access memory.

10. The apparatus of claim 6, wherein the episode detail memory is at least a portion of a random access memory.

11. The apparatus of claim 6, wherein the episode summary log memory is adapted to store approximately 100 entries.

12. The apparatus of claim 11, wherein the episode detail memory is adapted to store a maximum of sixteen sets of EGM data.

14. The apparatus of claim 6, wherein the episode detail memory is adapted to store a maximum of sixteen sets of cardiac data.

15. The apparatus of claim 6, wherein the episode detail memory is adapted to store up to fifteen sets of EGM data, and wherein the apparatus further comprises a scratch buffer in the episode detail memory adapted to receive a set of EGM data correlating to a most-recently-detected cardiac event episode.

17. The apparatus of claim 6, further comprising a plurality of significant event pointers, each significant event pointer adapted to identify a set of EGM data in the episode detail memory.

18. The apparatus of claim 17, further comprising a scratch buffer pointer adapted to identify a location in the episode detail memory where a set of EGM data associated with a next-occurring cardiac event episode may be recorded.

13. An apparatus in an implantable cardiac device, comprising:

an episode summary log memory adapted to store a plurality of entries, each entry correlating to a cardiac event episode; and

an episode detail memory adapted to store a plurality of cardiac data, each set of cardiac data correlating to a particular cardiac event episode,

wherein at least one entry in the episode summary log memory is adapted to include a pointer to a corresponding at least one set of cardiac data in the episode detail memory;

wherein the episode summary log memory is adapted to store approximately 100 entries;

wherein, the episode detail memory is adapted to store up to fifteen sets of EGM data; and

wherein the apparatus further comprises a scratch buffer in the episode detail memory adapted to receive a set of cardiac data correlating to a most-recently-detected cardiac event episode.

16. The apparatus of claim 13, wherein the pointer in the at least one entry in the episode summary log memory is adapted to be invalidated in response to receipt by the scratch buffer of a set of EGM data.