SCHEME FOR OVERWRITING STORED PHYSIOLOGICAL DATA IN AN IMPLANTABLE MEDICAL DEVICE

• US 20080269811A1
• Filed: 04/26/2007
• Published: 10/30/2008
• Est. Priority Date: 04/26/2007
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Kleckner, Karen J., Krause, Paul G., Washburn, Traci K., Kolstad, Melinda A.
• Granted Patent: US 8,578,118 B2
• Time in Patent Office: Days
• US Class Current: 607/2
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• CPC Class Codes: A61B 5/287 Holders for multiple electrodes, e.g. electrode catheters for electrophysiological study [EPS]
• CPC Class Codes: A61N 1/3702 Physiological parameters A61N1/365 takes precedence; evoked response A61N1/371
• 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 40/67 for remote operation

Abstract

An implantable medical device and associated method store physiological data in response to detecting a physiological event. The medical device includes multiple first memory locations allocated to each of a number of physiological event types and a second single memory location allocated for storing entries of physiological signal data corresponding to each of the plurality of physiological event types.

Claims

1. A method for storing physiological data in an implantable medical device, comprising:

separately allocating a plurality of first memory locations to each of a plurality of physiological event types;

allocating a single second memory location to each of the plurality of physiological event types;

detecting a physiological event of an event type;

storing event data in a memory location of the plurality of first memory locations corresponding to the event type;

storing an entry of physiological signal data entry the second memory location; and

entering a location of the entry in an allocation table field linked to the stored event data in the memory location of the plurality of first memory locations.

2. The method of claim 1 wherein storing the entry comprises overwriting a previously stored physiological signal data entry in response to the single second memory location being full.

3. The method of claim 2 wherein storing the entry comprises applying a set of rules for identifying the previously stored physiological signal data entry to be overwritten.

4. The method of claim 3 wherein the rules for identifying correspond to the event type of the detected physiological event.

5. The method of claim 2 wherein overwriting the previously stored physiological signal data entry comprises identifying an oldest stored entry of physiological data of an event type for which at least a predetermined number of previously stored physiological data entries of the same event type as the oldest stored entry will remain if the oldest stored entry is overwritten.

6. The method of claim 2 wherein overwriting the previously stored physiological data entry further comprises overwriting a second previously stored entry of physiological data.

7. The method of claim 6 wherein overwriting the second previously stored entry comprises identifying a next oldest stored entry of physiological data of a next event type for which at least a predetermined number of previously stored entries of the next event type will remain if the next oldest stored entry is overwritten.

8. The method of claim 5 wherein identifying the oldest stored entry further comprises identifying the oldest stored entry of an event type corresponding to a previously defined low priority event type.

9. The method of claim 2 wherein overwriting the previously stored physiological signal data entry comprises identifying a previously stored entry of physiological data that has been previously uplinked to an external device.

10. The method of claim 1 wherein allocating the single second memory location comprises dividing the single second memory location into a plurality of memory segments and wherein storing the entry further comprises determining a number of the memory segments required for storing the entry, wherein the number corresponds to the event type of the detected physiological event.

11. The method of claim 10 wherein the number of required memory segments is a variable number.

12. The method of claim 1 further comprising determining a new event type during the detected physiological event and wherein storing event data comprises storing event data in a memory location of the plurality of first memory locations corresponding to the new event type in response to determining the new event type.

13. The method of claim 12 wherein allocating the single second memory location comprises dividing the single second memory location into a plurality of memory segments, and wherein storing the entry further comprises determining a number of the memory segments required for storing the entry, wherein the number corresponds to the event type of the detected physiological event, and further comprising re-determining the number of memory segments required for storing the entry in response to determining a new event type.

14. An implantable medical device configured to detect physiological events, comprising:

a plurality of first memory locations allocated to each of a plurality of physiological event types;

a second single memory location allocated for storing entries of physiological signal data corresponding to each of the plurality of physiological event types;

an allocation table forming a plurality of fields; and

a control module configured to store event data in a memory location of the plurality of first memory locations in response to detecting a physiological event of a first event type, the memory location of the plurality of first memory locations corresponding to the first event type, store an entry of physiological signal data in the second memory location, and enter a location of the stored entry of physiological signal data in an allocation table field linked to the stored event data in the memory location of the plurality of first memory locations.

15. The implantable medical device of claim 14 wherein storing the entry of physiological signal data comprises overwriting a previously stored entry of physiological signal data in response to the single second memory location being full.

16. The device of claim 15 wherein the control module applies a set of rules for identifying the previously stored physiological signal data entry to be overwritten.

17. The device of claim 16 wherein the rules for identifying correspond to the event type of the detected physiological event.

18. The implantable medical device of claim 15 wherein the control module identifies the previously stored entry as an oldest stored entry of an event type for which at least a predetermined number of previously stored entries of the same event type as the oldest stored entry will remain if the oldest stored entry is overwritten.

19. The implantable medical device of claim 15 wherein overwriting the previously stored entry further comprises overwriting a second previously stored entry.

20. The implantable medical device of claim 19 wherein the control module identifies the second previously stored entry as a next oldest stored entry of a next event type for which at least a predetermined number of previously stored entries of the next event type will remain if the next oldest stored entry is overwritten.

21. The implantable medical device of claim 18 wherein identifying the previously stored entry comprises identifying the oldest stored entry of an event type corresponding to a previously defined low priority event type.

22. The device of claim 15 wherein the control module identifies the previously stored entry as an entry that has been previously uplinked to an external device.

23. The device of claim 14 wherein the single second memory location comprises a plurality of memory segments, and wherein storing the entry comprises determining a number of the memory segments required for storing the entry, wherein the number corresponds to the event type of the detected physiological event.

24. The device of claim 23 wherein the number of required memory segments is a variable number.

25. The device of claim 14 wherein the control module determines a new event type during the detected physiological event and wherein storing event data comprises storing event data in a memory location of the plurality of first memory locations corresponding to the new event type in response to determining the new event type.

26. The device of claim 25 wherein the single second memory location comprises a plurality of memory segments and wherein storing the entry comprises determining a number of the memory segments required for storing the entry, wherein the number corresponds to the event type of the detected physiological event, the control module being configured to re-determine the number of memory segments required for storing the entry in response to determining a new event type.

27. A computer-readable medium having computer-executable instructions for performing a method comprising:

allocating a plurality of first memory locations to each of a plurality of physiological event types;

allocating a single second memory location for storing a plurality of entries of physiological signal data corresponding to each of the plurality of physiological event types;

detecting a physiological event of an event type;

storing event data in a memory location of the plurality of first memory locations corresponding to the event type;

storing an entry of physiological signal data in the second memory location; and

entering a location of the stored entry of physiological signal data in an allocation table field linked to the stored event data in the memory location of the plurality of first memory locations.

28. A memory structure implemented in an implantable medical device configured to detect physiological events, comprising:

a plurality of first memory locations allocated to each of a plurality of physiological event types;

a second single memory location allocated for storing entries of physiological signal data corresponding to each of the plurality of physiological event types; and

an allocation table for storing a location of an entry of physiological signal data stored in the second memory location linking the entry to data stored in a memory location of the plurality of first memory locations.