System and Method for Providing Fault Tolerant Processing in an Implantable Medical Device

• US 20100088539A1
• Filed: 09/28/2009
• Published: 04/08/2010
• Est. Priority Date: 10/01/2008
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Sowder, Conrad L., Stubbs, Scott R., Hoyme, Kenneth P., Linder, William J., Elliott, Lynn S., Doshi, Hiten J.
• Granted Patent: US 8,347,149 B2
• Time in Patent Office: Days
• US Class Current: 714/3
• CPC Class Codes: G06F 11/0715 in a system implementing multitasking multitasking per se G06F9/46
• CPC Class Codes: G06F 11/0751 Error or fault detection not based on redundancy power supply failures G06F1/30; network fault management H04L41/06
• CPC Class Codes: G06F 11/0757 by exceeding a time limit, i.e. time-out, e.g. watchdogs
• CPC Class Codes: G06F 11/0793 Remedial or corrective actions recovery from an exception in an instruction pipeline G06F9/3861; by retry G06F11/1402; for recovering from a failure of a protocol instance or entity H04L69/40

Abstract

Embodiments herein generally relate to implantable medical devices and, specifically, to a system and method for providing fault tolerant processing in an implantable medical device. In an embodiment a system for providing fault tolerant processing in an implantable medical device is provided. The system can include an implantable medical device comprising a processor and memory store configured to execute a plurality of threads, temporal and spatial constraints assigned to one or more of the threads, and a kernel. The kernel can include a scheduler and a thread monitor configured to monitor execution of threads against the temporal and spatial constraints, and further configured to issue a response upon violation of either of the constraints by one of the plurality of threads. In an embodiment a method for providing fault tolerant processing in an implantable medical device is provided. Other embodiments are also included herein.

Claims

1. A system for providing fault tolerant processing in an implantable medical device, comprising:

an implantable medical device comprising a processor and memory store, the processor and memory store configured to execute a plurality of threads;

temporal and spatial constraints assigned to one or more of the threads; and

a kernel, comprising

a scheduler configured to divide processing time among the plurality of threads; and

a thread monitor configured to monitor execution of threads against the temporal and spatial constraints, the spatial constraints comprising a unique identifier assigned for each thread prior to execution, wherein the unique identifier for each thread that completes is checked against the unique identifier previously assigned, and the thread monitor further configured to issue a response upon violation of either of the constraints by one of the plurality of threads.

2. The system of claim 1, wherein the temporal constraints comprise a maximum allowable execution time for each of the plurality of threads.

3. The system of claim 2, wherein the thread monitor further comprises a timer configured to expire at the maximum allowable execution time for execution of each of the plurality of threads.

4. The system of claim 1, wherein the kernel further comprises an exception handler configured to take corrective action when a response is issued.

5. The system of claim 1, further comprising a watch dog timer, the kernel configured to service the watch dog timer using the lowest priority thread.

6. The system of claim 1, wherein the constraints are assigned to one or more threads at compile time.

7. The system of claim 1, wherein the constraints are uniquely assigned to each specific thread.

8. The system of claim 1, wherein the constraints are uniquely assigned to each specific class of threads.

9. The system of claim 1, wherein the implantable medical device is selected from the group comprising a pacemaker, implantable cardioverter-defibrillator, biventricular pacemaker, implantable sensor, neural stimulator, and implantable monitor.

10. A method for providing fault tolerant processing in an implantable medical device, comprising:

providing a processor and memory store in an implantable medical device that are configured to execute a plurality of threads;

defining temporal and spatial constraints for one or more of the plurality of threads;

dividing processing time between the plurality of threads;

monitoring thread execution and memory usage of each execution thread respectively against the temporal and spatial constraints; and

issuing a response upon violation of either of the constraints by one such execution thread.

11. The method of claim 10, further comprising:

timing each execution thread; and

flagging thread execution upon expiry of the timer absent normal completion of the execution thread.

12. The method of claim 10, further comprising:

assigning a unique identifier to each thread;

verifying the unique identifier upon normal completion of the thread; and

flagging an error if the thread identifier fails to match.

13. The method of claim 10, further comprising:

taking corrective action upon fault detection; and

recovering operation of the implantable medical device.

14. The method of claim 10, further comprising:

providing a watch dog timer, the kernel configured to service the watch dog timer using the lowest priority thread.

15. The method of claim 10, further comprising:

specifying the constraints for one or more threads at compile time.

16. The method of claim 10, further comprising assigning the constraints to each specific thread.

17. The method of claim 10, further comprising assigning the constraints to a class of threads.

18. The method of claim 10, wherein the implantable medical device is selected from the group consisting of:

a pacemaker, implantable cardioverter-defibrillator, biventricular pacemaker, implantable sensor, neural stimulator, and implantable monitor.