SYSTEM AND METHOD FOR PROVIDING FAULT RESILIENT PROCESSING IN AN IMPLANTABLE MEDICAL DEVICE

• US 20090254915A1
• Filed: 04/03/2009
• Published: 10/08/2009
• Est. Priority Date: 04/04/2008
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Stubbs, Scott R., Hoyme, Kenneth P.
• Granted Patent: US 8,402,467 B2
• Time in Patent Office: Days
• US Class Current: 718/103
• CPC Class Codes: G06F 11/004 Error avoidance G06F11/07 and subgroups take precedence
• CPC Class Codes: G06F 9/4881 Scheduling strategies for dispatcher, e.g. round robin, multi-level priority queues
• CPC Class Codes: G06F 9/5016 the resource being the memory

Abstract

A system and method for providing fault resilient processing in an implantable medical device is provided. A processor and memory store are provided in an implantable medical device. Separate times on the processor are scheduled to a plurality of processes. Separate memory spaces in the memory store are managed by exclusively associating one such separate memory space with each of the processes. Data is selectively validated prior to exchange from one of the processes to another of the processes during execution in the separate processor times.

Claims

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

an implantable medical device comprising a processor and memory store; and

a high integrity kernel configured to execute on the processor and evaluate a priority of execution for each partitioned process, wherein processes necessary for therapy output are assigned the highest priority of execution amongst partitioned processes, the high integrity kernel comprising;

a scheduler configured to schedule separate times on the processor to a plurality of processes;

a data loader configured to manage separate memory spaces in the memory store by exclusively associating one such separate memory space with each of the processes; and

a data validator configured to selectively validate data prior to exchange from one of the processes to another of the processes during execution in the separate processor times based on the priority of execution for each process.

2. The system of claim 1, wherein processes with higher priorities of execution are scheduled before other processes.

3. The system of claim 1, wherein processes necessary for diagnosing a patient receive the second highest priority of execution amongst partitioned processes, processes necessary for system telemetry receive the third highest priority of execution amongst partitioned processes, and processes necessary for device diagnostics receive the fourth highest priority of execution amongst partitioned processes.

4. The system of claim 1, wherein selectively validating data comprising increasing a level of rigor in the validating of the data for processes having a higher priority of execution.

5. The system of claim 1, wherein the high integrity kernel allocates the separate processor times through process partitions, further comprising:

a fault resolver configured to resolve runtime faults within one such process partition, comprising at least one of terminating the process partition, ignoring the process partition, restarting the process partition completely, restarting the process partition in a degraded mode, starting an alternate process partition, and transferring functionality of the process partition to a different process partition.

6. The system of claim 1, further comprising:

discrete blocks of the memory space assigned into each such separate memory space, wherein exclusive write control is exercised over memory locations within each such discrete block of the memory space.

7. The system of claim 1, further comprising:

a nominal quantum of processor time determined for the processes, wherein at least the nominal quantum is allotted to each of the processes in the separate processor times.

8. The system of claim 1, wherein access to the one such separate memory space is restricted to the associated process.

9. The system of claim 1, further comprising at least one of:

a cooperative scheduler configured to block the execution of one such process upon an occurrence of waiting for an event or voluntary relinquishment of the processor; and

a preemptive scheduler configured to block the execution of one such process upon expiration of a quantum of processor time.

10. The system of claim 1, wherein the implantable medical device is an active implantable medical device.

11. The system of claim 1, wherein the implantable medical device is selected from the group comprising a pacemaker, implantable cardioverter-defibrillator, cardiac resynchronization device, neuromodulation device, implantable sensor, and implantable monitor.

12. A system for partitioning an implantable medical device for fault resilient execution, comprising:

an implantable medical device, comprising;

a uniprocessor; and

a memory store interconnected to the uniprocessor and comprising addressable memory locations;

a time partition configured to operationally separate a plurality of processes, comprising;

a criticality of function provided by each process; and

a scheduler configured to schedule separate times for execution on the uniprocessor to the processes in order of the criticality of function; and

a space partition configured to physically separate the plurality of processes, comprising;

discrete blocks of the addressable memory locations of the memory store associated to each of the processes; and

a data validator configured to selectively validate data sent from one of the processes to another of the processes during execution on the uniprocessor.

13. The system of claim 12, further comprising:

a prioritization module configured to prioritize the processes by the criticality of function, wherein those processes with higher criticality of function receive the higher priorities of execution;

a cooperative scheduler configured to cooperatively allot the separate execution times to those of the processes having the higher priorities of execution; and

a preemptive scheduler configured to preemptively allot the separate execution times to those other of the processes.

14. The system of claim 12, further comprising:

a prioritization module configured to prioritize the processes by the criticality of function, wherein a level of rigor in the validating of the data is increased for those of the processes having the higher criticality of function, and a level of rigor in the validating of the data is decreased for those other of the processes.

15. The system of claim 12, further comprising:

a process identifier assigned to each of the processes during the separate execution times, wherein each process identifier is associated with the one such separate memory space of the assigned process.

16. The system of claim 12, wherein the implantable medical device is selected from the group comprising a pacemaker, implantable cardioverter-defibrillator, biventricular pacemaker, implantable sensor, and implantable monitor.

17. A method for partitioning an implantable medical device for fault resilient execution, comprising:

providing a uniprocessor and interconnected memory store comprising addressable memory locations in an implantable medical device;

operationally separating a plurality of processes, comprising;

evaluating a criticality of function provided by each process; and

scheduling separate times for execution on the uniprocessor to the processes in order of the criticality of function; and

physically separating the plurality of processes, comprising;

associating discrete blocks of the addressable memory locations of the memory store to each of the processes; and

selectively validating data sent from one of the processes to another of the processes during execution on the uniprocessor.

18. The method of claim 17, further comprising:

prioritizing the processes by the criticality of function, wherein those processes with higher criticality of function receive the higher priorities of execution;

cooperatively allotting the separate execution times to those of the processes having the higher priorities of execution; and

preemptively allotting the separate execution times to those other of the processes.

19. The method of claim 17, further comprising:

prioritizing the processes by the criticality of function; and

increasing a level of rigor in the validating of the data for those of the processes having the higher criticality of function; and

decreasing a level of rigor in the validating of the data for those other of the processes.

20. The method of claim 17, further comprising:

assigning a process identifier to each of the processes during the separate execution times; and

associating each process identifier with the one such separate memory space of the assigned process.

21. The method of claim 17, wherein the implantable medical device is selected from the group comprising a pacemaker, implantable cardioverter-defibrillator, biventricular pacemaker, implantable sensor, and implantable monitor.