CLOSED LOOP PARAMETER ADJUSTMENT FOR SENSOR MODULES OF AN IMPLANTABLE MEDICAL DEVICE

• US 20100105997A1
• Filed: 01/29/2009
• Published: 04/29/2010
• Est. Priority Date: 10/29/2008
• Status: Abandoned Application

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Davis, Timothy, Reinke, James D., Patil, Kaustubh R., Ecker, Robert Michael, Hamilton, John Robert
• Application Number:
  US12/361,990
• Publication Number:
  US 20100105997A1
• Time in Patent Office: Days
• US Class Current: 600/334
• CPC Class Codes: A61B 5/02028 Determining haemodynamic parameters not otherwise provided for, e.g. cardiac contractility or left ventricular ejection fraction
• CPC Class Codes: A61B 5/14542 for measuring blood gases A61B5/14551 takes precedence
• CPC Class Codes: A61B 5/1459 invasive, e.g. introduced into the body by a catheter A61B5/1464 takes precedence
• CPC Class Codes: A61B 5/7203 for noise prevention, reduction or removal
• CPC Class Codes: A61N 1/36585 controlled by two or more physical parameters

Abstract

In general, the invention is directed toward an implantable medical device that includes a controller and a plurality of sensor modules. The controller may control the sensor modules to perform one or more sensor actions in order to facilitate a measurement. The sensor modules may store one or more operational parameters that control various aspects of the sensor actions performed by the sensor modules. The controller may automatically adjust one or more of the operational parameters based on results received from previous measurements in order to provide closed loop parameter adjustment of the operational parameters associated with the sensor modules. The controller may communicate with the sensor modules via a common bus. Example measurements include tissue perfusion measurements, blood oxygen sensing measurements, sonomicrometry measurements, and pressure measurements.

Claims

1. An implantable medical device comprising:

a first sensor module configured to perform a first sensor action;

a second sensor module configured to perform a second sensor action;

a controller configured to obtain results for a measurement, and automatically adjust an operational parameter associated with at least one of the first sensor module and the second sensor module based on the results for the measurement such that results for subsequent measurements are within a target range for further signal processing, wherein the results for the measurement are based upon performance of the first sensor action and upon performance of the second sensor action, and wherein the first sensor module, the second sensor module, and the controller are coupled to a common bus.

2. The implantable medical device of claim 1, wherein the controller is further configured to automatically adjust the operational parameter based on the results for the measurement such that results for subsequent measurements have a magnitude within a target range for analog-to-digital conversion.

3. The implantable medical device of claim 1, wherein the controller is further configured to automatically adjust the operational parameter based on the results for the measurement such that results for subsequent measurements have an amplitude variation within a target range for analog-to-digital conversion.

4. The implantable medical device of claim 1, wherein the controller is further configured to obtain results for the measurement from the second sensor module, and automatically adjust an operational parameter associated with the first sensor module based on the results for the measurement.

5. The implantable medical device of claim 4, wherein the first sensor module is configured to emit light according to an amount of intensity controlled by the operational parameter associated with the first sensor module.

6. The implantable medical device of claim 4, wherein the first sensor module comprises one or more light emitting diodes (LEDs) configured to emit light, and the operational parameter associated with the first sensor module is an LED supply current parameter that controls the amount of current supplied to the LEDs.

7. The implantable medical device of claim 1, wherein the controller is further configured to obtain results for the measurement from the second sensor module, and automatically adjust an operational parameter associated with the second sensor module based on the results for the measurement.

8. The implantable medical device of claim 7, wherein the second sensor module is configured to detect light for an amount of time controlled by the operational parameter.

9. The implantable medical device of claim 7, wherein the second sensor module comprises a photo-integrator configured to integrate an amount of received light, and the operational parameter associated with the second sensor module is a photo-integration time parameter that controls an amount of time that the photo-integrator integrates the amount of received light for a measurement.

10. The implantable medical device of claim 7, wherein the second sensor module is configured to amplify a measured amount of received light according to an amount of gain controlled by the operational parameter associated with the second sensor module.

11. The implantable medical device of claim 7, wherein the second sensor module comprises a photo-integrator configured to amplify an amount of received light, and the operational parameter associated with the second sensor module is a photo-integration gain parameter that controls an amount of amplification of the received light.

12. The implantable medical device of claim 1, wherein the controller is further configured to periodically perform automatic adjustment of the operational parameter based on the results for the measurement such that results for subsequent measurements are within a target range for further signal processing.

13. The implantable medical device of claim 1, wherein the controller is further configured to automatically adjust a first operational parameter within at least one of the first sensor module and the second sensor module based on results for a first type of light measurement such that results for subsequent first type of light measurements are within a target range for further signal processing, and after automatically adjusting the first operational parameter, the controller is further configured to automatically adjust a second operational parameter within at least one of the first sensor module and the second sensor module based on results for a second type of light measurement such that results for subsequent second type of light measurements are within a target range for further signal processing.

14. The implantable medical device of claim 13, wherein the first type of light measurement and the second type of light measurement are each selected from the group consisting of a red light measurement, an isobestic light measurement, an infrared light measurement, and an ambient light measurement.

15. The implantable medical device of claim 14, wherein the first type of light measurement is selected based on a type of light that is least transmissive through tissue.

16. The implantable medical device of claim 1, wherein the controller is further configured to adjust a first operational parameter associated with the first sensor module based on the results for the measurement, obtain results for a subsequent measurement, determine if results for the subsequent measurement are within the target range, maintain the first operational parameter for additional measurements if the results for the subsequent measurement are within the target range, determine if the first operational parameter is at a minimum or a maximum of a target range for the first operational parameter if the results for the subsequent measurement are not within the target range, adjust a second operational parameter associated with the second sensor module based on results for the subsequent measurement if the first operational parameter is at the minimum or the maximum of the target range for the first operational parameter, and adjust the first operational parameter based on results for the subsequent measurement if the first operational parameter is not at the minimum or the maximum of the target range for the first operational parameter.

17. The implantable medical device of claim 16, wherein the first operational parameter is a light emitting diode (LED) supply current parameter associated with the first sensor module, and wherein the second operational parameter is one of an integration gain parameter associated with the second sensor module or an integration time parameter associated with the second sensor module.

18. The implantable medical device of claim 1, wherein the measurement is one of a tissue perfusion measurement, an oxygen sensing measurement, a sonomicrometry measurement, or a pressure measurement.

19. A method comprising:

obtaining results for a measurement with a controller of an implantable medical device, wherein the results for the measurement are based upon performance of a first sensor action by a first sensor module of the implantable medical device and upon performance of a second sensor action by a second sensor module of the implantable medical device, and wherein the first sensor module, the second sensor module, and the controller are coupled to a common bus; and

automatically adjusting, with the controller, an operational parameter associated with at least one of the first sensor module and the second sensor module based on the results for the measurement such that results for subsequent measurements are within a target range for further signal processing.

20. An implantable medical device comprising:

means for performing a first sensor action;

means for performing a second sensor action;

means for obtaining results for a measurement, wherein the results for the measurement are based upon performance of the first sensor action and upon performance of the second sensor action; and

means for automatically adjusting an operational parameter associated with at least one of the first sensor module and the second sensor module based on the results for the measurement such that results for subsequent measurements are within a target range for further signal processing, wherein the means for performing the first sensor action, the means for performing the second sensor action, the means for obtaining results for the measurement, and the means for automatically adjusting the operational parameter are coupled to a common bus.