Techniques for electronically assessing electrode condition and peri-electrode tissue conductivity change pre- and post-MRI

• US 8,825,172 B2
• Filed: 07/17/2013
• Issued: 09/02/2014
• Est. Priority Date: 07/27/2012
• Status: Active Grant

• Current Assignee: Boston Scientific Neuromodulation Corporation (Boston Scientific Corporation)
• Original Assignee: Boston Scientific Neuromodulation Corporation (Boston Scientific Corporation)
• Inventors: Zhu, Changfang, Bradley, Kerry
• Primary Examiner(s): Holmes, Rex R
• Application Number:
  US13/944,593
• Publication Number:
  US 20140031901A1
• Time in Patent Office: 412 Days
• Field of Search: 607 60- 63
• US Class Current: 607/60
• CPC Class Codes: A61B 5/053 Measuring electrical impedance or conductance of a portion of the body
• CPC Class Codes: A61B 5/055 involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
• CPC Class Codes: A61N 1/086 Magnetic resonance imaging [MRI] compatible leads
• CPC Class Codes: A61N 1/36125 Details of circuitry or electric components
• CPC Class Codes: A61N 1/36128 Control systems

Abstract

A neurostimulation system and method of operating an implantable neurostimulation device configured for outputting electrical stimulation energy to at least one electrode in accordance with a set of stimulation parameters. The implantable neurostimulation device may be switched from a normal operating mode to a Magnetic Resonance Imaging (MRI) operating mode. Electrical parameter measurements may be repeatedly acquired at each of the electrode(s) in response to the placement of the implantable stimulation system in the MRI mode. A corrective action may be performed based on at least one of the repeatedly acquired electrical parameter measurements.

Claims

1. A neurostimulation system, comprising:

at least one stimulation lead carrying at least one electrode;

stimulation output circuitry coupled to the at least one stimulation lead, the stimulation output circuitry configured for outputting electrical stimulation energy to the at least one electrode in accordance with a set of stimulation parameters;

a controller/processor configured for placing the stimulation system between a Magnetic Resonance Imaging (MRI) operating mode and a normal operating mode; and

monitoring circuitry configured for acquiring electrical parameter measurements at each of the at least one electrode in response to the placement of the stimulation system in the MRI mode;

wherein the controller/processor is further configured for determining an electrode-tissue coupling efficiency based on at least one of the repeatedly acquired electrical parameter measurements, comparing the determined electrode-tissue coupling efficiency to a reference electrode-tissue coupling efficiency, and generating a new set of stimulation parameters based on the comparison, wherein the stimulation output circuitry is configured for outputting electrical stimulation energy to the at least one electrode in accordance with the new set of stimulation parameters.

2. The neurostimulation system of claim 1, wherein each of the electrical parameter measurements comprises one of an impedance measurement and a field potential measurement.

3. The neurostimulation system of claim 1, wherein the controller/processor is configured for instructing the stimulation output circuitry to convey electrical energy to each of the at least one electrode, wherein each of the electrical parameter measurements is taken by measuring at least one electrical parameter in response to the conveyed electrical energy.

4. The neurostimulation system of claim 1, wherein the controller/processor is further configured for determining a defect in at least one of the electrodes based on the at least one of the acquired electrical parameter measurements, and generating an alert signal in response to determining the defect.

5. The neurostimulation system of claim 4, wherein the defect is one of a short circuit and an open circuit.

6. The neurostimulation system of claim 4, wherein the alert signal is a binary signal.

7. The neurostimulation system of claim 4, wherein the alert signal is one of a visual signal, an aural signal, a vibratory signal, and a modulated neurostimulation signal.

8. The neurostimulation system of claim 1, further comprising a user interface configured for receiving input from a user, wherein the controller/processor is configured for placing the stimulation system in the MRI operating mode in response to the user input.

9. The neurostimulation system of claim 1, wherein the monitoring circuitry is configured for sensing energy emitted by an MRI scanner, and the controller/processor is configured for placing the stimulation system in the MRI operating mode in response to the sensed energy.

10. A method of operating an implantable neurostimulation device configured for outputting electrical stimulation energy to at least one electrode in accordance with a set of stimulation parameters, the method comprising:

switching the implantable neurostimulation device from a normal operating mode to a Magnetic Resonance Imaging (MRI) operating mode;

acquiring electrical parameter measurements at each of the at least one electrode in response to the placement of the implantable stimulation system in the MRI mode;

determining an electrode-tissue coupling efficiency based on at least one of the repeatedly acquired electrical parameter measurements, comparing the determined electrode-tissue coupling efficiency to a reference electrode-tissue coupling efficiency, generating a new set of stimulation parameters based on the comparison, and outputting electrical stimulation energy to the at least one electrode in accordance with the new set of stimulation parameters.

11. The method of claim 10, wherein each of the electrical parameter measurements comprises one of an impedance measurement and a field potential measurement.

12. The method of claim 10, further comprising conveying electrical energy to each of the at least one electrode, wherein each of the electrical parameter measurements is taken by measuring at least one electrical parameter in response to the conveyed electrical energy.

13. The method of claim 10, further comprising determining a defect in at least one of the electrodes based on the at least one of the acquired electrical parameter measurements, and generating an alert signal in response to determining the defect.

14. The method of claim 13, wherein the defect is one of a short circuit and an open circuit.

15. The method of claim 13, wherein the alert signal is a binary signal.

16. The method of claim 13, wherein the alert signal is one of a visual signal, an aural signal, a vibratory signal, and a modulated neurostimulation signal.

17. The method of claim 10, further comprising receiving input from a user, wherein the implantable neurostimulation device is switched to the MRI operating mode in response to the user input.

18. The method of claim 10, further comprising sensing energy emitted by an MRI scanner, wherein the implantable neurostimulation device is switched to the MRI operating mode in response to the sensed energy.