# US 10,946,199 B2 · Neurostimulation method and system for active emulation of passive discharge in presence of MRI/EMI interference

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 10,946,199 B2
- Document ID: US10946199B2
- Status: Granted
- Kind: B2
- Application number: 16/401,943
- Filed: 2019-05-02
- Published: 2020-11-05
- Granted: 2021-03-16
- Earliest claimed: 2019-05-02
- Assignees: Advanced Neuromodulation Systems, Inc.
- Applicants: Advanced Neuromodulation Systems, Inc.
- Inventors: Steven Boor; Daran DeShazo
- Web page: https://patentgrep.com/patent/US10946199B2

## CPC

- A61N 1/36071: {Pain}
- A61N 1/36192: {Amplitude modulation}
- A61N 1/08: Arrangements or circuits for monitoring, protecting, controlling or indicating {(for external stimulators A61N1/3603; for implantable neurostimulators A61N1/36128; for heart stimulators A61N1/37; for defibrillators A61N1/3925)}
- A61N 1/0452: {Specially adapted for transcutaneous muscle stimulation [TMS]}
- A61N 1/0456: {Specially adapted for transcutaneous electrical nerve stimulation [TENS]}
- A61N 1/0534: {Electrodes for deep brain stimulation}
- A61N 1/0551: {Spinal or peripheral nerve electrodes}
- A61N 1/086: {Magnetic resonance imaging [MRI] compatible leads}
- A61N: ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY (measurement of bioelectric currents A61B; surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body A61B18/00; anaesthetic apparatus in general A61M; incandescent lamps H01K; infrared radiators for heating H05B)

## Abstract

A neurostimulation system (NS) includes an array of electrodes positioned within a patient with an active cathode electrode located proximate to target neural tissue. A control circuit is controls delivery of therapy during a therapy delivery interval, with the therapy being delivered between an anode electrode and the active electrode. A current regulator circuit (CRC) is connected to the cathode electrode and controls current flow through the cathode electrodes. The control circuit manages the CRC to control a discharge current flow over the discharge operation to discharge developed residual voltage between the anode electrode and the active electrode in a manner that follows an actively emulated passive discharge (AEPD) profile. During the discharge operation, the CRC is connected to the inactive electrode, and receives, as a first input, an EMI feedback signal. The CRC regulates the discharge current flow through the active electrode based on the EMI feedback signal, to maintain the AEPD profile over the discharge operation during an EMI event.

## Claims

### Claim 1

A neurostimulation (NS) system, comprising:
an array of electrodes positioned within a patient, the array of electrodes including an active electrode, the active electrode configured to be a cathode electrode located proximate to neural tissue of interest that is associated with a target region;
an anode electrode;
an electromagnetic interference (EMI) antenna;
a control circuit configured to control delivery of a NS therapy during a therapy delivery interval, the NS therapy to be delivered between the anode electrode and the active electrode, the NS system developing a residual voltage between the anode electrode and the active electrode over the therapy delivery Interval;
a current regulator (CR) circuit connected to the cathode electrode, the CR circuit configured to control current flow through the cathode electrodes;
during a discharge operation, the control circuit configured to manage the CR circuit to control a discharge current flow over the discharge operation to discharge the residual voltage after therapy delivery in a manner that follows an actively emulated passive discharge (AEPD) profile; and
during the discharge operation, the CR circuit connected to the EMI antenna, the CR circuit receiving, as a first input, an EMI feedback signal from the EMI antenna, the CR circuit configured to regulate the discharge current flow through the active electrode based on the EMI feedback signal, to maintain the AEPD profile over the discharge operation while in a presence of an EMI event.

### Claim 2 (depends on 1)

The NS system of claim 1, wherein the EMI antenna is configured to generate the EMI feedback signal indicative of a voltage interference induced at least In part by an electromagnetic field surrounding the NS system.

### Claim 3 (depends on 1)

The NS system of claim 1, wherein the EMI antenna includes at least one of: i) an Inactive electrode from the array of electrodes, and ii) a non-electrode wire within a lead or routed with insulation substantially alongside the outside of the lead, having the array of electrodes provided at a distal end of the NS lead.

### Claim 4 (depends on 1)

The NS system of claim 1, further comprising a reference voltage source configured to supply a reference voltage as a second input to the CR circuit, the CR circuit configured to regulate the current flow through the active and anode electrodes based on a difference between the EMI feedback signal and the reference voltage.

### Claim 5 (depends on 1)

The NS system of claim 1, wherein the CR circuit comprises an error amplifier and a transistor, the error amplifier configured to hold the EMI feedback signal at a reference voltage and provide an output based thereon, the transistor configured to regulate the current flow through the active and anode electrodes based on the output of the error amplifier to maintain the AEPD profile while in the presence of the EMI event.

### Claim 6 (depends on 1)

The NS system of claim 1, wherein the EMI antenna includes an inactive electrode, and wherein the inactive electrode and the active electrode are configured to have substantially similar electrical properties.

### Claim 7 (depends on 1)

The NS system of claim 1, further comprising a lead having a distal end that includes the array of electrodes, the EMI antenna including a non-electrode wire within the lead or a wire routed with insulation substantially alongside the outside of the lead.

### Claim 8 (depends on 1)

The NS system of claim 1, wherein the EMI antenna is configured to sense and mitigate interference from EMI.

### Claim 9 (depends on 1)

The NS system of claim 1, wherein the control circuit is configured to deliver the NS therapy repeatedly over successive therapy delivery intervals that are separated by corresponding successive discharge operations while in the presence of the EMI event.

### Claim 10 (depends on 9)

The NS system of claim 9, wherein the CR circuit is configured to modulate the current flow over the discharge operation, based on the EMI feedback signal, in order to follow the AEPD profile to compensate for voltage fluctuation caused by the EMI event.

### Claim 11

A method for managing neurostimulation (NS), the method comprising:
providing an array of electrodes to be located proximate to neural tissue of interest that is associated with a target region, the array of electrodes including an active electrode configured to be a cathode electrode;
delivering a NS therapy during a therapy delivery interval between an anode electrode and the active electrode, the NS system developing a residual voltage between the anode electrode and the active electrode over the therapy delivery interval; and
during a discharge operation in a presence of an EMI event:
controlling a discharge current flow over the discharge operation to discharge the residual voltage after therapy delivery in a manner that follows an actively emulated passive discharge (AEPD) profile;
obtaining an electromagnetic interference (EMI) feedback signal from an EMI antenna while in the presence of the EMI event; and
regulating the discharge current flow through the anode and cathode electrodes based on the EMI feedback signal to maintain the AEPD profile over the discharge operation while in the presence of the EMI event.

### Claim 12 (depends on 11)

The NS method of claim 11, wherein the EMI feedback signal is indicative of a voltage interference induced at least in part by an electromagnetic field surrounding the NS system.

### Claim 13 (depends on 12)

The NS method of claim 12, wherein the voltage gradient is induced between the EMI antenna and the anode electrode.

### Claim 14 (depends on 11)

The NS method of claim 11, further comprising supplying a reference voltage, and regulating the current flow based on a difference between the EMI feedback signal and the reference voltage.

### Claim 15 (depends on 11)

The NS method of claim 11, wherein the controlling operation further comprises:
utilizing a current regulator (CR) circuit that comprises an error amplifier and a transistor;
comparing the EMI feedback signal to a reference voltage at the error amplifier and provide an output based thereon; and
utilizing the transistor to regulate the discharge current flow through the anode and cathode electrodes based on the output of the error amplifier to maintain the AEPD profile while in the presence of the EMI event.

### Claim 16 (depends on 11)

The NS method of claim 11, further comprising utilizing an inactive electrode as the EMI antenna and configuring the inactive electrode and the active electrode to have substantially similar electrical properties.

### Claim 17 (depends on 11)

The NS method of claim 11, further comprising implanting a lead having a distal end that includes the array of electrodes and utilizing a non-electrode wire within the lead or a wire routed with insulation substantially alongside an outside of the lead as the EMI antenna.

### Claim 18 (depends on 11)

The NS method of claim 11, further comprising implanting an implantable pulse generator that houses a control circuit and current regulator (CR) circuit that deliver the NS therapy and control the discharge current flow during the discharge operation.

### Claim 19 (depends on 11)

The NS method of claim 11, wherein the delivering operation further comprises delivering the NS therapy repeatedly over successive therapy delivery intervals that are separated by corresponding successive discharge operations while in the presence of the EMI event.

### Claim 20 (depends on 19)

The NS method of claim 19, wherein the regulating operation further comprises compensating for voltage fluctuation caused by the EMI event by modulating the discharge current flow over the discharge operation, based on the EMI feedback signal, in order to follow the AEPD profile.