Method and system for controlling electrical conditions of tissue

• US 10,206,596 B2
• Filed: 11/06/2013
• Issued: 02/19/2019
• Est. Priority Date: 11/06/2012
• Status: Active Grant

• Current Assignee: Saluda Medical Pty Ltd.
• Original Assignee: Saluda Medical Pty Ltd.
• Inventors: Single, Peter Scott Vallack, Laird-Wah, James Hamilton
• Primary Examiner(s): Henson, Devin
• Application Number:
  US14/440,873
• Publication Number:
  US 20150313487A1
• Time in Patent Office: 1,931 Days
• CPC Class Codes: A61B 5/24 Detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof
• CPC Class Codes: A61B 5/30 Input circuits therefor
• CPC Class Codes: A61B 5/4041 Evaluating nerves condition
• CPC Class Codes: A61B 5/4848 Monitoring or testing the effects of treatment, e.g. of medication
• CPC Class Codes: A61B 5/686 Permanently implanted devices, e.g. pacemakers, other stimulators, biochips A61B5/6861 takes precedence
• CPC Class Codes: A61B 5/7203 for noise prevention, reduction or removal
• CPC Class Codes: A61B 5/7217 of noise originating from a therapeutic or surgical apparatus, e.g. from a pacemaker
• CPC Class Codes: A61B 5/7225 Details of analog processing, e.g. isolation amplifier, gain or sensitivity adjustment, filtering, baseline or drift compensation A61B5/30, A61B5/316 take precedence; transformers for specific applications H01F38/00; amplifiers H03F
• CPC Class Codes: A61B 5/7228 Signal modulation applied to the input signal sent to patient or subject; demodulation to recover the physiological signal modulation H03C
• CPC Class Codes: A61B 5/7296 for compensation of signal variation due to stress unintentionally induced in the patient, e.g. due to the stress of the medical environment or examination deliberately inducing physiological or psychological stress A61B5/4884
• CPC Class Codes: A61N 1/36125 Details of circuitry or electric components
• CPC Class Codes: A61N 1/36132 using patient feedback
• CPC Class Codes: A61N 1/36139 with automatic adjustment
• CPC Class Codes: A61N 1/36146 specified by the stimulation parameters

Abstract

An implantable device for controlling electrical conditions of body tissue. A feedback sense electrode and a compensation electrode are positioned proximal to the tissue to make electrical contact with the tissue. A feedback amplifier is referenced to ground, and takes as an input a feedback signal from the feedback sense electrode. The output of the feedback amplifier is connected to the compensation electrode. The feedback amplifier thus drives the neural tissue via the compensation electrode in a feedback arrangement which seeks to drive the feedback signal to ground, or other desired electrical value.

Claims

1. A method for measuring a neural response to a stimulus, the method comprising:

providing a plurality of implantable electrodes including at least one nominal stimulus electrode, at least one nominal measurement electrode, at least one nominal feedback sense electrode and at least one nominal compensation electrode, the electrodes being implanted proximal to a neural tissue and being in electrical contact with the neural tissue;

applying an electrical stimulus to the neural tissue from the at least one stimulus electrode;

during an application of the stimulus, connecting a feedback signal from the at least one feedback sense electrode to an input of a feedback amplifier, and referencing the feedback amplifier to a desired electrical value;

during an application of the stimulus, connecting an output of the feedback amplifier to the at least one compensation electrode such that the feedback amplifier drives the neural tissue via the at least one compensation electrode in a feedback arrangement which seeks to drive the neural tissue to the desired electrical value; and

obtaining a measurement of a neural response from the at least one measurement electrode.

2. The method of claim 1 wherein the desired electrical value is electrical ground referenced to a patient ground electrode distal from the at least one feedback sense electrode.

3. The method of claim 1 wherein, during the entire period of stimulation, the feedback amplifier operates and is in connection with the at least one feedback sense electrode and at least one compensation electrode.

4. The method of claim 1 wherein the at least one feedback sense electrode and the at least one measurement electrode are located outside a dipole formed by the at least one stimulus electrode and the at least one compensating electrode.

5. An implantable device for controlling electrical conditions of tissue, the device comprising:

a plurality of implantable electrodes including at least one nominal feedback sense electrode, at least one nominal compensation electrode, at least one nominal stimulus electrode, and at least one nominal sense electrode;

the electrodes being configured to be implanted proximal to the tissue to make electrical contact with the tissue;

a stimulus source for providing an electrical stimulus to be delivered from the at least one stimulus electrode to neural tissue;

measurement circuitry for amplifying a neural signal sensed at the at least one sense electrode; and

a feedback amplifier configured to be referenced to a desired electrical value and to take as an input a feedback signal from the feedback sense electrode during application of the stimulus, an output of the feedback amplifier being connected to the compensation electrode such that the feedback amplifier is configured to drive the neural tissue via the compensation electrode during application of the stimulus in a feedback arrangement which seeks to drive the feedback signal to the desired electrical value.

6. The device of claim 5 wherein the feedback amplifier is configured to operate in connection with the feedback sense electrode and compensation electrode during an entire period of the electrical stimulus.

7. The device of claim 5 wherein the desired electrical value is electrical ground referenced to a patient ground electrode distal from the feedback sense electrode.

8. The device of claim 5 wherein the feedback sense electrode and the measurement electrode are located outside a dipole formed by the stimulus electrode and the compensating electrode.