Method for measuring stable and reproducible electrode-tissue impedance

Patent metadata

Field	Value
Publication number	US-9802045-B2
Application number	US-92443607-A
Country	US
Kind code	B2
Filing date	Oct 25, 2007
Priority date	Sep 29, 2006
Publication date	Oct 31, 2017
Grant date	Oct 31, 2017

Abstract

The present invention is a method for measuring stable and reproducible electrode-tissue impedance, comprising preconditioning an electrode-tissue interface. Further aspect of the invention is a stimulation system for a visual prosthesis generating a stimulation signal to precondition the electrode-tissue interface, comprising a computer; software, loaded in the computer, adapted to perform a stimulating method for a visual prosthesis having a plurality of electrodes; a video processing unit; and an implanted neuron-stimulator.

First claim

What we claim is:

1. A method for measuring stable and reproducible electrode-tissue impedance, comprising:
providing a stimulation system including a computer;
software, loaded in the computer, adapted to perform a stimulating method for a visual prosthesis having a plurality of electrodes;
a video processing unit; and
an implanted neuron-stimulator including at least one electrode;

preconditioning the electrode-tissue interface by delivering a first stimulation signal, including charge balanced biphasic square wave current pulses for a duration suitable to precondition the electrode interface to the electrode, the duration being between 1 second and 10 minutes;
stopping preconditioning at the end of the duration;
measuring an impedance on the electrode at similar electrode-tissue interface conditions to the preconditioning step, after said preconditioning step within a predetermined delay;
transmitting the impedance wirelessly to a computer; and
estimating perceptual thresholds based on the impedance.

2. The method for measuring stable and reproducible electrode-tissue impedance according to claim 1 wherein the electrode-tissue impedance is measured in vivo.

3. The method for measuring stable and reproducible electrode-tissue impedance according to claim 1 wherein preconditioning of the electrode-tissue interface is carried out one electrode at a time or in groups of electrodes.

4. The method for measuring stable and reproducible electrode-tissue impedance according to claim 1 wherein preconditioning of the electrode-tissue interface is carried out for all electrodes simultaneously.

5. The method for measuring stable and reproducible electrode-tissue impedance according to claim 4 further comprising varying a combination of variable pulse-width amplitude and frequency is used to control preconditioning of the electrode-tissue interface.

6. The method for measuring stable and reproducible electrode-tissue impedance according to claim 1 , comprising preconditioning at 10-300 μA at 15-120 Hz with 0.1-2.0 ms pulse width.

7. The method for measuring stable and reproducible electrode-tissue impedance according to claim 1 , comprising preconditioning at 30-150 μA at 30-120 Hz with 0.2-1.0 ms pulse width.

8. The method for measuring stable and reproducible electrode-tissue impedance according to claim 1 , comprising: preconditioning at 80-120 μA at 40-60 Hz with 0.4-0.6 ms pulse width.

9. The method for measuring stable and reproducible electrode-tissue impedance according to claim 1 , wherein the step of measure is measuring with charge balanced square wave current pulses.

Assignees

• Hines Amy Chu Peishuan
• Zhou Dao Min
• Roy Arup
• Dai Rongqing
• Greenberg Robert J
• Second Sight Medical Products Inc

Inventors

• Hines Amy Chu Peishuan
• Zhou Dao Min
• Roy Arup
• Dai Rongqing
• Greenberg Robert J

Classifications

• A61N1/0543

  Retinal electrodes · CPC title

• A61N1/36046 Primary

  of the eye · CPC title