Method and apparatus to provide safety checks for neural stimulation

Patent metadata

Field	Value
Publication number	US-11173305-B2
Application number	US-201916516046-A
Country	US
Kind code	B2
Filing date	Jul 18, 2019
Priority date	Apr 28, 2006
Publication date	Nov 16, 2021
Grant date	Nov 16, 2021

Abstract

In electrically stimulating neural tissue it is important to prevent over stimulation and unbalanced stimulation, which would cause damage to the neural tissue, the electrode, or both. It is critical that neural tissue is not subjected to any direct current or alternating current above a safe threshold. Further, it is important to identify defective electrodes, as continued use may result in neural damage and further electrode damage. The present invention presents system and stimulator control mechanisms to prevent damage to neural tissue.

First claim

The invention claimed is:

1. A method of stimulating neural tissue comprising:
providing a neural stimulator including a plurality of electrodes suitable to stimulate neural tissue;
determining a maximum total charge per phase for the plurality of electrodes;
receiving input for neural stimulation for each of the plurality of electrodes;
calculating a discrete integral of a wave form of the input for neural stimulation for each of the plurality of electrodes to determine a charge per phase for each of the plurality of electrodes;
adding the charge per phase of each of the plurality of electrodes to find a total charge per phase;
reducing the stimulation on each of the plurality of electrodes by an amount necessary not to exceed the maximum total charge per phase for the plurality of electrodes; and
stimulating the neural tissue according to the input for neural stimulation, reduced to not exceed the maximum total charge per phase.

2. The method according to claim 1 , further comprising an external input from a video processor.

3. The method according to claim 1 , wherein the step of stimulating neural tissue is stimulating visual neural tissue to form artificial vision.

4. The method according to claim 1 , wherein the step of stimulating neural tissue according to the input for neural stimulation includes receiving input from multiple sources.

5. The method according to claim 1 , wherein the step of stimulating neural tissue is stimulating with charged balanced cathodic and anodic pulses.

6. The method according to claim 5 , further comprising shorting the electrodes to ground after the anodic pulses.

7. The method according to claim 6 , further comprising measuring leakage current on each electrode when the electrode is shorted to ground.

8. The method according to claim 7 , further comprising disabling a driver related to an electrode within the plurality of electrodes when leakage current is detected on the electrode.

9. The method according to claim 8 , further comprising transmitting an error signal when leakage current is detected.

Assignees

• Second Sight Medical Products Inc

Inventors

• Greenberg Robert Jay
• Mcclure Kelly Hobart
• Little James S
• Dai Rongqing
• Roy Arup
• Castro Richard Agustin
• Reinhold John
• Tang Kea-Tiong
• Yadav Sumit
• Zhou Chunhong
• Zhou David Daomin
• Maksy Pishoy

Classifications

• A61N1/36185

  Selection of the electrode configuration · CPC title

• A61N1/36046 Primary

  of the eye · CPC title

• A61N1/00

  Electrotherapy; Circuits therefor (A61N2/00 takes precedence; irradiation apparatus A61N5/00) · CPC title

• A61N1/36142

  for improving safety · CPC title

• A61N1/0543

  Retinal electrodes · CPC title