A Diagnostic Circuit for Crosstalk Detection in Microelectrode Arrays.

Area of Science:

• Neuroscience
• Biomedical Engineering
• Electrical Engineering

Background:

• Current leakage in microelectrode arrays indicates device failure and can corrupt neural signals.
• Detecting crosstalk is crucial for ensuring the integrity of neural recordings.
• Implantable neural devices require robust methods for functional testing.

Purpose of the Study:

• To design and implement an embedded system for detecting crosstalk between 32 channels of microelectrodes.
• To quantify crosstalk levels and identify potential signal interference.
• To assess the reliability of microelectrode arrays for neural signal acquisition.

Main Methods:

• Developed an embedded system to individually stimulate each electrode with a constant-current pulse.
• Recorded voltage transients from stimulated and adjacent electrodes.
• Utilized charge injection in phosphate buffered saline for electrode condition assessment.
• Employed a semi-wet condition to measure inter-electrode crosstalk percentages.

Main Results:

• The system successfully generated a matrix of crosstalk values for 32 channels.
• Minimal crosstalk was observed between most electrodes.
• A known physical defect on the probe was identified as the primary source of significant crosstalk.
• The charge injection test confirmed the condition of individual electrodes.

Conclusions:

• The developed measurement technique and electronics circuit are effective for detecting microelectrode crosstalk.
• The system demonstrates potential for functional testing and screening of implantable neural devices.
• Accurate crosstalk detection is vital for maintaining signal fidelity in neural interfaces.