Improved circuitry and post-processing for interleaved fast-scan cyclic voltammetry and electrophysiology...

Area of Science:

• Neuroscience
• Biomedical Engineering
• Signal Processing

Background:

• Combined electrophysiology and electrochemistry using carbon fiber microelectrodes (CFMs) allow extensive analysis of neural activity and neurochemical release.
• Analog CMOS switches used in these systems introduce charge injection artifacts, delaying signal recovery and attenuating important low-frequency local-field potential (LFP) data.

Purpose of the Study:

• To develop a method that overcomes charge injection artifacts in interleaved electrophysiology and electrochemistry recordings.
• To preserve valuable low-frequency LFP bands while improving signal recovery speed.

Main Methods:

• Integrated a voltage follower operational amplifier before the CMOS switch to increase current flow and dissipate injected charge.
• Implemented single-term exponential modeling in post-processing to characterize and subtract remaining transient voltage artifacts.

Main Results:

• Achieved a 16.98% decrease in electrophysiology acquisition delay with the hardware addition.
• Reduced electrophysiology data recovery time to 3.26 ± 0.22 ms, a 60% improvement over previous methods.
• Minimized attenuation of LFP signals, preserving network-level insights.

Conclusions:

• The proposed hardware and software solution effectively mitigates charge injection artifacts in coupled electrophysiology and electrochemistry recordings.
• This advancement enables higher scan rates for combined measurements, enhancing the comprehensive analysis of neural activity and neurochemical release.