Iris 128x: open-source 128 channel headstages for neural stimulation and recording

Area of Science:

• Neuroscience
• Biomedical Engineering
• Open-Source Hardware

Background:

• Complex neural circuit investigation requires high-channel-count neural interfaces.
• Current commercial neural headstages face limitations in scalability, proprietary designs, and bidirectional capabilities, hindering research accessibility.

Purpose of the Study:

• To introduce two open-source, 128-channel neural headstages, Iris 128B and Iris 128S.
• To provide researchers with accessible, scalable, and bidirectional neural recording and stimulation tools.

Main Methods:

• Designed and implemented two 128-channel headstages (Iris 128B and Iris 128S) using Intan Technologies' integrated circuits.
• Validated headstage performance through benchtop measurements (impedance, noise, frequency response) and acute in vivo recordings in rats.

Main Results:

• Both headstages demonstrated low noise levels and reliable signal acquisition across all channels.
• Iris 128B offers bidirectional interfacing on 128 channels; Iris 128S provides 128-channel recording and 16-channel stimulation.

Conclusions:

• The open-source headstage designs facilitate broader adoption of bidirectional neural recording and stimulation systems.
• Future work will focus on miniaturization and wireless integration for chronic small animal experiments.