EEG breakout board

Owned by Christopher Black
Last updated: Mar 15, 2015
2 min read

This is the first version of the Open Ephys EEG adapter currently supporting two types of connectors.  It provides a basic interface between select EEG caps and the Open Ephys headstage.

Both connectors source to single omnetics connector.

All ground and ref connections are linked by a series of headers so ground and ref connections can be severed while maintaining their functionality.

**Make sure you tie together ground and ref on board.

Passive Caps

EEG caps that no active electrical components between system amps and electrodes. Some passive caps might implement resistors before reaching the amps.

Breakout board V 2.0

This adaptor works with any passive, Pak50 50 pin EEG cap.  It has four Pak50 connectors, and four omnetics connectors to support up 128 channels of EEG data.

There is also more versatility in this version; up to four of the omnetics positions in the first connector can be dedicated to other types of recording (EMG, EKG, EOG).  These recording sites can be changed on the fly using a series of jumpers.


Breakout board V 1.0

Pak50 connector 

For EASYCAP products using 50 pin Pak50 connectors operating off of 32 channels or more.  The connector consists of four columns with a 13-12-13-12 scheme for a total of 50 solder feet (denoted by pads on the board layout).  Male connector provides two contact points with 0.05" pitch*. Connector interfaces with female socket of a flat ribbon cable.

  • Ground: Pad is in the third column from the left, first pad at the bottom.
  • Reference: Pad is the first column on the left, 7 pads up from the bottom.

40 Pin connector

From Neuroscan Compumedics Quik-Cap (United States) and is compatible with any Quik-Cap operating of 40 channels or more.  It is a very basic connector consisting of forty headers with a 0.1" pitch aligned in two parallel rows of twenty.  

  • Ground: Pin is located on the bottom row 16 headers in from the left.
  • Reference: Pin is on the top row 7 headers in from the left. 

 

Active Caps

These caps have electrode with pre-amplifiers to help reduce noise picked up by electrode leads.  Currently non-compatible with EEG breakout board.

  • Determine the gain on the active-electrode amps; might need to adjust gain on intan amps.

 

Download Files

Gerber files zip for PCB

Board Layout

Schematic Layout

Files are also available on the Github page.

EEG breakout board