BrainCap MR: Superior electrode system for simultaneous EEG-fMRI

The simultaneous recording of EEG-fMRI data is a well-established technique and our MRI product portfolio is the gold standard for this application. We strive to keep our products up to date to guarantee the highest safety and comfort for the participant as well as outstanding data quality. As such, our BrainCap MR Rev. 3 (from April 2020) has evolved in recent years to keep up with the demands of this dynamic research area.

The BrainCap MR is available for BrainAmp MR amplifiers and can be used in scanners up to 3 T. Its use is subject to our general 3 T EEG-fMRI safety guidelines.

Highest safety standards

• • All electrodes in the BrainCap MR Rev. 3 are fitted with serial current-limiting resistors.
  • Resistors are also placed inside the cap connector, for additional current limiting.
  • Small gaps are inserted into the electrode rings to avoid induction in closed loops.
  • ECG electrodes contain higher resistors than EEG electrodes to compensate for the technical characteristics of longer wires.
  • Electrode cables are routed on the outside of the cap and secured to avoid loops and cable movement.
  • The drop-down electrodes (e.g. ECG) are sheathed in plastic to avoid direct contact with the skin of the participant.
  • Wire length from electrode to the amplifier input is fixed to the minimal required length.
  • Cable tree exit point options are available to fit with different MRI head coils.
  • Clear MR labelling and safety guidelines are in line with industry standards.

Guaranteed comfort

• • Flat electrodes guarantee the comfort of the cap when the head is resting on the electrodes in a supine position inside the MR scanner.
  • Empty electrode holders are added to caps with fewer than 64 channels to compensate for gaps between the electrodes and more evenly distribute pressure when the head is resting on the electrodes inside the MR scanner.
  • A new cap cut has been adopted that encompasses more of the head, cheeks and neck. As a result, these caps fit better on more head shapes, and they rarely slip backwards from frontopolar sites.

Ease of use

• • Serial number sticker for easy tracking, assembly and layout questions
  • Colored electrode holders for easy access/clarification of assembly affiliation (e.g. 10-20, 10-10)
  • Name labels on every electrode for easy recognition

What happens to old electrode caps that do not meet the current safety standards?

If you have an older BrainCap MR (before April 2020) there is no urgent need to change your cap. You can continue to use your caps in your current setup as long as you continue to adhere to the safety guidelines. The only difference in the safety guidelines for older caps compared to the new ones is that the sequence limitations are stricter for old caps. This is due to the longer cable tree on older caps (see our MR sequence guidelines). It is worth considering replacing your old BrainCap MR with the latest version if you would like to benefit from the new safety standards and the increased flexibility regarding the MRI sequence limitations.