Core MEG system

Magnetoencephalography (MEG)

The core system at NatMEG is a HEDSCAN OPM-MEG
system with 136 dual-axis sensors and Smart Helmet
(144 slots) from Fieldline Inc.

Electroencephalography (EEG)

The Elekta Neuromag TRIUX  has an integrated
MEG-compatible  128 channel EEG system. 

Further technical specifications are found here.

System technical manual is found here.

We currently use 128 channel caps, 74 channel caps and
128-slit custom montage caps from  EasyCap

Biochannels

A MP150 system from Biopac with one ECG100C, two EOG100C, and RSP100C are used for recording electrocardiogram (ECG), electrooculogram (EOG) and respiration, respectively. 

The Elekta Neuromag TRIUX also has 12 integrated bipolar channels, for recording of EOG, ECG, and electromyography (EMG). 

Further technical specifications are found here.

System technical manual is found here.

We currently use the EL508 electrodes and  LEAD108 and LEAD108a from BioPac for most biochannel measurements. We also use  the EL254RT  for facial EMG.

Triggers and time-locking

A total of 32 digital channels and 24 analog channels  are sampled in parallell and synchronized to the MEG, EEG and biochannels data.

Further technical specifications are found here.

System technical manual is found here.

Magnetically shielded room (MSR)

 All MEG/EEG recordings are done within a two-layer MSR, model Ak3B from Vacuumschmelze GmbH. 

Further technical specifications for the MSR are found here.

For an overview of  the MSR shielding factor across frequencies, see here.

Co-registration

Co-registration of functional MEG/EEG data with structural MRIs for source reconstruction can be done either using a Fastrak digitizer from Polhemus or a Einscan H structured-light 3D-scanner from Shining 3D. 

Further technical specifications for the Einscan H are found here.

Further technical specifications for the Fastrak are found here.