BrainAmp MR series

Logo - BrainAmps MR
  • Gold standard amplifier solutions for simultaneous EEG-fMRI recordings

  • Up to 256 channels (lab) / 128 channels (MR environment): Stackable 32 channel units

  • Amplifier and battery can be placed in the MR scanner bore

  • Expandable with the BrainAmp ExG MR for bipolar and sensor data acquisition

BrainAmp MR: Superior solutions for recording EEG in the MR environment

Our BrainAmp MR amplifiers are gold standard solutions for simultaneous EEG-fMRI co-registrations. They have been on the market since the early 2000s and their extremely high data quality (in the MR and the lab environment), their ease of use, as well as unparalleled scientific and technical support make them a first choice for researchers around the world. There are hundreds of scientific publications in the EEG-fMRI field citing our BrainAmp MR amplifiers and the number is still growing.

BrainAmp MROutstanding technical features (BrainAmp MR plus)
    • Sampling rate: 5 kHz per channel
    • Input noise: ≤ 1 μVpp
    • Common-mode rejection (CMR): ≥ 110 dB
    • Operating time between battery charges: Typically 30 hours (when used with one amplifier)
Powered by lead gel technology (the PowerPack)
    • Fully eliminates 50/60 Hz mains noise originating from power supplies, ensuring highest quality EEG/ERP recordings
    • Can be used for continuous acquisitions of up to 30 hours and allows for more than 1000 recharging cycles
    • Labeled “MR conditional” and therefore suitable for safe EEG recordings in the MR scanner
Excellent data quality and high safety standards
    • Shielded amplifier which can be taken directly inside the MRI chamber and placed in the bore right behind the participant’s head
    • Sends digitized signal via fiber optic cable to the USB interface (USB2 Adapter / BUA) located in the control room, i.e. no artifacts are added along the way
    • Short cable length connecting electrode cap and amplifier fulfills the highest safety requirements for the participant and guarantees outstanding data quality
Flexibility
    • Several 32 channel units can be stacked to expand the number of channels up to 128 in the MR environment (even up to 256 channels in the lab environment)
    • Can be used in combination with passive gel-based electrodes (BrainCap MR) or passive sponge-based electrodes (R-Net MR) in the MR environment (and also with active dry or gel-based electrodes in a non-MR lab environment)
Expandability

The EEG amplifier systems can be combined with the BrainAmp ExG MR to add the capability to record bipolar and peripheral signals, such as EOG, ECG, EMG, GSR/EDA, Respiration, Acceleration, etc. in a compact setup.

BrainAmp MR
    • Only offers AC recording mode
    • Comes with amplifier, battery (PowerPack), USB2 Adapter/BUA (connection to computer), Signaltester, carrying box and all required cabling
BrainAmp MR plus
    • Includes all features of the BrainAmp MR with the addition of a DC recording mode and multiple hardware filtering options. The amplifier setup is fully controllable via the recording software. It is possible to switch from DC to AC recording mode as well as to select different hardware bandwidths with just one “click” in the software.
    • Comes with amplifier, battery (PowerPack), USB2 Adapter/BUA (connection to computer), Signaltester, carrying box and all required cabling
BrainAmp ExG MR
    • Bipolar 16 channel amplifier to record EOG, ECG, EMG and other peripheral signals such as GSR (Galvanic Skin Response), respiration, and acceleration in the MR environment
    • Based on the same technology as BrainAmp MR and MR plus
    • Available as an extension or stand-alone system
    • Comes with amplifier, battery (PowerPack), USB2 Adapter/BUA (connection to computer), AUX box (connection of sensors), Signaltester and all required cabling
BrainAmpTechnical specifications
AmplifierBrainAmp MRBrainAmp MR plusBrainAmp ExG MR
Number of channels (per unit)323216
Channel type / referenceReferential channels/acquisition of a reference using a single electrode (unipolar)Referential channels/acquisition of a reference using a single electrode (unipolar)8 bipolar + 8 AUX by means of ExG AUX Box
Input impedance10 MΩ (for DC) Switchable: 10 MΩ / 10 GΩ (for DC)10 MΩ (for DC)
Input noise≤ 1 μVpp≤ 1 μVpp≤ 2 μVpp
Common-mode rejection (CMR)≥ 90 dB≥ 110 dB≥ 100 dB
Lower cutoff frequency (high pass)0.016 Hz/10 s0 Hz in DC mode or 0.016 Hz/10 s in AC mode;
switchable between AC and DC modes
0 Hz in DC mode or 0.016 Hz/10 s in AC mode;
switchable between AC and DC modes
Filter typeFirst-order filter with 6 dB/octaveFirst-order filter with 6 dB/octaveFirst-order filter with 6 dB/octave
High-cutoff frequency (low-pass)/time constant250 Hz1000 Hz / 250 Hz (switchable for the resolutions 0.1 μV / 0.5 μV per bit)1000 Hz / 250 Hz (switchable for the resolutions 0.1 μV / 0.5 μV per bit)
Filter typeFifth-order Butterworth filter with 30 dB/octaveFifth-order Butterworth filter with 30 dB/octaveFifth-order Butterworth filter with 30 dB/octave
Measuring range±16.384 mV±3.28 mV / ±16.384 mV (switchable)±3.28mV / ±16.384 mV (switchable)
Resolution0.5 μV per bit0.1 μV / 0.5 μV per bit (switchable)0.1 μV / 0.5 μV per bit (switchable)
Power SupplyPowerPack (external rechargeable battery)PowerPack (external rechargeable battery)PowerPack (external rechargeable battery)
Power consumption (in operation)Max. 150 mAMax. 150 mAMax. 150 mA
Power consumption (in standby)Typically 7 mATypically 7 mATypically 7 mA
Amplitude accuracy±2%±2%±2%
Bit width of the A/D converter (EEG and AUX)16 bit16 bit16 bit
Sampling rate5 kHz per channel5 kHz per channel5 kHz per channel
DC offset tolerance±300 mV±300 mV±300 mV
Signal transmissionOptically coupled using duplex fiber optic cablesOptically coupled using duplex fiber optic cablesOptically coupled using duplex fiber optic cables
Operating time between chargesTypically 30 hours with one amplifier, 15 hours with two amplifiersTypically 30 hours with one amplifier, 15 hours with two amplifiersTypically 30 hours with one amplifier, 15 hours with two amplifiers
Dimensions (H x W x D)Approx. 68 mm x 160 mm x 187 mmApprox. 68 mm x 160 mm x 187 mmApprox. 68 mm x 160 mm x 187 mm
WeightApprox. 1.1 kgApprox. 1.1 kgApprox. 1.1 kg
Integrated impedance measurementPresent;
measurement includes ground electrode and reference electrode
Present;
measurement includes ground electrode and reference electrode
Present;
measurement includes ground electrode and reference electrode
Unlocking functionPresentPresentPresent
Locking of unused channelsPresentPresentPresent
Suitable for use in MR scanner roomYesYesYes
BatteryTechnical specifications
PowerPack
Number of amplifiers supplied1 or 2
Charging voltage9 V DC
Charging current670 mA
Rated capacity6,500 mAh
Output voltage5.6 V DC
Output current300 mA
Total Operating timeApprox. 4,000 hours
ChargingUsing external charger (Charger V9); only outside the scanner room
Charging timeApprox. 17 hours (with empty battery at room temperature)
Rechargeable battery typeLead gel rechargeable battery
Dimensions (H x W x D)Approx. 68 mm x 160 mm x 187 mm
WeightApprox. 1.9 kg
Electrical protection classII
Suitable for use in MR scanner roomYes
PowerPack charger V9
Input voltage range100 to 240 V AC, 50/60 Hz
Rated power consumptionMax. 145 mA
Output voltage9 V DC
Output currentMax. 670 mA
Suitable for use in MR scanner roomNo
WeightApprox. 130 g (without power adapter)
Interfaces for connecting the
amplifiers to the computer
Technical specifications
USB interface: USB2 Adapter (BUA)
Number of channels supported64 or 128 channels or two or four 32-channel amplifiers
USB port2.0
Power consumption with 64 channelsTypically 280 mA
Power consumption with 128 channelsTypically 400 to 500 mA
Trigger in16 bit; TTL (LVTTL) signals, 0 to +5 V (+ 3.3 V), max. 10 mA
Trigger connectionVia 26-pin HD D-Sub socket
Amplifier connectionVia duplex fiber optic cable
DimensionsApprox. 150 mm x 80 mm x 45 mm
WeightApprox. 260 g
AUX connectionVia 15-pin HD D-Sub socket
USB interface: dualUSB2 Adapter (dualBUA)
Number of channels supported Up to 256 channels or up to eight 32-channel amplifiers
Trigger in 16 bit; TTL (LVTTL) signals, 0 to +5 V (+ 3.3 V), max. 10 mA
Trigger connection Via 26-pin HD D-Sub socket (see Appendix D as of page 101)
Amplifier connection Via duplex fiber optic cable
Dimensions Twice the size of a USB2 Adapter
WeightApprox. 520 g (two USB2 Adapters) + approx. 140 g (dualBUA Adapter Cable)
MiscellaneousApplicable to all of the above
Medical devicesNo
CE markingsThe Brain Products GmbH confirms the electromagnetic compatibility (EMC) of these products according to the Directive 2014/30/ EU of the European Parliament and of the Council of 26 February 2014 on the harmonisation of the laws of the Member States relating to electromagnetic compatibility.

The Brain Products GmbH confirms the RoHS compliance of these products according to Directive 2011/65/EU of the European Parliament and the Council of 8 June 2011 on the restriction of the use of certain hazardous substances in electrical and electronic equipment (recast published in the Official Journal of the European Union on 1 July 2011) as well as all its amendments up to and including the Commission delegated directive (EU) 2015/863 of 31 March 2015 (published in the Official Journal of the European Union on 4 June 2015).

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