EA136 Amplifier System
Designed to amplify 136 EEG channels in the MRI (Magnetic Resonance Imaging) and MEG (Magnetic electroencephalogram) recording environments, the EA136 amplifier can be used to record quality EEG data without interfering with these extremely sensitive systems. The system consists of two parts: a 136-channel preamplifier (shown below) and a corresponding 136 channel-medical grade isolation unit (shown below). As MRI and MEG systems are highly sensitive to electromagnetic interference (EMI), any EEG recording device used in conjunction with these systems should have a minimal EMI footprint. It must also be able to amplify electrical signals from the scalp and verify electrical contact or electrode impedance. The EA136 preamplifier does this with ultra low-noise amplifiers. The preamplifier is placed in close proximity to the subject keeping the lead path as short as possible. The EEG signal is then amplified and transmitted to a corresponding EA136 isolation unit located adjacent to a wave guide or penetration panel to the MRI/MSR room. Outputs from the Isolation unit are then filtered for RF and attached to the data acquisition unit positioned outside the MRI/MSR room. This design removes all high-speed clock signals typically associated with converting the analog EEG signals to digital values from the recording environment.
The EA136 Pre-amp system can be used with our isolation unit and data acquisition units or as a stand-alone upgrade to boost the performance of older systems. Amplifiers have PTP noise of 0.89 uV (1-100Hz) 3uV/C drift for outstanding DC and noise performance. Input impedance is 1 GΩ; offset potential tolerance is + 40mV (requires Ag/AgCl sintered electrodes). Factory configuration is 64 monopolar, 4 bipolar channels for total of 68; second board provides 68 channels for total of 136.
EA136 Isolation Unit
The Isolation Unit is designed to place the early stage amplification as close to the subject as possible which makes it ideal for noise-sensitive and difficult recording environments. Subject isolation is provided in a second unit. All 136 channels are optically isolated to 5 kV. Input voltage: 115(120)/230(240) VAC. Input current 2A.
EA136 Preamplifier Location
The pre-amplifier is designed to be as close as possible to the subject. Each wire in the cap is individually shielded up to the electrode. This is optimal for recordings made in the bore of the scanner. The preamplifier is made from non-ferrous material and has a gain of 35.
Sands Research can partner with you in designing and customizing equipment that meets your specific and unique needs. Contact us for more information.
SANDS RESEARCH INC. 955 N Resler 104-113
El Paso, TX 79912
Phone 915.787.0254 FAX 915.201.2544