EEG amplifier / EMG
The Refa is a 72- or 136-channel stationary system for measuring EEG or HD EMG. The Refa always includes unipolar electrophysiological inputs (ExG) but can also include four bipolar electrophysiological inputs (BIP) and four auxiliary inputs (AUX).
The Refa includes TMSi's proprietary TAS2 (True Active Signal Shielding) technology for clean signals and data completely free of mains interference and cable movement artifacts. It does not include hardware filters (other than anti-aliasing) so the raw data is always available and quick recovery ensured. The ExG inputs are configured as a reference amplifier: all channels are amplified against the average of all connected inputs. The BIP inputs are used to measure two physiological signals differentially to each other. Using ExG and BIP channels, signals like EEG, EMG, ECG, EOG, EGG, etc. can be measured. The AUX inputs can be used for measuring sensor signals like temperature, pH, respiration, movement, force, angle, etc. Each of these channels has a +5 V and -5 V supply in order to accommodate active sensors or sensor modules.
The Refa system can be delivered with 24, 32, 40, 72 or 136 channels (The Refa High Rate is available with 8, 16, 32, 40 and 72 channels). It is also possible to cascade two Refa's, resulting in a total channel count of 272 channels.The Refa is delivered including an external power supply which plugs into the mains socket. The Refa is connected to a PC by means of a bi-directional optical fiber.