The device connects directly to EEG electrodes, which means that in the presence of a sufficiently severe failure it could potentially drive current across the

The device connects directly to EEG electrodes, which means that in the presence of a sufficiently severe failure it could potentially drive current across the brain. There's also no obvious galvanic isolation (transformers, etc., like an Ethernet PHY) in the pictured design, which is especially concerning since it means the device could potentially provide a path to ground (again, through the brain!) in the case of a miswired or damaged appliance exposing mains voltage - which sounds like a rare concern, but has actually happened to me once; I was fortunate that the consequent cross-chest shock was only deeply unpleasant, and not lethal, which it easily might have been if I hadn't broken the connection by falling over. At an absolute minimum, I'd expect to see clear warnings to only use this device while it was powered from battery and with no wired connections to a power supply or to any other device plugged into the mains. In that condition, it should be relatively safe; in any other, I wouldn't think of using it and would recommend no one else do, either.