Isolation amplifiers electrically isolate input and output signals, often by inductive couplings. Isolation amplifiers or iso-amps may be used to protect components from potentially dangerous voltages or to amplify low-level analog signals in applications with multiple channels. Isolation amplifiers work with systems where a sensor or input is separated from the system supplying data. These isolation barriers are useful in protecting sensitive sensors from high voltages. A good example of this type of amplifier isolation exists in medical devices that use electricity to get physical data from patients, such as an electrocardiograph (ECG) or an electroencephalograph (EEG).