What type of amplifiers are used for recording biological signals?

Differential amplifiers are specifically designed to enhance the acquisition of biological signals by effectively amplifying the difference between two input signals while rejecting any noise or interference present in both signals. This characteristic is critical when recording biological signals like those from EEG, ECG, or EMG, as these signals can be quite small in amplitude and often contaminated by various sources of electrical noise.

The use of differential amplifiers ensures that common-mode noise—such as electromagnetic interference from electronic devices or other environmental factors—is minimized, allowing for a clearer and more accurate representation of the biological signal of interest. This is particularly important in clinical settings where precise measurements are required for diagnosis and treatment planning.

While the other types of amplifiers mentioned can be used in signal processing, they do not possess the same level of effectiveness in rejecting common-mode noise and are not typically used exclusively for recording biological signals.