29 Dec '15, 6pm
Amplifying the Body’s Own Electricity https://t.co/IxVrUWyDTQ
In the block diagram above, three connections are used to pick up the small electrical signature of the body’s muscles. Two leads are connected directly to the inputs of an instrumentation amplifier. You’ll remember from my previous video, Instrumentation amplifiers are special because of their high impedance and low noise characteristics. Often it is not the highest gain block in a chain, its primary job is to dig the signal out from the environment and give it its initial amplification and buffering so that following stages can further amplify a clean signal easily. The instrumentation amp is also good at stripping out a signal, whether noise or just an offset (the common mode part), and amplifying only the difference (the differential). That is exactly what’s going on here.