Ubiquitous monitoring of physiological parameters will allow an early detection of the degradation of an individual's health condition. Yet, it is still a challenge to record high-quality signals with small lightweight devices outside the hospital. In this book we investigate methods to improve amplifiers for bioelectric events such as ECG and EEG. We focus on noise-optimization, power minimization, wearability and the reduction of motion artifacts. An important topic are active electrodes and their application.