Analog front-end circuits play a critical role in health monitoring and biosensing systems by directly interfacing with various types of electrodes and sensors. Although providing the basic functionality of reading out the analog signals from the electrodes and sensors is simple and straightforward, realizing robust readout interfaces is extremely challenging due to the presence of diverse disturbing factors such as powerline interferences, motion artifacts, stimulation artifacts, and sensor variations, depending on the application and usage scenario. In this talk, advanced analog front-end design techniques developed to address such challenges are introduced and discussed.