A FRONT-END STAGE FOR NEURAL SIGNAL RECORDING BASED ON A SIGMA-DELTA MODULATOR Topics: Artificial Limbs; Biomedical Instrumentation; Brain-Computer Interfaces; Implantable Electronics; Low-Power Design; Microelectronics In Proceedings of the International Conference on Biomedical Electronics and Devices - Volume 0BIOSTEC, 207-212, 2012 , Vilamoura, Algarve, Portugal