While the human brain may make us what we are, our sensory systems are our windows and doors to the world. In fact they are our ONLY windows and doors to the world. So when one of these systems fails, the corresponding part of our world is no longer accessible to us. Recent advances in engineering have made it possible to replace sensory systems by mechanical and electrical sensors, and to couple those sensors electronically to our nervous system. While to many this may sound futuristic and maybe even a bit scary, it can work magically. For the auditory system, so called “cochlea implants” have given thousands of patients who were completely deaf their hearing back, so that they can interact and communicate freely again with their family and friends. Many research groups are also exploring different approaches to retinal implants, in order to restore vision to the blind. And in 2010 the first patient has been implanted with a “vestibular implant”, to alleviate defects in his balance system.
The wikibook “Sensory Systems” wants to present our sensory systems from an engineering and information processing point of view. On the one hand, this provides some insight in the sometimes spectacular ingenuity and performance of our senses. On the other hand, it provides some understanding of how our senses transduce external information into signals that our central nervous system can work with, and how – and how well - this process can be replaced by technical components.