Low-Power Communication for an Implanted Intracortical Visual Prosthesis

Assisting visually impaired people to see again using technology is quite challenging, especially for cases where most of the visual pathway is damaged. The only viable option is to stimulate the visual cortex directly. Sending the stimulation data to electrodes on the visual cortex is preferably done wirelessly to avoid infections and to ease mobility. The receiver on the implant poses a challenge in design, as the power supply is limited. In this paper, vital system requirements for this communication link are discussed. A low power system-level approach is presented which seeks to avoid power hungry components. This leads to the consideration of a bandpass sampled phase shift keying scheme via an inductive link. We propose a non-coherent digital demodulator, which relaxes the need for low phase noise oscillators which consume more power and, also avoids the use of phase locks loops. The overall communication system has a potential to deliver stimulation data to the implant side in the presence of simultaneous power transfer and reception of recorded data from the brain.