An Implantable Retinal Stimulator Design for Long-term Animal Experiments

an implantable stimulator, which provides continuous electrical stimulation and an external component, which provides preset stimulation parameters and power to the implanted stimulator via a paired RF (radio frequency) coil. A rechargeable internal battery and a parameter memory part were introduced to the implantable stimulator to avoid use of the external component during the stimulation cycles. The same inductive coil pair was used to pass the parameter data and to recharge the battery. To separate the stimulation mode and the battery recharging mode, a switch circuit is used. The implantable stimulator was implemented with IC chips and the electronics except the stimulation electrodes were hermetically packaged in a biocompatible metal case.