An implantable optical stimulation delivery system for actuating an excitable biosubstrate

The use of light-activated modulation techniques, such as optogenetics, is growing in popularity for enabling basic neuroscience research. It is also being explored for advancing more applied applications like therapeutic neuromodulation. However, current hardware systems are generally limited to acute measurements or require external tethering of the system to the light source. This paper presents an implantable prototype for use in techniques that modulate neurological state through optically-activated channels and compounds. The prototype system employs a three chip custom IC architecture to manage information flow into the neural substrate, while also handling power dissipation and providing a chronic barrier to the tissue interface. In addition to covering the details of the IC architecture, we discuss system level design constraints and solutions, and in-vitro test results using our prototype system with an optogenetic model. Potential technical limitations for the broader adoption of these techniques will also be considered.