Design of an Optically Activated One-channel Epi-retinal Implant and Its Chronical Implantation and Testing in Cats
Schanze T.1, Hesse L.2,5, Stieglitz T.3, Lau C.4, Rentzos A.1, Haberer W.3, Richter H. A.4
1NeuroPhysics Grp, 5Eye Clinic, University Marburg; 2Eye Clinic, Heilbronn; 3FhG-IBMT, St. Ingbert; 4Chair of Pathology, University Aachen
Purpose: A retina implant for restoring basic visual perception in patients that are blind due to photoreceptor loss should be biocompatible and robust. We designed a simple epi-retinal implant and started its implantation and testing in anaesthetized cats.
Method: An optically activated one-channel retina stimulator has been designed for the proof of principle to use polyimide substrate with integrated platinum electrodes and a combined parylene/silicone encapsulation to protect electronic components against ions, moisture and mechanical damage. Four PIN-photodiodes were electrically connected on a polyimide substrate in series to reach a voltage that might be sufficiently high to drive a current for epi-retinal ganglion cell stimulation. The diodes were connected by a polyimide cable lead with two polyimide-platinum electrodes. We used short infrared light impulses for implant activation. Prior to implantation the implants were tested in-vitro. For implantation we performed a lentectomy and a complete vitrectomy in five cats. The silicone encapsulated part was sulcus fixated and the film-elect
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