Steffen Kibbel

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A light-sensitive, externally powered microchip was surgically implanted subretinally near the macular region of volunteers blind from hereditary retinal dystrophy. The implant contains an array of 1500 active microphotodiodes ('chip'), each with its own amplifier and local stimulation electrode. At the implant's tip, another array of 16 wire-connected(More)
PURPOSE The perception of 11 persons blinded by hereditary retinal degeneration elicited by a subretinally implanted 16-electrode array used for light-independent direct stimulation of the retina is described. This device is part of the Tübingen retina implant, which also employs a light-sensitive, multiphotodiode array (MPDA). The ability to reliably(More)
Eleven patients received subretinal implants, powered and controlled via a subdermal cable ending in a thin intraocular foil, placed transsclerally between the retinal pigment epithelium and the neuroretina. The tip of this foil carries two distinct arrays, a Multiphotodiode Array (MPDA) with 1500 electrodes, each electrode being controlled by an adjacent(More)
Our group has developed a subretinal microphotodiode array for restoration of vision. In a clinical pilot study the array has been implanted in 11 patients suffering from photoreceptor degenerations. Here we present promising results from some of those patients where the retinal tissue above the chip was functional and the implant fulfilled its expected(More)
For neural stimulation, reliable high density charge transfer into tissue is required. One electrode material for these applications is titanium nitride (TiN). In this paper, a method for lifetime analysis of TiN electrodes is discussed. Our method significantly differs from open literature. The tests were run for much longer durations. Special attention(More)
Retina Implants have the purpose to restore visual perception in blind patients suffering from retinitis pigmentosa (RP) and eventually also age-related macular degeneration (AMD). Electrical stimulation of the remaining retinal nerve fibre layers leads to visual sensations (phosphenes) [1, 2]. Our retina implant consisting of a light sensitive CMOS chip(More)
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