In-Vitro and In-Vivo Electrical Characteristics of a Penetrating
Microelectrode Array for Optic Nerve Electrical Stimulation

doi:10.1007/s12204-011-1198-0

Abstract

Abstract: Abstract: The Chinese C-Sight team aims to restore
vision to blind patients by means of stimulating the optic nerve
with a penetrating microelectrode array. A biocompatible,
implantable microwire array was developed having four
platinum-iridium shafts, each 100 µm in diameter. This
penetrating microwire array is described in this paper, including
its fabrication techniques and its in-vitro electrical
characteristics. Every set of four shafts was spaced 0.4 mm from
center to center, comprising two short shafts that were 0.3 mm long
and two that were 0.9 mm long. This design was intended to
stimulate ganglion cell axons at different depths within the optic
nerve. In-vitro electrochemical impedance testing results showed
that the impedance at 1 kHz ranged from 8 to 10 kΩ at room
temperature. The voltage responses of the arrays to current pulse
stimulation indicated a charge-injection capacity of
210 µC/cm2. Finally, in-vivo acute animal experiments
showed that the amplitude of the electrically evoked potentials
(EEPs) measured in primary visual cortex could be as large as
100 μV upon direct stimulation of the optic nerve.

Key words:

optic nerve visual prosthesis| platinum-iridium
(Pt/Ir) microelectrode| charge injection capacity| impedance

摘要： Abstract: The Chinese C-Sight team aims to restore
vision to blind patients by means of stimulating the optic nerve
with a penetrating microelectrode array. A biocompatible,
implantable microwire array was developed having four
platinum-iridium shafts, each 100 µm in diameter. This
penetrating microwire array is described in this paper, including
its fabrication techniques and its in-vitro electrical
characteristics. Every set of four shafts was spaced 0.4 mm from
center to center, comprising two short shafts that were 0.3 mm long
and two that were 0.9 mm long. This design was intended to
stimulate ganglion cell axons at different depths within the optic
nerve. In-vitro electrochemical impedance testing results showed
that the impedance at 1 kHz ranged from 8 to 10 kΩ at room
temperature. The voltage responses of the arrays to current pulse
stimulation indicated a charge-injection capacity of
210 µC/cm2. Finally, in-vivo acute animal experiments
showed that the amplitude of the electrically evoked potentials
(EEPs) measured in primary visual cortex could be as large as
100 μV upon direct stimulation of the optic nerve.

关键词:

optic nerve visual prosthesis| platinum-iridium
(Pt/Ir) microelectrode| charge injection capacity| impedance

CLC Number:

R 318

SUI Xiao-hong (隋晓红), . In-Vitro and In-Vivo Electrical Characteristics of a Penetrating
Microelectrode Array for Optic Nerve Electrical Stimulation[J]. Journal of shanghai Jiaotong University (Science), 2011, 16(5): 614-619.

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