B C Basinger et al 2009 J. Neural Eng. 6 055006 doi:10.1088/1741-2560/6/5/055006
B C Basinger1,2, A P Rowley2,3, K Chen1,2, M S Humayun1,2,3,4 and J D Weiland1,2,4,5
Show affiliationsEpiretinal prostheses used to treat degenerative retina diseases apply stimulus via an electrode array fixed to the ganglion cell side of the retina. Mechanical pressure applied by these arrays to the retina, both during initial insertion and throughout chronic use, could cause sufficient retinal damage to reduce the device's effectiveness. In order to understand and minimize potential mechanical damage, we have used finite element analysis to model mechanical interactions between an electrode array and the retina in both acute and chronic loading configurations. Modeling indicates that an acute tacking force distributes stress primarily underneath the tack site and heel edge of the array, while more moderate chronic stresses are distributed more evenly underneath the array. Retinal damage in a canine model chronically implanted with a similar array occurred in correlating locations, and model predictions correlate well with benchtop eyewall compression tests. This model provides retinal prosthesis researchers with a tool to optimize the mechanical electrode array design, but the techniques used here represent a unique effort to combine a modifiable device and soft biological tissues in the same model and those techniques could be extended to other devices that come into mechanical contact with soft neural tissues.
87.80.-y Biophysical techniques (research methods)
42.66.Ct Anatomy and optics of eye
02.70.Dh Finite-element and Galerkin methods
87.19.R- Mechanical and electrical properties of tissues and organs
Instrumentation and measurement
Issue 5 (October 2009)
Received 28 October 2008, accepted for publication 9 June 2009
Published 1 September 2009
B C Basinger et al 2009 J. Neural Eng. 6 055006
Kenneth A. Marsh et al. 2010 ApJ 709 L158
B. Cherinka et al. 2009 The Astronomical Journal 138 1714
M. Okabayashi et al 2005 Nucl. Fusion 45 1715
E. Lundh 2008 EPL 84 10007
M V Georgievsky 2009 Environ. Res. Lett. 4 045017
L. Homer et al. 2001 The Astronomical Journal 122 2627
Sikina Jinnah et al 2009 Environ. Res. Lett. 4 034003
U. Heiter and R. E. Luck 2003 The Astronomical Journal 126 2015
Tadayuki Takahashi et al. 2009 ApJ 697 592