Comparison of control algorithms for a MEMS-based adaptive optics scanning laser ophthalmoscope

We compared four algorithms for controlling a MEMS deformable mirror of an adaptive optics (AO) scanning laser ophthalmoscope. Interferometer measurements of the static nonlinear response of the deformable mirror were used to form an equivalent linear model of the AO system so that the classic integrator plus wavefront reconstructor type controller can be implemented. The algorithms differ only in the design of the wavefront reconstructor. The comparisons were made for two eyes (two individuals) via a series of imaging sessions. All four controllers performed similarly according to estimated residual wavefront error not reflecting the actual image quality observed. A metric based on mean image intensity did consistently reflect the qualitative observations of retinal image quality. Based on this metric, the controller most effective for suppressing the least significant modes of the deformable mirror performed the best.

[1]  Thomas G. Bifano,et al.  Micromachined deformable mirrors for dynamic wavefront control , 2004, SPIE Optics + Photonics.

[2]  A. Hendrickson,et al.  Human photoreceptor topography , 1990, The Journal of comparative neurology.

[3]  Curtis R Vogel,et al.  Modeling, simulation, and open-loop control of a continuous facesheet MEMS deformable mirror. , 2006, Journal of the Optical Society of America. A, Optics, image science, and vision.

[4]  David Le Mignant,et al.  Performance of the Keck Observatory adaptive-optics system. , 2004, Applied optics.

[5]  B. Singer,et al.  Improvement in retinal image quality with dynamic correction of the eye's aberrations. , 2001, Optics express.

[6]  J. Herrmann,et al.  Least-squares wave front errors of minimum norm , 1980 .

[7]  D R Williams,et al.  Supernormal vision and high-resolution retinal imaging through adaptive optics. , 1997, Journal of the Optical Society of America. A, Optics, image science, and vision.

[8]  Brent L Ellerbroek,et al.  Efficient computation of minimum-variance wave-front reconstructors with sparse matrix techniques. , 2002, Journal of the Optical Society of America. A, Optics, image science, and vision.

[9]  P. Artal,et al.  Adaptive-optics ultrahigh-resolution optical coherence tomography. , 2004, Optics letters.

[10]  Norberto López-Gil,et al.  Statistical description of wave-front aberration in the human eye. , 2002, Optics letters.

[11]  Donald T. Gavel.  Suppressing anomalous localized waffle behavior in least-squares wavefront reconstructors , 2003, SPIE Astronomical Telescopes + Instrumentation.

[12]  D. Williams,et al.  Monochromatic aberrations of the human eye in a large population. , 2001, Journal of the Optical Society of America. A, Optics, image science, and vision.

[13]  Austin Roorda,et al.  Applications of Adaptive Optics Scanning Laser Ophthalmoscopy , 2010, Optometry and vision science : official publication of the American Academy of Optometry.

[14]  Vincent Michau,et al.  Adaptive optics: interaction matrix measurements and real time control algorithms for the COME-ON project , 1990, Other Conferences.

[15]  D.P. Looze.  Minimum variance control structure for adaptive optics systems , 2005, Proceedings of the 2005, American Control Conference, 2005..

[16]  T. Hebert,et al.  Adaptive optics scanning laser ophthalmoscopy. , 2002, Optics express.

[17]  A. Roorda,et al.  Theoretical modeling and evaluation of the axial resolution of the adaptive optics scanning laser ophthalmoscope. , 2004, Journal of biomedical optics.

[18]  Norberto López-Gil,et al.  Ocular wave-front aberration statistics in a normal young population , 2002, Vision Research.

[19]  A. Roorda,et al.  MEMS-based adaptive optics scanning laser ophthalmoscopy. , 2006, Optics letters.