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Robert Califf, John D. Rutherford
Circulation, Volume 138, pp 1765-1770; doi:10.1161/circulationaha.118.037900

Jackson T. Wright, Robert M. Carey, Shari D. Bolen
Circulation, Volume 138, pp 1774-1776; doi:10.1161/circulationaha.118.036981

Paul K. Whelton, Robert M. Carey, Wilbert S. Aronow, Donald E. Casey, Karen J. Collins, Cheryl Dennison Himmelfarb, Sondra M. DePalma, Samuel Gidding, Kenneth A. Jamerson, Daniel W. Jones, et al.
Circulation, Volume 138; doi:10.1161/cir.0000000000000597

Ali Eshaghian Dorche, Amir Hossein Hosseinnia, Ali Asghar Eftekhar, Ali Adibi
Journal of Nanophotonics, Volume 12; doi:10.1117/1.jnp.12.046008

Yingyue Xu, Nan Xia, Michelle Lim, Xiaodong Tan, Minh Ha Tran, Erin Boulger, Fei Peng, Hunter Young, Christoph Rau, Alexander Rack, et al.
Neurophotonics, Volume 5; doi:10.1117/1.nph.5.4.045002

Abstract: An emerging method in the field of neural stimulation is the use of photons to activate neurons. The possible advantage of optical stimulation over electrical is attributable to its spatially selective activation of small neuron populations, which is promising in generating superior spatial resolution in neural interfaces. Two principal methods are explored for cochlear prostheses: direct stimulation of nerves with infrared light and optogenetics. This paper discusses basic requirements for developing a light delivery system (LDS) for the cochlea and provides examples for building such devices. The proposed device relies on small optical sources, which are assembled in an array to be inserted into the cochlea. The mechanical properties, the biocompatibility, and the efficacy of optrodes have been tested in animal models. The force required to insert optrodes into a model of the human scala tympani was comparable to insertion forces obtained for contemporary cochlear implant electrodes. Side-emitting diodes are powerful enough to evoke auditory responses in guinea pigs. Chronic implantation of the LDS did not elevate auditory brainstem responses over 26 weeks. 1.Introduction1.1.Cochlear Implants and Their ChallengesCochlear implants (CIs) are considered one of the most successful neural prostheses. Today about 350,000 individuals with severe-to-profound hearing loss have received a CI to restore some of their hearing. However, the performance of individual users varies largely. While some patients are able to communicate over the phone in different languages, others receive little benefit from CIs. For all CI users, noisy listening environments and music perception constitute a challenge.12.–3 It has been argued that performance could be improved by reducing the interaction between neighboring CI electrode contacts, subsequently creating more independent channels for stimulation. More spatially selective stimulation with electric current can be achieved through multipolar stimulation, where multiple electrode contacts are used to narrow the current field.45.6.–7 Another approach to increasing the number of different pitch percepts is called current steering.89.–10 In this approach, neighboring electrodes are used simultaneously to “steer” the current to selected neuron populations between the two contacts. However, this technique does not introduce more independent channels for parallel stimulation.1011.12.13.–141.2.Optical StimulationMore recently, the use of photons has been suggested as an approach to evoke responses from small populations of neurons,1516.17.–18 because optical radiation can be delivered spatially selectively.19,20 It is anticipated that optical stimulation decreases interactions between neighboring channels, allowing for the development of neural prostheses with enhanced neural fidelity. Two methods for direct neural stimulation with light are currently considered: optogenetics and infrared neural...
Manoharan Prabukumar, Shrutika Sawant, Sathishkumar Samiappan, Loganathan Agilandeeswari
Journal of Applied Remote Sensing, Volume 12; doi:10.1117/1.jrs.12.046010

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