Full Content is available to subscribers

Subscribe/Learn More  >
Proceedings Article

Optical characterization of the Utah slant optrode array for intrafascicular infrared neural stimulation

[+] Author Affiliations
T. V. F. Abaya, M. Diwekar, S. Blair, P. Tathireddy, L. Rieth, G. A. Clark, F. Solzbacher

The Univ. of Utah (USA)

Proc. SPIE 8207, Photonic Therapeutics and Diagnostics VIII, 82075M (February 9, 2012); doi:10.1117/12.907375
Text Size: A A A
From Conference Volume 8207

  • Photonic Therapeutics and Diagnostics VIII
  • San Francisco, California, USA | January 21, 2012

abstract

We present an early-generation Utah Slant Optrode Array (USOA) for infrared (IR) neural stimulation. Intrafascicular IR stimulation with the early prototype in the cat sciatic nerve produced highly selective and artifact-free responses, which outperformed extraneural IR stimulation. We characterized the light delivery and loss mechanisms of the device in order to facilitate design optimization. Fabrication of the USOA takes advantage of the extensive research in the development of the Utah Slant Electrode Array (USEA). An undoped (ρ > 20 ω ρ cm) c-Si (100) substrate was used to produce a 10 x 10 array of optrodes with lengths from 0.5 mm to 1.5 mm in a 400-μm pitch. This substrate is able to transmit IR (λ > 1.1μm) with negligible absorption losses. The optrodes were coupled to the laser source via fibers of different core diameters through in-coupling interfaces of varying refractive indices. The effect of these factors on optrode transmission efficiency was investigated. At 1550nm, transmittance for a butt-coupled 50-μm multimode fiber through a medium of index n = 1.66 was measured as 34.7%, which was the maximum value obtained. When the refractive index of the intervening medium was lowered, transmission decreased according to Fresnel reflection theory. Above 100-μm core size, transmitted power decreases by 40% with each doubling of the fiber core diameter. Transmission was also found to be dependent on the optrode length, where shorter and more tapered optrodes provided less output power. The results suggest that Fresnel, coupling, and radiation losses are the primary loss mechanisms.

© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Citation

T. V. F. Abaya ; M. Diwekar ; S. Blair ; P. Tathireddy ; L. Rieth, et al.
"Optical characterization of the Utah slant optrode array for intrafascicular infrared neural stimulation", Proc. SPIE 8207, Photonic Therapeutics and Diagnostics VIII, 82075M (February 9, 2012); doi:10.1117/12.907375; http://dx.doi.org/10.1117/12.907375


Access This Proceeding
Sign in or Create a personal account to Buy this proceeding ($15 for members, $18 for non-members).

Figures

Tables

NOTE:
Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging & repositioning the boxes below.

Related Book Chapters

Topic Collections

Advertisement
  • Don't have an account?
  • Subscribe to the SPIE Digital Library
  • Create a FREE account to sign up for Digital Library content alerts and gain access to institutional subscriptions remotely.
Access This Proceeding
Sign in or Create a personal account to Buy this proceeding ($15 for members, $18 for non-members).
Access This Proceeding
Sign in or Create a personal account to Buy this article ($15 for members, $18 for non-members).
Access This Chapter

Access to SPIE eBooks is limited to subscribing institutions and is not available as part of a personal subscription. Print or electronic versions of individual SPIE books may be purchased via SPIE.org.