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Journal of Biomedical Optics • Open Access

Application of infrared light for in vivo neural stimulation
Author(s): Jonathon D. Wells; Chris Kao; E. Duco Jansen; Peter E. Konrad; Anita Mahadevan-Jansen

Paper Abstract

A novel method for damage-free, artifact-free stimulation of neural tissue using pulsed, low-energy infrared laser light is presented. Optical stimulation elicits compound nerve and muscle potentials similar to responses obtained with conventional electrical neural stimulation in a rat sciatic nerve model. Stimulation and damage thresholds were determined as a function of wavelength using a tunable free electron laser source (=2 to 10 µm) and a solid state holmium:YAG laser (=2.12 µm). Threshold radiant exposure required for stimulation varies with wavelength from 0.312 J/cm2 (=3 µm) to 1.22 J/cm2 (=2.1 µm). Histological analysis indicates no discernable thermal damage with suprathreshold stimulation. The largest damage/stimulation threshold ratios (>6) were at wavelengths corresponding to valleys in the IR spectrum of soft tissue absorption (4 and 2.1 µm). Furthermore, optical stimulation can be used to generate a spatially selective response in small fascicles of the sciatic nerve that has significant advantages (e.g., noncontact, spatial resolution, lack of stimulation artifact) over conventional electrical methods in diagnostic and therapeutic procedures in neuroscience, neurology, and neurosurgery.

Paper Details

Date Published: 1 November 2005
PDF: 12 pages
J. Biomed. Opt. 10(6) 064003 doi: 10.1117/1.2121772
Published in: Journal of Biomedical Optics Volume 10, Issue 6
Show Author Affiliations
Jonathon D. Wells, Vanderbilt Univ. (United States)
Chris Kao, Vanderbilt Univ. (United States)
E. Duco Jansen, Vanderbilt Univ. (United States)
Peter E. Konrad, Vanderbilt Univ. (United States)
Anita Mahadevan-Jansen, Vanderbilt Univ. (United States)

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