Novel wavelengths for laser nerve stimulation

Background Laser light is known to stimulate nerves. This study investigated alternative wavelengths for nerve stimulation. Materials and Methods The sciatic nerves of rats were irradiated with four different lasers—a Ho:YAG (2100 nm), a Yb:glass fiber laser (1495 nm) and diode lasers (1450 nm and 1540 nm). Results All lasers evoked a visible leg twitch response, and electromyography confirmed muscle activation. The Yb:glass laser at 1495 nm delivered through a single mode fiber was found to be the most effective stimulus. The stimulation threshold for a 2 millisecond pulse from the Yb:glass laser was determined to be 3.7±2.8 mJ/cm2. Conclusions The Yb:glass laser has the potential for use in neurostimulation, as an alternative to electrical stimulation. Lasers Surg. Med. 42:69–75, 2010. © 2009 Wiley‐Liss, Inc.