High-intensity laser for acupuncture-like stimulation.

The insertion of needles into specific parts of the body was shown to provide analgesic and therapeutic effects. In this study, we tested the analgesic effects of high-intensity infrared laser for acupuncture-like stimulation. Twelve adult Sprague-Dawley rats weighing 230 to 250 g were randomly assigned to laser, needle, or restraint groups. Stimulation was directed to the meridian point Taixi (KI 3) for 10 min. For laser stimulation, a pulsed Er:YAG system was used. The laser settings were adjusted to provide a focal raise in the skin temperature to about 45 degrees C. The anti-nociceptive effect was evaluated by the tail-flick test. Both needling and laser stimulation significantly increased the tail-flick latency. Peak needling effect was observed immediately after treatment, while laser stimulation was effective both immediately and 45 min after treatment. High-intensity laser stimulation may be used alternatively or in combination with conventional acupuncture needling for pain relief.