Laser

Lasers Med Sci (2007) 22: 37–41 DOI 10.1007/s10103-006-0408-8

ORIGINA L ARTI CLE

J. L. Zeredo . K. M. Sasaki . K. Toda

High-intensity laser for acupuncture-like stimulation

Received: 28 April 2006 / Revised: 20 July 2006 / Accepted: 4 September 2006 / Published online: 21 November 2006 # Springer-Verlag London Limited 2006

Abstract The insertion of needles into specific parts ofthe 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 pulsedEr: YAG system was used. The laser settings were adjusted to provide a focal raise in the skin temperature to about 45°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 minafter treatment. High-intensity laser stimulation may be used alternatively or in combination with conventional acupuncture needling for pain relief. Keywords Lasers . Acupuncture . Analgesia . Rats

Introduction
Acupuncture is one of the most widely spread components of the traditional Chinese medicine. It involves the stimulation of specific points of the body with fine needles. Suchstimulation, according to traditional beliefs, would help reestablish the flow of the body’s vital energy (“qi”), and by doing so, relieve pain and cure ailments. Laser acupuncture shares the same principles of the traditional
J. L. Zeredo (*) . K. M. Sasaki . K. Toda Division of Integrative Sensory Physiology, Department of Developmental and Reconstructive Medicine, Graduate School of BiomedicalSciences, Nagasaki University, 1-7-1 Sakamoto, Nagasaki, 852-8588, Japan e-mail: jorge@nagasaki-u.ac.jp Tel.: +81-95-8497638 Fax: +81-95-8497639

acupuncture but uses low-level, non-thermal laser irradiation instead of needles [1]. Its development was probably inspired from low-level laser therapy, which is believed to stimulate wound healing and relieve pain. Other than low-level laser irradiation, andof course the traditional mechanical stimulation of needles, many different kinds of stimulation were tried over acupuncture points. For instance, blunt pressure, heat, cold, electrical currents, and chemical agents [2–7]. Among all these forms of stimulation, heat has probably been one of the earliest, and may have even preceded that of needles [8]. From ancient textbooks, it is said that heattherapy would serve as an approach to supplement qi when it was considered depleted, while needling would drain qi when full [9]. Traditionally, heat was delivered by burning moxa wool over selected acupuncture points. Moxa is made of Artemisia vulgaris, an aromatic herb also known as mugwort. Moxa application can be either direct or indirect. When moxa is burned directly on the skin, twotechniques may be followed: scarring and non-scarring [10]. In the scarring technique, burning moxa is placed on the acupuncture point continuously, causing a local burn with blister formation, which leads to healing with subsequent scar formation. In the non-scarring technique, the patient feels scorching heat but no blisters should be formed, and there is no scar formation. The non-scarring technique hasactually a larger range of indications and is by far the most common form of heat therapy. Moxa is sometimes burned not directly on the skin, but indirectly over herbal patches, ginger slices, or mounds of salt, among others [10]. Some modern practitioners also use lamps and other heat sources instead of burning moxa. Scientific assessment of the traditional techniques and their outcomes,...