Control measurements for lasers in physiotherapy.

Objectives: In physical rehabilitation, is diffused the skin irradiation with near infrared laser at a fluence below 140 J/cm2, achieving a bio-stimulating effect that is due to the absorption of radiation in mitochondria rather than the simple heating of tissues.

Methods: In order to deliver radiation without thermal damage of the skin, are used radiation pulses which duration does not allow heat accumulation and propagation far from the irradiated target; this requires laser sources with average power below 10 W implying a safety classification as "potentially dangerous for eye and skin", or "class 4" according to the applicable international standards. In this paper, 6 laser therapy devices, of 5 different manufactures and models have been analyzed from the point of view of actual radiation output and user safety.