Radiant power determination of low-level laser therapy equipment and characterization of its clinical use procedures.
OBJECTIVE
The main objectives of this study were to characterize low-level laser therapy (LLLT) and the physical therapy clinical procedures for its use.


BACKGROUND
There are few scientific studies that characterize the calibration of LLLT equipment.


METHODS
Forty lasers at 36 physical therapy clinics were selected. The equipment was characterized through data collected from the owner manuals, direct consultation with the manufacturers, and a questionnaire answered by the users. A digital potency analyzer was used to calibrate released mean potency. Qualitative data were presented throughout the descriptive statistics and quantitative data were analyzed by the Wilcoxon/Kruskal-Wallis and Fisher tests (significance, p < 0.05).


RESULTS
The laser equipment was either AsGa (70.5%) or HeNe (23.5%), and 60% was analog and acquired over 5 years ago. The majority of the equipment was used 10-15 times per week and the most frequent density level used was 2 to 4 J/cm(2). Protective goggles were available in only 19.4% of the clinics evaluated. The association between the analyzed categories demonstrated that a lower mean potency was correlated both with equipment acquired over 5 years ago and analog technology. The determined mean potency was lower than the one claimed by the manufacturer (p < 0.05). In 30 cases, the analyzed equipment presented a potency between 3 microW and 5.6 mW; in three cases, the potency was >25 mW; and in seven cases, potency was nonexistent.


CONCLUSIONS
The analyzed equipment was out-dated and periodical maintenance was not conducted, which was reflected in the low irradiated potency.
Guirro
Rinaldo Roberto de Jesus
RR
Department of Biomechanics, Medicine and Rehabilitation of the Locomotor System, School of Medicine of Ribeirão Preto, University São Paulo, Ribeirão Preto, SP, Brazil. rguirro@fmrp.usp.br
Weis
Luciana Cezimbra
LC
D002138:Calibration; D004867:Equipment Design; D019544:Equipment Failure Analysis; D054020:Lasers, Gas; D054023:Lasers, Semiconductor; D028022:Low-Level Light Therapy / Q000295:instrumentation*; D026741:Physical Therapy Modalities / Q000295:instrumentation*