• Korean Journal of Acupuncture
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• v.22 no.2
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• pp.163-181
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• 2005

Objective: The purpose of this study is to review research papers on low level laser therapy (LLLT) and to improve the knowledge of LLLT field. Methods: For introduction, laser characteristics, including wavelength, medium, beam size, power, and unit power were explained. In order to understand LLLT, tissue optics and light-biomatter interaction were briefly mentioned. We reviewed 21 Korean papers on laser acupuncture and LLLT on the viewpoint of laser apparatus. Results and Conclusion: We found that the description of laser apparatus employed for LLLT experiments were not fully written. Laser wavelength and power which are the most crucial parameters, were omitted in several papers. No paper had information on beam size. In order to have high efficacy, laser should be used with proper laser parameters. Conditions of irradiation area or acupoints should be considered too. Some future technology on laser acupuncture were mentioned.

• Journal of the Optical Society of Korea
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• v.17 no.4
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• pp.289-295
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• 2013

Although low-level laser therapy (LLLT) has been a valuable therapeutic technology in the clinic, its efficacy may be reduced in deep tissue layers due to strong light scattering which limits the photon density. In order to enhance the photon density in deep tissue layers, this study developed an optical tissue clearing (OTC) laser probe (OTCLP) system which can utilize four different OTC methods: 1) tissue temperature control from 40 to $10^{\circ}C$; 2) laser pulse frequency from 5 to 30 Hz; 3) glycerol injection at a local region; and 4) a combination of the aforementioned three methods. The efficacy of the OTC methods was evaluated and compared by investigating laser beam profiles in ex-vivo porcine skin samples. Results demonstrated that total (peak) intensity at full width at half maximum of laser beam profile when compared to control data was increased: 1) 1.21(1.39)-fold at $10^{\circ}C$; 2) 1.22 (1.49)-fold at a laser pulse frequency of 5 Hz; 3) 1.64 (2.41)-fold with 95% glycerol injection; 4) 1.86 (3.4)-fold with the combination method. In conclusion, the OTCLP system successfully improved the laser photon density in deep tissue layers and may be utilized as a useful tool in LLLT by increasing laser photon density.

• The Journal of Korean Physical Therapy
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• v.14 no.2
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• pp.234-249
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• 2002

This study was performed, using c-fos and Substance P, to investigate the effect of GaAlAs laser on acute pain model induced by wound in lumbar region's spinal level. The test group was divided into control and experimental group. Control group is shamed group(c-fos and substance P expression after non-irradiation by a GaAlAs laser), The experimental group was divided into two subgroups: one is experimental group I (c-fos expression after irradiation by a GaAlAs laser), and the other is experimental group II (substance P expression after irradiation by a GaAlAs laser). The results of this study were as following: 1. The numbers of c-fos immunoreactive neuron in spinal cord was increased markedly 1 day after wound, and decreased gradually from 1 day to 2 days in wound with GaAlAs laser irradiation. 2. The changes of the average percentages of substance P immunoreactive neurons in spinal cord was increased markedly 1 day after wound, and decreased gradually from 1 day to 2 days in wound with GaAlAs laser irradiation. Therefore, decreasing the changes of c-fos and substance P expression after irradiation by a GaAlAs laser indicates and GaAlAs laser have effect on pain control.

• The Journal of Korean Physical Therapy
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• v.9 no.1
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• pp.157-166
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• 1997

The purpose of this study was to determine the effects of laser Irradiation on Human plasma $\beta-endorphin$ levels, by treating with low level helium-neon (He-Ne) and Infrared(lR) laser. The Laser was fixed frequency of 2400Hz by continuous scanning and irradiating time was 8 minutes each point. Blood samples were taken at before, after, after 15min's treatment and Plasma $\beta-endorphin$ was measured by radioimmunoassay. The samples for this study were 6 normal subjects(3male, 3female). The data were analyzed by paired t-test, one-way ANOVA and simple regression. The results of this study were as follows : 1. The human plasma $\beta-endorphin$ levels were noted as significant increase in after-treatment $(22.84{\pm}10.63pg/ml)$ as compared with before-treatment $(16.96{\pm}9.23pg/ml)$ and significant increase in after 15min's $(27.27{\pm}8.81pg/ml)$ as compared with after-treatment (p<0.05). 2. There were no significant changes in plasma g-endorphin levels between male and female. 3. The human plasma $\beta-endorphin$ levels were high associated in between session reliability (p<0.05).

• Medical Lasers
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• v.9 no.2
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• pp.89-94
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• 2020

Photobiomodulation (PBM) therapy has been investigated to enhance and accelerate the recovery of injured peripheral nerves. Based on the wide range of benefits of PBM therapy and its clinical relevance, this study reviewed the efficacy of PBM in injured facial nerves. The search was performed in the PubMed database to find relevant articles published over the last 10 years. Four animal studies, two randomized controlled studies, one case series, and five case reports were reviewed. Despite the various parameters, functional analysis showed that PBM therapy using near-infrared irradiation has beneficial effects on the recovery of the acute phase of the damaged facial nerve, especially when related to faster functional improvement. There were no reported adverse effects of PBM therapy.

• Medical Lasers
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• v.8 no.2
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• pp.50-58
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• 2019

Background and Objectives Low-level light therapy (LLLT) is an application of low-power light for various purposes such as promoting tissue repair, reducing inflammation, causing analgesia, etc. A previous study suggested the effect of light emitting diode (LED) light with the wavelength of 740 nm for promoting wound healing of corneal epithelial cells. This current study aimed to confirm the effect of LLLT for managing inflammation of a dry eye disease (DED) mouse model. Materials and Methods A total of 50C57BL/6 female mice were randomly grouped into 5 groups to compare the effect of LLLT:1) Control group, 2) Only LLLT group, 3) Dry eye group, 4) LLLT in dry eye group, and 5) Early treatment group. DED was induced with 4 daily injections of scopolamine hydrobromide and desiccation stress for 17 days, and LLLT at 740 nm was conducted once every 3 days. To analyze the effect of LLLT on the DED mouse model, tear volume, corneal surface irregularities, and fluorescence in stained cores were measured, and the level of inflammation was assessed with immunohistochemistry. Results The DED mouse model showed significant deterioration in the overall eye condition. After LLLT, the amount of tear volume was increased, and corneal surface irregularities were restored. Also, the number of neutrophils and the level of inflammatory cytokines significantly decreased as well. Conclusion This study showed that LLLT at 740 nm was effective in controlling the corneal conditions and the degree of inflammation in DED. Such findings may suggest therapeutic effects of LLLT at 740 nm on DED.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.397-398
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• 2008

This paper performed the basic study for fabricating the low level laser therapy apparatus, and one of the goals of this paper was to make this apparatus used handily. The apparatus has been fabricated using the 655nm laser diode and microprocessor unit. The apparatus used a 655 nm laser diode for laser medical therapy and was designed for a pulse width modulation type to increase stimulation effects. And then, each experiment was performed to irradiation group and non-irradiation group for cells. MTT assay method was chosen to verify the cell increase of two groups and the effect of irradiation on cell proliferation was examined by measuring 590nm transmittance of ELISA reader. As a result, the cell increase of cells was verified in irradiation group as compared to non-irradiation group.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.42 no.1
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• pp.2-8
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• 2016

Objectives: The purpose of this study was to investigate the effects of low-level laser therapy (LLLT) with a diode gallium-aluminum-arsenide (Ga-Al-As) low-level laser device on the healing and attachment of titanium implants in bone. Materials and Methods: Thirteen New Zealand white male rabbits weighing $3.0{\pm}0.5kg$ were used for this study. Dental titanium implants (3.75 mm in diameter and 8.5 mm in length, US II RBM plus fixture; Osstem, Seoul, Korea) were implanted into both femurs of each rabbit. The rabbits were randomly divided into a LLLT group and a control group. The LLLT was initiated immediately after surgery and then repeated daily for 7 consecutive days in the LLLT group. Six weeks and 12 weeks after implantation, we evaluated and compared the osseointegration of the LLLT group and control group, using histomorphometric analysis, removal torque testing, and resonance frequency analysis (RFA). The results were statistically significant when the level of probability was 0.05 or less based on a non-parametric Mann-Whitney U-test. Results: The implant survival rate was about 96%. Histologically and histomorphometrically, we observed that the titanium implants were more strongly attached in LLLT group than in control group. However, there was no significant difference between the LLLT group and control group in removal torque or RFA. Conclusion: Histologically, LLLT might promote cell-level osseointegration of titanium implants, but there was no statistically significant effects.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.5
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• pp.431-435
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• 2009

The apparatus has been fabricated using the laser diode and microprocessor unit. The apparatus used a InGaAlP laser diode for laser medical therapy and was designed for a pulse width modulation type to increase stimulation effects. To raise the stimulus effect of the human body, the optical irradiation frequency could be set up. The study has executed in-vivo experiment by employing our own developed laser diode irradiation system to investigate the effects of the InGaAlP laser diode irradiation on the wound healing as a preliminary study aimed at the application of InGaAlP laser diode to wound healing of human skin injury. The study cut out whole skin layers of Sprague-Dawley rat on the back part in 1 cm circle and observed developing effects after executing light irradiation for 9 days, and in result it is found that the light irradiation rat showed earlier wound healing than non-irradiation rat during the experimental period. In addition, there are some differences found regarding the healing process between laser diode irradiated rats and non-irradiated ones.

• Physical Therapy Rehabilitation Science
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• v.9 no.4
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• pp.244-251
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• 2020

Objective: Physical therapy techniques are required for patients with temporomandibular joint disorder (TMD), but the effects of treatment have not been compared. Therefore, effects of transcutaneous electrical nerve stimulation (TENS) and low level laser (LLL), which are most commonly used interventions, were compared. Design: Randomized controlled trial. Methods: Thirty-six participants with pain in the temporomandibular joint were enrolled, and 12 participants were randomly assigned to either the TENS group, LLL group, or placebo group. Each intervention was performed for a total of 6 sessions for 2 weeks. For the evaluation of the participants, the mouth opening (MO), pressure pain threshold (PPT), and stress were measured at three time periods: baseline, post-test, and follow-up at 2 weeks. Results: Significant interaction between groups according to each evaluation point was found only in PPT-masseter (p<0.05). The evaluation time point at which a significant difference appeared was at the post-test and follow-up at 2 weeks time periods. As a result of the post-test, the LLL group showed a significant improvement compared to the TENS group (p<0.05), and at 2 weeks follow-up, the TENS group showed a significant improvement compared to the placebo group (p<0.05). Conclusions: In this study, an experiment was conducted to compare the treatment effects when TENS, LLL, and placebo were given to patients with TMD. In addition, by quantitatively presenting the effect size of each treatment, this study suggests clinical use of TENS and LLL treatment for TMD.