• Biomedical Science Letters
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• v.15 no.1
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• pp.81-86
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• 2009

Lasers are necessity in our life related to the fields of medicine and cosmetic surgery. With 808 nm diode laser and $CO_2$ laser, we made some wounds on a dorsum of rat by laser irradiation. All of irradiations shows thermal effects on the whole region of skin tissues. They make wound damage depending on laser power and irradiation time. Because a collagen is plays an important role in tissue repair, we studied collagen accumulation in wound tissue. For wound healing, collagen accumulation was found in the near region of damage in epidermis and dermis layer of the rat skin. In case of the quantitative analysis of collagen in wound tissue, the amount of collagen in wound tissue by $CO_2$ laser irradiation is higher than that of 808 nm diode laser irradiation. And re-epithelialization was significantly faster in wound by $CO_2$ laser irradiation compared with that of 808 nm diode laser irradiation.

• 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.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.7
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• pp.674-678
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• 2008

Low level laser therapy has various therapy effects. 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 laser diode and microprocessor unit. The apparatus used a 635 nm laser diode for laser medical therapy and was designed for a pulse width modulation type to increase stimulation effects. In this study, the designed device was used to find out how 635 nm laser diode affected the skin injury of SD-Rat(Sprague-Dawley Rat). We divided the participants into two groups; irradiation group which was irradiated 10 minutes a day for 9 consecutive days, and none irradiation group. The results showed that the study group had lower incidence of inflammation and faster recovery, compared with the control group.

• Korean Journal of Acupuncture
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• v.27 no.1
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• pp.49-62
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• 2010

Objective: This study was performed to investigate the effect of manual acupuncture, invasive laser acupuncture and laser skin irradiation at LU8, LR4, HT8 and LR2(Liver Seunggyeok) on D-galN-induced liver injury in rats. Method: Liver injury was induced with D-galN. The experimental rats were divided four groups(Control group, EXP-1, EXP-2, EXP-3). In the Control group, liver injury-induced and not treated. EXP-1 group was liver injury-induced and carried out manual acupuncture with Young-Su(against the meridian course and following the course of the meridian) & Won-Bang(by twisting and rotating the needle) acupuncture method at Liver Seunggyeok. EXP-2 group was liver injury-induced and carried out invasive laser acupuncture at Liver Seunggyeok. EXP-3 group was liver injury-induced and carried out laser skin irradiation at Liver Seunggyeok. Result: In the change of body weight(in 1 week), EXP-1, EXP-2 and EXP-3 groups were significantly increased as compared with control group. In the change AST & ALT, EXP-1 and EXP-2 groups were significantly decreased as compared with control group. In the change of SOD, EXP-1, EXP-2 and EXP-3 groups were significantly increased as compared with control group. In the change of WBC, EXP-2 group was significantly increased as compared with control group. Conclusion: Manual acupuncture, invasive laser acupuncture and laser skin irradiation at Liver Seunggyeok had hepatotherapeutic effect on the treatment of hepatocytotoxity. Invasive laser acupuncture was as effective as manual acupuncture on the treatment of hepatocytotocity.

• Archives of Plastic Surgery
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• v.32 no.2
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• pp.149-154
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• 2005

Low-power laser(LPL) delivers a small amount of energy without elevation of tissue temperature. LPL has been reported to have biostimulation effects including anti-inflammatory, analgesic, regenerative, immunocorrective, and vasodilative effects. However, the effect of LPL on hair growth has rarely been studied. We investigated the effect of LPL on hair growth in the mouse. After depilation of back skin of mice, we classified the mice into 4 groups: control, laser irradiated group, $MoandMore^{(R)}$ applied group, and Spella $707^{(R)}$ applied group. Laser irradiation or application of these drugs were performed on the back skin of the mice for 30 days. The results are summarized as follows. Hair growth of control was first observed at 13 days after depilation, and complete hair regrowth was observed at 25 days. Hair growth of both laser irradiation group and $MoandMore^{(R)}$ applied group was first observed at 9 days after depilation, and complete hair regrowth was observed at 20 days. Hair growth of Spella $707^{(R)}$ applied group was firstly observed at the 9 days after depilation, and complete hair regrowth was observed at the 15 days. Hair growth started at the irradiation site in the laser irradiation group, but it started at the random sites in other groups. In conclusion LPL irradiation have a stimulating effect on the hair growth in the mouse.

• Journal of Biomedical Engineering Research
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• v.31 no.1
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• pp.81-86
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• 2010

Laser irradiation is known to affect various tissues such as skin, bone, nerve, and skeletal muscle. Laser irradiation promotes ATP synthesis, facilitates wound healing, and stimulates cell proliferation and angiogenesis. In skeletal muscle, laser irradiation is related to the proliferation of skeletal muscle satellite cells. Normal skeletal muscle contains remodeling capacity from myogenic cells that are derived from mononuclear satellite cells. Their processes are activated by the expression of genes related with myogenesis such as muscle-specific transcription factors (MyoD and Myf5) and VEGF (vascular endothelial growth factor). In this study, we hypothesized that laser irradiation would enhance and regulate muscle cell proliferation and regeneration through modulation of the gene expressions related with the differentiation of skeletal muscle satellite cells. $C_2C_{12}$ myoblastic cells were exposed to continuous/non-continuous laser irradiation (660nm/808nm) for 10 minutes daily for either 1 day or 5 days. After laser irradiation, cell proliferation and gene expression (MyoD, Myf5, VEGF) were quantified. Continuous 660nm laser irradiation significantly increased cell proliferation and gene expression compared to control, continuous 808nm laser irradiation, and non-continuous 660nm laser irradiation groups. These results indicate that continuous 660nm laser irradiation can be applied to the treatment and regeneration of skeletal muscle tissue.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.8
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• pp.760-765
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• 2008

Low power laser therapy is internationally certified and is known to be effective in stimulating DNA in living organisms, increasing protein synthesis and activating cell division, smoothing blood circulation, promoting cell activation, cell regeneration and function. It also has anti-inflammatory, anti-edemic, anti-fibrous dysplastic and neuralogic hyperfunctional effects. This study was intended to verify the effect of LED irradiation therapy on wound healing in cell and animal tests by applying LED irradiator using a laser and laser diode, which was independently designed and developed to emit beams of similar wavelength to that of a laser. This equipment was fabricated using a micro-controller and a high brightness LED, and designed to enable us to control light irradiation time, intensity and reservation. In case of cell proliferation experiment, each experiment was performed to irradiation group and non-irradiation group for tissue 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 590 nm transmittance of micro-plate reader. In the wound healing experiment, 1$cm^2$ wounds on the skin wound of SD-Rat(Sprague-Dawley Rat) were made. Light irradiation group and none light irradiation group divided, each group was irradiated one hour a day for 9 days. As a result, the cell increase of tissue cells was verified in irradiation group as compared to non-irradiation group. And, compared with none light irradiation group, the lower incidence of inflammation and faster recovery was shown in light irradiation group.

• Biomedical Science Letters
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• v.6 no.2
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• pp.119-129
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• 2000

The skin is an organ that has many important roles, including protection against infection, regulation of temperature and fluid loss, and sensory function. Injury to the skin, wound repair normally involves: (1) balanced activity of inflammation, (2) the re-epithelial phase and (3) the matrix formation of remodeling phase. Thus, skin wound healing is a finely controlled biological process involving a series of complex cellular interactions. Laser therapy is being implemented with increasing frequency in medicine. Low intensity laser is one that is capable of producing an energy density so low that any biologic alterations are the result of direct irradiation effect, not thermal events. This study was designed to evaluate the efficacy of low intensity laser therapy on skin wound healing in rabbits. A total of 10 male rabbits (New Zealand White Rabbit), age 8 weeks were used. Skin wound were surgically created dorso-lateral on the flank of 10 rabbits (2$\times$2 cm/damage areas). The experimental animals were treated with 5Hz (830 nm wave length) low-intensity laser (MILTA-01 Model) daily for 10 min (1.6 J/$cm^2$) for 12 days. Control animals were sham treated with the laser head. Laser irradiation animals showed a complete remodeling of the epithelial layer, a positive repair of connective tissues, and enhanced the wound closure rate over time as compared to the control animals. Especially, laser irradiation groups improved fibroblast activity, cellular content, granulation tissue formation, and collagen deposition which is resulted in improving the tensile strength of the wound. These findings suggest that laser photostimulation could accelerate healing of open wound in rabbits, and may be benefit in the treatment of open wound, including decubitis ulcers.

• The Journal of Korean Physical Therapy
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• v.14 no.3
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• pp.226-237
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• 2002

This study was performed to investigate the effect of low power laser irradiation on epidermal growth factor(EGF) expression in the burned skin of the rats. Burns of about 3cm in diameter were created with 75'c water on the back of the rats, and the lesion of experimental group were irradiated on days 1, 2, and 3 postwounding. Control tensions were not irradiated. After burns, low power laser irradiation was applied by using 1000Hz, 830nm GaAlAs (Gallium-aluminum- arsenide) semiconductor diode laser. The expression of epidermal growth factor evaluated immunohistochemistry on mouse anti-EGF. The results of this study were as follows 1. In expression of EGF, the lesion of experimental group made EGF to more induce significantly than control tensions. 2. EGF immunoreactivity in burned skin were increased markedly 3 days after burns, and increased gradually from 1 day to 2 days in burns which is laser irradiation These data suggest that low power laser have wound healing effect in the burned skin of the rats.

• The Journal of Korean Physical Therapy
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• v.15 no.3
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• pp.239-250
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• 2003

This study was performed to investigate the effect of low power laser irradiation on Substance P(SP) expression in the burned skin of the rats. Burns of about 3cm in diameter were created with $75^{\cric}C$ water on the back of the rats, and the lesion of experimental group were irradiated on days 1, 2, 3 and 4 postwounding. Control leasions were not irradiated. After burns, low power laser irradiation was applied by using 1000Hz, 830nm GaAlAs(Gallium-aluminum-arsenide) semiconductor diode laser. The expression of evaluated Substance P(SP) immunohistochemistry on rabbit anti-SP The results of this study wereas follows 1. The Substance P was expressed in the lamina I and II of dorsal horn of spinal cord. In expression of SP, the lesion of control group made SP to more induce significantly than experimental leasions. 2. SP immunoreactivity in burned leasion of spinal cord were decreased markedly 4 days after burns, and decreased gradually from 1 day to 2 days in burns which is laser irradiation These data suggest that low power laser have a pain release effect in the burned skin of the rats.