• Journal of Korean Physical Therapy Science
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• v.8 no.2
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• pp.1033-1038
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• 2001

This studies were to investigate the effects of low power Helium-Neon Infra-Red(He-Ne IR) laser on the changes of the chemical components in serum of the peripheral neuropathy in diabetic rats. The twenty one Spraque-Dawley adult male rats were assigned to the 3 groups: the control group(N=7), the diabetic group(n=7) and the laser group(n=7). The diabetic group was induced with a single intravenous injecion of 50mg/kg body weight streptozotocin dissolved to 0.01mol/L citrate buffer, pH 4.5. The experimental1asser group was irradiated low power He-Ne IR laser for 5 minutes every day during 21 days to the diabetic group. The results were as follows: 1. ALT was increased the laser treatment group than the diabetic group. but that was not significant. 2. AST was significantly increased the laser treatment group than the control group and the diabetic group. 3. LDH was significantly decreased the diabetic group and laser treatment group. 4. ALP was significantly increased the diabetic group and laser treatment group. 5. CHOL was significantly decreased the laser treatment group than the diabetic group. 6. TRIG was significantly increased the laser treatment group than the diabetic group. 7. CPK was significantly increased the laser treatment group than the control group and the diabetic group.

• The Journal of Korean Physical Therapy
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• v.12 no.3
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• pp.287-292
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• 2000

This studies were to investigate the effects of low power wavelengths Helium-Neon Infra-Red(He-Ne 1R) laser on the changes of the serum immunoblobulin(Ig) concentrations in bum rats, The thirty Spraque-Dawley adult male rats were assigned to the 5 groups: the experimental groups(3). the bum control group(1) and the control group(1). There was made three degree burn by the 290 mW IR on the back oreach rats, from 3 days after being burned. the experimental laser groups were irradiated low power wavelengths(292Hz- 1168Hz, 4672Hz) He-Ne IR laser far 5 minutes every day during the 7days. The results were as follows; 1. The concentrations of immunoglobulin G(Ig G) in serum of all experimental groups on the treated with the low power wavelengths of the He-Ne IR laser during the 5 minutes far 7 days were significantly lower than those of bum groups, but those 1168 Hz group were significantly higher than those of the 292 Hz and 4672 Hz groups. 2. There were significantly decreased the change of the level of immunoglobulin M(Ig M) in serum of all experimental groups on the treated with 5 minutes laser fer 7 days to the burn control group. and were significantly increased on treated with more higher wavelengths groups to those of lower groups. 3. The concentrations immunoglobulin E(Ig E) in serum of the 292Hz wavelengths groups were significantly lower than those in bum control group. As above results. the changes of the immunoglobulin in serum levels on the healing process have meaningful effected with the low power wavelengths role on the treated with He-Ne IR laser.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.1
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• pp.37-42
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• 2012

LIFT (laser-induced forward transfer) is an advanced laser processing method used for selectively transferring micron-sized objects. In our study, this process was applied in order to deposit solder balls in microsystem packaging processes for electronics. Locally melted solder paste could be transferred to a rigid substrate using laser pulses. A thin glass plate with a solder cream layer was used as a donor film, and an IR laser pulse (wavelength = 1070 nm) was used to transfer a micron-sized solder ball to the receptor. Mass balance and energy balance were applied to analyze the shape and temperature profiles of the solder paste drops. The transferred solder bumps had measured diameters of 30-40 ${\mu}m$ and thicknesses of 50 ${\mu}m$ in our experiment. The limits and applications of this method are also presented.

• Journal of the Optical Society of Korea
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• v.16 no.4
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• pp.331-335
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• 2012

A miniaturized laser beam transmitter, in which a visible laser module at ${\lambda}$=650 nm is precisely stacked upon an infrared (IR) module at ${\lambda}$=905 nm, has been proposed and constructed to provide an IR collimated beam in conjunction with a collinear monitoring visible beam. In particular, the IR beam is selectively dispersed through a perforated sheet diffuser, so as to create a rapidly diverging close-range beam in addition to a highly defined long-range beam simultaneously. The complementary close-range beam plays a role in mitigating the blind region in the vicinity of the transmitter, which is inevitably missed by the main long-range beam, thereby uniformly extending the transmitter's effective trajectory that is sensed by a receiver. The proposed transmitter was designed through numerical simulations and then fabricated by incorporating a diffuser sheet, perforated with an aperture of 2 mm. For the manufactured transmitter, the IR long-range beam was observed to have divergences of ~2.3 and 1.6 mrad in the fast and slow axes, respectively, while the short-range beam yielded a divergence of ~24 mrad. The angular alignment between the long-range IR and visible beams was as accurate as ~0.5 mrad. According to an outdoor feasibility test involving a receiver, the combination of the IR long- and short-range beams was proven to achieve a nearly uniform trajectory over a distance ranging up to ~600 m, with an average detectable cross-section of ${\sim}60{\times}80cm^2$.

• Journal of the Korean Society for Precision Engineering
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• v.24 no.11
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• pp.76-83
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• 2007

The dark-field laser scattering system has been developed to inspect surface defects in infrared cut-off filters and then laser scattering characteristics against the defects are investigated. The qualitative analysis for the reliable and accurate detection performance is described through the correlation between incident angles of a laser and viewing ones of a camera. In this paper, reliable and important information with laser scattering is given for the surface defect inspection of IR filters. Its performance has been verified through various experiments.

• Journal of Welding and Joining
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• v.23 no.5
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• pp.55-60
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• 2005

A precise bonding technique, transmission laser bonding using energy transfer, for polymer micro devices is presented. The irradiated IR laser beam passes through the transparent part and absorbed on the opaque part. The absorbed energy is converted into heat and bonding takes place. In order to optimize the bonding quality, the temperature profile on the interface must be obtained. Using optical measurements of the both plates, the absorbed energy can be calculated. At the wavelength of 1100nm $87.5\%$ of incident laser energy was used for bonding process from the calculation. A heat transfer model was applied for obtaining the transient temperature profile. It was found that with the power of 29.5 mW, the interface begins to melt and bond each other in 3 sec and it is in a good agreement with experiment results. The transmission IR laser bonding has a potential in the local precise bonding in MEMS or Lab-on-a-chip applications.

• The Korean Journal of Pain
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• v.5 no.1
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• pp.44-51
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• 1992

This study examined the microscopic changes following irradiation of infrared low dose laser on injured sciatic nerves of rats. In these days, many clinicians use the low dose laser therapy in pain clinicians use the low dose laser therapy in pain clinic on various fields and dieases. But the basic mechanism and indications were not known completely. Low-dose IR(infrared) laser irradiation applied to a crushed injured sciatic nerve of rats in the right leg in bilaterally inflicted crush injury. The results were as follows 1) There are a little histological differences between laser treated group and nontreated group. 2) Low power IR-laser irradiation, when applied to the injured sciatic nerve, increased vascularization and relatively well conserved tissue organization. 3) There are little histological difference in distal muscle biopsy, but atrophic muscle fibers were seen partially. 4) We found out that more hypertrophic epineurium was present in laser-treated group.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.10 no.6
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• pp.795-802
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• 1998

For measuring the thermal diffusivity by laser flash method, raw data have to be calibrated using temperature data. We have developed in-process calibration method and polynomial calibration in which thermal diffusivity can be calibrated during measuring, This method is different from existing temperature pre-process calibration method and exponential calibration having various source of error. Using this new calibration method, measurement accuracy was improved about 1∼2% compare to the value by the existing method. We also studied more accurate fitting curve as in Figure 4 was shown the result of measuring output characteristics of IR radiometer with temperature. As illustrated in data, in-process calibration method and polynomial calibration equation is proper than pre-process calibration method and exponential calibration.

• Current Optics and Photonics
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• v.3 no.1
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• pp.1-7
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• 2019

Optical stimulation provides a promising alternative to electrical stimulation to selectively modulate tissue. However, developing noninvasive techniques to directly stimulate excitable tissue without introducing genetic modifications and minimizing cellular stress remains an ongoing challenge. Infrared (IR) light has been used to achieve optical pacing for electrophysiological studies in embryonic quail and mammalian hearts. Here, we demonstrate optical stimulation and pacing of the embryonic chicken heart using a pulsed infrared thulium laser with a wavelength of 1927 nm. By recording stereomicroscope outputs and quantifying heart rates and movements through video processing, we found that heart rate increases instantly following irradiation with a large spot size and high radiant exposure. Targeting the atrium using a smaller spot size and lower radiant exposure achieved pacing, as the heart rate synchronized with the laser to 2 Hz. This study demonstrates the viability of using the 1927 nm thulium laser for cardiac stimulation and optical pacing, expanding the optical parameters and IR lasers that can be used to modulate cardiac dynamics.

• Proceedings of the Optical Society of Korea Conference
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• 2005.02a
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• pp.144-145
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• 2005