• Journal of Dental Anesthesia and Pain Medicine
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• 제19권5호
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• pp.289-294
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• 2019

Background: Pain, limitations in opening, asymmetrical jaw movements, and temporomandibular joint (TMJ) sounds are the most common findings in temporomandibular joint disorders (TMDs), which causes excruciating pain, inflammation of the surrounding muscles, posterior fibers, and synovial fluid. This study aimed to evaluate and compare the effects of ultrasound heat therapy and low-level laser therapy (LLLT) in reducing TMD-related pain. Methods: This prospective study included 42 patients (age range, 25-45 years), who were divided into two groups of 21 patients each. All patients were prescribed a non-steroidal anti-inflammatory drug (NSAID) twice a day for 5 days for temporary relief of pain prior to the commencement of treatment. Patients were kept on a soft diet and asked to restrict mouth opening during the same period. Fifteen sessions of LLLT (Group A) or ultrasound therapy (Group B) were administered to the affected side. Results: Post-therapy, the mean visual analog scale score for group A and group B was 4.81 (2.01) and 6.19 (1.20), respectively; the difference was statistically significant and favoring the LLLT group. Similarly, the mean mouth opening for group A and group B was 3.99 (0.40) and 3.65 (0.41), respectively; the difference was statistically significant and favoring the LLLT group. Conclusion: Our study recommends LLLT for treating TMD-related pain with no underlying bony pathology.

• 비파괴검사학회지
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• 제25권5호
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• pp.391-399
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• 2005

레이저 유도 초음파 시스템은 놀은 공간분해능으로 스캐닝 하면서 광대역 범위에서 검사를 할 수 있는 비접촉식 검사 장치이다. 유도되는 초음파 신호의 크기는 펄스레이저의 출력에 의해서도 변화하지만, 연속발진 레이저빔이 위치하는 표면 상태에 따라서도 측정되는 초음파 세기는 크게 변화한다. 본 논문에서는 안정된 레이저 유도 초음파 시스템을 구성하기 위하여 펄스 레이저빔의 출력을 측정하여 초음파 발생 오차를 보정하였으며, 대상체 표면의 상태에 따라 크게 변화하는 측정용 레이저 간섭계의 측정 이득 변화를 매순간 측정하여 측정 오차를 보정하였다. 본 논문에서는 대상체 표면을 스캐닝 할 수 있도록 다이나믹 안정기가 부착된 레이저 유도 초음파 시스템을 개발하였다. 개발한 레이저 초음파 시스템은 스캐닝 과정에서 간섭계의 이득이 최대가 되는 순간을 적응적으로 포착하여 초음파를 발생시키고, 유도된 초음파 신호를 고속으로 샘플링 한 후에 실시간으로 신호처리를 한다. 본 논문에서는 안정적인 레이저 유도 초음파 시스템을 구성하기 위한 전체 시스템의 하드웨어 구성 방법과 제어 알고리듬에 대하여 기술한다. 또한 본 논문에서 제안한 발생오차 보정방법과 측정오차 보정 방법이 시스템의 성능 향상에 유효함을 실험을 통하여 확인하였다.

• 비파괴검사학회지
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• 제29권4호
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• pp.283-292
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• 2009

Laser-based ultrasonic sensing requires the probe with fixed fecal length, but this requirement is not essential in laser-based ultrasonic generation. Based on this fact, we designed a pulsed laser-based ultrasonic wave propagation imaging (UWPI) system with a tilting mirror system for rapid scanning of target, and an in-line band-pass filtering capable of ultrasoaic mode selection. 1D-temporal averaging, 2D-spatial averaging, and 3D-data structure building algorithms were developed far clearer results allowing fur higher damage detectability. The imaging results on a flat stainless steel plate were presented in movie and snapshot formats which showed the propagation of ultrasound visible as a concentric wavefield emerging from the location of an ultrasonic sensor. A hole in the plate with a diameter of 1 mm was indicated by the scattering wavefields. The results showed that this robust UWPI system is independent of focal length and reference data requirements.

• 비파괴검사학회지
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• 제26권3호
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• pp.181-189
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• 2006

A 2D finite-element numerical simulation has been developed to investigate the generation of ultrasonic waves in a homogeneous isotropic elastic slab under a line-focused laser irradiation. Discussing the physical processes involved in the thermoelastic phenomena, we describe a model for the pulsed laser generation of ultrasound in a metal slab. Addressing an analytic method, on the basis of an integral transform technique, for obtaining the solutions of the elastodynamic equation, we outline a finite element method for a numerical simulation of an ultrasonic wave propagation. We present the numerical results for the displacements and the stresses generated by a line-focused laser pulse on the surface of a stainless steel slab.

• Medical Lasers
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• 제8권2호
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• pp.80-83
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• 2019

Necrobiosis lipoidica (NL) is a rare, idiopathic, chronic granulomatous inflammatory disease of collagen degeneration with the risk of ulceration. Many procedures have been proposed to treat this rare disease. In this study, we applied LDM^®-MED for the management of NL, and this condition in our patient was chronic and refractory to other therapeutic options. To the best of our knowledge, no study has explored treatment of NL using ultrasound. Our results suggest that application of LDM^®-MED seems to be an effective treatment option for NL. Long-term and systematic studies are needed to determine whether such application of LDM^®-MED will be an innovative and effective treatment option for NL and various kinds of chronic wounds.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2009년도 춘계학술대회 논문집
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• pp.539-540
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• 2009

• 비파괴검사학회지
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• 제32권4호
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• pp.347-354
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• 2012

Using a single-line pulsed laser beam is well known as a useful noncontact method to generate a directional surface acoustic wave. In this method, different laser beam energy profiles produce different waveforms and frequency characteristics. In this paper, we considered two typical kinds of laser beam energy profiles, Gaussian and square-like, to find out a difference in the frequency characteristics. To achieve this, mathematical models were proposed first for Gaussian laser beam profile and square-like respectively, both of which depended on the laser beam width. To verify the theoretical models, experimental setups with a cylindrical lens and a line-slit mask were respectively designed to produce a line laser beam with Gaussian spatial energy profile and square-like. The frequency responses of the theoretical models showed good agreement with experimental results in terms of the existence of harmonic frequency components and the shift of the first peak frequencies to low.

• Smart Structures and Systems
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• 제25권3호
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• pp.301-310
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• 2020

The laser ultrasonic technique is gaining popularity for nondestructive evaluation (NDE) applications because it is a noncontact and couplant-free method and can inspect a target from a remote distance. For the conventional laser ultrasonic techniques, a pulsed laser is often used to generate broadband ultrasonic waves in a target structure. However, for crack detection using nonlinear ultrasonic modulation, it is necessary to generate narrowband ultrasonic waves. In this study, a pulsed laser is shaped into dual-line arrays using a spatial mask and used to simultaneously excite narrowband ultrasonic waves in the target structure at two distinct frequencies. Nonlinear ultrasonic modulation will occur between the two input frequencies when they encounter a fatigue crack existing in the target structure. Then, a nonlinear damage index (DI) is defined as a function of the magnitude of the modulation components and computed over the target structure by taking advantage of laser scanning. Finally, the fatigue crack is detected and localized by visualizing the nonlinear DI over the target structure. Numerical simulations and experimental tests are performed to examine the possibility of generating narrowband ultrasonic waves using the spatial mask. The performance of the proposed fatigue crack localization technique is validated by conducting an experiment with aluminum plates containing real fatigue cracks.

• Medical Lasers
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• 제10권1호
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• pp.15-21
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• 2021

As technology advances at a rapid rate, innovations in regenerative medicine will eventually include the use of energy-based therapeutics, such as low intensity-pulsed ultrasound stimulation (LIPUs), pulsed electromagnetic field stimulation (PMFs), and low-level laser/light therapy (LLLt) or photobiomodulation therapy (PBMt). Among these treatments, LLLt/PBMt attracted significant attention by the turn of the century, as evidenced by the numerous publications compared to LIPUs and PMFs, particularly for augmented bone regeneration (ABR). This is a testament of how the maturation of technology and scientific knowledge leads to latent compounded applications, even when the value of a technique is reliant on empirical data. This article reviews some of the notable investigations using LLLt/PBMt for bone regeneration published in the past decade, focusing on how this type of therapy has been utilized together with the existing regenerative medicine landscape.

• Composites Research
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• 제29권5호
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• pp.288-292
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• 2016

본 연구에서는 전영역 초음파전파영상화 시스템이라 불리는 새로운 초음파전파영상화 장치를 소개한다. 본 시스템은 비파괴적으로 구조를 2 축 선형 이동 스테이지 기반으로 검사한다. 일치된 초음파 센싱과 가진 레이저 빔이 구조를 스캔하며 동시에 펄스-에코 모드 레이저 초음파를 수집한다. 이 과정은 스캔영역만큼 큰 두께 방향의 전영역 초음파를 생성하는 것을 가능하도록 한다. 본 시스템을 사용하여 실제로 운용 중인 알루미늄 허니콤 구조 기반의 CN-235의 도색된 샌드위치 조종면를 검사 및 평가하고 구조 검사 결과로써 전영역 초음파전파 영상을 소개하였으며 기존 초음파 탐상 기법의 결과와 비교하여 성능 및 민감도를 검증하였다.