• 전자공학회논문지SC
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• 제48권1호
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• pp.24-30
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• 2011

본 연구에서는 안구 영상을 위한 OCT용 손잡이 형 프로브를 개발하였다. 프로브는 휴대하기 간편한 손잡이 형태로 구현하였으며, 어댑터의 대물렌즈를 교체함으로써 각막(cornea)과 망막(retina) 모두 영상화 할 수 있도록 설계 하였다. 시스템의 성능검증을 위해 in vivo로 실험용 쥐의 눈 영상을 2D로 획득하였으며, 획득한 영상을 3D 영상으로 재구성하였다. 3D 영상은 쥐의 미세한 부분의 구조를 잘 나타내었으며, 움직임에 의한 흔들림 현상(Motion artifact)이 나타나지 않았으므로 개발된 OCT시스템의 이미지 디스플레이 속도는 생체 내 실험 (in vivo)에 적합함을 알 수 있었다.

• Current Optics and Photonics
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• 제7권3호
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• pp.283-296
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• 2023

An intraoral spectral domain optical coherence tomography (SD-OCT) system has been developed, using a custom-built hand-held scanner and spectrometer. The hand-held OCT probe, based on a microelectromechanical systems scanner and a self-built miniaturized drive circuit, had a field of view sufficient for dental diagnosis. The spectrometer using a fabricated f-theta lens provided the image depth required for dental diagnosis. The axial and transverse resolutions of the OCT system in air were 7.5 ㎛ and 12 ㎛ respectively. The hand-held probe could scan an area of 10 × 10 mm², and the spectrometer could image along a depth of 2.5 mm. To verify the utility of the developed OCT system, OCT images of tooth hard and soft tissues were acquired, and a user-interface program for diagnosis was developed. Early caries and microcracks that were difficult to diagnose with existing methods could be found, and the state of restoration could be observed. Measuring the depth of the gingival sulcus, distinguishing subgingival calculus, and detecting an implant under the gingiva suggested the possibility of the SD-OCT system as a diagnostic for dental soft tissues. Through the presented OCT images, the capability of the developed SD-OCT system for dental diagnosis was demonstrated.

• 대한의용생체공학회:의공학회지
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• 제32권4호
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• pp.285-288
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• 2011

In this study, we developed an optical coherence tomography(OCT) using a sweep-source laser whose center wavelength is 1310 nm and a probe of hand-held type. The developed hand-held probe targets to diagnose the middle ear, so it is miniaturized for ease and convenience of control. For the first time, we performed in-vivo clinical experiments on tympanic membrane(TM) perforation patients not reported from previous studies about OCT. The high-resolution sectional images of tympanic membrane perforation can be obtained. There aren't many studies about diagnostic instrument of the middle ear and diagnosis with sectional image of the middle ear, so the developed OCT system and hand-held probe are applicable to tympanic membrane perforation and other pathologic diagnosis in the middle ear.

• 한국통신학회논문지
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• 제39C권10호
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• pp.896-908
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• 2014

세계적인 인구 고령화와 생활수준의 향상에 따른 국민들의 건강에 대한 관심이 커지면서 최근 전자의료기기의 시장도 증대되고 있다. 수지형체외식초음파프로브는 허가 신청 건수가 높은 다빈도 허가 심사 대상 의료기기이며 최근 병원 등의 임상분야에서 그 활용도가 높다. 하지만, 수지형체외식초음파프로브의 성능 평가를 위한 국내 기준은 명확하게 마련되지 않은 실정이고, 허가심사 및 품질평가 등을 위한 가이드라인 조차 마련되어 있지 않다. 따라서 본 연구에서는 수지형체외식초음파프로브의 특성, 허가 및 시장현황을 조사하고, 관련 국내 외 규격을 검토하여 성능평가 시험항목, 기준 및 방법을 도출하였으며, 시험검증을 통하여 최종적으로 국제조화되고 국내 실정에 적합한 성능 평가 가이드라인을 마련하였다. 향후 본 연구결과를 의료기기 관련 업체에서 활용함으로써 수지형체 외식초음파프로브의 품질 및 성능 향상을 도모하고, 허가를 위한 심사 평가의 일관성을 확보할 수 있을 것으로 기대된다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2011년도 춘계학술대회 논문집
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• pp.1045-1046
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• 2011

• International journal of advanced smart convergence
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• 제7권4호
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• pp.169-173
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• 2018

Iris diagnosis based on the color and texture information is one of a novel approach which can represent the current state of a certain organ inside body or the health condition of a person. In analysis of the iris images, there are critical image artifacts which can prevent of use interpretation of the iris textures on images. Here, we developed the iris diagnosis system based on a hand-held typed imaging probe which consists of a single camera sensor module with 8M pixels, two pairs of 400~700 nm LED, and a guide beam. Two original images with different light noise pattern were successively acquired in turns, and the light noise-free image was finally reconstructed and demonstrated by the proposed artifact removal approach.

• 전기학회논문지P
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• 제59권4호
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• pp.423-427
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• 2010

Portable sheet resistance-measuring instrument using the dual-configuration Four-Point Probe method is developed for the purpose of precisely measuring the sheet resistance of conducting thin films. While single-configuration Four-Point Probe method has disadvantages of applying sample size, shape and thickness corrections for a probe spacing, the developed instrument has advantages of no such corrections, little edge effects and measuring simply and accurately the sheet resistance between $0.2\Omega/sq$ and $2k\Omega/sq$.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.929-930
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• 2007

박막재료 및 반도체의 면저항 측정에는 주로 Four Point Probe(FPP) 원리를 이용한 측정기를 사용하고 있다. FPP에 의한 측정방식은 single 및 dual configuration method가 있으며, dual configuration은 single configuration에 비해 probe spacing 변화나 시료의 가장자리 효과 등에서 측정편차가 적은 장점이 있어서 dual configuration 기술을 사용하는 추세이다. 개발된 휴대용 면저항 측정기는 dual configuration원리를 적용하여 제작되었으며, 박막재료의 면저항을 누구나 쉽고 정확하게 측정할 수 있도록 설계되었다. 또한 시료의 크기가 핀 간격에 비해 5배 이상 크면 보정계수를 거의 무시할 수 있는 장점이 있어 작은 시료라도 정확한 면저항을 측정할 수 있다. 이측정기의 측정 불확도는 지시값의 1 % 이하이고, 측정범위는 (2$\sim$2000)$\Omega/sq$이다.

• Current Optics and Photonics
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• 제5권5호
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• pp.532-537
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• 2021

We present a compact endoscopic probe in a needle form which has a fast beam-scanning capability for optical coherence tomography (OCT). In our study, a beam-scanning OCT imaging needle was fabricated with a 26G syringe needle (0.46 mm in outer diameter) and a thin OCT imaging probe based on the stepwise transitional core (STC) fiber. The imaging probe could freely rotate inside the needle for beam scans. Hence, OCT imaging could be performed without rotation or translation of the needle body. In our design, the structural integrity of the needle's steel tubing was preserved for mechanical robustness. Probing the optical signal was performed through the needle's own window formed at the end. For hand-held operation of our imaging needle, a light and compact scanner module (130 g and 45 × 53 × 60 mm³) was devised. Connected to the imaging needle, it could provide rotational actuation driven by a galvanometer. Because of its finite actuation range, our scanner module did not need a fiber rotary joint which might add undesirable complexity. The beam scan speed was 20 Hz and supported 20 frames per second at the maximum for endoscopic OCT imaging.

• Journal of electromagnetic engineering and science
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• 제15권3호
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• pp.181-184
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• 2015

Evaluation of radiating radiofrequency fields from hand-held and body-mounted wireless communication devices to human bodies are conducted by measuring the specific absorption rate (SAR). The uncertainty of system validation and probe calibration in SAR measurement depend on the variation of RF power used for the validation and calibration. RF input power for system validation or probe calibration is controlled manually during the test process of the existing systems in the laboratories. Consequently, a long time is required to reach the stable power needed for testing that will cause less uncertainty. The standard uncertainty due to this power drift is typically 2.89%, which can be obtained by applying IEC 62209 in a normal operating condition. The principle of the Automatic Input Power Level Control System (AIPLC), which controls the equipment by a program that maintains a stable input power level, is suggested in this paper. The power drift is reduced to less than ${\pm}1.16dB$ by AIPLC, which reduces the standard uncertainty of power drift to 0.67%.