• Journal of Veterinary Clinics
• /
• v.41 no.3
• /
• pp.157-164
• /
• 2024

The standard radiation protection method in the angiography suite involves the use of a thyroid shield, a lead apron, and lead glasses. However, exposure to substantial amounts of ionizing radiation can cause cataracts, tumors, and skin erythema. A newly developed curtain-type radiation protection device consists of a curtain drape composed of a five-layer bismuth and lead acrylic head-shielding plate, with both bearing an equivalent 0.25 mm lead thickness. In this study, a quality assurance phantom was used as the patient to create radiation scatter from the radiographic source, and an anthropomorphic mannequin phantom was used as the interventionalist to measure the radiation dose at seven different anatomical locations. Thermoluminescent dosimeters were used to measure the radiation dose. The experimental groups consisted of all-sided or one-sided curtain set-ups, the presence or absence of a conventional shielding system, and the orientation of beam irradiation. Consequently, the curtain-type radiation protection device exhibited better radiation protection range and capabilities than conventional radiation protection systems, especially in safeguarding the forehead, eyes, arms, and feet, with minimal radiation exposure. Moreover, the mean shielding ratios of the conventional shielding system and curtain-type radiation protection device were measured at 51.94% and 93.86%, respectively. Additionally, no significant decrease in the radiation protection range or capability was observed, even with changes in the beam orientation or one-sided protection. Compared with a conventional shielding system, the curtain-type radiation protection device decreased radiation exposure doses and improved comfort. Therefore, it is a potential new radiation protection device for veterinary interventional procedures.

• Proceedings of the Optical Society of Korea Conference
• /
• 2002.07a
• /
• pp.142-143
• /
• 2002

KIST에서는 Pulsed Laser를 사용하여 3차원 image를 재생할 수 있는 Electro-Holographic System을 만들어 CGH이미지를 구현하였다. CGH 이미지를 구현하기 위한 SLM (Spatial Light Modulator)으로 TeO$_2$ 결정의 Shear Mode 에서 동작하는 Bragg type의 다채널 AOSLM(Acousto-optic Spatial Light Modulator)이 사용되었다. 이 Bragg type 다채널 AOSLM에서는 광원이 특정 Bragg 각도로 입사하였을 때 다른 고위 차수는 억압되고 ＋나 -의 첫번째 차수의 회절 빔만이 형성된다. (중략)

• Journal of the Optical Society of Korea
• /
• v.18 no.6
• /
• pp.714-719
• /
• 2014

A pico-projector is a compact and mobile projector that has an infinite focus. We apply the pico-projector to a projection-type integral imaging system, which can expand the image depth to form multiple central depth planes. In a projection-type integral imaging system, the image flipping problem arises because the expanded elemental images pass through a lens array. To solve this problem, we propose the ray tracing of a pico-projector at a central depth plane and compensate the elemental image using a pixel-mapping process. Experiments to verify the proposed method are performed, and the results are presented.

• 제어로봇시스템학회:학술대회논문집
• /
• 2001.10a
• /
• pp.63.3-63
• /
• 2001

Inspection and shape measurement of three-dimensional objects are widely needed in industries for quality monitoring and control. In this paper, we propose a three dimensional volume reconstruction method, which is an iterative method and as uniform and simulated algebraic reconstruction technique (USART). In this method, two or more x-ray images projected from different views are needed, and also the geometry of the imaging system need to be a priori identified well. That is to say, the relative locations between the x-ray source, imaging plane and the object should be determined exactly by calibration. To achieve this, we propose a series of coordinate calibration methods of the x-ray imaging system using grid pattern images. Some experimental results of these calibrations is presented and discussed in detail ...

• Nuclear Medicine and Molecular Imaging
• /
• v.41 no.2
• /
• pp.132-140
• /
• 2007

Parkinson's disease is a common neurodegenerative disorder that is mainly caused by dopaminergic neuron loss in the substantia nigra. Several radiopharmaceutics have been developed to evaluate the integrity of dopaminergic neuronal system. In vivo PET and SPECT imaging of presynaptic dopamine imaing are already applied to Parkinson's disease and other parkinsonism, and can demonstrate the dopaminergic dysfunction. This review summarized the use of the presynaptic dopaminergic imaging in PD as biomarkers in evaluation of disease progression as well as in diagnosis of PD.

• Journal of the Korean Society of Visualization
• /
• v.21 no.3
• /
• pp.65-74
• /
• 2023

Compared to epifluorescence(EPI) microscopy which captures fluorescence from the entire depth of sample, total internal reflection fluorescence(TIRF) can selectively visualize only a single surface of it. TIRF uses a thin evanescent field generated by the total internal reflection of laser light on surface. However, conventional TIRF system are designed for total internal reflection to occur at the upper surface of sample, making them unsuitable for sessile droplet imaging. We designed a TIRF system suitable for a sessile droplet imaging by utilizing slide glass as a lightguide. We presented the details for constructing the TIRF system using a prism, slide glass, air slit, and optical trap. Then, we compared the TIRF with EPI by imaging the droplet with fluorescent particles during its drying process. As a result, TIRF allows us to distinctly visualize the drying pattern on the bottom surface of droplet.

• 한국HCI학회:학술대회논문집
• /
• 2008.02a
• /
• pp.717-721
• /
• 2008

This paper proposes an image system that can efficiently measure the spectral reflectance of a scene using RGB cameras and LED light sources. Multispectral imaging system is composed of LED controllers, LED clusters and RGB cameras. It captures full-spectral images at real-time. The system adopts a simple, empirical linear model to estimate the full spectral reflectance at each pixel. Since the model is linear, the reconstruction is efficient and stable. We estimated the spectral reflectance of various scenes using the system and showed the effectiveness of the proposed system.

• Current Optics and Photonics
• /
• v.1 no.4
• /
• pp.344-350
• /
• 2017

We present a new design approach and an example design for an image-space telecentric two-mirror system that has a fast f-number and a wide-field line image. The initial design of the telecentric mirror system is a conventional axially symmetric system, consisting of a flat primary mirror with fourth-order aspheric deformation and an oblate ellipsoidal secondary mirror to correct spherical aberration, coma, and field curvature. Even though in the optimized design the primary mirror is tilted, to avoid ray obstruction by the secondary mirror, the image-space telecentric two-mirror system shows quite good imaging performance, for a line imager.

• Current Optics and Photonics
• /
• v.7 no.2
• /
• pp.176-182
• /
• 2023

Optical coherence tomography (OCT) is being developed to guide various ophthalmic surgical procedures. However, the high cost of the intraoperative OCT system limits its availability mostly to the largest hospitals and healthcare systems. In this paper, we present a design and evaluation of a low-cost intraoperative common-path free-hand scanning OCT system. The lensed fiber imaging probe is designed and fabricated for intraocular use and the free-hand scanning algorithm that could operate at a low scanning speed was developed. Since the system operates at low frequencies, the cost of the overall system is significantly lower than other commercial intraoperative OCT systems. The assembled system is characterized and shows that it meets the design specifications. The handheld OCT imaging probe is tested on multilayer tape phantom and ex-vivo porcine eyes. The results show that the system could be used as an intraoperative intraocular OCT imaging device.

• Journal of Astronomy and Space Sciences
• /
• v.18 no.3
• /
• pp.231-238
• /
• 2001

A prototype CMOS (complementary metal oxide semiconductor) imaging system has been built and the possibility of applying to the application to astronomical observations has been investigated. The CCD (charge coupled device) image sensor has been the mainstay of image capture and astronomical imaging for the last 30 years, but CMOS devices have shown rapidly increasing success and have been adapted to many commercial imaging systems . Although the photometric performances and system noise of CMOS sensors are lower than that of CCD image sensors, CMOS Imaging system can be used to obtain general image capture for astronomical applications.