• Journal of the Optical Society of Korea
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• v.14 no.4
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• pp.431-437
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• 2010

A stack of gradient-index (GRIN) rod lenses cannot be used for coherent anti-Stokes Raman scattering (CARS) microendoscopy for insertion to internal organs through a surgical keyhole with minimal invasiveness. That's because GRIN lens has large amount of inherent chromatic aberrations in spite of absolutely requiring a common focus for pump and Stokes beam with each frequency of ${\omega}_p$ and ${\omega}_S$. For this endoscopic purpose, we need to develop a long slender probe-type objective, namely probe-type microscope objective (PMO). In this paper, we introduce the structure, the working principle, and the design techniques of PMO which is composed of a probe-type lens module (PLM) and an adaptor lens module (ALM). PLM is first designed for a long slender type and ALM is successively designed by using several design parameters from PLM for eliminating optical discords between scanning unit and PLM. A combined module is optimized again to eliminate some coupling disparities between PLM and ALM for the best PMO. As a result, we can obtain a long slender PMO with perfectly diffraction-limited performance for pump beam of 817 nm and Stokes beam of 1064 nm.

• Korean Journal of Bronchoesophagology
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• v.15 no.2
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• pp.30-35
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• 2009

Lung cancer could be developed through a series of morphological changes from dysplasia to carcinoma in situ and then invasive cancer. However, precancerous lesions are generally a few cell layers thick and are detected only by chance. Autofluorescence bronchoscopy(AFB) is one of the newly developed diagnostic tools to detect the pre-cancerous lesions m the bronchial tissue. Several studies have shown that AFB improved the rate of detection of cancer and dysplastic lesions of the airway, especially those in intraepithelial stage. However, there were high rates of false positive with AFB, and it is also important to develop non-biopsy methods because of lack of accurate information of variable course of preneoplastic lesions regarding progression. So, many other technologies were developed, such as narrow band imaging(NBI), endobronchoscopic ultrasound, optical coherence tomography, and confocal fluorescence microendoscopy. Among the new machines, NBI is a new optical technology that can clearly visualize the microvascular structure m the mucosal layer. NBI seems to increase specificity without compromising sensitivity. In the future such techniques would make it possible to precisely study in detail the natural history of the premalignant epithelium.

• Korean Journal of Optics and Photonics
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• v.20 no.6
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• pp.311-318
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• 2009

We present an attractive real time in-vivo endoscopic microscope with a resolution of submicron, in which two kinds of optical correcting plates are inserted to eliminate higher order spherical aberration and field curvature. And, since the conventional objective lens is replaced to GRIN lenses with diameter of 1 mm, the above endoscopic microscope can be effectively utilized to invade minimally for live animals.

• The Korean Journal of Physiology and Pharmacology
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• v.23 no.4
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• pp.237-249
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• 2019

Confirming the direct link between neural circuit activity and animal behavior has been a principal aim of neuroscience. The genetically encoded calcium indicator (GECI), which binds to calcium ions and emits fluorescence visualizing intracellular calcium concentration, enables detection of in vivo neuronal firing activity. Various GECIs have been developed and can be chosen for diverse purposes. These GECI-based signals can be acquired by several tools including two-photon microscopy and microendoscopy for precise or wide imaging at cellular to synaptic levels. In addition, the images from GECI signals can be analyzed with open source codes including constrained non-negative matrix factorization for endoscopy data (CNMF_E) and miniscope 1-photon-based calcium imaging signal extraction pipeline (MIN1PIPE), and considering parameters of the imaged brain regions (e.g., diameter or shape of soma or the resolution of recorded images), the real-time activity of each cell can be acquired and linked with animal behaviors. As a result, GECI signal analysis can be a powerful tool for revealing the functions of neuronal circuits related to specific behaviors.