https://scholar.dgist.ac.kr/handle/20.500.11750/189 2026-04-04T11:08:46Z https://scholar.dgist.ac.kr/handle/20.500.11750/60086 Title: 손 떨림 보정 및 광학 거리 제어를 이용한 비접촉 휴대형 공초점 망막 내시현미경 시스템 Author(s): 이명호; 조기찬; 임진택; 나종열; 송철 Abstract: We present a novel handheld confocal endomicroscopy system designed for non-contact, high-resolution retinal imaging, integrating motorized stabilization and tremor prediction. The system combines a custom PZT-driven Lissajous scanning probe, and a common-path swept-source optical coherence tomography (CPSS-OCT) sensor for depth tracking for real-time tremor compensation. This multimodal platform allows continuous imaging at the cellular level without requiring probe-to-tissue contact, addressing critical limitations of conventional probe-based confocal laser endomicroscopy(pCLE) systems. Experimental evaluations using ex-vivo bovine retina samples demonstrated significant enhancements in image clarity, with the CR score increasing by 48.43% under active tremor control. The proposed architecture offers improved image stability, precise axial focusing, and handheld portability, making it a strong candidate for clinical applications in retinal diagnostics and intraoperative imaging. 2025-06-26T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/60072 Title: 비전 기반 3차원 자세 추정을 이용한 인간 로봇 충돌 방지 시스템 Author(s): 나종열; 송철 Abstract: As human-robot collaboration becomes increasingly prevalent in medical and industrial settings, the risk of collisions is rising due to shared workspaces. Traditional approaches rely on stopping mechanisms or external sensors, which may limit system adaptability. This study proposes a camera-based method utilizing a convolutional neural network (CNN) to estimate the 3D joint coordinates of robots and humans within a unified camera coordinate frame. It estimates the 3D positions of the robot's seven joints with an average error below 5.5 mm, enabling real-time collision risk assessment through joint distance computation. This vision-based approach provides precise spatial awareness without requiring additional external sensors, enhancing safety and operational efficiency. 2025-06-25T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/59994 Title: Handheld Confocal Endomicroscope System with Tremor Compensation for Retinal Imaging Author(s): Lee, Myung Ho; Cho, Gichan; Im, Jintaek; Na, Jongyeol; Song, Cheol Abstract: Advancements in biophotonics have driven the development of miniaturized imaging probes for high-resolution in vivo imaging. Probe-based confocal laser endomicroscopy (pCLE) enables cellular-level visualization of tissues but remains challenging for retinal imaging due to the need for non-contact operation, tremor compensation, and precise focal control. This study introduces a novel handheld confocal endomi-croscope system that integrates a custom-built imaging probe, an optical coherence tomography (OCT) distance sensor, and motor-assisted tremor suppression to improve imaging stability and resolution. The system employs a fiber-based common-path swept-source OCT (CPSS-OCT) sensor to maintain a stable focal distance while compensating for involuntary hand tremors using motorized stabilization. A gated recurrent unit (GRU)-based tremor prediction algorithm further enhances image stability. The imaging probe features a PZT tube-driven fiber cantilever resonance for Lissajous scanning, providing a wide field of view with minimal image distortion. In experiments using bovine eye samples, the CR score improved from 0.318 to 0.472, with a 48.43% increase in the in-focus condition when tremor compensation was activated, confirming enhanced image clarity and stability. Experimental results demonstrate that the system effectively stabilizes imaging, reduces motion artifacts, and ensures high-resolution, non-contact retinal imaging. By addressing the limitations of conventional pCLE devices, this system represents a significant advancement in ophthalmic imaging and can potentially improve retinal diagnostics and precision-guided interventions. 2025-10-21T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/59945 Title: Compact forward-viewing multimodal fluorescent and optical coherence tomography endomicroscopic probe Author(s): Im, Jintaek; Cho, Gichan; Song, Cheol Abstract: We present a compact multimodal endomicroscope that enables simultaneous fluorescence (FL) and optical coherence tomography (OCT) imaging. While current endoscopy techniques are effective for wide-area and rapid inspection, there is a growing demand for real-time precise diagnostics, including detailed tissue morphology and tumor invasion depth. Histological analysis through biopsy remains the diagnostic standard but involves a time-consuming process that can delay treatment decisions. Our approach integrates two complementary imaging modalities-FL for visualizing tissue morphology and OCT for cross-sectional imaging-within a single probe compatible with standard gastrointestinal endoscopic channels. The system employs a Lissajous scanning mechanism to achieve forward-viewing, uniform illumination, and high-speed imaging. A compact imaging probe is fabricated by assembling a composite fiber, piezoelectric tube actuator, and asymmetrically attached polymer stiffener in parallel, enabling combined fluorescence and optical coherence imaging with complementary performance characteristics. Real-time image reconstruction is implemented using parallel computing to support high-throughput data processing. Imaging experiments on phantom targets and ex-vivo animal tissues confirm the system's capability to produce detailed, co-registered images of tissue morphology and structure. This technology offers a promising platform for enhancing diagnostic accuracy and enabling real-time decision-making in gastrointestinal endoscopy. 2025-11-30T15:00:00Z