Korean Journal of Optics and Photonics (한국광학회지)

Optical Society of Korea (한국광학회)
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FHD Flexible Endoscopy Design Using Wedge Prism

Wedge Prism을 이용한 FHD급 연성 내시경 광학계 설계

  • Park, Sung-Woo (Department of Nano-semiconductor Engineering, Tech University Korea) ;
  • Jung, Mee-Suk (Department of Nano-semiconductor Engineering, Tech University Korea)
  • 박성우 (한국공학대학교 나노반도체공학과) ;
  • 정미숙 (한국공학대학교 나노반도체공학과)
  • Received : 2022.11.04
  • Accepted : 2022.11.24
  • Published : 2022.12.25
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Abstract

In this paper, a wedge prism application method was studied to design a full-high-definition (FHD)-class high-resolution flexible endoscope. In the case of the conventional flexible endoscope optical system, the F number is made large or a liquid lens is applied to obtain the same imaging performance in a wide depth of field. However, there is a problem in that the diameter of the optical system increases because an additional light guide and equipment are required. To solve this problem, two wedge prisms were applied to the flexible endoscope optical system to adjust the image distance for each object distance. First, two wedge prisms were symmetrically placed on the designed endoscopic optical system. An image distance satisfying the target imaging performance according to each objective distance was derived. Next, the wedge prism decenter value for controlling the image distance was derived. By combining these two data, a wedge prism decenter value that satisfied the target imaging performance at each object distance was applied in multi configurations. As a result of the optimal design applied with the wedge prism, a target imaging performance of more than 20% of the modulation transfer function for a resolution of 178 cycles/mm was satisfied in the entire depth of field of 100 mm-7 mm.

FHD급 고해상도 연성 내시경을 설계하기 위한 wedge prism 적용 방법을 연구하였다. 기존의 연성 내시경 광학계의 경우, 넓은 피사계 심도 범위에서 동일한 결상 성능을 얻기 위해 F 넘버를 크게 가져가거나 액체 렌즈를 적용하였다. 하지만 이는 추가적인 light guide와 기구물을 필요로 하여 광학계의 직경이 커진다는 문제점이 있다. 이를 해결하기 위해, 연성 내시경 광학계에 2매의 wedge prism을 적용하여 각 물체거리별로 상거리를 조절하였다. 먼저 설계한 내시경 광학계에 2매의 wedge prism을 대칭으로 배치하고, 각 물체거리별로 목표 결상 성능을 만족하는 상거리 값을 도출하였다. 그 다음, 상거리를 조절하기 위한 wedge prism 디센터 값을 도출하였다. 이 두 가지 데이터를 조합하여, 각 물체거리에서 목표 결상 성능을 만족하는 wedge prism 디센터 값을 다중구성으로 적용하였다. Wedge prism을 적용한 최적 설계 결과, 100 mm-7 mm의 전체 피사계 심도 범위에서, 분해능 178 cycles/mm에 대한 변조전달함수 20% 이상의 목표 결상 성능을 만족하였다.

Keywords

Acknowledgement

본 연구는 정부(과학기술정보통신부, 산업통산자원부, 보건복지부, 식품의약품안전처)의 재원으로 범부처전주기의료기기연구개발사업단의 지원을 받아 수행된 연구임(과제고유번호: KMDF_PR_20210526_0002-2021-05).

References

  1. J.-Y. Jun, "의료용 내시경의 이해와 응용," The Magazine of the IEIE 42, 35-41 (2015).
  2. J. F. Ortega-Moran, A. Azpeitia, L. F. Sanchez-Peralta, L. Bote-Curiel, B. Pagador, V. Cabezon, C. L. Saratxaga, and F. M. Sanchez-Margallo, "Medical needs related to the endoscopic technology and colonoscopy for colorectal cancer diagnosis," BMC cancer 21, 467 (2021). https://doi.org/10.1186/s12885-021-08190-z
  3. T. Hatano, "Olympus creates new Asian markets by training doctors," (Nokkei Asia, Published date: Apr. 26, 2018), https://asia.nikkei.com/Business/Companies/Olympus-creates-newAsian-markets-by-training-doctors (Accessed date: Nov. 28, 2022).
  4. S. Kuiper, "Electrowetting-based liquid lenses for endoscopy," Proc. SPIE 7930, 793008 (2011).
  5. OmniVision Technologies Co., "OMNIVISION launches the world's most power-efficient 1080p/60 high definition image sensor," (OmniVision Technologies Co., Published date: Jun 2, 2014), https://www.ovt.com/press-releases/omnivision-launches-the-worlds-most-power-efficient-1080p-60-high-definitionimage-sensor/ (Accessed date: Nov. 28, 2022).
  6. H. Sun, Lens Design: A Practical Guide, 1st ed. (CRC Press, USA, 2016)
  7. C.-T. Yen, Z.-W. Lai, Y.-T. Lin, and H.-C. Cheng, "Optical design with narrow-band imaging for a capsule endoscope," J. Healthc. Eng. 2018, 5830759 (2018). https://doi.org/10.1155/2018/5830759