Journal of the Korean Society for Nondestructive Testing (비파괴검사학회지)

The Korean Society for Nondestructive Testing (한국비파괴검사학회)
권호 표지

Endoscopic Bio-Imaging Using Optical Coherence Tomography

마이크로 내시경 및 첨단 광 단층촬영기법을 이용한 생체 이미징

  • Ahn, Yeh-Chan (Department of Biomedical Engineering, Pukyong National University) ;
  • Brenner, Matthew (Beckman Laser Institute, University of California at Irvine) ;
  • Chen, Zhongping (Beckman Laser Institute, University of California at Irvine)
  • Received : 2011.07.26
  • Accepted : 2011.10.07
  • Published : 2011.10.30
Download PDF
⟨ Previous Next ⟩

Abstract

Optical coherence tomography(OCT) is an emerging medical diagnostic tool that draws great attention in medical and biological fields. It has a 10-100 times higher spatial resolution than that of the clinical ultrasound but lower imaging depth such as 1-2 mm. In order to image internal organs, OCT needs an endoscopic probe. In this paper, the principle of Fourier-domain optical coherence tomography with high-speed imaging capability was introduced. An OCT endoscope based on MEMS technology was developed. It was attached to the Fourier-domain OCT system to acquire three-dimensional tomographic images of gastrointestinal tract of New Zealand white rabbit. The endoscope had a two-axis scanning mirror that was driven by electrostatic force. The mirror stirred an incident light to sweep two-dimensional plane by scanning. The outer diameter of the endoscope was 6 mm and the mirror diameter was 1.2 mm. A three-dimensional image rendered by 200 two-dimensional tomographs with $200{\times}500$ pixels was displayed within 3.5 seconds. The spatial resolution of the OCT system was 8 ${\mu}m$ in air.

광 단층촬영기법은 의료영상진단 기기로 최근에 주목받고 있는 분야이다. 현재 병원 초음파보다 공간 해상도가 10-100배 우수하지만 침투깊이가 조직 내에서 1-2 mm로 얇기 때문에 인체 내 장기 이미징을 위하여서 반드시 내시경 기법을 동반하여야 한다. 본 연구를 통하여 고속 광 단층촬영기법을 소개하고 초소형 기전공학 기술을 바탕으로 개발된 내시경을 사용하여 New Zealand white rabbit의 식도와 위장 벽을 3차원으로 이미징한 결과를 고찰하였다. 개발된 내시경에는, 2축 스캔 반사경이 정전기력에 의하여 구동하는 구 동부 위에 위치하여, 입력광을 2축으로 스캔할 수 있도록 하는 구조를 포함하고 있다. 내시경의 외경은 6 mm이며 스캔 반사경의 직경은 1.2 mm 였다. 3.5초 동안 스캔하면서 3차원 이미지를 획득하였다. 3차원 이미지는 200개의 2차원 이미지를 쌓아서 구현되었으며 각각의 2차원 단면이미지는 $200{\times}500$ 픽셀들로 구성되었다. 이미지의 공간해상도는 공기 중에서 8 ${\mu}m$ 였다.

Keywords

References

  1. D. Huang, E. A. Swanson, C. P. Lin, J. S. Schuman, W. G. Stinson, W. Chang, M. R. Hee, T. Flotte, K. Gregory and C. A. Puliafito, "Optical coherence tomography," Science, Vol. 254, pp. 1178 (1991) https://doi.org/10.1126/science.1957169
  2. Z. Yaqoob, J. Wu, E. J. McDowell, X. Heng, and C. Yang, "Methods and application areas of endoscopic optical coherence tomography," J Biomed Opt., Vol. 11, No. 6, pp. 063001 (2006) https://doi.org/10.1117/1.2400214
  3. W. Jung, D. T. McCormick, Y.-C. Ahn, A. Sepehr, M. Brenner, B. Wong, N. C. Tien and Z. Chen, "In vivo three-dimensional spectral domain endoscopic optical coherence tomography using a microelectromechanical system mirror," Opt. Lett., Vol. 32, No. 22, pp. 3239-3241 (2007) https://doi.org/10.1364/OL.32.003239
  4. S. Kwon, G. L. Liu, K.-H. Jeong and L. P. Lee, "Micro confocal line scanning system for high density microfluidics," Proc. IEEE/LEOS Optical MEMS, Hawaii, USA, pp. 10-11 (2003)
  5. Y. C. Pei, W. Wilson, J. C. Liao and M. C. Wu, "Cell addressing and trapping using novel optoelectronic tweezers," Proceedings MEMS, Maastricht, The Netherlands, pp. 21-24 (2004).
  6. W. Piyawattanametha, R. P. J. Barretto, T. H. Ko, B. A. Flusberg, E. D. Cocker, H. Ra, D. Lee, O. Solgaard and M. J. Schnitzer, "Fast-scanning two-photon fluorescence imaging based on a microeletromechanical systems two dimensional scanning mirror," Opt. Lett., Vol. 31, pp. 2018-2020 (2006) https://doi.org/10.1364/OL.31.002018
  7. D. T. McCormick and N. C. Tien, "A mems based optical fiber scanning probe," Proc. IEEE/LEOS Optical MEMS, Lugano, Switzerland, pp. 207-208 (2002)
  8. Y. Pan, H. Xie and G. K. Fedder, "Endoscopic optical coherence tomography based on a microelectromechanical mirror," Opt. Lett., Vol. 26, pp. 1966-1968 (2001) https://doi.org/10.1364/OL.26.001966
  9. J. M. Zara, S. Yazdanfar, K. D. Rao, J. A. Izatt and S. W. Smith, "Electrostatic micromachine scanning mirror for optical coherence tomography," Opt. Lett., Vol. 28, pp. 628-630 (2003) https://doi.org/10.1364/OL.28.000628
  10. P. H. Tran, D. S. Mukai, M. Brenner and Z. Chen, "In vivo endoscopic optical coherence tomography by use of a rotational microelectromechanical system probe," Opt. Lett., Vol. 29, pp. 1236-1238 (2004) https://doi.org/10.1364/OL.29.001236
  11. Y. Wang, M. Bachman, G. P. Li, S. Guo, B. J. F. Wong and Z. Chen, "Low voltage polymer-based scanning cantilever for in vivo optical coherence tomography," Opt. Lett., Vol. 30, pp. 53-55 (2005) https://doi.org/10.1364/OL.30.000053
  12. A. Garnier, T. Bourouina, E. Orsier, T. Masuzawa, H. Fujita, T. Hiramoto and J. C. Peuzin, "A fast, robust and simple 2-D micro-optical scanner based on contactless magnetostrictive actuation," IEEE. 13th Conference on MEMS, Miyazaki, Japan, pp. 715-720 (2000)
  13. E. Thielicke and E. Obermeier, "Microactuators and their technologies," Mechatronics, Vol. 10, pp. 431-455 (2000) https://doi.org/10.1016/S0957-4158(99)00063-X
  14. H. Toshiyoshi, W. Piyawattanametha, C. T. Chan and M. C. Wu, "Linearization of electrostatically actuated surface micro-machined 2D optical scanner," J Microelectromech Syst., Vol. 10, (2001)
  15. R. A. Conant and R. S. Muller, "Cyclic fatigue testing of surface-micromachined thermal actuators," ASME Internation Mechanical Engineering Congress and Exposition, Anaheim, USA, Vol. 66, pp. 273-277 (1998)