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Fabrication of a PMN-PZT needle hydrophone for photoacoustic imaging

광음향 영상화를 위한 PMN-PZT 바늘형 수중청음기 제작

  • Received : 2016.02.05
  • Accepted : 2016.04.16
  • Published : 2016.05.31

Abstract

For application to several MHz photoacoustic imaging systems, a needle hydrophone was designed and fabricated by using PMN-PZT piezoelectric single crystal, and its characteristics were evaluated through comparison with a commercial PVDF(Polybinylidene Fluoride) hydrophone of which receiving sensitivity is known. The simulation using the KLM model results show that the peak receiving impulse response for $50{\Omega}$ terminating impedance of the fabricated hydrophone is -261.6 dB re $1V/{\mu}Pa$ and the frequency response is relatively flat over 2 ~ 12 MHz with fluctuation less than 5 dB. The measurement results using tone burst signals also show that it has higher (ave. 10.9 dB) sensitivity than the commercial hydrophone in 2 ~ 8 MHz, and the receiving sensitivity of $-255.8{\pm}2.8$ dB re $1V/{\mu}Pa$ was measured for the fabricated hydrophone. In addition, it is known that the photoacoustic signals and the image of a hair obtained by a mechanical scanned photoacoustic imaging system with the fabricated hydrophone were bigger and better than those obtained with the commercial hydrophone.

수 MHz의 초음파를 이용하는 저주파 광음향 영상장치에 적용하는 것을 목적으로 압전단결정 PMN-PZT를 사용한 바늘형 수중청음기를 설계 제작하고, 그 특성을 수신감도가 알려져 있는 상용 PVDF(Polyvinylidene Fluoride) 수중청음기와 비교하여 평가하였다. 설계한 수중청음기의 임펄스응답을 KLM 모델에 의해 시뮬레이션한 결과, $50{\Omega}$의 종단 임피던스에 걸리는 최대 전압을 기준으로 한 수신감도는 -261.6 dB re $1V/{\mu}Pa$이며, 2 ~ 12 MHz 대역에서 5 dB 이내의 비교적 평탄한 특성을 가지는 것으로 예측되었다. 제작한 수중청음기의 수신감도를 순음 펄스를 사용하여 측정한 결과, 측정 가능한 2 ~ 8 MHz 대역에서 상용의 수중청음기에 비해 평균 10.9 dB 높게 나타났으며, 그 값은 $-255.8{\pm}2.8$ dB re $1V/{\mu}Pa$이었다. 나아가, 제작한 수중청음기를 기계주사형 광음향 영상장치에 적용하여 머리카락에 대한 영상을 획득하였는바, 수신된 광음향 신호가 상용의 것보다 크고, 영상 또한 우수함을 알았다.

Keywords

References

  1. A. G. Bell, "On the production and reproduction of speech by light," Am. J. Sci. 3 rd Series 20, 305-324 (1880).
  2. C. B. Scruby, R. J. Dewhurst, D. A. Hutchins, and S. B. Palmer, "Quantitative studies of thermally generated elastic waves in laser-irradiated metals," J. Appl. Phys. 51, 6210-6216 (1980). https://doi.org/10.1063/1.327601
  3. D. O. Thompson and D. E. Chimenti, Review of progress in quantitative nondestructive evaluation (Plenum Press, New York and London, 1988), pp.1211-1218.
  4. S. J. Davies, C. Edwards, G. S. Taylor, and S. B. Palmer, "Laser-generated ultrasound: its properties, mechanisms and multifarious applications," J. Phys. D: Appl. Phys. 26, 329-348 (1993). https://doi.org/10.1088/0022-3727/26/3/001
  5. H. W. Baac, J. G. Ok, A. Maxwell, K. T. Lee, Y. C. Chen, A. J. Hart, Z. Xu, E. Yoon, and L. J. Guo, "Carbon-nanotube optoacoustic lens for focused ultrasound generation and high-precision targeted therapy," Sci. Rep. 2:989, PMC3524551, 1-8 (2012). https://doi.org/10.1038/srep00989
  6. T. Bowen, "Radiation-induced thermoacoustic soft tissue imaging," IEEE Ultrasonics Symposium, 2, 817-822 (1981).
  7. X. Wang, Y. Pang, and G. Ku, "Three-dimensional laser-induced photoacoustic tomography of mouse brain with the skin and skull intact," Optics Lett. 28, 1739-1741 (2003). https://doi.org/10.1364/OL.28.001739
  8. M. Xu and L. V. Wang, "Photoacoustic imaging in biomedicine," Review of Scientific Instruments, 77, 041101, 1-22 (2006). https://doi.org/10.1063/1.2195024
  9. L. Xi, X. Li, and H. Jiang, "Variable-thickness multilayered polyvinylidene fluoride transducer with improved sensitivity and bandwidth for photoacoustic imaging," Appl. Phys. Lett. 101, 173702, 1-2 (2012). https://doi.org/10.1063/1.4764051
  10. G. Gu and L. V. Wang, "Deeply penetrating photoacoustic tomography in biological tissues enhanced with an optical contrast agent," Optics Lett. 12, 507-509 (2005).
  11. J. Gamelin, A. Aguirre, A. Maurudis, F. Huang, D. Castillo, L. V. Wang, and Q. Zhu, "Curved array photoacoustic tomographic system for small animal imaging," J. Biomed. Opt. 13, 024007, 1-10 (2008). https://doi.org/10.1117/1.2907157
  12. X Wang, J. B. Fowlkes, J. M. Cannata, C. Hu, and P. L. Carson, "Photoacoustic imaging with a commercial ultrasound system and a custom probe," Ultrasound Med. Biol. 37, 484-492 (2011). https://doi.org/10.1016/j.ultrasmedbio.2010.12.005
  13. C. Li and L. V. Wang, "Photoacoustic tomography of the mouse cerebral cortex with a high-numerical-aperture-based virtual point detector," J. Biomed. Opt. 12, 024047, 1-3 (2009).
  14. S. A. Ermilov, T. Khamapirad, A. Conjusteau, M. H. Leonard, R. Lacewell, K. Mehta, T. Miller, and A. A. Oraevsky, "Laser optoacoustic imaging system for detection of breast cancer," J. Biomed. Opt. 14, 024007 (2009). https://doi.org/10.1117/1.3086616
  15. C. S. DeSilets, J. D. Fraser, and G. S. Kino, "The design of efficient brodeband piezoelectric transducers," IEEE Trans. Sonics Ultrason. 25, 115-125 (1978). https://doi.org/10.1109/T-SU.1978.31001
  16. R. Krimholtz, D. A. Leedom, and G. L. Matthei, "New equivalent circuit for elementary piezoelectric transducers," Electronics Lett. 38, 338-339 (1970).

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