volume | PIER Journals

Abstract

This paper presents the application of unconditionally stable fundamental finite-difference time-domain (FADI-FDTD) method in modeling the interaction of terahertz pulse with healthy skin and basal cell carcinoma (BCC). The healthy skin and BCC are modeled as Debye dispersive media and the model is incorporated into the FADI-FDTD method. Numerical experiments on delineating the BCC margin from healthy skin are demonstrated using the FADI-FDTD method based on reflected terahertz pulse. Hence, the FADI-FDTD method provides further insight on the different response shown by healthy skin and BCC under terahertz pulse radiation. Such understanding of the interaction of terahert pulse radiation with biological tissue such as human skin is an important step towards the advancement of future terahertz technology on biomedical applications.

1. Han, P. Y., G. C. Cho, and X. C. Zhang, "Time-domain transillumination of biological tissues with terahertz pulses," Opt. Lett., Vol. 25, 242-244, 2000. Google Scholar

2. Smye, S. W., J. M. Chamberlain, A. J. Fitzgerald, and E. Berry, "The interaction between terahertz radiation and biological tissue," Phys. Med. Biol., Vol. 46, 101-112, 2001. Google Scholar

3. Pickwell, E. and V. P. Wallace, "Biomedical applications of terahertz technology," J. Phys. D: Appl. Phys., Vol. 39, 301-310, 2006. Google Scholar

4. Son, J.-H., "Terahertz electromagnetic interactions with biological matter and their applications," J. Appl. Phys., Vol. 105, No. 102033, 2009. Google Scholar

5. Woodward, R. M., B. E. Cole, V. P. Wallace, D. D. Arnold, R. J. Pye, E. H. Linfield, M. Pepper, and A. G. Davies, "Terahertz pulse imaging of in vitro basal cell carcinoma samples," TOPS, Vol. 56, 329-330, 2001. Google Scholar

6. Woodward, R. M., B. E. Cole, V. P. Wallace, R. J. Pye, D. D. Arnold, E. H. Linfield, and M. Pepper, "Terahertz pulse imaging in reflection geometry of human skin cancer and skin tissue ," Phys. Med. Biol., Vol. 47, 3853-3863, 2002. Google Scholar

7. Pickwell, E., B. E. Cole, A. J. Fitzgerald, M. Pepper, and V. P.Wallace, "In vivo study of human skin using pulsed terahertz radiation ," Phys. Med. Biol., Vol. 49, 1595-1607, 2004. Google Scholar

8. Wallace, V. P., P. F. Taday, A. J. Fitzgerald, R. M. Woodward, J. Cluff, R. J. Pye, and D. D. Arnone, "Terahertz pulsed imaging and spectroscopy for biomedical and pharmaceutical applications," Faraday Discuss., Vol. 126, 255-263, 2004. Google Scholar

9. Wallace, V. P., A. J. Fitzgerald, S. Shankar, N. Flanagan, R. J. Pye, J. Cluff, and D. D. Arnone, "Terahertz pulsed imaging of basal cell carcinoma ex vivo and in vivo," British J. Dermatol., Vol. 151, 424-432, 2004. Google Scholar

10. Wallace, V. P., A. J. Fitzgerald, E. Pickwell, R. J. Pye, P. F. Taday, N. Flanagan, and H. A. Thomas, "Terahertz pulsed spectroscopy of human basal cell carcinoma," Appl. Spectroscopy, Vol. 60, 1127-1133, 2006. Google Scholar

11. Yee, K. S., "Numerical solution of initial boundary value problems involving Maxwell's equation in isotropic media,", Vol. 14, No. 4, 302-307, Apr. 1966. Google Scholar

12. Taflove, A. and S. C. Hagness, Computational Electrodynamics: The Finite-Difference Time-Domain Method, Artech House, Boston, MA, 2005.

13. Pickwell, E., B. E. Cole, A. J. Fitzgerald, V. P. Wallace, and M. Pepper, "Simulation of terahertz pulse propagation in biological systems," Appl. Phys. Lett., Vol. 84, 2190-2192, 2004. Google Scholar

14. Pickwell, E., A. J. Fitzgerald, B. E. Cole, P. F. Taday, R. J. Pye, T. Ha, M. Pepper, and V. P. Wallace, "Simulating the response of terahertz radiation to basal cell carcinoma using ex vivo spectroscopy measurements," J. Biomed. Opt., Vol. 10, No. 064021, 2005. Google Scholar

15. Tan, E. L., "Fundamental schemes for efficient unconditionally stable implicit finite-difference time-domain methods,", Vol. 56, No. 1, 170-177, Jan. 2008. Google Scholar

16. Zheng, F., Z. Chen, and J. Zhang, "Toward the development of a three-dimensional unconditionally stable finite-difference time-domain method,", Vol. 48, No. 9, 1550-1558, Sep. 2000. Google Scholar

17. Namiki, T., "3-D ADI-FDTD method: Unconditionally stable time-domain algorithm for solving full vector Maxwell's equations,", Vol. 48, No. 9, 1743-1748, Oct. 2000. Google Scholar

18. Tan, E. L., "Concise current source implementation for efficient 3-D ADI-FDTD method ,", Vol. 17, No. 11, 748-750, Nov. 2007. Google Scholar

19. Sandby-Moller, J., T. Poulsen, and H. C. Wulf, "Epidermal thickness at different body sites: Relationship to age, gender, pigmentation, blood content, skin type and smoking habits," Acta Dermatol. Venereol., Vol. 83, 410-413, 2003. Google Scholar

20. Koehler, M. J., T. Vogel, P. Elsner, K. Konig, R. Buckle, and M. Kaatz, "In vivo measurement of the human epidermal thickness in different localizations by multiphoton laser tomography ," Skin Research and Technology, Vol. 16, 259-264, 2010. Google Scholar

21. Tay, W. C., D. Y. Heh, and E. L. Tan, "GPU-accelerated fundamental ADI-FDTD with complex frequency shifted convolutional perfectly matched layer ," Progress In Electromagnetics Research M, Vol. 14, 177-192, 2010. Google Scholar

22. Hale, G. M. and M. R. Querry, "Optical constants of water in the 200nm to 200um wavelength region," Appl. Opt., Vol. 12, 555-563, 1973. Google Scholar

Dr. Ding Yu Heh

Dr. Eng Leong Tan