Development of a Fiber Optic Probe to Measure NIR Raman Spectra of Cervical Tissue In Vivo

Authors

  • Anita Mahadevan-Jansen,

    Corresponding author
    1. Biomedical Engineering Program, University of Texas, Austin, TX, USA
    2. Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, USA
    • *Department of Biomedical Engineering, Box 1631, Station B, Nashville, TN 37235, USA. Fax: 615-343-7919; e-mail: anitha@vuse.vanderbilt.edu

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    • †When this work was done, Anita Mahadevan-Jansen and Nirmala Ramanujam were with the University of Texas at Austin, Biomedical Engineering Program; Anita Mahadevan-Jansen is now with Vanderbilt University, and Nirmala Ramanujam is now with the University of Pennsylvania, Department of Biophysics and Biochemistry, Philadelphia, PA, USA.

  • Michele Follen Mitchell,

    1. Department of Gynecology, UT MD Anderson Cancer Center, Houston, TX, USA
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  • Nirmala Ramanujam,

    1. Biomedical Engineering Program, University of Texas, Austin, TX, USA
    2. Department of Biophysics and Biochemistry, University of Pennsylvania, Philadelphia, PA, USA
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    • †When this work was done, Anita Mahadevan-Jansen and Nirmala Ramanujam were with the University of Texas at Austin, Biomedical Engineering Program; Anita Mahadevan-Jansen is now with Vanderbilt University, and Nirmala Ramanujam is now with the University of Pennsylvania, Department of Biophysics and Biochemistry, Philadelphia, PA, USA.

  • Urs Utzinger,

    1. Biomedical Engineering Program, University of Texas, Austin, TX, USA
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  • Rebecca Richards-Kortum

    1. Biomedical Engineering Program, University of Texas, Austin, TX, USA
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ABSTRACT

The goal of this study was to develop a compact fiber optic probe to measure near infrared Raman spectra of human cervical tissue in vivo for the clinical diagnosis of cervical precancers. A Raman spectrometer and fiber optic probe were designed, constructed and tested. The probe was first tested using standards with known Raman spectra, and then the probe was used to acquire Raman spectra from normal and precancerous cervical tissue in vivo. Raman spectra of cervical tissue could be acquired in vivo in 90 s using incident powers comparable to the threshold limit values for laser exposure of the skin. Although some silica signal obscured tissue Raman bands below 900 cm-1, Raman features from cervical tissue could clearly be discerned with an acceptable signal-to-noise ratio above 900 cm-1. The success of the Raman probe described here indicates that near infrared Raman spectra can be measured in vivo from cervical tissues. Increasing the power of the excitation source could reduce the integration time to below 20 s.

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