Spectral Panel - VirtualPhotonics/Vts.Gui.Wpf GitHub Wiki

Spectral Panel

This panel allows users to construct absorption and reduced scattering coefficient spectra in the red/near infrared region. It is important for the user to 'click' on a different text entry box after changing any of the values in the text boxes in order for the system to recognize that a value has been changed and to re-calculate accordingly.

Absorption Spectra μa(λ) Absorption spectra can be displayed by selecting a desired tissue type and clicking the “Plot μa” button which preloads a base μa spectra that is informed by values published in the literature (see below). The selection of a tissue type also configures a list of relevant absorbers where one can change the concentrations of relevant absorbers and click “Plot μa” again to see its impact on the absorption spectra. An additional feature is the Blood Concentration panel which allows the user to enter information regarding blood concentration in terms of Total Hemoglobin or Blood Volume Fraction together with Oxygen Saturation rather than specifying molar concentrations of hemoglobin [Hb] and oxy-hemoglobin [HbO2] separately. These calculations assume a hematocrit of 150g Hb/liter blood.

Reduced Scattering Spectra μs'(λ) Scattering spectra can be displayed selecting a desired tissue type and clicking the “Plot μs'” button which preloads a base μs'(λ) spectra using an inverse power law μs'(λ)=Aλ-B where A is the reduced scattering coefficient [mm-1] at λ=1000 nm, λ is the wavelength in micrometers and, -B is a parameter related to the size and refractive index mismatch of the scatterers in the tissue.

References References used to inform our choices for the 'pre-loaded' absorption and scattering spectra are shown below. When possible we chose data from references that we believe are authoritative and publicly available.

Skin: Saager, R.B., Cuccia, D.J., and Durkin, A.J., “Determination of optical properties of turbid media spanning visible and near-infrared regimes via spatially modulated quantitative spectroscopy” Journal of Biomedical Optics, 15(1):017012, 2010.

Brain (white and grey matter): Gebhart, S.C., Lin, W.C., and Mahadevan-Jansen, A., “In vitro determination of normal and neoplastic human brain tissue optical properties using inverse adding-doubling” Physics in Medicine and Biology, 51:2011-2027, 2006. Leung, T.S., Elwell, C.E., and Delpy, D.T. “Estimation of cerebral oxy- and deoxy-haemoglobin concenration changes in a layered adult head model using near-infrared spectroscopy and multivariate statistical analysis” Physics in Medicine and Biology, 50:5783-5798, 2005.

Breast (pre-, post-menopause): Shah, N., Cerussi, A.E., Jakubowski, D., Hsiang, D., Butler, J., Tromberg, B.J., “Spatial variations in optical and physiological properties of healthy breast tissue” Journal of Biomedical Optics, 9(3):534-540, 2004.

Liver: Germer, C-T., Roggan, A., Ritz, J.P., Isbert, C., Albrecht, D., Müller, G., Buhr, H.J., “Optical properties of native and coagulated human liver tissue and liver metastases in the near infrared range” Lasers in Surgery and Medicine, 23:194-203, 1998. Kitai, T., Miwa, M., Liu, H., Beauvoit, B., Chance, B., and Yamaoka, Y., “Application of near-infrared time-resolved spectroscopy to rat liver–a preliminary report for surgical application” Physics in Medicine and Biology, 44:2049-2061, 1999.

Data Sources for WPF version 5.0 and later

Hb,HbO2:

250 nm -1000 nm: https://omlc.org/spectra/hemoglobin/summary.html (Compiled by Scott Prahl using data from W. B. Gratzer, Med. Res. Council Labs, Holly Hill, London and N. Kollias, Wellman Laboratories, Harvard Medical School, Boston)
1001 nm - 1600 nm: https://doi.org/10.1364/BOE.2.000600 (Nachabe et. al, Biomedical Optics Express 2(3) (2011))

H2O:

400 nm - 720 nm: https://omlc.org/spectra/water/data/pope97.txt Ref: https://doi.org/10.1364/AO.36.008710 (R. M. Pope and E. S. Fry, Appl. Opt., 36, 8710--8723, (1997))
721 nm - 1600 nm: https://omlc.org/spectra/water/data/kou93b.txt Ref: https://doi.org/10.1364/AO.32.003531 (L. Kou, D. Labrie and P. Chylek, Appl. Opt., 32, 3531--3540, (1993))

Fat:

400 nm - 440 nm: https://doi.org/10.1097/RLI.0b013e318237527b (Nachabe et. al, Investigative Radiology 47(4) (2012))
450 nm – 1049 nm: https://omlc.org/spectra/fat/fat.txt Ref: https://doi.org/10.1364/BIO.2004.SF4 (R.L.P. van Veen et. al, OSA Annual BIOMED Topical Meeting, 20042004)
1050 nm - 1600 nm: https://doi.org/10.1117/1.3454392 (Nachabe et. al., Journal of Biomedical Optics 15(3) (2010))

Melanin:

250 nm - 1600 nm: https://omlc.org/spectra/melanin/mua.html Jacques McAuliffe plot data

Nigrosin:

600 nm - 1000 nm: Sigma-Aldrich Handbook of Chemical Dyes

Data Sources for WPF version 4.4 and earlier