Measurement of tissue optical properties by the use of oblique-incidence optical fiber reflectometry.

Fiber-optic-based oblique-incidence reflectometry is a simple and accurate method for measuring the absorption and reduced scattering coefficients mu(a) and mu?(s) of semi-infinite turbid media. Obliquely incident light produces a spatial distribution of diffuse reflectance that is not centered about the point of light entry. The amount of shift in the center of diffuse reflectance is directly related to the medium's diffusion length D. We developed a fiber-optic probe to deliver light obliquely and sample the relative profile of diffuse reflectance. Measurement in absolute units is not necessary. From the profile, it was possible to measure D, perform a curve fit for the effective attenuation coefficient mu(eff), and then calculate mu(a) and mu?(s). This method was verified with Monte Carlo simulations and tested on tissue phantoms. Our measurements of D and mu(eff) had an accuracy of approximately 5%, thus giving us 10% and 5% accuracy for mu(a) and mu?(s), respectively.

[1]  William H. Press,et al.  Numerical Recipes in C, 2nd Edition , 1992 .

[2]  R A Groenhuis,et al.  Scattering and absorption of turbid materials determined from reflection measurements. 2: measuring method and calibration. , 1983, Applied optics.

[3]  L Wang,et al.  MCML--Monte Carlo modeling of light transport in multi-layered tissues. , 1995, Computer methods and programs in biomedicine.

[4]  J. Pickering,et al.  Double-integrating-sphere system for measuring the optical properties of tissue. , 1993, Applied optics.

[5]  B. Wilson,et al.  A diffusion theory model of spatially resolved, steady-state diffuse reflectance for the noninvasive determination of tissue optical properties in vivo. , 1992, Medical physics.

[6]  Shao‐Pow Lin.  Oblique-incidence fiber-optic reflectometry for measuring absorption and scattering in turbid media , 1997 .

[7]  S L Jacques,et al.  Use of a laser beam with an oblique angle of incidence to measure the reduced scattering coefficient of a turbid medium. , 1995, Applied optics.

[8]  Steven L. Jacques,et al.  Animated simulation of light transport in tissues , 1994, SPIE LASE.

[9]  L Wang,et al.  Error estimation of measuring total interaction coefficients of turbid media using collimated light transmission. , 1994, Physics in medicine and biology.

[10]  Brian C. Wilson,et al.  Charge-coupled device and neural-network-based instrument for the noninvasive determination of tissue optical properties in vivo , 1994, Photonics West - Lasers and Applications in Science and Engineering.

[11]  Steven Jacques,et al.  Video reflectometry to specify optical properties of tissue in vivo , 1993, Other Conferences.

[12]  Jennifer Harder,et al.  Oblique-incidence reflectometry: one relative profile measurement of diffuse reflectance yields two optical parameters , 1995, European Conference on Biomedical Optics.

[13]  M S Patterson,et al.  The use of a neural network to determine tissue optical properties from spatially resolved diffuse reflectance measurements. , 1992, Physics in medicine and biology.

[14]  R. Steiner,et al.  Spatially resolved absolute diffuse reflectance measurements for noninvasive determination of the optical scattering and absorption coefficients of biological tissue. , 1996, Applied optics.

[15]  Frank K. Tittel,et al.  Measurement of absorption and scattering spectra with oblique incidence reflectometry , 1996 .

[16]  H. A. Ferwerda,et al.  Scattering and absorption of turbid materials determined from reflection measurements. 1: theory. , 1983, Applied optics.