Lookup Table-based Method for Quantifying Optical Properties of Turbid Media
Life Sciences : Therapeutics
Available for licensing
- James Tunnell, Ph.D. , Biomedical Engineering
- Narasimhan Rajaram , Biomedical Engineering
Optical techniques such as diffuse optical spectroscopy can provide a real-time, non-invasive ancillary technique for disease diagnosis. Light is delivered and collected with optical fiber probes that are placed in contact with the skin surface. The weak light pulses sample the tissue beneath the probe without damaging the skin. In addition, as tissue removal is unnecessary, such a technique is attractive as a screening tool for early cancers.
Many current strategies for extracting optical properties of biological tissue rely on complex analytical solutions, such as the diffusion approximation of the radiative transport equation. However the diffusion approximation is not valid at source-detector separations less than approximately one mean free path (-1 mm) and in highly absorbing tissue. In addition, many inverse solutions employing the diffusion approximation are computationally intensive.
Researchers at The University of Texas at Austin have developed a lookup table based method to extract optical properties of biological tissue. This approach is based solely on experimental measurements on calibration standards of known optical properties.
Unlike other current technology, it does not rely on complex analytical equations or computationally intensive algorithms for extracting optical properties. Instead, the method measures the spectrally resolved reflectance from tissue phantoms and maps the dependence of reflectance on the absorption and scattering properties. Every value of reflectance, therefore, has a corresponding set of scattering and absorption properties in the lookup table memory that is easier to retrieve than running intensive computations.
- Does not rely on complex equations or algorithms
- More efficient
- Provides easy data retrieval
- Valid at close source-detector separations
- Valid in highly absorbing tissue
- Adaptable to a wide array of source-detection geometries
- Computationally simple and fast
This technology can be used in applications interested in assessing tissue morphology. Potential applications could include endoscopes and spectral diagnostic systems for early detection of cancerous tumors.