Speaker
Description
Modelling photon propagation in biological tissue is crucial for developing effective in vivo optical spectroscopic methods, such as those used to quantify blood oxygenation and the concentration of cytochrome c oxidase in its various redox states. However, current analytical models of light propagation in tissue are complex, making their implementation and usage quite challenging. Recently, an approximation of the photon flux model was proposed; log(R) = log(1+ρ√(3μaμ's) ) -log(μ's)+C, where R is the measured reflectance, ρ is the source-detector separation, and C is a constant that can be removed by taking the derivative of the equation. The aim of this project was to test the validity of this simplified model against the standard equation. The differences between the models are quantified and both are fitted to in silico data to evaluate their ability to extract relevant physiological parameters such as the concentration of oxygenated and deoxygenated hemoglobin, cytochrome c oxidase, and water content. Fitting was performed over a wavelength range of 700nm to 900nm, to mimic typical spectral range used for in vivo tissue spectroscopy. While the approximation is simpler, and therefore more convenient, it fails to properly fit to the original equation. Notably, the results showed that using the simplified equation could lead to errors of up to 99% for parameters such as cytochrome c oxidase and oxyhemoglobin, 25% for water and 21% for deoxyhemoglobin concentrations. These findings suggest that this approximation is inaccurate and should not be used to estimate the aforementioned tissue parameters.
| Keyword-1 | Photon propagation model |
|---|---|
| Keyword-2 | Simulation |
| Keyword-3 | Tissue chromophores |