Polydisperse scattering theory and comparisons with data for red blood cells

Area of Science:

• Physics
• Biophysics
• Acoustics

Background:

• Low-frequency scattering analysis is crucial for understanding particle suspensions.
• Previous models for monodisperse particles had limitations in explaining complex biological fluid dynamics.
• Correlated particle distributions and polydispersity influence scattering properties.

Purpose of the Study:

• To numerically analyze low-frequency scattering by polydisperse distributions of correlated particles.
• To investigate the impact of particle shape, correlations, and size variation on scattering.
• To refine scattering models for better interpretation of experimental data, particularly for biological suspensions.

Main Methods:

• Numerical analysis of scattering from polydisperse particle distributions.
• Parameterization of particle correlations (c) and polydispersity (d) using gamma probability density.
• Investigation of incoherent scattering (delta) as a function of particle volume fraction (w).

Main Results:

• Polydispersity (d > 0) causes scattering curves (delta(w)) to decrease more gradually with increasing volume fraction (w).
• The fluctuation-correlation function S(w) captures the effect of polydispersity on scattering.
• Models incorporating polydispersity provide improved fits to experimental ultrasonic scattering data for red blood cell suspensions.

Conclusions:

• Polydisperse scattering models offer enhanced accuracy for analyzing biological suspensions like red blood cells.
• Accounting for particle size variation is essential for broader applicability and better data fitting in scattering studies.
• This approach facilitates more precise inversion of ultrasonic scattering data across various flow conditions and hematocrit levels.