Acoustic radiation force optical coherence elastography for evaluating mechanical properties of soft condensed matters and its biological applications

Abstract

Evaluating mechanical properties of biological soft tissues and viscous mucus is challenging because of complicated dynamic behaviors. Soft condensed matter models have been successfully used to explain a number of dynamical behaviors. Here, we reported that optical coherence elastography (OCE) is capable of quantifying mechanical properties of soft condensed matters, micellar fluids. A 7.5 MHz focused transducer was utilized to generate acoustic radiation force exerted on the surface of soft condensed matters in order to produce Rayleigh waves. The waves were recorded by optical coherence tomography (OCT). The Kelvin‐Voigt model was adopted to evaluate shear modulus and loss modulus of soft condensed matters. The results reported that various concentrations of micellar fluids can provide reasonable ranges of elasticity from 65.71 to 428.78 Pa and viscosity from 0.035 to 0.283 Pa·s, which are close to ranges for actual biological samples, like mucus. OCE might be a promising tool to differentiate pathologic mucus samples from healthy cases as advanced applications in the future.

Viscoelasticity Imaging of Biological Tissues and Single Cells Using Shear Wave Propagation

“…Viscosity assessment in shear wave OCE is in its early phase of development. Proposed methods used shear wave frequency dispersion [343][344][345][346], storage and loss moduli using a rheological model [347], and the elastic wave attenuation [345].…”

Optical coherence tomography for evaluating capillary waves in blood and plasma

“…The data in each column of the wave motion image was upsampled by 5 times by spline interpolation. The autocorrelation of magnitude A-scan data was used to estimate the displacement amplitude of capillary waves on the liquid surface [51,52]. After the autocorrelation calculation, the wave amplitudes were subtracted by their mean value to make the base line of wave motions to be zero and the wave motion images with time factor and propagation distance were reconstructed.…”

“…After the autocorrelation calculation, the wave amplitudes were subtracted by their mean value to make the base line of wave motions to be zero and the wave motion images with time factor and propagation distance were reconstructed. A two-dimensional Fourier transform (2D-FT) with size 5120 × 5120 points was used to decompose multiple frequencies from two-dimensional (2D) wave motion images to obtain a wavenumber-frequency representation (k-space) for dispersion analysis [52,53].…”

Characterizing thrombus with multiple red blood cell compositions by optical coherence tomography attenuation coefficient

“…Over the last two decades, optical coherence tomography (OCT) has been developed to investigate biological tissues and fluids due to ample advantages: non‐invasive, non‐contact, high spatial resolution, real‐time measurement, no ionizing radiation, and high sensitivity to the topology of a surface [24–27]. The optical attenuation coefficient in OCT is a reliable indicator to characterize various biological tissues such as arterial wall [28, 29], atherosclerotic plaques [30–32], enamel in teeth [33, 34], lymph nodes [35, 36], urothelial carcinoma in bladder [37], retinal nerve fiber layer [38, 39], human colon tissue [40], cerebral cortex [41], skin lesions [42], prostate tissue [43], breast tissue [44], and retinal microvascular [45].…”