Probing elastic anisotropy of human skin in vivo with light using non-contact acoustic micro-tapping OCE and polarization sensitive OCT

Abstract

Skin broadly protects the human body from undesired factors such as ultraviolet radiation and abrasion and helps conserve body temperature and hydration. Skin’s elasticity and its level of anisotropy are key to its aesthetics and function. Currently, however, treatment success is often speculative and subjective, and is rarely based on skin’s elastic properties because there is no fast and accurate non-contact method for imaging of skin’s elasticity. Here we report on a non-contact and non-invasive method to image and characterize skin’s elastic anisotropy. It combines acoustic micro-tapping optical coherence elastography (AμT-OCE) with a nearly incompressible transversely isotropic (NITI) model to quantify skin’s elastic moduli. In addition, skin sites were imaged with polarization sensitive optical coherence tomography (PS-OCT) to help define fiber orientation. Forearm skin areas were investigated in five volunteers. Results clearly demonstrate elastic anisotropy of skin in all subjects. AμT-OCE has distinct advantages over competitive techniques because it provides objective, quantitative characterization of skin’s elasticity without contact, which opens the door for broad translation into clinical use. Finally, we demonstrate that a combination of multiple OCT modalities (structural OCT, OCT angiography, PS-OCT and AμT-OCE) may provide rich information about skin and can be used to characterize scar.

A non-invasive computational method to determine the directionality of skin tension lines

“…The underlying fibers become more directional in nature and this causes an increase in mechanical anisotropy [29,38]. These changes in the underlying tissues are reflected in the topography of skin in the form of geometrical anisotropy [5,39]. This change in the nature of human skin with age is well known and clearly the proposed method is able to capture this phenomenon.…”

Label-free optical interferometric microscopy to characterize morphodynamics in living plants

“…Optical coherence tomography (OCT) provides cross-sectional images of the internal structure of biological tissues with axial resolution of m ( Kirby et al., 2022 ). For OCT, a light beam from a broadband light source is divided into a reference and a sample beam.…”

Correlation analysis between texture features and elasticity of skin hyperspectral images in the near‐infrared band

“…These devices require specialized knowledge to interpret the measurement results. The principle of elasticity measurement, which applies a suction method that creates temporary deformation by contact with the skin, can cause damage in the case of skin weakened by disease 10 . Therefore, it is necessary to go beyond noninvasive and noncontact skin evaluation methods when measuring skin characteristics.…”