Anisotropic mechanical characterization of human skin by in vivo multi-axial ring suction test.
Fiche publication
Date publication
mars 2023
Journal
Journal of the mechanical behavior of biomedical materials
Auteurs
Membres identifiés du Cancéropôle Est :
Dr JACQUET Emmanuelle
Tous les auteurs :
Elouneg A, Chambert J, Lejeune A, Lucot Q, Jacquet E, Bordas SPA
Lien Pubmed
Résumé
Human skin is a soft tissue behaving as an anisotropic material. The anisotropy emerges from the alignment of collagen fibers in the dermis, which causes the skin to exhibit greater stiffness in a certain direction, known as Langer's line. The importance of determining this anisotropy axis lies in assisting surgeons in making incisions that do not produce undesirable scars. In this paper, we introduce an open-source numerical framework, MARSAC (Multi-Axial Ring Suction for Anisotropy Characterization: https://github.com/aflahelouneg/MARSAC), adapted to a commercial device CutiScan CS 100® that applies a suction load on an annular section, causing a multi-axial stretch in the central zone, where in-plane displacements are captured by a camera. The presented framework receives inputs from a video file and converts them into displacement fields through Digital Image Correlation (DIC) technique. From the latter and based on an analytical model, the method assesses the anisotropic material parameters of human skin: Langer's line ϕ, and the elastic moduli E and E along the principal axes, providing that the Poisson's ratio is fixed. The pipeline was applied to a public data repository, https://search-data.ubfc.fr/femto/FR-18008901306731-2021-08-25_In-vivo-skin-anisotropy-dataset-for-a-young-man.html, containing 30 test series performed on a forearm of a Caucasian subject. As a result, the identified parameter averages, ϕˆ=40.9±8.2 and the anisotropy ratio Eˆ/Eˆ=3.14±1.60, were in accordance with the literature. The intra-subject analysis showed a reliable assessment of ϕ and E. As skin anisotropy varies from site to site and from subject to subject, the novelty of the method consists in (i) an optimal utilization of CutiScan CS 100® probe to measure the Langer's line accurately and rapidly on small areas with a minimum diameter of 14mm, (ii) validation of an analytical model based on deformation ellipticity.
Mots clés
Anisotropy, CutiScan® CS 100, Langer’s line, Multi-axial extension, Skin Mechanical Characterization
Référence
J Mech Behav Biomed Mater. 2023 03 15;141:105779