Human skin plays vital roles in both the sensory system and thermoregulation, and also provides an important line of defense for the body from the external environment. However, experimental methods that enable in vivo characterization of this multi-layered organ are currently lacking. Soft tissue artificial phantoms can be used to diagnose certain skin diseases or to validate the efficacy of medical procedures. This study proposes a non-invasive method to obtain three-dimensional displacement measurements of soft tissue using suction and digital image correlation. We developed a measurement device capable of applying suction loading while capturing images of the full-field deformation of the area of interest. Soft tissue phantoms were fabricated, and a temporary speckle pattern was applied to each surface to provide unique features required for image correlation. A soft tissue phantom with less stiff inclusions of various diameters and a 3D printed ellipsoid was prepared. Analysis was performed using an open-source software, DICe, and both peak displacement and pressure were further parameterized for comparison metrics. The stiffness of each material was validated by comparison to each other and a hard surface. The softer inclusions were not detected, however, the material with inclusions behaved differently than the control, indicating an overall change in material properties. Preliminary results support the use of the parameterizations as comparison metrics and demonstrate the successful application of 3D-DIC to measure deformation of a surface under suction loading. The device can be modified in the future to enable measurement of surfaces with larger contours or smaller regions of interest. The compact design of the instrument permits data collection in a range of environmental conditions outside of the lab, facilitating experiments that are currently not possible.

Chair: Deanna Gates