2018 Volume 4 Pages 17-00656
Although various apparatuses have been developed to assess the skin mechanical function, the spatial viscoelastic behavior of each skin layer including the epidermis and dermis is yet unclear. To resolve that lack of clarity, we built a handmade system combining a suction device with optical coherence tomography (OCT). OCT can visualize the vertical section of the skin with high spatial resolution and high acquisition speed. In addition, we developed an algorithm for time-dependent strain tomography, named Dynamic Optical Coherence Straingraphy (D-OCSA), which can analyze the changes in strain distributions over time in sequential OCT images. Using the system, successive OCT images of volar forearm skin were obtained after the suction release, followed by calculation of spatial distribution of creep recovery time as an index of viscoelastic behavior. As a result, we revealed that the creep recovery time in the dermis was significantly larger than that of the epidermis. This is the first report to provide evidence that there is a spatial difference in the viscoelastic behavior in the skin. Future application of our method would be beneficial to the diagnosis of skin mechanical function and the validation of cosmetic and medical applications.
