Tissue viability imaging for assessment of skin erythema and blanching

Abstract

Tissue Viability Imaging (TiVi) is an emerging polarization spectroscopy camera technology that takes subjectivity out of skin testing by making it possible to quantify what is generally observed by the naked eye. In addition to mapping skin erythema and blanching, optional toolboxes provide for in vivo objective and quantitative assessment of wrinkle appearance, pigmentation, surface smoothness, and other skin parameters of interest. TiVi was designed with ease of use in mind and productive in gaining investigator-independent data from large panels of test subjects. By reducing data from a sequence of images to curves and indexes, TiVi is a versatile tool in skin testing including evaluation of skin care products, assessment of pharmaceuticals, and in grading the performance of sensitive skin to various challenges. When investigating the skin microcirculation, TiVi measures – in contrast to laser Doppler technology – only the concentration of red blood cells (RBCs) in tissue and not their velocity, thereby making the images closer related to what is observed by the naked eye. Furthermore, TiVi is not sensitive to movement artifacts and the distance to the object, but the amount of skin pigmentation modulates the output signal. This disadvantage is eliminated when recording only changes in skin RBC concentration as response to, e.g., topical application of a vasoactive agent, since these changes generally appear on a timescale much shorter than that at which the melanin content of the skin is altered.