Deep Tattoo Ink Depth Profiling in Ex Vivo Porcine Skin Using Diffuse Reflectance Spectroscopy

Human body is a complex system composed of various chemicals, and thus inserting any foreign chemicals can lead to long-lasting damage. One such process is tattooing, which is widely common among all sections of human society. Nevertheless, there is a huge demand for safe tattoo removal, intending to target only the ink particles and protect the skin components. This work discusses the development of a non-invasive technique to assess tattoo ink location in the deep tissue layers. Tattoo ink was injected systematically from 1--6 mm depth, parallel to the surface of an ex vivo porcine skin. The adopted methodology of the crossover point-based diffuse reflectance (DR) technique could effectively and precisely detect the tattoo ink location in the depths. A good quantitative agreement between the detected ink location and injected ink depth on cross-section tattooed skins were observed. The DR technique thus opens avenues for new applications in the clinical field for a non-invasive understanding of deep tissue regimes.