A liquid optical phantom with tissue-like heterogeneities for confocal microscopy

Phantoms play an important role in the development, standardization, and calibration of biomedical imaging devices in laboratory and clinical settings, serving as standards to assess the performance of such devices. Here we present the design of a liquid optical phantom to facilitate the assessment of optical-sectioning microscopes that are being developed to enable point-of-care pathology. This phantom, composed of silica microbeads in an Intralipid base, is specifically designed to characterize a reflectance-based dual-axis confocal (DAC) microscope for skin imaging. The phantom mimics the scattering properties of normal human epithelial tissue in terms of an effective scattering coefficient and a depth-dependent degradation in spatial resolution due to beam steering caused by tissue micro-architectural heterogeneities.