Smartphone confocal microscopy for imaging cellular structures in human skin in vivo

Abstract

We report development of a low-cost smartphone confocal microscope and its first demonstration of <i>in vivo</i> human skin imaging. The smartphone confocal microscope uses a slit aperture and diffraction grating to conduct two-dimensional confocal imaging without using any beam scanning devices. Lateral and axial resolutions of the smartphone confocal microscope were measured as 2 and 5 µm, respectively. <i>In vivo</i> confocal images of human skin revealed characteristic cellular structures, including spinous and basal keratinocytes and papillary dermis. Results suggest that the smartphone confocal microscope has a potential to examine cellular details <i>in vivo</i> and may help disease diagnosis in resource-poor settings, where conducting standard histopathologic analysis is challenging.