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

Abstract

Abstract:We report development of a low-cost smartphone confocal microscope and its first demonstration of in vivo 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. In vivo 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 in vivo and may help disease diagnosis in resource-poor settings, where conducting standard histopathologic analysis is challenging. Guilabert, D. Massi, J. A. Moreno-Romero, C. Muñoz-Santos, G. Petrillo, S. Segura, H. P. Soyer, R. Zanchini, and J. Malvehy, "Dermoscopy improves accuracy of primary care physicians to triage lesions suggestive of skin cancer," J.

In vivo imaging of cervical precancer using a low-cost and easy-to-use confocal microendoscope

“…A major barrier to imaging disease-associated morphological alterations is scattering in turbid biological tissue. In reflectance microscopy, imaging contrast is generated by the refractive index gradient, which necessitates the use of optical sectioning techniques to reject scattered background [16,17,23]. In comparison, fluorescence imaging promises a higher light yield and improved imaging contrast.…”

“…As a result, structured illumination has been employed to investigate cervical lesions with improved background rejection [13,14]. Other optical sectioning techniques based on mechanical scanning or spectral encoding have also been employed to image highly scattering media in a wide range of ex vivo and in vivo clinical applications [15][16][17]. More recently, we implemented digital line-scanning apertures in the microendoscope using a digital light projector (DLP) and a CMOS sensor, which allows confocal background rejection at a low cost [18][19][20].…”

Clinical noninvasive imaging and spectroscopic tools for dermatological applications: Review of recent progress

“…Optical techniques mainly form the basis in smartphone-based imaging and sensing approaches. Numerous in vivo imaging and quantitative assessment means for smartphone-based devices have been reported, including autofluorescence imaging [146], hyperspectral imaging [147], modified spectrally encoded confocal microscopy [148], multispectral imaging [149] and NIR imaging [150]. By taking multispectral images of the skin, chromophore maps can be generated showing the snapshot spatial locations of tissue components such as melanin, HbO 2 , and Hb of in vivo skin, from which the chromophores can be quantified relatively for effortless and fast assessment of pathology severity, prognosis and therapy progress.…”

Classification of Lentigo Maligna at Patient-Level by Means of Reflectance Confocal Microscopy Data

“…Presently, this tool has greater diagnostic accuracy compared to dermoscopy, both for melanocytic and for non-melanocytic skin tumors [11][12][13]. Unlike the previous modalities, RCM remains expensive, although the number of users continues to increase [14] and recent developments have led to a degree of improvement in the portability of RCM devices [15].…”