Abstract

A portable, spatially resolved diffuse reflectance (SRDR) lensless imaging technique based on the charge coupled device (CCD), or complementary metal-oxide semiconductor (CMOS) sensor directly coupled with fiber optic bundle can be proposed for visualization of subsurface structures such as intrapapillary capillary loops (IPCLs). In this article, we discuss an experimental method for emulating a lensless imaging setup via raster scanning a single fiber-optic cable (where image is relayed onto the sensor surface through a fiber-optic cable equivalent to coupling a fiber optic conduit directly onto the sensor surface without any lenses) over a microfluidic phantom containing periodic hemoglobin absorption contrast. For mimicking scattering properties of turbid media, a diffusive layer formed of polydimethylsiloxane (PDMS) and titanium dioxide (TiO2) was placed atop of the microfluidic phantom. Thickness of the layers ranged from 0.2-0.7mm, and the μs` value of the layers were in the range of 0.85 mm⁻¹ – 4.25mm^-1. The results demonstrate that a fiber-optic bundle/plate coupled lensless imaging setup has a high potential to recover intensity modulations from the subsurface patterns. Decreasing of the interrogation volumes leads to enhanced spatial resolution of diffuse reflectance imaging, and hence, can potentially overcome the scattering caused blurring.

© 2015 SPIE