Design and development of portable handheld multimodal spectroscopic probe system for skin tissue analysis

The potential of optical spectroscopic techniques such as diffused reflectance and fluorescence as non-invasive, in vivo diagnostic tools is being explored and validated recently. In this paper, we present the design and development of a handheld, portable, multimodal fiber optic based probe scheme to sequentially measure diffuse reflectance and fluorescence. The proposed prototype is designed to sequentially acquire diffused reflectance in the broad wavelength range of 400 nm-1600 nm and fluorescence using custom-chosen spectrophotometers, monochromatic and broadband light sources, fibers to accommodate a wide wavelength range, custom-built probe distal end, and a real-time spectral stitching and display unit. The prototype is characterized using in-house fabricated phantom tissue samples with tunable optical properties such as scattering and absorption. The depth profile study is carried out using phantom tissue layers of known optical parameters followed by the sequential measurement of diffused reflectance and fluorescence from the tissue mimicking sample.