Unlike standard reflectance probes, this design achieves depth selectivity that is insensitive to variations in tissue scattering and anisotropy, enabling exclusive characterization of the superficial epithelium (20–200 µm) without interference from deeper layers. The compact geometry and high-index lens (n≈1.85) deliver superior focusing, high signal-to-noise ratio, and minimal specular artifacts compared to simpler optics. By balancing minimal fiber separations, maximal spot overlap, and a large collection angle, the device offers consistent penetration depth and enhanced sampling precision, making it ideal for skin analysis, epithelial cancer detection, and endoscopic tissue diagnostics.
Description
Investigators have developed a compact and simple two-channel fiber-optic depth-selective probe for in vivo assessment of superficial tissue. The inventors refer to this probe as the depth-selective probe. The depth-selective probe efficiently incorporates three approaches to limit the penetration depth: (1) minimizing the spot size of illumination beam, (2) reducing separation distance between illumination and collection areas, and (3) enlarging the collection angle, via a fiber-coupling high-index balllens and appropriate positioning of fibers and fiber-lens distance, while maintaining sufficient light collection efficiency without specular reflection.
Applications
Skin cancer screening device
Endoscopic epithelial probe
Cosmetic skin analysis system
Topical therapy monitoring probe
Wound healing assessment tool
Advantages
Consistent shallow penetration depth (<200 µm) regardless of tissue scattering and anisotropy
High collection efficiency yielding improved signal-to-noise ratios
Minimized specular reflection through optimized fiber-to-lens and inter-fiber spacing
Superior depth selectivity for targeted characterization of superficial epithelium
Robust performance across a wide range of optical properties (scattering coefficients 50–300 cm⁻¹, g>0.9)
Compact, easily integrated probe design for endoscopic or handheld reflectance spectroscopy systems
IP Status
https://patents.google.com/patent/US9451885B2
