William J. Fox

Confocal reflectance theta line scanning microscope for imaging human skin in vivo.

A confocal reflectance theta line scanning microscope demonstrates imaging of nuclear and cellular detail in human epidermis in vivo. Experimentally measured line-spread functions determine the instrumental optical section thickness to be 1.7±-0.1 μm and the lateral resolution to be 1.0±-0.1 μm. Within human dermis (through full-thickness epidermis), the measured section thickness is 9.2±-1.7 μm and the lateral resolution is 1.7±-0.1 μm. An illumination line is scanned directly in the pupil of the objective lens, and the backscattered descanned light is detected with a linear array, such that the theta line scanner consists of only seven optical components.

Confocal Reflectance Theta Line-Scanning Microscope for Imaging Human Skin

A confocal reflectance theta line scanning microscope demonstrates imaging of nuclear and cellular detail in human epidermis in vivo. Experimentally measured line-spread functions determine the instrumental optical section thickness to be 1.7 +/- 0.1 microm and the lateral resolution to be 1.0 +/- 0.1 microm. Within human dermis (through full-thickness epidermis), the measured section thickness is 9.2 +/- 1.7 microm and the lateral resolution is 1.7 +/- 0.1 microm. An illumination line is scanned directly in the pupil of the objective lens, and the backscattered descanned light is detected with a linear array, such that the theta line scanner consists of only seven optical components.

Confocal reflectance theta line-scanner for imaging tissues in vivo

A confocal reflectance theta line-scanner is being developed for imaging human tissues in vivo. The theta line scanner design potentially offers a newer alternative to current point scanners that may simplify the optics, electronics and mechanics and lead to smaller, inexpensive confocal microscopes. An oscillating galvanometric mirror directly scans in the pupil of a cylindrical lens and one-half of an objective lens, to produce a focused, scanned line in the object plane within tissue. Backscattered light is collected by the other half of the objective lens and focused onto a linear CMOS detector. The illumination is with a diode laser at 830 nm and imaging with a 10X, 0.8 NA water immersion lens. The illumination and detection paths are thus oriented at an angle (theta) to each other, and are separate everywhere except in the confocal plane. This configuration eliminates back-scattered light from optical components and enhances contrast. Optical design analysis has been verified with experimental results, demonstrating lateral resolution on the order of 1 um and optical sectioning (axial resolution) better than 5 um within living human skin. A Fourier optics-based analytical model is in progress to evaluate line spread functions versus illumination and detection pupil conditions. Nuclear and cellular detail is imaged in the epidermis of human skin in vivo and ex vivo (freshly excised specimens). Such a scanner may prove useful for imaging human tissues in clinical and intra-operative settings.

Dual modality optical imaging approach for real-time assessment of skin burns

A dual modality optical imaging approach based on high-resolution reflectance confocal microscopy (RCM) and optical coherence tomography (OCT) is proposed for assessing skin burns gravity. The preliminary testing of this approach has been performed on the skin of volunteers with burn scars and on animal tissue specimens. The initial results show that these two optical technologies have complementary capabilities that can offer the clinician a set of clinically comprehensive parameters: OCT helps to visualize deeper burn injuries and possibly quantify collagen destruction by measuring skin birefringence, while RCM provides submicron details of the integrity of the epidermal layer and identifies the presence of the superficial blood flow. Therefore, the combination of these two technologies within the same instrument may provide a more comprehensive set of parameters that may help clinicians to more objectively and noninvasively assess burn injury gravity by determining tissue structural integrity and viability.

Confocal theta line-scanner for imaging skin: A comparison to the point scanner

A confocal reflectance theta line-scanner provides optical sectioning of 2-10 ?m and images nuclear, cellular and architectural detail within human skin in vivo, comparable to that of point scanners and histology. Key design challenges are mismatch between illumination and detection paths, linear detector sensitivity, pupil edge aberrations and pixel crosstalk.

Confocal reflectance theta line-scanner for imaging human skin in vivo

A confocal reflectance theta line-scanning microscope provides axial resolution of 2-8 µm and images nuclear, cellular and architectural detail within human skin in vivo.