Non-Contact Dermatoscope with Ultra-Bright Light Source and Liquid Lens-Based Autofocus Function

Abstract

Dermatoscopes are routinely used in skin cancer screening but are rarely employed for the diagnosis of other skin conditions. Broader application is promising from a diagnostic point of view as biopsies for differential diagnosis may be avoided but it requires non-contact devices allowing a comparably large field of view that are not commercially available today. Autofocus and color reproducibility are specific challenges for the development of dermatoscopy for application beyond cancer screening. We present a prototype for such a system including solutions for autofocus and color reproducibility independent of ambient lighting. System performance includes sufficiently high feature resolution of up to 30 µm and feature size scaling fulfilling the requirements to apply the device in regular skin cancer screening.

Mueller Matrix Measurement of Electrospun Fiber Scaffolds for Tissue Engineering

“…With the system presented here, it is possible to measure the intensities required to calculate the MM out of 16 or 36 different measurements. For this, all polarization states given in Equation 2and Table 1 must be generated [42]. As the system was developed for in vivo MM measurement, it acquires the images comparably fast within 20 s (depending on the intensity of the light source).…”

“…Originally introduced in 1956 [36], the technology continues to attract interest in various research fields, especially in the field of tissue polarimetry, to investigate the orientation of structures like collagen [37][38][39]. In this context, it can also be applied to study human skin for different inflammatory skin diseases in dermatoscopy [40][41][42].…”

Mueller Matrix Analysis of Collagen and Gelatin Containing Samples Towards More Objective Skin Tissue Diagnostics

“…Indeed, flattening of the skin lesion while using the conventional dermatoscope leads to changes or even reduction of the blood circulation and finally affects the disease-related color of the corresponding skin site. To avoid direct skin contact during examination we developed a prototype for a non-contact, remote digital dermatoscope in previous work [ 1 , 2 ]. In an initial study we attempted to visualise skin inflammation of common inflammatory skin diseases such as psoriasis and lichen planus by non-contact remote digital dermoscopy [ 3 ].…”

Editorial on Special Issue “Modern Applications in Optics and Photonics: From Sensing and Analytics to Communication”

“…In terms of Optical Coherence Tomography (OCT), Yi et al [11] report a mesh-based Monte Carlo model in order to study OCT signals reflecting the structural and functional activities of brain tissue as well as to improve the quantitative accuracy of chromophores in tissue. Furthermore, Wang et al [12] evaluate the performance of different closed path determination methods in order to measure the topological charge (TC) of an optical vortex (OV) beam and Fricke et al [13] present a non-contact dermatoscope with ultra-bright light source and liquid lens-based autofocus function. Moreover, Fricke et al [13] could demonstrate, i.e., with their prototype, feature resolution of up to 30 µm and feature size scaling fulfilling the requirements to apply the device in regular skin cancer screening.…”