Non-contact dermatoscopic device with full polarization control and liquid lens based autofocus function

The so called dermatoscope, an epiluminescence microscope, is the state-of-the-art device for examination of suspicious skin areas in cancer screening. It is, for example, used to examine naevi and distinguish melanoma from a benign naevi. Current state dermatoscopy is mostly contact based. Such contact based dermatoscopes have several disadvantages compared with non-contact devices such as suppression of perfusion and distortion of the geometry. With a non-contact device, it is possible to additionally examine inflammatory skin diseases where the perfusion plays an important role. One challenge in the realization of non-contact devices is the variable distance to the imaged skin area which makes an autofocus function necessary. In our non-contact prototype, we present a fast liquid lens based autofocus approach. We use an infrared laser based distance sensor to control the liquid lens. To be able to obtain information from the skin surface or deeper skin layers, optical polarizers were integrated into the system as well. With the developed software it is possible to fully control the polarization state between. We will present recent results and discuss planned clinical studies.