• Melanoma detection
• dermoscopy
• spectroscopy
• multimodal device
• G-Fresnel lens

According to the World Health Organization skin cancer, melanoma and non-melanoma, accounted for 8% of all cancer cases in 2020. Melanoma skin cancer is the least common skin cancer, only 21% of the total cases belong to this type but it shows the highest mortality rate (17% for melanoma and 5% for non-melanoma). There is a direct correlation between the thickness of the skin cancer and the mortality, early detection thus plays a crucial role in reducing patient mortality. The purpose of this thesis is to design and develop a miniaturized and low cost multimodal skin lesion inspection device for pre-screening and screening of melanoma. The instrument includes a dermoscopic module, that is the gold standard, and a spectroscopic module. The presence of the two modules makes the prototype an innovative device as it combines the ability to perform qualitative and quantitative lesion analysis in a single device. The spectroscopy module indeed improves performance by providing additional information and making the analysis independent of the physician's experience. The device includes an illumination system necessary for the operation of both modules. Taking into account device requirements and limitations, a circular ring array of 12 LEDs (6 VIS and 6 NIR) was chosen as the illuminator. The illuminator bandwidth was decided on the basis of the literature review. The major limitations to achieving an economic and low cost device were due to the spectroscopy module. So to reduce the overall cost and dimensions of the system a compact and economical spectroscope to be obtained by the use of a G-Fresnel lens. This PDMS optical element, that merges the functions of light focusing and light diffractions, was produced in house using the economical surface molding method.