Design of a Millimeter-Wave Near-Field Probe for Early-Stage Skin Cancer Detection

摘要

This work presents the design of a practical and low-cost near-field probe for early-stage skin cancer detection. The device utilizes substrate integrated waveguide (SIW) technology to ensure an easy and cheap fabrication process. Moreover, the adoption of a high dielectric constant substrate material provides a good match with the skin. This in turn allows to use the probe in direct contact with the investigated area, making it a practical and effective tool for scanning a suspected body area in an in-vivo scenario. The tip of the device, i.e., the part that is in direct contact with the skin, is capable of concentrating the electric field on a small region thanks to a tapered design, and in this way a sub-millimeter lateral resolution of 0.2 mm can be achieved. The probe is designed to operate between 35 and 45 GHz, and to achieve a penetration depth of 0.4 mm in order to detect small cancer lumps. The device operates according to a differential approach, i.e., it senses relative changes in the dielectric properties of a suspect area with respect to its healthy surroundings. In this way, the effectiveness of the probe is granted for all the individuals and body regions, and regardless of the hydration level or thickness of the skin. The design has been realized and tested through full-wave numerical simulations in CST Microwave Studio.