Wearable Radiofrequency Metasurface for Inflammatory Process Monitoring

Intelligent dressings are increasingly playing a key role in the treatment of inflammatory processes, especially in wound healing. This work reports the development of a low-cost, high-sensitive, and reusable sensor that can be integrated into dressing bandages to monitor pathological processes. The proposed radiating system consists of an actively fed RF probe loop and a planar 2 × 2 metasurface made of passive spiral resonator unit cells. The Q-factor maximization approach was used to achieve an effective unit-cells design. The identification of the inflammatory state is carried out by analyzing the amplitude and frequency shift variation of the external planar probe input impedance, caused by the self-resonant unit-cells sensing activity. We performed full-wave simulations to evaluate the radiating system performance in presence of healthy and inflamed tissue. Numerical results validated the introduced theoretical approach, confirming both the ability to identify the presence of the inflammatory state and also the spatial position of the disorder. Therefore, the proposed sensor is a promising alternative to help investigating clinical aspects, allowing better treatment decisions in wound healing and, more in general, in tissue health status monitoring.