Near-Field Microwave Resonating Sensor for Chronic Bone Assessment through Novel Electromagnetic Band Gap Structures

Recent advancements in near-field flexible microwave sensor technology have significantly enhanced their capabilities in wearables for noninvasive sensing. This paper aims to evaluate chronic wounds, specifically bone cracks, and their healing processes utilizing near-field microwave sensors for various designs and substrates, as the near-field effect is challenging in assessing chronic bone cracks. The proposed polyamide- and polydimethylsiloxane-based microwave sensor displays novelty in terms of resonating and electromagnetic band gap structures in the FR1 band. The sharp resonance and gain of the sensor make it suitable for wearable bandages in detecting and assessing the percentage of bone cracks. The analysis involves the utilization of tetrad cell electromagnetic band gap structures for crack detection with multiple resonance frequencies at 2.286, 2.35, 3.04, and 3.616 GHz, in which the crack analysis is varied between 0 and 100% noninvasively. The corresponding results are obtained and interpreted through simulations of various resonator use cases for comprehensive chronic bone analysis.