Wearable Electromagnetic Head Imaging System Using Flexible Wideband Antenna Array Based on Polymer Technology for Brain Stroke Diagnosis

• Published in: IEEE transactions on biomedical circuits and systems Vol. 13; no. 1; pp. 124 - 134
• Main Authors: Alqadami, Abdulrahman S. M., Bialkowski, Konstanty S., Mobashsher, Ahmed Toaha, Abbosh, Amin M.
• Format: Journal Article
• Language: English
• Published: United States IEEE 01.02.2019; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Antenna arrays; Antennas; Bandwidths; Bleeding; Brain; Broadband; Computer simulation; Diagnosis; Diagnostic software; Diagnostic systems; EBG; flexible antenna; Head; Image detection; Imaging; Medical imaging; metamaterial; Metamaterials; Microstrip; Multilayers; Neuroimaging; Polydimethylsiloxane; polymer PDMS substrate; Polymers; Silicone resins; Siloxanes; Substrates; Surface waves; Transmission lines; Unit cell; wearable electromagnetic imaging; Wearable technology; wideband antenna
• ISSN: 1932-4545; 1940-9990; 1940-9990
• DOI: 10.1109/TBCAS.2018.2878057

Given the increased interest in a fast, portable, and on-spot medical diagnostic tool that enables early diagnosis for patients with brain stroke, a new approach of a wearable electromagnetic head imaging system based on the polymer material is proposed. A flexible low-profile, wideband, and unidirectional antenna array with electromagnetic band gap (EBG) and metamaterial (MTM) unit cells reflector is utilized. The designed antenna consists of a 4 × 4 radiating patch loaded with symmetrical extended open-ended U-slots and fed by combination of series and corporate transmission lines. A mushroom-like 10-EBG unit cell arrays are arranged around the feeding network to reduce surface waves, whereas 4 × 4 MTM unit cells are placed on the back-side of the antenna to enable unidirectional radiation. The antenna is designed and embedded on a multilayer low cost, low loss, transparent, and robust polymer poly-di-methyl-siloxane (PDMS) substrate and optimized to operate in contact with the human head. The simulated and measured results show that the antenna has a fractional bandwidth of 53.8% (1.16-1.94 GHz), more than 80% of radiation efficiency, and satisfactory field penetration in the head tissues with a safe specific absorption rate. An eight-element array is then configured on 300 × 360 × 4.1 mm 3 PDMS material covering an average human head size and used as a worn part of the imaging system. A realistic-shaped 3-D specific anthropomorphic mannequin (SAM) head phantom is used to verify the performance of the designed array. The imaging results indicate the possibility of using the designed conformal array to detect a bleeding inside the brain using a confocal image algorithm.