In this letter a 3D printed compact UWB extended gap ridge horn (EGRH) antenna designed to be used for biological measurements of the human body is described. The operational frequency covers the microwave band of interest from 0.5 to 3.0 GHz (for a S11 under -7dB). The 3D printed EGRH antenna is dielectrically matched to the permittivity of the human body and because of its compactness it can be visualized as a general purpose microwave probe among the RF biomedical community. The probe has proven its capability as a pass-through propagation sensor for different parts of the human body and as a sensor detecting a 1 cm diameter object placed inside an artificial head phantom.

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A system to integrate microwave imaging with optical colonoscopy is presented. The overarching goal is to improve the prevention and early diagnosis of one of the main health and economic burdens of an increasingly aging population, i.e., colorectal cancer. For a colonoscopy, the gold standard for colorectal cancer diagnosis, 22% of polyps are not detected, and the risk of cancer after a negative colonoscopy can be up to 7.9%. To remedy this, a microwave imaging system able to generate an alarm when a polyp is detected is designed, manufactured and validated with a colon phantom composed of tissue-mimicking oil-gelatin materials reproducing the anatomy and dielectric properties of a human colon with a polyp. The acquisition was performed by a miniaturized ring-shaped switched array of 16 antennas attachable at the tip of a conventional colonoscope. This has been conceived to satisfy endoscopy size restrictions, patient safety and intercompatibility with current clinical practice. A Modified Monofocusing imaging method preceded by a previous frame average subtraction as a calibration technique shows a perfect detection of a 10-mm polyp (100% sensitivity and specificity) in the eight analyzed trajectories. The phantom results demonstrate the feasibility of the system in future preclinical trials.

Introduction. Microwave imaging can obtain 360° anatomical and functional images of the colon representing the existing contrast in dielectric properties between different tissues. Microwaves are safe (nonionizing) and have the potential of reducing the visualization problems of conventional colonoscopy. This study assessed the efficacy of a microwave-based colonoscopy device to detect neoplastic lesions in an ex vivo human colon model. Methods. Fresh surgically excised colorectal specimens containing cancer or polyps were fixed to a 3D positioning system, and the accessory device was introduced horizontally inside the ex vivo colon lumen and moved along it simulating a real colonoscopy exploration. Measurements of the colon were taken every 4 mm with the microwave-based colonoscopy device and processed with a microwave imaging algorithm. Results. 14 ex vivo human colorectal specimens with carcinomas ( n = 11 ) or adenomas with high grade dysplasia ( n = 3 ) were examined with a microwave-based device. Using a detection threshold of 2.79 for the dielectric property contrast, all lesions were detected without false positives or false negatives. Conclusions. This study demonstrates the use of a microwave-based device to be used as an accessory of a standard colonoscope to detect neoplastic lesions in surgically excised colorectal specimens.

A system to integrate microwave imaging with optical colonoscopy is presented. The overarching goal is to improve the prevention, diagnosis and understanding of one of the main health and economic burdens of an increasingly ageing population that is colorectal cancer. Our system can address the two main challenges of colonoscopy – improve the detection of precancerous lesions called polyps and classify them according to their malignancy – and moves forward a major trend of the field that is automating medical explorations. To do so, a complete imaging system able to emit an alarm when a polyp is detected is designed, manufactured and validated with a realistic colon phantom composed by tissue-mimicking oil-gelatin materials reproducing the anatomy and dielectric properties of a human colon with a polyp. The acquisition is done by a miniaturized ring-shaped switched array of 16 antennas attachable at the tip of a conventional colonoscope. It has been conceived to satisfy endoscopy size restrictions, patient safety and intercompatibility with the current clinical practice. A Modified Monofocusing imaging method preceded by a previous frame average subtraction as calibration technique shows perfect detection of a 10-mm polyp (100% sensitivity and specificity) in the two analyzed trajectories. Results of realistic phantom demonstrate the feasibility of the system in future preclinical trials.