Electromagnetic radiation from ingested sources in the human intestine between 150 MHz and 1.2 GHz

Chirwa, L.C., Hammond, P.A., Roy, S. and Cumming, D.R.S. (2003) Electromagnetic radiation from ingested sources in the human intestine between 150 MHz and 1.2 GHz. IEEE Transactions on Biomedical Engineering, 50(4), pp. 484-492. (doi: 10.1109/TBME.2003.809474)

Abstract

The conventional method of diagnosing disorders of the human gastro-intestinal (GI) tract is by sensors embedded in cannulae that are inserted through the anus, mouth, or nose. However, these cannulae cause significant patient discomfort and cannot be used in the small intestine. As a result, there is considerable ongoing work in developing wireless sensors that can be used in the small intestine. The radiation characteristics of sources in the GI tract cannot be readily calculated due to the complexity of the human body and its composite tissues, each with different electrical characteristics. In addition, the compact antennas used are electrically small, making them inefficient radiators. This paper presents radiation characteristics for sources in the GI tract that should allow for the optimum design of more efficient telemetry systems. The characteristics are determined using the finite-difference time-domain method with a realistic antenna model on an established fully segmented human body model. Radiation intensity outside the body was found to have a Gaussian-form relationship with frequency. Maximum radiation occurs between 450 and 900 MHz. The gut region was found generally to inhibit vertically polarized electric fields more than horizontally polarized fields.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Cumming, Professor David
• Authors: Chirwa, L.C., Hammond, P.A., Roy, S., and Cumming, D.R.S.
• Subjects: T Technology > TK Electrical engineering. Electronics Nuclear engineering
• College/School: College of Science and Engineering > School of Engineering > Electronics and Nanoscale Engineering
• Research Group: Device Modelling Group
• Journal Name: IEEE Transactions on Biomedical Engineering
• Publisher: Institute of Electrical and Electronics Engineers
• ISSN: 0018-9294
• Copyright Holders: Copyright © 2003 Institute of Electrical and Electronics Engineers
• First Published: First published in IEEE Transactions on Biomedical Engineering 50(4):484-492
• Publisher Policy: Reproduced in accordance with the copyright policy of the publisher