U.S. flag

An official website of the United States government, Department of Justice.

Compact, Low-Cost Body Cavity Screening Device

NCJ Number
Erik Magnuson
Date Published
January 2013
54 pages
Electronic field tomography (EFT) was investigated as a method for developing a low-cost, non-invasive device to use in screening body cavities for concealed contraband.
Initial detection and operational requirements were developed from discussions with personnel in the California Department of Corrections as well as their counterparts in the Western United States. A laboratory prototype system was developed with fixed receive and transmit nodes. Images were reconstructed from both experimental and simulated data and were shown to be in good agreement. In order to overcome the inherent low resolution of EFT, a novel multi-frequency method was developed. Images acquired over the frequency range of 1 MHz to 20 MHz were used to build a linear model and decompose the different object types in the image, e.g., muscle, bone, plastic. The feasibility of the multi-frequency EFT method was demonstrated with simulated data and then with actual images. The designs for a new prototype using switching transceiver nodes were finalized. The method thus shows promise for the use of EFT as a detector of foreign objects within a non-uniform body tissue background despite the inherent low resolution of EFT images. The next phase of this project will fabricate, debug, and implement the transceiver electronics on a laboratory prototype, validate its operation on phantoms simulating human tissue and contrabands, and finally test it on human subjects (without concealed contraband). 56 figures

Date Published: January 1, 2013