Georgetown University

William D Gregory

Larry H Capots

Luigi Morelli

Richard Janik

James P George

Pictorial images of selected volume elements of materials are generated by a contactless, non-destructive, substantially hazard free tomographic technique in which the material is brought within the influence of a relatively low-strength electromagnetic field and subjected to plural preselected frequencies to provide output data which is used to generate an image reflective of the magnetic and/or electric and/or conductance properties of the selected volume elements. This data has a high volume information content which enables accurate and reproducible identification of the material under investigation. The technique has application in the medical diagnostic field such as for example in aiding in the detection of small areas of cancerous tissue present in a larger mass of healthy tissue.

Apparatus and method for image reproduction of materials using their

The non-linear conductance and capacitance characteristics of electrically non-homogenous materials over a given frequency range are used to identify and analyze such materials.

Identification of materials using their complex dielectric response

The type of conductor, its property, and if a metal, its type and cross-sectional area can be obtained from measurements made at different frequencies for the amount of unbalance created in a previously balanced stable coil detection system. The true resistive component is accurately measured and thus reflects only the voltage loss attributable to eddy currents caused by introduction of the test sample to the coil system. This voltage divided by corresponding applied frequency gives a curve which peaks at a frequency dependent upon type of conductor. For a metal this peak frequency is proportional to the samples resistivity divided by its cross-sectional area.

Growing community of inventors

Vienna, VA, United States of America

William D Gregory