Conference Paper

Response characterization of the precision open-ended coaxial probe for dielectric spectroscopy of breast tissue

Dept. of Electr. & Comput. Eng., Calgary Univ., Alta., Canada
DOI: 10.1109/APS.2003.1220118 Conference: Antennas and Propagation Society International Symposium, 2003. IEEE, Volume: 4
Source: IEEE Xplore

ABSTRACT

Large-scale dielectric spectroscopy of healthy and diseased breast tissue in the 0.1 to 20 GHz frequency range is currently underway. Open-ended coaxial probes are used as sensors to record the reflection coefficient of the tissue samples. The measured reflection coefficient is converted to the dielectric properties data through a suitable inverse technique. The collected data will aid in further advances of the microwave technology for early breast cancer detection. Thus, it is crucial to ensure the highest possible accuracy and reliability of the tissue measurements.

0 Followers
 · 
5 Reads
  • Source
    • "The open-ended coaxial probe was constructed out of stainless steel without flanges to alleviate measurement errors related to environmental factors associated with in vivo testing. The probe was built out of several sections of coaxial lines, and the final section at the probe aperture is a 2.3 mm borosilicate glass line, hermetically sealed to the stainless steel metal conductors (for additional details see Popovic and Okoniewski (2003)). The borosilicate glass probe does not have a ground plane, and this was done so that a consistent contact with the tissue across the whole aperture of the probe could be achieved (i.e. the contact areas of probes with and without ground planes are 2 cm and 4.5 mm diameter respectively). "
    [Show abstract] [Hide abstract]
    ABSTRACT: To aid in the development of a long-range subcutaneous radio frequency identification tag to monitor the fate of sea lion pups, the dielectric properties of the cranial skin of young female otariids, and possible test subjects of similar size and age, or pigs (Sus scrofa) and sheep (Ovis aries) were obtained over a frequency range of 0.1-10 GHz at the base of their heads where the tag will be implanted. The resulting curves were similar in shape to adult human skin data, but the values were generally lower. Between subjects, variations were noted in all the species. Circuitry for the RF-ID tag is being designed to account for antenna detuning as a result of the lossy media or skin and the variation in dielectric properties.
    Full-text · Article · Nov 2005 · Physiological Measurement
  • Source
    • "A unique deembedding model was determined for each of the probes to achieve the same accuracy levels in spite of dimensional variances. In previous research, a lumped-element approach was adopted for the deembedding model[19],[28]. That approach used lumped elements and transmission lines to capture the heterogenenity of the probe configuration. The derivation of the lumped-element model was limited by our ability to accurately measure the probe's internal dimensions, specifically the dimensions of the airline transition, from the X-ray images and the assumption of perfect axial symmetry of the welding process. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Not Available
    Full-text · Article · Oct 2005 · IEEE Transactions on Microwave Theory and Techniques
  • Source
    • "A unique deembedding model was determined for each of the probes to achieve the same accuracy levels in spite of dimensional variances. In previous research, a lumped-element approach was adopted for the deembedding model[19],[28]. That approach used lumped elements and transmission lines to capture the heterogenenity of the probe configuration. The derivation of the lumped-element model was limited by our ability to accurately measure the probe's internal dimensions, specifically the dimensions of the airline transition, from the X-ray images and the assumption of perfect axial symmetry of the welding process. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Hermetic stainless-steel open-ended coaxial probes have been designed for precision dielectric spectroscopy of biological tissue, such as breast tissue, over the 0.5-20-GHz frequency range. Robust data-processing techniques have also been developed for extracting the unknown permittivity of the tissue under test from the reflection coefficient measured with the precision probe and a vector network analyzer. The first technique, referred to as a reflection-coefficient deembedding method, converts the reflection coefficient measured at the probe's calibration plane to the desired aperture-plane reflection coefficient. The second technique uses a rational function model to solve the inverse problem, i.e., to convert the aperture-plane reflection coefficient to the tissue permittivity. The results of the characterization and validation studies demonstrate that these precision probes, used with the prescribed measurement protocols and data-processing techniques, provide highly accurate and reliable in vivo and ex vivo biological tissue measurements, including breast tissue spectroscopy.
    Full-text · Article · Jun 2005 · IEEE Transactions on Microwave Theory and Techniques
Show more