In vivo static imaging for the real and the reactive parts in electrical impedance tomography using multifrequency techniques

Multifrequency measurements in electrical impedance tomography are a viable alternative to absolute measurements for obtaining images from static structures inside the human body. If two fixed frequencies are used, however, it may happen that we cannot discriminate different tissues because of a similar impedance (or admittance) variation for that given frequency pair. A frequency sweep would help to discriminate different tissues, according to widely accepted models for impedance variation with frequency. An alternative to a frequency sweep is imaging both the real and the reactive parts of the impedance (or admittance), because for a given tissue both parts can have a different frequency dependance. In this work we present some images obtained in the human body for the real and the reactive part of the impedance using two different frequencies.

[1]  D. Isaacson Distinguishability of Conductivities by Electric Current Computed Tomography , 1986, IEEE Transactions on Medical Imaging.

[2]  R Gadd,et al.  Multifrequency electrical impedance tomography. , 1992, Clinical physics and physiological measurement : an official journal of the Hospital Physicists' Association, Deutsche Gesellschaft fur Medizinische Physik and the European Federation of Organisations for Medical Physics.

[3]  K. Foster,et al.  Dielectric properties of tissues and biological materials: a critical review. , 1989, Critical reviews in biomedical engineering.

[4]  D C Barber,et al.  Theoretical limits to sensitivity and resolution in impedance imaging. , 1987, Clinical physics and physiological measurement : an official journal of the Hospital Physicists' Association, Deutsche Gesellschaft fur Medizinische Physik and the European Federation of Organisations for Medical Physics.

[5]  P J Riu,et al.  A broadband system for multifrequency static imaging in electrical impedance tomography. , 1992, Clinical physics and physiological measurement : an official journal of the Hospital Physicists' Association, Deutsche Gesellschaft fur Medizinische Physik and the European Federation of Organisations for Medical Physics.

[6]  David Isaacson,et al.  Thoracic Impedance Images During Ventilation , 1990, [1990] Proceedings of the Twelfth Annual International Conference of the IEEE Engineering in Medicine and Biology Society.