title: Code-division-multiplexed electrical impedance tomography spectroscopy.
abstract: Electrical impedance tomography uses multiple impedance measurements to image the internal conductivity of an object, such as the human body. Code-division multiplexing is proposed as a new method that can provide simultaneous impedance measurements of the multiple channels. Code division provides clear advantages of a wide frequency range at reduced cost and reduced complexity of sources. A potential drawback is the lack of perfectly orthogonal code sets. This caused an increase of 0.62% in root-mean-square spectral error when two codes were used to record two impedance channels simultaneously on a low-pass filter network. The method described provides images and spectra which are equivalent to the conventional time-multiplexed method, with increases in frequency resolution and measurement speed which may be of benefit in some applications of electrical impedance tomography spectroscopy.
authors.forename: A
authors.initials: A
authors.lastname: McEwan
authors.forename: J
authors.initials: J
authors.lastname: Tapson
authors.forename: A
authors.initials: A
authors.lastname: van Schaik
authors.forename: D S
authors.initials: DS
authors.lastname: Holder