An improved data acquisition method for electrical impedance tomography
| Autor: | K. Sunshine Osterman, Alex Hartov, Christine DeLorenzo, Todd E Kerner, Keith D. Paulsen |
|---|---|
| Rok vydání: | 2001 |
| Předmět: |
Adult
Male Leg Materials science Physiology Acoustics Biomedical Engineering Biophysics Impulse (physics) Sensitivity and Specificity Data acquisition Physiology (medical) Electrode Electrode array Electronic engineering Electric Impedance Image Processing Computer-Assisted Humans Computer Simulation Spatial frequency Electrical impedance tomography Electrodes Tomography Excitation Voltage |
| Zdroj: | Physiological measurement. 22(1) |
| ISSN: | 0967-3334 |
| Popis: | Isaacson, Cheney and Seager have demonstrated that simultaneously applying trigonometric patterns of current to a circular electrode array optimizes the sensitivity of EIT to inner structure. We have found that it is less desirable to measure voltage at an electrode that also applies a current due to variable contact impedance. In order to preserve the optimum sensitivity while minimizing the effect of electrode artefacts, we have devised an approach where we sequentially apply a current between each individual electrode and a separate, fixed ground while measuring voltages at all other electrodes for each consecutive current impulse. By adding weighted sums of both the applied currents and corresponding measured voltages from individual passes, we can synthesize trigonometric patterns of any spatial frequency. Since only one of the electrodes in any given acquired data set is used as a source, this approach significantly dilutes the effect of contact impedance on the resulting voltage measurements. We present simulated data showing the equivalency between the synthesized and actual trigonometric excitation patterns. In addition, we report experimental data, both in vitro and in vivo, that show improved results using this data acquisition technique. |
| Databáze: | OpenAIRE |
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