Influence of current injection pattern and electric potential measurement strategies in electrical impedance tomography
| Autor: | Renato Seiji Tavares, Olavo Luppi Silva, Marcos de Sales Guerra Tsuzuki, Raul Gonzalez Lima, Fernando Silva de Moura, Thiago de Castro Martins |
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| Rok vydání: | 2017 |
| Předmět: |
Materials science
Applied Mathematics Acoustics 0206 medical engineering 02 engineering and technology Iterative reconstruction Inverse problem Impedance parameters 020601 biomedical engineering 030218 nuclear medicine & medical imaging Computer Science Applications 03 medical and health sciences 0302 clinical medicine Control and Systems Engineering Linearization Electronic engineering Electric potential Electrical and Electronic Engineering Electric current Current (fluid) Electrical impedance tomography |
| Zdroj: | Control Engineering Practice. 58:276-286 |
| ISSN: | 0967-0661 |
| Popis: | Electrical Impedance Tomography (EIT) is a non-invasive image reconstruction technique, whereby current is injected by electrodes and electric potential is measured by electrodes. In some electronic hardware implementations, only two electrodes inject current simultaneously, and are denominated pair-wise current injection. Several possibilities of pair-wise current injection (electric current patterns) and electric potential measurement (single-ended and differential) have been addressed in the literature. Considering pair-wise current injection, the skip-m current pattern can be defined as a pair-wise injection strategy in which the number of non-current injecting electrodes enclosed between two injection electrodes is m. Single-ended electric potential measurements consist of measurements with a common potential reference. Differential electric potential measurements consist of pair-wise measurements between two electrodes. A theoretical analysis based on control theory is presented to show that some current and measurement pattern strategies convey less information than others. This hypothesis is verified by the analysis of the matrix containing possible measurement vectors, with respect to its rank, condition number and singular values. Additionally, a novel approach is proposed to analyse current and measurement patterns based on uncertainty estimation of difference images by the correlation matrix linearization of the reconstructed impedance matrix. The results show that single-ended potential measurements are usually better when compared to differential electric potential measurements. A conclusion supported by both points of view is that the cross current pattern (diametral) is the least informative for these symmetrical domains. |
| Databáze: | OpenAIRE |
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