Improving sensitivity in the deep regions of a volume conductor using electrical focused impedance methods
Bioimpedance measurements are becoming important in probing the human body for diagnosis and monitoring. An age old 4-electrode technique called tetrapolar impedance measurement (TPIM), giving transfer impedance, cannot localize a specific zone besides having large zones of negative sensitivity. A n...
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2024-09-01
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| Series: | Journal of Electrical Bioimpedance |
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| Online Access: | https://doi.org/10.2478/joeb-2024-0012 |
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| author | Mobarak Mahjabin Rabbani K Siddique-e |
| author_facet | Mobarak Mahjabin Rabbani K Siddique-e |
| author_sort | Mobarak Mahjabin |
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| description | Bioimpedance measurements are becoming important in probing the human body for diagnosis and monitoring. An age old 4-electrode technique called tetrapolar impedance measurement (TPIM), giving transfer impedance, cannot localize a specific zone besides having large zones of negative sensitivity. A new technique named the focused impedance method (FIM) from Dhaka University (DU), Bangladesh used the algebraic average of two concentric and orthogonal TPIMs, localizing a zone of interest and having reduced magnitudes of negative sensitivity. Earlier, this was implemented with electrodes applied from one side of the human body giving information to shallow depths only. To get information from deeper regions, specifically, of the thorax, the same DU group placed two electrodes of a 4-electrode version of FIM at the front and two at the back in a horizontal plane of the thorax, using physics-based visualization. This was followed by a few quantitative studies using point sensitivity, which supported the concept. However, more quantitative studies still need to be performed, particularly using objects of finite sizes, in order to establish the technique on a stronger footing. The present study was taken up with this objective. A simplified approach was used in which the volume conductor was a rectangular non-conducting container filled with saline of uniform conductivity with an embedded spherical object – first an insulator and then a conductor. Electrodes were placed at specific chosen positions following the above visualization. Percentage change in transfer impedance with the object placed at different internal positions, compared to that without the object was obtained first using COMSOL simulation and then through experimental measurements. These were performed for both TPIM and FIM. The new configuration of 4-electrode FIM gave good depth sensitivity supporting the effectiveness of the new placement of electrodes. |
| format | Article |
| id | doaj-art-705ca501d05e441dab39bf2e89a13cac |
| institution | Kabale University |
| issn | 1891-5469 |
| language | English |
| publishDate | 2024-09-01 |
| publisher | Sciendo |
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| series | Journal of Electrical Bioimpedance |
| spelling | doaj-art-705ca501d05e441dab39bf2e89a13cac2025-01-20T11:09:56ZengSciendoJournal of Electrical Bioimpedance1891-54692024-09-0115110711510.2478/joeb-2024-0012Improving sensitivity in the deep regions of a volume conductor using electrical focused impedance methodsMobarak Mahjabin0Rabbani K Siddique-e11Southeast University, Dhaka, Bangladesh2Department of Biomedical Physics and Technology, University of Dhaka, Dhaka, BangladeshBioimpedance measurements are becoming important in probing the human body for diagnosis and monitoring. An age old 4-electrode technique called tetrapolar impedance measurement (TPIM), giving transfer impedance, cannot localize a specific zone besides having large zones of negative sensitivity. A new technique named the focused impedance method (FIM) from Dhaka University (DU), Bangladesh used the algebraic average of two concentric and orthogonal TPIMs, localizing a zone of interest and having reduced magnitudes of negative sensitivity. Earlier, this was implemented with electrodes applied from one side of the human body giving information to shallow depths only. To get information from deeper regions, specifically, of the thorax, the same DU group placed two electrodes of a 4-electrode version of FIM at the front and two at the back in a horizontal plane of the thorax, using physics-based visualization. This was followed by a few quantitative studies using point sensitivity, which supported the concept. However, more quantitative studies still need to be performed, particularly using objects of finite sizes, in order to establish the technique on a stronger footing. The present study was taken up with this objective. A simplified approach was used in which the volume conductor was a rectangular non-conducting container filled with saline of uniform conductivity with an embedded spherical object – first an insulator and then a conductor. Electrodes were placed at specific chosen positions following the above visualization. Percentage change in transfer impedance with the object placed at different internal positions, compared to that without the object was obtained first using COMSOL simulation and then through experimental measurements. These were performed for both TPIM and FIM. The new configuration of 4-electrode FIM gave good depth sensitivity supporting the effectiveness of the new placement of electrodes.https://doi.org/10.2478/joeb-2024-0012electrical impedancetetrapolar impedance method (tpim)focused impedance method (fim)transfer impedancedeep probing of thorax |
| spellingShingle | Mobarak Mahjabin Rabbani K Siddique-e Improving sensitivity in the deep regions of a volume conductor using electrical focused impedance methods Journal of Electrical Bioimpedance electrical impedance tetrapolar impedance method (tpim) focused impedance method (fim) transfer impedance deep probing of thorax |
| title | Improving sensitivity in the deep regions of a volume conductor using electrical focused impedance methods |
| title_full | Improving sensitivity in the deep regions of a volume conductor using electrical focused impedance methods |
| title_fullStr | Improving sensitivity in the deep regions of a volume conductor using electrical focused impedance methods |
| title_full_unstemmed | Improving sensitivity in the deep regions of a volume conductor using electrical focused impedance methods |
| title_short | Improving sensitivity in the deep regions of a volume conductor using electrical focused impedance methods |
| title_sort | improving sensitivity in the deep regions of a volume conductor using electrical focused impedance methods |
| topic | electrical impedance tetrapolar impedance method (tpim) focused impedance method (fim) transfer impedance deep probing of thorax |
| url | https://doi.org/10.2478/joeb-2024-0012 |
| work_keys_str_mv | AT mobarakmahjabin improvingsensitivityinthedeepregionsofavolumeconductorusingelectricalfocusedimpedancemethods AT rabbaniksiddiquee improvingsensitivityinthedeepregionsofavolumeconductorusingelectricalfocusedimpedancemethods |