%0 Journal Article %1 9860064 %A Veil, Carina %A Müller, Daniel %A Walz, Simon %A Schüle, Johannes %A Somers, Peter %A Tarín, Cristina %A Stenzl, Arnulf %A Sawodny, Oliver %D 2023 %J IEEE Transactions on Biomedical Engineering %K arnulf_stenzl carina_veil grk2543 johannes_schuele journal oliver_sawodny peter_somers reviewed simon_walz %N 2 %P 650-658 %R 10.1109/TBME.2022.3199468 %T Enhancing Tissue Impedance Measurements Through Modeling of Fluid Flow During Viscoelastic Relaxation %V 70 %X Objective: Bladder cancer recurrence is an important issue after endoscopic urological surgeries. Additional sensor information such as electrical impedance measurements aim to support surgeons to ensure that the entirety of the tumor is removed. The foundation for differentiating lies in the altered sodium contents and cell structures within tumors that change their conductivity and permittivity. Mechanical deformations in the tissue expel fluid from the compressed area and pose a great difficulty, as they also lead to impedance changes. It is crucial to determine if this effect outweighs the alterations due to the tumorous tissue properties. Methods: Impedance measurements under ongoing viscoelastic relaxation are taken on healthy and tumorous tissue samples from human bladders and breasts. A fluid model to account for extra- and intracellular fluid flow under compression is derived. It is based on the fluid content within the individual tissue compartments and their outflow via diffusion. Results: After an initial deformation, the tissue relaxes and the impedance increases. The proposed model accurately represents these effects and validates the link between fluid flow under mechanical deformation and its impact on tissue impedance. A method to compensate for these undesired effects of fluid flow is proposed and the measurements are assessed in terms of differentiability between tumorous and healthy tissue samples. Conclusion: The electrical parameters are found to be promising for differentiation even under varying mechanical deformation, and the distinction is additionally improved by the proposed compensation approach. Significance: Electrical impedance measurements show great potential to support urologist during endoscopic surgeries.

@article{9860064, abstract = {Objective: Bladder cancer recurrence is an important issue after endoscopic urological surgeries. Additional sensor information such as electrical impedance measurements aim to support surgeons to ensure that the entirety of the tumor is removed. The foundation for differentiating lies in the altered sodium contents and cell structures within tumors that change their conductivity and permittivity. Mechanical deformations in the tissue expel fluid from the compressed area and pose a great difficulty, as they also lead to impedance changes. It is crucial to determine if this effect outweighs the alterations due to the tumorous tissue properties. Methods: Impedance measurements under ongoing viscoelastic relaxation are taken on healthy and tumorous tissue samples from human bladders and breasts. A fluid model to account for extra- and intracellular fluid flow under compression is derived. It is based on the fluid content within the individual tissue compartments and their outflow via diffusion. Results: After an initial deformation, the tissue relaxes and the impedance increases. The proposed model accurately represents these effects and validates the link between fluid flow under mechanical deformation and its impact on tissue impedance. A method to compensate for these undesired effects of fluid flow is proposed and the measurements are assessed in terms of differentiability between tumorous and healthy tissue samples. Conclusion: The electrical parameters are found to be promising for differentiation even under varying mechanical deformation, and the distinction is additionally improved by the proposed compensation approach. Significance: Electrical impedance measurements show great potential to support urologist during endoscopic surgeries.}, added-at = {2023-06-26T13:27:05.000+0200}, author = {Veil, Carina and Müller, Daniel and Walz, Simon and Schüle, Johannes and Somers, Peter and Tarín, Cristina and Stenzl, Arnulf and Sawodny, Oliver}, biburl = {https://puma.ub.uni-stuttgart.de/bibtex/2030a093f3cb0d6d5f8788c18c1a20be1/ffischer}, doi = {10.1109/TBME.2022.3199468}, interhash = {dea8495976f0feb57402d4b5401dd0d2}, intrahash = {030a093f3cb0d6d5f8788c18c1a20be1}, issn = {1558-2531}, journal = {IEEE Transactions on Biomedical Engineering}, keywords = {arnulf_stenzl carina_veil grk2543 johannes_schuele journal oliver_sawodny peter_somers reviewed simon_walz}, month = feb, number = 2, pages = {650-658}, timestamp = {2023-08-10T10:14:20.000+0200}, title = {Enhancing Tissue Impedance Measurements Through Modeling of Fluid Flow During Viscoelastic Relaxation}, volume = 70, year = 2023 }