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Assessment of small intestinal viability: A bioimpedance approach

Strand-Amundsen, Runar J.
Doctoral thesis
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PhD-Strand-Amundsen-2019.pdf (7.010Mb)
Year
2019
Permanent link
http://urn.nb.no/URN:NBN:no-70836

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  • Fysisk institutt [2515]
Abstract
This thesis describes how bioimpedance measurements can be used to assess the viability (live or die) of the small intestines, after a period without sufficient blood supply (ischemia). Using machine learning we were able to classify intestinal tissue injury and viability based on bioimpedance data, with accuracies similar to or better than what is reported by using the present clinical method.

The thesis describes how electrical parameters measured on the small intestine change during ischemia and reperfusion and describes the creation of a reference model for intestinal viability in a pig model. It also discusses how machine learning can be a relevant tool for analysis of longitudinal bioimpedance data.

As a part of the methodology, the thesis discusses intraluminal microdialysis for detection and monitoring of ischemia and reperfusion, and the use of histology to provide a reference for the viability limit. The thesis combines knowledge and research from the fields of physics and medicine, in order to investigate a solution to a medical problem.
List of papers
Paper I: R. J. Strand-Amundsen, C. Tronstad, H. Kalvøy, Y. Gundersen, C. D. Krohn, A. O. Aasen, L. Holhjem, H. M. Reims, Ø. G. Martinsen, J. O. Høgetveit, T. E. Ruud and T. I. Tønnessen. In-vivo characterization of ischemic small intestine using bioimpedance measurements Physiological measurement. 37 (2) (2016). doi:10.1088/0967-3334/37/2/257. The paper is not available in DUO due to publisher restrictions. The published version is available at: https://doi.org/10.1088/0967-3334/37/2/257
Paper II: R. J. Strand-Amundsen, H. M. Reims, C. Tronstad, H. Kalvøy, Ø. G. Martinsen, J. O. Høgetveit, T. E. Ruud and T. I. Tønnessen. Ischemic small intestine – In-vivo versus ex-vivo bioimpedance measurements. Physiological measurement. 38 (5) (2017). DOI: 10.1088/1361-6579/aa67b7 The paper is not available in DUO due to publisher restrictions. The published version is available at: https://doi.org/10.1088/1361-6579/aa67b7
Paper III: R. J. Strand-Amundsen, C. Tronstad, H. Kalvøy, T. E. Ruud, J. O. Høgetveit, Ø. G. Martinsen and T. I. Tønnessen. Small intestinal ischemia and reperfusion—Bioimpedance measurements. Physiological measurement. 39 (2) (2018). DOI: 10.1088/1361-6579/aaa576 The paper is not available in DUO due to publisher restrictions. The published version is available at: https://doi.org/10.1088/1361-6579/aaa576
Paper IV: R. J. Strand-Amundsen, H. M. Reims, F. P. Reinholt, T. E. Ruud, R. Yang, J. O. Høgetveit and T. I. Tønnessen. Ischemia/Reperfusion Injury in Porcine Intestine – Viability Assessment. World J Gastroenterol. 24 (18): 2009-2023 (2018). DOI: 10.3748/wjg.v24.i18.2009. The article is included in the thesis. Also available at: https://doi.org/10.3748/wjg.v24.i18.2009
Paper V: R. J. Strand-Amundsen, C. Tronstad, H. Reims, F. Reinholt, J. O. Høgetveit T. I. Tønnessen. Machine learning for intraoperative prediction of viability in ischemic small intestine. Physiological measurement. 39 (10) (2018). DOI: 10.1088/1361-6579/aae0ea The paper is not available in DUO due to publisher restrictions. The published version is available at: https://doi.org/10.1088/1361-6579/aae0ea
 
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