{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,1]],"date-time":"2026-09-01T15:04:16Z","timestamp":1788275056654,"version":"build-2803163510"},"reference-count":16,"publisher":"MDPI AG","issue":"18","license":[{"start":{"date-parts":[[2021,9,7]],"date-time":"2021-09-07T00:00:00Z","timestamp":1630972800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Intra-abdominal hypertension, defined as an intra-abdominal pressure (IAP) equal to or above 12 mmHg is one of the major risk-factors for increased morbidity (organ failure) and mortality in critically ill patients. Therefore, IAP monitoring is highly recommended in intensive care unit (ICU) patients to predict development of abdominal compartment syndrome and to provide a better care for patients hospitalized in the ICU. The IAP measurement through the bladder is the actual reference standard advocated by the abdominal compartment society; however, this measurement technique is cumbersome, non-continuous, and carries a potential risk for urinary tract infections and urethral injury. Using microwave reflectometry has been proposed as one of the most promising IAP measurement alternatives. In this study, a novel radar-based method known as transient radar method (TRM) has been used to monitor the IAP in an in vitro model with an advanced abdominal wall phantom. In the second part of the study, further regression analyses have been done to calibrate the TRM system and measure the absolute value of IAP. A correlation of \u20130.97 with a p-value of 0.0001 was found between the IAP and the reflection response of the abdominal wall phantom. Additionally, a quadratic relation with a bias of \u22120.06 mmHg was found between IAP obtained from the TRM technique and the IAP values recorded by a pressure gauge. This study showed a promising future for further developing the TRM technique to use it in clinical monitoring.<\/jats:p>","DOI":"10.3390\/s21185999","type":"journal-article","created":{"date-parts":[[2021,9,8]],"date-time":"2021-09-08T02:41:07Z","timestamp":1631068867000},"page":"5999","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":13,"title":["Non-Invasive Intra-Abdominal Pressure Measurement by Means of Transient Radar Method: In Vitro Validation of a Novel Radar-Based Sensor"],"prefix":"10.3390","volume":"21","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-6751-1858","authenticated-orcid":false,"given":"Salar","family":"Tayebi","sequence":"first","affiliation":[{"name":"Department of Electronics and Informatics, Vrije Universiteit Brussel, 1050 Brussels, Belgium"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ali","family":"Pourkazemi","sequence":"additional","affiliation":[{"name":"Department of Electronics and Informatics, Vrije Universiteit Brussel, 1050 Brussels, Belgium"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1816-5255","authenticated-orcid":false,"given":"Manu L.N.G.","family":"Malbrain","sequence":"additional","affiliation":[{"name":"First Department of Anaesthesiology and Intensive Therapy, Medical University of Lublin, 20-059 Lublin, Poland"},{"name":"Medical Department, Medical Direction, AZ Jan Palfijn, 9000 Ghent, Belgium"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Johan","family":"Stiens","sequence":"additional","affiliation":[{"name":"Department of Electronics and Informatics, Vrije Universiteit Brussel, 1050 Brussels, Belgium"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2021,9,7]]},"reference":[{"key":"ref_1","first-page":"83","article-title":"Update from the Abdominal Compartment Society (WSACS) on intra-abdominal hypertension and abdominal compartment syndrome: Past, present, and future beyond Banff 2017","volume":"49","author":"Kirkpatrick","year":"2017","journal-title":"Anestezjol. Intensywna Ter."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"822","DOI":"10.1007\/s00134-004-2169-9","article-title":"Prevalence of intra-abdominal hypertension in critically ill patients: A multicentre epidemiological study","volume":"30","author":"Malbrain","year":"2004","journal-title":"Intensive Care Med."},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Muturi, A., Ndaguatha, P., Ojuka, D., and Kibet, A. (2016). Prevalence and predictors of intra-abdominal hypertension and compartment syndrome in surgical patients in critical care units at Kenyatta National Hospital. BMC Emerg. Med., 17.","DOI":"10.1186\/s12873-017-0120-y"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"57","DOI":"10.1186\/s13017-015-0051-4","article-title":"Intra-abdominal hypertension; prevalence, incidence and outcomes in a low resource setting; a prospective observational study","volume":"10","author":"Kuteesa","year":"2015","journal-title":"World J. Emerg. Surg."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"963","DOI":"10.1111\/aogs.13898","article-title":"Intra-abdominal pressure as an ignored parameter in the pathophysiology of preeclampsia","volume":"99","author":"Gyselaers","year":"2020","journal-title":"Acta Obstet. Gynecol. Scand."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"26","DOI":"10.1179\/acb.2007.62.s1.005","article-title":"Continuous Intra-Abdominal Pressure Monitoring","volume":"62","author":"Balogh","year":"2007","journal-title":"Acta Clin. Belg."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"16","DOI":"10.1179\/acb.2007.62.s1.004","article-title":"Rational Intraabdominal Pressure Monitoring: How to Do it?","volume":"62","author":"Malbrain","year":"2007","journal-title":"Acta Clin. Belg."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"51","DOI":"10.1007\/s10877-020-00561-4","article-title":"A concise overview of non-invasive intra-abdominal pressure measurement techniques: From bench to bedside","volume":"35","author":"Tayebi","year":"2021","journal-title":"J. Clin. Monit."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1190","DOI":"10.1007\/s00134-013-2906-z","article-title":"Intra-abdominal hypertension and the abdominal compartment syndrome: Updated consensus definitions and clinical practice guidelines from the World Society of the Abdominal Compartment Syndrome","volume":"39","author":"Kirkpatrick","year":"2013","journal-title":"Intensive Care Med."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"345","DOI":"10.1007\/s00134-012-2804-9","article-title":"Year in review in Intensive Care Medicine 2012. II: Pneumonia and infection, sepsis, coagulation, hemodynamics, cardiovascular and microcirculation, critical care organization, imaging, ethics and legal issues","volume":"39","author":"Antonelli","year":"2013","journal-title":"Intensive Care Med."},{"key":"ref_11","first-page":"1","article-title":"Non-invasive indirect monitoring of intra-abdominal pressure using microwave reflectometry: System design and proof-of-concept clinical trial","volume":"14","author":"David","year":"2020","journal-title":"J. Clin. Monit."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1109\/TMTT.2017.2665633","article-title":"Transient Radar Method: Novel Illumination and Blind Electromagnetic\/Geometrical Parameter Extraction Technique for Multilayer Structures","volume":"65","author":"Pourkazemi","year":"2017","journal-title":"IEEE Trans. Microw. Theory Tech."},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Pourkazemi, A., Tayebi, S., and Stiens, J.H. (2020). Error Assessment and Mitigation Methods in Transient Radar Method. Sensors, 20.","DOI":"10.3390\/s20010263"},{"key":"ref_14","unstructured":"Pourkazemi AStiens, J. (2015). Characterization of Multilayer Structures. (EP 3 106 861 A1), European Patent."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"203","DOI":"10.1179\/acb.2009.036","article-title":"Recommendations for Research from the International Conference of Experts on Intra-Abdominal Hypertension and Abdominal Compartment Syndrome","volume":"64","author":"Cheatham","year":"2009","journal-title":"Acta Clin. Belg."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1186\/s13054-016-1220-x","article-title":"The neglected role of abdominal compliance in organ-organ interactions","volume":"20","author":"Malbrain","year":"2016","journal-title":"Crit. 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