{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,19]],"date-time":"2026-02-19T23:16:08Z","timestamp":1771542968740,"version":"3.50.1"},"reference-count":31,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2018,7,14]],"date-time":"2018-07-14T00:00:00Z","timestamp":1531526400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100003725","name":"National Research Foundation of Korea","doi-asserted-by":"publisher","award":["2016R1C1B2009798"],"award-info":[{"award-number":["2016R1C1B2009798"]}],"id":[{"id":"10.13039\/501100003725","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Ministry of Science and ICT","award":["COI1807M002"],"award-info":[{"award-number":["COI1807M002"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Chronic monitoring of bladder activity and urine volume is essential for patients suffering from urinary dysfunctions. However, due to the anatomy and dynamics of the bladder, chronic and precise monitoring of bladder activity remains a challenge. Here, we propose a new sensing mechanism that measures the bladder volume using a resistive ladder network with contact switches. Instead of measuring the impedance between the electrode continuously, the proposed sensor provides a digitized output (\u2018on\u2019 or \u2018off\u2019) when the bladder volume reaches a certain threshold value. We present simple proof-of-concept sensors which compare the discrete-mode operation to the continuous-mode operation. In addition, by using multiple pairs of this contact-mode switch in a resistor ladder structure, we demonstrate monitoring of the bladder volume in four discrete steps using an idealized balloon and an ex vivo pig\u2019s bladder. We implemented the resistive ladder network using a conductive polypyrrole\/agarose hydrogel composite which exhibits a Young\u2019s modulus comparable to that of the bladder wall. Compared to the continuous-mode operation, the proposed sensing mechanism is less susceptible to drift due to material degradation and environmental factors.<\/jats:p>","DOI":"10.3390\/s18072288","type":"journal-article","created":{"date-parts":[[2018,7,16]],"date-time":"2018-07-16T04:05:33Z","timestamp":1531713933000},"page":"2288","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":18,"title":["Polypyrrole\/Agarose Hydrogel-Based Bladder Volume Sensor with a Resistor Ladder Structure"],"prefix":"10.3390","volume":"18","author":[{"given":"Mi Kyung","family":"Kim","sequence":"first","affiliation":[{"name":"School of Electrical Engineering, Korea Advanced Institute of Science and Technology, Daejeon 34141, Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Sungwoo","family":"Lee","sequence":"additional","affiliation":[{"name":"School of Electrical Engineering, Korea Advanced Institute of Science and Technology, Daejeon 34141, Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Inug","family":"Yoon","sequence":"additional","affiliation":[{"name":"School of Electrical Engineering, Korea Advanced Institute of Science and Technology, Daejeon 34141, Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Geon","family":"Kook","sequence":"additional","affiliation":[{"name":"School of Electrical Engineering, Korea Advanced Institute of Science and Technology, Daejeon 34141, Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yeon Su","family":"Jung","sequence":"additional","affiliation":[{"name":"School of Electrical Engineering, Korea Advanced Institute of Science and Technology, Daejeon 34141, Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9626-8738","authenticated-orcid":false,"given":"Sarah S. M.","family":"Bawazir","sequence":"additional","affiliation":[{"name":"Biomedical Engineering, Khalifa University, Abu Dhabi 127788, UAE"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Cesare","family":"Stefanini","sequence":"additional","affiliation":[{"name":"Biomedical Engineering, Khalifa University, Abu Dhabi 127788, UAE"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Hyunjoo J.","family":"Lee","sequence":"additional","affiliation":[{"name":"School of Electrical Engineering, Korea Advanced Institute of Science and Technology, Daejeon 34141, Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2018,7,14]]},"reference":[{"key":"ref_1","first-page":"145","article-title":"Mapping the Future for Incontinence Treatment Worldwide","volume":"1","author":"Chancellor","year":"1999","journal-title":"Rev. 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