{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,8]],"date-time":"2026-09-08T00:14:26Z","timestamp":1788826466387,"version":"build-2803163510"},"reference-count":44,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2026,1,28]],"date-time":"2026-01-28T00:00:00Z","timestamp":1769558400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100000001","name":"National Science Foundation","doi-asserted-by":"publisher","award":["2122901"],"award-info":[{"award-number":["2122901"]}],"id":[{"id":"10.13039\/100000001","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Arizona State University\u2014Mayo Clinic Team"},{"name":"NIH Catalyze Program","award":["1R61HL173926"],"award-info":[{"award-number":["1R61HL173926"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Acute kidney injury (AKI) affects thousands of hospitalized patients annually, yet early detection remains challenging as serum creatinine elevation lags behind clinical deterioration. Decreased urine output (UO) represents a key diagnostic criterion of AKI, sometimes manifesting hours before biochemical changes; however, current manual monitoring methods are labor-intensive and prone to error. Here, we developed and validated a simple, cost-effective automated urine flow meter using non-contact optical sensors, a peristaltic pump, and microcontroller-based automation for precise, real-time monitoring of urine output in clinical settings, named P-meter. Three successive prototypes (V1, V2, V3) were validated against gold-standard gravimetric measurements over 285 h of testing during animal experiments that required bladder catheterization. Iterative refinement addressed miniaturization challenges, fluid dynamics optimization, and sensor positioning to achieve progressively improved accuracy. The optimized V3 prototype demonstrated further enhanced volumetric precision, stability, and flow accuracy with near-unity linearity vs. reference method (R2 = 0.9889), minimal bias (mean error \u22120.1 mL), and 94.18% agreement within confidence limits (n = 86), outperforming the initial V1 prototype (R2 = 0.9971, mean error \u22121.69 mL, n = 207) and intermediate V2 design (R2 = 0.9941, mean error 3.63 mL, n = 390), primarily in terms of reduced bias and improved agreement. The P-meter offers accurate urine output monitoring at a lower cost than commercial systems, facilitating its use in early AKI detection and thereby improving patient outcomes.<\/jats:p>","DOI":"10.3390\/s26030849","type":"journal-article","created":{"date-parts":[[2026,1,28]],"date-time":"2026-01-28T17:40:22Z","timestamp":1769622022000},"page":"849","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Development and Validation of an Optical Sensor-Based Automated Urine Flow Meter for Real-Time Patient Monitoring"],"prefix":"10.3390","volume":"26","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-1312-6863","authenticated-orcid":false,"given":"Piyush","family":"Hota","sequence":"first","affiliation":[{"name":"School for Engineering of Matter, Transport & Energy, Ira A. Fulton School of Engineering, Tempe, AZ 85287, USA"},{"name":"Department of Nephrology and Hypertension, Mayo Clinic Arizona, 5777 E Mayo Boulevard, Phoenix, AZ 85054, USA"},{"name":"Center for Bioelectronics and Biosensors, Biodesign Institute, Arizona State University, 1001 S McAllister Ave., Tempe, AZ 85287, USA"},{"name":"Medical Devices and Methods Laboratory, Health Futures Center, Arizona State University, 6161 E. Mayo Blvd., Phoenix, AZ 85054, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9488-3075","authenticated-orcid":false,"given":"Adithya Shyamala","family":"Pandian","sequence":"additional","affiliation":[{"name":"Department of Nephrology and Hypertension, Mayo Clinic Arizona, 5777 E Mayo Boulevard, Phoenix, AZ 85054, USA"},{"name":"Center for Bioelectronics and Biosensors, Biodesign Institute, Arizona State University, 1001 S McAllister Ave., Tempe, AZ 85287, USA"},{"name":"Medical Devices and Methods Laboratory, Health Futures Center, Arizona State University, 6161 E. Mayo Blvd., Phoenix, AZ 85054, USA"},{"name":"School of Electrical, Computer, and Energy Engineering, Ira A. Fulton School of Engineering, Tempe, AZ 85287, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2252-0715","authenticated-orcid":false,"given":"Rodrigo E.","family":"Dom\u00ednguez","sequence":"additional","affiliation":[{"name":"Center for Bioelectronics and Biosensors, Biodesign Institute, Arizona State University, 1001 S McAllister Ave., Tempe, AZ 85287, USA"},{"name":"Medical Devices and Methods Laboratory, Health Futures Center, Arizona State University, 6161 E. Mayo Blvd., Phoenix, AZ 85054, USA"},{"name":"Phoenix Children\u2019s Research Institute, Department of Child Health, College of Medicine\u2014Phoenix, University of Arizona, 475 N. 5th St., Phoenix, AZ 85004, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0253-0406","authenticated-orcid":false,"given":"Manni","family":"Mo","sequence":"additional","affiliation":[{"name":"Department of Nephrology and Hypertension, Mayo Clinic Arizona, 5777 E Mayo Boulevard, Phoenix, AZ 85054, USA"},{"name":"Center for Bioelectronics and Biosensors, Biodesign Institute, Arizona State University, 1001 S McAllister Ave., Tempe, AZ 85287, USA"},{"name":"Medical Devices and Methods Laboratory, Health Futures Center, Arizona State University, 6161 E. Mayo Blvd., Phoenix, AZ 85054, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Bo","family":"Fu","sequence":"additional","affiliation":[{"name":"Center for Bioelectronics and Biosensors, Biodesign Institute, Arizona State University, 1001 S McAllister Ave., Tempe, AZ 85287, USA"},{"name":"Medical Devices and Methods Laboratory, Health Futures Center, Arizona State University, 6161 E. Mayo Blvd., Phoenix, AZ 85054, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sandra","family":"Miranda","sequence":"additional","affiliation":[{"name":"Center for Bioelectronics and Biosensors, Biodesign Institute, Arizona State University, 1001 S McAllister Ave., Tempe, AZ 85287, USA"},{"name":"Medical Devices and Methods Laboratory, Health Futures Center, Arizona State University, 6161 E. Mayo Blvd., Phoenix, AZ 85054, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6875-6603","authenticated-orcid":false,"given":"Pinar","family":"Cay-Durgun","sequence":"additional","affiliation":[{"name":"Department of Nephrology and Hypertension, Mayo Clinic Arizona, 5777 E Mayo Boulevard, Phoenix, AZ 85054, USA"},{"name":"Center for Bioelectronics and Biosensors, Biodesign Institute, Arizona State University, 1001 S McAllister Ave., Tempe, AZ 85287, USA"},{"name":"Medical Devices and Methods Laboratory, Health Futures Center, Arizona State University, 6161 E. Mayo Blvd., Phoenix, AZ 85054, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Dheeraj","family":"Sirganagari","sequence":"additional","affiliation":[{"name":"Department of Nephrology and Hypertension, Mayo Clinic Arizona, 5777 E Mayo Boulevard, Phoenix, AZ 85054, USA"},{"name":"Center for Bioelectronics and Biosensors, Biodesign Institute, Arizona State University, 1001 S McAllister Ave., Tempe, AZ 85287, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9228-7480","authenticated-orcid":false,"given":"Michael","family":"Serhan","sequence":"additional","affiliation":[{"name":"Center for Bioelectronics and Biosensors, Biodesign Institute, Arizona State University, 1001 S McAllister Ave., Tempe, AZ 85287, USA"},{"name":"Medical Devices and Methods Laboratory, Health Futures Center, Arizona State University, 6161 E. Mayo Blvd., Phoenix, AZ 85054, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Peter","family":"Serhan","sequence":"additional","affiliation":[{"name":"Center for Bioelectronics and Biosensors, Biodesign Institute, Arizona State University, 1001 S McAllister Ave., Tempe, AZ 85287, USA"},{"name":"Medical Devices and Methods Laboratory, Health Futures Center, Arizona State University, 6161 E. Mayo Blvd., Phoenix, AZ 85054, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0005-1923-2455","authenticated-orcid":false,"given":"Kevin Abi","family":"Karam","sequence":"additional","affiliation":[{"name":"Center for Bioelectronics and Biosensors, Biodesign Institute, Arizona State University, 1001 S McAllister Ave., Tempe, AZ 85287, USA"},{"name":"Medical Devices and Methods Laboratory, Health Futures Center, Arizona State University, 6161 E. Mayo Blvd., Phoenix, AZ 85054, USA"},{"name":"Phoenix Children\u2019s Research Institute, Department of Child Health, College of Medicine\u2014Phoenix, University of Arizona, 475 N. 5th St., Phoenix, AZ 85004, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2581-2243","authenticated-orcid":false,"given":"Naomi M.","family":"Gades","sequence":"additional","affiliation":[{"name":"Department of Comparative Medicine, Mayo Clinic Arizona, 13400 East Shea Boulevard, Scottsdale, AZ 85259, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8917-2607","authenticated-orcid":false,"given":"Peter","family":"Wiktor","sequence":"additional","affiliation":[{"name":"Center for Bioelectronics and Biosensors, Biodesign Institute, Arizona State University, 1001 S McAllister Ave., Tempe, AZ 85287, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0002-2413-1374","authenticated-orcid":false,"given":"Leslie","family":"Thomas","sequence":"additional","affiliation":[{"name":"Department of Nephrology and Hypertension, Mayo Clinic Arizona, 5777 E Mayo Boulevard, Phoenix, AZ 85054, USA"},{"name":"Medical Devices and Methods Laboratory, Health Futures Center, Arizona State University, 6161 E. Mayo Blvd., Phoenix, AZ 85054, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8585-8054","authenticated-orcid":false,"given":"Mary Laura","family":"Lind","sequence":"additional","affiliation":[{"name":"School for Engineering of Matter, Transport & Energy, Ira A. Fulton School of Engineering, Tempe, AZ 85287, USA"},{"name":"Department of Nephrology and Hypertension, Mayo Clinic Arizona, 5777 E Mayo Boulevard, Phoenix, AZ 85054, USA"},{"name":"Center for Bioelectronics and Biosensors, Biodesign Institute, Arizona State University, 1001 S McAllister Ave., Tempe, AZ 85287, USA"},{"name":"Medical Devices and Methods Laboratory, Health Futures Center, Arizona State University, 6161 E. Mayo Blvd., Phoenix, AZ 85054, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2407-8251","authenticated-orcid":false,"given":"Erica","family":"Forzani","sequence":"additional","affiliation":[{"name":"School for Engineering of Matter, Transport & Energy, Ira A. Fulton School of Engineering, Tempe, AZ 85287, USA"},{"name":"Department of Nephrology and Hypertension, Mayo Clinic Arizona, 5777 E Mayo Boulevard, Phoenix, AZ 85054, USA"},{"name":"Center for Bioelectronics and Biosensors, Biodesign Institute, Arizona State University, 1001 S McAllister Ave., Tempe, AZ 85287, USA"},{"name":"Medical Devices and Methods Laboratory, Health Futures Center, Arizona State University, 6161 E. Mayo Blvd., Phoenix, AZ 85054, USA"},{"name":"School of Electrical, Computer, and Energy Engineering, Ira A. Fulton School of Engineering, Tempe, AZ 85287, USA"},{"name":"Phoenix Children\u2019s Research Institute, Department of Child Health, College of Medicine\u2014Phoenix, University of Arizona, 475 N. 5th St., Phoenix, AZ 85004, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,1,28]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"2616","DOI":"10.1016\/S0140-6736(15)60126-X","article-title":"International Society of Nephrology\u2019s 0by25 initiative for acute kidney injury (zero preventable deaths by 2025): A human rights case for nephrology","volume":"385","author":"Mehta","year":"2015","journal-title":"Lancet"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1482","DOI":"10.2215\/CJN.00710113","article-title":"World incidence of AKI: A meta-analysis","volume":"8","author":"Susantitaphong","year":"2013","journal-title":"Clin. J. Am. Soc. Nephrol."},{"key":"ref_3","first-page":"1","article-title":"Kidney disease: Improving global outcomes (KDIGO) acute kidney injury work group. KDIGO clinical practice guideline for acute kidney injury","volume":"2","author":"John","year":"2012","journal-title":"Kidney Int. Suppl."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"R204","DOI":"10.1186\/cc2872","article-title":"Acute Dialysis Quality Initiative Workgroup. Acute renal failure\u2013definition, outcome measures, animal models, fluid therapy and information technology needs: The Second International Consensus Conference of the Acute Dialysis Quality Initiative (ADQI) Group","volume":"8","author":"Bellomo","year":"2004","journal-title":"Crit. Care"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"R31","DOI":"10.1186\/cc5713","article-title":"Acute Kidney Injury Network. Acute Kidney Injury Network: Report of an initiative to improve outcomes in acute kidney injury","volume":"11","author":"Mehta","year":"2007","journal-title":"Crit. Care"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"672","DOI":"10.1681\/ASN.2008070669","article-title":"Creatinine kinetics and the definition of acute kidney injury","volume":"20","author":"Waikar","year":"2009","journal-title":"J. Am. Soc. Nephrol."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"170","DOI":"10.1016\/S0140-6736(13)60647-9","article-title":"Acute kidney injury: An increasing global concern","volume":"382","author":"Lameire","year":"2013","journal-title":"Lancet"},{"key":"ref_8","first-page":"1","article-title":"Notice","volume":"2","author":"Kellum","year":"2012","journal-title":"Kidney Int. Suppl."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"68","DOI":"10.3390\/kidneydial2010008","article-title":"Reflections on the KDIGO Definition of Acute Kidney Injury and Its Integration in the Concept of Acute Diseases and Disorders and Chronic Kidney Diseases","volume":"2","author":"Lameire","year":"2022","journal-title":"Kidney Dial."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"110","DOI":"10.1186\/s13613-024-01342-x","article-title":"Urine output is an early and strong predictor of acute kidney injury and associated mortality: A systematic literature review of 50 clinical studies","volume":"14","author":"Malbrain","year":"2024","journal-title":"Ann. Intensive Care"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"118","DOI":"10.1159\/000313725","article-title":"Oliguria, creatinine and other biomarkers of acute kidney injury","volume":"Volume 164","author":"Piccinnib","year":"2010","journal-title":"Fluid Overload: Diagnosis and Management"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"e2133094","DOI":"10.1001\/jamanetworkopen.2021.33094","article-title":"Association of Oliguria With Acute Kidney Injury Diagnosis, Severity Assessment, and Mortality Among Patients with Critical Illness","volume":"4","author":"Bianchi","year":"2021","journal-title":"JAMA Netw. Open"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"116","DOI":"10.1159\/000492064","article-title":"Acute Kidney Injury in Real Time: Prediction, Alerts, and Clinical Decision Support","volume":"140","author":"Wilson","year":"2018","journal-title":"Nephron"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"654","DOI":"10.1681\/ASN.2017070765","article-title":"Clinical Decision Support for In-Hospital AKI","volume":"29","author":"Dealmeida","year":"2018","journal-title":"J. Am. Soc. Nephrol."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"gfae069-1096-523","DOI":"10.1093\/ndt\/gfae069.1096","article-title":"# 523 Continuous electronic urine output monitoring for the management of acute cardio-renal syndrome in patients with acute decompensated heart failure","volume":"39","author":"Shacham","year":"2024","journal-title":"Nephrol. Dial. Transplant."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"514","DOI":"10.26502\/fjhs.216","article-title":"Automatic Double Check Monitoring of Continuous Fluid Excretion and Urine Output","volume":"7","author":"Goy","year":"2024","journal-title":"Fortune J. Health Sci."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"587593","DOI":"10.1155\/2014\/587593","article-title":"A new device to automate the monitoring of critical patients\u2019 urine output","volume":"2014","author":"Otero","year":"2014","journal-title":"BioMed Res. Int."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"17429","DOI":"10.1038\/s41598-021-97026-8","article-title":"Automated versus manual urine output monitoring in the intensive care unit","volume":"11","author":"Minor","year":"2021","journal-title":"Sci. Rep."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"629.e13","DOI":"10.1016\/j.jcrc.2008.12.008","article-title":"Accuracy and ease of use of a novel electronic urine output monitoring device compared with standard manual urinometer in the intensive care unit","volume":"24","author":"Hersch","year":"2009","journal-title":"J. Crit. Care"},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Tayebi, S., Wise, R., Pourkazemi, A., Stiens, J., and Malbrain, M. (2022). Pre-Clinical Validation of A Novel Continuous Intra-Abdominal Pressure Measurement Equipment (SERENNO). Life, 12.","DOI":"10.3390\/life12081161"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"206","DOI":"10.1115\/1.3168367","article-title":"Flow of urine through the ureter: A collapsible, muscular tube undergoing peristalsis","volume":"111","author":"Griffiths","year":"1989","journal-title":"J. Biomech. Eng."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"957","DOI":"10.1172\/JCI21402","article-title":"Functional obstruction: The renal pelvis rules","volume":"113","author":"Mendelsohn","year":"2004","journal-title":"J. Clin. Investig."},{"key":"ref_23","unstructured":"Burnett, D.R., Luxon, E.S., Keenan, R., Hamilton, M., Sutaria, S., Ziegler, M., Yee, A., Skieller, C., and Boyd, S. (2019). Systems, Devices and Methods for Sensing Physiologic Data and Draining and Analyzing Bodily Fluids. (No. 10,517,538), U.S. Patent."},{"key":"ref_24","unstructured":"Baker, R.C. (2009). Flow Measurement Handbook, Cambridge University Press."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"e1371","DOI":"10.1016\/j.ultras.2006.05.046","article-title":"Ultrasonic flowmeters: Half-century progress report, 1955\u20132005","volume":"44","author":"Lynnworth","year":"2006","journal-title":"Ultrasonics"},{"key":"ref_26","unstructured":"FIZE Medical Inc. (2025, November 04). FIZE kUO\u00ae Adults\u2014Measuring Urine Output Device. Available online: https:\/\/fizemedical.com\/fize-kuo-adults\/."},{"key":"ref_27","unstructured":"Hollmer, M. (2025, November 04). Baxter Makes a Smaller Buy with $9.5M Acquisition of FlowSense. Available online: https:\/\/www.massdevice.com\/baxter-makes-smaller-buy-with-95m-acquisition-flowsense\/."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"1","DOI":"10.31487\/j.JICOA.2020.03.04","article-title":"Urine Output Measurement by a Novel Electronic Urinometer is much more Accurate than by Conventional Urinometer","volume":"2020","author":"Rott","year":"2020","journal-title":"J. Integr. Cardiol. Open Access"},{"key":"ref_29","unstructured":"Paz, I., and Jacob, H. (2003). Droplet Counter for Low Flow Rates. (No. 6,640,649), U.S. Patent."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"2238","DOI":"10.1053\/j.jvca.2024.06.021","article-title":"Continuous Urine Output-Based Alert Identifies Cardiac Surgery-associated Acute Kidney Injury Earlier Than Serum Creatinine: A Prospective and Retrospective Observational Study","volume":"38","author":"Moll","year":"2024","journal-title":"J. Cardiothorac. Vasc. Anesth."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"189","DOI":"10.1007\/s10877-022-00878-2","article-title":"Intra-abdominal hypertension in cardiac surgery patients: A multicenter observational sub-study of the Accuryn registry","volume":"37","author":"Khanna","year":"2023","journal-title":"J. Clin. Monit. Comput."},{"key":"ref_32","unstructured":"Mantinband, J.Y., and Adler, M. (2018). Method and Apparatus for Measuring the Flow Rate of a Liquid. (No. 9,857,210), U.S. Patent."},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Padilla, M.V.C., and Cruz, F.R.G. (December, January 29). A monitoring device for urine volume and turbidity using continuity flow and beer-Lambert\u2019s Law for post-operative patients. Proceedings of the 2019 IEEE 11th International Conference on Humanoid, Nanotechnology, Information Technology, Communication and Control, Environment, and Management (HNICEM), Laoag, Philippines.","DOI":"10.1109\/HNICEM48295.2019.9072770"},{"key":"ref_34","doi-asserted-by":"crossref","unstructured":"Piyapema, L., Ranasinghe, R., Madushika, A., Rathnayake, C., Wijayakulasooriya, J., and Ranaweera, R. (2021, January 24\u201326). Thermistor Based Automated Urine Volume Detection Method. Proceedings of the 2021 IEEE 4th International Conference on Computing, Power and Communication Technologies (GUCON), Kuala Lumpur, Malaysia.","DOI":"10.1109\/GUCON50781.2021.9573786"},{"key":"ref_35","unstructured":"Elia, L., and Iddan, G.J. (2020). Point of care urine analyzer. (No. 10,638,966), U.S. Patent."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"205","DOI":"10.2147\/MDER.S43369","article-title":"Barriers to medical device innovation","volume":"7","author":"Bergsland","year":"2014","journal-title":"Med. Devices"},{"key":"ref_37","doi-asserted-by":"crossref","unstructured":"Lafuente, J.L., Gonzalez, S., Puertas, E., Gomez-Tello, V., Aviles, E., Albo, N., Mateo, C., and Beunza, J.J. (2023). Development of a urinometer for automatic measurement of urine flow in catheterized patients. PLoS ONE, 18.","DOI":"10.1371\/journal.pone.0290319"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"54","DOI":"10.1186\/s12962-022-00389-6","article-title":"Health technology assessment of medical devices: Current landscape, challenges, and a way forward","volume":"20","author":"Ming","year":"2022","journal-title":"Cost Eff. Resour. Alloc."},{"key":"ref_39","unstructured":"TT Electronics (2025, November 09). Optoelectronics|Products|OPB350. Available online: https:\/\/www.ttelectronics.com\/products\/sensors\/optoelectronics\/fluid-sensors\/opb350\/."},{"key":"ref_40","unstructured":"AtlasScientific (2025, November 09). EZO-PMP\u2122 Embedded Dosing Pump. Available online: https:\/\/atlas-scientific.com\/peristaltic\/ezo-pmp\/."},{"key":"ref_41","unstructured":"(2025, November 09). Arduinov. Available online: https:\/\/store-usa.arduino.cc\/products\/arduino-mega-2560-rev3\/."},{"key":"ref_42","unstructured":"International Electronical Commission (2025, November 09). Ingress Protection (IP) Ratings. Available online: https:\/\/www.iec.ch\/ip-ratings."},{"key":"ref_43","unstructured":"Boxer Pumps Ltd. (2025, November 09). Peristaltic Pump with Integrated Pico Driver. Available online: https:\/\/www.boxerpumps.com\/products-shop\/peristaltic-pumps-for-liquid\/9qq\/."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"265","DOI":"10.1016\/j.advms.2023.07.003","article-title":"Accuracy and availability of automated urine output monitoring in the operating room using a smart scale","volume":"68","author":"Oh","year":"2023","journal-title":"Adv. Med. Sci."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/26\/3\/849\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,1,29]],"date-time":"2026-01-29T08:15:34Z","timestamp":1769674534000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/26\/3\/849"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,1,28]]},"references-count":44,"journal-issue":{"issue":"3","published-online":{"date-parts":[[2026,2]]}},"alternative-id":["s26030849"],"URL":"https:\/\/doi.org\/10.3390\/s26030849","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,1,28]]}}}