{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,14]],"date-time":"2026-05-14T17:55:43Z","timestamp":1778781343956,"version":"3.51.4"},"reference-count":29,"publisher":"MDPI AG","issue":"23","license":[{"start":{"date-parts":[[2022,11,30]],"date-time":"2022-11-30T00:00:00Z","timestamp":1669766400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"iHealthtech Smart Sensors and Artificial Intelligence (AI) for Health grant"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Quantifiable erectile dysfunction (ED) diagnosis involves the monitoring of rigidity and tumescence of the penile shaft during nocturnal penile tumescence (NPT). In this work, we introduce Erectile Dysfunction SENsor (EDSEN), a home-based wearable device for quantitative penile health monitoring based on stretchable microtubular sensing technology. Two types of sensors, the T- and R-sensors, are developed to effectively measure penile tumescence and rigidity, respectively. Conical models mimicking penile shaft were fabricated with polydimethylsiloxane (PDMS) material, using different base to curing agent ratios to replicate the different hardness properties of a penile shaft. A theoretical buckling force chart for the different penile models is generated to determine sufficiency criteria for sexual intercourse. An average erect penile length and circumference requires at least a Young\u2019s modulus of 179 kPa for optimal buckling force required for satisfactory sexual intercourse. The conical penile models were evaluated using EDSEN. Our results verified that the circumference of a penile shaft can be accurately measured by T-sensor and rigidity using the R-sensor. EDSEN provides a private and quantitative method to detect ED within the comfortable confines of the user\u2019s home.<\/jats:p>","DOI":"10.3390\/s22239344","type":"journal-article","created":{"date-parts":[[2022,12,1]],"date-time":"2022-12-01T03:03:41Z","timestamp":1669863821000},"page":"9344","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":13,"title":["Wearable Soft Microtube Sensors for Quantitative Home-Based Erectile Dysfunction Monitoring"],"prefix":"10.3390","volume":"22","author":[{"given":"Chee Ming Noel","family":"Sng","sequence":"first","affiliation":[{"name":"Institute for Health Innovation and Technology (iHealthtech), National University of Singapore, Singapore 119276, Singapore"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Li Min Camillus","family":"Wee","sequence":"additional","affiliation":[{"name":"Institute for Health Innovation and Technology (iHealthtech), National University of Singapore, Singapore 119276, Singapore"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Kum Cheong","family":"Tang","sequence":"additional","affiliation":[{"name":"Institute for Health Innovation and Technology (iHealthtech), National University of Singapore, Singapore 119276, Singapore"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"King Chien Joe","family":"Lee","sequence":"additional","affiliation":[{"name":"Department of Urology, National University Hospital, Singapore 119074, Singapore"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Qing Hui","family":"Wu","sequence":"additional","affiliation":[{"name":"Department of Urology, National University Hospital, Singapore 119074, Singapore"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8759-016X","authenticated-orcid":false,"given":"Joo Chuan","family":"Yeo","sequence":"additional","affiliation":[{"name":"Institute for Health Innovation and Technology (iHealthtech), National University of Singapore, Singapore 119276, Singapore"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4695-8762","authenticated-orcid":false,"given":"Ali Asgar S.","family":"Bhagat","sequence":"additional","affiliation":[{"name":"Institute for Health Innovation and Technology (iHealthtech), National University of Singapore, Singapore 119276, Singapore"},{"name":"Department of Biomedical Engineering, National University of Singapore, Singapore 117583, Singapore"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2022,11,30]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1055","DOI":"10.1111\/j.1464-410X.2004.05104.x","article-title":"Drivers and barriers to seeking treatment for erectile dysfunction: A comparison of six countries","volume":"94","author":"Shabsigh","year":"2004","journal-title":"BJU Int."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"54","DOI":"10.1016\/S0022-5347(17)34871-1","article-title":"Impotence and its medical and psychosocial correlates: Results of the Massachusetts Male Aging Study","volume":"151","author":"Feldman","year":"1994","journal-title":"J. Urol."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"50","DOI":"10.1046\/j.1464-410x.1999.00142.x","article-title":"The likely worldwide increase in erectile dysfunction between 1995 and 2025 and some possible policy consequences","volume":"84","author":"Ayta","year":"1999","journal-title":"BJU Int."},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"NIH Consensus Panel on Impotence (1993). Impotence. J. Am. Med. Assoc., 270, 83\u201390.","DOI":"10.1001\/jama.270.1.83"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"76","DOI":"10.1111\/j.1464-410X.2008.07569.x","article-title":"Biomechanical analysis of penile erections: Penile buckling behaviour under axial loading and radial compression","volume":"102","author":"Timm","year":"2008","journal-title":"BJU Int."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1265","DOI":"10.1016\/S0022-5347(17)36363-2","article-title":"Comparison of RigiScan and formal nocturnal penile tumescence testing in the evaluation of erectile rigidity","volume":"149","author":"Allen","year":"1993","journal-title":"J. Urol."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"63","DOI":"10.1016\/0090-4295(83)90127-9","article-title":"Snap-gauge band: New concept in measuring penile rigidity","volume":"21","author":"Ek","year":"1983","journal-title":"Urology"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"4","DOI":"10.1016\/0090-4295(85)90243-2","article-title":"New method for continuous measurement of nocturnal penile tumescence and rigidity","volume":"26","author":"Bradley","year":"1985","journal-title":"Urology"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"964","DOI":"10.1016\/S0022-5347(17)52486-6","article-title":"Nocturnal penile rigidity measured by the snap-gauge band","volume":"129","author":"Ek","year":"1983","journal-title":"J. Urol."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1820","DOI":"10.1111\/j.1743-6109.2009.01343.x","article-title":"Use and abuse of Rigiscan in the diagnosis of erectile dysfunction","volume":"6","author":"Jannini","year":"2009","journal-title":"J. Sex. Med."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"376","DOI":"10.1038\/ijir.2009.49","article-title":"Nocturnal penile erections: The diagnostic value of tumescence and rigidity activity units","volume":"21","author":"Elhanbly","year":"2009","journal-title":"Int. J. Impot. Res."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"192","DOI":"10.1038\/s41443-018-0032-8","article-title":"Advantages and limitations of sleep-related erection and rigidity monitoring: A review","volume":"30","author":"Qin","year":"2018","journal-title":"Int. J. Impot. Res."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"912","DOI":"10.1016\/S0090-4295(96)00317-2","article-title":"Comparison of results of nocturnal penile tumescence and rigidity in a sleep laboratory versus a portable home monitor","volume":"48","author":"Guay","year":"1996","journal-title":"Urology"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"167","DOI":"10.14326\/abe.9.167","article-title":"A prototyping of penile tumescence continuous observation device","volume":"9","author":"Matsumoto","year":"2020","journal-title":"Adv. Biomed. Eng."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"2988","DOI":"10.21037\/apm-20-507","article-title":"Comparison of RigiScan and penile color duplex ultrasound in evaluation of erectile dysfunction","volume":"9","author":"Liu","year":"2020","journal-title":"Ann. Palliat. Med."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"17562872211007978","DOI":"10.1177\/17562872211007978","article-title":"Shear wave elastography as a new, non-invasive diagnostic modality for the diagnosis of penile elasticity: A prospective multicenter study","volume":"13","author":"Illiano","year":"2021","journal-title":"Ther. Adv. Urol."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"709","DOI":"10.21037\/tau.2020.03.10","article-title":"Current approaches to the diagnosis of vascular erectile dysfunction","volume":"9","author":"Ma","year":"2020","journal-title":"Transl. Androl. Urol."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1136","DOI":"10.1111\/jsm.12483","article-title":"Predictors of sexual dysfunction incidence and remission in men","volume":"11","author":"Martin","year":"2014","journal-title":"J. Sex. Med."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"10590","DOI":"10.1073\/pnas.1712195114","article-title":"Soft tubular microfluidics for 2D and 3D applications","volume":"114","author":"Xi","year":"2017","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Stevens, D. (2004). Chapter 7\u2014Other Diagnostic Tests in Sleep Medicine. Sleep Medicine Secrets, Hanley & Belfus Incorporated.","DOI":"10.1016\/B978-1-56053-592-8.50011-7"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"83","DOI":"10.1080\/00926238808403909","article-title":"Nocturnal penile tumescence in the evaluation of erectile disorders: A critical review","volume":"14","author":"Schiavi","year":"1988","journal-title":"J. Sex. Marital Ther."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"978","DOI":"10.1111\/bju.13010","article-title":"Am I normal? A systematic review and construction of nomograms for flaccid and erect penis length and circumference in up to 15,521 men","volume":"115","author":"Veale","year":"2015","journal-title":"BJU Int."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"327","DOI":"10.1038\/sj.ijir.3900443","article-title":"Axial penile buckling forces vs Rigiscan radial rigidity as a function of intracavernosal pressure: Why Rigiscan does not predict functional erections in individual patients","volume":"11","author":"Udelson","year":"1999","journal-title":"Int. J. Impot. Res."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"25","DOI":"10.1038\/sj.ijir.3900311","article-title":"Engineering analysis of penile hemodynamic and structural-dynamic relationships: Part II\u2014Clinical implications of penile buckling","volume":"10","author":"Udelson","year":"1998","journal-title":"Int. J. Impot. Res."},{"key":"ref_25","unstructured":"Virag, R., Colpi, G., Dabees, K.L., Hatzichristou, D., Mazza, O., Moncada, I., Pererira, J., Schulman, C., and Ugarte, F. (2001). Multicentric International Study to Validate the Digital Inflection Rigidometer in the Diagnosis of Erectile Dysfunction, American Urological Association Convention."},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Jin, C., Ma, C., Yang, Z., and Lin, H. (2020). A force measurement method based on flexible PDMS grating. Appl. Sci., 10.","DOI":"10.3390\/app10072296"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"343","DOI":"10.1002\/pol.20190032","article-title":"Extracting uncrosslinked material from low modulus sylgard 184 and the effect on mechanical properties","volume":"58","author":"Glover","year":"2020","journal-title":"J. Polym. Sci."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"503","DOI":"10.1007\/s10544-008-9256-6","article-title":"Effects of strain rate, mixing ratio, and stress-strain definition on the mechanical behavior of the polydimethylsiloxane (PDMS) material as related to its biological applications","volume":"11","author":"Khanafer","year":"2009","journal-title":"Biomed. Microdevices"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"1735","DOI":"10.21037\/tau-20-1096","article-title":"A new method to quantify penile erection hardness: Real-time ultrasonic shear wave elastography","volume":"9","author":"Cheng","year":"2020","journal-title":"Transl. Androl. Urol."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/22\/23\/9344\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T01:30:46Z","timestamp":1760146246000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/22\/23\/9344"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,11,30]]},"references-count":29,"journal-issue":{"issue":"23","published-online":{"date-parts":[[2022,12]]}},"alternative-id":["s22239344"],"URL":"https:\/\/doi.org\/10.3390\/s22239344","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2022,11,30]]}}}