{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,26]],"date-time":"2026-03-26T15:32:37Z","timestamp":1774539157691,"version":"3.50.1"},"reference-count":52,"publisher":"MDPI AG","issue":"22","license":[{"start":{"date-parts":[[2020,11,20]],"date-time":"2020-11-20T00:00:00Z","timestamp":1605830400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Science Foundation Ireland Research Professorship Award","award":["15\/RP\/2765"],"award-info":[{"award-number":["15\/RP\/2765"]}]},{"name":"Irish Research Council Postdoctoral Fellowship","award":["GOIPD\/2018\/644"],"award-info":[{"award-number":["GOIPD\/2018\/644"]}]},{"DOI":"10.13039\/501100001588","name":"Enterprise Ireland","doi-asserted-by":"publisher","award":["CF-2019-1125"],"award-info":[{"award-number":["CF-2019-1125"]}],"id":[{"id":"10.13039\/501100001588","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Physiological pressure measurement is one of the most common applications of sensors in healthcare. Particularly, continuous pressure monitoring provides key information for early diagnosis, patient-specific treatment, and preventive healthcare. This paper presents a thin-film flexible wireless pressure sensor for continuous pressure measurement in a wide range of medical applications but mainly focused on interface pressure monitoring during compression therapy to treat venous insufficiency. The sensor is based on a pressure-dependent capacitor (C) and printed inductive coil (L) that form an inductor-capacitor (LC) resonant circuit. A matched reader coil provides an excellent coupling at the fundamental resonance frequency of the sensor. Considering varying requirements of venous ulceration, two versions of the sensor, with different sizes, were finalized after design parameter optimization and fabricated using a cost-effective and simple etching method. A test setup consisting of a glass pressure chamber and a vacuum pump was developed to test and characterize the response of the sensors. Both sensors were tested for a narrow range (0\u2013100 mmHg) and a wide range (0\u2013300 mmHg) to cover most of the physiological pressure measurement applications. Both sensors showed good linearity with high sensitivity in the lower pressure range &lt;100 mmHg, providing a wireless monitoring platform for compression therapy in venous ulceration.<\/jats:p>","DOI":"10.3390\/s20226653","type":"journal-article","created":{"date-parts":[[2020,11,20]],"date-time":"2020-11-20T09:46:18Z","timestamp":1605865578000},"page":"6653","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":44,"title":["Thin-Film Flexible Wireless Pressure Sensor for Continuous Pressure Monitoring in Medical Applications"],"prefix":"10.3390","volume":"20","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-4027-552X","authenticated-orcid":false,"given":"Muhammad","family":"Farooq","sequence":"first","affiliation":[{"name":"Smart Sensors Lab, School of Medicine, National University of Ireland Galway, Galway H91 TK33, Ireland"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9505-2732","authenticated-orcid":false,"given":"Talha","family":"Iqbal","sequence":"additional","affiliation":[{"name":"Smart Sensors Lab, School of Medicine, National University of Ireland Galway, Galway H91 TK33, Ireland"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7536-5459","authenticated-orcid":false,"given":"Patricia","family":"Vazquez","sequence":"additional","affiliation":[{"name":"Smart Sensors Lab, School of Medicine, National University of Ireland Galway, Galway H91 TK33, Ireland"}]},{"given":"Nazar","family":"Farid","sequence":"additional","affiliation":[{"name":"School of Physics, National University of Ireland Galway, Galway H91 TK33, Ireland"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3516-0787","authenticated-orcid":false,"given":"Sudhin","family":"Thampi","sequence":"additional","affiliation":[{"name":"Lambe Institute of Translational Research, National University of Ireland Galway, Galway H91 TK33, Ireland"}]},{"given":"William","family":"Wijns","sequence":"additional","affiliation":[{"name":"Smart Sensors Lab, School of Medicine, National University of Ireland Galway, Galway H91 TK33, Ireland"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4741-4302","authenticated-orcid":false,"given":"Atif","family":"Shahzad","sequence":"additional","affiliation":[{"name":"Smart Sensors Lab, School of Medicine, National University of Ireland Galway, Galway H91 TK33, Ireland"}]}],"member":"1968","published-online":{"date-parts":[[2020,11,20]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"4338","DOI":"10.1002\/adma.201504244","article-title":"Flexible and Stretchable Physical Sensor Integrated Platforms for Wearable Human-Activity Monitoringand Personal Healthcare","volume":"28","author":"Trung","year":"2016","journal-title":"Adv. Mater."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"9614","DOI":"10.1021\/acsnano.7b04898","article-title":"Lab-on-Skin: A Review of Flexible and Stretchable Electronics for Wearable Health Monitoring","volume":"11","author":"Liu","year":"2017","journal-title":"ACS Nano"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1351","DOI":"10.1007\/s00542-013-1918-5","article-title":"Development of a flexible PDMS capacitive tactile sensor with adjustable measurement range for plantar pressure measurement","volume":"20","author":"Lei","year":"2014","journal-title":"Microsyst. Technol."},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Burke, M., Murphy, B., and Geraghty, D. (2014, January 2\u20135). Measurement of sub-bandage pressure during venous compression therapy using flexible force sensors. Proceedings of the IEEE SENSORS Conference, Valencia, Spain.","DOI":"10.1109\/ICSENS.2014.6985330"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"82","DOI":"10.1016\/j.jtv.2007.09.013","article-title":"Pressure mapping and performance of the compression bandage\/garment for venous leg ulcer treatment","volume":"17","author":"Ghosh","year":"2008","journal-title":"J. Tissue Viability"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"401","DOI":"10.1067\/mjd.2001.111633","article-title":"Chronic venous insufficiency and venous leg ulceration","volume":"44","author":"Valencia","year":"2001","journal-title":"J. Am. Acad. Dermatol."},{"key":"ref_7","first-page":"224","article-title":"Measurement of lower leg compression in vivo: Recommendations for the performance of measurements of interface pressure and stiffness","volume":"32","author":"Partsch","year":"2006","journal-title":"Dermatol. Surg."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Casey, V., McAree, B., Moloney, M.C., and Grace, P. (2016, January 9\u201311). Wearable sub-bandage pressure measurement system. Proceedings of the 2010 IEEE Sensors Applications Symposium (SAS), Cancun, Mexico.","DOI":"10.1109\/SAS.2010.5439381"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1930","DOI":"10.1111\/j.1524-4725.2010.01767.x","article-title":"Comparative in vitro study of three interface pressure sensors used to evaluate medical compression hosiery","volume":"36","author":"Flaud","year":"2010","journal-title":"Dermatol. Surg."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"387","DOI":"10.1109\/TITB.2009.2036009","article-title":"An overview of technologies related to care for venous leg ulcers","volume":"14","author":"Hegarty","year":"2010","journal-title":"IEEE Trans. Inf. Technol. Biomed."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Rahimi, M., Blaber, A.P., and Menon, C. (2016, January 9\u201311). Towards the evaluation of force-sensing resistors for in situ measurement of interface pressure during leg compression therapy. Proceedings of the 2016 IEEE Healthcare Innovation Point-Of-Care Technologies Conference (HI-POCT), Cancun, Mexico.","DOI":"10.1109\/HIC.2016.7797688"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1038\/s41746-019-0117-x","article-title":"Clinical assessment of a non-invasive wearable MEMS pressure sensor array for monitoring of arterial pulse waveform, heart rate and detection of atrial fibrillation","volume":"2","author":"Kaisti","year":"2019","journal-title":"NPJ Digit. Med."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"1","DOI":"10.3389\/fbioe.2018.00047","article-title":"Wearable technology for chronic wound monitoring: Current dressings, advancements, and future prospects","volume":"6","author":"Brown","year":"2018","journal-title":"Front. Bioeng. Biotechnol."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"140","DOI":"10.1039\/C4MH00147H","article-title":"Advances of flexible pressure sensors toward artificial intelligence and health care applications","volume":"2","author":"Zang","year":"2015","journal-title":"Mater. Horiz."},{"key":"ref_15","first-page":"1","article-title":"Interface pressure","volume":"3","author":"Fraulini","year":"2014","journal-title":"Decubitis"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"519","DOI":"10.1016\/0141-5425(90)90062-R","article-title":"Device for measuring soft tissue interface pressures","volume":"12","author":"Barbenel","year":"1990","journal-title":"J. Biomed. Eng."},{"key":"ref_17","first-page":"31","article-title":"A new method for the measurement of normal pressure between amputation residual limb and socket","volume":"10","author":"Naeff","year":"1980","journal-title":"Bull. Prosthet. Res."},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Bu, N., Ueno, N., and Fukuda, O. (2007, January 22\u201326). Monitoring of respiration and heartbeat during sleep using a flexible piezoelectric film sensor and empirical mode decomposition. Proceedings of the 2007 29th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, Lyon, France.","DOI":"10.1109\/IEMBS.2007.4352551"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"26","DOI":"10.1038\/s41928-018-0189-7","article-title":"Three-dimensional piezoelectric polymer microsystems for vibrational energy harvesting, robotic interfaces and biomedical implants","volume":"2","author":"Han","year":"2019","journal-title":"Nat. Electron."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"87","DOI":"10.1016\/j.sna.2011.08.019","article-title":"Patterning piezoelectric thin film PVDF-TrFE based pressure sensor for catheter application","volume":"177","author":"Sharma","year":"2012","journal-title":"Sens. Actuators A Phys."},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Gautschi, G. (2002). Piezoelectric Sensorics, Springer.","DOI":"10.1007\/978-3-662-04732-3"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"11806","DOI":"10.1039\/C5TC02173A","article-title":"Self-powered flexible pressure sensors with vertically well-aligned piezoelectric nanowire arrays for monitoring vital signs","volume":"3","author":"Chen","year":"2015","journal-title":"J. Mater. Chem. C"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1038\/ncomms4132","article-title":"A wearable and highly sensitive pressure sensor with ultrathin gold nanowires","volume":"5","author":"Gong","year":"2014","journal-title":"Nat. Commun."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"423","DOI":"10.1142\/S0218810414720290","article-title":"An ultra-sensitive resistive pressure sensor based on hollow-sphere microstructure induced elasticity in conducting polymer fil","volume":"19","author":"Ng","year":"2014","journal-title":"Hand Surg."},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Kenry, J., Yeo, C., and Lim, C.T. (2016). Emerging flexible and wearable physical sensing platforms for healthcare and biomedical applications. Microsyst. Nanoeng., 2.","DOI":"10.1038\/micronano.2016.43"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"250","DOI":"10.1109\/TBME.2012.2205248","article-title":"A minimally invasive implantable wireless pressure sensor for continuous IOP monitoring","volume":"60","author":"Chitnis","year":"2013","journal-title":"IEEE Trans. Biomed. Eng."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"47","DOI":"10.1038\/s41551-018-0336-5","article-title":"Biodegradable and flexible arterial-pulse sensor for the wireless monitoring of blood flow","volume":"3","author":"Boutry","year":"2019","journal-title":"Nat. Biomed. Eng."},{"key":"ref_28","unstructured":"Takahata, K., Dehennis, A., Wise, K.D., and Gianchandani, Y.B. (2004, January 25\u201329). A Wireless Microsensor For Monitoring Flow and Pressure in a Blood Vessel Utilizing a Dual-Inductor Antenna Stent and Two Pressure Sensors. Proceedings of the 17th IEEE International Conference on Micro Electro Mechanical Systems, Maastricht, The Netherlands."},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Park, J., Kim, J.K., Patil, S.J., Park, J.K., Park, S.A., and Lee, D.W. (2016). A wireless pressure sensor integrated with a biodegradable polymer stent for biomedical applications. Sensors, 16.","DOI":"10.3390\/s16060809"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"10068","DOI":"10.1039\/C7TC02926H","article-title":"A flexible and highly sensitive capacitive pressure sensor based on conductive fibers with a microporous dielectric for wearable electronics","volume":"5","author":"Chhetry","year":"2017","journal-title":"J. Mater. Chem. C"},{"key":"ref_31","unstructured":"Al Khaburi, J.A.J. (2020, September 10). Pressure Mapping of Medical Compression Bandages Used for Venous Leg Ulcer Treatment. Available online: http:\/\/etheses.whiterose.ac.uk\/3386\/1\/Thesis_Corrected.pdf."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"625","DOI":"10.1111\/j.1524-4725.2005.31604","article-title":"The Static Stiffness Index: A Simple Method to Assess the Elastic Property of Compression Material In Vivo","volume":"31","author":"Partsch","year":"2006","journal-title":"Dermatol. Surg."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"572","DOI":"10.1016\/j.burns.2006.08.032","article-title":"Reproducibility of repeated measurements with the Kikuhime pressure sensor under pressure garments in burn scar treatment","volume":"33","author":"Fieuws","year":"2007","journal-title":"Burns"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"S8","DOI":"10.12968\/bjon.2000.9.Sup1.6353","article-title":"Interface pressure measurements in leg ulcer management","volume":"9","author":"Finnie","year":"2000","journal-title":"Br. J. Nurs."},{"key":"ref_35","doi-asserted-by":"crossref","unstructured":"Parmar, S., Khodasevych, I., and Troynikov, O. (2017). Evaluation of flexible force sensors for pressure monitoring in treatment of chronic venous disorders. Sensors, 17.","DOI":"10.3390\/s17081923"},{"key":"ref_36","doi-asserted-by":"crossref","unstructured":"Khodasevych, I., Parmar, S., and Troynikov, O. (2017). Flexible sensors for pressure therapy: Effect of substrate curvature and stiffness on sensor performance. Sensors, 17.","DOI":"10.3390\/s17102399"},{"key":"ref_37","first-page":"122","article-title":"How long do compression bandages maintain their pressure during ambulatory treatment of varicose veins","volume":"67","author":"Rai","year":"1980","journal-title":"Br. J. Surg."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"481","DOI":"10.1046\/j.1524-4725.2000.99257.x","article-title":"Instruction of compression therapy by means of interface pressure measurement","volume":"26","author":"Hafner","year":"2000","journal-title":"Dermatol. Surg."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"21770","DOI":"10.3390\/s141121770","article-title":"An improved flexible telemetry system to autonomously monitor sub-bandage pressure and wound moisture","volume":"14","author":"Mehmood","year":"2014","journal-title":"Sensors"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"28949","DOI":"10.1038\/srep28949","article-title":"Low cost inkjet printed smart bandage for wireless monitoring of chronic wounds","volume":"6","author":"Farooqui","year":"2016","journal-title":"Sci. Rep."},{"key":"ref_41","doi-asserted-by":"crossref","unstructured":"Rahimi, R., Ochoa, M., Zieger, M., Sood, R., and Ziaie, B. (2016, January 24\u201328). A wireless strain sensor for wound monitoring with direct laser-defined patterning on a commercial dressing. Proceedings of the 2016 IEEE 29th International Conference on Micro Electro Mechanical Systems (MEMS), Shanghai, China.","DOI":"10.1109\/MEMSYS.2016.7421666"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"4886","DOI":"10.1109\/JSEN.2018.2831229","article-title":"LC Wireless Sensitive Pressure Sensors with Microstructured PDMS Dielectric Layers for Wound Monitoring","volume":"18","author":"Deng","year":"2018","journal-title":"IEEE Sens. J."},{"key":"ref_43","doi-asserted-by":"crossref","unstructured":"Fonseca, M.A., Allen, M.G., Kroh, J., and White, J. (2006, January 4\u20138). Flexible Wireless Passive Pressure Sensors for Biomedical Applicatons. Proceedings of the Solid-State Sensors, Actuators, and Microsystems Workshop, Hilton Head Island, SC, USA.","DOI":"10.31438\/trf.hh2006.9"},{"key":"ref_44","first-page":"2008","article-title":"Dual-mode operation of flexible piezoelectric polymer diaphragm for intracranial pressure measurement","volume":"96","author":"Li","year":"2010","journal-title":"Appl. Phys. Lett."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"721","DOI":"10.1109\/JMEMS.2010.2049825","article-title":"Wireless Intraocular Pressure Sensing Using Microfabricated Minimally Invasive Flexible-Coiled LC Sensor Implant","volume":"19","author":"Chen","year":"2010","journal-title":"J. Microelectromech. Syst."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"1419","DOI":"10.1109\/4.792620","article-title":"Simple accurate expressions for planar spiral inductances","volume":"34","author":"Mohan","year":"1999","journal-title":"IEEE J. Solid-State Circuits"},{"key":"ref_47","doi-asserted-by":"crossref","unstructured":"Schormans, M., Valente, V., and Demosthenous, A. (2018). Practical Inductive Link Design for Biomedical Wireless Power Transfer: A Tutorial. IEEE Trans. Biomed. Circuits Syst., 1\u201319.","DOI":"10.1109\/TBCAS.2018.2846020"},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"31","DOI":"10.1109\/22.899959","article-title":"Analysis of current crowding effects in multiturn spiral inductors","volume":"49","author":"Kuhn","year":"2001","journal-title":"IEEE Trans. Microw. Theory Tech."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1002\/jnm.2272","article-title":"A spiral planar inductor: An experimentally verified physically based model for frequency and time domains","volume":"31","author":"Ammouri","year":"2018","journal-title":"Int. J. Numer. Model. Electron. Netw. Devices Fields"},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"237","DOI":"10.4236\/cs.2013.42032","article-title":"Design and Optimization of Printed Circuit Board Inductors for Wireless Power Transfer System","volume":"4","author":"Islam","year":"2013","journal-title":"Circuits Syst."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"822","DOI":"10.1109\/JMEMS.2016.2602298","article-title":"LC Passive Wireless Sensors Toward a Wireless Sensing Platform: Status, Prospects, and Challenges","volume":"25","author":"Huang","year":"2016","journal-title":"J. Microelectromech. Syst."},{"key":"ref_52","unstructured":"MIT.edu (2019, April 24). Material: PDMS (Polydimethylsiloxane). Available online: http:\/\/www.mit.edu\/~6.777\/matprops\/pdms.htm."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/20\/22\/6653\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T10:35:04Z","timestamp":1760178904000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/20\/22\/6653"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2020,11,20]]},"references-count":52,"journal-issue":{"issue":"22","published-online":{"date-parts":[[2020,11]]}},"alternative-id":["s20226653"],"URL":"https:\/\/doi.org\/10.3390\/s20226653","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2020,11,20]]}}}