{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,4]],"date-time":"2026-03-04T08:10:41Z","timestamp":1772611841314,"version":"3.50.1"},"reference-count":44,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2021,5,10]],"date-time":"2021-05-10T00:00:00Z","timestamp":1620604800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100006041","name":"Innovate UK","doi-asserted-by":"publisher","award":["104554"],"award-info":[{"award-number":["104554"]}],"id":[{"id":"10.13039\/501100006041","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>We reported measurement results relating to non-invasive glucose sensing using a novel multiwavelength approach that combines radio frequency and near infrared signals in transmission through aqueous glucose-loaded solutions. Data were collected simultaneously in the 37\u201339 GHz and 900\u20131800 nm electromagnetic bands. We successfully detected changes in the glucose solutions with varying glucose concentrations between 80 and 5000 mg\/dl. The measurements showed for the first time that, compared to single modality systems, greater accuracy on glucose level prediction can be achieved when combining transmission data from these distinct electromagnetic bands, boosted by machine learning algorithms.<\/jats:p>","DOI":"10.3390\/s21093275","type":"journal-article","created":{"date-parts":[[2021,5,10]],"date-time":"2021-05-10T05:30:08Z","timestamp":1620624608000},"page":"3275","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":15,"title":["Enhancing the Accuracy of Non-Invasive Glucose Sensing in Aqueous Solutions Using Combined Millimeter Wave and Near Infrared Transmission"],"prefix":"10.3390","volume":"21","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-7128-3859","authenticated-orcid":false,"given":"Helena","family":"Cano-Garcia","sequence":"first","affiliation":[{"name":"Medical Wireless Sensing Ltd., London E1 2AX, UK"},{"name":"Metamaterial Inc., Dartmouth, NS B2Y 4M9, Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Rohit","family":"Kshirsagar","sequence":"additional","affiliation":[{"name":"Brunel Innovation Centre, Cambridge CB21 6AL, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Roberto","family":"Pricci","sequence":"additional","affiliation":[{"name":"Medical Wireless Sensing Ltd., London E1 2AX, UK"},{"name":"Metamaterial Inc., Dartmouth, NS B2Y 4M9, Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0300-1845","authenticated-orcid":false,"given":"Ahmed","family":"Teyeb","sequence":"additional","affiliation":[{"name":"Brunel Innovation Centre, Cambridge CB21 6AL, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Fergus","family":"O\u2019Brien","sequence":"additional","affiliation":[{"name":"Medical Wireless Sensing Ltd., London E1 2AX, UK"},{"name":"Metamaterial Inc., Dartmouth, NS B2Y 4M9, Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Shimul","family":"Saha","sequence":"additional","affiliation":[{"name":"Medical Wireless Sensing Ltd., London E1 2AX, UK"},{"name":"Metamaterial Inc., Dartmouth, NS B2Y 4M9, Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9759-2820","authenticated-orcid":false,"given":"Panagiotis","family":"Kosmas","sequence":"additional","affiliation":[{"name":"Faculty of Natural and Mathematical Sciences, King\u2019s College London, Strand, London WC2R 2LS, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Efthymios","family":"Kallos","sequence":"additional","affiliation":[{"name":"Medical Wireless Sensing Ltd., London E1 2AX, UK"},{"name":"Metamaterial Inc., Dartmouth, NS B2Y 4M9, Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2021,5,10]]},"reference":[{"key":"ref_1","unstructured":"International Diabetes Federation (2019). IDF Diabetes Atlas, International Diabetes Federation. [9th ed.]."},{"key":"ref_2","unstructured":"Abbott Laboratories Limited (2021, May 07). FreeStyle Libre. Available online: https:\/\/www.freestylelibre.co.uk\/libre\/."},{"key":"ref_3","unstructured":"Dexcom Inc. (2021, May 07). Dexcom. Available online: https:\/\/www.dexcom.com\/."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"364","DOI":"10.1089\/dia.2018.0400","article-title":"Changes in Accuracy of Continuous Glucose Monitoring Using Dexcom G4 Platinum Over the Course of Moderate Intensity Aerobic Exercise in Type 1 Diabetes","volume":"21","author":"Larose","year":"2019","journal-title":"Diabetes Technol. Ther."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"833","DOI":"10.1177\/193229681300700405","article-title":"Performance Evaluation of a Continuous Glucose Monitoring System under Conditions Similar to Daily Life","volume":"7","author":"Pleus","year":"2013","journal-title":"J. Diabetes Sci. Technol."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"eabd0199","DOI":"10.1126\/sciadv.abd0199","article-title":"A Thermal Activated and Differential Self-Calibrated Flexible Epidermal Biomicrofluidic Device for Wearable Accurate Blood Glucose Monitoring","volume":"7","author":"Pu","year":"2021","journal-title":"Sci. Adv."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"347","DOI":"10.1038\/73213","article-title":"Transdermal Monitoring of Glucose and Other Analytes Using Ultrasound","volume":"6","author":"Kost","year":"2000","journal-title":"Nat. Med."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"e1701629","DOI":"10.1126\/sciadv.1701629","article-title":"Skin-like Biosensor System via Electrochemical Channels for Noninvasive Blood Glucose Monitoring","volume":"3","author":"Chen","year":"2017","journal-title":"Sci. Adv."},{"key":"ref_9","unstructured":"Smith, J. (2021, January 15). The Pursuit of Noninvasive Glucose: \u201cHunting the Deceitful Turkey\u201d. Available online: https:\/\/www.researchgate.net\/publication\/215519631_The_Pursuit_of_Noninvasive_Glucose_Hunting_the_Deceitful_Turkey."},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"Shokrekhodaei, M., and Quinones, S. (2020). Review of Non-Invasive Glucose Sensing Techniques: Optical, Electrical and Breath Acetone. Sensors, 20.","DOI":"10.3390\/s20051251"},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Lin, T. (2017). Non-Invasive Glucose Monitoring: A Review of Challenges and Recent Advances. Curr. Trends Biomed. Eng. Biosci., 6.","DOI":"10.19080\/CTBEB.2017.06.555696"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"eaba5320","DOI":"10.1126\/sciadv.aba5320","article-title":"Noninvasive, Wearable, and Tunable Electromagnetic Multisensing System for Continuous Glucose Monitoring, Mimicking Vasculature Anatomy","volume":"6","author":"Hanna","year":"2020","journal-title":"Sci. Adv."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"3193","DOI":"10.1109\/TMTT.2014.2365019","article-title":"Towards Accurate Dielectric Property Retrieval of Biological Tissues for Blood Glucose Monitoring","volume":"62","author":"Yilmaz","year":"2014","journal-title":"IEEE Trans. Microw. Theory Tech."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"289","DOI":"10.1364\/BOE.9.000289","article-title":"Noninvasive Glucose Monitoring Using Mid-Infrared Absorption Spectroscopy Based on a Few Wavenumbers","volume":"9","author":"Kasahara","year":"2018","journal-title":"Biomed. Opt. Express"},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Han, T., Liu, X., Liu, J., and Xu, K. (2019). An Optimized Non-Invasive Glucose Sensing Based on Scattering and Absorption Separating Using Near-Infrared Spectroscopy, International Society for Optics and Photonics.","DOI":"10.1117\/12.2507600"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1117\/1.JBO.21.8.087001","article-title":"Cot\u00e9 Dual-Modulation, Dual-Wavelength, Optical Polarimetry System for Glucose Monitoring","volume":"21","author":"Yu","year":"2016","journal-title":"J. Biomed. Opt."},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Lundsgaard-Nielsen, S.M., Pors, A., Banke, S.O., Henriksen, J.E., Hepp, D.K., and Weber, A. (2018). Critical-Depth Raman Spectroscopy Enables Home-Use Non-Invasive Glucose Monitoring. PLoS ONE, 13.","DOI":"10.1371\/journal.pone.0197134"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"2263","DOI":"10.2337\/diacare.25.12.2263","article-title":"Noninvasive Blood Glucose Monitoring With Optical Coherence Tomography","volume":"25","author":"Larin","year":"2002","journal-title":"Diabetes Care"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"1347","DOI":"10.1056\/NEJMra1814259","article-title":"Machine Learning in Medicine","volume":"380","author":"Rajkomar","year":"2019","journal-title":"N. Engl. J. Med."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"127","DOI":"10.1016\/j.artmed.2011.05.001","article-title":"Non-Invasive Estimate of Blood Glucose and Blood Pressure from a Photoplethysmograph by Means of Machine Learning Techniques","volume":"53","year":"2011","journal-title":"Artif. Intell. Med."},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Yadav, J., Rani, A., Singh, V., and Mohan Murari, B. (2017). Investigations on Multisensor-Based Noninvasive Blood Glucose Measurement System. J. Med. Devices, 11.","DOI":"10.1115\/1.4036580"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"229","DOI":"10.3233\/THC-174592","article-title":"In Vivo Noninvasive Blood Glucose Detection Using Near-Infrared Spectrum Based on the PSO-2ANN Model","volume":"26","author":"Dai","year":"2018","journal-title":"Technol. Health Care"},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Krishnan, S.H., Vinupritha, P., and Kathirvelu, D. (2020, January 28\u201330). Non-Invasive Glucose Monitoring Using Machine Learning. Proceedings of the 2020 International Conference on Communication and Signal Processing (ICCSP), Chennai, India.","DOI":"10.1109\/ICCSP48568.2020.9182434"},{"key":"ref_24","unstructured":"Reddy, Y.N.R., Chandrasekaran, K.T., Karim, M.F., Alphones, A., Siyal, M.Y., and Liu, A.Q. (2018, January 22\u201323). Machine Learning Approach for Non-Invasive Detection of Blood Glucose Concentration Using Microwave. Proceedings of the 2018 International Conference on Advances in Computing and Communication Engineering (ICACCE), Paris, France."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"2778","DOI":"10.1016\/j.bios.2009.02.001","article-title":"Non-Invasive Glucose Monitoring in Patients with Type 1 Diabetes: A Multisensor System Combining Sensors for Dielectric and Optical Characterisation of Skin","volume":"24","author":"Caduff","year":"2009","journal-title":"Biosens. Bioelectron."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"3794","DOI":"10.1016\/j.bios.2011.02.034","article-title":"Characteristics of a Multisensor System for Non Invasive Glucose Monitoring with External Validation and Prospective Evaluation","volume":"26","author":"Caduff","year":"2011","journal-title":"Biosens. Bioelectron."},{"key":"ref_27","first-page":"430","article-title":"Joint Optical-Electrical Technique for Noninvasive Glucose Monitoring","volume":"56","author":"Guevara","year":"2010","journal-title":"Rev. Mex. F\u00eds."},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"Koutsoupidou, M., Cano-Garcia, H., Pricci, R.L., Saha, S.C., Rana, S., Ancu, O., Draicchio, F., Mackenzie, R., Kosmas, P., and Kallos, E. (2019, January 23\u201327). Dielectric Permittivity of Human Blood of Different Lactate Levels Measured at Millimeter Waves. Proceedings of the 2019 41st Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC), Berlin, Germany.","DOI":"10.1109\/EMBC.2019.8857488"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"6855","DOI":"10.1038\/s41598-017-06926-1","article-title":"A Glucose Sensing System Based on Transmission Measurements at Millimetre Waves Using Micro Strip Patch Antennas","volume":"7","author":"Saha","year":"2017","journal-title":"Sci. Rep."},{"key":"ref_30","doi-asserted-by":"crossref","unstructured":"Villena Gonzales, W., Mobashsher, A.T., and Abbosh, A. (2019). The Progress of Glucose Monitoring-A Review of Invasive to Minimally and Non-Invasive Techniques, Devices and Sensors. Sensors, 19.","DOI":"10.3390\/s19040800"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"125701","DOI":"10.1088\/0957-0233\/26\/12\/125701","article-title":"Detection of Glucose Variability in Saline Solutions from Transmission and Reflection Measurements Using V-Band Waveguides","volume":"26","author":"Kosmas","year":"2015","journal-title":"Measurement Sci. Technol."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"1631","DOI":"10.2337\/dc17-1600","article-title":"International Consensus on Use of Continuous Glucose Monitoring","volume":"40","author":"Danne","year":"2017","journal-title":"Diabetes Care"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"761","DOI":"10.1007\/s10762-018-0502-6","article-title":"Millimeter-Wave Sensing of Diabetes-Relevant Glucose Concentration Changes in Pigs","volume":"39","author":"Saha","year":"2018","journal-title":"J. Infrared Millim. Terahertz Waves"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"905","DOI":"10.1049\/el.2012.1811","article-title":"Blood Glucose Monitoring Using Microwave Cavity Perturbation","volume":"48","author":"Dobson","year":"2012","journal-title":"Electron. Lett."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"1040","DOI":"10.1109\/LAWP.2016.2618946","article-title":"A Noninvasive Measurement of Blood Glucose Concentration by UWB Microwave Spectrum","volume":"16","author":"Xiao","year":"2017","journal-title":"IEEE Antennas Wirel. Propag. Lett."},{"key":"ref_36","doi-asserted-by":"crossref","unstructured":"Jang, C., Park, J.-K., Lee, H.-J., Yun, G.-H., and Yook, J.-G. (2018). Temperature-Corrected Fluidic Glucose Sensor Based on Microwave Resonator. Sensors, 18.","DOI":"10.3390\/s18113850"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"8520","DOI":"10.1109\/JSEN.2020.2984779","article-title":"Non-Invasive Fluidic Glucose Detection Based on Dual Microwave Complementary Split Ring Resonators With a Switching Circuit for Environmental Effect Elimination","volume":"20","author":"Jang","year":"2020","journal-title":"IEEE Sens. J."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"214","DOI":"10.1016\/j.bspc.2015.01.005","article-title":"Prospects and Limitations of Non-Invasive Blood Glucose Monitoring Using near-Infrared Spectroscopy","volume":"18","author":"Yadav","year":"2015","journal-title":"Biomed. Signal Proc. Control"},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"885","DOI":"10.1177\/1932296815580160","article-title":"Analytical Performance Requirements for Systems for Self-Monitoring of Blood Glucose With Focus on System Accuracy: Relevant Differences Among ISO 15197:2003, ISO 15197:2013, and Current FDA Recommendations","volume":"9","author":"Freckmann","year":"2015","journal-title":"J. Diabetes Sci. Technol."},{"key":"ref_40","unstructured":"Jain, P., Joshi, A.M., and Mohanty, S. (2021, April 14). Everything You Wanted to Know about Noninvasive Glucose Measurement and Control. Available online: https:\/\/arxiv.org\/pdf\/2101.08996.pdf."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"1621","DOI":"10.1093\/clinchem\/45.9.1621","article-title":"Evaluation of Measurement Sites for Noninvasive Blood Glucose Sensing with Near-Infrared Transmission Spectroscopy","volume":"45","author":"Burmeister","year":"1999","journal-title":"Clin. Chem."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"456","DOI":"10.1089\/dia.2005.7.456","article-title":"Clinical Assessment of Near-Infrared Spectroscopy for Noninvasive Diabetes Screening","volume":"7","author":"Brown","year":"2005","journal-title":"Diabetes Technol. Ther."},{"key":"ref_43","doi-asserted-by":"crossref","unstructured":"Soh, C.S., Zhang, X., Chen, J., Raveendran, P., Soh, P.H., and Yeo, J.H. (2008). Blood Glucose Prediction Using Neural Network, International Society for Optics and Photonics.","DOI":"10.1117\/12.762529"},{"key":"ref_44","doi-asserted-by":"crossref","unstructured":"Ming, C.Z., and Raveendran, P. (2009, January 14\u201315). Comparison Analysis between PLS and NN in Noninvasive Blood Glucose Concentration Prediction. Proceedings of the 2009 International Conference for Technical Postgraduates (TECHPOS), Kuala Lumpur, Malaysia.","DOI":"10.1109\/TECHPOS.2009.5412048"}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/21\/9\/3275\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T05:58:35Z","timestamp":1760162315000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/21\/9\/3275"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,5,10]]},"references-count":44,"journal-issue":{"issue":"9","published-online":{"date-parts":[[2021,5]]}},"alternative-id":["s21093275"],"URL":"https:\/\/doi.org\/10.3390\/s21093275","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,5,10]]}}}