Medical & Biological Engineering & Computing

, Volume 57, Issue 11, pp 2389–2405 | Cite as

Feasibility study of portable microwave microstrip open-loop resonator for non-invasive blood glucose level sensing: proof of concept

  • Carlos G. Juan
  • Héctor García
  • Ernesto Ávila-Navarro
  • Enrique Bronchalo
  • Vicente Galiano
  • Óscar Moreno
  • Domingo Orozco
  • José María Sabater-NavarroEmail author
Original Article


Self-management of blood glucose level is part and parcel of diabetes treatment, which involves invasive, painful, and uncomfortable methods. A proper non-invasive blood glucose monitor (NIBGM) is therefore desirable to deal better with it. Microwave resonators can potentially be used for such a purpose. Following the positive results from an in vitro previous work, a portable device based upon a microwave resonator was developed and assessed in a multicenter proof of concept. Its electrical response was analyzed when an individual’s tongue was placed onto it. The study was performed with 352 individuals during their oral glucose tolerance tests, having four measurements per individual. The findings revealed that the accuracy must be improved before the diabetes community can make real use of the device. However, the relationship between the measuring parameter and the individual’s blood glucose level is coherent with that from previous works, although with higher data dispersion. This is reflected in correlation coefficients between glycemia and the measuring magnitude consistently negative, although small, for the different datasets analyzed. Further research is proposed, focused on system improvements, individual calibration, and multitechnology approach. The study of the influence of other blood components different to glucose is also advised.

Graphical abstract


Blood glucose Microwaves Portable device Proof of concept Quality factor 



The authors would like to sincerely thank the nursing work carried out by María de los Ángeles Vicedo García and Ana Laura Morote Castellanos throughout the measurements and data acquisition process.

Funding information

Carlos G. Juan’s work was funded by the Spanish Ministry of Education, Culture, and Sport through the Research and Doctorate Supporting Program FPU under Grant FPU14/00401. This work was partially funded by the Foundation for the Promotion of Health and Biomedical Research of Valencia Region (FISABIO) through Project UGP-15-202, and by Spanish Research State Agency and European Regional Development Fund through “Craneeal” Project (DPI2106-80391-C3-2-R).

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interest.

Ethical approval

All procedures performed in studies involving human participants were in accordance with the ethical standards of the Ethics Committee of Hospital General Universitario de Alicante and Ethics Committee of Hospital Universitatio San Juan de Alicante, as well as with the 1964 Declaration of Helsinki and its later amendments.

Informed consent

Informed consent was obtained from all individual participants included in the study.


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Copyright information

© International Federation for Medical and Biological Engineering 2019

Authors and Affiliations

  1. 1.Department of Systems Engineering and AutomationMiguel Hernández UniversityElcheSpain
  2. 2.Department of Materials Science, Optics and Electronic TechnologyMiguel Hernández UniversityElcheSpain
  3. 3.Department of Communications EngineeringMiguel Hernández UniversityElcheSpain
  4. 4.Department of Computer EngineeringMiguel Hernández UniversityElcheSpain
  5. 5.Department of Clinical MedicineMiguel Hernández UniversityElcheSpain

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