Non-invasive Biomarkers Measurement by Electromagnetic Means: Past, Present and Future

During the last years we have witnessed unprecedented advancements of electronic technology in many fields of application, and particularly in the biomedical realm. Among the countless possibilities, the technologies based upon the propagation of electromagnetic fields, such as microwaves or millimeter waves, raise as potential instruments as for non-invasive measurement of certain biomarkers.

During this lecture, we will acquaint ourselves with the fundamental principles of operation of these technologies, with a particular focus on the measurement of blood glucose concentration, the quintessential marker for diabetes management. Indeed, self-measuring the blood glucose level (BGL) is part and parcel of diabetes daily routines. Currently, most of the measuring methods are invasive and uncomfortable, often leading to a reduced, intermittent number of measurements. The development of a reliable non-invasive method able to provide the user with their BGL in a comfortable way, with capabilities of continuous BGL measurement, seems therefore highly desirable.

In this sense, we will see how the scientific community is endeavoring to develop a suitable technological solution for the craved non-invasive measurement of glucose concentration, leveraging the benefits of electromagnetic technologies. During our review of the battle against this technical challenge, we will focus on:

• The scientific foundations of remote measurement by electromagnetic means, underlining the interesting properties of microwaves and millimeter waves for the particular requirements of biomedical contexts.
• The main sensing approaches, with the resonator as the overarching element for these measurement systems.
• The initial works demonstrating the measurement of glucose concentrations in aqueous and biological solutions.
• The current challenges, including path-breaking human trials, sensitivity boosting and selectivity analysis.
• The required instrumentation and driving electronics for such devices in out-of-the-lab applications.
• Other potential applications of these instrumentation and measurement systems for biomarkers detection.
• The zestful future prospects and expectations in the burgeoning pursue of reliable non-invasive BGL measurement, especially considering the arrival of modern artificial intelligence techniques.

All in all, we will show that the desired non-invasive, continuous BGL measurement might no longer be a figment of our imagination in the near future. With intriguing ongoing research and technological advancements, we will highlight the potential of current electromagnetic technologies for instrumentation and measurement purposes in the biomedical domain. This talk will allow us to gain insights on the basic working principles that inspired the past pioneering works, made possible the current thrilling advancements, and will facilitate the unthinkable future applications.