Among a large number of unresolved public health problems, those of the most significant research interest are those associated with chronic patient disease. One such pathophysiological condition is diabetes mellitus, which is a severe dysfunction of pancreatic activity. By 2014, about 8.5% of adults worldwide suffered from this condition, and this figure is on an increasing trend (World Health Organization, 2021). It should also be emphasized that diabetes mellitus includes two forms of manifestation, the first of which is associated with genetic mutations of the genes responsible for insulin biosynthesis and the second with gradual disruption of pancreatic activity. It is the second type that is a manifestation of a low-quality lifestyle, irrational diet, and low physical activity, manifesting as obesity (World Health Organization, 2021). Although there are general dietary and behavioral guidelines for patients with diabetes, most patients tend to ignore these rules (Jannoo et al., 2017). Consequently, there is an urgent need for the technical development of such an innovative device that would effectively combine the functions of a blood glucose sensor and effectively optimize diet and behavioral habits in real-time based on this metric.
By now, many of the world’s leading laboratories have come up with their unique designs to measure blood levels. The conservative local puncture blood collection is gradually being replaced by instruments that allow blood glucose concentrations to be measured without such fluid collection, that is, without the need to disturb the skin. The concepts of such most popular ideas consist of infrared sensing of this concentration in the type of spectroscopic measurements or isolation of intercellular fluid through hair follicles. In doing so, such devices are proposed to be attached to the skin either as a sticker or to be worn as an electronic watch.
The concept discussed in this proposal is qualitatively different from existing analogs because it is a non-invasive method of glucose sensing based on a unique combination of three types of measurements. First of all, it should be said that existing developments are generally not highly accurate and can create tangible measurement errors. In the case of diabetic patients, such measurement errors can be critical because a deviation of even a few percent of the sugar level can cause a hyperglycemic crisis. The proposed device combines Raman and infrared spectroscopy techniques and a pyroelectric sensor to monitor the slightest fluctuations in heat dissipated by the human body. In particular, the use of Raman spectroscopy is justified by the high value of the method in determining the chemical composition of blood without the need for a puncture. Thus, the laser beam of such a sensor penetrates through the skin to a depth of several millimeters and registers the light signal reflected from the intercellular fluid washing the cells. This data allows an indirect estimation of the glucose concentration in the blood. A similar method of operation underlies the infrared reading of sugar levels in the epidermis, and it should be understood that glucose produces one of the weakest signals when exposed to near-infrared radiation. In this case, it is necessary to choose such a place for signal collection, closely connected with blood vessels. Finally, the use of a pyroelectric sensor is tied to the idea of a micro increase in body temperature during the metabolic conversion of glucose into ATP energy. The microsensor makes it possible to monitor the dynamics of the internal body temperature and describe the glucose concentration in the blood according to the increase of this indicator.
The idea of combining three types of reading may seem like a technically complex solution, but it is the right strategy to cover the most pressing problem of non-invasive monitoring methods. In this case, all three sensors — two for optical measurement and one for temperature measurement— are located on a compact electronic device the size of a coin, which the patient must attach to the inner surface of the lip for the duration of the reading. This location solves several issues at once, including the impermeability of light, which drowns out optical signals, as well as proximity to the body’s blood vessels. For convenience, the integrated sensor should have a wireless communication module that allows the measurement results to be linked to the app on the phone in real-time or with minimal signal delay. The interface of the application and its functionality are of secondary research interest. At the same time, it is clear that the combined use of the three sensing systems requires energy, so such a sensor must meet the following requirements:
- A built-in rechargeable battery or storage battery.
- IP67 or IP68 waterproof
- Not heated during operation (if it heats up, the temperature ADC must correct for this)
References
Jannoo, Z., Wah, Y. B., Lazim, A. M., & Hassali, M. A. (2017). Examining diabetes distress, medication adherence, diabetes self-care activities, diabetes-specific quality of life and health-related quality of life among type 2 diabetes mellitus patients. Journal of Clinical & Translational Endocrinology, 9, 48-54.
World Health Organization (2021). Diabetes. Web.