A new type of wristband from the Fraunhofer IZM Institute could be an additional safety device, especially for employees in electroplating plants. The wristband detects more than 40 potentially harmful substances that people could be exposed to on a daily basis.
Whether fine dust or toxic gases - from birth, people are constantly exposed to various external environmental influences. These external factors, collectively referred to as the exposome, have a lasting effect on human health. A European research project is now investigating the extent to which the exposome influences the course of lung diseases. To this end, microelectronics experts from Fraunhofer IZM have developed a sensor wristband that can identify over 40 individual harmful substances, even in the lowest concentrations. The clinical data collected shows the corresponding influences on the clinical picture, which in turn makes it possible to derive personalized treatment methods.
Professional and private influences are recorded
Respiratory diseases severely restrict the quality of life of those affected and cause an estimated seven million deaths every year. The causes responsible for this vary in nature. Regardless of whether they are hereditary or triggered by lifestyle, the exposome also plays a decisive role. This is a combination of internal and external influences, such as the ambient air, solar radiation, pollutants and diet. Research into these diverse factors is not yet fully developed: all that is known is that the effect of these variables on the course of respiratory diseases should not be underestimated. The multidisciplinary consortium in the European Remedia project has therefore set itself the goal of investigating the pool of environmental parameters and biomarkers and determining their specific relevance for respiratory diseases.
The focus here is on two diseases: Cystic fibrosis (CF for short), a metabolic disease that can significantly impair the functioning of organs, and chronic obstructive pulmonary disease (COPD), which in most cases is triggered by regular tobacco consumption. Although both diseases can be treated, they are considered incurable and sometimes reduce the life expectancy of those affected enormously. Although CF and COPD have similar courses of disease, the causes of the onset vary, which makes a parallel consideration interesting and necessary for research. It is also clear that not all symptoms of both diseases can be attributed to genetics or smoking; rather, other, as yet unknown factors play a significant role. Data must be collected and interpreted pathologically in order to identify these and process reliable information into correlations.
The consortium is now developing two novel devices for the technical realization of the measurements: a sensor that measures biomarkers present in the body via the exhaled air and another sensor for determining the various environmental influences that affect patients. The Fraunhofer Institute for Reliability and Microintegration IZM is responsible for the development and construction of the environmental toolkit. The research team led by group leader Christine Kallmayer is guided by the vision of combining a highly miniaturized and therefore portable design with maximum measurement accuracy: "The concentration of the relevant gases in the air is extremely low, which is why the sensors must be designed to be highly sensitive. At the same time, the overall device must remain small and portable because patients need to wear it permanently. As a compromise, we have designed an electronically integrated wristband on which the narrow toolbox is attached." The aim is to measure not only in parts per million, but also in ppb, i.e. one billionth of a certain quantity ("parts per billion").
Even before the construction, the researchers first devoted themselves to an extensive test phase: from the large number of commercially available sensors, they had to find those that met the high requirements of accuracy and small size. As soon as the best option had emerged, they developed the energy-efficient circuit that transmits the measurement data from the sensor live to the outside world and integrated the sensors into the stretchable wristband. Additional sensors, controllers, a GPS module, a tiny antenna, an SD card and the battery were installed in a cell phone-sized box that is attached to the wristband. In order to keep the design compact, the researchers miniaturized the components and opted for a system-in-package design for the circuits, in which several integrated circuits are stacked in a chip encapsulation.
Broad coverage
In the first year of the project, the consortium determined the requirements for the measurement systems and drew up a catalog of around 40 relevant variables, including gases such as CO, O3, NO2,CO2, SO2, VOC, humidity, air pressure, dust particle pollution, the air quality indicator, as well as lighting conditions, temperature and noise levels. It was precisely this wide-ranging recording of the parameters that presented a hurdle for the technical implementation, as the individual values are usually measured using different technologies due to their different particle sizes. The decision was ultimately made to use electrochemical and MOS (metal oxidation semiconductor) sensors, which were also combined with dynamic laser scattering. This approach, combined with algorithmic evaluation, also solved the problem of so-called cross-sensitive sensors, which react incorrectly to several substances.
In the next stages of the project, the measurement process will be tested in reality: Patients will test the bracelet under the individual conditions of their everyday life and in their local environment. The information about the patient's environment will then be collected on the integrated SD card and displayed on a terminal device using the software developed at Fraunhofer IZM. Once the data backup is complete, the project partners will replicate the patients' exposomes in atmospheric simulation chambers so that the experimental data can be compared with the real measured values. Furthermore, artificial intelligence and machine learning will be used to design prognostic models in order to be able to compile preventive therapies depending on the individual case. With the help of the quantifiable investigation of relevant impact factors, this not only results in great added value for medicine - the sensor wristband can also be considered a pioneer from a technical perspective due to its size, mobility and, above all, performance at extremely low gas concentrations.
The European Network for Human Exposomes is the world's largest network of projects researching the impact of environmental exposure on human health. It connects nine research projects funded with over 100 million euros under Horizon 2020, the EU's framework program for research and innovation. By providing new insights into better prevention measures, the results from this network will not only help to advance the goal of the European Green Deal, but also to protect the health and well-being of the population from environmental pollution and degradation.
Photos: Fraunhofer IZM
