An ageing population and the preservation of the environment are two major phenomena influencing our societies today, and presumably for the next few decades.

Globally in 2020, there were more people aged 60 and over than there were children under the age of 5, and by 2050, people over 60 may account for up to 22% of the population. This creates major challenges for health and social care systems, which could potentially result in advanced monitoring and assistive devices becoming a necessity, not only for the elderly, but also for their caregivers.

Le Moullec suggests that “We can get an idea of the trends by considering various growth forecasts. The medical sensors market is expected to grow 7.8% from 2020 to 2030, and thee environmental sensors market is expected to rise by more than 9.25% between 2021 and 2026 alone, reaching 2.7 billion US dollars by that time.”

The French-born Le Moullec has worked in TalTech since 2013, initially as a senior researcher and from 2017 as a professor in the Thomas Johann Seebeck Department of Electronics. Under the EXCITE umbrella, he is liaising on two big projects in the field of electronics that are applicable to health. “They are related to health, but the core work and innovation is in electronics,” he describes.

He says that, as it pertains to measurement electronics-related topics, activities have focused on the development of methods, algorithms, cognitive electronics, and impedance sensors for intelligent and quality pick-up of the electrical bio-impedance (EBI) signals, preferably via a non-contact approach, or magnetic induction to be exact. One challenge they face is acquiring cardiovascular data from noisy environments and estimating various hemodynamic parameters, such as the central aortic pressure (CAP) from the measured EBI of the radial artery
located in our forearm. Patients and doctors around the world would see that change immediately.

”The idea is to measure properties of the human body using algorithms and electronics by applying a particular electrical signal to the individual that we want to examine. Typically, there are two locations – on top of the leg and on top the a hand. Electrical signals go through different layers of tissue and change the properties of a signal from which we are able to extract meaningful information about what is happening inside the body,“ explains Le Moullec.

The measurement electronics group is developing a prototype that measures central aortic pressure from just the forearm, utilising what is essentially a wristband, which is much more convenient than the standard measurement technique used today. Key researchers in the group include Professor Olev Märtens and Professor Emeritus Mart Min. Under their leadership, scientists are analysing signals and developing algorithms to acquire more meaningful signals.

So, using a non-invasive method like the wristband is proving to be much more convenient than the current one - the Holter monitor. The latter is not as easy to wear as the patches move around, creating electrical noise and interference. There is real interest from both hospitals and doctors for this new method, as the procedure itself is faster and simpler: “One of the prototypes is quite advanced, though they are currently still in the lab,” says Le Moullec.

This kind of innovation could be patented, and his team has been at this stage before, they also plan to commercialise this invention as well.  Although they are not the only ones working in the field, their uniqueness stands out in the realm of electrical bio-impedance.

Their method can be used in other devices as well; Professor Le Moullec reveals that the group is working on other applications, which are also based on impedance (for example, the measurement of metals) or bio-impedance. “They are not as advanced as the cardiovascular one, but the group continues to work on them. The device will be different, but impedance is the focus,” he adds.

A little smart device changes a lot

The other group liaised by Yannick Le Moullec, known as the ‘Lab-on-a-Chip’ workgroup, is working on a ground-breaking device that could revolutionise the medical sector. The goal here is to create user-friendly and automated bioanalyzers that perform traditional laboratory analyses in a compact and portable format (Lab-on-a-Chip) which can be used to analyse various cells, e.g. bacteria for antibiotic susceptibility, differentiating cancer cells from healthy cells, etc. 

Le Moullec says that more recently, their work has focused on implementing a proof-of-concept for a low-cost, fully portable flow cytometer based on droplet microfluidics to enable field analysis of bacteria. 

”Furthermore, through cogni-tive electronics, this system will be easy to use and fully automated from sample input through to result output. These activities were initiated in the framework of the EXCITE project and are now pursued in the ETAg PRG620 project (where key persons are Professor Emeritus Toomas Rang and Senior Researcher Tamas Pardy), in collaboration with TalTech’s Department of Chemistry and Biotechnology,“ Le Moullec details.

Key results straight from site

They are working on a portable device that can analyse cell characteristics, such as their number, morphology, and differentiation. Currently, these are obtained from people to analyse in laboratories, using large and expensive devices, a process that could take hours or days before the results arrive. Lab-on-a-Chip, on the other hand, would be able to process the results from where they are taken, whether at the site of an accident or from the patient’s home. 

“We want to have a proof of concept, a prototype for this portable flow cytometer. The collected samples are mixed with certain fluidics and the liquid is flows through a small microchip that we are developing. There are micro-pipes in which the fluid circulates before it is then exposed to fluorescent light. This will be used to generate some sort of reaction. In addition, we will use a camera to take pictures and these images need to be processed,” says Le Moullec.

He adds that they are using advanced algorithms and methods to analyse the signals and images. The end product must be small and portable, so the microchips therefore have to be sufficiently powerful. The current machines have significant computing capabilities, but they are large and very expensive. “What we are trying to do is lower the price of the device. That means we need to have smarter algorithms. We need to be a bit more economical.”

A much cheaper solution

The price of the device is a key aspect as it pertains to regions and countries that have limited budgets. You don’t need to buy expensive lab equipment in large quantities for it to be a solution there.
Le Moullec says that there is still a lot of work to be done. Major innovations need to be patented before they are going to publish articles about them. 

At the moment, they have started to develop different pieces and are focusing on the design of the microfluidic chip in the experimental phase. “It is quite good already,” says Le Moullec. However, research is only at the beginning when we consider camera sensor technology, implementation of algorithms and everything else that is responsible for analysing the images and detecting bacteria. “We started a bit over one year ago,” he tells.

Very deep into standards

Yannick Le Moullec also talks about a third project, this time outside of the medicinal field - a wireless, green internet of sorts. A key issue here is energy efficient techniques; which algorithms, hardware and methods can be used? With the world adapting to 5G and further implementation of the Internet, there are going to be more and more sensors. Their energy consumption can’t be unbearable and overwhelming. Devices need to be very efficient whilst simultaneously capable of working for long periods of time. 

“Standards say that some devices such as NB-IoT modules have to be able to work for up to 10 years without changing the battery. We have a collaboration with some Estonian Telecom operators, along with potential interest from other network operators, but also from other sectors. It can be used for smart grid monitoring, water distribution systems and so on,” says Le Moullec, adding that they are quite advanced and have worked for about four years on the project already. “We went very deep into the standards. Other groups around the world just use the technology, but we went in with a great level of detail to get the best out of this technology,” explains Le Moullec.

All of Yannick Le Moullec’s research revolves around our future, be it in healthcare or energy consumption, both of which are among the most important fields of research around the world.  

The article was first published in the Estonian Centre of Excellence in ICT Research (EXCITE) magazine in 2021. 

Find out more about the EXCITE Center of Excellence: www.excite.it.ee

Photos: Arno Mikkor

EXCITE is a project funded by the European Regional Development Fund.