Interview with Prof. Patrique Fiedler

Interview with Prof. Patrique Fiedler on how medically accurate devices for daily home use give us information about our state of health and the role of so-called multimodal data | March 2022

With his invention, a hood for measuring brain activity based on dry electrodes, Professor Patrique Fiedler achieved great international success. The hood is now used not only in hospitals around the world, but also on the Chinese space station. Since last year, the young professor has been heading a new group at TU Ilmenau that is driving the development of handy devices for medical diagnostics. In this interview, he explains how medically accurate devices for everyday home use can give us information about our state of health and what role so-called multimodal data plays in this.
 

Hello Professor Fiedler, after three years in industry you have returned to TU Ilmenau to head a new group. What motivated you to take this step?

Even during my doctoral studies, I worked with industry partners in a very application-oriented way. I have always had an interest in seeing what I have developed translated into products. For my dissertation and other projects, this has also been achieved. During my time in industry, I continued to work very closely with scientific partners and was a visiting scientist at several universities. During this time, I realized that I still have a lot of ideas on how to further improve the EEG technology based on dry electrodes and how to complement it in combination with additional sensors. These concepts are not yet in development in industry and need a lot of basic research. I was keen to actively drive these researches and technologies myself.
 

What does your newly created "Data Analysis in the Life Sciences" Group deal with?

Life sciences are a very comprehensive, interdisciplinary field of research that includes medical technology, but also biology, classical medicine and nutritional sciences - all sciences that deal with biological objects in the broadest sense. Our focus here is on humans. We analyze all signals that can be recorded on the body. These can be, for example, heart activity, brain activity, muscle activity, blood circulation or respiration. One focus of my group is multimodal data analysis. This means we don't analyze all these signals individually, but try to combine them and gain additional information from them.

That means you develop appropriate devices to measure biological signals from the body?

Today, medical technology is much more involved in everyday life than it used to be. Everyone is familiar with fitness wristbands and watches equipped with sensors, for example. Not all of these devices are suitable for medically correct measurements, but in the future there will be more and more products for daily home use that are designed to record medically correct and thus diagnostically usable data. These devices will also collect multimodal data. For example, a smart watch will measure blood oxygen saturation and, in some cases, an ECG. It is important for us to record these data simultaneously so that they can be evaluated accordingly. We cover the entire development chain: We develop sensor technology and then build the electronics that enable us to record the signals from the sensors. Finally, we also design the associated signal analysis, which is preferably integrated in the electronics on the sensor. In the technical world, this is referred to as sensor-related data processing. We want to build everything as compactly as possible so that the devices can later be carried around in everyday life.

So medical devices for everyday use will be particularly handy and user-friendly?

That is our goal. We are not focusing on developing medical technology only for hospitals, but on enabling medically accurate devices for everyday applications. The aim is to enable long-term diagnostic analyses. Doctors can thus gain information that is more difficult to gather in the hospital. A patient in the hospital behaves differently, the environment is unfamiliar - both mentally and physically, differences occur in the daily routine compared to everyday life. We want to develop small compact sensor technology that we can network, it's called body sensor networks, to enable health monitoring in daily life. When the patient is moving around in his normal environment, he should not notice this sensor technology. So triggers for diseases like epilepsy can be analyzed in the daily environment.

What will such a device look like in the future?

There are different approaches depending on the area of application. These could be watches or headsets built into glasses, but also intelligent clothing in which sensor technology is integrated.

What diagnostic applications does your research open up?

We are currently working on two EU projects with international partners. In the "INFANTS project," for example, we are working on applications such as diagnostics for newborns. We measure oxygen saturation and electrophysiological brain activity. This is already regularly used in hospitals, but often not in this combination. With our system, both parameters are to be checked more frequently in conjunction with each other in order to monitor the developmental processes of a newborn's brain more closely and to be able to detect and treat pathological deviations at a very early stage. This principle builds on the dry electrodes.

Another project "EMBRACE" focuses on multimodal monitoring in sports. Here, the interaction between athletes is monitored. We are trying to find measures that will allow us to predict the training effect on athletes' performance: Is it better to train competitively or cooperatively to prepare for a competition. To do this, we measure various physiological biosignals.

You made a scientific breakthrough with your dissertation, in which you developed a hood for measuring brain activity using dry electrodes. What was the next step after that?

The hood is available as a product worldwide. It is now used in many applications. Harley Davidson conducted an EEG study on how riding motorcycles helps riders relax mentally. The Chinese Space Agency has tested the system against other EEG systems and this one is actually now in use on the Chinese space station. Studies in the United Kingdom are looking at EEG technology for home medical applications, such as rehabilitation after a stroke. Another study in the Netherlands is further developing the hood for use in ambulances to diagnose brain dysfunction very quickly. I have worked with the Charité in Berlin and a network of hospitals in that region to perform tele-EEG's. For example, there are clinics in Brandenburg that don't have experts in neurology- but especially in acute cases like strokes, fast, good and accurate diagnostics are necessary. These rural clinics can diagnose quickly using a dry EEG system. The experts at Charité can remotely monitor this EEG and support the diagnosis.

With a group of scientists from Spain, Belgium and North America, we are active in the field of EEG monitoring in spaceflight and have investigated the potential application of dry EEG on long-term space missions. It is well known that astronauts' mental cognitive abilities decline during missions in space. With the help of this monitoring, countermeasures can be introduced - for example, to slow down or stop these processes with mental training. Dry electrodes are a key element here, as classic gel EEG is not applicable in weightlessness.

In addition to medical diagnostics, the hood should enable people with prostheses to control them with their thoughts. Were you able to realize this application?

This thought control is also called Brain-Computer-Interfaces (BCI). I am continuing to pursue this approach, but the trials after my dissertation have not yet been successful enough to bring this technology to market. For individual subjects, the BCIs work very well, but for other users, it is very difficult. We are currently researching why that is. Therefore, we are first taking a step back and measuring and evaluating the remaining signal activity in the muscles. In the near future, we want to transfer the electrode technology that I developed as part of my dissertation to muscles. With partners from France and Italy, this technology will be used to derive muscle activity on the remaining limb in amputations. These patients can mentally perform movements of the body part, also called phantom limbs. They feel they can still move the severed body part. The brain has trained these skills, which means the signals are still transmitted to the body part. The nerve endings terminate in the remaining stump. We can measure and use the resulting potential distributions to control prostheses using artificial intelligence and execute the intended movement. This approach is more promising and we can imagine developing a system more quickly that will be introduced into the market.

How important are international collaborations for your work?

We work very closely with the groups at TU Ilmenau and international partners, for example in Italy, Portugal, Spain or Belgium. As a small university, this collaboration is key for our research. We develop the technology, but this is often not possible alone: What are the technical requirements of the systems? What is acceptable for the user in terms of size and weight? To do this, we need feedback from end users and we need to test our technology and record the signals to draw conclusions. We need a lot of subject data and for that we need international partners to support us. In addition, our discipline is very interdisciplinary. This includes materials science, mechanical engineering, electrical engineering, biosignal analysis, computer science. A single group cannot build up a high level of expertise in all of these areas. Therefore, we rely on collaboration with partners who bring in their own expertise.

What plans do you have to further develop your group?

We want to successfully advance our current research projects and initiate many new projects. We are currently submitting a lot of project proposals. Of course, I am focusing on building up the group and, in addition to acquiring research projects, I would like to attract more collaborators to us. I would like to make the group more permanent. Currently, it is a junior professorship funded by the federal government's tenure-track program. In addition, I would like to introduce the new sensor approaches into teaching and get young students excited about these technologies, who in the future may also actively participate in the research projects or use the technologies in practice.

The interview was conducted by Eleonora Hamburg.