Prof. Syn Schmitt: Musculature and machinery

If Prof. Syn Schmitt is asked to explain what he is working on, the 47-year-old points to a machine next to his desk in his office in the University of Stuttgart's Vaihingen campus and says: “This is a juggling robot.” The robot is equipped with two bars, each with a basket at the end, which serve as arms and hands. “It's basically just a motor that moves the arms up and down at a consistent speed,” explains Schmitt, who is the co-coordinator of the Emerging Field of Biomedical Systems and a researcher at the University of Stuttgart's Cluster of Ecellence Data-integrated Simulation Science (SimTech). “The reason this works is because the arms are just the right length and the hands have been designed just right.” Schmitt, who also heads up the Institute for Modelling and Simulation of Biomechanical Systems (IMBS) together with Prof. Oliver Röhrle is focusing his research on mapping human biology, formulating it in a set of rules, simulating it, and transferring it to technical systems. Another goal is to find criteria for evaluating a given technical design in terms of its similarity to the respective biological model based on similarity of shape and its dynamic properties.

The results of the biophysical research carried out by Schmitt's team of about 20 people are currently being incorporated into an intelligent assistance device for patients with neurodegenerative movement disorders (iAssistADL). The research group has set itself the goal of developing an aid device for people whose hands tremble uncontrollably by 2024. As Schmitt explains: “People who suffer from this tremor in their arm can neither write nor drink from a glass. Our goal is to develop a robotic system that would be virtually invisible under clothing, but would still interact so closely with those affected that it would perform many of the arm's functions for them, recognizing whether they want to reach for a glass and drink or whether they want to pick up a fork and eat.” The researchers use a robotic arm mounted on a chair, but first have to train it to carry out its respective functions. To achieve this, they intend to write a program that will evaluate sensor data and recognize the context the user finds them self in and what they are planning to do.

“Whilst we can't peer into the brain," Schmitt explains, "we have to get as close as possible to the decision-making process,” which, he continues, is done by recording eye movements. Muscles tense up a few milliseconds before a given movement, which can be measured via the skin surface using electrodes. “If,” he says, “we can detect the activity early enough, we can merge that information with our biophysical models. Our hope is that this will give us a high probability of determining whether the person will reach for the glass, after which the robotic arm will be able to intervene before the person spills the contents of the glass.” Schmitt only sees the chair with the clunky mechanical arm as an intermediate step in the development of conventional robotics in preparation for what modern, bio-inspired robotics will be capable of in ten to fifteen years' time. “In future, these will be soft-robotic, textile exoskeletons, which already exist in research environments,” he explains: “These will wrap around an arm like a sort of stiff pullover, which we refer to as bionic integration.”

Although we already have artificial muscles, powering the computers and the energy supply are problematic, which is why Schmitt and his team are studying how information is processed in natural systems. “Biological systems can do it: we can hit a dartboard, run, or play the piano all without a huge fast central computer. Of course we have a brain with millions of neurons but it has a relatively low signal processing speed.” Energy is stored in the muscles themselves as well as in the organs. “Everything would seem to suggest the use of distributed processing and energy storage for modern robotic systems," Schmitt explains.

The idea of using simulations to prove things that people instinctively rule out first suggested itself to the researcher as he was preparing his dissertation in theoretical astrophysics in Tübingen under Prof. Hanns Ruder. Schmitt achieved nationwide fame with a simulation of the "bathtub murder" in Rottach-Egern when he demonstrated that it was highly probable that a senior citizen could have fallen into a bathtub and suffered the injuries noted in the autopsy, with no fault on the part of anyone else. Manfred Genditzki, who had been convicted of the murder, was released in 2022 partly on the basis of Schmitt’s expert opinion after the court accepted the simulation of human movements as a new form of evidence.

A retrial is now taking place, with a verdict expected in early July 2023. In the opinion of renowned jurists, an acquittal would be a truly historic event in German judicial history. Never has a person convicted of murder by a jury been acquitted after so many years - and the Stuttgart simulation methods would have played a significant part in this. “Fundamentally, therefore,” says the researcher, “it would be a question of rethinking human forensics. Biophysical simulations could be used to account for the dynamics leading up to an important incident and come to objective conclusions.”

When Schmitt joined the Stuttgart-based Cluster of Excellence in 2008, he was already inspired by then SimTech Director Prof. Wolfgang Ehlers' idea of advancing biomechanics modeling. He founded a junior research group at the Institute of Sport and Movement Science, became a Junior Professor at the University of Stuttgart and was eventually given a professorship at the newly founded IMBS.

The researcher took five months of parental leave for each of his two children and, having realized that this would not be without consequences for his research career, he temporarily took on the position of Gender Equality Officer at SimTech. “The reason I care about equal opportunities is because I believe that the only way to maximize success is to make opportunities equal for everyone and to remove any non research-related hurdles,” Schmitt explains. Where he feels most comfortable, he adds, is in a place where no one asks where you come from, but rather what ideas you bring to the table, which, he says, is how things are at SimTech, which is why he refers to the Cluster of Excellence as his "home town." “It's a new form of interdisciplinary university: our work depends on control engineering, mathematics, physics, electrical engineering, and computer science,” he explains: “In my opinion, the future will be all about breaking down the barriers between disciplines after which we can expect to gain fundamentally new insights.”

The University of Stuttgart's Institute of Industrial Manufacturing and Management (IFF) and Institute for Visualization and Interactive Systems (VIS) and the Institute for Modelling and Simulation of Biomechanical Systems (IMSB) are collaborating with the University of Tübingen's Hertie Institute for Clinical Brain Research (HIH) to develop an intelligent assistance device for people with neurodegenerative movement disorders in the iAssistADL project, which is led by Prof. Dr. Daniel Häufle of the HIH. The requisite software is being developed by a team led by Prof. Syn Schmitt of the IMSB and Prof. Andreas Bulling of the VIS at the Data Integrated Simulation Science Cluster of Excellence (EXC2075).

Editor: Daniel Völpel