Prosthetics, exoskeleton, organ-on-a-chip: Klee Prize 2025 goes to work with high benefits for patients

(Frankfurt a. M., 12.06.2025) Together with the Klee Family Foundation, the German Society for Biomedical Engineering within VDE (VDE DGBMT) awards the Klee Prize once a year to promote young scientists. In 2025, the prize was awarded to three pieces of work that have a particularly high benefit for the treatment of patients. The focus is on knee prostheses and exoskeletons, two medical technology products that are used directly on humans, as well as improvements for pharmaceutical research with the topic of organ-on-a-chip.

Perfect Match: improving the size and accuracy of fit of knee implants

The first prize of EUR 5,000 goes to Dr.-Ing. Sonja Ehreiser (RWTH Aachen) for her work on improving care in knee arthroplasty. Knee replacement is one of the most frequently performed operations worldwide, with more and more younger patients requiring the treatment. So far, however, the proportion of dissatisfied patients after surgery has been relatively high. Sonja Ehreiser explains: "The knee is a joint that has to meet very high standards as a prosthesis. Through my work, I want to help improve the quality of life after the operation." 

Ehreiser has analyzed a database of over 85,000 knee joints to determine what sizes implants should have. The range of standard implants available to date is based on relatively small data sets from a few hundred patients. "If the sizes of the implant systems are adapted to reality, patient coverage can be improved by 19 to 26 percent." The work also shows how the accuracy of fit can be optimized in terms of form and function by means of an individual fit assessment for implants. Ehreiser is now head of AI development for orthopaedic planning software at mediCAD but has passed the project on to a successor at the institute.

Exoskeletons with control technology: support the musculoskeletal system, not replace it 

Disorders of the musculoskeletal system as a result of strokes affect many people worldwide, whereby conventional therapies are very costly and require many resources. Robotic rehabilitation systems can support the process but must enable patients to initiate movements themselves. Dr.-Ing. Lukas Bergmann explains: "In the long term, research into exoskeletons can make a significant contribution to supporting people with musculoskeletal disorders. The exciting thing for me is that control technology is used here in a way that has a very high practical relevance."  

In the first part of his work, Bergmann describes the hardware design of an active exoskeleton with actuators that enables safe coupling between humans and the exoskeleton. To this end, he has developed a cooperative controller that estimates and supports the user's joint torques in real time. "New colleagues have been recruited at the institute to pursue the developed approach. I myself have turned my career towards robotics at ANYbotics and founded a start-up with my wife in which we use control technology to control motorized bicycle trailers for children."

Organ-on-a-chip with 3D bioprinting: developing drugs without side effects

In pharmaceutical research, the complexity of human organs needs to be mapped in the tissue models currently available. In animal experiments or clinical studies, however, the next step often reveals unexpected side effects or low drug efficacy because the models are not accurate enough. Dr.-Ing. Anna Moritz-Fritschen explains: "In my dissertation, I developed a 3D bioprinting process with which allows different cell types and matrix materials to be placed with high spatial resolution." To create a three-dimensional cancer model supplied with capillary vessels within 14 days, she combined human liver cancer cells with blood vessel and connective tissue cells. This model was integrated onto a microfluidic chip and connected to a pump system so that the resulting organ-on-a-chip can be used to realistically simulate the supply of nutrients to the cells and the uptake of active pharmaceutical ingredients.

"The need for this research is immense," says Moritz-Fritschen. "The FDA (U.S. Food and Drug Administration) approved alternatives to animal testing for the first time two years ago. Accurate models help to avoid late failures and thus high development costs for products that are not successful." In order to continue working in medical-pharmaceutical research, she has taken up her current position as a group leader at TU Darmstadt with a focus on biomedical devices.

About the German Society for Biomedical Engineering within VDE (VDE DGBMT)

The German Society for Biomedical Engineering within VDE (VDE DGBMT) is the scientific and technical society for medical technology in Germany. It was founded in Frankfurt am Main in 1961.  

The DGBMT in the VDE brings together experts from all areas of technology applications in medicine and deals with the entire range of topics in biomedical technology. It organizes conferences and workshops for expert audiences and is the sponsor of two international scientific journals: Biomedical Engineering and Current Directions in Biomedical Engineering published by Walter de Gruyter. Position papers, statements and expert contributions discuss current topics independently and neutrally. In addition, the DGBMT awards promotional prizes for young scientists, for scientific excellence and innovation, and for patient safety in biomedical engineering. Last but not least, it represents German biomedical engineering in international bodies.  

For more information, visit www.vde.com/dgbmt

About VDE

VDE, one of the largest technology organizations in Europe, has been regarded as a synonym for innovation and technological progress for more than 130 years. VDE is the only organization in the world that combines science, standardization, testing, certification, and application consulting under one umbrella. The VDE mark has been synonymous with the highest safety standards and consumer protection for more than 100 years. 

Our passion is the advancement of technology, the next generation of engineers and technologists, and lifelong learning and career development “on the job”. Within the VDE network more than 2,000 employees at over 60 locations worldwide, more than 100,000 honorary experts, and around 1,500 companies are dedicated to ensuring a future worth living: networked, digital, electrical.  
Shaping the e-dialistic future. 

The VDE (VDE Association for Electrical, Electronic & Information Technologies) is headquartered in Frankfurt am Main. For more information, visit www.vde.com