For most people, closing and opening the hand and gripping objects is quite simple. However, behind this lies a complex interplay of muscles, bones and nerve fibers. However, these can be impaired by diseases such as muscle weakness, spasticity, motor deficits or accidents. In order to restore the gripping ability of a hand, researchers at the Institute of Industrial Manufacturing and Factory Operation (IFF) at the University of Stuttgart have developed a hand exoskeleton.

The hand exoskeleton consists of a central assembly module and individual, movable finger modules. Unlike existing hand exoskeletons, the modules can be individually designed for each patient, especially the finger modules. This allows the patient to spread and move their hand sideways and also move each finger individually. Another advantage of the modular design is that the exoskeleton is easier to handle, allowing patients to put it on independently. Thanks to the open shell system, patients can attach the modules to their hand individually; the modules are then stretched and flexed using motors.

The hand exoskeleton is made from a special plastic that enables the individual modules to be manufactured with a thin wall thickness. This aspect is particularly important for the finger modules. The exoskeleton with motors and electronics weighs approximately 400 g, the hand module weighs around 80 g.

The next steps

The next step in the project will be to control the hand exoskeleton. So far, the module has been connected to EMG and distance sensors as a stand-alone device that can be worn on the forearm in order to initially evaluate the exoskeleton's electromechanical functions. According to the researchers, the exoskeleton will also be controlled by brain waves in the subsequent development phase, which will be combined with eye movements, for example. However, this is being researched by the project partners at Tübingen University Hospital and the University of Tübingen. Scientists at Reutlingen University are working on 3D object recognition, which will allow everyday objects to be recognized and the required grip mode to be preset.

The invention was patented and the German patent was granted.

According to documents from the University of Stuttgart / ag