Acknowledgements
We would like to thank Christian Frede and his team (AmbiGate GmbH, Tübingen) for their contribution to the software of the system and Dr. Winfried Ilg (Centre for Integrative Neuroscience, Tübingen) for useful discussions and consultation. We want to thank our colleagues at BEC GmbH, Fraunhofer IPA and Schön Klinik that contributed to the development and testing of the device. Special thanks go to patients and therapists that volunteered in this study.