Prof. Dr. Heinrich H. Bülthoff
heinrich.buelthoff[at]tuebingen.mpg.de
For full-body motion capture we use two different setups. One setup consists of a leightweight lycra suit with attached reflective markers which are captured and processed with Vicon iQ or Blade software. After the capturing process, the data can be post-processed for the desired need. The second setup is used for real-time motion capture and animation. For this we use two Xsens MVN Suits, consisting of 17 MTx inertial measurement units each. The MVN system software was upgraded in 2014 to MVN Biomech which allows for synchronized 60fps video recordings with an external camera. It also offers integrated data visualization of joint angles and accelerations as well as direct export into game engines like Unity. Custom-built plugins enable the use of these suits for real-time animation (e.g. of virtual avatars). For post-processing and animation of body parts or the full body we use Autodesk 3ds Max, Autodesk Maya and Autodesk Motion Builder. The avatars generally used for experiments involving motion capture and animation are part of the Rocketbox Studios GmbH Complete Characters Library. Through the work of the independent research group, Space and Body Perception (Betty Mohler) in collaboration with the Max Planck Institute for Intelligent Systems (Michael Black) we can now create personalized self-avatars for our experiments. We currently do so for patient populations where we investigate distortions in body image.
GVS is used to stimulate the human vestibular system by injecting small currents behind the ears of a person. Produced by Good Vibrations (Toronto, Canada) it consists of a small box designed to be fastened to a person’s body with 4 leads protruding outward used to attach behind the ears. The newly acquired GVS system will be used in conjunction with the MPI Stewart Platform and the MPS Cyber Motion Simulator to investigate self motion perception with the potential of virtually expanding the usable workspace of these devices. The GVS system will also be used with the tracking hall and the omnidirectional treadmill to enhance redirected walking techniques and to induce out-of-body experiences in virtual environments
Biosignal (EEG, EOG, ECG, EMG) acquisition allows investigation of brain-, heart- and muscle-activity, eye movements, respiration, galvanic skin response and many other physiological and physical parameters. Produced by g.tec medical engineering (Schiedlberg, Austria) it consists of a 16-channel biosignal amplifier (up to 256 channels supported) as well as a portable 8 channel amplifier which enables data acquisition during free movement. The newly acquired g-tec system has been used in conjunction with the MPI Stewart Platform and will in future be used with the MPS Cyber Motion Simulator to investigate biosignal responses to self-motion. High-speed online processing of the g-tec system under MATLAB SIMULINK enables brain computer interfacing. At present the system is capable of controlling cursor movement on a display screen in real-time after training the computer on subject specific activation patterns. Plans to extend this to interfacing the g-tec system with the control computer of the MPI Cyber Motion Simulator will potentially enable the user to control self-motion by monitoring differential activation of the sensorimotor cortex using a motor imagery paradigm.