The Laboratory of Multimedia Applications and the Simulation and Movement Analysis Lab, of the Universitat Politècncia de Catalunya, are developing Unity applications to help the rehabilitation of stroke patients (based on virtual reality and motion capture). See a video of one session of measurements: https://www.youtube.com/watch?v=pwcY-Ox6rWE.
The internship holder will be responsible of improving these applications and doing measurements with the subjects. He/she will basically work with C#, since will need to improve the application in Unity, php to modify the datebase, and a bit of Arduino (to collect data of a force sensor). It is recommended to have experience in some of these languages.