**Acknowledgements**

This work has been partially funded by the European Commission 7th Framework Programme (FP7) under the sub-grant 'Dr. Ara - A Medical Device for 6 Billion People' of project #632913 Future Internet Challenge eHealth (FICHe), and by the Portugal 2020 European Regional Development Fund under the grant #17863, Physio@Home—Extending Physiotherapy Programs to People's Homes.
