Designing new input devices and associated interaction techniques is a key contribution in order to increase the bandwidth between users and interactive applications. In the field of Human-Computer Interaction, research and development services in industry and research laboratories in universities have been, since the invention of the mouse and the graphical user interface, proposing multiple contributions including the integration of multiple input devices in multimodal interaction technique. Those contributions, most of the time, are presented as prototypes or demonstrators providing evidence of the bandwidth increase through user studies. Such contributions however, do not provide any support to software developers for integrating them in real-life systems. When done, this integration is performed in a craft manner, outside required software engineering good practice. This paper proposes a systematic process to integrate novel input devices and associated interaction techniques to better support users' work. It exploits most recent interactive systems architectural model and formal model-based approaches for interactive systems supporting verification and validation when required. The paper focusses on Frame-based input devices which support gesture-based interactions and movements recognition but also addresses their multimodal use. This engineering approach is demonstrated on an interactive application in the area of rehabilitation in healthcare where dependability of interactions and applications is as critical as their usability.

Post-stroke or post-brain injuries rehabilitation is a long-term process defined by therapists and tuned to the specific damages and their consequences for each patient. This process requires the definition of well-defined multiple exercises to be performed multiple times by each patient over a long period of time. One of the key findings in the rehabilitation domain is that exercises should be tasks and goals oriented to increase functional independence, enhance development and prevent disability [24]. Patients performing the exercises must be carefully monitored to identify progress, possible regression and prevent damages due to the inadequate performance of the exercises. The SIVIRE tool [20] provides interactive graphical feedback to patients about the performance of their exercises and deviations from nominal, planed practice but fails at providing high-level descriptions of exercises and at connecting them to high-level rehabilitation goals (e.g. gain autonomy in cleaning a room). The HAMSTERS-XLE tool [16] provides a tuneable editor and a simulator to describe goals and task models including low-level tasks covering perception of the various senses, cognition and motoric actions. This paper presents the integration of these two tools and the benefits it brings both to the patients and to the therapists. The resulting tool and its engineering are presented in detail highlighting some generic integration mechanisms. On a case study, we show how exercises can be defined in HAMSTERS-XLE, transferred to SIVRE for fine tuning, monitored by SIVRE during the multiple practices of the patient and transferred back again to HAMSTERS-XLE to monitor progress, identify issues with the exercises and provide therapists with goal and task-based data about patients' evolutions