The Role of Physical and Digital Prototyping in Designing Wearable for Rehabilitation - Case Study of a Digital Exergame
Authors: Tasca Paolo , Giovannini Chiara , Cavaliere Fedele , Noli Chiara , Celauro Alessandro , Covarrubias Mario , Perego Paolo 
Published: October 2023

Prototypes are an excellent tool to actualize an idea or a concept. As reported by different methodologies (Double Diamond, Design Thinking), prototypes enable designers to quickly iterate and learn from their designs. Their advantages are not limited to this aspect: by iteratively increasing the level of complexity from one version of the prototype to the next one, they can help enhance the skill set of a person through a learning-by-doing approach. This iterative process allows for the identification of unknown unknowns and can lead to the development of innovative solutions in various contexts, including biomedical engineering and rehabilitation. The multiple iterations and learning processes, inherent in the rehabilitation phase are a great asset when facing biomedical projects, which require multidisciplinary knowledge. The purpose of this paper is to provide supporting evidence for the importance of prototypes in biomedical design as tools to fill the skill gap, by presenting a real-world case study performed in an academic context. A team of university students developed a novel solution for post-stroke rehabilitation, DEUHR (Digital Exergame for Upper Limb and Hand Rehabilitation), based on innovative trends in biomedical technologies, such as motion tracking sensors and exergames. The paper reports the entire process for the design of the rehabilitation system, starting from the initial concept, prototypes, tests with the users, and final outcomes.The concept for DEUHR was first developed through a series of brainstorming sessions and analysis of existing rehabilitation solutions. The team then moved on to creating low-fidelity prototypes to test and refine the interaction design and gameplay mechanics of the exergame. These low-fidelity prototypes allowed the team to quickly iterate and gather feedback from potential users, including stroke patients and rehabilitation therapists. Based on the feedback received, the team made several iterations and improvements to the prototype, gradually increasing the level of complexity and fidelity. This iterative process of prototype development allowed the authors to improve the functionality and usability of DEUHR. To evaluate the usability and effectiveness of DEUHR, a high-fidelity prototype was created in the form of a tablet-based exergame for training. New tests with both the high-fidelity prototype connected with the wearable device were made with users in order to test the functionality and usability altogether.This paper outcome consisted of a demonstrator merging the three main components of the project (the exergame, the sensing unit, and the app) which were later tested on patients. Even if the case study concerned the design of health monitoring devices, it provided valuable insights with respect to the UX design process and allowed the team to grow and expand their initial skill set to meet the requirements needed. This experience led to a rethinking of the prototyping process as an enhancing and engaging opportunity to be featured in a learning environment – possibly extending its validity also outside of the biomedical field.