## 3 Home Rehabilitation Software Prototype for Young People
### Improvements over an Existing Prototype for Home Rehabilitation  
Based on the outcomes extracted from the SMS, some improvements have been developed to be integrated in the this prototype for home rehabilitation. * **Autonomy. ** Initially, the prototype rehabilitation software was designed to support rehabilitation at home, trying to minimize the installation instructions, as well as the ICT skills that a patient should possess. However, the system suffered from a lack of autonomy, in the sense that it had to be connected to an external computer to start up the application. Therefore, taking into account this consideration and the characteristics of the systems studied, the design of a low-cost device has been considered, which integrates an _Intel Next Unit of Computing (NUC)_ small PC along with the device _Microsoft Azure Kinect Developer Kit (DC)_ ([[https://azure.microsoft.com/es-es/services/kinect-dk](https://azure.microsoft.com/es-es/services/kinect-dk)]([https://azure.microsoft.com/es-es/services/kinect-dk](https://azure.microsoft.com/es-es/services/kinect-dk))). Thus, we reduce the connections and facilitate the installation to the user, only connecting the device as-a-whole to the TV. This improvement was addressed by directly replacing previous hardware devices with new ones. This particularly affects the tracking device, since we replaced the deprecated Microsoft Kinect with the device _Microsoft Azure Kinect DK_. Since we developed and maintained an internal API to collect data from the tracking device, and since this API has not been changed, there was no impact when replacing the device. * **Monitoring and supervision**. The initial version of the system favored a mixed approach based on synchronous and asynchronous feedback. Thus, it was able to assess, in real-time, the patients' degree of success regarding their physical activity. At the same time, the therapist was able to supervise the patients' evolution once they have finished the exercise routine, which involves asynchronous supervision. However, the former version of the system lacked detailed monitoring when it came to monitor the patient's activity, such as the information related to the mobility of certain body areas. In other words, it was not metrics-oriented. For this reason, the current prototype includes the design of different metrics or indicators. Two examples are performance and mobility. Their objective is to provide the therapist with relevant  
Figure 2: Graphical user interface of the prototype: (1) view for selecting the game mode; (2) view for selecting exergames depending on the involved joint/s; (3) view of one of the exercises that can be performed thanks to the proposed software prototype for home rehabilitation. information about the patients' activity in order to measure the evolution of their therapy. The integration of this improvement was possible thanks to the use of Personalized Exergame Language (PEL) [60], which allowed us to define key performance indicators. These can be activated depending on the therapeutic goals of each exergame. * **Natural interaction**. The interaction type is another feature that makes rehabilitation possible at home. After carrying out the SMS, it has been identified that interaction is not intuitive enough, that is, patients cannot understand which joint to use or which is the movement they have to do to achieve the task. For this reason, we have developed some advanced interactions. For example, the joints are colored in red so that the patient must know which ones have to be used to do the exercise, or the virtual spheres that are ordered regarding their size, i.e., from bigger to smaller to indicate the trajectory a patient must follow. Apart from this, another drawback was considered, which concerns the navigation through our system by means of classic desktop interaction devices. In this sense, and considering the proposals of the cited works, we have enabled a natural interaction using voice commands.