# A Case Study on the Design and Implementation of a Platform for Hand Rehabilitation
## 3 The Motivation for RehabHand  
There is a strong belief that, in the next decades, the human-computer interaction [28; 29] in forthcoming systems will evolve and change permanently. We can already see many examples (gesture-controlled systems, speech, etc.). Here, one of the research topics is also to develop solutions that allow users who do not have a background in programming to develop their own applications [30]. This research topic is more known under End-User Programming or End-User Development (EUD) [21], supported with the usage of domain-specific language technology [17]. The idea behind EUD is to empower domain experts to express the desired functionality easily, without dealing with low-level software technologies (using frameworks, libraries, etc. ), but develop programs with abstractions from a domain they know well. In this way we developed our platform RehabHand, to support therapists to write exercises in natural and domain-specific terminology. There are many benefits of such a development. On one hand, a therapist can prepare personalized exercises that are also readable for the patients. On the other hand, we foster the building of a community of domain experts who _speak the same language_, the language of RehabHand. Hence, they can share their exercises and related knowledge effectively with their colleagues. Since treatments are standardized, results can be compared between patients. The other motivation for RehabHand is connected with the selection of devices for rehabilitation aid. Of course, the selection is driven by the specific treatment we would like to support. However, we can still be faced with the decision between several devices. We do not want to be tied to a single device; therefore, our idea was to prepare a platform which can be extended with a new rehabilitation hand. Many practical reasons exist for such independence from the hardware. If the currently used rehabilitation device does not cover our needs anymore, we can replace it with a different one. The up-front cost, level of effort, assumed risk, and latency required to make the software transition to adopt new hardware are minimized in our hardware-independent platform RehabHand. In Figure 1a traditional software-hardware relationship is compared to the RehabHand platform. In traditional development, manufacturers provide their own software for their devices. There is no connection between different software solutions. In RehabHand, a unified software is connected with a platform that is responsible for connecting different devices. As will be shown, RehabHand can be used, even if we custom develop our own RehabHand with 3D printing and use it instead of commercial solutions. RehabHand lowers the hardware adoption barrier, enabling software to achieve the benefits of RehabHand software customization with significantly less transition time and effort. Currently, as a proof of concept, our platform supports three different rehabilitation hands, but can be extended upon request. All three rehabilitation hands have minimal and elementary functionality, but there are groups of patients with associated disabilities--besides hand movement, they also have hearing, vision, spatial awareness, and so forth. Although our examples are rather simple rehabilitation tools, such rehabilitation aids represent indispensable assistance in the rehabilitation process. The next, but not least, motivations for RehabHand are the possibilities opened with such a platform. Recall the second usage scenario from Section 2, using a rehabilitation aid at home. Since the material for 3D printing, microcontrollers, micro-servos and other electronic elements are affordable, we can construct a rehabilitation tool with local production (upon given design instructions). This ability provides a solution for many emerging challenges in the rehabilitation we are dealing with. Imagine the time and effort of the elderly needed to come to rehabilitation centers.