## 2 Materials and Methods  
All components of the newly developed teletherapy solution (technology platform and service model) were developed employing a holistic Human Centered Design approach (ISO 9241-210:2019, 2019) [13] by conducting iterative workshops, focus groups, and interviews with experts [14]. The service model not only complements but also comprehensively supports existing rehabilitation structures. It offers three core processes needed to provide qualitative, patient-centered, tele-therapeutically supported rehabilitation: face-to-face therapy (in person), synchronous therapy (via video calls), and asynchronous training (patient trains, the therapist monitors time independently). In addition to these core processes, the service model provides all necessary structures and processes to enable this form of rehabilitation. The technology platform, designed to support patients in the subacute and chronic phase after their rehabilitation stay, offers a flexible approach. It can be used for teletherapy under the supervision of clinical therapists or integrated into the therapeutic process with freelance therapists. The technology platform can already be introduced during the treatment in rehabilitation centers to help patients familiarize themselves with it. It is always the therapist's decision whether and when teletherapy (in which rehabilitation phase) is appropriate. The technology platform consists of the following components: a tablet and an Android app for patients, a web-based user interface for therapists, a backend that enables data exchange and storage, and a device for hand and finger rehabilitation (TYROMOTIONPablo (TYROMOTION, Graz, Austria [[https://tyromotion.com/en/products/pablo/](https://tyromotion.com/en/products/pablo/)]([https://tyromotion.com/en/products/pablo/](https://tyromotion.com/en/products/pablo/)) (accessed on 12 August 2024)). The technology platform offers different possibilities to support rehabilitation and training processes and has six main functions:  
1. Patient data administration: Therapists can administer patient data, such as personal information, ananness, or assessments, and then define the therapy goals. Patients can view their personal data and their current therapy goals on the tablet. 2. Exercise program: The core feature of the technology platform is the planning and instruction for performing exercises (incl. Pablo). Therapists can create exercise programs with descriptions, pictures, or videos and individualize these (duration, sets, repetition) for each patient. The exercise programs are scheduled in the patient app calendar. For the serious game with [PERSON], the therapist can set the game level, time, and force level (of maximum grip force)
3. Activity monitoring: Statistical data and visualization of conducted exercises, success rate (games), or measured parameters (e.g., grip force from [PERSON]) are displayed on the patient's user interface and, with more details, also on the therapist's user interface, to show the history and the progress of conducted exercises. The data are transmitted to the therapist's interface after the exercise has been completed. The check whether an exercise has been performed correctly takes place via video call and the visual assessment from the therapist. 4. Communication: A video call function (with QuickBlox) has been implemented for synchronous teletherapy sessions. The patient and therapist can also use a chat for asynchronous communication (e.g., scheduling or postponing an appointment). 5. Feedback and diary: Before and after performing exercises, the patient is asked to give feedback on the daily condition. Additionally, a private diary is available for the patient. The content of this diary is not visible to the therapist. 6. Therapy reporting: The therapist's platform also offers a documentation tool for progress reporting and also to report possible complications or side effects of the training.