###### Abstract  
The present study aims to evaluate the advantages of a master-slave robotic rehabilitation therapy in which the patient is assisted in real-time by a therapist. We have also explored if this type of strategy is applicable in a tele-rehabilitation environment. A pilot study has been carried out involving 10 patients who have performed a point-to-point rehabilitation exercise supported by three assistance modalities: fixed assistance (without therapist interaction), local therapist assistance, and remote therapist assistance in a simulated tele-rehabilitation scenario. The rehabilitation exercise will be performed using an upper-limb rehabilitation robotic device that assists the patients through force fields. The results suggest that the assistance provided by the therapist is better adapted to patient needs than fixed assistance mode. Therefore, it maximizes the patient's level of effort, which is an important aspect to improve the rehabilitation outcomes. We have also seen that in a tele-rehabilitation environment it is more difficult to assess when to assist the patient than locally. However, the assistance suits patients better than the fixed assistance mode. master-slave; neurologic rehabilitation; robotic rehabilitation; stroke; teleoperation; tele-rehabilitation +
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and AI methods). However, there is a robotic rehabilitation modality that has received little attention in literature but can provide an additional assistance modality, which is teleoperation. Robotic teleoperation is usually performed by using a master and slave robot model communication. With regards to rehabilitation, this control modality would not only allow the therapist to modify the patient's robot controller parameters but to directly control its movements. Up to now, literature has focused on comparing rehabilitation outcomes of robotic vs. in-person therapies, but there is not any knowledge of what happens when the therapist interacts physically with the patient through the robot. A few works have already presented this teleoperated modality [4; 5; 6], but their research was more focused on the design and control of the robotic system rather than evaluating the advantages and disadvantages of this modality compared to traditional robotic or in-person therapies. Therefore, this work addresses the objective and subjective performance implications of this novel interaction method. Furthermore, it analyzes the differences between interacting through the same robot that the patient is managing or through a teleoperated robot. There are multiple assistance controllers in the literature that differ in the strategy or assistance level provided to the user [7; 8]. In most cases, the level of assistance in a robotic neurorehabilitation system such as the one used in this study (Rubidium) is usually defined based on a previous evaluation of the patient [9]. With the information collected, certain parameters are defined that are maintained throughout the exercise so that the patient can carry it out successfully. With the proposed master-slave teleoperation method, assistance can be further modified in real-time and remotely by the therapist. Our hypothesis is that the real-time assistance provided by a therapist is better adapted to the needs of the patients; thus, it maximizes the effort of the patient. This aspect may improve performance on patient recovery. Furthermore, the final acceptance of any robotic rehabilitation system is dependent on many factors such as cost, patient functional outcomes, patient satisfaction and compliance. Therefore, we also seek to explore if this type of strategy is applicable in a tele-rehabilitation environment, where the social interaction with the patient is more limited compared to being in direct contact with the patient at the clinic.