Ranzani R1, Veerbeek JM2,3, Engelbrecht B4, Lambercy O1, Luft AR2,3, Gassert R1, Held JPO2,3,5
1ETH Zurich, Rehabilitation Engineering Laboratory, Department of Health Sciences and Technology, Zurich, Switzerland, 2University of Zurich and University Hospital Zurich, Division of Vascular Neurology and Neurorehabilitation, Department of Neurology, Zürich, Switzerland, 3Cereneo, Center for Neurology and Rehabilitation, Vitznau, Switzerland, 4Zürcher RehaZentrum Wald, Department of Physiotherapy, Wald, Switzerland, 5University of Twente, Biomedical Signals and Systems, MIRA – Institute for Biomedical Technology and Technical Medicine, Enschede, Netherlands
Background: Upper limb function and cognition are often affected after stroke [1, 2]. To effectively train the upper limb in stroke patients, it is important to provide intensive, specific and enriched interventions [3, 4]. This can be challenging for healthcare providers due to economical and organizational limitations. A possible solution are self-directed rehabilitation interventions at home [5], which can be supported by robotic technologies. An example is the ReHapticKnob that has been developed to treat hand function [6] and complement standard upper limb therapy. To enable self-directed, unsupervised therapy, a new patient-centered user-interface and therapy games have been developed.
Purpose: The objective is to evaluate the usability of a new patient-centered user-interface and two new therapy games for the ReHapticKnob robot in chronic stroke patients.
Methods: In this usability study, chronic stroke patients (≥18 years) who could voluntarily flex/extend the fingers of the paretic side were enrolled. During a single supervised session, patients tested the user-interface (e.g., color code) and played two therapy games (Tunnel Game and Sphere Catching Game). The performance was evaluated with a checklist. In the post-evaluation interview, the usability and the patients' self-rated performance was assessed using the System Usability Scale (SUS) [7] and the Raw-TLX [8]. The participants gave written informed consent in accordance with the declaration of Helsinki. The study was approved by the Cantonal Ethics Committee Zurich, Switzerland (Req-2017-00642). Numbers are presented as median, interquartile range.
Results: Ten ischemic stroke patients (60.5, 56.3-67.5 years old, 39.5, 27-60.5 months poststroke) with mild-to-moderate upper limb motor impairment (Fugl-Meyer Assessment - Upper Extremity 43, 40.3-51.5) were included. All patients, with the exception of one, responded with excellent scores on the SUS (85, 75.6-86.9 out of 100) for controlling the system (user-interface) and good rating (73.8, 63.1-83.8) for the two games embedded in the ReHapticKnob. Nine out of ten stroke patients stated that they would use the ReHapticKnob frequently. The oldest stroke patient (87 years) scored worse on all usability scales. In the Raw-TLX, the user-interface required a low effort level of 29.2 ±26.0%, which is still higher compared to the target effort level of 8% set during the design of the user-interface. The therapy games required a subjective effort level above 43%, which is in line with the target effort level of 42% set for the therapy exercises. The performance checklist revealed that the most difficult tasks to execute were object catching and recognition in the Sphere Catching Game. Here, patients have to orient the hand in a specific angle, grasp a virtual object, and probe its mechanical properties rendered by the robot. Two out of 10 subjects successfully performed this task.
Conclusion(s): Chronic stroke patients were able to control the ReHapticKnob with the new patient-centered interface and liked to use the therapy games more frequently. The feasibility and efficacy of unsupervised training with the system should be investigated.
Implications: The ReHapticKnob has the potential to deliver intensive therapy for stroke patients with a mild-to-moderate upper limb paresis outside the supervised clinical rehabilitation setting.
Keywords: Robotic, Upper Limb, Stroke
Funding acknowledgements: This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No.688857 (SoftPro)
Purpose: The objective is to evaluate the usability of a new patient-centered user-interface and two new therapy games for the ReHapticKnob robot in chronic stroke patients.
Methods: In this usability study, chronic stroke patients (≥18 years) who could voluntarily flex/extend the fingers of the paretic side were enrolled. During a single supervised session, patients tested the user-interface (e.g., color code) and played two therapy games (Tunnel Game and Sphere Catching Game). The performance was evaluated with a checklist. In the post-evaluation interview, the usability and the patients' self-rated performance was assessed using the System Usability Scale (SUS) [7] and the Raw-TLX [8]. The participants gave written informed consent in accordance with the declaration of Helsinki. The study was approved by the Cantonal Ethics Committee Zurich, Switzerland (Req-2017-00642). Numbers are presented as median, interquartile range.
Results: Ten ischemic stroke patients (60.5, 56.3-67.5 years old, 39.5, 27-60.5 months poststroke) with mild-to-moderate upper limb motor impairment (Fugl-Meyer Assessment - Upper Extremity 43, 40.3-51.5) were included. All patients, with the exception of one, responded with excellent scores on the SUS (85, 75.6-86.9 out of 100) for controlling the system (user-interface) and good rating (73.8, 63.1-83.8) for the two games embedded in the ReHapticKnob. Nine out of ten stroke patients stated that they would use the ReHapticKnob frequently. The oldest stroke patient (87 years) scored worse on all usability scales. In the Raw-TLX, the user-interface required a low effort level of 29.2 ±26.0%, which is still higher compared to the target effort level of 8% set during the design of the user-interface. The therapy games required a subjective effort level above 43%, which is in line with the target effort level of 42% set for the therapy exercises. The performance checklist revealed that the most difficult tasks to execute were object catching and recognition in the Sphere Catching Game. Here, patients have to orient the hand in a specific angle, grasp a virtual object, and probe its mechanical properties rendered by the robot. Two out of 10 subjects successfully performed this task.
Conclusion(s): Chronic stroke patients were able to control the ReHapticKnob with the new patient-centered interface and liked to use the therapy games more frequently. The feasibility and efficacy of unsupervised training with the system should be investigated.
Implications: The ReHapticKnob has the potential to deliver intensive therapy for stroke patients with a mild-to-moderate upper limb paresis outside the supervised clinical rehabilitation setting.
Keywords: Robotic, Upper Limb, Stroke
Funding acknowledgements: This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No.688857 (SoftPro)
Topic: Robotics & technology; Neurology: stroke; Neurology
Ethics approval required: Yes
Institution: Cantonal Ethics Committee Zurich
Ethics committee: Cantonal Ethics Committee Zurich
Ethics number: Req-2017-00642
All authors, affiliations and abstracts have been published as submitted.
