A Plug-and-Train Robot (PLUTO) for Hand Rehabilitation: Design and Preliminary Evaluation

Abstract

Hand neurorehabilitation involves the training of movements at various joints of the forearm, wrist, fingers, and thumb. Assisted training of all these joints either requires either one complex multiple degree-of-freedom (DOF) robot or a set of simple robots with one or two DOF. Both of these are not economically or clinically viable solutions. The paper presents work that addresses this problem with a single DOF robot that can train multiple joints one at a time – the plug and train robot (PLUTO). PLUTO has a single actuator with a set of passive attachments/mechanisms that can be easily attached/detached to train for wrist flexion-extension, wrist ulnar-radial deviation, forearm pronation-supination, and gross hand opening-closings. The robot can provide training in active and assisted regimes. PLUTO is linked to performance adaptive computer games to provide feedback to the patients and motivate them during training. As the first step toward clinical validation, the device's usability was evaluated in 45 potential stakeholders/end-users of the device, including 15 patients, 15 caregivers, and 15 clinicians with standardized questionnaires: System Usability Scale (SUS) and User Experience Questionnaire (UEQ). Patients and caregivers were administered the questionnaire after a two-session training. Clinicians, on the other hand, had a single session demo after which feedback was obtained. The total SUS score obtained from the patients, clinicians, and healthy subjects was 73.3 ± 14.6 (n = 45), indicating good usability. The UEQ score was rated positively in all subscales by both the patients and clinicians, indicating that the features of PLUTO match their expectations. The positive response from the preliminary testing and the feedback from the stakeholders indicates that with additional passive mechanisms, assessment features, and optimized ergonomics, PLUTO will be a versatile, affordable, and useful system for routine use in clinics and also patients’ homes for delivering minimally supervised hand therapy.