FriWalk robotic walker: usability, acceptance and UX evaluation after a pilot study in a real environment.

Background: Scientific evidence supports that prevention strategies like multicomponent physical exercise help avoiding functional decline, falls and frailty. The robotic walker FriWalk, developed within the ACANTO project, supports the execution of controlled physical activities during hospital admission to prevent functional deterioration associated to prolonged bedrest. FriWalk shows in a clinical validation study a positive relationship with improvement in physical performance, basic activities of daily living execution and frailty status. Usability, acceptance and user experience (UX) are key aspects to ease the adoption of assistive technologies in the elderly.Objective: This work pursues the evaluation of the usability, acceptance and UX of the FriWalk from the patients and clinical professionals' perspectives.Methods: Data collected during the validation of FriWalk in a real environment have been used. Forty-two patients recruited at Getafe University Hospital (Acute Care and Orthogeriatric Units) and one clinical professional participated. SUS, TAM, UX and ad hoc questionnaires were administered.Results: Patients provided an average SUS of 52.86 and provided valuable information in the qualitative acceptance interviews. The clinical professional provided an averaged SUS and TAM of 67 and 46.6, respectively, and evaluated all UX categories as above average.Conclusions: Usability results do not qualify FriWalk as above average; the reasons explaining this have been identified and point out to the prototypical stage of the hardware. Acceptance and UX were positively evaluated and allowed the research team to propose a new organizational model to deliver the FriWalk-based prevention program. FriWalk will be soon evolved.Implications for rehabilitationFriWalk showed in a randomized clinical trial a positive relationship with improvement in physical performance, basic activities of daily living execution and frailty status.In terms of usability, user experience (UX) and acceptance, participants of the study have valued the FriWalk robotic walker as a promising help, considering that the device that has been under evaluation was still in a prototype stage.Clinical professional reported FriWalk and its corresponding exercise program description software regarding usability, acceptance and UX as satisfactory tool to prescribe and assess a rehabilitation program for hospitalized patients.

Combining Haptic and Bang-Bang Braking Actions for Passive Robotic Walker Path Following.

Robotic walkers are a promising solution for physical and cognitive support to older adults. This paper proposes a low cost path following strategy combining the advantages of a simple mechanical braking guidance, such as safety, passivity, and a low cost, and the ones of a vibrotactile haptic guidance, such as comfort and portability. The user is guided by providing indications on the directions of motion using the haptic interface so that he/she can autonomously and comfortably follow the planned path. However, whenever the user significantly departs from the path (for instance, s/he gets too close to obstacles), the braking system kicks in to safely steer the user back along the proper direction. The formal correctnesses of the hybrid strategy ruling the combination of the two guidance systems is proved theoretically. Moreover, a comprehensive experimental study with users aged 64 to 100, including also psychological evaluations, has been performed. The hybrid combination of the braking and the haptic guidance systems is shown to outperform the two individual approaches in isolation. The combination of the two retains the same level of the users' perceived comfort typical of the haptic-only guidance while ensuring the adequate path following performance typical of the braking-only guidance. In particular, the combined approach produces a mean path following error equal to 41% of the mean path following error ensured by the haptic-only approach. Conversely, thanks to the haptic feedback, the combined approach halves the activation time and the number of interventions needed in the braking-only approach.