Robotic assistive devices are able to enhance physical stability and balance. Smart walkers, in particular, are also capable of offering cognitive support for individuals whom conventional walkers are unsuitable. However, visually impaired individuals often need additional sensorial assistance from those devices. This work proposes a smart walker with an admittance controller for guiding visually impaired individuals along a desired path. The controller uses as inputs the physical interaction between the user and the walker to provide haptic feedback hinting the path to be followed. Such controller is validated in a set of experiments with healthy individuals. At first, users were blindfolded during navigation to assess the capacity of the smart walker in providing guidance without visual input. Then, the blindfold is removed and the focus is on evaluating the human-robot interaction when the user had visual information during navigation. The results indicate that the admittance controller design and the design of the guidance path were factors impacting on the level of comfort reported by users. In addition, when the user was blindfolded, the linear velocity assumed lower values than when did not wear it, from a mean value of 0.19 m/s to 0.21 m/s.

In this paper, we report the development of fiber Bragg gratings (FBGs) arrays in polymer optical fibers (POFs), specifically cyclic transparent optical polymer (CYTOP) fibers, using a femtosecond (fs) laser. The CYTOP is almost transparent to near-ultraviolet and visible light thus femtosecond lasers appear to be a very promising technology for the development of gratings in such fibers. Bearing this in mind, we have applied the direct write, plane-by-plane inscription method to obtain ‘single-peak’ FBGs in long arrays. Following this, we examine the performance of a 5-FBG array applied in a smart walker (SW) and characterized for four different functionalities of the proposed healthcare device. The polymer sensors were used to analyze: (i) structural health monitoring (SHM) of the SW’s mechanical structure, (ii) detection of users’ movement intention, (iii) gait cadence estimation and (iv) detection of floor-induced vibrations for localization and mapping applications. The good results obtained in comparison to commercially available devices show the suitability of the proposed FBG-array on the instrumentation of healthcare devices, where multiple parameters can be measured using the same fiber, which leads to a compact and energy efficient system.

This paper presents a polymer optical fiber (POF) based sensor system for smart walker (SW) instrumentation. The system comprises an oximetry sensor working in reflectance mode, which is embedded in a 3D printed handle for the SW. In addition, there is also a POF-based smart textile that can be integrated in the users’ clothes and is placed on their chest. In this case, the smart textile can detect the displacement caused by the respiration, vibration due to heartbeat and bending induced in the gait. Results show that the proposed sensor system can detect the oxygen saturation, breathing rate, gait cadence and heart rate with errors of about 1 %. In addition, it is proposed an architecture for the SW in which the POF-based sensor system can be applied not only for remote healthcare applications, but also as sensor feedback in cloud robotics for some control paradigms for human-robot interaction. Furthermore, the proposed instrumentation presents the possibility of novel SW control, where the health conditions of the user are considered in the human-robot interaction.

This work presents a multimodal cognitive interaction strategy aiming at walker-assisted rehabilitation therapies, with special focus on post-stroke patients. Such interaction strategy is based on monitoring user’s gait and face orientation to command the displacement of the smart walker. Users are able to actively command the steering of the walker by changing their face orientation, while their lower limbs movement affect the walker’s linear velocity. The proposed system is validated using a smart walker and the results obtained point to the feasibility of employing such cognitive interaction in rehabilitation therapies.

Summary: Despite recent advancements on cloud-enabled and human-in-the-loop cyber-physical systems, there is still a lack of understanding of how infrastructure-related quality of service (QoS) issues affect user-perceived quality of experience (QoE). This work presents a pilot experiment over a cloud-enabled mobility assistive device providing a guidance service and investigates the relationship between QoS and QoE in such a system. In our pilot experiment, we employed the CloudWalker, a system linking smart walkers and cloud platforms, to physically interact with users. Different QoS conditions were emulated to represent an architecture in which control algorithms are performed remotely. Results point out that users report satisfactory interaction with the system even under unfavorable QoS conditions. We also found statistically significant data linking QoE degradation to poor QoS conditions. We finalize discussing the interplay between QoS requirements, the human-in-the-loop effect, and the perceived QoE in healthcare applications.