Psychophysiological Assessment of Exoskeleton-Assisted Treadmill Walking

Abstract

Despite being able to derive quantitative data on motor performance, rehabilitation robots typically do not provide information on users' subjective experience, and in particular on their psychophysiological state. The aim of this work was the development of a method for the psychophysiological assessment of users whose treadmill walking is assisted by a lower limb exoskeleton. Four indicators were estimated based on physiological data by using a Fuzzy logic approach. The assessment of human-exoskeleton interaction was performed on a group of four healthy participants and the correlation between different pairs of indicators was evaluated.

Benchmarking the Effects on Human–Exoskeleton Interaction of Trajectory, Admittance and EMG-Triggered Exoskeleton Movement Control

“…Table 5 shows the PIs obtained from the EXPERIENCE software averaged across subjects for the TC, AC and OC walking conditions. The PIs Acceptability, Functionality and Usability were rated above 4 out of 7, indicating that the users reported the exoskeleton and the associated walking condition as positive , comfortable and safe , easy to use and robust , and highly usable , respectively, according to the PI definitions provided in [ 36 , 37 ]. Regarding Perceptibility, the average value was below half of the scale, indicating that the users perceived the exoskeleton and the associated walking conditions as slightly negative emotion in terms of embodiment , agency and attachment [ 36 , 37 ].…”

“…EXPERIENCE and PEPATO protocols were used to compare the effects on human–exoskeleton interaction, as well as user perception, of the different control strategies described in Section 2.3 . The EXPERIENCE protocol [ 36 , 37 ] aims at providing a benchmarking methodology for measuring both the user’s subjective perspective of the use of the exoskeleton by a newly developed multi-factor questionnaire and also to derive psycho-physiological indicators based on physiological data gathered during an exoskeleton-assisted walking test. EXPERIENCE testbed requires measuring ECG, GSR and the BR while walking.…”

“…As described in Section 2.4 , EXPERIENCE aims at measuring both the user’s subjective perspective of the use of the exoskeleton through questionnaires and psycho-physiological indicators based on physiological data—ECG, GSR, and BR. The PIs can yield a maximum value of seven points, which are calculated from the answers to the questionnaire provided by the testbed (extracted from [ 36 , 37 ]): Usability: This is defined as the extent to which the exoskeleton can be used by the users to achieve specified goals with effectiveness, efficiency, and satisfaction in this specified context of use. High value of this PI indicates that the robot is highly usable.…”

“…All PIs were calculated using the software available at the EUROBENCH facility at Hospital Los Madroños . Further details on the processing method and algorithms are available in [ 36 , 37 ]. The resulting PIs were averaged across walking conditions.…”

“…In this work, we are therefore users of EUROBENCH’s project results. As shown in detail in Section 2 , we designed our experimental protocol with the two testbeds most suitable for our objective, which are the EXPERIENCE [ 36 , 37 ] and PEPATO [ 38 ] testbeds: the EXPERIENCE testbed aims at evaluating the user’s physiological response and subjective experience during exoskeleton-assisted walking on a treadmill, while the PEPATO testbed aims at analyzing muscle coordination during exoskeleton-assisted gait. More details are provided in Section 2 .…”