Papers for

physical rehabilitation device designers

Papers whose findings have a practical use for this group, as judged from the abstract. Open a paper to read what it means in practice.

Personalizing exoskeleton assistance by learning user preferences across conditions

Context-Continuous Preference Learning for Exoskeleton Personalization

Abstract: Personalizing exoskeleton assistance across operating conditions is constrained by the time and physical effort required to collect user feedback. We examined whether a user's preference landscape varies smoothly across operating conditions and when this continuity supports learning from limited feedback. We propose Context-Continuous Preference Learning (CCPL), a Gaussian-process preference model that shares observations across nearby contexts while retaining context-specific utility estimates. We evaluated CCPL through simulations and retrospective analyses of ankle and elbow exoskeleton preference data from nine healthy adults. In simulations, CCPL improved reconstruction and preference-based Bayesian optimization relative to independent learning when preferences varied smoothly, but showed negative transfer when continuity was weak. In both human studies, full-data reference landscapes estimated separately for each participant and context tended to be more similar between nearby operating conditions. With five exposures per context, CCPL increased mean reconstruction correlation with these references from 0.644 to 0.720 for ankle assistance and from 0.476 to 0.526 for elbow assistance relative to independent learning. The five-exposure budget was approximately 37% lower for ankle and 17% lower for elbow than the estimated independent-learning budgets needed to match these correlations. CCPL also improved held-out response prediction relative to independent learning, while benefits over pooled learning varied. These findings support context continuity as a basis for sharing preference observations under limited feedback, although benefits for online personalization in humans remain to be established.

Wed 23 SeptMachine LearningRobotics
The gist
Adjusting exoskeletons to work well for different tasks or environments usually needs lots of user feedback, which is tiring and slow. The authors developed a method that assumes users’ preferences change smoothly as conditions change, allowing the system to learn from fewer feedback examples. Their method combines information from similar situations to better estimate what users prefer, improving over learning each condition separately. Tests with simulations and real data showed it can predict preferences more accurately while needing less feedback, though benefits depend on how smoothly preferences actually vary.
Open → 2609.28427v1