Towards a mobility diagnostic tool: Tracking rollator users' leg pose with a monocular vision system

Abstract

Abstract-Cognitive assistance of a rollator (wheeled walker) user tends to reduce the attentional capacity of the user and may impact her stability. Hence, it is important to understand and track the pose of rollator users before augmenting a rollator with some form of cognitive assistance. While the majority of current markerless vision systems focus on estimating 2D and 3D walking motion in the sagittal plane, we wish to estimate the 3D pose of rollator users' lower limbs from observing image sequences in the coronal (frontal) plane. Our apparatus poses a unique set of challenges: a single monocular view of only the lower limbs and a frontal perspective of the rollator user. Since motion in the coronal plane is relatively subtle, we explore multiple cues within a Bayesian probabilistic framework to formulate a posterior estimate for a given subject's leg limbs. In this work, our focus is on evaluating the appearance model (the cues). Preliminary experiments indicate that texture and colour cues conditioned on the appearance of a rollator user outperform more general cues, at the cost of manually initializing the appearance offline.

Development of a video-based technique for ambulatory monitoring of foot placement with an instrumented rollator

“…coloured, inter-locking brick walkways). As a result, foot position tracking procedures may be enhanced by switching to an active marker system or a marker-less tracking method (16), as employed in previous work. Alternatively, multiple cameras or portable depth camera solutions may also provide a method that improves tracking.…”

Chasing Feet in the Wild: A Proposed Egocentric Motion-Aware Gait Assessment Tool

“…There are relatively few previous works aiming to extract spatial gait parameters using FPV. An interesting and novel approach was using a walker-mounted depth and/or color camera to estimate 3D pose of lower limbs, mainly in frontal plane [35,18,31]. To achieve this, Ng et al [31] used general appearance model (texture and colour cues) within a Bayesian probabilistic framework.…”

“…An interesting and novel approach was using a walker-mounted depth and/or color camera to estimate 3D pose of lower limbs, mainly in frontal plane [35,18,31]. To achieve this, Ng et al [31] used general appearance model (texture and colour cues) within a Bayesian probabilistic framework. In [18], a Kinect (depth) sensor along with two RGB cameras were placed on a moving walker, and the 3D pose was formulated as a particle filtering problem with a hidden Markov model.…”

Design of a home multi-robot system for the elderly and disabled

“…Few "Smart rollators" have been developed by different groups and focus on improving key parts of the design. Focuses include collecting data [17], determining intent of the user and assisting for navigation purposes [18,19], braking for stability purposes [20], and estimations of leg pose at the viewpoint of the rollator [21]. Each of these different designs have similarities in that all concern primarily on how the user is doing while operating the machine.…”