Characterisation of rollator use using inertial sensors

Abstract

The use of walking aids is prevalent among older people and people with mobility impairment. Rollators are designed to support outdoor mobility and require the user to negotiate curbs and slopes in the urban environment. Despite the prevalence of rollators, analysis of their use outside of controlled environments has received relatively little attention. This Letter reports on an initial study to characterise rollator movement. An inertial measurement unit (IMU) was used to measure the motion of the rollator and analytical approaches were developed to extract features characterising the rollator movement, properties of the surface and push events. The analytics were tested in two situations: first, a healthy participant used a rollator in a laboratory using a motion capture system to obtain ground truth. Second, the IMU was used to measure the movement of a rollator being used by a user with multiple sclerosis on a flat surface, cross-slope, up and down slopes and up and down a step. The results showed that surface inclination and distance travelled measured by the IMU have close approximation to the results from ground truth; therefore, demonstrating the potential for IMU-derived metrics to characterise rollator movement and user's pushing style in the outdoor environment.

Walking with rollator: a systematic review of gait parameters in older persons

“…The results reveal the necessity of not only studying gait in laboratory conditions, but especially in everyday conditions. For this purpose, Cheng et al [32] suggested the use of wearable inertial sensors to determine the interaction between the rollator, the user and the walking environment.…”

Methods to Characterize the Real-World Use of Rollators Using Inertial Sensors–A Feasibility Study

“…It is worthwhile to compare the findings in this paper with our previous research [14]. In our earlier work we collected data over a number of periods of straight line walking over different surfaces.…”

“…Due to the nature of the preceding calculations, and the propensity for accelerometer data to drift, the velocity estimate must be rebased, in accordance with the authors previous work [14]. This is achieved by estimating the baseline by interpolating through the points when the velocity estimate is considered to show no movement, referred to as zero points.…”

“…The estimator stage is an evolution of previous work by the authors [14], which has been expanded significantly and proceeds in the following manner.…”

“…In our previous work [14], we reported a pilot study carried out in a simulated urban environment, showing promising predictions of both distance travelled and rollator velocity from data collected from a single inertial sensor unit located on the rollator. However, there were only two participants in the previous study (one healthy participant and one participant with multiple sclerosis) and this meant that further work was needed to validate our approach.…”