P.46 Magneto-inertial wearable device: Upper limb trajectory identification in non-ambulant patients with spinal muscular atrophy

Abstract

Precise upper limb function quantification is challenging but essential to judge efficacy of treatments for patients living with neuromuscular disorders. Lack of robust motor function endpoint can limit the conduct of clinical trials in this population and thus the access to innovative medication. The need for improving current outcomes and exploring innovative approaches, like wearable devices or video-based home assessment is consensual in the community. Recently, reachable workspace measured in a controlled environment has been proposed as a sensitive outcome in FSHD. We previously demonstrated that upper limb movement of non-ambulant patients can be reliably quantified using magneto-inertial sensors in non-controlled environment and constitutes a sensitive outcome in spinal muscular atrophy (SMA), using basic variable, such as the norm of the gyrometers, or more elaborated variables such as the power developed by the upper limb. To combine the clinical meaningfulness of reachable workspace and the potential of magneto-inertial technology, we investigated in non-ambulant patients with SMA how reachable workspace can be quantified in real life environment using a magneto-inertial sensor worn at the wrist. We first elaborated a model of upper limb dynamic for patients in the wheelchair, and we validated our hypothesis in a controlled environment by reconstructing the reachable workspace using high precision motion capture system and magneto inertial technology. In a second step, we compared the continuous measure of the reachable workspace in non-controlled environment with previously published digital outcomes for the upper limb in non-ambulant patients with SMA. We will present the modelling of reachable workspace and the results of this comparison.