Towards a Wearable Wheelchair Monitor: Classification of Push Style Based on Inertial Sensors at Multiple Upper Limb Locations

Abstract

Measuring manual wheelchair activity by using wearable sensors is on the rise for rehabilitation and monitoring purposes. Stroke pattern is an important descriptor of the wheelchair user's quality of movement. This paper evaluates the capability of inertial sensors located at different upper limb locations plus wheel, to classify two types of stroke pattern for manual wheelchairs: semicircle and arc. Data was collected using bespoke inertial sensors with a wheelchair fixed to a treadmill. Classification was done with a linear SVM algorithm, and classification performance was computed for each sensor location in the upper limb, and then in combination with wheel sensor. For single sensors, forearm location had the highest accuracy (96%) followed by hand (93%) and arm (90%). For combined sensor location with wheel, best accuracy came in combination with forearm. These results set the direction towards a wearable wheelchair monitor that can offer multiple on-body locations for increased usability.

Effect of Context-Dependent Modulation of Trunk Muscle Activity on Manual Wheelchair Propulsion

“…The interaction of stroke pattern on inertia sensor accuracy during MWC propulsion is an emerging field of study, but a recent report showed the greatest accuracy when a forearm sensor was combined with a wheel sensor. 18 Manual wheelchair users will need to provide feedback on the amount of instrumentation that they are willing to wear and the minimum level of accuracy that is acceptable for real-life, home-use, propulsion assistance neuroprostheses.…”

“…Accelerometers or inertial measurement units (IMUs) have been used to identify wheelchair propulsion activities and distinguish whether wheelchair users are propelling themselves or being pushed by an attendant, 15,16 discriminate between the most common push styles, 15,17,18 and separate minimal wheelchair movements from everyday tasks. 19,20 Generally, wheel-mounted…”