RehabMove 2018: CAPTURING PHYSICAL PERFORMANCE IN DAILY WHEELCHAIR MOBILITY: WHAT 'REAL LIFE DATA' TO MEASURE?

PURPOSE: For longitudinal studies of persons with spinal cord injury (SCI) in interaction with their actual environment, Real Life Data (RLD) on Physical Performance (PP) is desired. This case study evaluates options to capture PP in daily wheelchair mobility. Wearable sensors enable the collection of RLD, but new methods, algorithms and additional information might be required to link to existing knowledge. METHODS: One experienced participant in a manual wheelchair followed two distinct routes (standard or wheelchair-friendly) at the Swiss Paraplegic Center, from halfway to top of the campus hill. An instrumented wheelchair (SmartWheel, Out-Front, USA) measured wheel angle, forces and torques at the rim. An inertial sensor (IMU, Movea Inc., France) was fixed and aligned to wheelchair frame, trunk and wrist. GPS location was recorded with a smartphone. For comparison of the two routes, the following variables were measured or derived: Track Descriptives (TD); distance, speed, acceleration, inclination, altitude gain, and PP; force and torque exerted on the rim, power output (PO). RESULTS: Data processing is ongoing at time of abstract deadline. Results will be presented in a cross table showing the distinct data sources versus respective derived variables like TD and PP for the two routes. (PRELIMINARY) DISCUSSION: Considering TD, the resolution of generic GPS signals and online mapping tools like Google Maps is not adequate. Additional detailed geographical models can increase this resolution. The use of an accelerometer to calculate distance, speed and PO is prone to error and heavily depending on filter characteristics. The use of a simple rotary encoder on the wheel axis will increase the resolution and accuracy of most TD considerably. CONCLUSION: Current wearable technology is promising in capturing daily mobility, but it is advised to use smart combinations of data sources. Additional environmental detail might increase resolution and accuracy of PP and TD