title: Accuracy of a Wearable Sensor for Measures of Head Kinematics and Calculation of Brain Tissue Strain.
abstract: Wearable kinematic sensors can be used to study head injury biomechanics based on kinematics and, more recently, based on tissue strain metrics using kinematics-driven brain models. These sensors require in-situ calibration and there is currently no data conveying wearable ability to estimate tissue strain. We simulated head impact (n = 871) to a 50th percentile Hybrid III (H-III) head wearing a hockey helmet instrumented with wearable GForceTracker (GFT) sensors measuring linear acceleration and angular velocity. A GFT was also fixed within the H-III head to establish a lower boundary on systematic errors. We quantified GFT errors relative to H-III measures based on peak kinematics and cumulative strain damage measure (CSDM). The smallest mean errors were 12% (peak resultant linear acceleration) and 15% (peak resultant angular velocity) for the GFT within the H-III. Errors for GFTs on the helmet were on average 54% (peak resultant linear acceleration) and 21% (peak resultant angular velocity). On average, the GFT inside the helmet overestimated CSDM by 0.15.
authors.affiliation: 1 University of Alberta.
authors.forename: Brooklynn M
authors.initials: BM
authors.lastname: Knowles
authors.affiliation: 1 University of Alberta.
authors.forename: Henry
authors.initials: H
authors.lastname: Yu
authors.affiliation: 1 University of Alberta.
authors.forename: Christopher R
authors.initials: CR
authors.lastname: Dennison
mesh_terms: D000054:Acceleration; D061725:Accelerometry / Q000295:instrumentation*; D001921:Brain / Q000502:physiology*; D055119:Elastic Modulus / Q000502:physiology; D004867:Equipment Design; D019544:Equipment Failure Analysis; D019416:Head Movements / Q000502:physiology*; D006260:Head Protective Devices; D006801:Humans; D018670:Monitoring, Ambulatory / Q000295:instrumentation*; D010812:Physical Stimulation / Q000295:instrumentation / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013314:Stress, Mechanical
keywords: head injury; helmet; injury biomechanics; wearable sensors