Inertial sensor based method for identifying spherical joint center of rotation.
The miniaturized wireless inertial measurement unit (IMU) technology and algorithms presented herein promote rapid and accurate predictions of the center-of-rotation (CoR) for ball/spherical joints. The algorithm improves upon existing IMU-based methods by directly utilizing the measured acceleration and angular velocity provided by the IMU to deduce the CoR in lieu of relying on error-prone velocity and position estimates. Results demonstrate that this new method resolves the position of the CoR to within a 3mm sphere of the true CoR determined by a precision coordinate measuring machine. Such accuracy may render this method attractive for broad use in field, laboratory and clinical settings requiring non-invasive and rapid estimates of joint CoR.
Mechanical Engineering, University of Michigan, 2350 Hayward Street, Ann Arbor, MI 48109-2125, USA. Electronic address: ryanmcg@umich.edu.
Ryan S
RS
McGinnis
Noel C
NC
Perkins
D000054:Acceleration; D000465:Algorithms; D005269:Femur / Q000502:physiology*; D006621:Hip Joint / Q000502:physiology*; D006801:Humans; D012399:Rotation; D059015:Wireless Technology
Biomechanics; Hip arthroplasty; Inertial measurement unit; Inverse dynamic modeling; Joint center-of-rotation; Knee arthroplasty