TY - JOUR
T1 - Portable Gait Lab
T2 - Estimating 3D GRF Using a Pelvis IMU in a Foot IMU Defined Frame
AU - Mohamed Refai, Mohamed Irfan
AU - van Beijnum, Bert-Jan F.
AU - Buurke, Jaap H.
AU - Veltink, Peter H.
N1 - Funding Information:
Manuscript received November 4, 2019; revised February 10, 2020 and March 10, 2020; accepted March 29, 2020. Date of publication April 20, 2020; date of current version June 5, 2020. This work was supported in part by the Perspectief Programme NeuroCIMT through the Netherlands Organisation for Scientific Research (NWO) under Grant 14905. (Corresponding author: Mohamed Irfan Mohamed Refai.) Mohamed Irfan Mohamed Refai, Bert-Jan F. van Beijnum, and Peter H. Veltink are with the Biomedical Signals and Systems, Universiteit Twente, 7522 NB Enschede, The Netherlands (e-mail: [email protected]).
Publisher Copyright:
© 2001-2011 IEEE.
PY - 2020/4/20
Y1 - 2020/4/20
N2 - Ground Reaction Forces (GRF) during gait are measured using expensive laboratory setups such as in-floor or treadmill force plates. Ambulatory measurement of GRF using wearables enables remote monitoring of gait and balance. Here, we propose using an Inertial Measurement Unit (IMU) mounted on the pelvis to estimate the GRF during gait in daily life. Calibration procedures and an Error State Extended Kalman filter (EEKF) were used to transform the accelerations at the center of mass (CoM) to the 3D GRF. The instantaneous 3D GRF was estimated for different overground walking patterns and compared with the 3D GRF measured using the reference ForceShoe™ system. Furthermore, we introduce a changing reference frame called the current step frame that followed the direction of each step made. The frame was defined using movement of the feet, and the estimated GRF were expressed in this new frame. This allowed direct comparison and validation with the reference. The mean and standard deviation of error between the estimated instantaneous 3D GRF and the reference, normalized against the range of the reference, was 12.1 ± 3.3% across all walking tasks, in the horizontal plane. The error margins show that a single pelvis IMU could be a minimal and ambulatory sensing alternative for estimating the instantaneous 3D components of GRF during overground gait.
AB - Ground Reaction Forces (GRF) during gait are measured using expensive laboratory setups such as in-floor or treadmill force plates. Ambulatory measurement of GRF using wearables enables remote monitoring of gait and balance. Here, we propose using an Inertial Measurement Unit (IMU) mounted on the pelvis to estimate the GRF during gait in daily life. Calibration procedures and an Error State Extended Kalman filter (EEKF) were used to transform the accelerations at the center of mass (CoM) to the 3D GRF. The instantaneous 3D GRF was estimated for different overground walking patterns and compared with the 3D GRF measured using the reference ForceShoe™ system. Furthermore, we introduce a changing reference frame called the current step frame that followed the direction of each step made. The frame was defined using movement of the feet, and the estimated GRF were expressed in this new frame. This allowed direct comparison and validation with the reference. The mean and standard deviation of error between the estimated instantaneous 3D GRF and the reference, normalized against the range of the reference, was 12.1 ± 3.3% across all walking tasks, in the horizontal plane. The error margins show that a single pelvis IMU could be a minimal and ambulatory sensing alternative for estimating the instantaneous 3D components of GRF during overground gait.
KW - Ambulation
KW - Ground reaction forces
KW - Inertial measurement unit
KW - Minimal sensing
KW - Gait
U2 - 10.1109/TNSRE.2020.2984809
DO - 10.1109/TNSRE.2020.2984809
M3 - Article
SN - 1534-4320
VL - 28
SP - 1308
EP - 1316
JO - IEEE transactions on neural systems and rehabilitation engineering
JF - IEEE transactions on neural systems and rehabilitation engineering
IS - 6
M1 - 9072192
ER -