TY - JOUR

T1 - Realtime assessment of foot orientation by Accelerometers and Gyroscopes

AU - Seel, Thomas

AU - Graurock, David

AU - Schauer, Thomas

N1 - Funding Information: Being conducted in the research project BeMobil, this work is funded by the German Federal Ministry of Research and Education (FKZ 16SV7069K).

PY - 2015

Y1 - 2015

N2 - Foot orientation can be assessed in realtime by means of a foot-mounted inertial sensor. We consider a method that uses only accelerometer and gyroscope readings to calculate the foot pitch and roll angle, i.e. the foot orientation angle in the sagittal and frontal plane, respectively. Since magnetometers are avoided completely, the method can be used indoors as well as in the proximity of ferromagnetic material and magnetic disturbances. Furthermore, we allow for almost arbitrary mounting orientation in the sense that we only assume one of the local IMU coordinate axes to lie in the sagittal plane of the foot. The method is validated with respect to a conventional optical motion capture system in trials with transfemoral amputees walking with shoes and healthy subjects walking barefoot, both at different velocities. Root mean square deviations of less than 4° are found in all scenarios, while values near 2° are found in slow shoe walking. This demonstrates that the proposed method is suitable for realtime application such as the control of FES-based gait neuroprostheses and active orthoses.

AB - Foot orientation can be assessed in realtime by means of a foot-mounted inertial sensor. We consider a method that uses only accelerometer and gyroscope readings to calculate the foot pitch and roll angle, i.e. the foot orientation angle in the sagittal and frontal plane, respectively. Since magnetometers are avoided completely, the method can be used indoors as well as in the proximity of ferromagnetic material and magnetic disturbances. Furthermore, we allow for almost arbitrary mounting orientation in the sense that we only assume one of the local IMU coordinate axes to lie in the sagittal plane of the foot. The method is validated with respect to a conventional optical motion capture system in trials with transfemoral amputees walking with shoes and healthy subjects walking barefoot, both at different velocities. Root mean square deviations of less than 4° are found in all scenarios, while values near 2° are found in slow shoe walking. This demonstrates that the proposed method is suitable for realtime application such as the control of FES-based gait neuroprostheses and active orthoses.

KW - Accelerometers, Gyroscopes

KW - Biomedical Engineering

KW - Foot Orientation

KW - Inertial Measurement Unit

KW - Realtime Motion Assessment

KW - Rehabilitation Engineering

UR - http://www.scopus.com/inward/record.url?scp=84994501105&partnerID=8YFLogxK

U2 - 10.1515/cdbme-2015-0112

DO - 10.1515/cdbme-2015-0112

M3 - Article

AN - SCOPUS:84994501105

VL - 1

SP - 466

EP - 469

JO - Current Directions in Biomedical Engineering

JF - Current Directions in Biomedical Engineering

IS - 1

ER -