Development of a Six-Axis Force/Moment Sensor Attached to a Prosthetic Limb for the Unrestrained Gait Measurement

Since the number of trans-femoral amputees has increased by industrial or traffic accidents in modern society, the demand for a prosthetic limb has also increased year after year. In this case, those amputees must regain moving pattern by refined efficient gait training using load conditions on a prosthetic limb as quantitative evaluation indices. However, conventional prosthetic gait training systems cannot measure long continuous walking motions under a wide range of environmental conditions. In this paper, a novel six-axis force/moment sensor, which is attached to a prosthetic limb for the unrestrained gait measurement, is developed. As a result of applying structural optimization techniques using response surface method and desirability function to this sensor by finite element analysis, optimum design variables to make the effect of interference components much smaller are obtained. Finally, characteristics test using the production model by applying optimum design variables is performed and the effectiveness of the developed sensor is validated.