Control and Evaluation of a Powered Transfemoral Prosthesis for Stair Ascent

• Published in: IEEE transactions on neural systems and rehabilitation engineering Vol. 25; no. 7; pp. 917 - 924
• Main Authors: Ledoux, Elissa D., Goldfarb, Michael
• Format: Journal Article
• Language: English
• Published: United States IEEE 01.07.2017
• Subjects: amputees; Artificial Limbs; Electric Power Supplies; Equipment Design; Equipment Failure Analysis; Exoskeleton Device; Feedback; Female; Foot; Gait; Humans; Knee; Leg - physiopathology; Leg - surgery; Legged locomotion; Male; metabolics; Middle Aged; Oxygen Consumption; Pilot Projects; Powered prosthetics; Prosthetics; Protocols; Reproducibility of Results; Robotics - instrumentation; Robotics - methods; Sensitivity and Specificity; stair ascent; Steady-state; Torque; transfemoral prosthesis; Treatment Outcome; unsteady-state
• ISSN: 1534-4320; 1558-0210
• DOI: 10.1109/TNSRE.2017.2656467

This paper assesses the metabolic effort exerted by three transfemoral amputees, when using a powered knee and ankle prosthesis for stair ascent, relative to ascending stairs with passive knee and ankle prostheses. The paper describes a controller that provides step-over stair ascent behavior reflective of healthy stair ascent biomechanics, and describes its implementation in a powered prosthesis prototype. Stair ascent experiments were performed with three unilateral transfemoral amputee subjects, comparing the oxygen consumption required to ascend stairs using the powered prosthesis (with a step-over gait), relative to using their daily-use energetically passive prostheses (with a step-to gait). Results indicate on average a 24% reduction in oxygen consumption and a 30% reduction in stair ascent timewhen using the powered prosthesis, relative to when using the passive prostheses. All subjects expressed a strong preference for ascending stairs using the powered prosthesis.