Affiliation:
1. Experimental Biomechatronics Laboratory, Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, PA 15213 e-mail:
2. Experimental Biomechatronics Laboratory, Department of Mechanical Engineering & Robotics Institute, Carnegie Mellon University, Pittsburgh, PA 15213 e-mail:
Abstract
Robotic prostheses have the potential to significantly improve mobility for people with lower-limb amputation. Humans exhibit complex responses to mechanical interactions with these devices, however, and computational models are not yet able to predict such responses meaningfully. Experiments therefore play a critical role in development, but have been limited by the use of product-like prototypes, each requiring years of development and specialized for a narrow range of functions. Here we describe a robotic ankle–foot prosthesis system that enables rapid exploration of a wide range of dynamical behaviors in experiments with human subjects. This emulator comprises powerful off-board motor and control hardware, a flexible Bowden cable tether, and a lightweight instrumented prosthesis, resulting in a combination of low mass worn by the human (0.96 kg) and high mechatronic performance compared to prior platforms. Benchtop tests demonstrated closed-loop torque bandwidth of 17 Hz, peak torque of 175 Nm, and peak power of 1.0 kW. Tests with an anthropomorphic pendulum “leg” demonstrated low interference from the tether, less than 1 Nm about the hip. This combination of low worn mass, high bandwidth, high torque, and unrestricted movement makes the platform exceptionally versatile. To demonstrate suitability for human experiments, we performed preliminary tests in which a subject with unilateral transtibial amputation walked on a treadmill at 1.25 ms-1 while the prosthesis behaved in various ways. These tests revealed low torque tracking error (RMS error of 2.8 Nm) and the capacity to systematically vary work production or absorption across a broad range (from −5 to 21 J per step). These results support the use of robotic emulators during early stage assessment of proposed device functionalities and for scientific study of fundamental aspects of human–robot interaction. The design of simple, alternate end-effectors would enable studies at other joints or with additional degrees of freedom.
Subject
Physiology (medical),Biomedical Engineering
Reference69 articles.
1. Estimating the Prevalence of Limb Loss in the United States: 2005 to 2050;Arch. Phys. Med. Rehab.,2008
2. Energy-Speed Relation and Optimal Speed During Level Walking;Int. Z. Angew. Phys.,1958
3. Gait Analysis in Amputees;Am. J. Phys. Med.,1985
4. Comprehensive Analysis of Energy Storing Prosthetic Feet: Flex Foot and Seattle Foot Versus Standard Sach Foot;Arch. Phys. Med. Rehab.,1993
5. Energy Expenditure During Ambulation in Dysvascular and Traumatic Below-Knee Amputees: A Comparison of Five Prosthetic Feet;J. Rehab. Res. Dev.,1995
Cited by
106 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献