Design of a Passive, Shear-Based Rotary Hydraulic Damper for Single-Axis Prosthetic Knees

With over 30 million people worldwide in need of assistive devices, there is a great need for low-cost, high performance prosthetic technologies in the developing world. A majority of the hydraulic dampers used in prosthetic knee designs are highly specialized, expensive, require regular maintenance...

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Bibliographic Details
Main Authors: Major, Matthew J., Arelekatti, Murthy, Petelina, Nina T., Johnson, William Brett, Winter, Amos G.
Other Authors: Massachusetts Institute of Technology. Department of Mechanical Engineering
Format: Article
Published: American Society of Mechanical Engineers 2019
Online Access:http://hdl.handle.net/1721.1/120009
https://orcid.org/0000-0002-8358-7366
https://orcid.org/0000-0002-4151-0889
Description
Summary:With over 30 million people worldwide in need of assistive devices, there is a great need for low-cost, high performance prosthetic technologies in the developing world. A majority of the hydraulic dampers used in prosthetic knee designs are highly specialized, expensive, require regular maintenance, and are incompatible for use with low-cost, single-axis prosthetic knees popular in developing countries. In this study, optimal damping coefficients were computed based on a theoretical analysis of gait, specifically during the transition from the stance to swing phase of human walking when a large damping torque is needed at the knee. A novel rotary hydraulic damper prototype was designed using high-viscosity silicone oil and a concentric meshing of fins for shearing the oil. The prototype was validated experimentally to provide the desired damping torque profile. For preliminary, user-centric validation of the prototype, a gait study on one above-knee amputee in India was conducted with four different damping magnitudes. Feedback from the subject validated the optimal damping torque magnitude predicted for minimizing gait deviations and for enabling able-bodied knee kinematics. The new rotary hydraulic damper design is novel, passive, and compatible with low-cost, single-axis knee prostheses. Topics: Shear (Mechanics) , Dampers , Design , Artificial limbs , Knee