Academic literature on the topic 'Smart Ankle-foot prosthesis'

Physical and occupational therapists commonly provide services that incorporate prosthetic and orthotic devices such as crutches, canes, reachers, and ankle–foot orthoses to support mobility and activities of daily living (ADLs). Likewise, speech-language pathologists provide services incorporating prosthetic devices to support communication such as an electrolarynx, microcomputers, and mobile devices and apps with voice output capability. Assistive technology for cognition (ATC) includes the use of personal digital assistants (PDAs), tablets, and smart phones — cognitive prostheses — to compensate for cognitive challenges following acquired brain injury (ABI). Whereas funding sources for devices and services that support/compensate for mobility, ADLs, and communication challenges are generally well established, funding for ATC devices and services is relatively new to the field of speech-language pathology. This article explores the funding aspect of ATC devices and services.

abstract: Locomotion is of prime importance in enabling human beings to effectively respond in space and time to meet different needs. Approximately 2 million Americans live with an amputation with most of those amputations being of the lower limbs. To advance current state-of-the-art lower limb prosthetic devices, it is necessary to adapt performance at a level of intelligence seen in human walking. As such, this thesis focuses on the mechanisms involved during human walking, while transitioning from rigid to compliant surfaces such as from pavement to sand, grass or granular media. Utilizing a unique tool, the Variable Stiffness Treadmill (VST), as the platform for human walking, rigid to compliant surface transitions are simulated. The analysis of muscular activation during the transition from rigid to different compliant surfaces reveals specific anticipatory muscle activation that precedes stepping on a compliant surface. There is also an indication of varying responses for different surface stiffness levels. This response is observed across subjects. Results obtained are novel and useful in establishing a framework for implementing control algorithm parameters to improve powered ankle prosthesis. With this, it is possible for the prosthesis to adapt to a new surface and therefore resulting in a more robust smart powered lower limb prosthesis.
Dissertation/Thesis
Masters Thesis Biomedical Engineering 2019

The key goal of prosthetic foot design is to mimic the function of the lost limb. A passive spring and damper system can imitate the behavior of an ankle for low level activity, e.g. walking at slow to normal speeds and relatively gentle ascents/descents. In light of this, a variety of constant stiffness prosthetic feet are available on the market that serve their users well. However, when walking at a faster pace and ascending/descending stairs, the function of the physiological ankle is more complex and the muscular activity contributes to the stride in different ways. One of the challenges in prosthetic device design is to achieve the appropriate range of stiffness of the arrangement of joints and spring elements for different tasks, as well as varying loading of the prosthetic device. This calls for an adaptive mechanism that mimics the stiffness characteristics of a physiological foot by applying real-time adaptive control that changes the stiffness reactively according to user’s needs. The goal of this paper is to define the stiffness characteristics of such a device through modeling. The research is based on a finite element model of a well-received prosthetic foot design, which is validated by mechanical measurements of the actual product. We further enhance the model to include a secondary spring/dampener element. Various smart material technologies are considered in the design to provide control of flexibility and damping rate of the ankle joint movement. The reactive control of the secondary element allows the simulated prosthetic foot to adapt the ankle joint to imitate the behavior of the physiological ankle during different activities and in different phases of the gait cycle.

The applicability of variable modulus fluidic flexible matrix composites (F2MC) is investigated for development of prosthetic devices. The F2MC material is an innovative combination of high performance composite tubes containing high bulk modulus fluids. The new material system can potentially achieve several orders of magnitude change in stiffness through valve control. The F2MC material system is investigated in this research through analytical studies for active impedance control for load transfer reduction in a transtibial prosthetic sockets and impedance joint control for an ankle-foot orthoses (AFO). Preliminary analysis results indicate that the variable modulus system can reduce the load transfer between the limb and transtibial socket and can provide impedance tailoring for improving foot-slap in an AFO.