Influence of shoes and cover characteristics on the prosthetic feet Energy Storage and Release mechanism

2013 ◽  
Author(s):  
Mihaela Buzatu ◽  
Doina Bucur ◽  
Octavian Dontu ◽  
Carlo Frigo ◽  
Esteban Pavan
Keyword(s):  
Energy Storage ◽  
Release Mechanism ◽  
Prosthetic Feet

Characterizing adaptations of prosthetic feet in the frontal plane

2020 ◽  
Vol 44 (4) ◽  
pp. 225-233
Author(s):  
Michael Ernst ◽  
Björn Altenburg ◽  
Thomas Schmalz
Keyword(s):  
Energy Storage ◽  
Theoretical Model ◽  
Ankle Joint ◽  
Frontal Plane ◽  
Measured Data ◽  
Limb Amputation ◽  
Clinical Parameters ◽  
Mechanical Adaptation ◽  
Prosthetic Foot ◽  
Prosthetic Feet

Background: Energy-storage and return feet incorporate various design features including split toes. As a potential improvement, an energy-storage and return foot with a dedicated ankle joint was recently introduced allowing for easily accessible inversion/eversion movement. However, the adaptability of energy-storage and return feet to uneven ground and the effects on biomechanical and clinical parameters have not been investigated in detail. Objectives: To investigate the design-related ability of prosthetic feet to adapt to cross slopes and derive a theoretical model. Study design: Mechanical testing and characterization. Methods: Mechanical adaptation to cross slopes was investigated for six prosthetic feet measured by a motion capture system. A theoretical model linking the measured data with adaptations is proposed. Results: The type and degree of adaptation depends on the foot design, for example, stiffness, split toe or continuous carbon forefoot, and additional ankle joint. The model used shows high correlations with the measured data for all feet. Conclusions: The ability of prosthetic feet to adapt to uneven ground is design-dependent. The split-toe feet adapted better to cross slopes than those with continuous carbon forefeet. Joints enhance this further by allowing for additional inversion and eversion. The influence on biomechanical and clinical parameters should be assessed in future studies. Clinical relevance Knowing foot-specific ability to adapt to uneven ground may help in selecting an appropriate prosthetic foot for persons with a lower limb amputation. Faster and more comprehensive adaptations to uneven ground may lower the need for compensations and therefore increase user safety.

scholarly journals Energy storage and release of prosthetic feet Part 1: Biomechanical analysis related to user benefits

1997 ◽  
Vol 21 (1) ◽  
pp. 17-27 ◽  
Author(s):  
K. Postema ◽  
H. J. Hermens ◽  
J. De Vries ◽  
H. F.J.M. Koopman ◽  
W. H. Eisma
Keyword(s):  
Energy Storage ◽  
Gait Analysis ◽  
Inverse Dynamics ◽  
Mechanical Energy ◽  
Randomised Trial ◽  
Metabolic Energy ◽  
Biomechanical Analysis ◽  
Double Blind ◽  
Measuring Device ◽  
Prosthetic Feet

The energy storing and releasing behaviour of 2 energy storing feet (ESF) and 2 conventional prosthetic feet (CF) were compared (ESF: Otto Bock Dynamic Pro and Hanger Quantum; CF: Otto Bock Multi Axial and Otto Bock Lager). Ten trans-tibial amputees were selected. The study was designed as a double-blind, randomised trial. For gait analysis a VICON motion analysis system was used with 2 AMTI force platforms. A special measuring device was used for measuring energy storage and release of the foot during a simulated step. The impulses of the anteroposterior component of the ground force showed small, statistically non-significant differences (deceleration phase: 22.7–23.4 Ns; acceleration phase: 17.0–18.4 Ns). The power storage and release phases as well as the net results also showed small differences (maximum difference in net result is 0.03 J kg−1). It was estimated that these differences lead to a maximum saving of 3% of metabolic energy during walking. It was considered unlikely that the subjects would notice this difference. It was concluded that during walking differences in mechanical energy expenditure of this magnitude are probably not of clinical relevance. Ankle power, as an indicator for energy storage and release gave different results to the energy storage and release as measured with the special test device, especially during landing response. In the biomechanical model (based on inverse dynamics) used in the gait analysis the deformation of the material is not taken into consideration and hence this method of gait analysis is probably not suitable for calculation of shock absorption.

Simulation of Behaviour of an Energy Storage Device During Installation Process in Lake Ontario

2018 ◽  
Author(s):  
M. Hasanat Zaman ◽  
Ayhan Akinturk ◽  
Andrew McGillis
Keyword(s):  
Energy Storage ◽  
National Research Council ◽  
Lake Ontario ◽  
Storage Device ◽  
Release Mechanism ◽  
Storage Unit ◽  
Energy Storage Unit ◽  
Offshore Engineering ◽  
Scale Test ◽  
Good Agreement

A model of a compressed air energy storage unit is tested for tow-out and installation in the Ocean, Coastal & River Engineering (OCRE) Portfolio of the National Research Council of Canada (NRC). The proposed prototype accumulator is a cylinder of 36 m in diameter and 12 m in height, which will be installed at the bottom of Lake Ontario at about 60 m water depth. The model of the accumulator with scale 1:21.5 was fabricated at the Design and Fabrication Unit of NRC. Appropriate ballast systems were designed and applied for the tow out, installations and release mechanism tests. The model scale test was conducted to examine the hydrodynamic behavior of the accumulator during tow-out and set down operations. NRC’s Towing Tank and Offshore Engineering Basin test facilities were used for the tasks. In this paper only the installation case of the accumulator is reported and discussed. Relevant numerical simulations are also carried out. Comparisons of the numerical results with the experimental results show good agreement for the compared cases.

Manufacture of Energy Storage and Return Prosthetic Feet Using Selective Laser Sintering

2009 ◽  
Vol 132 (1) ◽  
Author(s):  
Brian J. South ◽  
Nicholas P. Fey ◽  
Gordon Bosker ◽  
Richard R. Neptune
Keyword(s):  
Energy Storage ◽  
Carbon Fiber ◽  
Selective Laser Sintering ◽  
Reaction Force ◽  
Three Dimensional ◽  
Laser Sintering ◽  
Gait Performance ◽  
Prosthetic Feet ◽  
Manufacturing Techniques ◽  
Stiffness Characteristics

Proper selection of prosthetic foot-ankle components with appropriate design characteristics is critical for successful amputee rehabilitation. Elastic energy storage and return (ESAR) feet have been developed in an effort to improve amputee gait. However, the clinical efficacy of ESAR feet has been inconsistent, which could be due to inappropriate stiffness levels prescribed for a given amputee. Although a number of studies have analyzed the effect of ESAR feet on gait performance, the relationships between the stiffness characteristics and gait performance are not well understood. A challenge to understanding these relationships is the inability of current manufacturing techniques to easily generate feet with varying stiffness levels. The objective of this study was to develop a rapid prototyping framework using selective laser sintering (SLS) for the creation of prosthetic feet that can be used as a means to quantify the influence of varying foot stiffness on transtibial amputee walking. The framework successfully duplicated the stiffness characteristics of a commercial carbon fiber ESAR foot. The feet were mechanically tested and an experimental case study was performed to verify that the locomotor characteristics of the amputee’s gait were the same when walking with the carbon fiber ESAR and SLS designs. Three-dimensional ground reaction force, kinematic, and kinetic quantities were measured while the subject walked at 1.2 m/s. The SLS foot was able to replicate the mechanical loading response and locomotor patterns of the ESAR foot within ±2 standard deviations. This validated the current framework as a means to fabricate SLS-based ESAR prosthetic feet. Future work will be directed at creating feet with a range of stiffness levels to investigate appropriate prescription criteria.

scholarly journals Stiffness and energy storage characteristics of energy storage and return prosthetic feet

2019 ◽  
Vol 43 (3) ◽  
pp. 266-275 ◽  
Author(s):  
Nicholas D Womac ◽  
Richard R Neptune ◽  
Glenn K Klute
Keyword(s):  
Mechanical Properties ◽  
Energy Storage ◽  
Graphical User Interface ◽  
Lateral Loading ◽  
Prosthetic Foot ◽  
Limb Loading ◽  
Prosthetic Feet ◽  
Force Displacement ◽  
Storage Characteristics ◽  
Graphical User Interface Tool

Background: Mechanical properties of prosthetic feet can significantly influence amputee gait, but how they vary with respect to limb loading and orientation is infrequently reported. Objective: The objective of this study is to measure stiffness and energy storage characteristics of prosthetic feet across limb loading and a range of orientations experienced in typical gait. Study design: This study included mechanical testing. Methods: Force–displacement data were collected at combinations of 15 sagittal and 5 coronal orientations and used to calculate stiffness and energy storage across prosthetic feet, stiffness categories, and heel wedge conditions. Results: Stiffness and energy storage were highly non-linear in both the sagittal and coronal planes. Across all prosthetic feet, stiffness decreased with greater heel, forefoot, medial, and lateral orientations, while energy storage increased with forefoot, medial, and lateral loading orientations. Stiffness category was proportional to stiffness and inversely proportional to energy storage. Heel wedge effects were prosthetic foot dependent. Conclusion: Orientation, manufacturer, stiffness category, and heel wedge inclusion greatly influenced stiffness and energy storage characteristics. Clinical relevance These results and an available graphical user interface tool may help improve clinical prescriptions by providing prosthetists with quantitative measures to compare prosthetic feet.

scholarly journals Analysis of Rollover Shape and Energy Storage and Return in Cantilever Beam-Type Prosthetic Feet

2014 ◽  
Author(s):  
Kathryn M. Olesnavage ◽  
Amos G. Winter
Keyword(s):  
Energy Storage ◽  
Cantilever Beam ◽  
Cross Section ◽  
Stance Phase ◽  
Center Of Pressure ◽  
Reaction Force ◽  
Heel Strike ◽  
Prosthetic Foot ◽  
Beam Type ◽  
Prosthetic Feet

This paper presents an analysis of the rollover shape and energy storage and return in a prosthetic foot made from a compliant cantilevered beam. The rollover shape of a prosthetic foot is defined as the path of the center of pressure along the bottom of the foot during stance phase of gait, from heel strike to toe off. This path is rotated into the reference frame of the ankle-knee segment of the leg, which is held fixed. In order to achieve correct limb loading and gait kinematics, it is important that a prosthetic foot both mimic the physiological rollover shape and maximize energy storage and return. The majority of prosthetic feet available on the market are cantilever beam-type feet that emulate ankle dorsiflexion through beam bending. In this study, we show analytically that a prosthetic foot consisting of a beam with constant or monotonically decreasing cross-section cannot replicate physiological rollover shape; the foot is either too stiff when the ground reaction force (GRF) acts near the ankle, or too compliant when the GRF acts near the toe. A rigid constraint is required to prevent the foot from over-deflecting. Using finite element analysis (FEA), we investigated how closely a cantilever beam with constrained maximum deflection could mimic physiological rollover shape and energy storage/return during stance phase. A constrained beam with constant cross-section is able to replicate physiological rollover shape with R2 = 0.86. The ratio of the strain energy stored and returned by the beam compared to the ideal energy storage and return is 0.504. This paper determines that there is a trade off between rollover shape and energy storage and return in cantilever beam-type prosthetic feet. The method and results presented in this paper demonstrate a useful tool in early stage prosthetic foot design that can be used to predict the rollover shape and energy storage of any type of prosthetic foot.

Progress and perspectives on halide lithium conductors for all-solid-state lithium batteries

2020 ◽  
Vol 13 (5) ◽  
pp. 1429-1461 ◽  
Author(s):  
Xiaona Li ◽  
Jianwen Liang ◽  
Xiaofei Yang ◽  
Keegan R. Adair ◽  
Changhong Wang ◽  
...  
Keyword(s):  
Energy Storage ◽  
Solid State ◽  
Lithium Batteries ◽  
Electrochemical Stability ◽  
Superionic Conductors ◽  
Fundamental Understanding ◽  
Potential Applications ◽  
Synthesis Routes

This review focuses on fundamental understanding, various synthesis routes, chemical/electrochemical stability of halide-based lithium superionic conductors, and their potential applications in energy storage as well as related challenges.

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