Download or read book Towards Personalized Powered Ankle foot Prostheses written by Jonathan Realmuto and published by . This book was released on 2017 with total page 243 pages. Available in PDF, EPUB and Kindle. Book excerpt: This research aims to develop a personalized powered ankle-foot prosthesis. Unilateral below-knee amputees generally have walking gait patterns with temporal, kinematic, and kinetic asymmetries resulting from neuromuscular adaptations required to compensate for the lack of ankle function leading to a host of secondary musculoskeletal impairments. Powered ankle-foot prostheses can restore some ankle function by active compensation at the prosthetic joint. However, current methods are limited by: (i) reliance on able-bodied gait data for trajectory synthesis, (ii) expert tuning of subject specific parameters, (iii) an inability to adapt with the user in the long term, and (iv) a limited amount of mechanical personalization. This work seeks to directly address the first two limitations with a symmetry learning controller that automatically tunes control trajectories by iteratively adjusting the prosthetic ankle torque to match the intact ankle torque in the frequency domain. The challenge is to avoid divergence caused by the time-vary human-robot dynamics. Towards this, a rule based iterative learning algorithm is introduced that adjusts the frequency dependent learning rate based on the changes in error. The symmetry controller could conceivably be adapted for indefinite use e.g., by caching, storing, and rewriting training instances, and thus address the third limitation. To reducing the active requirement of the device, a nonlinear cam-based spring that can be customized to the user and/or activity is introduced, which provides some level of passive personalization (the fourth limitation). The new method enables symmetric ankle moment control and is tailored to the individual. The method was implemented and experimentally verified. Results indicated that symmetry of the ankle moment was significantly increased and unbounded growth of the control signal was avoided.

Download or read book Adaptive Symmetry Learning and Data driven Predictive Models for Personalized Control of Robotic Ankle foot Prostheses written by Christopher Thomas Prasanna and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The main goal of this research is to develop a personalized and adaptive control scheme for powered ankle-foot prostheses. Individuals with below-knee amputation generally have gait patterns that are more asymmetrical about their two limbs when compared to the general population. This is likely due to a lack of proper prosthetic ankle function. It has been observed that these individuals compensate for this lack of mobility in ways that can lead to a host of long-term musculoskeletal impairments (e.g., osteoarthritis in the knee and hip of the intact limb). Powered prostheses have the ability to better emulate biological ankles since they are capable of generating power, unlike clinically-prescribed limbs that are completely passive and can only return stored energy. However, current powered prosthesis control methods are over-reliant on able-bodied data, require extensive amounts of tuning by experts, and cannot adapt to the user's unique gait patterns. This work directly addresses all the listed limitations with an adaptive and data-driven control strategy. The controller utilizes time-invariant control signals enabled by phase-based state estimation, an impedance-based feedback loop, and trajectory planning that iteratively adjusts the motion of the prosthetic ankle to match the intact ankle motion. This robotic ankle controller was experimentally evaluated on two individuals with below-knee amputation. The control scheme successfully increased ankle angle symmetry about the two limbs, significantly increased peak prosthetic ankle power output at push-off, and significantly reduced factors associated with osteoarthritis in the intact limb. In addition, control signals were bounded, personalized, and unique across subjects without the use of able-bodied data or extensive tuning. This research also applied deep learning to build models capable of accurately predicting prosthetic ankle torque values from inverse dynamics. Computing inverse dynamics is a time-intensive task, is limited to a laboratory setting, and requires a large array of motion capture markers. The models developed in this research enable total prosthetic ankle torque from inverse dynamics to be observed using signals only from common wearable sensors. This application of machine learning provides an avenue to the development of model-based control systems for powered limbs aimed at optimizing prosthetic ankle torque.

Download or read book Advances for Prosthetic Technology written by Robert LeMoyne and published by Springer. This book was released on 2016-03-10 with total page 145 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses on the advances in transtibial prosthetic technology and targets research in the evolution of the powered prosthesis such as the BiOM, which was derived from considerable research and development at the Massachusetts Institute of Technology. The concept of the book spans the historical evolution of prosthetic applications from passive to new and futuristic robotic prosthetic technologies. The author describes the reasons for amputation, surgical procedures, and an historical perspective of the prosthesis for the lower limb. He also addresses the phases and sub-phases of gait and compensatory mechanisms arising for a transtibial prosthesis and links the compensatory mechanisms to long-term morbidities. The general technologies for gait analysis central to prosthetic design and the inherent biomechanics foundations for analysis are also explored. The book reports on recent-past to current-term applications with passive elastic prostheses. The core of the book deals with futuristic robotic prostheses including their function and major subsystems, such as actuator technology, state machine control, and machine learning applications. Finally, the envisioned future trends in the prosthetic technology space are presented.

Download or read book A Neuromuscular model Based Control Strategy for Powered Ankle foot Prostheses written by Michael Frederick Eilenberg and published by . This book was released on 2009 with total page 90 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the development of a powered ankle-foot prosthesis, it is desirable to provide the prosthesis with the ability to exhibit human-like dynamics. A simple method for achieving this goal involves trajectory tracking, where a specific target torque trajectory is known, and the controller issues commands to follow the trajectory as closely as possible. However, without a methodology to update the desired trajectory in real time, this type of control scheme is limited in that it cannot adapt to externally-applied disturbances. Adaptation is critical in the field of prosthetics. A prosthesis must be able to adjust to variable terrain and respond to changes in behavior of the wearer. In this thesis, we hypothesize that a powered ankle-foot prosthesis that is controlled using a positive-force- feedback reflex of a Hill-type posterior leg muscle will exhibit biologically-consistent adaptive changes in stance phase behavior across terrain. To evaluate this hypothesis, a controller for a powered ankle-foot prosthesis is advanced that comprises a neuromuscular model consisting of a single, effective plantar flexor muscle with positive force feedback and an effective dorsiflexor consisting of a proportional-derivative impedance controller. Selected parameters of this hybrid controller were optimized to best match the torque-angle relationship of an intact, biological ankle from a weight and height-matched individual with intact limbs. The torque-tracking capabilities of the electromechanical system were evaluated, and a control system was developed to enable the prosthesis to produce human-like ankle mechanics. Clinical trials were performed on a healthy, bilateral amputee study participant at two separate level-ground walking speeds, as well as for ramp ascent and descent walking at self-selected speeds. The neuromuscular reflex model, when used as the basis of the prosthetic controller during these trials, produced ankle torques in qualitative agreement with values from the weight and height-matched individual with intact limbs. This agreement included an impedance modulation in the initial stance period, as well as a biologically consistent trend of increasing prosthesis net work for correspondingly increasing floor inclinations.

Download or read book Design and Control of a Two Degree of Freedom Powered Ankle foot Prosthesis written by Tsung-Han Hsieh (S.M.) and published by . This book was released on 2019 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt: Powered ankle prostheses have been proven to improve the walking economy of transtibial amputees although these powered systems are usually much heavier in weight than conventional prostheses. All commercial powered ankle prostheses that are currently available can only perform one-degree-of-freedom motion in a limited range. However, the human ankle can perform both frontal and sagittal plane motions. Studies have shown that the frontal plane motion during ambulation is associated with balancing. As more advanced neural interfaces have become available for amputees, it is possible to fully recover ankle function by combining neural signals and a robotic ankle. Accordingly, there is a need for a powered ankle prosthesis that can have active control on not only plantarflexion and dorsiflexion but also eversion and inversion. The objective of this thesis is to design and evaluate a two-degree-of-freedom powered ankle-foot prosthesis that is untethered and can support an average size human for level-ground walking with full power. At present, a system with such capabilities only exists as tethered. The prosthesis presented in this thesis is a second-iteration design based on its predecessor. The new design features a larger joint range of motion, a more robust transmission, and a more powerful battery module. Benchtop tests and walking trials were conducted to evaluate the system. The results demonstrate system characteristics and dynamics and the ability to support body weight in level-ground walking.

Download or read book Powered Ankle foot Prosthesis for the Improvement of Amputee Walking Economy written by Samuel Kwok-Wai Au and published by . This book was released on 2007 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt: The human ankle provides a significant amount of net positive work during the stance period of walking, especially at moderate to fast walking speeds. On the contrary, conventional ankle-foot prostheses are completely passive during stance, and consequently, cannot provide net positive work. Clinical studies indicate that transtibial amputees using conventional prostheses exhibit higher gait metabolic rates as compared to intact individuals. Researchers believe the main cause for the observed increase in metabolism is due to the inability of conventional prostheses to provide net positive work at terminal stance in walking. This objective of this thesis is to evaluate the hypothesis that a powered ankle-foot prosthesis, capable of providing active mechanical power at terminal stance, can improve amputee metabolic walking economy compared to a conventional passive-elastic prosthesis. To test the hypothesis, a powered prosthesis is designed and built that comprises a unidirectional spring, configured in parallel with a force-controllable actuator with series elasticity. The prosthesis is controlled to mimic human ankle walking behavior, in particular, the power generation characteristics observed in normal human walking. The rate of oxygen consumption is measured as a determinant of metabolic rate on three unilateral transtibial amputees walking at self-selected speeds. The initial clinical evaluation shows that the powered prosthesis improves amputee metabolic economy from 7% to 20% compared to the conventional passive-elastic prostheses (Flex-Foot Ceterus and Freedom Innovations Sierra), even though the powered system is twofold heavier than the conventional devices. These results support the proposed hypothesis and also suggest a promising direction for further advancement of ankle-foot prosthesis.

Download or read book CONTROL OF A POWERED ANKLE FOOT PROSTHESIS written by and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract : Active ankle prostheses controllers are demonstrating gaining smart features to improve the safety and comfort offor users. The perception of user intention to modulate the ankle dynamics is a well-known example of such feature. But not much work focused on the perception of the environment, nor how the environment should be included in the mechanical design and control of the prosthesisprostheses. The proposed work aims to improve the feasibility of integrate the environment perception integration intoto the prostheses controllersler, and to define the desired ankle dynamics, as mechanical impedance, duringof the human walk on different environmental settings. As a preliminary work on environment perception, a vision system was developed that can estimate the ground profileslope and height. The desired prosthesis impedance dynamics is was defined as the dynamics mechanical impedance of a healthy ankle; , therefore,which required the a system identification methodof the human ankle was developed. Simulations showed the inertia parameters of a rigid bodymockup foot can be estimated. Further experiments will show the accuracy of environment perception and of the impedance estimation.

Download or read book Powered Prostheses written by Houman Dallali and published by Academic Press. This book was released on 2020-04-17 with total page 282 pages. Available in PDF, EPUB and Kindle. Book excerpt: Powered Prostheses: Design, Control, and Clinical Applications presents the state-of-the-art in design, control and application of assistive technologies used in rehabilitation, including powered prostheses used in lower and upper extremity amputees and orthosis used in the rehabilitation of various joint disorders. The progress made in this field over the last decade is so vast that any new researcher in this field will have to spend years digesting the main achievements and challenges that remain. This book provides a comprehensive vision of advances, along with the challenges that remain on the path to the development of true bionic technology. - Describes the latest assistive technologies that can help individuals deal with joint pain or limb loss - Presents a tangible and intuitive description of scientific achievements made - Highlights the existing technologies and devices that are available and used by amputees or patients with mobility limitations - Suggests solutions and new results that can further enhance assistive technologies

Download or read book Computational Design Methods for Compliant Robotic Ankle Prostheses written by Tyler Morrison and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: There is substantial research interest in developing prostheses for amputated lower limbs that allow amputees to move dynamically with the same ease as non-amputee persons. Recent developments in this field involve robotic powered ankle prostheses. In contrast to conventional and energy storing prostheses, robotic powered ankle prostheses include actuators and controllers and can produce positive net work. Despite proposing a number of promising candidates for the design of such devices, researchers have largely struggles to realize their theoretical potential. Despite the years of engineering and iteration invested in each prototype design, at the end of the design process, human subject testing routinely reveals that amputees do not benefit from the device as predicted. The effort required for an amputee to walk with a powered ankle prostheses usually fails to improve relative to non-amputee walking or amputee walking with simpler energy storage devices. Additionally, the physical and psychological comfort of novel designs often fail to show progress from the status quo. In this work, we attempt to contribute improvements to the design process for robotic powered prosthetic ankle devices by developing novel computational design methods and tools principally aimed at the design of compliant linkages. A new kinetostatic synthesis problem for a general compliant four-bar linkage is proposed as a min-max problem. The method is data-driven and can be used to design personalized devices. It can also fuse data sources across walking speeds, subjects, or other motions, to design a single device to accommodate a variety of motions. A new gait predictive simulation problem is proposed. For the first time, computational gait prediction is demonstrated for the human-robot hybrid system that includes detailed dynamic models of robotic prostheses. These models include closed-loop linkages for transmission, compliant elements, and internal actuator dynamics. The relevant existing tools for solving gait prediction problems are identified and augmented so as to permit solutions to the novel problem. An example design process demonstrates the utility of the prediction tool for design. Finally, a parametric study method based on the previously defined and developed gait prediction problem is detailed. The method addresses the challenge of producing robust gait solutions suitable for parametric optimization by proposing an iterative process of using the optimal trajectories of parametrically similar designs from the previous iteration to start the subsequent solution attempt iteration. Design studies show how the method can be applied to study and perhaps augment existing, proposed designs of powered ankles in the literature. These computational design tools and methods may permit faster iteration on prosthetic device designs, and may reveal non-intuitive results without the time and resource costs of large-scale human subject studies.

Download or read book Design and Development of Mechanical Metatarsophalangeal Joint for Powered Ankle foot Prostheses written by Jasmin Elena Palmer and published by . This book was released on 2019 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis seeks to explore passive designs for a mechanical alternative to the metatarsophalangeal (MTP) joint, a critical anatomical component in human feet which allows for various types of anatomical motion. Our goal is to design a system that will act as a platform to test a proof of concept for a passive ankle-foot prosthesis with an MTP joint, but can also be adapted to use an actuated joint in the future. To increase the user's range of motion, our aim was for the mechanical MTP joint to achieve a maximum 600 dorsiflexion angle. We developed 2 MTP joint designs (Rubber Hinge and Fabric Hinge) with 2 body geometries varying at the heel for each (Traditional Heel and Inverted Heel) for a total of 4 models. We performed a static load Finite Element Analysis (FEA) using the Solidworks FEA Simulation Tool. The FEA was performed under the worst-case static load scenarios for the toe and body components of the prosthesis, standing on tiptoe with a dorsiflexion angle of 60' for the toe components and standing with all weight on the heel for the body components. The simulation yielded that not only did no components experience any irreversible deformation, but that the Rubber Hinge design had a minimum safety factor of 5.7, 10, and 4.5 for the Toe, Inverted Heel Body, and Traditional Heel Body respectively and the Fabric Hinge Design had a minimum safety factor 1.4, 9.9 and 4.5 for the Toe, Inverted Heel Body, and Traditional Heel Body respectively. This informed us that though both designs did not undergo failure under the prescribed loads, material utilization was in excess and could be further optimized to decrease the weight. Future designers should focus on implementing this platform into high fidelity physical models to be tested under various static and dynamic loading conditions as well as further optimizing the dimensions of the prosthesis.

Download or read book Development and Application of Semi active Prosthetic Foot ankle Systems written by Kieran Kieran Nichols and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: There is a need for improved design and function of prosthetic devices to aid walking in persons with transtibial amputations. This dissertation focused on two semi-active ankle-foot prosthetic devices, the Variable Stiffness Foot (VSF) and Two Axis aDaptable Ankle (TADA), which allow users to change biomechanical ankle-foot functions using simpler designs, lower costs, and less power than active prostheses. The background for this dissertation explored the main lower-limb biomechanical principles of prosthetic design, prosthetic-walking mechanics, and sensor feedback. The VSF manuscript investigated the mechanical impact of adjusting stiffness on lower limb mechanics using a prosthetic foot, which can modulate forefoot stiffness. A less stiff VSF resulted in increased ankle dorsiflexion angle, decreased ankle plantarflexor moment, decreased knee extension, decreased knee flexor moment, and increased magnitudes of prosthetic energy storage, energy return, and push-off power. These findings suggest that a less stiff VSF may offer advantages in lower joint moments and greater ankle angle range of motion for individuals with lower-limb prostheses. The Two Axis aDaptable Ankle (TADA) is a semi-active prosthetic ankle that offers independent modulation of sagittal and frontal ankle angles. The first TADA study modified a Raspberry Pi 4 for real-time control of brushless direct-current motors, allowing for precise and reliable ankle angle adjustments. The control system employed CANopen over EtherCAT (CoE) for synchronized communication between the Raspberry Pi and motor controllers. The results demonstrated improved movement times, lower movement errors, and higher data transmission rates. As a continuation, the final TADA study aimed to create an ankle prosthesis that can synchronously record lower-body kinematics and kinetics and assess the sensitivity of those mechanics to different walking speeds and ankle angles for an unimpaired participant. Using a pylon load cell, the results showed that peak magnitudes and impulses increased for plantarflexor moments with increased plantarflexion angle and for evertor moments with increased inversion angles. Moreover, the peak sagittal pylon moments increased with higher walking speeds. The integrated control system of the TADA effectively controls ankle angles, can affect lower-body mechanical outcomes, and can allow for efficient adaptation to various speeds and terrains in users with transtibial amputations.

Download or read book Anticipatory Muscle Responses for Transitioning Between Rigid Surface and Surfaces of Different Compliance written by Ruby Afriyie Obeng and published by . This book was released on 2019 with total page 65 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Advances in Mechatronics and Biomechanics towards Efficient Robot Actuation written by Jörn Malzahn and published by Frontiers Media SA. This book was released on 2019-06-28 with total page 195 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Estimation of Ground Reaction Force and Zero Moment Point on a Powered Ankle foot Prosthesis written by Ernesto Carlos Martinez Villalpando and published by . This book was released on 2006 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt: (Cont.) Moreover, this sensory information is sufficient to closely estimate the ZMP location during the single support phase of slow walking and while standing on one leg. This research contributes to the development of fully integrated artificial extremities that mimic the behavior of the human ankle-foot complex, especially to help improve the postural stability of lower extremity amputees.

Download or read book Active Above Knee Prosthesis written by Zlata Jelacic and published by Academic Press. This book was released on 2020-06-16 with total page 291 pages. Available in PDF, EPUB and Kindle. Book excerpt: Active Above-Knee Prosthesis: A Guide to a Smart Prosthetic Leg presents original research and development results, providing a firsthand overview of idea generation and prototype production. The book gives insights into the problem of stair ascent for people with above-knee amputation and offers a solution in the form of a physical prototype of an active above-knee prosthesis with an actuated ankle. The book's authors have developed and tested a physical prototype of an active above-knee prosthesis, giving anyone who is researching and designing prosthetic devices firsthand knowledge on how to build on, and continue with, work that has already been done. - Presents state-of-the-art technology in powered prosthetics - Helps readers evaluate design options and create new developments - Provides guidance on the evolution of advanced prosthetic design

Download or read book Design and Mechanical Validation of Commercially Viable Personalized Passive Prosthetic Feet written by Charlotte Méry Folinus and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis aims to understand how a personalized, affordable prothetic foot can be realized for a clinical-commercial setting. First, we evaluate stakeholder needs and identify the flows of products, capital, and services between prosthetics suppliers, distributors, prosthetists, amputees, and insurance providers. We elucidate the design requirements for a personalized prosthetic foot that can be manufactured, distributed, and clinically provided by Hanger, a current leader in both product distribution and patient care in orthotics and prosthetics.

Download or read book Biomechanics of Lower Limb Prosthetics written by Mark R. Pitkin and published by Springer. This book was released on 2009-10-14 with total page 153 pages. Available in PDF, EPUB and Kindle. Book excerpt: Foreword from a Clinical Biomechanist, Applied Physiologist and Prosthetist teaching graduate students in Prosthetics & Orthotics. While there are many books on Biomechanics, arguably the quintessential science of limb prosthetics, none addresses the fundamental principles in sufficient detail and depth to be practically useful to the prosthetist, rehabilitation specialist or researcher. Dr. Pitkin’s monograph is an exemplary collection of theoretical principles from his research and o- ers, presented in its clinical and applied biomechanics form. The textbook provides an excellent overview of the many facets of lower limb prosthetic design and engineering for the ardent clinician researcher and student. The book delves into many of the basic concepts that are required knowledge for the clinician and the scientist to have as the foundation for their work. Dr. Pitkin has an e- quent manner in which he reflects on the history and literature to tell the storied evolution of prosthetic design . He takes the reader on a journey to consider his theories, which have substantive foundations to contemplate. By the end of chapter one, we have the basic h- tory and an appreciation for the rationale behind the “rolling joint ankle” with evidence to support his theoretical views.