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 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 Design of an Ankle Prosthesis for Two degree of freedom Motion in the Sagittal and Coronal Planes written by Colin Elley and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The ability to get up and walk from one place to another under one's own power epitomizes a level of independence and the perception of a good quality of life. Loss of this ability can directly affect one's level of physical fitness and thus critically affect health and well-being. This ability to independently walk can be lost due to many causes including lower leg amputation. This leads to the need for an ankle prosthesis to aid the user in performing gait. Most current commercial ankle prostheses available for below-knee amputees allow for (limited) dorsiflexion and plantarflexion at the ankle. Therefore, the primary objective of this project was to develop an ankle prosthesis which can passively accommodate two degrees of freedom: motion in the sagittal plane (dorsiflexion and plantarflexion) and motion in the coronal plane (inversion and eversion). Two design iterations were done to accomplish this goal. The second design or Design 2 utilizes three torsion springs to passively allow for bi-planar motion in the sagittal and coronal planes. The range of motion for the ankle prosthesis was based on the range of motion of the ankle during normal gait and also accounts for the maximum grade and cross-slope of rural local streets. The Design 2 ankle prosthesis offers slight variability for motion in the sagittal plane by varying the stiffness of the ankle prosthesis for dorsiflexion and plantarflexion. With the exception of the latter part of the pre-swing phase, the theoretical behavior of the ankle prosthesis qualitatively replicates that of natural ankle motion in the sagittal plane found in literature. It also provides sufficient lateral stability during normal gait. The ankle prosthesis which was designed for this project can passively accommodate motion in both the sagittal and coronal planes as well as provide some degree of "push-off" during normal gait.

Download or read book Virtual Constraint Control of Powered Prosthetic Legs written by David Quintero and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The lower limb amputee population is gradually increasing, primarily due to complications from vascular diseases. The vast majority of lower limb amputees use mechanically passive prosthetic legs, which are unable to provide energy input at the joints and can only dissipate energy during locomotion. To improve amputee gait, powered prosthetic legs are in development. Several control methods have been proposed for these devices, but almost all of them divide the gait cycle into multiple, sequential periods with different controllers. This results in many patient-specific control parameters and switching rules that must be tuned for a specific ambulation mode, such as a desired walking speed or slope. The different periods of gait could potentially be unified over the entire gait cycle by virtual kinematic constraints that are enforced using a torque control scheme. The prosthetic control method proposed as part of this dissertation work unifies the different periods of gait through virtual constraints that are driven by a human-inspired phase variable. A phase variable is a kinematic quantity corresponding to an unactuated degree of freedom that evolves monotonically during steady walking, thus representing the progression through the gait cycle. The unified controller was designed systematically by method of virtual constraints, which was implemented within an amputee biped walker model for different walking speeds. To validate this control strategy even further, a powered knee-ankle prosthesis was designed and built during the course of this dissertation work for experimental validation. The mechanical design and real-time control of the powered prosthesis is presented. Experiments were conducted with multiple above-knee amputee subjects walking across various speeds and inclines, while no control parameters were tuned. This verified that our unified control scheme can work seamlessly and efficiently for multiple amputee users, and also, for different ambulation modes without retuning the controller. Furthermore, this work has taken a step forward to providing a solution of the technical challenges for powered knee-ankle prostheses to be used in a clinical setting. An intuitive clinical user interface was developed for clinicians to change the prosthesis control based on their clinical insight and expertise. We performed a case study with a clinician adjusting the virtual constraint design on the prosthesis, which resulted in improvement of the amputee’s gait symmetry using our control strategy.

Download or read book Two Degree of Freedom written by Bryan C. Ross and published by . This book was released on 2010 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Preliminary Design Approach for Prosthetic Ankle Joints Using Compliant Mechanisms written by Jason Wiersdorf and published by . This book was released on 2005 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this thesis is to develop design approaches and models for prosthetic ankle joints using kinematic models of the human ankle and compliant mechanisms technology. Compliant mechanisms offer several potential design advantages over traditional rigid-body designs including high reliability and low cost. These design advantages are ideal for use in prosthetics. Some prosthetic ankle/foot systems currently on the market have multiple degrees of freedom yet are expensive. Additionally, even though these systems have multiple degrees of freedom, none of them are designed after the actual movements of the biological ankle. In this thesis a two, single degree-of-freedom hinge joint model, which is a kinematic model based on the biological ankle during walking, is used to develop compliant prosthetic ankle joints. The use of the model together with compliant mechanisms may provide the ability to develop highly functional prosthetic ankle joints at a lower cost than current high-performance prosthetic systems. Finally, a design approach for ankles may facilitate future development for knees, hips or other biological joints.

Download or read book Anthropometric Survey ANSUR II Pilot Study written by Steve Paquette and published by . This book was released on 2009 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Virtually every Army materiel system in use was designed and/or sized using a database of anthropometric information that is 20 years old. It was based on the Army Anthropometric Survey (ANSUR), which was conducted in 1988 on only Active Duty Soldiers. However, more than one-half of today's fighting forces are National Guard and Reserve component troops. A pilot study (ANSUR II) was recently undertaken to (1) assess anthropometric change since 1988 within the Active Army; (2) to assess anthropometric differences among Army Active, Reserve, and National Guard components; and (3) to provide guidance on whether a further, more comprehensive survey and an update of the current ANSUR database are needed. This report provides measurement methods and summary statistics for 25 body measurements made on 2811 male and 651 female soldiers in the pilot study. The anthropometric change since 1988 and tests of component differences are presented in a separate technical report. The subjects were weighted by component, sex, age, and racial/ethnic group to match Total Army demographics as of March 2007 in order to provide interim design guidance on Total Army body size distributions as of March 2007." --- (report documentation page).

Download or read book Journal of Rehabilitation Research and Development written by and published by . This book was released on 1987 with total page 1032 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Mechanical Design and Control System Development of Novel 2 Degree of freedom Ankle and Balance Rehabilitation Robotic System written by Amir Bahador Farjadian Bejestan and published by . This book was released on 2015 with total page 202 pages. Available in PDF, EPUB and Kindle. Book excerpt: Stroke is a leading cause of serious long-term disability in the United States. Ankle and balance disabilities are caused by neurological impairments such as traumatic brain injury, cerebral palsy and stroke. Due to increased survival rates after stroke, significant growth in stroke population is projected by 2030, which will make rehabilitation procedures even more important. Common rehabilitation techniques require intensive cooperation and effort of therapists and patients over prolonged sessions. Conventional ankle and balance rehabilitation systems are built from a simple set of mechanical elements which lack sensory systems or networks. Current more advanced technologies do not combine ankle strength, mobility, motor control and coordinated balance training in one device that can retrain the patients in multiple positions from sitting to standing. In this work, we present the Virtually-Interfaced Robotic Ankle and Balance Trainer (vi-RABT), a low-cost platform-based robotic system that is designed to improve overall ankle/balance strength, mobility and control. The system is equipped with two degrees-of-freedom (DOF) controlled actuation along with complete means of accurate force and angular measurements. Effective control techniques and virtual reality games were developed and interfaced into the system hardware. Under IRB approved protocol, the system was used to assess ankle force, mobility and motor control in a pool of healthy human subjects, while playing interactive virtual reality games on a large screen. In the next phase, an anisotropic assistive/resistive control paradigm has been implemented into practice, with realistic functionality consistent with the expectations of a Physical Therapy expert. A pilot experiment was conducted to investigate the feasibility of assistive control using vi-RABT. The inspiring results on the pool of human subjects suggest that, in contrast to the upper extremity, subjects have better control over ankle's position than the force they can regulate. The early results on the assistive control showed that, in the presence of objective force feedback, subjects finished the game in a shorter time and with fewer errors. The ankle rehabilitation aspect of the system is ready to be utilized in physical therapy. Further research is required to develop the balance rehabilitation paradigm. Vi-RABT has the potential to be used for variety of ankle and lower extremity neuromuscular impairments.

Download or read book Design and Control of a Powered Transfemoral Prosthesis written by Frank Charles Sup and published by . This book was released on 2006 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Biomechanics and Motor Control of Human Gait written by David A. Winter and published by . This book was released on 1991 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Design of a Multiple Degree of Freedom Prosthesis written by Robert Bristol Jerard and published by . This book was released on 1970 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Optimal Design and Control of a Lower limb Prosthesis with Energy Regeneration written by Holly E. Warner and published by . This book was released on 2015 with total page 137 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: The majority of amputations are of the lower limbs. This correlates to a particular need for lower-limb prostheses. Many common prosthesis designs are passive in nature, making them inefficient compared to the natural body. Recently as technology has progressed, interest in powered prostheses has expanded, seeking improved kinematics and kinetics for amputees. The current state of this art is described in this thesis, noting that most powered prosthesis designs do not consider integrating the knee and the ankle or energy exchange between these two joints. An energy regenerative, motorized prosthesis is proposed here to address this gap. After preliminary data processing is discussed, three steps toward the realization of such a system are completed. First, the design, optimization, and evaluation of a knee joint actuator are presented. The final result is found to be consistently capable of energy regeneration across a single stride simulation. Secondly, because of the need for a prosthesis simulation structure mimicking the human system, a novel ground contact model in two dimensions is proposed. The contact model is validated against human reference data. Lastly, within simulation a control method combining two previously published prosthesis controllers is designed, optimized, and evaluated. Accurate tracking across all joints and ground reaction forces are generated, and the knee joint is shown to have human-like energy absorption characteristics. The successful completion of these three steps contributes toward the realization of an optimal combined knee-ankle prosthesis with energy regeneration.

Download or read book Journal of Rehabilitation Research Development written by and published by . This book was released on 1988 with total page 726 pages. Available in PDF, EPUB and Kindle. Book excerpt: