Dissertations / Theses on the topic 'Knee prosthesis design'

Thesis (Ph. D.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2012.
Cataloged from PDF version of thesis.
Includes bibliographical references (p. 92-96).
The loss of a limb is extremely debilitating. Unfortunately, today's assistive technologies are still far from providing fully functional artificial limb replacements. Although lower extremity prostheses are currently better able to give assistance than their upper-extremity counterparts, important locomotion problems still remain for leg amputees. Instability, gait asymmetry, decreased walking speeds and high metabolic energy costs are some of the main challenges requiring the development of a new kind of prosthetic device. These challenges point to the need for highly versatile, fully integrated lower-extremity powered prostheses that can replicate the biological behavior of the intact human leg. This thesis presents the design and evaluation of a novel biomimetic active knee prosthesis capable of emulating intact knee biomechanics during level-ground walking. The knee design is motivated by a mono-articular prosthetic knee model comprised of a variable damper and two series elastic clutch units spanning the knee joint. The powered knee system is comprised of two series-elastic actuators positioned in parallel in an agonist-antagonist configuration. This investigation hypothesizes that the biomimetic active-knee prosthesis, with a variable impedance control, can improve unilateral transfemoral amputee locomotion in level-ground walking, reducing the metabolic cost of walking at selfselected speeds. To evaluate this hypothesis, a preliminary study investigated the clinical impact of the active knee prosthesis on the metabolic cost of walking of four unilateral above-knee amputees. This preliminary study compared the antagonistic active knee prosthesis with subjects' prescribed knee prostheses. The subjects' prescribed prostheses encompass four of the leading prosthetic knee technologies commercially available, including passive and electronically controlled variable-damping prosthetic systems. Use of the novel biomimetic active knee prosthesis resulted in a metabolic cost reduction for all four subjects by an average of 5.8%. Kinematic and kinetic analyses indicate that the active knee can increase self-selected walking speed in addition to reducing upper body vertical displacement during walking by an average of 16%. The results of this investigation report for the first time a metabolic cost reduction when walking with a prosthetic system comprised of an electrically powered active knee and passive foot-ankle prostheses, as compared to walking with a conventional transfemoral prosthesis. With this work I aim to advance the field of biomechatronics, contributing to the development of integral assistive technologies that adapt to the needs of the physically challenged.
by Ernesto Carlos Martinez-Villalpando.
Ph.D.

Total knee arthroplasty (TKA) has revolutionized the life of millions of patients and it is the most efficient treatment in cases of osteoarthritis. The increase in life expectancy has lowered the average age of the patient, which requires a more enduring and performing prosthesis. To improve the design of implants and satisfying the patient's needs, a deep understanding of the knee Biomechanics is needed. To overcome the uncertainties of numerical models, recently instrumented knee prostheses are spreading. The aim of the thesis was to design and manifacture a new prototype of instrumented implant, able to measure kinetics and kinematics (in terms of medial and lateral forces and patellofemoral forces) of different interchangeable designs of prosthesis during experiments tests within a research laboratory, on robotic knee simulator. Unlike previous prototypes it was not aimed for industrial applications, but purely focusing on research. After a careful study of the literature, and a preliminary analytic study, the device was created modifying the structure of a commercial prosthesis and transforming it in a load cell. For monitoring the kinematics of the femoral component a three-layers, piezoelettric position sensor was manifactured using a Velostat foil. This sensor has responded well to pilot test. Once completed, such device can be used to validate existing numerical models of the knee and of TKA and create new ones, more accurate.It can lead to refinement of surgical techniques, to enhancement of prosthetic designs and, once validated, and if properly modified, it can be used also intraoperatively.

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2011.
Cataloged from PDF version of thesis.
Includes bibliographical references (p. 32).
This thesis presents the design and structural analyses of an experimental test bench for the characterization of an active biomimetic knee prosthesis currently being developed by the Biomechatronics research group at MIT Media Laboratory. Finite element analysis (FEA) is conducted to determine the maximum stress and material deflections of three principle components of the test bench and to verify their structural integrity. In addition, FEA is performed on the chassis of the active knee prosthesis when subjected to the expected loads associated with walking. The simulation results verify that the active prosthetic do not expect structural failure during level ground walking trials with above knee amputee participants. Finally, an empirical weight reduction strategy for the active knee is proposed and analyzed. This strategy aims to reduce distal leg mass which contributes to the overall energetic demands of amputee walking. FEA on the modified active knee prosthesis chassis validate the strategy modifications while maintaining the original design feature constraints.
by Jacky H. Lau.
S.B.

Thesis: S.M., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2014.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 69-73).
Compared to non-amputees, above knee amputees expend significantly more metabolic energy. This is a result of the passive nature of most knee prostheses, as the development of clinically successful powered knee prostheses has remained a challenge. The addition of powered elements, such as electric motors, allow prosthetic knees to more closely emulate natural knee biomechanics. However, the addition of powered elements presents a new challenge of creating energy efficient devices that do not require frequent charging or excessively large batteries. In this thesis, a general optimization routine was developed to simulate and evaluate the electrical economy of various actuator architectures. Advanced actuators utilizing variable transmissions with elastic elements were compared to direct drive actuators, series elastic actuators, and two novel mechanisms known as the continuously-variable series-elastic actuator (CV-SEA) and the clutchable series-elastic actuator (CSEA). The CV-SEA is similar to a traditional series-elastic actuator (SEA), but uses a controllable continuously-variable transmission (CVT) in between the series-elastic element and the motor. The CSEA included a low-power clutch in parallel with an electric motor within a traditional series-elastic actuator. The stiffness of the series elasticity was tuned to match the elastically conservative region of the knees torque-angle relationship during early stance phase knee flexion and extension. During this region of the gait cycle, the clutch was engaged and elastic energy was stored in the spring, thereby providing the reactionary torque at a substantially reduced electrical cost. The optimization routine showed that the electrical economy of knee prostheses can be greatly improved by implementing variable transmissions in series with elastic elements. The optimization routine also estimated that a CSEA knee prosthesis could provide an 83% reduction in electrical cost, when compared to an SEA knee prosthesis. Although the variable transmission actuators were predicted to be more electrically economical than the CSEA knee, their design complexity limits their current feasibility in a knee prosthesis. Thus, a fully autonomous knee prosthesis utilizing the CSEA was designed, developed and tested. The CSEA Knee was actuated with a brushless electric motor; ballscrew transmission and cable drive as well as commercial electrical components. The knee was lighter than the 8th percentile and shorter than the 1st percentile male shank segment. The CSEA Knee was tested in a unilateral above knee amputee walking at 1.3 m/s. During walking, the CSEA Knee provided biomechanically-accurate torque-angle behavior, agreeing within 17% of the net work and 73% of the stance flexion angle produced by the biological knee during locomotion. Additionally, the process of locomotion reduced the net electrical energy consumed of the CSEA Knee. The knees motor generated 1.8 J/stride, while the electronics consumed 5.4 J/Stride. Thus the net energy consumption was 3.6 J/stride, an order of magnitude less electrical energy consumption than previously published powered knee prostheses. Future work will focus on a custom, power-optimized embedded system and the expansion of the CSEA architecture to other biomechanically relevant joints for bionic prosthesis development.
by Luke Matthewson Mooney.
S.M.

Thesis (PhD)--Stellenbosch University, 2011.
ENGLISH ABSTRACT: The knee is the largest, most complicated and incongruent joint in the human body. It sustains very high forces and is susceptible to injury and disease. Osteoarthritis is a common disease prevalent among the elderly and causes softening or degradation of the cartilage and subcondral bone in the joint, which leads to a loss of function and pain. This problem can be alleviated through a surgical intervention commonly termed a “knee replacement”. The aim of a knee replacement procedure is to relieve pain and restore normal function. Ideally, the knee replacement prosthesis should have an articulating geometry similar to that of the patient’s healthy knee, and must allow for normal motion. Unfortunately, this is often problematic since knee prostheses are supplied in standard sizes from a variety of manufacturers and each one has a slightly different design. Furthermore, commercial prostheses are not always able to restore the complex geometry of an individual patient’s original articulating surfaces. This dissertation shows that there is a significant variation between knee geometries, regardless of gender and race. This research aims to resolve the problem in two parts: Firstly by presenting a method for preoperatively selecting the optimal knee prosthesis type and size for a specific patient, and secondly by presenting a design procedure for designing and manufacturing patient-specific unicompartmental knee replacements. The design procedure uses mathematical modelling and an artificial neural network to estimate the original and healthy articulating surfaces of a patient’s knee. The models are combined with medical images from the patient to create a knee prosthesis that is patient-specific. These patient-specific implants are then compared to conventional implants with respect to contact stresses and kinematics. The dissertation concludes that patient-specific implants can have characteristics that are comparable to or better than conventional prostheses. The unique design methodology presented in this dissertation introduces a significant advancement in knee replacement technology, with the potential to dramatically improve clinical outcomes of knee replacement surgery.
AFRIKAANSE OPSOMMING: Die knie is die grootste, mees komplekse en mees ongelyksoortige gewrig in die liggaam. Osteoarthritis is ’n siekte wat algemeen by bejaardes voorkom en die versagting of agteruitgang van die kraakbeen en subchondrale bene in die gewrig tot gevolg het, wat tot ’n verlies van funksionering en pyn lei. Hierdie probleem kan verlig word deur ’n chirurgiese ingryping wat algemeen as ’n “knievervanging” bekend staan. Die doel van ’n knievervangingsprosedure is om pyn te verlig en normale funksionering te herstel. Ideaal gesproke behoort die knievervangingsprostese ’n gewrigsgeometrie te hê wat soortgelyk aan die pasiënt se gesonde knie is, en normale beweging moontlik maak. Ongelukkig is dit dikwels problematies aangesien knieprosteses in standaardgroottes en deur ’n verskeidenheid vervaardigers verskaf word, wat elkeen se ontwerp effens anders maak. Verder kan kommersiële prosteses nie altyd die komplekse geometrie van ’n individuele pasiënt se oorspronklike gewrigsoppervlakke vervang nie. Hierdie proefskrif wys dat daar ’n betekenisvolle variasie tussen knieafmetings is, afgesien van geslag en ras. Hierdie navorsing is daarop gemik om die problem op tweërlei wyse te benader: Eerstens deur ’n metode aan te bied om die optimal knieprostesetipe en -grootte vir ’n spesifieke pasiënt voor die operasie uit te soek, en tweedens om ’n ontwerpprosedure aan te bied vir die ontwerp en vervaardiging van pasiëntspesifieke unikompartementele knievervangings. Die ontwerpprosedure gebruik wiskundige modellering en ’n kunsmatige neurale netwerk om die oorspronklike en gesonde gewrigsoppervlakke van ’n pasiënt se knie te bepaal. Die modelle word met mediese beelde van die pasiënt gekombineer om ’n knieprostese te skep wat pasiëntspesifiek is. Hierdie pasiëntspesifieke inplantings word dan met konvensionele inplantings vergelyk wat kontakstres en kinematika betref. Daar word tot die slotsom gekom dat die pasiëntspesifieke inplantings oor eienskappe kan beskik wat vergelykbaar is met of selfs beter is as dié van konvensionele prosteses. Die unieke ontwerpmetodologie wat in hierdie proefskrif aangebied word, stel beduidende vordering in knievervangingstegnologie bekend, met die potensiaal om die kliniese uitkomste van knievervangingsoperasies dramaties te verbeter.

Thesis: S.B., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2015.
Cataloged from PDF version of thesis.
Includes bibliographical references (page 55).
In this thesis, a novel torsion spring design for use in knee prostheses and exoskeletons is presented and analyzed. The planar spring design features an outer hub and an inner hub, which are connected by slender beams and store torsion energy in beam bending. The beams are fixed to the outer hub on one end and attached to the inner hub by a pin and slot on the other. The modeled spring design is capable of deflecting ± [pi]/6 radians, higher than any existing planar torsion spring designs, and is capable of providing 100 N-m of torque. The maraging steel spring is predicted to have a total diameter of 0.112 meters, width of 0.005 meters, and mass of 98 grams. With this form factor, the planar spring design provides a more compact alternative to elastic elements currently used in series elastic actuators. From the presented models, the design dimensions, material, and slot geometry can be parametrized to design springs that meet specific requirements for different applications. In addition to quantifying performance, the models presented provide the foundation for further weight, efficiency, and performance optimization.
by Thuan D. Doan.
S.B.

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2009.
Cataloged from PDF version of thesis.
Includes bibliographical references (p. 24-25).
Introduction: The design of prosthetic limbs is a complicated problem that continues to receive significant attention in research labs and in industry throughout the world. The idea of getting a machine to match human performance is an enticing one, and thus research continues to pursue the challenge of designing devices that can replace the functionality lost via limb amputation. Designers of prosthetics for developing countries face similar challenges. However, that challenge is also supplemented with a number of other contextual factors and considerations that must be made as a designer. As described by Cummings', these factors are social, economic, cultural, and geographic, and also include locally available forms of technology and time and distance constraints. These considerations further complicate the design process, especially for an engineer inexperienced with designing for the developing world and unfamiliar with the specific developing world environment being designed for. These topics have been covered in bits and pieces throughout the literature; this document attempts to cover them all thoroughly and in a logical way. This thesis also aims to provide some mechanism by which the challenge of designing a prosthetic knee for the developing world can be broken down and tackled effectively to yield an appropriate knee design. As amputees in the developing world are often subject to an inescapable life of poverty because they are unable to work and support their families, there is a strong impetus to design effective limbs for this population. This document intends to help facilitate that process. This thesis is inspired by a prosthetic knee design project that began in the class Developing World Prosthetics at the Massachusetts Institute of Technology in its inaugural term, spring 2008. Though the project was successful in many ways, the design process maybe could have been more effective with a stronger foundation in all the areas that will be covered below. This thesis primarily uses literature review to provide insight into human gait and amputee characteristics, as well as developing world considerations for designers of prosthetic limbs. The aim is to provide a foundation by which one can design effective and appropriate prosthetic devices. A metric is also developed by which those developing world considerations can be managed, weighed and incorporated into the design. In this case, experience and observations from the author's work on prosthetics in India are used to assess the contexts and contributions of various developing world factors to the successful incorporation of a prosthetic knee design into that environment. The document uses India as a case study; however, the thesis should serve as a generalized manual for developing world prosthetic knee design. This document begins with a presentation of human gait characteristics presented in a variety of contexts that can be useful to the designer of a prosthetic knee for the developing world. Then, basic mechanical components that are often used in prosthetic knee design are described, using examples. Finally, a thorough description of the many developing world factors that must be understood to design a sustainable prosthetic knee are discussed, and a table is presented by which those factors can be simply reviewed.
by Karina N. Pikhart.
S.B.

Thesis: S.B., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2017.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 38-39).
The need for effective prostheses is prevalent worldwide, and is especially dire in developing countries and low-resource settings. The MIT GEAR Lab is addressing this gap through the ATKnee, a low-cost, passive prosthetic knee that employs the use of spring and damper components to replicate the knee torque of the able-bodied human knee. In this study, we build upon prior work to optimize the components used in the ATKnee by accounting for results from field-testing. We first develop an inverse dynamics model to confirm understanding of previous work. We then use a genetic optimization algorithm to optimize parameters across different walking speeds and various spring-damper configurations. The best fit, as measured by the highest R2 value, is obtained when a viscous damper is active during the first dissipative phase (b*11 ), a friction damper is active during the second dissipative phase (b*/20 ), and an additional friction damper is active throughout both phases (b*/0). We make the suggestion that b*/0 = 0.084, b*/11 = 0.008, b*/0 = 0.183, gives the most optimal passive system knee torque with the engagement and disengagement timings teng = 51.3%, tdis1 = 64.2% for the first damper, and teng2 = 86.1%, tdis2 = 95.2% for the second damper. We find that the parameters are robust to subject body mass, but show a positive correlation with walking speed. We conclude that while we are able to suggest an optimized parameter set that includes higher order dampers, it will be important to investigate the effects of cadence, as well as to study the joint torques at the hip, which is further from the foot.
by Krithika Swaminathan.
S.B.

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2013.
Cataloged from PDF version of thesis.
Includes bibliographical references (page 29).
Amputees in developing countries face a challenging prospect. Without an adequate prosthesis, they face a lifetime of limited mobility and dependence. Unfortunately, as millions fall below the poverty line and as such do not have access to proper medical and prosthesis care, many must resign themselves to such a lifestyle. Bhagwan Mahaveer Viklang Sahayata Samiti (BMVSS) is attempting to change this. BMVSS is the world's leading prosthetics and mobility provider, serving over 20,000 new individuals per year - all free of charge - in 27 countries. Through a partnership with a Stanford design course, the Jaipur-Stanford Knee, a novel prosthetic knee incorporating a four-bar design, was born. This knee design has become widely popular amongst amputees and was named one of the top 50 best inventions in 2009 by Time Magazine. However, despite the popularity and widespread media coverage of the knee's development, there currently exists no available technical literature on the design. This research provides a kinematic model of this knee to compare to the dynamics of a natural gait along with a materials analysis to offer insight into design and manufacture improvements in future design iterations and concepts.
by Casandra N. Ceri.
S.B.

Thesis: S.M., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2015.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 51-54).
An estimated 230,000 above-knee amputees are in need of prosthetic devices in India with a majority of them facing severe socio-economic constraints in their daily lives. However, only a few passive prosthetic knee devices in the market have been designed to enable normative gait and to meet the unique daily life needs of above-knee amputees in the developing world. This thesis builds upon a past study at MIT, which established optimal mechanical component coefficients in prosthetic knee function required for achieving able-bodied kinematics. A mechanism for the design of a fully passive, low-cost prosthetic knee device, which aims to facilitate able-bodied kinematics at a low metabolic cost is presented. The mechanism is implemented using an automatic early stance lock for stability, a linear spring for early stance flexionextension and a differential friction damping system for late stance and swing control. For preliminary validation of the knee mechanism two field trials were carried out on five above-knee amputees in India, which showed satisfactory performance of the early stance lock and enabled smooth stance to swing transition by timely initiation of late stance flexion.
by Venkata Narayana Murthy, Arelekatti.
S.M.

High contact stresses are largely responsible for wear in polyethylene components of knee prostheses. As a result, an increase in the contact area of the femorotibial joint at high flexion angles is needed to decrease high contact stresses. At first, a morphometrical study was performed on 12 cadaveric distal femurs. A laser range finder device digitized their articular surfaces. A non-iterative algebraic algorithm was developed to reconstruct the medial and the lateral condyles in the sagittal plane by means of two circular arcs. The average geometry of all of the femoral condyles tested was then used to perform a parametric analysis which consists of studying the effect of the alterations of this geometry on the contact area extent of the joint. The results of this research indicate that a reduction of wear of the prosthesis cannot be achieved at high flexion angles without alterations of the current concepts of the design of knee prostheses.

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2009.
Cataloged from PDF version of thesis.
Includes bibliographical references (p. 32).
Prosthetic devices are designed for amputees in developed countries, made with materials, mechanisms, and research budgets prohibitive to individuals and communities in developing countries. A prosthetic knee for trans-femoral amputees is developed at MIT and tested on patients at the Jaipur Foot Organization in Delhi, India. By using kinematic models of the knee, information was gathered on the feasibility of incorporating a stance-flex knee flexion mechanism in the design. Results show an increase in the flexion torque required to buckle the device in stance phase, resulting in a more reliable gait for the amputee. It is concluded that the prototype designed is a feasible alternative to current knee technology present in developing countries, although incorporation of a stance-flex mechanism is not possible within the confines of the current design.
by Jared Asher Sartee.
S.B.

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2013.
Cataloged from PDF version of thesis.
Includes bibliographical references.
In January 2012, a partnership was initiated between the Massachusetts Institute of Technology and Bhagwan Mahaveer Viklang Sahayata Samiti (BMVSS, a.k.a., Jaipur Foot) to design a high-performance, low-cost, passive prosthetic knee for transfemoral amputees in India. The knee was primarily intended to improve the walking gait of amputees relative to existing low-cost devices. This thesis aimed to identify detailed design requirements for the prosthetic knee through user analysis and dynamic simulation. User analysis identified the needs and constraints of numerous stakeholders in the prosthesis development process. Members of the Indian biomechanics, prosthetics, and rehabilitation communities were interviewed to identify general requirements for the design, manufacturing, evaluation, and fitting of a prosthetic knee, and a structured survey of Indian amputees was conducted to quantify the demographics, functional capabilities, and functional needs of future end users. Dynamic simulation identified methods to enable transfemoral amputees to walk with reduced energy expenditure and normative gait kinematics. 2-dimensional inverse dynamics simulations were used to calculate the effects of inertial alterations of a prosthetic leg on the energy expenditure required to walk with normative kinematics. In addition, simulations were performed to compute the effects of inertial alterations on the knee moment required to walk with normative kinematics. Mechanical power analysis, sensitivity analysis, and optimization were used to formulate a passive mechanical model that could accurately reproduce the specified knee moment. The effects of walking cadence on critical results were also examined. Through the identification of user-centered and biomechanical requirements, the thesis provides a blueprint for the mechanism design comprising the next phase of the project.
by Yashraj S. Narang.
S.M.

Durch ansteigende Alterserwartung werden Behandlungen für Erkrankungen des Bewegungsapparats immer relevanter. Gerade das Knie wird über die Zeit hinweg stark belastet und ist auch durchgehend in Benutzung. Durch Fehlstellungen, Brüche oder auch Arthrose kann es zum kompletten Ver-schleiß dieses Gelenks kommen. Da in einigen Fällen die konservativen Behandlungsmethoden versagen, wird ein Ersatz des Kniegelenks in Erwägung gezogen. Dieser Ersatz wird heutzutage durch Standardprothesen schon gut abgedeckt. Die Bewegungsfähigkeit kann wiederhergestellt und Schmerzen können reduziert werden. Durch das weiterhin ansteigende Alter kommen immer mehr Revisionsendoprothesen zum Einsatz, da die Lebensdauer einer Knieendoprothese nur begrenzt ist. Um diese zu verlängern, kann man eine an den Bewegungsapparat individuell angepasste Prothese implantieren, die der Belastung besser gewachsen ist. Die Erstellung solcher individueller Prothesen ist Aufgabe des Forschungs- und Entwicklungsprojektes EXPERTEB (EXPERTEB 2018). Um solch eine angepasste Prothese herzustellen, benötigt dies jedoch konkrete Maße des Knies. Diese Arbeit soll ein Verfahren präsentieren, mit dem es möglich ist, anhand von CT-Aufnahmen des Kniegelenks alle nötigen geometrischen Maße zu bestimmen. Kern des Verfahrens ist ein angelerntes Statistical Shape Model (SSM), dass nur die nötigen und zu erwartenden Verformungen des Modells zulässt, sodass es sich an das im Datensatz dargestellte Knie anpassen kann. [... aus der Einleitung]

碩士
元智大學
機械工程研究所
89
This is an interdisciplinary research project in which surgeons and engineers investigate together the design of a total knee prostheses from various view points, including anatomy, biomechanics, kinematics, mechanical design, material. The purpose of this project is to design a reliable and robust total knee prostheses whose motion pattern is close to real knee. The characteristic of the new total knee prosthesis is the shape of meniscus was be designed to protrude, it can eliminate particle that was been ground. The contact face of femur and meniscus was designed to dual inclusive line, it can make maximum contact face, reduce contact stress, when human standing or in the flexion and extension period. The new total knee prosthesis can flexion and extension to 150 degrees, when it flexion to 150 degrees, the anterior direction displacement of femur center is 8.98mm, the amount of axis rotation is 15.16 degrees, the A-P displacement is 4.05mm, and the sidelong slides is 4mm. Due to the guide surface, the new total knee prosthesis have good stability when it produce relative motion.

碩士
國立臺北科技大學
製造科技研究所
93
This research presents a new mechanism design for safe prosthesis knee joint and knee brace. It primarily includes the following two phases: The first phase is to design a safe prosthesis knee joint. We would understand the motions of the knee joints through analyzing normal human gaits. Through studying the related patents, we obtain the design requirements and the advantages and disadvantages of current designs. In follows that we point out the insufficiencies of the existing prosthesis knee joints. Taking the findings from the literature study as the design goal, we develop an innovative mechanism of prosthesis knee joint. This innovative mechanism can prevent the users from falling during walking and standing, and also allow the user’s legs to have some appropriate squatting exercises. Besides, through design optimization, the interacting resistance between the stump and the socket can be minimized, and it can also meet the requirements of comfort and safety. The feasibility of this innovated mechanism has been tested and verified by dynamic simulation and analysis from the ADAMS software. As for the other phase of this research, it focuses on how to apply this safe prosthesis knee joint mechanism on the design of assistive knee brace. This knee brace is designed for polio sufferers and the one having unstable lower limbs as well. In fact, the existing knee braces cannot completely meet the design requirements stated above. Therefore, it is necessary to use the same design concept of safe prosthesis knee joint onto that of the knee brace. However, due to the limitations of the weight and space of the knee brace and the requirement that the device has to be worn on normal lower limbs, therefore, the original design for the safe prosthesis knee joint has been modified to meet the needs in assistive devices appearance and practicability.

碩士
國立臺灣大學
機械工程學研究所
99
Through integrating a new developed flow control valve into the hydraulic cylinder, this thesis has realized an adjustable small hydraulic damper for the above-knee prostheses. The damper is mainly composed of a double-rod hydraulic cylinder and an external attached flow control valve. By regulating the flow channel length inside the flow control valve, the damping effect of the damper can be varied. The key elements of the adjustable flow control valve are the flow control ring and the circular wedged ring. The fixed flow control ring possesses a narrow flow channel. And the circular wedged ring is fixed on a shaft, which can be manually operated or driven by motor. By rotating the circular wedged ring, the flow channel length between the flow control ring and the circular wedged ring can be proportionally varied. Through the modular design concept, these two elements can be easily adaptable to different damping requirements and maintenance. The characteristic performance of our developed adjustable damper is theoretically analyzed to comprehend the influences of the design and operational parameters. Besides, its performance is also experimentally verified. The relation between the damping force F and the actuation speed v is nonlinear. For the actuation speed range of 180 mm/s , the damper can reach a maximum damping force of 878 N, which supplies a sufficient supporting capacity for most peoples. The damper performance can be significantly influenced by the assembly errors and the manufacture precision.

It has been noticed that the need for total knee replacement surgery is increasing for Asian region. A total knee replacement is a permanent surgical solution for a patient having debilitating pain in knee joint suffering from arthritis. In this surgery, knee joint is replaced with components made up of bio-compatible materials after which the patient can resume the normal day to day activities. Western population has bigger build compared to Asian population. Most of the total knee replacement prosthesis are designed for western population. When these total knee prosthesis are used for Asian population, they cause a mismatch leading to various clinical complications such as reduced range of motion and pain. The studies have been limited to clinical complications caused by the mismatch. To address this limitation, current study is aimed to find the mechanical implications such as stress distribution, maximum stresses, maximum displacements etc., caused by mismatch of total knee replacement components with knee. A surgeon selects total knee components for a patient based on some critical dimensions of femur and tibia bone of knee. In addition, a method to accurately calculate these dimensions of the femur and tibia bone of a real knee was developed in the current study. This method calculated the points of curvature greater than a threshold (decided based on the radius of the curvature) found out using the formula of curvature. Further, the highest point was calculated based on maximum height from a line drawn between initial and final point within the captured points, also the extreme points were calculated based on the sign change in slope of points within the captured points, giving multiple points on the boundary of bones extracted in an MRI image of a patient. The distance between two selected farthest points, out of these points, in specific direction was the basis for selection of the TKR components. Total knee replacement components were modeled in Geomatics Studio 12 software, bones were modeled in Rhinoceros 5 software, assembly of bones and total knee replacements components was done in Solid works 2013 software, the finite element model of the assembly was developed in Hyper mesh 11 software and, the stress analysis and post processing was done in ABAQUS 6.13 software. A static, implicit non linear analysis was performed. Simulations were performed for two conditions: at standing (0o of flexion) and at hyper-flexed (120o of flexion). In order to figure out if there were any mechanical implications of mismatch, the full model of assembly consisting of femur, tibia and fibula bones assembled with total knee replacement components, and the reduced model consisting of only total knee replacement components were simulated separately, results of which have been discussed in the current thesis. In this work, the effect of change of length of ligaments at 120o of flexion in detail was also studied. This study brought out various outcomes of contact mechanics and kinematics between the components of total knee replacement prosthesis.

碩士
國立交通大學
工學院碩士在職專班精密與自動化工程組
98
In design of a prosthesis knee, it is very important to analyze the patents to ensure the design will not infringe current intellectual property rights. In this study, the patent information engineering design approach is used for searching, collecting and analyzing of relevant patents. The results are used for constructing the first patent data. According to the first patent data, a patent analysis abstract approach is used not only to de-construct the technologies using in analyzed patents, but also to construct the second patent table built by the technical characteristics, components, manners, functions, and effects. Based on the first patent data and second patent table, a patent map analysis approach is further used to form a patent technical functional matrix underlying the characteristics of technical functions and components of analyzed patents. The goal of this step is to find out the empty technology and to be as the base of creating a new product without infringing existing patents. After getting the relevant technical characteristics of a prosthesis knee including a Tibia, a Femoral, a Knee Joint and a Meniscusm from analyzed patents, the thesis uses the Quality Functional Deployment, QFD, to make a link between customers’ need and the engineering design of a prosthesis knee to certainly fulfill the practical need of customers. The procedure is to treat the analyzing results gotten from analyzed patents as information and translate them to the customers’ needs. Those needs are set as the required qualities of a prosthesis knee and assigned weights. Then, the planned qualities can be obtained by means of comparison on all products among all companies. Finally, the thesis performs a design of a prosthesis knee using the conceptual design approach with the engineering technical specifications gotten from the required qualities and planned qualities by QFD. Consequently, the design of a desired prosthesis knee based on those technical specifications without infringing is archived

The few microcontroller based active/semi-active prosthetic knee joints available commercially are extremely expensive and do not consider the uncertainties of inputs sensory information. Progressing in the controller of the current prosthetic devices and creating artificial lower limbs compatible with different users may lead to more effective and low-cost prostheses. This can affect the life style of lots of amputees specially the land-mine victims in developing war-torn countries who are unable to partake in the advancement of the current intelligent prosthetic knees. The purpose of the proposed Active Prosthetic Knee (APK) design is to investigate a new schema that allows the device to provide the full necessary torque at the knee joint based on echoing the state of the intact leg. This study involves the design features of the mechanical aspects, sensing system, communication, and knowledge-based controller to implement a cost-effective APK. The proposed microcontroller based prosthesis utilizes a ball screw system accompanied by a high-speed brushed servomotor to provide one degree of freedom for the fabricated prototype. Moreover, a modular test-bed is manufactured to mimic the lower limb motion which contributes investigating different controllers for the prototype. Thus, the test bed allows assessing the primary performance of the APK before testing on a human subject. Different types of sensing systems (electromyography and lower limb inclination angles) are investigated to extract signals from the user’s healthy leg and send the captured data to the APK controller. The methodology to measure each type of signal is described, and comparison analyses are provided. Wireless communication between the sensory part and actuator is established. A knowledge-based control mechanism is developed that takes advantage of an Adaptive-Network-based Fuzzy Inference System (ANFIS) to determine knee torque as a function of the echoing angular state of the able leg considering the uncertainty of inputs. Therefore, the developed controller can make the APK serviceable for different users. The fuzzy membership function’s parameters and rules define the knowledge-base of the system. This knowledge is based on existing experience and known facts about the walking cycle.

碩士
國立陽明大學
醫學工程研究所
97
The knee arthroplasty has been developed for nearly half a century. The primary goal for knee arthroplasty was to relieve pain without fully considering about the mechanism of knee joint movement. The survival rate was limited due to the decreased range of motion and the loosening or rupture of knee joint prosthesis. Following the improvement of medical techniques, the survival rate of the knee arthroplasty has increased up to 90% nowadays. Previous studies indicated that there are the differences of knee joint kinematics between artificial and normal knee joint. These differences might be one of the reasons for the range of motion limitation after arthroplasty and contributed to further disability in daily activities. Few researches focused on how the asymmetric component of knee arthroplasty improves the kinematic performance. We changed the diameters and the heights of the curvature center at medial condyle to construct two sets of asymmetric femoral component. The purpose of this study is then (1) to investigate the effect of different parameters of asymmetric femoral component on knee flexion kinematics; (2) to compare the maximal flexion angle among different contour designs of knee arthroplasty components. The results revealed that the design of increased the curvature diameter and the height of center can increase the tibal internal rotation and the amount of posterior movement of lateral condyle. Comparing with traditional designs, the changed contour design of component influences the length of ligaments during knee flexion. The ligament length may affect the knee joint kinematics and the maximal flexion angle after surgery. Dynamic simulation method was successfully applied to explore the effect on the knee kinematics in different designs of knee prothesis.

In a world of war and turmoil in developing nations, land mines are becoming a concern, as millions of them are scattered in countries all over the world. Moreover, land mine prevention programs cannot clear land mine fields as fast as they are detonated each day. As a result, there are thousands that fall victim each year. There is immense demand for newer technologies to replace the aging prostheses used in these war torn nations. The active prosthetic knee (APK) design project is a novel design that utilizes simple, robust one degree of freedom (DOF) mechanics, while providing fully active knee torque control. The APK utilizes a high-speed brushed servomotor, providing the necessary torque and dynamics to provide the necessary gait characteristics of human locomotion. The main research contributions of this thesis are: 1) the mechanics and 2) the intelligence of the APK. This thesis investigates and highlights the prosthetic’s design process. The human biological system is studied and used as the design criteria when designing the device. Anthropometric data was used to determine the sizing and other physical properties. Moreover, Adaptive-Network-based Fuzzy-Interference Systems (ANFIS) and Fuzzy Interference Systems (FIS) are used to provide control to the APK. Finite element analysis (FEA) verifies the structural integrity of the APK. Four simulations are analyzed: equivalent stress, equivalent strain, shear stress and total deformation. These four simulations provide a mathematical interpretation of the physical system. We found that the first prototype, although a sound design, can be further improved to allow greater loading capabilities. Moreover, cyclical loading and total life cycles would also be significantly improved. A modular test stand is also designed and prototyped to allow APK testing. Since the APK prototype cannot be immediately placed on a human test subject, the test stand allows for experimentation in replicating human gait cycles.

A rear locking prosthetic knee joint with a durable, rear Automatic Stance-Phase Lock (ASPL), was developed to investigate the versatility of the (ASPL) mechanism in improving the functionality of prosthetic knees appropriate for a global market. An international survey and a Quality Function Deployment identified deficits with existing prosthetic knee mechanisms and established the most influential design parameters. Work on the knee design was completed following a comparative stability analysis of different knee mechanisms which justified the initial design. Solid models were generated with computer design software and a prototype was produced and structurally tested. Finally, clinical pilot testing was conducted on a unilateral transfemoral amputee, and various gait variables were assessed. As hypothesized, the knee performed close to the level of a conventional six-bar knee providing highly effective stance-phase control and the pilot test showed that improvements to the swing-phase response could further reduce the asymmetry of gait.

Unilateral below-knee amputees commonly experience asymmetrical gait patterns and develop comorbidities in their intact (non-amputated) and residual (amputated) legs, with the mechanisms leading to these asymmetries and comorbidities being poorly understood. Prosthetic feet have been designed in an attempt to minimize walking asymmetries by utilizing elastic energy storage and return (ESAR) to help provide body support, forward propulsion and leg swing initiation. However, identifying the influence of walking speed and prosthetic foot stiffness on amputee gait mechanics is needed to develop evidence-based rationale for prosthetic foot selection and treatment of comorbidities. In this research, experimental and modeling studies were performed to identify the influence of walking speed and prosthetic foot stiffness on amputee walking mechanics. The results showed that when asymptomatic and relatively new amputees walk using clinically prescribed prosthetic feet across a wide range of speeds, loading asymmetries exist between the intact and residual knees. However, knee intersegmental joint force and moment quantities in both legs were not higher compared to non-amputees, suggesting that increased knee loads leading to joint disorders may develop in response to prolonged prosthesis usage or the onset of joint pathology over time. In addition, the results showed that decreasing ESAR foot stiffness can increase prosthesis range of motion, mid-stance energy storage, and late-stance energy return. However, the prosthetic foot contributions to forward propulsion and swing initiation were limited due to muscle compensations needed to provide body support and forward propulsion in the absence of residual leg ankle muscles. A study was also performed that integrated design optimization with forward dynamics simulations of amputee walking to identify the optimal prosthetic foot stiffness that minimized metabolic cost and intact knee joint forces. The optimal stiffness profile stiffened the toe and mid-foot while making the ankle less stiff, which decreased the intact knee joint force during mid-stance while reducing the overall metabolic cost of walking. These studies have provided new insight into the relationships between prosthetic foot stiffness and amputee walking mechanics, which provides biomechanics-based rationale for prosthetic foot prescription that can lead to improved amputee mobility and overall quality of life.
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博士
國立陽明大學
醫學工程研究所
94
The long-term survival rates of most posterior-stabilized total knee arthroplasties have been satisfactory. The post-cam mechanism in posterior-stabilized knee is designed to provide anteroposterior stability. However, recent retrieval studies have indicated a high incidence of polyethylene wear on the tibial posts. The wear region was primarily indicated on the anterior post due to femoral component is impinged with anterior side of tibial post during knee hyperextensions. In addition, post wear was also found on posterior side of the tibial post when femoral cam is engaged to the post during deep knee flexions. Analyzing the stresses on various designs of tibial posts should predict the risk of damage. The contact surfaces of the femoral cam and tibial post can be generally categorized into either flat on flat or curve on curve design. The objective of the study was to investigate the influence of post-cam design features on stresses of tibial post when anterior tibial post impingement and posterior tibial post engagement were occurred. Three-dimensional finite element models of the posterior-stabilized total knee prostheses were respectively constructed with flat on flat and curve on curve contact surfaces in tibial post and femoral cam. Convergence test and validation of the finite element models were performed before analysis. In the simulation of anterior tibial post impingement, a vertical compressive load of 2,000 N and an extension moment of 45 Nm were applied to the femoral component. Three hyperextension angles (0°, 5° and 10°) and axial tibial rotations (0°, 2.5° and 5°) were assumed to simulate different knee alignments. In the simulation of posterior tibial post engagement, an anteroposterior shear force of 500 N was applied to the femoral component at 60°, 90°, 120°, and 150° of knee flexions. Neutral contact and 10° of axial tibial rotation contact were also simulated. The femoral component was assumed to be a rigid body. The material property of the polyethylene insert was set as an elastoplastic behavior with Poisson’s ratio of 0.45. The von Mises stress, peak contact stress and maximum principal stress on the tibial post were calculated to compare the difference between both design features. In the simulation of anterior tibial post impingement, the flat on flat model had high increase in stresses when hyperextension or tibial rotation was simulated; the maximum increase was 68 % in peak contact stress, 125% in von Mises stress and 58 % in tensile stress when 10° of hyperextension with 5° of axial rotation was simulated. There was lesser stress increase in the curve on curve design. In the simulation of posterior tibial post engagement, the greatest increment of maximum von Mises stress in the flat on flat model was 126.3% and contact stress was 151%, while in the curve on curve design they were 10.7 % and 7.2%, respectively. There were higher contact and tensile stresses in the flat on flat design than curve on curve one when anterior tibial post impingement and posterior tibial post engagement were simulated. Tibial post failure can occur during hyperextension or deep bending of knee joint. The post-cam mechanism does not afford entirely innocuous articulation on all contacting surfaces, and stress concentration at the post should be avoided. The results of this study can provide good concepts for modifying design features of post-cam mechanism. The posterior-stabilized knee with curve on curve design feature on the post-cam mechanism can offer the advantage of mitigating the edge loading and to accommodate axial tibiofemoral rotation.

博士
國立陽明大學
醫學工程研究所
99
Backgrounds. Posterior stabilized total knee arthroplasty (PS TKA) has shown satisfactory long-term survivorship. In recent years, more functional restoration of natural knee motion has been demanded by TKA recipients, given factors such as younger patients and differing lifestyles. However, knee kinematics after PS TKA was significantly inconsistent with that of the intact knee. Specifically, tibial rotation and femoral roll-back decreased significantly after PS TKA. Factors affecting tibiofemoral motion include component design and surrounding soft tissues. The post-cam mechanism of the PS knee has been demonstrated to guide tibiofemoral motion. The contact features of the mechanism can be divided into flat-on-flat or curve-on-curve design. Besides, altering the function of collateral ligaments through adjustment of the joint line level may affect the joint laxity, leading to different motion pattern. The objective of the current study was to analyze the knee kinematics of PS TKA with various post-cam designs and to evaluate the influence of joint line variation on the function of collateral ligaments. Methods. A dynamic knee model was utilized for all analyses in this study. Two PS knee models were constructed with flat-on-flat and curve-on-curve post-cam designs. Knee flexion was driven from the linking line of condyle centers. Axial tibial rotation and anteroposterior femoral translation were measured from full-extension to 135° of flexion. The knee model was also used to investigate the influence of joint line variation. The joint line was shifted 3 mm and 5 mm both proximally and distally from the anatomic level. Any change in distance between attachment sites of collateral ligaments was expressed as a percentage from full-extension to 135°, with the goal of comparing the difference between varying joint line positions. Results. Internal tibial rotation increased with knee flexion in both flat-on-flat and curve-on-curve designs. Before post-cam engagement, the magnitude of tibial rotation approximated 8° in the two designs. However, tibial rotation angle decreased beyond femoral cam engaged with tibial post. The rate of reduction of tibial rotation was relatively lower in the curve-on-curve design. At the extreme flexion, the curve-on-curve design had 4.9° of internal tibial rotation while it was only 0.9° for the flat-on-flat design. For joint line variation, the elevated joint line increased the distance between ligament attachments. The maximum increment in the lateral and medial collaterals was 18.1% and 7.4%, respectively. Oppositely, lowering the joint line led to a further decrease in distance of 20.5% and 6.0%. Conclusions. Through the analysis of different post-cam design features, the curve-on-curve post-cam design showed the ability of providing smoother axial tibiofemoral motion which helps for the achievement of functional activities. However, further modification of the post-cam design is necessary to accommodate greater tibial rotation during high knee flexion. For joint line variation, a lowered joint line could relieve joint stiffness, improving tibiofemoral movement. Elevation of the joint line further constrains knee motion. On the other hand, once excessive collateral ligament laxity resulting from considerable deformity is recognized, an orthopaedic surgeon can augment the joint line with the goal of achieving joint stability.

碩士
長庚大學
醫療機電工程研究所
97
The conventional above-knee prosthesis design have a well-known feature of passive knee flexion and extension construction, the trajectory of instant center of rotation (ICR) throughout the entire range of knee flexion and extension different from the normal semicircular ICR trajectory for the tibiofemoral joint during spontaneous walking, therefore, the conventional above-knee (AK) prosthesis can not restore the normal gait pattern. In addition, the passive knee mechanical constuction of the conventional AK prosthesis design, allow the hip flexor govern the hip flexion movement during walking. It make the amputee to swing his prosthetic leg out of the way which produce a compensatory mechanism cause abnormal gait and excessive energy consumption during walking. Besides, the hinge of conventional AK prosthesis with mechanical, hydraulic or pneumatic locking systems for controling knee joint damping will only ensure knee joint stability under a constant speed rotation. Otherwise, the abnormal kinesiology reponse and fall will occur. In addition, intraskeletal impact forces generated by body movement are directly transmitted from the pelvis through conventional above-knee prosthesis will cause a higher concentration force at the contact surface between the socket and the relatively soft living bone. The higher contact force and continuous impact phenomena may induce pain or tissue necrosis. In order to breakthrough the drawbacks of the traditional design of AK prosthesis, a biocybernetic power assisted AK bionic prosthesis was developed. In this study, carried out in three parts; the first part for the air cylinder for filling with the gait cycle were deflated just enough structural design, the study includes software tools to build Solid Words - x - cylindrical inflatable balloon design and use of TRIZ creative design software gait cycle gas filling the structural design of full justice. In this study, the use of stripping thinking (TRIZ) method of solution of the problem in a mean 39 contradiction matrix, 40 creative principles and the principle of functional analysis, as a condition of airbag design constraints for tube method, and then a systematic and logical as a prompt put forward for the three adjustable tube-type airbag structure, the alternate line of airbags for tube, spiral tube for the turn-style airbags and airbag non-alternating cylindrical tube, such as contractors, including alternate-line airbags, airbag spiral because of the turn-style rechargeable deflated, the balloon will be deflated due to not fully close together in the body, caused by pressure on the formation of China by air bags in the gaps, do not meet the design requirements of this study, this study, the use of non-turn-type cylinder airbag for airbag inflatable tube to make for the structure; the material in the choice of balloon was used TPU (thermoplastic polyurethane) flexible materials, balloon design geometry using the Labor Safety and Health Department of the Institute of the human body measurement data released Treasury as the basis, for each cylinder 2 airbags, body parts and for which the cylinder is located at the bottom of the ball for half airbags, its radius of 90mm, the other a group of air inside the Department of the cylindrical tube for air bags, the size of the circle within to 560mm, thickness, 40mm, height 140mm, As air pressure is based on the Taiwan Society of vascular surgery treatment of edema of the study, an inflatable pressure value set 50mm-Hg. Through the regulation of air pressure safety valve through the sufficient to cope with the gait cycle were deflated. Inflatable used in this study for the metal core component of industrial production by micro-cylinder (model MCMB-11-20-80): Cylinder bore 32mm, stroke - xi - 80mm). Gait cycle gas just sufficient enough for the structure including the connecting tube and just enough space in the eight-shaped tube and adequate justice. Hollow tube with a compression spring within the other as a necessary and sufficient to promote the use of gas piston rod of the function, just feet from the cable linked with the piston rod of the swing period of the reversion of the position. The second part of this study for the design and development, "electrical stimulation-induced muscle compensation module" and "the soles of the feet feeling the pressure sensing feedback compensation module", the major projects including the development of electrical stimulation-induced muscle pressure compensation modules and the soles of the feet sensory feedback sensor signal compensation module design, FES barbed electric actuator timing calibration of the programming department patients after electrical stimulation threshold, in accordance with the patients given gait cycle the hip extension and flexion muscle stimulation, the current just enough after the thin-film pressure group pressure sensing element, respectively, for receiving the pressure of a sense of value, MSP430 single chip by the interpretation will be given electrical stimulation of the output and to provide patients with electrical stimulation; in time of electrical stimulation of the pressure sensor under pressure time, with the patient's gait cycle. When followed in the rear foot for stretching the hip muscle electrical stimulation and follow the prompts patients to rear foot, if the heel with a heel after landing at the same time, then give the hip extension and flexion muscle electrical stimulation, and prompts after patients with a heel to the heel at the same time, the last off the current when the heel to give the hip flexion muscles electrical stimulation, and at the same time to inform patients at this stage for the upcoming off before the heel, the - xii - bottom line in just before and after adequate Measurement of the pressure group placed a thin-film pressure sensing element as the soles of the feet during the gait cycle, the pressure feedback stimulation FES hip extension and flexion muscles, controlling the core by the Texas Instruments MSP430 single chip (model: MSP430xG4618IPZ), in detail design based on IAR Embedded Workbench IDE for MSP430 single chip programming tools, programming the pressure of the stampede into 25kg, 35kg and 45kg in three phases, respectively, to give control to trigger electrical stimulation to stimulate the three-phase voltage output. The third part of this study for the design of major items of work to develop "bionic knee institutions" and "like a tube of gas-controlled electrical stimulation for knee prostheses-style integration." Design of bionic knee imitation of normal knee movement, the study formula derived Dragon calculated instantaneous four-bar linkage of the computing equation of the center, and then to VC + + to write a formula to known 3 long for the fourth actuator stroke length formula computing operation four-bar linkage, the angle of the instantaneous center coordinates and the instantaneous center trajectory data export into txt file format, through the MATLAB software package to txt file with the instantaneous center trajectory data to map out the coordinates of four-link instantaneous center of the mobile trajectory, seeking the best literature of the instantaneous center of a long trajectory of the four-bar linkage, Solid Works and then to interfere simulation, the design of the knee, mainly under the first bionic Knee base to connect to the cylinder at the top, as weight transfer and support patients with prosthetic knee flexion during the period of flexion and extension of the fixed side, so that the connecting tube for patients with weight transfer tube for the base (the third poles) with the patient in flexion and extension when - xiii - moving, and finally integrated air tube for filling with the gait cycle were deflated just enough structure and muscle induced by electrical stimulation compensation module, the soles of the feet back feeling the pressure sensing module and the compensation bionic knee institutions, of "an angry imitation controlled for tube-type electrical stimulation of knee prostheses." Therefore, this study not only the completion of the development of "an angry imitation controlled for tube-type electrical stimulation of knee prostheses," to provide electrical stimulation knee amputee, foot pressure sensor sensing feedback compensation, but also created a design more in line with the normal human knee joint movement trajectory of the instantaneous center institutions bionic knee. Key words: prostheses for extinguishers, knee prostheses, electrical stimulation, bionics, just enough

Over one million amputees are living in the United States with major lower limb loss (Ziegler-Graham et al. 2008). Lower limb amputation leads to the functional loss of the ankle plantar flexor muscles, which are important contributors to body support, forward propulsion, and leg swing initiation during walking (Neptune et al. 2001; Liu et al. 2006). Effective prosthetic component design is essential for successful rehabilitation of amputees to return to an active lifestyle by partially replacing the functional role of the ankle muscles. The series of experimental and computer simulation studies presented in this research showed that design characteristics of energy storage and return prosthetic ankles, specifically the elastic stiffness, significantly influence residual and intact leg ground reaction forces, knee joint moments, and muscle activity, thus affecting muscle output. These findings highlight the importance of proper prosthetic foot stiffness prescription for amputees to assure effective rehabilitation outcomes. The research also showed that the ankle muscles serve to stabilize the body during turning the center of mass. When amputees turn while supported by their prosthetic components, they rely more on gravity to redirect the center of mass than active muscle generation. This mechanism increases the risks of falling and identifies a need for prosthetic components and rehabilitation focused on increasing amputee stability during turning. A proper understanding of the effects of prosthetic components on amputee walking mechanics is critical to decreasing complications and risks that are prevalent among lower-limb amputees. The presented research is an important step towards reaching this goal.
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