Academic literature on the topic 'Powered knee prosthese'
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Journal articles on the topic "Powered knee prosthese"
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Shin, Hyunjun, Jinkuk Park, Huitae Lee, Sungyoon Jung, Mankee Jeon, and Sehoon Park. "Selective Passive/Active Switchable Knee Prosthesis Based on Multifunctional Rotary Hydraulic Cylinder for Transfemoral Amputees." Actuators 12, no. 3 (March 9, 2023): 118. http://dx.doi.org/10.3390/act12030118.
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Significant advances have been made in prostheses with the aim of enhancing the quality of life for transfemoral amputees. While commercially available transfemoral prostheses mainly focus on the developing passive prostheses that act only as dampers, academic research is centered round powered prostheses that can provide net-positive knee torque. Although recent active-powered prostheses have made excellent progress in terms of weight and battery life, it remains unclear if these prostheses can be effectively used in everyday life. This study presents a rotary hybrid prosthesis based on the combination of a multifunctional rotary hydraulic cylinder that is designed to operate as a brake, clutch, and damper with a 100 W active motor system. This prosthesis enables long-term level ground walking while supplying active power as needed. The passive and active components of this hybrid prosthesis are designed such that they can be decoupled when operated independently, allowing for quick switching between passive and active modes in 50–100 ms. The study outlines the aims and procedures for the design of rotary hybrid prostheses, as well as the feasibility tests for each module and the amputee’s clinical test on the developed knee prosthesis.
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Bhakta, Krishan, Jonathan Camargo, Pratik Kunapuli, Lee Childers, and Aaron Young. "Impedance Control Strategies for Enhancing Sloped and Level Walking Capabilities for Individuals with Transfemoral Amputation Using a Powered Multi-Joint Prosthesis." Military Medicine 185, Supplement_1 (December 9, 2019): 490–99. http://dx.doi.org/10.1093/milmed/usz229.
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ABSTRACT Introduction Powered prostheses are a promising new technology that may help people with lower-limb loss improve their ability to perform locomotion tasks. Developing active prostheses requires robust design methodologies and intelligent controllers to appropriately provide assistance to the user for varied tasks in different environments. The purpose of this study was to validate an impedance control strategy for a powered knee and ankle prosthesis using an embedded sensor suite of encoders and a six-axis load cell that would aid an individual in performing common locomotion tasks, such as level walking and ascending/descending slopes. Materials and Methods Three amputees walked on a treadmill and four amputees walked on a ramp circuit to test whether a dual powered knee and ankle prosthesis could generate appropriate device joint kinematics across users. Results Investigators found that tuning 2–3 subject-specific parameters per ambulation mode was necessary to render individualized assistance. Furthermore, the kinematic profiles demonstrate invariance to walking speeds ranging from 0.63 to 1.07 m/s and incline/decline angles ranging from 7.8° to 14°. Conclusion This work presents a strategy that requires minimal tuning for a powered knee & ankle prosthesis that scales across a nominal range of both walking speeds and ramp slopes.
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Eilenberg, Michael F., Jiun-Yih Kuan, and Hugh Herr. "Development and Evaluation of a Powered Artificial Gastrocnemius for Transtibial Amputee Gait." Journal of Robotics 2018 (2018): 1–15. http://dx.doi.org/10.1155/2018/5951965.
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Existing robotic transtibial prostheses provide only ankle joint actuation and do not restore biarticular function of the gastrocnemius muscle. This paper presents the first powered biarticular transtibial prosthesis, which is a combination of a commercial powered ankle-foot prosthesis and a motorized robotic knee orthosis. The orthosis is controlled to emulate the human gastrocnemius based on neuromuscular models of matched nonamputees. Together with the ankle-foot prosthesis, the devices provide biarticular actuation. We evaluate differences between this biarticular condition and a monoarticular condition with the orthosis behaving as a free-joint. Six participants with transtibial amputation walk with the prosthesis on a treadmill while motion, force, and metabolic data are collected and analyzed for differences between conditions. The biarticular prosthesis reduces affected-side biological knee flexion moment impulse and hip positive work during late-stance knee flexion, compared to the monoarticular condition. The data do not support our hypothesis that metabolism decreases for all participants, but some participants demonstrate large metabolic reductions with the biarticular condition. These preliminary results suggest that a powered artificial gastrocnemius may be capable of providing large metabolic reductions compared to a monoarticular prosthesis, but further study is warranted to determine an appropriate controller for achieving more consistent metabolic benefits.
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Eilenberg, Michael F., Ken Endo, and Hugh Herr. "Biomechanic and Energetic Effects of a Quasi-Passive Artificial Gastrocnemius on Transtibial Amputee Gait." Journal of Robotics 2018 (2018): 1–12. http://dx.doi.org/10.1155/2018/6756027.
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State-of-the-art transtibial prostheses provide only ankle joint actuation and thus do not provide the biarticular function of the amputated gastrocnemius muscle. We develop a prosthesis that actuates both knee and ankle joints and then evaluate the incremental effects of this prosthesis as compared to ankle actuation alone. The prosthesis employs a quasi-passive clutched-spring knee orthosis, approximating the largely isometric behavior of the biological gastrocnemius, and utilizes a commercial powered ankle-foot prosthesis for ankle joint functionality. Two participants with unilateral transtibial amputation walk with this prosthesis on an instrumented treadmill, while motion, force, and metabolic data are collected. Data are analyzed to determine differences between the biarticular condition with the activation of the knee orthosis and the monoarticular condition with the orthosis behaving as a free-joint. As hypothesized, the biarticular system is shown to reduce both affected-side knee and hip moment impulse and positive mechanical work in both participants during the late stance knee flexion phase of walking, compared to the monoarticular condition. The metabolic cost of walking is also reduced for both participants. These very preliminary results suggest that biarticular functionality may provide benefits beyond even those of the most advanced monoarticular prostheses.
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Lenzi, Tommaso, Marco Cempini, Levi Hargrove, and Todd Kuiken. "Design, development, and testing of a lightweight hybrid robotic knee prosthesis." International Journal of Robotics Research 37, no. 8 (July 2018): 953–76. http://dx.doi.org/10.1177/0278364918785993.
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We present a lightweight robotic knee prosthesis with a novel hybrid actuation system that enables passive and active operation modes. The proposed hybrid knee uses a spring-damper system in combination with an electric motor and transmission system, which can be engaged to provide a stair ambulation capability. In comparison to fully powered prostheses that power all ambulation activities, a hybrid knee prosthesis can achieve significant weight reduction by focusing the design of the actuator on a subset of activities without losing the ability to produce equivalent torque and mechanical power in the active mode. The hybrid knee prototype weighs 1.7 kg, including battery and control, and can provide up to 125 Nm of repetitive torque. Experiments with two transfemoral amputee subjects show that the proposed hybrid knee prosthesis can support walking on level ground in the passive mode, as well as stair ambulation with a reciprocal gait pattern in the active mode.
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Mendez, Joel, Sarah Hood, Andy Gunnel, and Tommaso Lenzi. "Powered knee and ankle prosthesis with indirect volitional swing control enables level-ground walking and crossing over obstacles." Science Robotics 5, no. 44 (July 22, 2020): eaba6635. http://dx.doi.org/10.1126/scirobotics.aba6635.
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Powered prostheses aim to mimic the missing biological limb with controllers that are finely tuned to replicate the nominal gait pattern of non-amputee individuals. Unfortunately, this control approach poses a problem with real-world ambulation, which includes tasks such as crossing over obstacles, where the prosthesis trajectory must be modified to provide adequate foot clearance and ensure timely foot placement. Here, we show an indirect volitional control approach that enables prosthesis users to walk at different speeds while smoothly and continuously crossing over obstacles of different sizes without explicit classification of the environment. At the high level, the proposed controller relies on a heuristic algorithm to continuously change the maximum knee flexion angle and the swing duration in harmony with the user’s residual limb. At the low level, minimum-jerk planning is used to continuously adapt the swing trajectory while maximizing smoothness. Experiments with three individuals with above-knee amputation show that the proposed control approach allows for volitional control of foot clearance, which is necessary to negotiate environmental barriers. Our study suggests that a powered prosthesis controller with intrinsic, volitional adaptability may provide prosthesis users with functionality that is not currently available, facilitating real-world ambulation.
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Shen, Kaixin, Qing Wei, Yongshang Huang, and Hongxu Ma. "Continuous instinct control for powered knee-ankle prostheses." MATEC Web of Conferences 309 (2020): 04011. http://dx.doi.org/10.1051/matecconf/202030904011.
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In order to improve the life quality of lower extremity amputees, many researchers have studied the powered knee-ankle prosthesis. Various parameters must necessarily be adjusted for the finite state machine impedance model method. Hybrid zero-dynamic (HZD) assumptions are ideal, and with this method measurement information of existing sensors can be limited. The virtual constraint method offers better comprehensive performance at present and can realize the continuous control for the whole gait cycle. The problem with virtual constraint is mainly the selection of phase variables. The joint trajectory of the virtual constraint is derived from a healthy individual, but the joint trajectory of the amputee’s normal walking is difficult to obtain. In response to the above problems, this paper proposes an instinctive human joint trajectory, selecting the phase variable associated with the hip joint angle and angular velocity. The Fourier transform solves the expression of the joint trajectory, and the virtual constraint unifies the control method of the entire gait cycle. The simulation results prove the feasibility of the scheme.
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Liu, Ming, Philip Datseris, and He Helen Huang. "A Prototype for Smart Prosthetic Legs-Analysis and Mechanical Design." Advanced Materials Research 403-408 (November 2011): 1999–2006. http://dx.doi.org/10.4028/www.scientific.net/amr.403-408.1999.
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In this paper, we designed a prototype of powered above-knee prosthesis. Compared with other prototypes available in the literature, our designed prosthetic leg employs a redundant actuator concept to overcome the challenge faced by the single-motor transmission systems. The redundant actuator also enables the prosthesis to be partially functional when the prosthesis loses power. Finally, in order to provide optimal control parameters for designed above-knee prosthesis to perform a smooth level-ground walking task, an inverse dynamic model based on Kane’s method is constructed.
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Wu, Molei, Md Rejwanul Haque, and Xiangrong Shen. "Obtaining Natural Sit-to-Stand Motion with a Biomimetic Controller for Powered Knee Prostheses." Journal of Healthcare Engineering 2017 (2017): 1–6. http://dx.doi.org/10.1155/2017/3850351.
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Standing up from a seated position is a common activity in people’s daily life. However, for transfemoral (i.e., above-knee) amputees fitted with traditional passive prostheses, the sit-to-stand (STS) transition is highly challenging, due to the inability of the prosthetic joints in generating torque and power output. In this paper, the authors present a new STS control approach for powered lower limb prostheses, which is able to regulate the power delivery of the prosthetic knee joint to obtain natural STS motion similar to that displayed by healthy subjects. Mimicking the dynamic behavior of the knee in the STS, a unified control structure provides the desired control actions by combining an impedance function with a time-based ramp-up function. The former provides the gradual energy release behavior desired in the rising phase, while the latter provides the gradual energy injection behavior desired in the loading phase. This simple and intuitive control structure automates the transition between the two phases, eliminating the need for explicit phase transition and facilitating the implementation in powered prostheses. Human testing results demonstrated that this new control approach is able to generate a natural standing-up motion, which is well coordinated with the user’s healthy-side motion in the STS process.
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Lawson, Brian E., and Michael Goldfarb. "Impedance & Admittance-Based Coordination Control Strategies for Robotic Lower Limb Prostheses." Mechanical Engineering 136, no. 09 (September 1, 2014): S12—S17. http://dx.doi.org/10.1115/9.2014-sep-6.
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This article presents and compares two different control systems for a powered knee and ankle prosthesis for transfemoral amputees, which were constructed to provide the user a safe, intuitive, and well-coordinated interaction with the prosthesis. The piecewise-passive impedance (PPI) controller utilizes only impedance-like behaviors, while the second – a hybrid impedance-admittance (HIA) controller – utilizes both impedance-like and admittance-like behaviors in a hybrid approach. The HIA approach maintains many of the desirable characteristics of the PPI controller while also reducing the number of selectable control parameters. The HIA approach essentially incorporates the PPI control structure during the early and middle stance phases of gait, and a trajectory tracking control approach in terminal stance and swing. These controllers were implemented on a powered knee and ankle prosthesis and tested in walking trials by a transfemoral amputee. Data from these trials indicate that both controllers achieve comparable performance with respect to healthy subject data, despite some substantial structural differences between the two.
Dissertations / Theses on the topic "Powered knee prosthese"
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Mooney, Luke Matthewson. "The use of series compliance and variable transmission elements in the design of a powered knee prosthesis." Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/92190.
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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.
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Stentzel, Christian, Volker Waurich, and Frank Will. "Miniature hydraulics for a mechatronic lower limb prosthesis." Technische Universität Dresden, 2020. https://tud.qucosa.de/id/qucosa%3A71230.
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In Germany alone, 10,000 to 12,000 transfemoral amputations occur every year. Persistent rehabilitation efforts and advanced medical devices like prosthetic knee joints are crucial to reintegrating amputees into daily life successfully. Modern knee joints represent a highly integrated mechatronic system including special kinematics, a lightweight design, various sensors, microprocessors and complex algorithms to control a damping system in the context of the given situation. A knee joint is a passive system and normally has no actuator for an active movement. To enable a natural gait pattern, dampers decelerate the swinging speed of the prosthesis depending on the walking speed and situation. The invention of a novel knee joint called VarioKnie provides two kinematics - a monocentric and a polycentric one. Both kinematics have diametrical advantages and the user can choose the preferred setting through an electromechanical switching unit. With this knee joint in mind, a special hydraulic damper is developed to support both kinematics. Requirements and technical data are provided in the present paper. State of art are microprocessor-controlled knee joints with only one kinematic and either a hydraulic, a pneumatic, or a rheological damper.
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Warner, Holly E. "Simulation and Control at the Boundaries Between Humans and Assistive Robots." Cleveland State University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=csu1577719990967925.
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Shiu, Chi Feng, and 徐啟峰. "Development of Power Assisted Above Knee Prosthesis with Proprioception Compensation and Coordinated Control." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/33095008774253775679.
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碩士長庚大學
醫療機電工程研究所
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The amputee patients accompany with muscle power insufficient and proprioception losing because their knee joint construction and major muscle fascicle which control knee flexion or extension were cut. Therefore, amputee patients need to swing their stump to make knee joint flexion or extension. These repeated motions could not swing to target knee angle stably and precisely. In this study, in order to breakthrough these drawbacks, a prosthesis system with power assisted, mechanism design, proprioception compensation was developed and verified. There were static functional verification and dynamic functional verification in this study. In the static functional verification, the linear ruler was used to measure the stroke of actuator developed in this study. Besides, the digital level meter was used to assess the angle control verification. These measured results were compared with targeted values. The mean error of stroke was 0.023±0.175mm, and the mean error of angle was 0.005±0.074°. In the dynamic functional verification, the proprioception compensation and coordinate control modules were considered in the level walking experiments, the differences between affected side and unaffected side were used to evaluate the coordinate control efficiency. The mean maximum flexion angle error was 0.748±0.898° and the percentage error was 1.968%. In addition, the mean delay time was 0.025±0.022 seconds. The experimental results showed that the amputee system developed in this study could provide coordinate level walking for amputee.
Book chapters on the topic "Powered knee prosthese"
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Rupar, Miljan, Zlata Jelačić, Remzo Dedić, and Adisa Vučina. "Power and Control System of Knee and Ankle Powered Above-Knee Prosthesis." In Lecture Notes in Networks and Systems, 211–16. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-90893-9_26.
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Rupar, Miljan, Adisa Vučina, and Remzo Dedić. "Knee and Ankle Powered Above-Knee Prosthesis Design and Development." In IFMBE Proceedings, 625–29. Singapore: Springer Singapore, 2018. http://dx.doi.org/10.1007/978-981-10-9038-7_116.
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Jelačić, Zlata, and Remzo Dedić. "Real Time Control of Above-Knee Prosthesis with Powered Knee and Ankle Joints." In New Technologies, Development and Application II, 278–84. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-18072-0_33.
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Chen, Guoxing, Zuojun Liu, Lingling Chen, and Peng Yang. "Control of Powered Knee Joint Prosthesis Based on Finite-State Machine." In Proceedings of the 2015 Chinese Intelligent Automation Conference, 395–403. Berlin, Heidelberg: Springer Berlin Heidelberg, 2015. http://dx.doi.org/10.1007/978-3-662-46463-2_40.
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Tessari, Federico, Renato Galluzzi, Nicola Amati, Andrea Tonoli, Matteo Laffranchi, and Lorenzo De Michieli. "Design and Testing of a Fully-Integrated Electro-Hydrostatic Actuator for Powered Knee Prostheses." In Biosystems & Biorobotics, 95–100. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-69547-7_16.
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"Intelligent Above-Knee Prosthesis." In Fluid Power, 171–72. CRC Press, 1993. http://dx.doi.org/10.4324/9780203223475-48.
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Jelačić, Zlata, Remzo Dedić, and Haris Dindo. "Hydraulic power and control system." In Active Above-Knee Prosthesis, 63–108. Elsevier, 2020. http://dx.doi.org/10.1016/b978-0-12-818683-1.00003-2.
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Milanezi de Andrade, Rafhael, André Palmiro Storch, Lucas de Amorim Paulo, Antônio Bento Filho, Claysson Bruno Santos Vimieiro, and Marcos Pinotti. "Transient Thermal Analysis of a Magnetorheological Knee for Prostheses and Exoskeletons during Over-Ground Walking." In Heat Transfer - Design, Experimentation and Applications [Working Title]. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.95372.
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Proper knee movement is essential for accomplishing the mobility daily tasks such as walking, get up from a chair and going up and down stairs. Although the technological advances in active knee actuators for prostheses and exoskeletons to help impaired people in the last decade, they still present several usage limitations such as overweight or limited mechanical power and torque. To address such limitations, we developed the Active Magnetorheological Knee (AMRK) that comprises a Motor Unit (MU), which is a motor-reducer (EC motor and Harmonic Drive) and a MR clutch, that works in parallel to a magnetorheological (MR) brake. Magnetorheological fluids, employed in the MR clutch and brake, are smart materials that have their rheological properties controlled by an induced magnetic field and have been used for different purposes. With this configuration the actuator can work as a motor, clutch or brake and can perform similar movements than a healthy knee. However, the stability, control, and life of magnetorheological fluids critically depend on the working temperature. By reaching a certain temperature limit, the fluid additives quickly deteriorate, leading to irreversible changes of the MR fluid. In this study, we perform a transient thermal analysis of the AMRK, when it is used for walking over-ground, to access possible fluid degradation and user’s discomfort due overheating. The resulting shear stress in the MR clutch and brake generates heat, increasing the fluid temperature during the operation. However, to avoid overheating, we proposed a mode of operation for over-ground walking aiming to minimize the heat generation on the MR clutch and brake. Other heat sources inside the actuator are the coils, which generate the magnetic fields for the MR fluid, bearings, EC motor and harmonic drive. Results show that the MR fluid of the brake can reach up to 31°C after a 6.0 km walk, so the AMRK can be used for the proposed function without risks of fluid degradation or discomfort for the user.
Conference papers on the topic "Powered knee prosthese"
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Lenzi, Tommaso, Marco Cempini, Levi Hargrove, and Todd Kuiken. "Hybrid Actuation Systems for Lightweight Transfemoral Prostheses." In 2017 Design of Medical Devices Conference. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/dmd2017-3398.
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Lower-limb amputation affects the ambulation ability and quality of life of about 600,000 individuals in the United States alone1. Individuals with transfemoral amputation typically walk slower, expend more energy, and have a higher risk of falls than able-bodied individuals2. Ambulation activities such as climbing ramps or stairs or standing up from a seated position are much more difficult than for able-bodied persons. Advances in prosthetic technologies are needed to improve the ambulation ability of above-knee amputees. Passive knee prostheses are lightweight, robust, and quiet, but can only perform activities with dissipative dynamics. Powered prostheses3 overcome this limitation by motorizing the prosthetic joints throughout the entire day, thus enabling the achievement of more activities. However, the prosthesis actuator must then accommodate a wide range of speed and torque to support the various activities, plus provide power over the course of the entire day. Consequently, powered prostheses provide the ability to perform more tasks at the expense of substantial weight, noise, and battery life, which in turn affect their acceptability and clinical viability. To address these shortcomings, we propose a hybrid actuation design for prosthetic knees. The proposed hybrid actuation system uses a motor, transmission, and control only for those activities requiring net-positive mechanical energy, such as climbing on stairs and ramps or performing sit-to-stand transfers. For non-positive mechanical energy tasks, such as standing and walking, the motor and transmission are mechanically disconnected, and passive knee components are used alone, thus achieving improved joint dynamics, and avoiding any electrical energy consumption.
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Wu, Molei, Md Rejwanul Haque, and Xiangrong Shen. "Sit-to-Stand Control of Powered Knee Prostheses." In 2017 Design of Medical Devices Conference. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/dmd2017-3507.
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Standing from a seated position is a common, yet dynamically challenging task. Due to the vertical ascent of the body center of gravity, sit-to-stand (STS) transition requires high torque output from the knee. As a result, STS transition poses a major barrier to the mobility of individuals with lower-limb issues, including the transfemoral (TF, also known as above-knee) amputees. A study showed that unilateral TF amputees suffer from high asymmetry in ground reaction forces (53∼69%) and knee moments (110∼124%), while the asymmetry for healthy controls is less than 7% [1]. Note that, although a powered TF prosthesis (Power Knee™) was used in this study, it generated resistance in the STS and thus produced similar results as the passive devices. The inability of existing prostheses in generating knee torque and regulating the torque delivery in the STS seriously affects the mobility of TF amputees in their daily life. Motivated by this issue, researchers have developed numerous powered TF prostheses (e.g., Vanderbilt powered TF prostheses [2]). These devices are able to generate torque and power for challenging tasks such as STS transition. Making full use of such capability, however, requires an effective controller. Currently, walking control for powered prostheses has been well established, but STS control is much less investigated. Varol et al. developed a multi-mode TF prosthesis controller, in which STS is treated as a transitional motion between sitting and standing states [2]. However, no details were provided on the rationale of the STS controller structure or the determination of the control parameters. In this paper, a new prosthesis control approach is presented, which regulates the power and torque delivery in the STS process. Inspired by the biomechanical behavior of the knee in the STS motion, the new controller provides two desired functions (gradual loading of the knee at the beginning, and automatic adjustment of the knee torque according to motion progress) with a single equation. Combined with a simple yet reliable triggering condition, the proposed control approach is able to provide natural STS motion for the powered knee prosthesis users.
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Wu, Molei, and Xiangrong Shen. "Walking-Stair Climbing Control for Powered Knee Prostheses." In ASME 2016 Dynamic Systems and Control Conference. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/dscc2016-9895.
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Recent progresses in powered lower-limb prostheses have the potential of enabling amputee users to conduct energetically demanding locomotive tasks, which are usually beyond the capability of traditional unpowered prostheses. Realizing such potential, however, requires responsive and reliable control of the power provided by prosthetic joints. In this paper, an integrated walking-stair climbing control approach is presented for transfemoral prostheses with powered knee joints. Leveraging the similarities between walking and stair climbing, this new approach adopts the general finite-state impedance control framework. Furthermore, important modifications are introduced to model the biomechanical characteristics that are beyond the capability of standard impedance control. The transition between the walking and stair-climbing modes is triggered through the real-time measurement of the spatial orientation of the user’s thigh, which provides a reliable indicator of the user’s intention of making such transition. This new control approach has been implemented on a powered knee prosthesis, and its effectiveness was demonstrated in human subject testing.
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Wu, Molei, Saroj Thapa, Md Rejwanul Haque, and Xiangrong Shen. "Toward a Low-Cost Modular Powered Transtibial Prosthesis: Initial Prototype Design and Testing." In 2017 Design of Medical Devices Conference. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/dmd2017-3504.
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In human walking, the ankle plays an important role of supplying power needed for the forward motion [1]. However, traditional transtibial (TT, a.k.a. below-knee, BK) prostheses are passive, lacking the ability of generating power output in the prosthetic ankle. Consequently, amputees fitted with such prostheses suffer from multiple issues (asymmetric gait, greater metabolic energy expenditure, etc.). To address such issues, researchers have explored various technical approaches to develop powered TT prostheses. Hydraulics and pneumatics have been attempted, leveraging the high power density with these actuators (e.g. [2]). Electromagnetic actuators were used more extensively with its technological maturity and convenience in packaging. Typical examples include the multiple prototypes developed by the MIT Biomechatronics Group (e.g., [3]), the SPARKy project, and the Vanderbilt Transtibial Prosthesis. The TT prostheses mentioned above all include powered ankle joints to provide power for the users’ locomotion. However, cost and complexity are often given lower priority than performance in the development of such devices. Powered TT prosthesis is a typical low-volume product from a commercial perspective, and the resulting high cost is a major hurdle for the large-scale adoption among amputee users. General robotic components (motors, gearsets, etc.), in contrary, are produced in large quantities with relatively low prices. Such contrast is the major inspiration for this work: the goal is to develop a modular powered TT prosthesis based on low-cost commercial robotic components while minimizing the complexity in manufacturing and assembly.
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Wu, Sai-Kit, Garrett Waycaster, and Xiangrong Shen. "Active Knee Prosthesis Control With Electromyography." In ASME 2010 Dynamic Systems and Control Conference. ASMEDC, 2010. http://dx.doi.org/10.1115/dscc2010-4068.
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This paper describes a new electromyography (EMG) based control approach for powered above-knee prostheses. In the proposed control approach, the EMG signals are utilized as the direct control commands to the prosthesis, and thus enable the volitional control by the wearer, not only for locomotive functions, but for arbitrary motion as well. To better integrate the AK prosthesis into the rest of the human body, the control approach incorporates a human motor control mechanism-inspired ‘active-reactive’ model, which combines an active control component that reflects the wearer’s motion intention, with a reactive control component that implements the controllable impedance critical to the safe and stable interaction with the environment. The effectiveness of the proposed control approach was demonstrated through the experimental results for arbitrary free swing and level walking.
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Lura, Derek J., M. Jason Highsmith, Stephanie L. Carey, and Rajiv V. Dubey. "Kinetic Differences in a Subject With Two Different Prosthetic Knees While Performing Sitting and Standing Movements." In ASME 2008 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2008. http://dx.doi.org/10.1115/sbc2008-193045.
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Advanced prostheses are currently being sold in consumer markets. The development of these advanced prostheses is largely a result of a better understanding of the biomechanics of human locomotion [1]. Powered and microprocessor controlled prostheses are offering better performance in a variety of movements and in the gait cycle. However the focus in lower limb prosthetics has been largely on locomotion (e.g. walking, stair gait and running). This study focuses on the sit and stand cycles of an individual with an Otto Bock C-leg and an Ossur Power Knee prosthesis, comparing his ability to utilize each prosthesis and comparing his cycle to that of a healthy (non-amputee) control subject. This study is part of a larger ongoing study of the sit and stand cycles seen in a large population of unilateral transfemoral prosthetic users of various kinds. The purpose of this study is to compare the difference in method of standing, and assistance provided by the prosthesis. With the knowledge gained from this study we hope to better understand the biomechanics of the sit and stand cycles, leading to better prostheses in the future.
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Laschowski, Brock, and Jan Andrysek. "Electromechanical Design of Robotic Transfemoral Prostheses." In ASME 2018 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/detc2018-85234.
Full textAbstract:
Alongside promising advances in biomechatronics, the following research presents the first documented investigation reviewing the electromechanical system designs of energetically-powered (i.e., robotic) prostheses for patients with transfemoral amputations. The technical review begins with examining the material and mechanical designs, and electrical batteries incorporated into robotic transfemoral prostheses. The actuation systems have encompassed electromagnetic actuators (i.e., occasionally featuring series elastic elements), pneumatic actuators (i.e., pneumatic cylinders and pneumatic artificial muscles), and hydraulic actuators. Various wearable sensors have been utilized to provide closed-loop feedback control, including electromechanical sensors, surface electromyography, and bioinspired machine vision systems. The Össur Power Knee (i.e., the only commercially-available powered transfemoral prosthesis) is additionally discussed. The technical review concludes with suggesting prospective future directions for innovation, specifically lower-limb prostheses capability of electrical energy regeneration.
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Wu, Sai-Kit, Garrett Waycaster, and Xiangrong Shen. "Control of Active Above-Knee Prostheses Through Electromyography." In ASME 2010 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2010. http://dx.doi.org/10.1115/sbc2010-19505.
Full textAbstract:
This paper describes a new electromyography (EMG) based control approach for powered above-knee prostheses. In the proposed control approach, the EMG signals are utilized as the direct control commands to the prosthesis, and thus enable the volitional control by the wearer, not only for locomotive functions, but for arbitrary motion as well. To better integrate the AK prosthesis into the rest of the human body, the control approach incorporates a human motor control mechanism-inspired ‘active-passive’ model, which combines an active control component that reflects the wearer’s motion intention, with a passive control component that implements the controllable impedance critical to the safe and stable interaction with the environment. The effectiveness of the proposed control approach was demonstrated through the experimental results for arbitrary free swing and level walking.
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Sup, Frank C., and Michael Goldfarb. "Design of a Pneumatically Actuated Transfemoral Prosthesis." In ASME 2006 International Mechanical Engineering Congress and Exposition. ASMEDC, 2006. http://dx.doi.org/10.1115/imece2006-15707.
Full textAbstract:
This paper describes the design of an above-knee prosthesis with actively powered knee and ankle joints, both of which are actuated via pneumatic actuators. The prosthesis serves as a laboratory test-bed to validate the design and develop of control interfaces for future self-contained versions (i.e., with onboard hot-gas power and computing), and therefore includes a tether for both pneumatic power and control. The prototype prosthesis provides the full range of motion for both the knee and ankle joints while providing 100% of the knee torque required for fast cadence walking and stair climbing and 76% and 100%, respectively, of the ankle torque required for fast cadence walking and for stair climbing, based on the torques required by a healthy 75 kg subject. The device includes sensors to measure knee and ankle torque and position, in addition to a load cell that measures the interaction force and (sagittal and frontal planes) moments between the user and device.
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Narang, Yashraj S., and Amos G. Winter. "Effects of Prosthesis Mass on Hip Energetics, Prosthetic Knee Torque, and Prosthetic Knee Stiffness and Damping Parameters Required for Transfemoral Amputees to Walk With Normative Kinematics." In ASME 2014 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/detc2014-35065.
Full textAbstract:
We quantify how the hip energetics and knee torque required for an above-knee prosthesis user to walk with the kinematics of able-bodied humans vary with the inertial properties of the prosthesis. We also select and optimize passive mechanical components for a prosthetic knee to accurately reproduce the required knee torque. Previous theoretical studies have typically investigated the effects of prosthesis inertial properties on energetic parameters by modifying both mass and mass distribution of the prosthesis and computing kinetic and energetic parameters only during swing. Using inverse dynamics, we determined the effects of independently modifying mass and mass distribution of the prosthesis, and we computed parameters during both stance and swing. Results showed that reducing prosthesis mass significantly affected hip energetics, whereas reducing mass distribution did not. Reducing prosthesis mass to 25% of the mass of a physiological leg decreased peak stance hip power by 26%, average swing hip power by 74%, and absolute hip work over the gait cycle by 22%. Previous studies have also typically optimized prosthetic knee components to reproduce the knee torque generated by able-bodied humans walking with normative kinematics. However, because the prosthetic leg of an above-knee prosthesis user weighs significantly less than a physiological leg, the knee torque required for above-knee prosthesis users to walk with these kinematics may be significantly different. Again using inverse dynamics, it was found that changes in prosthesis mass and mass distribution significantly affected this required torque. Reducing the mass of the prosthesis to 25% of the mass of the physiological leg increased peak stance torque by 43% and decreased peak swing torque by 76%. The knee power required for an above-knee prosthesis user to walk with the kinematics of able-bodied humans was analyzed to select passive mechanical components for the prosthetic knee. The coefficients of the components were then optimized to replicate the torque required to walk with the kinematics of able-bodied humans. A prosthetic knee containing a single linear spring and two constant-force dampers was found to accurately replicate the targeted torque (R2=0.90 for a typical prosthesis). Optimal spring coefficients were found to be relatively insensitive to mass alterations of the prosthetic leg, but optimal damping coefficients were sensitive. In particular, as the masses of the segments of the prosthetic leg were altered between 25% and 100% of able-bodied values, the optimal damping coefficient of the second damper varied by 330%, with foot mass alterations having the greatest effect on its value.