Position and Weight Activated Passive Knee Mechanism

2015 ◽  
Author(s):  
Tyagi Ramakrishnan ◽  
Christina-Anne Lahiff ◽  
Asgard Kaleb Marroquin ◽  
Kyle B. Reed
Keyword(s):  
Human Gait ◽  
Low Friction ◽  
Human Knee ◽  
Prosthetic Knee ◽  
Normal Knee ◽  
Locking Mechanism ◽  
Angular Velocities ◽  
Normal Human ◽  
Prosthetic Knees ◽  
Simple Assembly

The human knee is a complex and robust system. It is the most important joint for human gait because of its immense load bearing ability. The loss of such an important joint often makes it difficult for a person to ambulate. Because of this and the resulting unnatural application of forces, many trans-femoral amputees develop an asymmetric gait that leads to future complications. Prosthetic knees are required to be well-designed to cope with all variabilities. There have been many prosthetic knee designs, some more complex than others. This paper describes the design and preliminary testing of a novel passive position and weight activated knee locking mechanism for use in lower limb prosthetics. This knee mechanism is designed to be a simple and economical alternative to existing knee mechanisms. The mechanism utilizes the dynamics of the user to lock the knee during stance and unlock during the swing phase. The presence of one moving component and a simple assembly makes this design a good base for customization. Results from testing the knee mechanism shows trends that are different from a normal human knee, which is to be expected. The prosthetic knee is designed to have low friction during swing of the shank and, hence, the flexion and extension angles and angular velocities are larger compared to a normal knee. The kinematics show a cyclic trend that is highly repeatable. Further refinement and testing can make this mechanism more efficient in mimicking a normal knee.

On Transfemoral Prosthetic Knee Design for Natural Human Knee Motion

2020 ◽  
Vol 13 (1) ◽  
pp. 49-59
Author(s):  
Wen-Tzong Lee ◽  
Kevin Russell ◽  
Raj S. Sodhi
Keyword(s):  
Design Process ◽  
Knee Flexion ◽  
Gait Cycle ◽  
Design Method ◽  
Human Gait ◽  
Motion Generation ◽  
Knee Motion ◽  
Human Knee ◽  
Prosthetic Knee ◽  
Position Data

Background: A transfemoral prosthetic knee is an artificial knee used by above-the-knee amputees. There are two major categories of transfemoral prosthetic knee designs: pin joint-based and polycentric designs. While pin joint-based knee designs only allow pure rotation of the knee, polycentric knee designs allow a combination of rotational and translational knee motion which is exhibited in natural knee motion. Objective: This work presents both the recently-patented design process and the resulting design of a polycentric transfemoral prosthetic knee that approximates natural spatial human knee motion during flexion and extension. Methods: The design process includes tibial motion acquisition, Revolute-Revolute-Spherical-Spherical linkage (or RRSS) motion generation, RRSS linkage axode generation and circle fitting. The polycentric transfemoral prosthetic knee design produced from this process includes a gear joint with a specific spatial orientation to approximate natural spatial human knee motion. Results: Using the design process, a polycentric transfemoral prosthetic knee was designed to replicate a group of five tibial positions over 37.5° of knee flexion (the amount of knee flexion in a standard human gait cycle) with a minimal structural error. Conclusion: The circular gear-based knee design accurately replicated natural spatial knee motion over the tibial position data given for a standard human gait cycle. The knee design method must be implemented over a broader sampling of tibial position data to determine if a circular gear-based knee design is consistently accurate.

Biomimetic Prosthetic Knee Using Antagonistic Muscle-Like Activation

2008 ◽  
Author(s):  
Ernesto C. Martinez-Villalpando ◽  
Jeff Weber ◽  
Grant Elliott ◽  
Hugh Herr
Keyword(s):  
Energy Consumption ◽  
Knee Prosthesis ◽  
Mechanical Work ◽  
Net Energy ◽  
Human Knee ◽  
Prosthetic Knee ◽  
Series Elasticity ◽  
Design And Implementation ◽  
Antagonistic Muscle ◽  
Prosthetic Knees

The majority of commercial prosthetic knees are passive in nature and therefore cannot replicate the positive mechanical work exhibited by the natural human knee in early and late stance. In contrast to traditional purely dissipative prosthetic knees, we propose a biomimetic active agonist-antagonist structure designed to reproduce both positive and negative work phases of the natural joint while using series elasticity to minimize net energy consumption. We present the design and implementation of the active knee prosthesis prototype.

Reduced cortical brain activity with the use of microprocessor-controlled prosthetic knees during walking

2018 ◽  
Vol 43 (3) ◽  
pp. 257-265 ◽  
Author(s):  
Saffran Möller ◽  
David Rusaw ◽  
Kerstin Hagberg ◽  
Nerrolyn Ramstrand
Keyword(s):  
Cognitive Processes ◽  
Lower Limb ◽  
Brain Activity ◽  
Control Group ◽  
Healthy Controls ◽  
Prosthetic Knee ◽  
Level Walking ◽  
Lower Limb Prosthesis ◽  
Prosthetic Knees ◽  
Limb Prosthesis

Background: Individuals using a lower-limb prosthesis indicate that they need to concentrate on every step they take. Despite self-reports of increased cognitive demand, there is limited understanding of the link between cognitive processes and walking when using a lower-limb prosthesis. Objective: The objective was to assess cortical brain activity during level walking in individuals using different prosthetic knee components and compare them to healthy controls. It was hypothesized that the least activity would be observed in the healthy control group, followed by individuals using a microprocessor-controlled prosthetic knee and finally individuals using a non-microprocessor-controlled prosthetic knee. Study design: Cross-sectional study. Methods: An optical brain imaging system was used to measure relative changes in concentration of oxygenated and de-oxygenated haemoglobin in the frontal and motor cortices during level walking. The number of steps and time to walk 10 m was also recorded. The 6-min walk test was assessed as a measure of functional capacity. Results: Individuals with a transfemoral or knee-disarticulation amputation, using non-microprocessor-controlled prosthetic knee ( n = 14) or microprocessor-controlled prosthetic knee ( n = 15) joints and healthy controls ( n = 16) participated in the study. A significant increase was observed in cortical brain activity of individuals walking with a non-microprocessor-controlled prosthetic knee when compared to healthy controls ( p < 0.05) and individuals walking with an microprocessor-controlled prosthetic knee joint ( p < 0.05). Conclusion: Individuals walking with a non-microprocessor-controlled prosthetic knee demonstrated an increase in cortical brain activity compared to healthy individuals. Use of a microprocessor-controlled prosthetic knee was associated with less cortical brain activity than use of a non-microprocessor-controlled prosthetic knee. Clinical relevance Increased understanding of cognitive processes underlying walking when using different types of prosthetic knees can help to optimize selection of prosthetic components and provide an opportunity to enhance functioning with a prosthesis.

scholarly journals Design of Biomechanical Legs with a Passive Toe Joint for Enhanced Human-like Walking

2017 ◽  
Vol 14 (2) ◽  
pp. 166 ◽  
Author(s):  
Riadh Zaier ◽  
A. Al-Yahmedi
Keyword(s):  
Design Procedure ◽  
Human Walking ◽  
Human Gait ◽  
Design Parameters ◽  
Sultan Qaboos University ◽  
Motion Trajectories ◽  
Normal Human ◽  
Working Principle ◽  
Mass Spring ◽  
Torsion Springs

This paper presents the design procedure of a biomechanical leg, with a passive toe joint, which is capable of mimicking the human walking. This leg has to provide the major features of human gait in the motion trajectories of the hip, knee, ankle, and toe joints. Focus was given to the approach of designing the passive toe joint of the biomechanical leg in its role and effectiveness in performing human like motion. This study was inspired by experimental and theoretical studies in the fields of biomechanics and robotics. Very light materials were mainly used in the design process. Aluminum and carbon fiber parts were selected to design the proposed structure of this biomechanical leg, which is to be manufactured in the Mechanical Lab of the Sultan Qaboos University (SQU). The capabilities of the designed leg to perform the normal human walking are presented. This study provides a noteworthy and unique design for the passive toe joint, represented by a mass-spring damper system, using torsion springs in the foot segment. The working principle and characteristics of the passive toe joint are discussed.  Four-designed cases, with different design parameters, for the passives toe joint system are presented to address the significant role that the passive toe joint plays in human-like motion. The dynamic motion that is used to conduct this comparison was the first stage of the stance motion. The advantages of the presence of the passive toe joint in gait, and its effect on reducing the energy consumption by the other actuated joints are presented and a comparison between the four-designed cases is discussed.

Normal Human Gait

2020 ◽  
pp. 1277-1298
Author(s):  
Freeman Miller
Keyword(s):  
Human Gait ◽  
Normal Human

Autonomic Computing in a Biomimetic Algorithm for Robots Dedicated to Rehabilitation of Ankle

2020 ◽  
pp. 955-968
Author(s):  
Euzébio D. de Souza ◽  
Eduardo José Lima II
Keyword(s):  
Autonomic Computing ◽  
Human Mobility ◽  
Lower Limbs ◽  
Human Gait ◽  
Locomotor System ◽  
Physiological Processes ◽  
Torque Generation ◽  
Reaction Forces ◽  
Normal Human ◽  
Robotic Devices

Human mobility is the key element of everyday life, its reduction or loss deeply affects daily activities. In assisted rehabilitation, robotic devices have focuses on the biomechanics of motor control. However, biomechanics does not study the neurological and physiological processes related to normal gait. Biomimetics combined with biomechanics, can generate a more efficient stimulation of the motor cortex and the locomotor system. The highest efficiency obtained through torque generation models, based on the physiological response of muscles and bones to reaction forces, together with control techniques based on autonomic computation. An autonomic control algorithm has a self-adjusting behaviour, ensuring patient safety and robot operation without the continuous monitoring of the physiotherapist. Thus, this work will identify the elements that characterize the physiological stimuli related to normal human gait, focusing on the ankle joint, aiming the development of biomimetic algorithms for robots for rehabilitation of the lower limbs.

The Spatial Order of Physeal Maturation in the Normal Human Knee Using Magnetic Resonance Imaging

2019 ◽  
Vol 39 (4) ◽  
pp. e318-e322 ◽  
Author(s):  
Adam Margalit ◽  
Ethan Cottrill ◽  
Derek Nhan ◽  
Lingjia Yu ◽  
Xin Tang ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Resonance Imaging ◽  
Spatial Order ◽  
Human Knee ◽  
Normal Human

MRI Analysis of Anteroposterior Stability in the Normal Human Knee

2009 ◽  
Author(s):  
Sally Arno ◽  
Rachel Forman ◽  
Philip Glassner ◽  
Ravinder Regatte ◽  
Peter S. Walker
Keyword(s):  
Shear Force ◽  
Medial Meniscus ◽  
Sagittal Plane ◽  
The Body ◽  
Lateral Side ◽  
Human Knee ◽  
Medial Side ◽  
Normal Human ◽  
Femoral Rollback ◽  
High Range

During activities the knee experiences compressive forces caused by the weight of the body and muscle forces. However, there is also an anterior shear force pushing the femur forwards on the tibia. It is likely to be important to the feeling of stability that the shear force is resisted so as to limit the anterior femoral displacement. The dished bearing surface of the medial tibial compartment in combination with the medial meniscus may well perform this function. In contrast, the lateral tibial surface is convex in the sagittal plane and the meniscus is too mobile to offer any anteroposterior (AP) restraint. Therefore, we hypothesize that if an anterior or posterior force is applied to the femur relative to the tibia, AP stability is provided by the medial side, while the lateral side allows for femoral rollback to facilitate a high range of flexion. At any flexion angle, rotational laxity will occur about a point on the medial side.

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