Modeling and Simulation of an Assistive Exoskeleton Leg System with Knee Osteoarthritis and Quadriceps Weakness

2022 ◽  
Author(s):  
Mehmet Iscan ◽  
Cuneyt Yilmaz ◽  
Berkem Vural ◽  
Huseyin Eken
Keyword(s):  
Knee Osteoarthritis ◽  
Feedback Linearization ◽  
Gait Cycle ◽  
Minimum Energy ◽  
Human Locomotion ◽  
Human Gait ◽  
Quadriceps Weakness ◽  
The Common ◽  
Adequate Data

Abstract The most common human locomotion problems such as quadriceps weakness, knee osteoarthritis can be healed up by using exoskeleton mechanisms with proper control systems. However, these kinds of abnormalities cannot be easily modeled in terms of engineering perspectives due to a lack of adequate data or unknown dynamics. Also, nature always seeks minimum energy as well as biology which means that the unknown dynamics can be built by using this phenomenon. In this study, a new system dynamic model had been involved in designing a simple single-legged exoskeleton robot mechanism and its control system to assist partially disabled individuals to improve their quality of locomotion. To determine the specific features of the human gait disorders to interpret their nature in the computer-aided simulation environment, knee osteoarthritis and quadriceps weakness, which are the common types of such problems, have been chosen as the main interests for this study. By using the lower limb model with anthropometric data, the simulations of disorders have been realized on MATLAB Simscape environment which enables us to model the entire exoskeleton system with the 3D parts of the human body. A model of a leg with the disorder was able to be obtained with the utilization of feedback linearization which is one of the examples of minimum principles in the control theory. A proper gait cycle is achieved with the exoskeleton application and separately for the leg, with approximately 10 deg deviation from the natural property in knee flexion. Finally, it can be seen that the system conversion into such problematic cases with or without an exoskeleton system is accomplished.

Estimation of Metabolical Costs for Human Locomotion

2005 ◽  
Author(s):  
Werner Schiehlen ◽  
Marko Ackermann
Keyword(s):  
Degrees Of Freedom ◽  
Inverse Dynamics ◽  
Sagittal Plane ◽  
Human Locomotion ◽  
Human Gait ◽  
Joint Torques ◽  
Gait Quality ◽  
Analysis Laboratory ◽  
Muscle Models

Metabolical energy is the chemical energy consumed by skeletal muscles to generate force. This quantity is useful to understand the comfort of human gait and to evaluate, in terms of effort required, the performance of devices or therapies designed to improve gait quality of persons presenting gait disorders. Firstly, this paper presents the frequently used estimations of energy expenditure based lonely on joint torques and mechanical costs obtained by inverse dynamics of passive and active walking devices. Secondly, a more advanced approach is discussed consisting of modeling the musculoskeletal system with Hill-type phenomenological muscle models and computing the metabolical expenditure adopting expressions recently proposed in the literature. As an example a musculoskeletal model of the lower limb in the sagittal plane consisting of thigh, shank and foot with three degrees of freedom and actuated by eight muscles is considered. This model is used to estimate metabolical costs for known normal gait kinematical data obtained in a gait analysis laboratory.

Development of a Lower Limb Orthosis to Form Neuromuscular Patterning

2014 ◽  
Author(s):  
Karla A. Camarillo–Gómez ◽  
Gerardo I. Pérez-Soto ◽  
Luis A. Torres-Rico
Keyword(s):  
Quality Of Life ◽  
Control System ◽  
Lower Limb ◽  
Gait Cycle ◽  
Lower Cost ◽  
Sagittal Plane ◽  
Lower Limbs ◽  
Human Gait

In this paper, a lower limb orthosis is proposed to form the human gait neuromuscular patterns in patients with myelomeningocele. The orthosis has two lower limbs of 2–DOF each which reduces the motion of the hip and knee to the sagittal plane. The orthosis are assembled in a back support which also supports the patients weight. The control system for the orthosis allows to reproduce in a repetitive, controlled and autonomous way the human gait cycle at different velocities according to the patient requirements; so that, the neuromuscular patterning can be supervised by a therapist. The development of these orthosis seeks to improve the quality of life of those infants with myelomenigocele and to introduce a lower cost Mexican technology with Mexican anthropometric dimensions.

scholarly journals A Review of Existing Transtibial Bionic Prosthesis: Mechanical Design, Actuators and Power Transmission

2022 ◽  
Vol 1 (2) ◽  
pp. 65-72
Author(s):  
Ade Reza Ismawan ◽  
Rifky Ismail ◽  
Tony Prahasto ◽  
Mochammad Ariyanto ◽  
Budi Setiyana
Keyword(s):  
Gait Cycle ◽  
Power Transmission ◽  
Mechanical Design ◽  
Body Part ◽  
Gait Pattern ◽  
Metabolic Energy ◽  
Human Gait ◽  
Transtibial Prosthesis ◽  
Selection Of

Transtibial and transfemoral amputations are the most common amputations in the world, loss of lower extremity result in impaired function extremities and also body balance. A prosthesis is a medical device designed to replace a specific body part to restore function to a body part lost due to an accident or disease. Most doctors strongly recommend the use of a prosthesis so that patients can return to normal activities after undergoing an amputation. Besides functioning to support beauty, the use of prostheses is also to restore the quality of life of prosthetic users, the issue of metabolic energy consumption when walking is also very important in designing transtibial bionic prosthesis because it involves the comfort of the user transtibial prosthesis. Most of the existing transtibial prosthesis products in Indonesia are conventional passive transtibial foot products, and passive prosthesis users show a limp or asymmetrical gait pattern so that conventional passive prosthesis users experience discomfort when walking in the form of pain in the amputated leg and normal foot, which can cause secondary musculoskeletal injuries such as joint disorders. Passive prostheses cannot generate propulsive force during push-off phase (terminal stance and preswing) of the human gait cycle. The use of passive prostheses can also consume 20-30% more metabolic energy while walking so that it can cause fatigue for the user. Transtibial bionic prosthesis research is growing, transtibial bionic prosthesis can overcome the weakness of passive prosthesis because it can produce push-off during gait cycle and several researchers have shown that bionic prostheses are capable of mimicking the human gait, as well as improve the  performance in a more natural gait and normal walking. This study aims to study the existing transtibial bionic prosthesis by comparing between 6 existing designs of powered ankle or transtibial bionic prosthesis that have been published in several publications. The discussion focuses on the design and mechanical systems, actuators related to the selection of motors and drive mechanisms as well as power transmission from actuators to moving components.

scholarly journals Effect of Common Pavements on Interjoint Coordination of Walking with and without Robotic Exoskeleton

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Jinlei Wang ◽  
Jing Qiu ◽  
Lei Hou ◽  
Xiaojuan Zheng ◽  
Suihuai Yu
Keyword(s):  
Gait Cycle ◽  
Sagittal Plane ◽  
Motor Recovery ◽  
Human Gait ◽  
Interjoint Coordination ◽  
Design And Optimization ◽  
Robotic Exoskeleton ◽  
The Common ◽  
Coordination Patterns ◽  
Healthy Participants

Background. The analysis and comprehension of the coordination control of a human gait on common grounds benefit the development of robotic exoskeleton for motor recovery. Objective. This study investigated whether the common grounds effect the interjoint coordination of healthy participants with/without exoskeletons in walking. Methods. The knee-ankle coordination and hip-knee coordination of 8 healthy participants in a sagittal plane were measured on five kinds of pavements (tiled, carpet, wooden, concrete, and pebbled) with/without exoskeletons, using the continuous relative phase (CRP). The root mean square of CRP (CRPRMS) over each phase of the gait cycle is used to analyze the magnitude of dephasing between joints, and the standard deviation of CRP (CRPSD) in the full gait cycle is used to assess the variability of coordination patterns between joints. Results. The CRPHip-Knee/RMS of the carpet pavement with exoskeleton is different from that of other pavements (except the tiled pavement) in the midstance phase. The CRPHip-Knee/RMS on the pebble pavement without exoskeleton is less than that on the other pavements in all phases. The CRPHip-Knee/SD of the pebble pavement without exoskeleton is smaller than that of other pavements. The CRPKnee-Ankle/SD with/without exoskeleton is similar across all pavements. Conclusion. The compressive capacity of the pavement and the unevenness of the pavement are important factors that influence interjoint coordination, which can be used as key control elements of gait to adapt different pavements for robotic exoskeleton. Novelty. We provide a basis of parameter change of kinematics on different common grounds for the design and optimization of robotic exoskeleton for motor recovery.

scholarly journals Evaluation of gait cycle time variability in patients with knee osteoarthritis using a triaxial accelerometer

2021 ◽  
Author(s):  
Takeshi Akimoto ◽  
Kenji Kawamura ◽  
Takaaki Wada ◽  
Naomichi Ishihara ◽  
Akane Yokota ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Knee Osteoarthritis ◽  
Gait Cycle ◽  
Elderly Women ◽  
Knee Extension ◽  
Walk Test ◽  
Contributing Factors ◽  
Healthy Elderly ◽  
Unstable Gait

Knee osteoarthritis can alter gait variability. However, few studies have compared the temporal factors of the gait cycle between patients with knee osteoarthritis and healthy subjects. Furthermore, no studies have investigated the relationship between gait variability and potential contributing factors (knee joint functions such as muscle strength) in knee osteoarthritis. The first objective of this study was to compare gait cycle variability between female patients with knee osteoarthritis and healthy elderly women to determine gait characteristics in patients with knee osteoarthritis. The second objective was to examine whether gait cycle variability in knee osteoarthritis is associated with potential contributing factors. Twenty-four female patients diagnosed with knee osteoarthritis and 12 healthy elderly women participated. Gait cycle variability (coefficient of variation of gait cycle time), knee extension range of motion, knee extension strength, 5-meter walk test, Timed Up & Go Test, and Western Ontario and McMaster Universities Osteoarthritis Index were measured. All assessment results were compared between the knee osteoarthritis and healthy groups. Gait cycle variability was significantly higher in the knee osteoarthritis group (3.2%) compared to the healthy group (2.1%). A significant positive correlation was found between the gait cycle variability and 5-meter walk test (r=0.46) and Western Ontario and McMaster Universities Osteoarthritis Index (r=0.43). The gait of patients with knee osteoarthritis may be more unstable than that of healthy individuals. In addition, unstable gait may be associated with gait speed and quality of life. Therefore, we believe that rehabilitation to improve unstable gait can enhance the quality of life of patients with knee osteoarthritis.

The concept of motivation for effective credit risk management

2020 ◽  
Vol 26 (11) ◽  
pp. 2567-2593
Author(s):  
M.V. Pomazanov
Keyword(s):  
Risk Management ◽  
Economic Modeling ◽  
Type I ◽  
Credit Risk Management ◽  
Curve Modeling ◽  
Business Functions ◽  
The Common ◽  
Lending Decisions ◽  
The One

Subject. The study addresses the improvement of risk management efficiency and the quality of lending decisions made by banks. Objectives. The aim is to present the bank management with a fair algorithm for risk management motivation on the one hand, and the credit management (business) on the other hand. Within the framework of the common goal to maximize risk-adjusted income from loans, this algorithm will provide guidelines for ‘risk management’ and ‘business’ functions on how to improve individual and overall efficiency. Methods. The study employs the discriminant analysis, type I and II errors, Lorentz curve modeling, statistical analysis, economic modeling. Results. The paper offers a mechanism for assessing the quality of risk management decisions as opposed to (or in support of) decisions of the lending business when approving transactions. The mechanism rests on the approach of stating type I and II errors and the corresponding classical metric of the Gini coefficient. On the ‘business’ side, the mechanism monitors the improvement or deterioration of the indicator of changes in losses in comparison with the market average. Conclusions. The study substantiates the stimulating ‘rules of the game’ between the ‘business’ and ‘risk management’ to improve the efficiency of the entire business, to optimize interactions within the framework of internal competition. It presents mathematical tools to calculate corresponding indicators of the efficiency of internally competing entities.

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