Powered Ankle-Foot Prostheses: A Survey on Sensing Systems and Control Strategies

2019 ◽  
Author(s):  
Erik Chumacero-Polanco ◽  
James Yang
Keyword(s):  
Control Strategies ◽  
Level Control ◽  
Low Level ◽  
Kinetic Information ◽  
Sensing Systems ◽  
Systems And Control ◽  
Finite State ◽  
High Level ◽  
And Control

Abstract People who have suffered a transtibial amputation show diminished ambulation and impaired quality of life. Powered ankle foot prostheses (AFP) are used to recover some mobility of transtibial amputees (TTAs). Powered AFP is an emerging technology that has great potential to improve the quality of life of TTAs with important avenues for research and development in different fields. This paper presents a survey on sensing systems and control strategies applied to powered AFPs. Sensing kinematic and kinetic information in powered AFPs is critical for control. Ankle angle position is commonly obtained via potentiometers and encoders directly installed on the joint, velocities can be estimated using numerical differentiators, and accelerations are normally obtained via inertial measurement units (IMUs). On the other hand, kinetic information is usually obtained via strain gauges and torque sensors. On the other hand, control strategies are classified as high- and low-level control. The high-level control sets the torque or position references based on pattern generators, user’s intent of motion recognition, or finite-state machine. The low-level control usually consists of linear controllers that drive the ankle’s joint position, velocity, or torque to follow an imposed reference signal. The most widely used control strategy is the one based on finite-state machines for the high-level control combined with a proportional-derivative torque control for low-level. Most designs have been experimentally assessed with acceptable results in terms of walking speed. However, some drawbacks related to powered AFP’s weight and autonomy remain to be overcome. Future research should be focused on reducing powered AFP size and weight, increasing energy efficiency, and improving both the high- and the low-level controllers in terms of efficiency and performance.

Implementation of robotic ankle–foot orthosis with an impedance-based assist-as-needed control strategy

2021 ◽  
pp. 1-40
Author(s):  
Bing Chen ◽  
Bin Zi ◽  
Bin Zhou ◽  
Zhengyu Wang
Keyword(s):  
Level Control ◽  
Ankle Foot Orthosis ◽  
Low Level ◽  
Ankle Impedance ◽  
Torque Generation ◽  
Ankle Rehabilitation ◽  
Finite State ◽  
Proportional Derivative Controller ◽  
High Level ◽  
Foot Orthosis

Abstract In this paper, a robotic ankle–foot orthosis (AFO) is developed for individuals with a paretic ankle, and an impedance-based assist-as-needed controller is designed for the robotic AFO to provide adaptive assistance. First, a description of the robotic AFO hardware design is presented. Next, the design of the finite state machine is introduced, followed by an introduction to the modelling of the robotic AFO. Additionally, the control of the robotic AFO is presented. An impedance-based high-level controller that is composed of an ankle impedance based torque generation controller and an impedance controller is designed for the high-level control. A compensated low-level controller that is composed of a braking controller and a proportional-derivative controller with a compensation part is designed for the low-level control. Finally, a pilot study is conducted, and the experimental results demonstrate that with the proposed control algorithm, the robotic AFO has the potential for ankle rehabilitation by providing adaptive assistance. In the assisted condition with a high level of assistance, reductions of 8% and 20.1% of the root mean square of the tibialis anterior and lateral soleus activities are observed, respectively.

scholarly journals Development of a Low-Level Control System for the ROV Visor3

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Santiago Rúa ◽  
Rafael E. Vásquez
Keyword(s):  
Mathematical Model ◽  
Control System ◽  
Nonlinear Observer ◽  
Navigation Systems ◽  
Level Control ◽  
Remotely Operated Vehicle ◽  
Low Level ◽  
Level Control System ◽  
High Level ◽  
And Control

This paper addresses the development of the simulation of the low-level control system for the underwater remotely operated vehicle Visor3. The 6-DOF mathematical model of Visor3 is presented using two coordinated systems: Earth-fixed and body-fixed frames. The navigation, guidance, and control (NGC) structure is divided into three layers: the high level or the mission planner; the mid-level or the path planner; and the low level formed by the navigation and control systems. The nonlinear model-based observer is developed using the extended Kalman filter (EKF) which uses the linearization of the model to estimate the current state. The behavior of the observer is verified through simulations using Simulink®. An experiment was conducted with a trajectory that describes changes in the x and y and yaw components. To accomplish this task, two algorithms are compared: a multiloop PID and PID with gravity compensation. These controllers and the nonlinear observer are tested using the 6-DOF mathematical model of Visor3. The control and navigation systems are a fundamental part of the low-level control system that will allow Visor3’s operators to take advantage of more advanced vehicle’s capabilities during inspection tasks of port facilities, hydroelectric dams, and oceanographic research.

Morphological traits of the development of the skin and wool cover in sheep of Prikatunsky meat and wool type

2021 ◽  
pp. 60-68
Author(s):  
I. I. Dmitrik ◽  
G. V. Zavgorodnyaya ◽  
M. I. Pavlova ◽  
N. A. Podkorytov
Keyword(s):  
Physical Properties ◽  
Morphological Traits ◽  
Age Groups ◽  
Body Side ◽  
Low Level ◽  
Research Material ◽  
High Level ◽  
Significant Factors

A large number of works are devoted to the development of the skin and hair cover of sheep, depending on their breed affiliation, age, feeding conditions and housing. The authors point out that along with other conditions the quality of wool and wool clip is greatly influenced by the conditions of the feeding of animals. A high level of feeding increases the wool clip and improves the quality of the wool and vice versa a low level reduces, causes thinning and worsens other physical properties of the wool. As is known, one of the significant factors that determine the increase in wool clip is the size of the animal and, consequently, the total area of the skin. The purpose of the research was to investigate the morphological traits of the development of the skin and wool cover in sheep of Prikatunsky meat and wool type. The research material was wool samples from four topographic areas of the animal’s body (side/thigh/back/belly) and skin (side) of different sex and age groups, selected from the animals of the studied groups. In the course of research, the quality of wool and indicators of the histostructure of the skin of Prikatunsky meat and wool type of sheep have been investigated. In terms of thick-haired of wool, replacement rams and gimbers of Prikatunsky meat and wool type of sheep were superior by 4,82 pcs. per mm² or 19,0 % and 4,41 pcs. per mm² or 15,8 % of adult animals, respectively. Balance secondary follicles/primary follicles in young animals were higher by 10,3 and 17,3 % compared to breeding rams and ewes. The wool of the replacement young animals was thinner by 7,28 and 4,78 microns and they were more thick-haired. The obtained data will be used in the mating campaign when mating program rams in order to improve the sheep of Prikatunsky meat and wool type.

scholarly journals A Comparative Study to Assess the Quality of Life and Stress among Orphan and Non-orphan Children in Selected Areas of Bagalkot

2020 ◽  
Vol 11 (04) ◽  
pp. 19-25
Author(s):  
Santosh B Sajjan ◽  
Keyword(s):  
Quality Of Life ◽  
High Stress ◽  
Poor Quality ◽  
Demographic Variables ◽  
Self Report ◽  
Stress Scale ◽  
Low Level ◽  
High Level ◽  
Moderate Stress

Introduction: The word orphan comes from the Greek word ‘Orfanos’ and refers to a child permanently bereaved of or abandoned by his or her parents. Methods: A non-experimental descriptive comparative design has been adopted for the present study. The sample of the present study comprises orphan children residing in an orphanage and non-orphan children residing in selected areas of Bagalkot. The sample comprised 30 orphans and 30 non-orphans aged between 10 and 16 years. The data were collected by using self-report, structured closed-ended questionnaires for socio-demographic variables of children, self-administered WHO Quality of life BREF scale, and PSS stress scale. The data obtained were analysed with the help of descriptive and inferential statistics. Result: Findings related to the comparison between the level of stress among the orphan and non-orphan children revealed that majority of orphan children (76.66%) had about moderate stress, 23.33% of the orphan children had high stress, and none of the children had a low level of stress, whereas among non-orphan children, majority (90%) had moderate stress, 10% had low level stress, and none of them had high level stress. The findings related to the comparison of levels of quality of life among the orphan and non-orphan children reveal that a high percentage of orphan children (66.66%) had a moderate quality of life and some of them (33.33%) had a poor quality of life, whereas a high number of non-orphan children (66.66%) had a very good quality of life and some (33.33%) had a good quality of life. No significant association was found between the quality of life and stress scores with the socio-demographic variables of orphan and non-orphan children. Conclusion: The study concluded that orphan children need to improve their quality of life and decrease their level of stress.

Development of a soft cable-driven hand exoskeleton for assisted rehabilitation training

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Dawen Xu ◽  
Qingcong Wu ◽  
Yanghui Zhu
Keyword(s):  
Muscle Activation ◽  
Control Strategies ◽  
Motor Dysfunction ◽  
Force Transmission ◽  
Content Type ◽  
Rehabilitation Training ◽  
Local Structures ◽  
Hand Exoskeleton ◽  
And Control

Purpose Hand motor dysfunction has seriously reduced people’s quality of life. The purpose of this paper is to solve this problem; different soft exoskeleton robots have been developed because of their good application prospects in assistance. In this paper, a new soft hand exoskeleton is designed to help people conduct rehabilitation training. Design/methodology/approach The proposed soft exoskeleton is an under-actuated cable-driven mechanism, which optimizes the force transmission path and many local structures. Specifically, the path of force transmission is optimized and cables are wound around cam-shaped spools to prevent cables lose during fingers movement. Besides, a pre-tightening system is presented to adjust the preload force of the cable-tube. Moreover, a passive brake mechanism is proposed to prevent the cables from falling off the spools when the remote side is relaxed. Findings Finally, three control strategies are proposed to assist in rehabilitation training. Results show that the average correlation coefficient of trajectory tracking is 90.99% and this exoskeleton could provide steady clamping force up to 35 N, which could meet the demands of activities in daily living. Surface electromyography (sEMG)-based intention recognition method is presented to complete assistance and experiments are conducted to prove the effectiveness of the assisted grasping method by monitoring muscle activation, finger angle and interactive force. Research limitations/implications However, the system should be further optimized in terms of hardware and control to reduce delays. In addition, more clinical trials should be conducted to evaluate the effect of the proposed rehabilitation strategies. Social implications May improve the ability of hemiplegic patients to live independently. Originality/value A novel under-actuated soft hand exoskeleton structure is proposed, and an sEMG-based auxiliary grasping control strategy is presented to help hemiplegic patients conduct rehabilitation training.

scholarly journals Management in the paediatric wards facing novel coronavirus infection: a rapid review of guidelines and consensuses

BMJ Open ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. e039897
Author(s):  
Wen-Yi Luo ◽  
Ji-Wen Sun ◽  
Wen-Lan Zhang ◽  
Qian Li ◽  
Ping Ni ◽  
...  
Keyword(s):  
Control Strategies ◽  
Stakeholder Involvement ◽  
Rapid Review ◽  
Cochrane Library ◽  
China National Knowledge Infrastructure ◽  
Agree Ii ◽  
Relevant Evidence ◽  
And Control ◽  
Agree Ii Tool

ObjectivesRelevant guidelines and consensuses for COVID-19 contain recommendations aimed at optimising the management in paediatric wards. The goal of this study was to determine the quality of those recommendations and provide suggestions to hospital managers for the adjustment of existing hospital prevention and control strategies, and also to offer recommendations for further research.DesignA rapid review of the guidelines and consensuses for the management in paediatric wards facing COVID-19.MethodsPubMed, EMBASE, the Cochrane Library, UpToDate, China National Knowledge Infrastructure, the Wanfang database and relevant websites such as medlive.cn, dxy.cn, the National Health and Health Commission and the China Center for Disease Control and Prevention were systematically searched through late May 2020. The Appraisal of Guidelines for Research and Evaluation II (AGREE II) tool was then used to assess the quality of the selected articles and summarise the relevant evidence concerning management in paediatric wards.ResultsA total of 35 articles were included, composed of 3 consensus guidelines, 25 expert consensuses and 7 expert opinions. Of the 35 papers, 24 were from China, 2 from the USA, 1 from Spain, 1 from Brazil, 1 from Saudi Arabia and 6 from multinational cooperative studies. Scores for the six domains of the AGREE II tool (scope and purpose, stakeholder involvement, rigour of development, clarity of presentation, applicability and editorial independence) were 98.57%, 53.57%, 17.92%, 69.62%, 26.96% and 50.35%, respectively. Recommendations for nosocomial infection and control, human resource management as well as management of paediatric patients and their families were summarised.ConclusionsDue to the outbreak of COVID-19, the quality of rapid guidelines and consensuses for the management in paediatric wards affected by COVID-19 is unsatisfactory. In the future, it will be necessary to develop more high-quality guidelines or consensuses for the management in paediatric wards to deal with nosocomial outbreaks in order to fully prepare for emergency medical and health problems.

Comparison of quality of facial scars after single low-level laser therapy and combined low-level with high-level (PDL 595 nm) laser therapy

2015 ◽  
Vol 28 (4) ◽  
pp. 201-209 ◽  
Author(s):  
Jana Vranova ◽  
Eva Remlova ◽  
Helena Jelinkova ◽  
Jozef Rosina ◽  
Tatjana Dostalova
Keyword(s):  
Laser Therapy ◽  
Low Level Laser Therapy ◽  
Low Level ◽  
Low Level Laser ◽  
Level Laser ◽  
High Level

scholarly journals PENERAPAN DATA MINING DALAM MENGELOMPOKAN PRODUKSI JAGUNG MENURUT PROVINSI MENGGUNAKAN ALGORITMA K-MEANS

2019 ◽  
Vol 3 (1) ◽  
Author(s):  
Nanda Erlangga ◽  
Solikhun Solikhun ◽  
Irawan Irawan
Keyword(s):  
Data Mining ◽  
Clustering Algorithm ◽  
Rapid Development ◽  
Domestic Market ◽  
Corn Production ◽  
Low Level ◽  
High Level ◽  
Level Cluster ◽  
Central Statistics

Corn needs are currently experiencing a fairly rapid development can be seen in terms of the domestic market, here researchers want to increase the productivity and quality of corn production. The data that will be used is the data from the Central Statistics Agency. The method in this study is the K-means clustering algorithm and the application used is Rapidminer which will be grouped into 2 clustering, namely high and low. The results of this study are 2 high level cluster provinces, 32 low level cluster provincesKeywords: Corn, Data mining, K-means Clustering c

scholarly journals ANALISIS BUKU AJAR MARUGOTO: BAHASA DAN KEBUDAYAAN JEPANG A1 DITINJAU DARI RANAH KOGNITIF TAKSONOMI BLOOM

2018 ◽  
Vol 3 (1) ◽  
pp. 24
Author(s):  
Rakhmania Wulandari ◽  
Febi Ariani Saragih
Keyword(s):  
Bloom's Taxonomy ◽  
Data Sources ◽  
Learning Needs ◽  
Language And Culture ◽  
Low Level ◽  
Descriptive Research ◽  
Bloom’S Taxonomy ◽  
Qualitative Descriptive ◽  
High Level

Penelitian ini bertujuan untuk mengetahui kualitas isi buku ajar Marugoto: Bahasa dan Kebudayaan Jepang A1 ditinjau dari ranah kognitif taksonomi Bloom.  Kualitas buku ajar menjadi pertimbangan pengajar dalam menentukan buku ajar yang baik untuk digunakan. Menelaah kualitas buku ajar dapat dilakukan dengan menggunakan teori belajar taksonomi Bloom. Taksonomi Bloom adalah pengelompokan belajar berdasarkan tingkatan belajar. Yaitu belajar tingkat rendah yang terdiri dari kualifikasi C1 (mengingat), C2 (memahami), dan C3 (mengaplikasikan), serta belajar tingkat tinggi yang terdiri dari kualifikasi  C4 (menganalisis), C5 (mengevaluasi), dan C6 (mencipta).Penelitian ini merupakan penelitian deskriptif kualitatif. Sumber data utama adalah buku ajar Marugoto rikai dan katsudou. Analisis dilakukan dengan menganalisis bahan ajar menggunakan kualifikasi kognitif pada taksonomi Bloom. Hasil Analisis menunjukkan bahwa buku Marugoto A1 mencapai hasil yang sangat baik pada kualifikasi C1, C2, C3, C4; hasil analisis baik pada C5, dan  hasil analisis sangat kurang pada C6. Materi yang disajikan mewakili kata kerja operasioanal dalam memenuhi kebutuhan belajar tingkat rendah dengan sangat baik, namun hanya cukup mewakili kata kerja operasional dalam memenuhi kebutuhan belajar tingkat tinggi.   This research is aimed to find out the quality of Marugoto's textbook content: Japanese Language and Culture A1 from the cognitive aspects of Bloom's taxonomy. The quality of textbooks becomes the teacher's consideration in determining which textbooks are best used. Reviewing the quality of textbooks can be done using Bloom's theory of taxonomic learning. Bloom's Taxonomy is a learning grouping based on the level of learning. That is a low level study consisting of qualifications C1 (remembering), C2 (understanding), and C3 (applying), as well as a high-level learning consisting of C4 qualifying (analyzing), C5 (evaluating), and C6 (creating). is a qualitative descriptive research. The main data sources are Marugoto rikai and katsudou textbooks. The analysis was done by analyzing the teaching materials using cognitive qualifications on Bloom's taxonomy. The analysis shows that Marugoto: Language and Culture of Japan A1 achieved excellent results on qualification C1, C2, C3, C4, good analytical results on C5, and the result of analysis is very less on C6. The material presented represents operational verbs in meeting low-level learning needs very well, but only enough to represent operational verbs in meeting high-level learning needs.

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