scholarly journals A myoelectric prosthetic hand with muscle synergy–based motion determination and impedance model–based biomimetic control

2019 ◽  
Vol 4 (31) ◽  
pp. eaaw6339 ◽  
Author(s):  
Akira Furui ◽  
Shintaro Eto ◽  
Kosuke Nakagaki ◽  
Kyohei Shimada ◽  
Go Nakamura ◽  
...  
Keyword(s):  
Upper Limb ◽  
Impedance Control ◽  
Three Dimensional ◽  
Human Motion ◽  
Muscle Synergy ◽  
Prosthetic Hand ◽  
Control Mechanisms ◽  
Finger Movements ◽  
Prosthetic Hands

Prosthetic hands are prescribed to patients who have suffered an amputation of the upper limb due to an accident or a disease. This is done to allow patients to regain functionality of their lost hands. Myoelectric prosthetic hands were found to have the possibility of implementing intuitive controls based on operator’s electromyogram (EMG) signals. These controls have been extensively studied and developed. In recent years, development costs and maintainability of prosthetic hands have been improved through three-dimensional (3D) printing technology. However, no previous studies have realized the advantages of EMG-based classification of multiple finger movements in conjunction with the introduction of advanced control mechanisms based on human motion. This paper proposes a 3D-printed myoelectric prosthetic hand and an accompanying control system. The muscle synergy–based motion-determination method and biomimetic impedance control are introduced in the proposed system, enabling the classification of unlearned combined motions and smooth and intuitive finger movements of the prosthetic hand. We evaluate the proposed system through operational experiments performed on six healthy participants and an upper-limb amputee participant. The experimental results demonstrate that our prosthetic hand system can successfully classify both learned single motions and unlearned combined motions from EMG signals with a high degree of accuracy. Furthermore, applications to real-world uses of prosthetic hands are demonstrated through control tasks conducted by the amputee participant.

A custom, functional and lifelike passive prosthetic hand for infants and small toddlers: Clinical note

2020 ◽  
Vol 44 (3) ◽  
pp. 180-184
Author(s):  
Arezoo Eshraghi ◽  
Jaeeun Yoo ◽  
James Klein ◽  
Ian Mckenzie ◽  
Gabrielle Sebaldt ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Upper Limb ◽  
Low Cost ◽  
Prosthetic Hand ◽  
Functional Requirements ◽  
Infants And Toddlers ◽  
Clinical Note ◽  
Alloy Wire ◽  
Prosthetic Hands ◽  
Limb Deficiencies

Background and Aim: For infants and small toddlers with congenital upper limb deficiencies, terminal devices mainly provide either cosmesis or functionality. We report a clinical note about fitting a child with a low-cost passive hand targeting both functionality and cosmesis. Technique: An elastomeric, alloy-wire-reinforced hand was fabricated using additive manufacturing to allow independent positioning of the digits. A clinical pilot in-home evaluation was conducted on a child with upper limb loss. Discussion: The fabricated hand met the functional requirements but required a cover for cosmesis due to a poor surface finish associated with the fabrication technique. The participant child was comfortable using the prosthesis for various tasks. The parents were satisfied with the hand’s function and cosmesis when covered with a cosmetic glove. This work demonstrated a new design and process that may in the future improve the utilization of prosthetic hands to promote early prosthesis use and a child’s development. Clinical relevance Early prosthesis use is important for infants and toddlers. Additive manufacturing may enable the fabrication of custom passive prosthetic hands that provide both cosmesis and functionality.

Design and experiment of a modular multisensory hand for prosthetic applications

2017 ◽  
Vol 44 (1) ◽  
pp. 104-113 ◽  
Author(s):  
Bo Zeng ◽  
Shaowei Fan ◽  
Li Jiang ◽  
Hong Liu
Keyword(s):  
Contact Force ◽  
Upper Limb ◽  
Impedance Control ◽  
Transmission Mechanism ◽  
Human Hand ◽  
Prosthetic Hand ◽  
Control Performance ◽  
Content Type ◽  
Multiple Sensors ◽  
Modular Unit

Purpose This paper aims to present the design and experiment of a modular multisensory prosthetic hand for applications. Design and experiment of a modular multisensory hand for prosthetic applications. Design/methodology/approach This paper reveals more details focusing on the appearance, mechanism design, electrical design and control of the prosthetic hand considering anthropomorphism, dexterity, sensing and controllability. The finger is internally integrated with the actuator, the transmission mechanism, the sensors and the controller as a modular unit. Integrated with multiple sensors, the prosthetic hand can not only perceive the position, the contact force and the temperature of the environment like a human hand but also provide the foundation for the practical control. Findings The experiments show that the prosthetic hand can accurately control the contact force to achieve stable grasps based on the sensors feedback and a simple and effective force-tracking impedance control algorithm. In addition, the experiments based on the cosmesis validate not only the cosmesis functionality but also the control performance for a prosthesis–cosmesis system. Practical implications Because of the small size, low weight, high integration, modularity and controllability, the prosthetic hand is easily applied to upper-limb amputees. Meanwhile, the finger as a modular unit is easy to be fixed, maintained and applied to a partial upper-limb amputee. Originality/value Each modular finger of the prosthetic hand integrated with the actuator, the transmission mechanism, the sensors and the controller as a whole can independently control the position and the force. The cosmetic glove design can provide pretty appearance without compromising the control performance.

scholarly journals The i-LIMB Hand and the DMC Plus Hand Compared: A Case Report

2010 ◽  
Vol 34 (2) ◽  
pp. 216-220 ◽  
Author(s):  
Olga Van Der Niet Otr ◽  
Heleen A. Reinders-Messelink ◽  
Raoul M. Bongers ◽  
Hanneke Bouwsema ◽  
Corry K. Van Der Sluis
Keyword(s):  
Case Report ◽  
Upper Limb ◽  
Functional Outcomes ◽  
Test Procedure ◽  
International Classification ◽  
Dynamic Mode ◽  
Prosthetic Hand ◽  
Patient’S Satisfaction ◽  
New Device

The i-LIMB hand is a novel upper limb myoelectric prosthetic hand with several joints in the fingers and thumb. This study aimed to determine whether this new device had more functionality than a more conventional myoelectric prosthetic hand with only a single joint between the thumb and two fingers. Therefore, a 45-year-old man with a wrist disarticulation used the i-LIMB hand and the widely used Dynamic Mode Control hand (DMC plus hand) in a test procedure that covered all functional levels of the International Classification of Function (ICF). Functional outcomes of the i-LIMB seemed to be lower than or equal to the DMC plus hand. The patient's satisfaction tended to be in favor of the i-LIMB. Compared to the DMC plus hand, the i-LIMB was more reliable when holding objects but had a lack of power and was less robust. We concluded that the i-LIMB hand has limited additional functionality compared to the DMC plus hand.

scholarly journals Enhancing Prediction of Prosthetic Fingers Movement Based on sEMG using Mixtures of Features and Random Forest

2019 ◽  
Vol 8 (4) ◽  
pp. 289-294
Keyword(s):  
Random Forest ◽  
Frequency Domain ◽  
Extraction Methods ◽  
Surface Emg ◽  
Majority Voting ◽  
Statistical Features ◽  
Finger Movements ◽  
Prosthetic Hands ◽  
Prosthetic Finger

As the recent development of the prosthetic control systems, it is necessary to develop the sub-components such as myoelectric control system. This sub-system is used to acquire electromyogram (EMG) signals from a person's muscles and convert it to movements to control prosthetic hands or fingers. Recently, researchers started focusing on providing feature extraction methods for both time domain and frequency domain for predicting either hand or finger movements. This paper proposes a new mixed feature set for both time and frequency domain for the classification of surface EMG (sEMG) into ten classes for controlling prosthetic finger movements. The features are based on enhanced statistical features extracted directly from a non-overlapped window with a predefined length which was selected carefully from the sEMG directly. Ten classes of individual and combined finger movements are to be recognized by using two sEMG channels from two electrodes are fixed on the human forearm to employ effective knowledge discovery and pattern recognition algorithms to enhance the recognition and classification accuracy. and the other features are statistical features extracted from Instantaneous frequency of the signal to utilize a suitable classifier helps detecting and recognizing the pattern from sEMG signals of different classes of the fingers movements either combined or single movement to enhance the classifier performances and to find the whole class of all extracted window ,a majority voting technique was applied.The method used the random forest as a classifier to build the classifier model which achieved an accuracy of 93.75% and sensitivity of 93.73% and specificity of 99.31%

Design of a Novel Locking Ratcheting Mechanism for a Body-Powered Underactuated Hand

2020 ◽  
Vol 14 (1) ◽  
Author(s):  
Hun Chan Lee ◽  
Raymond Cipra
Keyword(s):  
Three Dimensional ◽  
Prosthetic Hand ◽  
3D Printer ◽  
Force Analysis ◽  
Joint Angles ◽  
Actual System ◽  
Prosthetic Hands ◽  
Awkward Position ◽  
3D Printers ◽  
Different Shapes

Abstract As affordable and efficient three-dimensional (3D) printers became widely available, researchers are focusing on developing prosthetic hands that are reasonably priced and effective at the same time. By allowing anyone with a 3D printer to build a body-powered prosthetic hand, many people could build their own prosthetic hand. However, one of the major problems with the current designs is the users must bend and hold their wrist in an awkward position to grasp an object. The primary goal of this work is to present the design process and analysis of a body-powered underactuated prosthetic hand with a novel ratcheting mechanism that locks the finger automatically at a desired position. To estimate how a compliant finger behaves on the actual system with the ratcheting mechanism, the preshaping analysis and the preshaping experiment were conducted. From the experiment, the presence of elastic hysteresis was observed. Additionally, the contact force analysis was performed to see the effects of joint angles and applied tension force. To test how well the hand can grasp, a cup with various weights was lifted and various objects with different shapes were grasped to prove how well the compliant finger can adapt to the shape of the objects. Based on the experiment, the hand had a higher success rate of grasping objects that are lightweight (less than 500 g) and cylindrical or circular shaped.

Phonetic iconicity in the evaluative morphology of a sample of Indo-European, Niger-Congo and Austronesian languages

2010 ◽  
Vol 3 (2) ◽  
pp. 156-180 ◽  
Author(s):  
Renáta Gregová ◽  
Lívia Körtvélyessy ◽  
Július Zimmermann
Keyword(s):  
Three Dimensional ◽  
Sound Symbolism ◽  
Three Dimensional Model ◽  
Austronesian Languages ◽  
Place Of Articulation ◽  
European Languages ◽  
Phonetic Symbolism ◽  
The Individual ◽  
Core Vocabulary

Universals Archive (Universal #1926) indicates a universal tendency for sound symbolism in reference to the expression of diminutives and augmentatives. The research ( Štekauer et al. 2009 ) carried out on European languages has not proved the tendency at all. Therefore, our research was extended to cover three language families – Indo-European, Niger-Congo and Austronesian. A three-step analysis examining different aspects of phonetic symbolism was carried out on a core vocabulary of 35 lexical items. A research sample was selected out of 60 languages. The evaluative markers were analyzed according to both phonetic classification of vowels and consonants and Ultan's and Niewenhuis' conclusions on the dominance of palatal and post-alveolar consonants in diminutive markers. Finally, the data obtained in our sample languages was evaluated by means of a three-dimensional model illustrating the place of articulation of the individual segments.

scholarly journals How Can I Grab That?

i-com ◽  
2020 ◽  
Vol 19 (2) ◽  
pp. 67-85
Author(s):  
Matthias Weise ◽  
Raphael Zender ◽  
Ulrike Lucke
Keyword(s):  
Virtual Reality ◽  
User Experience ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Advantages And Disadvantages ◽  
Multiple Dimensions ◽  
Application Developers ◽  
Three Dimensional Space

AbstractThe selection and manipulation of objects in Virtual Reality face application developers with a substantial challenge as they need to ensure a seamless interaction in three-dimensional space. Assessing the advantages and disadvantages of selection and manipulation techniques in specific scenarios and regarding usability and user experience is a mandatory task to find suitable forms of interaction. In this article, we take a look at the most common issues arising in the interaction with objects in VR. We present a taxonomy allowing the classification of techniques regarding multiple dimensions. The issues are then associated with these dimensions. Furthermore, we analyze the results of a study comparing multiple selection techniques and present a tool allowing developers of VR applications to search for appropriate selection and manipulation techniques and to get scenario dependent suggestions based on the data of the executed study.

Research on cargo-loading optimization based on genetic and fuzzy integration

2021 ◽  
Vol 40 (4) ◽  
pp. 8493-8500
Author(s):  
Yanwei Du ◽  
Feng Chen ◽  
Xiaoyi Fan ◽  
Lei Zhang ◽  
Henggang Liang
Keyword(s):  
Genetic Algorithm ◽  
Mathematical Model ◽  
Three Dimensional ◽  
Distribution Center ◽  
Long Time ◽  
Low Efficiency ◽  
Decision Making Model ◽  
The Mathematical Model ◽  
Loading Scheme

With the increase of the number of loaded goods, the number of optional loading schemes will increase exponentially. It is a long time and low efficiency to determine the loading scheme with experience. Genetic algorithm is a search heuristic algorithm used to solve optimization in the field of computer science artificial intelligence. Genetic algorithm can effectively select the optimal loading scheme but unable to utilize weight and volume capacity of cargo and truck. In this paper, we propose hybrid Genetic and fuzzy logic based cargo-loading decision making model that focus on achieving maximum profit with maximum utilization of weight and volume capacity of cargo and truck. In this paper, first of all, the components of the problem of goods stowage in the distribution center are analyzed systematically, which lays the foundation for the reasonable classification of the problem of goods stowage and the establishment of the mathematical model of the problem of goods stowage. Secondly, the paper abstracts and defines the problem of goods loading in distribution center, establishes the mathematical model for the optimization of single car three-dimensional goods loading, and designs the genetic algorithm for solving the model. Finally, Matlab is used to solve the optimization model of cargo loading, and the good performance of the algorithm is verified by an example. From the performance evaluation analysis, proposed the hybrid system achieve better outcomes than the standard SA model, GA method, and TS strategy.

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