Development of a Dexterous Prosthetic Hand

Author(s):  
Mahonri Owen ◽  
ChiKit Au ◽  
Andrew Fowke

An anthropomorphic, under-actuated, prosthetic hand has been designed and developed for upper extremity amputees. This paper proposes a dexterity focused approach to the design of an anthropomorphic electromechanical hand for transradial amputees. Dexterity is increased by the improvement of thumb position, orientation, and work space. The fingers of the hand are also capable of adduction and abduction. It is the intent of this research project to aid the rehabilitation of upper extremity amputees by increasing the amount of tasks the hand can execute. Function and control of the hand are based on micro servo actuation and information acquired from the brain. Electroencephalography (EEG) is used to attain the mental state of the user, which triggers the prosthetic hand. This paper focuses on the mechanical arrangement of the hand and investigates the effect of increasing the degrees-of-freedom (DOFs) the thumb and fingers have.

Athenea ◽  
2020 ◽  
Vol 1 (1) ◽  
pp. 22-28
Author(s):  
Oscar Vargas ◽  
Omar Flor ◽  
Carlos Toapanta

In this work, the design of a robotic hand with 7 degrees of freedom is presented that allows greater flexibility, achieving the usual actions performed by a normal hand. The work consists of a prototype designed with linear actuators and myoelectric sensor, following the mechanism of the University of Toronto for the management of functional phalanges. The design, construction description, components and recommendations for the elaboration of a flexible and useful robotic hand for amputee patients with a residual limb for the socket are presented. Keywords: Robotic hand, Degree of freedom, Toronto´s Mechanism, lineal actuator. References [1]W. Diane, J. Braza and M. Yacub, Essentials of Physical Medicine and Rehabilitation, 4th ed. Philadelphia: Walter R. Frontera and Julie K. Silver and Thomas D. Rizzo, 2020, pp. 651 - 657. [2]A. Heerschop, C. Van Der Sluis, E. Otten, & R.M. Bongers, Looking beyond proportional control: The relevance of mode switching in learning to operate multi-articulating myoelectric upper-limb prostheses, . Biomedical Signal Processing and Control, 2020, doi:10.1016/j.bspc.2019.101647. [3]L. Heisnam, B. Suthar, 20 DOF robotic hand for tele-operation: — Design, simulation, control and accuracy test with leap motion. 2016 International Conference on Robotics and Automation for Humanitarian Applications (RAHA), 2016, doi:10.1109/raha.2016.7931886. [4]Y. Mishima, R. Ozawa, Design of a robotic finger using series gear chain mechanisms. 2014 IEEE/RSJ International Conference on Intelligent Robots and Systems, 2014, doi:10.1109/iros.2014.6942961. [5]N. Dechev, W. Cleghorn, S. Naumann, Multi-segmented finger design of an experimental prosthetic hand,Proceedings of the Sixth National Applied Mechanisms & Robotics Conference, december 1999. [6]O. Flor, “Building a mobile robot,” Education for the future. Accessed on: December 29, 2019. [Online] Available: https://omarflor2014.wixsite.com/misitio. [7]Vargas, O., Flor,O., Suarez, F., Design of a robotic prototype of the hand and right forearm for prostheses, Universidad, Ciencia y Tecnología, 2019. [8]O. Vargas, O. Flor, F. Suarez, C. Chimbo, Construction and functional tests of a robotic prototype for human prostheses, Revista espirales, 2020. [9]P. PonPriya, E. Priya, Design and control of prosthetic hand using myoelectric signal. International Conference on Computing and Communications Technologies (ICCCT), 2017, doi:10.1109/iccct2.2017.7972314. [10]N. Bajaj, A. Spiers, A. Dollar, State of the Art in Artificial Wrists: A Review of Prosthetic and Robotic Wrist Design. IEEE Transactions on Robotics, 2019, doi:10.1109/tro.2018.2865890.


2001 ◽  
Author(s):  
Bradley Olson ◽  
Leonard Jason ◽  
Joseph R. Ferrari ◽  
Leon Venable ◽  
Bertel F. Williams ◽  
...  

Author(s):  
Burbaeva G.Sh. ◽  
Androsova L.V. ◽  
Vorobyeva E.A. ◽  
Savushkina O.K.

The aim of the study was to evaluate the rate of polymerization of tubulin into microtubules and determine the level of colchicine binding (colchicine-binding activity of tubulin) in the prefrontal cortex in schizophrenia, vascular dementia (VD) and control. Colchicine-binding activity of tubulin was determined by Sherlinе in tubulin-enriched extracts of proteins from the samples. Measurement of light scattering during the polymerization of the tubulin was carried out using the nephelometric method at a wavelength of 450-550 nm. There was a significant decrease in colchicine-binding activity and the rate of tubulin polymerization in the prefrontal cortex in both diseases, and in VD to a greater extent than in schizophrenia. The obtained results suggest that not only in Alzheimer's disease, but also in other mental diseases such as schizophrenia and VD, there is a decrease in the level of tubulin in the prefrontal cortex of the brain, although to a lesser extent than in Alzheimer's disease, and consequently the amount of microtubules.


2020 ◽  
pp. 67-73
Author(s):  
N.D. YUsubov ◽  
G.M. Abbasova

The accuracy of two-tool machining on automatic lathes is analyzed. Full-factor models of distortions and scattering fields of the performed dimensions, taking into account the flexibility of the technological system on six degrees of freedom, i. e. angular displacements in the technological system, were used in the research. Possibilities of design and control of two-tool adjustment are considered. Keywords turning processing, cutting mode, two-tool setup, full-factor model, accuracy, angular displacement, control, calculation [email protected]


Cells ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 134
Author(s):  
Stephanie Dooves ◽  
Arianne J. H. van Velthoven ◽  
Linda G. Suciati ◽  
Vivi M. Heine

Tuberous sclerosis complex (TSC) is a genetic disease affecting the brain. Neurological symptoms like epilepsy and neurodevelopmental issues cause a significant burden on patients. Both neurons and glial cells are affected by TSC mutations. Previous studies have shown changes in the excitation/inhibition balance (E/I balance) in TSC. Astrocytes are known to be important for neuronal development, and astrocytic dysfunction can cause changes in the E/I balance. We hypothesized that astrocytes affect the synaptic balance in TSC. TSC patient-derived stem cells were differentiated into astrocytes, which showed increased proliferation compared to control astrocytes. RNA sequencing revealed changes in gene expression, which were related to epidermal growth factor (EGF) signaling and enriched for genes that coded for secreted or transmembrane proteins. Control neurons were cultured in astrocyte-conditioned medium (ACM) of TSC and control astrocytes. After culture in TSC ACM, neurons showed an altered synaptic balance, with an increase in the percentage of VGAT+ synapses. These findings were confirmed in organoids, presenting a spontaneous 3D organization of neurons and glial cells. To conclude, this study shows that TSC astrocytes are affected and secrete factors that alter the synaptic balance. As an altered E/I balance may underlie many of the neurological TSC symptoms, astrocytes may provide new therapeutic targets.


2021 ◽  
pp. 074880682110310
Author(s):  
Angelo Cuzalina ◽  
Pasquale G. Tolomeo

The aim of this study was to determine the efficacy of cool atmospheric plasma (Renuvion/J-plasma) in promoting skin tightening and soft tissue contouring following liposuction of the upper extremities. The study was a retrospective review of upper extremity liposuction with associated Renuvion therapy performed by the same surgeon. Patients were made aware of Renuvion therapy to assist with skin laxity and offered adjunctive treatment following liposuction. While a majority of patients elected to have Renuvion therapy performed bilaterally, a small subset of patients elected for unilateral treatment. This subset of patients pursued delayed treatment on the control side. The inclusion criteria for the study included patients with moderate fat excess of the upper extremity with associated mild to moderate cutaneous laxity. Exclusion criteria for the study included severe medical comorbidities, body mass index greater than 35 kg/m2 and those below the age of 30. The study included 5 female patients between the ages of 46 to 52. The method of treatment was liposuction of the bilateral upper extremities with removal of equal proportions of fat. The recipient site for Renuvion treatment was randomly selected by the study coordinator; the surgeon and clinical staff remained blinded to the selection. Following treatment, the patients were evaluated at 1 week, 6 weeks, and 6 months postoperatively to assess surgical outcomes subjectively. The surgeon and clinical staff were unblinded at the final visit. Patients were evaluated based on subjective criteria and photographic evaluation at each postoperative visit. At the 1-week visit, no significant differences were noted in all subjects. At the 6-week visit, two patients demonstrated improved results to the treatment site when compared with the control site. At the 6-month visit, four out of the five patients demonstrated a significant improvement in contour and laxity at the treatment site when compared with the control site. One patient demonstrated equal results on both treatment and control sites with no major abnormalities. Following the final evaluation, the patients underwent a secondary procedure to the control site with Renuvion to obtain similar results as the recipient site. One patient demonstrated equal results on both test and control sites with no major abnormalities. The use of plasma energy via Renuvion in conjunction with liposuction has demonstrated esthetic results with proposed long-term benefits. The plasma energy device, as an adjuvant therapy, may be beneficial in cases where liposuction alone may not address tissue laxity concerns. Additional studies with a larger sample size, objective criteria, and extended follow-ups are necessary to statistically analyze the results and determine its significance.


Sensors ◽  
2020 ◽  
Vol 21 (1) ◽  
pp. 137
Author(s):  
Larisa Dunai ◽  
Martin Novak ◽  
Carmen García Espert

The present paper describes the development of a prosthetic hand based on human hand anatomy. The hand phalanges are printed with 3D printing with Polylactic Acid material. One of the main contributions is the investigation on the prosthetic hand joins; the proposed design enables one to create personalized joins that provide the prosthetic hand a high level of movement by increasing the degrees of freedom of the fingers. Moreover, the driven wire tendons show a progressive grasping movement, being the friction of the tendons with the phalanges very low. Another important point is the use of force sensitive resistors (FSR) for simulating the hand touch pressure. These are used for the grasping stop simulating touch pressure of the fingers. Surface Electromyogram (EMG) sensors allow the user to control the prosthetic hand-grasping start. Their use may provide the prosthetic hand the possibility of the classification of the hand movements. The practical results included in the paper prove the importance of the soft joins for the object manipulation and to get adapted to the object surface. Finally, the force sensitive sensors allow the prosthesis to actuate more naturally by adding conditions and classifications to the Electromyogram sensor.


Author(s):  
Alireza Marzbanrad ◽  
Jalil Sharafi ◽  
Mohammad Eghtesad ◽  
Reza Kamali

This is report of design, construction and control of “Ariana-I”, an Underwater Remotely Operated Vehicle (ROV), built in Shiraz University Robotic Lab. This ROV is equipped with roll, pitch, heading, and depth sensors which provide sufficient feedback signals to give the system six degrees-of-freedom actuation. Although its center of gravity and center of buoyancy are positioned in such a way that Ariana-I ROV is self-stabilized, but the combinations of sensors and speed controlled drivers provide more stability of the system without the operator involvement. Video vision is provided for the system with Ethernet link to the operation unit. Control commands and sensor feedbacks are transferred on RS485 bus; video signal, water leakage alarm, and battery charging wires are provided on the same multi-core cable. While simple PI controllers would improve the pitch and roll stability of the system, various control schemes can be applied for heading to track different paths. The net weight of ROV out of water is about 130kg with frame dimensions of 130×100×65cm. Ariana-I ROV is designed such that it is possible to be equipped with different tools such as mechanical arms, thanks to microprocessor based control system provided with two directional high speed communication cables for on line vision and operation unit.


1997 ◽  
Vol 9 (6) ◽  
pp. 699-713 ◽  
Author(s):  
Stephan B. Hamann ◽  
Larry R. Squire

Recent studies have challenged the notion that priming for ostensibly novel stimuli such as pseudowords (REAB) reflects the creation of new representations. Priming for such stimuli could instead reflect the activation of familiar memory representations that are orthographically similar (READ) and/or the activation of subparts of stimuli (RE, EX, AR), which are familar because they occur commonly in English. We addressed this issue in three experiments that assessed perceptual identification priming and recognition memory for novel and familiar letter strings in amnesic patients and control subjects. Priming for words, pseudowords, and orthographically illegal nonwords was fully intact in the amnesic patients following a single exposure, whereas recognition memory was impaired for the same items. Thus, priming can occur for stimuli that are unlikely to have preexisting representations. Words and pseudowords exhibited twice as much priming as illegal nonwords, suggesting that activation may contribute to priming for words and wordlike stimuli. Additional results showed that priming for illegal nonwords resulted from the formation of new perceptual associations among the component letters of each nonword rather than the activation of individual letter representations. In summary, the results demonstrate that priming following a single exposure can depend on the creation of new perceptual representations and that such priming is independent of the brain structures essential for declarative memory.


Author(s):  
Lee-Huang Chen ◽  
Kyunam Kim ◽  
Ellande Tang ◽  
Kevin Li ◽  
Richard House ◽  
...  

This paper presents the design, analysis and testing of a fully actuated modular spherical tensegrity robot for co-robotic and space exploration applications. Robots built from tensegrity structures (composed of pure tensile and compression elements) have many potential benefits including high robustness through redundancy, many degrees of freedom in movement and flexible design. However to fully take advantage of these properties a significant fraction of the tensile elements should be active, leading to a potential increase in complexity, messy cable and power routing systems and increased design difficulty. Here we describe an elegant solution to a fully actuated tensegrity robot: The TT-3 (version 3) tensegrity robot, developed at UC Berkeley, in collaboration with NASA Ames, is a lightweight, low cost, modular, and rapidly prototyped spherical tensegrity robot. This robot is based on a ball-shaped six-bar tensegrity structure and features a unique modular rod-centered distributed actuation and control architecture. This paper presents the novel mechanism design, architecture and simulations of TT-3, the first untethered, fully actuated cable-driven six-bar tensegrity spherical robot ever built and tested for mobility. Furthermore, this paper discusses the controls and preliminary testing performed to observe the system’s behavior and performance.


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