Validation of Fingertip Force in the ACT Hand Index Finger and Bond Graph Tendon Model

2015 ◽  
Author(s):  
Raymond J. King ◽  
Taylor D. Niehues ◽  
Prashant Rao ◽  
Ashish D. Deshpande ◽  
Stephen A. Mascaro
Keyword(s):  
Index Finger ◽  
Graph Model ◽  
Cadaver Study ◽  
Bond Graph ◽  
Human Hand ◽  
Moment Arms ◽  
Cadaver Studies ◽  
The Moment ◽  
The Individual ◽  
Fingertip Forces

The Anatomically Correct Testbed (ACT) Hand was designed to allow researchers to explore the properties of the human hand without the need for cadaver specimens. Previous experiments to validate the anatomical accuracy of the ACT Hand have been performed to comparing the moment arms, the mechanical advantage of the tendons on each joint, to cadaver studies. Here, an experiment involving the individual tendon loading of the ACT index finger was performed as additional anatomical validation of the ACT Hand. These experiments were used to compare the ACT index finger to an index finger cadaver study and validate a bond graph model of the index finger tendon system. The results showed agreement (less than two standard deviations) between the fingertip forces of the ACT index finger and cadaver studies. The results also showed agreement (less than one standard deviation) between the fingertip forces of the ACT index finger and the presented bond graph tendon model.

scholarly journals Validity of Mechanical advantage hypothesis of human grasping depends on the nature of task difficulty

2021 ◽  
Author(s):  
Banuvathy Rajakumar ◽  
Swarnab Dutta ◽  
Varadhan SKM
Keyword(s):  
Center Of Mass ◽  
Tangential Force ◽  
Contact Forces ◽  
Human Hand ◽  
Mechanical Advantage ◽  
Moment Arms ◽  
The Central Nervous System ◽  
Constant Magnitude ◽  
The Individual ◽  
External Loads

Abstract Successful object interaction during daily living involves maintaining the grasped object in a static equilibrium by properly arranging the fingertip contact forces. According to the mechanical advantage hypothesis, during supination or pronation torque production, fingers with longer moment arms would produce greater normal force than those with shorter moment arms. Previous studies have probed this hypothesis by investigating the force contributions of the individual fingers through systematic variations (or perturbations) of properties of the grasped handle. In the current study, we examined the applicability of this hypothesis in a paradigm wherein the thumb tangential force was constrained to a minimal constant magnitude. This was achieved by placing the thumb on a freely movable slider platform. The total mass of the handle was systematically varied by adding external loads directly below the center of mass of the handle. Our findings suggest that in the human hand, the central nervous system (CNS) adopts the principle of mechanical advantage depending on an abstract sense of challenge attached to the task situation.

scholarly journals The biomechanics of trans-femoral amputation

1994 ◽  
Vol 18 (1) ◽  
pp. 12-17 ◽  
Author(s):  
F. A. Gottschalk ◽  
M. Stills
Keyword(s):  
Gait Cycle ◽  
Cadaver Study ◽  
Muscle Size ◽  
Dual Function ◽  
Loss Of Function ◽  
Moment Arms ◽  
Effective Moment ◽  
Adductor Magnus ◽  
Adductor Muscles ◽  
The Moment

The biomechanics of trans-femoral amputations has not been previously described. Little attention has been paid to the importance of adductor magnus in holding the femur in its normal anatomical axis. Loss of function of adductor magnus leads to abduction of the residual femur, in a trans-femoral amputation. A cadaver study of the adductor group of thigh muscles has been done and the biomechanical importance of these muscles is documented. The moment arms of the three adductor muscles have been determined, based on muscle attachments and muscle size, relative to each other. Adductor magnus has a major mechanical advantage in holding the thigh in its normal anatomical position. Loss of the distal third of its attachment results in a 70% loss of the effective moment arm of the muscle, which contributes to the abducted femur in standard trans-femoral amputations. A muscle preserving trans-femoral amputation, which keeps adductor magnus intact, prevents abduction of the residual femur and may allow for easier walking with a prosthesis. The conflicting reports about adductor magnus activity during the gait cycle can be explained by this muscle's dual innervation by the sciatic and obturator nerves and its dual function as a hip adductor and extensor.

Bond graph based control of a solar array

SIMULATION ◽  
2018 ◽  
Vol 94 (12) ◽  
pp. 1063-1080
Author(s):  
Roberto Tapia Sánchez ◽  
J. Aurelio Medina Ríos ◽  
Antonio Ramos Paz
Keyword(s):  
Control Structure ◽  
Graph Model ◽  
Bond Graph ◽  
Electrical Network ◽  
Solar Array ◽  
Control Law ◽  
Solar Panels ◽  
Structure Control ◽  
Park Transformation ◽  
The Individual

In this paper, the control of a solar array is proposed. The bond graph methodology is applied in order to get the structure control law for a solar array connected to the electrical network. For this, the different models of the complete system are presented. The solar array is built up by considering the individual solar panels. The inverter bond graph model is used for the development of the proposed control law. This model is inverted graphically to get the control structure. Also, the Park transformation concept is adapted to handle the control structure. This allows us to get a different control structure. Two different controls are considered in the proposed control structure, with their robustness tested for different power factors. The control law is tested using a real-time simulator. For this test, the rapid control prototyping concept is used. The obtained results demonstrate the viability of the proposed control law.

scholarly journals Electromyography Based Validation of a Musculoskeletal Hand Model

2021 ◽  
Author(s):  
Maximilian Melzner ◽  
Lucas Engelhardt ◽  
Ulrich Simon ◽  
Sebastian Dendorfer
Keyword(s):  
Model Building ◽  
Inverse Dynamics ◽  
Time Difference ◽  
Patient Specific ◽  
Human Hand ◽  
Moment Arms ◽  
Hand Model ◽  
Cadaver Studies ◽  
The Relationship ◽  
Musculoskeletal Simulations

Abstract Regarding the prevention of injuries and rehabilitation of the human hand, musculoskeletal simulations using an inverse dynamics approach allow for insights of the muscle recruitment and thus acting forces on the hand. Currently, several hand models from various research groups are in use, which are mainly validated by the comparison of numerical and anatomical moment arms. In contrast to this validation and model-building technique by cadaver studies, the aim of the present study is to further validate a recently published hand model [1] by analyzing numerically calculated muscle activities in comparison to experimentally measured electromyographical signals of the muscles. Therefore, the electromyographical signals of 10 hand muscles of five test subjects performing seven different hand movements were measured. The kinematics of these tasks were used as input for the hand model, and the numerical muscle activities were computed. To analyze the relationship between simulated and measured activities, the time difference of the muscle on- and off-set points were calculated, which resulted in a mean on- and off-set time difference of 0.58 s between the experimental data and the model. The largest differences were detected for movements that mainly addressed the wrist. One major issue comparing simulated and measured muscle activities of the hand is cross-talk. Nevertheless, the results show that the hand model fits the experiment quite accurately despite some limitations and is a further step towards patient-specific modelling of the upper extremity.

MOMENT ARMS OF THE ARM MUSCLES AT THE GLENOHUMERAL JOINT USING THE TENDON EXCURSION METHOD

2008 ◽  
Vol 11 (02) ◽  
pp. 45-53 ◽  
Author(s):  
Eiji Itoi ◽  
Seok-Beom Lee ◽  
Lawrence J. Berglund ◽  
Fredrick M. Schultz ◽  
Patricia G. Neale ◽  
...  
Keyword(s):  
Glenohumeral Joint ◽  
Moment Arm ◽  
Moment Arms ◽  
Individual Function ◽  
Arm Muscles ◽  
Long Head ◽  
The Moment ◽  
The Individual ◽  
External Rotator ◽  
Tendon Excursion

Muscle moment arm defines the function of the muscle. To date, moment arms of the arm muscles at the glenohumeral joint using the tendon excursion method have not been reported. As the functions of these muscles at the shoulder joint are controversial, this study was undertaken to determine the moment arms of the long and short heads of the biceps (LHB, SHB), the coracobrachialis, and the long head of the triceps muscles. The moment arms were determined in 10 cadaveric shoulders by measuring the tendon excursion when the arm was rotated by 1 radian (57.3°) in 22 different motions. The LHB was a flexor, horizontal flexor, and abductor. The SHB and coracobrachialis were flexors, horizontal flexors, and adductors. The long head of the triceps was an extensor and adductor. Arm rotation significantly affected the function of the LHB only: it was an internal rotator in flexion and an external rotator in abduction. This study clarifies the individual function of the arm muscles at the glenohumeral joint.

Bond graph model of a PEM fuel cell stack

2008 ◽  
Vol 1 (06) ◽  
pp. 329-334
Author(s):  
S. Rabih ◽  
C. Turpin ◽  
S. Astier
Keyword(s):  
Fuel Cell ◽  
Graph Model ◽  
Pem Fuel Cell ◽  
Bond Graph ◽  
Fuel Cell Stack

Erfahrung ohne Erfahrenden

2009 ◽  
Vol 2009 (1) ◽  
pp. 61-78
Author(s):  
Petr Kouba
Keyword(s):  
Phenomenological Approach ◽  
Work Of Art ◽  
New Beginning ◽  
Individual Structure ◽  
The World ◽  
Il Y A ◽  
Individual Existence ◽  
The Moment ◽  
The Individual ◽  
Intentional Structure

This article examines the limits of Heidegger’s ontological description of emotionality from the period of Sein und Zeit and Die Grundbegriffe der Metaphysik along the lines outlined by Lévinas in his early work De l’existence à l’existant. On the basis of the Lévinassian concept of “il y a”, we attempt to map the sphere of the impersonal existence situated out of the structured context of the world. However the worldless facticity without individuality marks the limits of the phenomenological approach to human existence and its emotionality, it also opens a new view on the beginning and ending of the individual existence. The whole structure of the individual existence in its contingency and finitude appears here in a new light, which applies also to the temporal conditions of existence. Yet, this is not to say that Heidegger should be simply replaced by Lévinas. As shows an examination of the work of art, to which brings us our reading of Moravia’s literary exposition of boredom (the phenomenon closely examined in Die Grundbegriffe der Metaphysik), the view on the work of art that is entirely based on the anonymous and worldless facticity of il y a must be extended and complemented by the moment in which a new world and a new individual structure of experience are being born. To comprehend the dynamism of the work of art in its fullness, it is necessary to see it not only as an ending of the world and the correlative intentional structure of the individual existence, but also as their new beginning.

Monkey on My Back. An Autoethnographic Narrative of a Therapeutic Experience

2020 ◽  
Author(s):  
Adam Wiesner
Keyword(s):  
Personal Experience ◽  
Meaning Making ◽  
The Self ◽  
Symbolic Language ◽  
Discursive Practices ◽  
Therapeutic Experience ◽  
Postmodern Philosophy ◽  
The Moment ◽  
The Individual ◽  
Global Uncertainty

With a conscious attempt to contribute to contemporary discussions in mad/trans/queer/monster studies, the monograph approaches complex postmodern theories and contextualizes them from an autoethnographic methodological perspective. As the self-explanatory subtitle reads, the book introduces several topics as revelatory fields for the author’s self-exploration at the moment of an intense epistemological and ontological crisis. Reflexively written, it does not solely focus on a personal experience, as it also aims at bridging the gap between the individual and the collective in times of global uncertainty. There are no solid outcomes defined; nevertheless, the narrative points to a certain—more fluid—way out. Through introducing alternative ways of hermeneutics and meaning-making, the book offers a synthesis of postmodern philosophy and therapy, evolutionary astrology as a symbolic language, embodied inquiry, and Buddhist thought that together represent a critical attempt to challenge the pathologizing discursive practices of modern disciplines during the neoliberal capitalist era.

scholarly journals Polymeric stents for the Eustachian tube: development and human cadaver study

2020 ◽  
Vol 6 (3) ◽  
pp. 213-216
Author(s):  
Kerstin Schümann ◽  
Tamara Wilfling ◽  
Gerrit Paasche ◽  
Robert Schuon ◽  
Thomas Lenarz ◽  
...  
Keyword(s):  
Eustachian Tube ◽  
Chronic Otitis Media ◽  
Cadaver Study ◽  
Human Cadaver ◽  
Tube Function ◽  
Human Cadavers ◽  
Radiopaque Markers ◽  
Cadaver Studies ◽  
Preclinical Safety ◽  
Human Cadaver Study

AbstractImpairment of Eustachian tube function with nonsufficient ventilation of the middle ear is a main cause for chronic otitis media. To provide an effective and safe therapy, the innovative concept of Eustachian tube stenting was established. Biodegradable polymeric stents are developed to restore impaired tube function and dissolve after fulfilling their supportive purpose. To evaluate the applicability of the stents in the Eustachian tube, prototypes in conjunction with corresponding implantation instruments were tested in human cadaver studies. Radiopaque markers and a diaphanoscopic approach were tested as additional features to prove correct positioning of catheter and stent in the tube. In the current study biodegradable polymeric stents were implanted in the Eustachian tube of human cadavers without difficulty. Correct positioning of the stents in the tube was proved by diaphanoscopy during intervention and postoperative tomographic and histological analyses. Once designs are optimized on the basis of cadaver studies, preclinical safety and efficacy studies using animal models will be initiated.

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