scholarly journals A Sequential Approach to the Biodynamic Modeling of a Human Finger

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Luka Knez ◽  
Janko Slavič ◽  
Miha Boltežar
Keyword(s):  
Mechanical Model ◽  
Index Finger ◽  
Simulated Data ◽  
Body Parts ◽  
Sequential Approach ◽  
Novel Device ◽  
Single Finger ◽  
Mechanical Models ◽  
Human Finger ◽  
Finger Model

In an effort to understand the vibration-induced injuries incurred by manual workers, mechanical models are developed and used to predict the biodynamic responses of human body parts that are exposed to vibration. Researchers have traditionally focused on the arms and hands, but there has been only limited research on finger modeling. To simulate the accurate response of a single finger, a detailed mechanical model based on biodynamic finger measurements is necessary. However, the development of such models may prove difficult using the traditional one-point coupling method; therefore, this study proposes a new approach. A novel device for single-finger measurements is presented and used to expose the finger to a single-axial broadband excitation. The sequentially measured responses of the different finger parts are then used to identify the parameters of a multibody mechanical model of the index finger. Very good agreement between the measured and the simulated data was achieved, and the study also confirmed that the obtained index-finger model is acceptable for further biodynamic studies.

Study of Sand Production Using Geomechanical and Hydro-Mechanical Models

2018 ◽  
Vol 876 ◽  
pp. 181-186
Author(s):  
Son Tung Pham
Keyword(s):  
Production Rate ◽  
Mechanical Model ◽  
Failure Criteria ◽  
Sand Production ◽  
Geomechanical Model ◽  
Strength Failure ◽  
Rate Versus ◽  
Mechanical Models ◽  
Rock Mechanical Properties ◽  
Bottomhole Pressure

Sand production is a complicated physical process depending on rock mechanical properties and flow of fluid in the reservoir. When it comes to sand production phenomenon, many researchers applied the Geomechanical model to predict the pressure for the onset of sand production in the reservoir. However, the mass of produced sand is difficult to determine due to the complexity of rock behavior as well as fluid behavior in porous media. In order to solve this problem, there are some Hydro – Mechanical models that can evaluate sand production rate. As these models require input parameters obtained by core analysis and use a large empirical correlation, they are still not used popularly because of the diversity of reservoirs behavior in the world. In addition, the reliability of these models is still in question because no comparison between these empirical models has been studied. The onset of sand production is estimated using the bottomhole pressure that makes the maximum effective tangential compressive stress equal or higher than the rock strength (failure criteria), which is usually known as critical bottomhole pressure (CBHP). Combining with Hydro – Mechanical model, the main objective of this work aims to develop a numerical model that can solve the complexity of the governing equations relating to sand production. The outcome of this study depicts sand production rate versus time as well as the change of porosity versus space and time. In this paper, the Geomechanical model coupled with Hydro – Mechanical model is applied to calibrate the empirical parameters.

scholarly journals Finite element analysis to assess the biomechanical behavior of a finger model gripping handles with different diameters

2019 ◽  
Vol 11 (1) ◽  
pp. 69-79 ◽  
Author(s):  
Benedict Jain A.R. Tony ◽  
Masilamany S. Alphin
Keyword(s):  
Finite Element ◽  
Contact Pressure ◽  
Subcutaneous Tissue ◽  
Fe Model ◽  
Stress Strain ◽  
Element Analysis ◽  
Biomechanical Behavior ◽  
Biomechanical Response ◽  
Human Finger ◽  
Finger Model

SummaryStudy aim: Interactions between the fingers and a handle can be analyzed using a finite element finger model. Hence, the biomechanical response of a hybrid human finger model during contact with varying diameter cylindrical handles was investigated numerically in the present study using ABAQUS/CAE.Materials and methods: The finite element index finger model consists of three segments: the proximal, middle, and distal phalanges. The finger model comprises skin, bone, subcutaneous tissue and nail. The skin and subcutaneous tissues were assumed to be non-linearly elastic and linearly visco-elastic. The FE model was applied to predict the contact interaction between the fingers and a handle with 10 N, 20 N, 40 N and 50 N grip forces for four different diameter handles (30 mm, 40 mm, 44mm and 50 mm). The model predictions projected the biomechanical response of the finger during the static gripping analysis with 200 incremental steps.Results: The simulation results showed that the increase in contact area reduced the maximal compressive stress/strain and also the contact pressure on finger skin. It was hypothesized in this study that the diameter of the handle influences the stress/strain and contact pressure within the soft tissue during the contact interactions.Conclusions: The present study may be useful to study the behavior of the finger model under the static gripping of hand-held power tools.

Design of Workspace of Human Fingers and Computer Keyboard Operation

2014 ◽  
Vol 484-485 ◽  
pp. 1118-1125
Author(s):  
Rao Shun
Keyword(s):  
Degrees Of Freedom ◽  
Index Finger ◽  
Operation Mode ◽  
Penalty Function Method ◽  
Three Dimension ◽  
Mechanism Model ◽  
Reachable Workspace ◽  
Human Arm ◽  
Dimension Space ◽  
Human Finger

There are more and more complex tools and machinery that need be operated by human fingers in our modem industrial environment. Such as computer keyboards, screwdriver, handle wrench, button and switch. All of those should be designed to work effectively and safely with the operators for whom they were designed. At first, ergonomic consideration in design is reachable; this means the operators fingertip must be able to reach the operating component. This is generally no question because human arm has much more degrees of freedom required to position his arms, hands and fingers in the three-dimension space. However, some times we need the finger operate with a fixed wrist. For example in the case in the typing, the reachable workspace of the finger must take into account in such situation.Finger contacting is the most familiar operation mode of the man-machine system, and the index finger takes on the primary operation tasks. From viewpoint of ergonomic engineering, the operation component should be placed within the workspace of the fingertip to reduced or eliminate the movement of palm and arm should to the greatest extent during finger manipulation. Therefore the research of the workspace of ginger is significant to the ergonomic design of the operation device. In this paper, the reachable workspace and workspace under direction restrain of contacting for the index finger are determined using serial mechanism model and the Penalty Function Method based on geometric measurement of human body. The optimal operating position and orientation of human finger is analyzed.

Some Properties of a Mechanical Model of Plasticity

1948 ◽  
Vol 15 (3) ◽  
pp. 222-225
Author(s):  
H. F. Bohnenblust ◽  
Pol Duwez
Keyword(s):  
Plastic Deformation ◽  
Potential Energy ◽  
Work Hardening ◽  
Mechanical Model ◽  
Strain Curve ◽  
Hysteresis Curve ◽  
Plastic Range ◽  
Stress Strain Curve ◽  
Stress Strain ◽  
Mechanical Models

Abstract Various mechanical models explaining the plastic deformation of metals have been proposed. One of the present authors has shown that in some cases an analytical expression for the stress-strain curve and the hysteresis curve of a metal in the plastic range can be deduced from such a model. The present investigation is a further analysis of the model leading to the computation of the change in potential energy of the metal due to work-hardening.

scholarly journals Research on finger movement sensing performance of conductive gloves

2019 ◽  
Vol 14 ◽  
pp. 155892501988762 ◽  
Author(s):  
Xiaoxue Han ◽  
Xuhong Miao ◽  
Xi Chen ◽  
Gaoming Jiang ◽  
Li Niu
Keyword(s):  
Index Finger ◽  
Dynamic Test ◽  
Rehabilitation Medicine ◽  
Proximal Interphalangeal Joint ◽  
Knitted Fabric ◽  
Resistance Change ◽  
Flexible Sensors ◽  
Finger Motion ◽  
Human Finger ◽  
Resistance Data

Knitted flexible sensors are sensors based on the loop structure of knitted fabric, which are soft and close-fitting. Monitoring finger motion can obtain useful information for some applications such as rehabilitation medicine, sports bionics, or human–computer interaction. In this paper, a conductive glove was knitted by SHIMA Seiki SWG 061N-15G computerized flat knitting machine. One experimenter wore it to measure motions data of index finger. The glove has a conductive intarsia area knitted by silver-nylon filaments. The experimenter performed static and dynamic test of hand posture, respectively, then observed the effect of figure bending characteristics on the glove resistance data. The result showed that human finger motion can be monitored successfully by the conductive glove without hard transducers, and both of the bending rate ( Br) and bending angle of the finger proximal interphalangeal joint ( Pba) affect the resistance change of the conductive area of the glove. In other words, the conductive glove has potentials to monitor and reflect human finger motions in detail.

scholarly journals A First Optimal Control Solution for a Complex, Nonlinear, Tendon Driven Neuromuscular Finger Model

2010 ◽  
Author(s):  
Evangelos A. Theodorou ◽  
Emo Todorov ◽  
Francisco J. Valero-Cuevas
Keyword(s):  
Optimal Control ◽  
Muscle Force ◽  
Index Finger ◽  
Feedback Controller ◽  
Extensor Mechanism ◽  
High Dimensionality ◽  
Control Solution ◽  
Force Velocity ◽  
Finger Model ◽  
Robust To Noise

In this work we present the first constrained stochastic optimal feedback controller applied to a fully nonlinear, tendon driven index finger model. Our model also takes into account an extensor mechanism, and muscle force-length and force-velocity properties. We show this feedback controller is robust to noise and perturbations to the dynamics, while successfully handling the nonlinearities and high dimensionality of the system. By extending prior methods, we are able to approximate physiological realism by ensuring positivity of neural commands and tendon tensions at all times.

scholarly journals PROSTHETIC REHABILITATION OF EXTRA-ORAL DEFECTS WITH SILICONE PROSTHESIS

2012 ◽  
Vol 02 (04) ◽  
pp. 12-15
Author(s):  
Harshitha Alva ◽  
Krishna Prasad D. ◽  
Manoj Shetty
Keyword(s):  
Index Finger ◽  
Left Index Finger ◽  
Body Parts ◽  
Prosthetic Rehabilitation ◽  
Silicone Prosthesis ◽  
Normal Life ◽  
Facial Defects ◽  
Custom Made ◽  
The Ideal

AbstractMan's need for artificial replacements to supply missing or lost body parts has probably existed as long as man himself. Body abnormalities or defects compromise appearance, function and render an individual incapable of leading a relatively normal life. Extraoral defects involving ear, eye, nose, finger and few others are commonly encountered. Prosthetic restoration of these facial defects is an ancient art, in which success has always been limited due to the unavailability of adequate materials or because the available materials do not fulfil the ideal requirements. The most accepted materials today are the silicones because of their better esthetics.This paper presents prosthetic rehabilitation of the distal phalynx of left index finger with custom-made silicone prosthesis.

Identification of the Mechanical Impedance at the Human Finger Tip

1997 ◽  
Vol 119 (1) ◽  
pp. 109-114 ◽  
Author(s):  
A. Z. Hajian ◽  
R. D. Howe
Keyword(s):  
Linear Model ◽  
Muscle Activation ◽  
Index Finger ◽  
Damping Ratio ◽  
Mechanical Impedance ◽  
Order Linear ◽  
Human Finger ◽  
Rapid Transients ◽  
Finger Tip ◽  
Tip Mass

Rapid transients were applied to the outstretched human index finger tip, which resulted in motion primarily at the metacarpophalangeal (MCP) joint in extension and in abduction. A second-order linear model was fit to approximately 20 milliseconds of the force and displacement data to determine the effective mechanical impedance at the finger tip. Ranges of mass, damping, and stiffness parameters were estimated over a range of mean finger tip force (2–20 N for extension, 2–8 N for abduction). Effective translational finger tip mass for each subject was relatively constant for force levels greater than 6 N for extension, and constant throughout the abduction trials. Stiffness increased linearly with muscle activation. The estimated damping ratio for extension trials was about 1.7 times the ratio for abduction.

Anthropomorphic Optimization of a Rope-Driven Prosthetic Finger

2014 ◽  
Vol 568-570 ◽  
pp. 899-903 ◽  
Author(s):  
Qun Ming Li ◽  
Yao Wen Li
Keyword(s):  
Index Finger ◽  
Optimization Method ◽  
Spring Stiffness ◽  
Joint Angles ◽  
Data Glove ◽  
Prosthetic Finger ◽  
Human Finger ◽  
The Relationship

In consideration of the importance of the prosthetic finger having the motion law of human finger. We first establish the relationship between spring stiffness and joint angles of the prosthetic finger through the analysis of the prosthetic finger kinematic. Then collect the joint angles of human index finger during natural bending by using the CyberGloveII-22 data glove. Based on this, an anthropomorphic optimization method is proposed in order to let the prosthetic dinger have the motion law of human index finger. The method in this paper can also be used to plan the trajectory of the finger.

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