Skin and Bone Surfaces for a Three-Dimensional Kinematic Hand Model

2009 ◽  
Author(s):  
Daewoo Park ◽  
Thomas J. Armstrong ◽  
Charles B. Woolley ◽  
Christopher J. Best
Keyword(s):  
Three Dimensional ◽  
Hand Model

Skin and Bone Surfaces for a Three-Dimensional Kinematic Hand Model

2009 ◽  
Vol 53 (18) ◽  
pp. 1225-1229
Author(s):  
Daewoo Park ◽  
Thomas J. Armstrong ◽  
Charles B. Woolley ◽  
Christopher J. Best
Keyword(s):  
Three Dimensional ◽  
Hand Model

CFD Analysis of Current-Induced Loads on Large Caisson at Supercritical Reynolds Number

2004 ◽  
Vol 127 (2) ◽  
pp. 104-111 ◽  
Author(s):  
Subrata K. Chakrabarti ◽  
Kristian K. Debus ◽  
Jonathan Berkoe ◽  
Brigette Rosendall
Keyword(s):  
Reynolds Number ◽  
Model Test ◽  
Three Dimensional ◽  
Computational Method ◽  
Cfd Analysis ◽  
Hand Model ◽  
Fixed Model ◽  
The Difference ◽  
High Reynolds ◽  
Cfd Method

The newly constructed Tacoma Narrows Bridge Piers represent large concrete floating caissons during their construction. For designing their mooring system the current force applied on the caissons in the Narrows must be known. The flow field around the caisson is highly complex and the calculation of the current load on the caisson by analytical means is difficult. On the other hand, model tests suffer from the distortion in the Reynolds number. Therefore, a two-prong approach was undertaken. Besides the fixed model test of the caissons for current forces, a CFD analysis of the flow around the caisson is chosen. A three-dimensional CFD approach is considered more appropriate than a two-dimensional one, since the bottom contour at the site is irregular and water depth is rather shallow. This paper discusses the CFD method and the results obtained from such analysis. The numerical analysis was carried out in both ebb and flood flow of the tidal current in the basin. One of the difficulties of the computational method is the very high Reynolds number encountered by the large current and large size of the caisson. The analysis is performed in both model and full scales so that the difference in the results may be investigated. Also, since the model test data are available, comparisons are made between the CFD and model test results on the drag and lift forces on the caisson.

Comparison Between Healthy and Reduced Hand Function Using Ranges of Motion and a Weighted Fingertip Space Model

2015 ◽  
Vol 137 (4) ◽  
Author(s):  
Samuel T. Leitkam ◽  
Tamara Reid Bush
Keyword(s):  
Dimensional Space ◽  
Hand Function ◽  
Three Dimensional ◽  
Loss Of Function ◽  
Healthy Individuals ◽  
Model Calculations ◽  
Hand Model ◽  
Functional Models ◽  
Distal Interphalangeal ◽  
The Individual

Detection and quantification of changes in hand function are important for patients with loss of function and clinicians who are treating them. A recently developed model, the weighted fingertip space (WFS) quantifies the hand function of individuals in three-dimensional space and applies kinematic weighting parameters to identify regions of reachable space with high and low hand function. The goal of this research was to use the WFS model to compare and contrast the functional abilities of healthy individuals with the abilities of individuals with reduced functionality due to arthritis (RFA). Twenty two individuals with no reported issues with hand function and 21 individuals with arthritis affecting the hand were included in the research. Functional models were calculated from the ranges of motion and hand dimension data for each individual. Each model showed the volume of reachable space for each fingertip of each hand, the number of ways to reach a point in space, the range of fingertip orientations possible at each point, and the range of possible force application directions (FADs) at each point. In addition, two group models were developed that showed how many individuals in both the healthy and RFA groups were able to reach the same points in space. The results showed differences between the two groups for the range of motion (ROM) measurements, the individual model calculations, and the group models. The ROM measurements showed significant differences for the joints of the thumb, extension of the nonthumb metacarpophalangeal (MCP) joints, and flexion of the distal interphalangeal (DIP) joints. Comparing the models, the two groups qualitatively showed similar patterns of functional measures in space, but with the RFA group able to reach a smaller volume of space. Quantitatively, the RFA group showed trends of smaller values for all of the calculated functional weighting parameters and significantly smaller reachable volume for all of the fingers. The group models showed that all healthy individuals were able to reach an overlapping space, while 18 of 21 RFA individuals were able to reach similar spaces. Combined, the results showed that the WFS model presents the abilities of the hand in ways that can be quantitatively and qualitatively compared. Thus, the potential of this hand model is that it could be used to assess and document the changes that occur in hand function due to rehabilitation or surgery, or as a guide to determine areas most accessible by various populations.

scholarly journals Finite element analysis of the flexor digitorum profundus tendon during a passive rehabilitation protocol

2021 ◽  
Author(s):  
Oliver Grimaldo-Ruiz ◽  
Mariana Rodríguez-Reinoso ◽  
Cecilia Surace
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Maximum Principal Stress ◽  
Flexor Digitorum Profundus ◽  
Patient Specific ◽  
Element Analysis ◽  
Hand Model ◽  
Online Library ◽  
Flexor Digitorum ◽  
Tendon Excursion

The present study aims to create a patient-specific hand model to simulate the passive rehabilitation on the index finger, quantifying the flexor digitorum profundus (FDP) tendon excursion and the stress experienced during simulated flexion. The computational model used in this analysis was created from an unknown patient dataset available in the Embodi3d online library. The segmentation, three-dimensional reconstruction, and modeling of the structures involved were performed using Materialise Mimics and Rhino3D. The FDP tendon excursion and stress values present in the model were calculated in the ANSYS environment. Based on the finite-element simulation, the FDP tendon presents an excursion of 10.1 mm during passive postoperative flexion. The highest-stress values were observed between the pulleys-FDP tendon contact surfaces. In particular, the pulley A1 exhibited the maximum principal stress of the model with a 58.7 MPa.  The pulley A3 showed the same stress distribution pattern that A1 Pulley, but with the lowest values. The FDP Tendon excursion obtained is consistent with the results reported in the literature, which vary from 8 to 11 mm. The stress values found in the model explain the importance of the pulley mechanism keeping the FDP tendon attached to the finger bone during the range of motion experienced. The silico model proposed may potentially be used in the assessment of new medical device proposals in the field of hand reconstructive surgery.

A Novel Suction-and-Irrigation Laparoscopic Surgical Instrument: Internal Design and Preclinical Performance Evaluation

2021 ◽  
Author(s):  
Sang Wook Yi
Keyword(s):  
Three Dimensional ◽  
The Other ◽  
Suction Catheter ◽  
Surgical Instrument ◽  
Preventive Effect ◽  
Side Hole ◽  
Hand Model ◽  
Catheter Tip ◽  
Preclinical Efficacy ◽  
Printer Model

Abstract Objective: Laparoscopic instruments with suction and irrigation functions often lead to tissue damage during removal of the aspirated tissues, owing to the presence of aspiration into the side holes of their catheters. To address this problem, we designed a novel irrigation-and-suction catheter and assessed its preclinical efficacy. Methods: We made structural improvements to the irrigation-suction catheter to prevent tissue aspiration through its side holes. We ran a simulation program to perform experimental assessments before printing out the catheter tip models using a three-dimensional printer. Model 1 was the control, and Models 2, 3, and 4 were the improved models. Using these, we performed 10 repetitions of 15-s suction followed by 15-s irrigation, for a total of 5 times per model. We recorded the number of aspirations that occurred through the side holes and analyzed each model using nonparametric methods. Results: Models 2 and 3 showed fewer aspirations because the velocity and pressure around their side holes were lower than those of Model 1; this was statistically significant. On the other hand, Model 4 had a lesser preventive effect against aspiration due to higher velocity and pressure around its side holes. Conclusion: We confirmed that side-hole aspiration can be prevented with an internal structure that completely separates the irrigation and suction paths. Even if the irrigation and suction paths are not completely separated, adding a septal structure at the distal end of the catheter may prevent aspiration.

Development of a three-dimensional hand model using 3D stereophotogrammetry: Evaluation of landmark reproducibility

2015 ◽  
Vol 68 (5) ◽  
pp. 709-716 ◽  
Author(s):  
Inge A. Hoevenaren ◽  
Thomas J.J. Maal ◽  
E. Krikken ◽  
A.F.J. de Haan ◽  
S.J. Bergé ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Hand Model ◽  
3D Stereophotogrammetry

scholarly journals Bounded Responsibility and Bounded Ethics of Science and Technology

Axiomathes ◽  
2020 ◽  
Vol 30 (6) ◽  
pp. 597-616
Author(s):  
Günter Abel
Keyword(s):  
Reflective Equilibrium ◽  
Human Life ◽  
Science And Technology ◽  
Three Dimensional ◽  
Ethical Argument ◽  
Hand Model ◽  
Ethics Of Science ◽  
Life On Earth ◽  
Challenging Question ◽  
Leading Question

Abstract The leading question of this paper is: Where does the normativity of the ethics of science and technology come from? This is a challenging question given that the traditional reservoirs of convenience (like metaphysical universalism) are no longer at our disposal the way they used to be. The paper is divided into eight sections: (1) It is specified what challenges a non-foundationalist justification and normativity has to meet. (2) A three-dimensional conception of responsibility is developed based on the human triangular I–We–World relations. (3) The concepts of bounded responsibility and bounded ethics of science and technology are formulated. (4) The principle of reflective equilibrium is introduced as a principle of rationality, and it is shown how this principle generates rational and reasonable justifications in the ethics of science and technology. (5) Against this background, a reconception of internal and external responsibilities of science is given. (6) The type of responsibility demanded is exemplified by today’s climate research. (7) The paper argues for a hand-in-hand model of uncertainties in the sciences and for ethical obligations to preserve the conditions of human life on earth. The ethical argument is spelled out in terms of ethical care, preservation, and precaution. (8) Additionally, some arguments are developed to answer the question of why it is reasonable at all to preserve human life on earth.

scholarly journals Development of a Three-Dimensional Hand Model Using Three-Dimensional Stereophotogrammetry: Assessment of Image Reproducibility

PLoS ONE ◽  
2015 ◽  
Vol 10 (9) ◽  
pp. e0136710 ◽  
Author(s):  
Inge A. Hoevenaren ◽  
J. Meulstee ◽  
E. Krikken ◽  
S. J. Bergé ◽  
D. J. O. Ulrich ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Hand Model
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