Modeling of Looping Behavior in a Flexible Instrument Using a Bélzier Curve

2021 ◽  
Author(s):  
Shobhit Singhal ◽  
Jitendra P. Khatait
Keyword(s):  
Strain Energy ◽  
Dimensional Space ◽  
Plane Deformation ◽  
Three Dimensional ◽  
Industrial Applications ◽  
Flexible Instrument ◽  
Out Of Plane ◽  
Minimum Strain Energy ◽  
And Control ◽  
Three Dimensional Space

Abstract Flexible medical instruments undergo looping during insertion and navigation inside the human body. It makes the control of the distal end difficult and raises safety concerns. This paper proposes the minimum strain energy concept to get the deformed shape of a flexible instrument in three-dimensional space. A B\'{e}zier curve is used to define the trajectory of the deformed shape under different loading conditions and constraints. Looping behavior is studied for different end shortening conditions. The effect of end twist on looping behavior is studied. It is observed that end twist leads to early onset of out of plane deformation leading to looping. The strain energy plot gives an insight into the behavior of these instruments with respect to end shortening and twist. The strain energy plot shows the minimum value for $2\pi$ end twist. Therefore, the instrument tends to go for looping if the end twist is present. Force and torque characteristics are obtained which will lead to the design and control of these instruments. Force and torque plots show negative stiffness when the instrument is going for looping. The un-looping phenomenon is also discussed and a strategy is proposed to mitigate looping. The proposed modeling approach can be utilized to address the complex behavior of a flexible instrument in medical as well as in other industrial applications. The insight developed will help in designing and developing control for safe and reliable usage of flexible instruments in various domains.

scholarly journals TINJAUAN VISUAL PADA PERMAINAN DIGITAL INDONESIA BERJUDUL “DREADOUT”

2018 ◽  
Author(s):  
Nadya Nadya ◽  
Hadi Saputra
Keyword(s):  
User Interface ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Game Development ◽  
Visual Research ◽  
Digital Era ◽  
3D Game ◽  
Local Companies ◽  
And Control ◽  
Three Dimensional Space

<p><em>Game development is growing rapidly in this digital era. The graphic is also increasing more and more, especially in Three Dimensional space (3D). 3D game development is spreading around Indonesia. Now there are more local companies which making 3D games. Indonesia is one of the countries in Southeast Asia that have good enough game revenue to be the biggest one. One of the popular genre in Indonesia is survival horror. That’s because horror Indonesian stories is still have many unsolved mysterious things which can attract either domestic or foreign society. This study is including research about visualization such as 3D object from the environments and character designs. Furthermore, game also getting influenced with its system which is played by user, and its storytelling as well. The game’s layout (user interface) will categorized as a good one if it match with its theme and being consistent in visual and control. Good game must paying attention with all of those points. The conclusion of this research is to prove if 3D survival horror game visualization in Indonesia can be rated good enough in creative game industries.</em></p><p><em> </em></p><p><strong><em>Keywords:</em></strong></p><p><em>Game, Survival Horror, Visual Research</em></p>

Research on Mass Partition Coefficient for a Whole Car under Vertical and Lateral Road Excitations

2010 ◽  
Vol 29-32 ◽  
pp. 177-182 ◽  
Author(s):  
Long Wu
Keyword(s):  
Partition Coefficient ◽  
Physical Model ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Force Analysis ◽  
Analytical Results ◽  
Dynamical Coupling ◽  
And Control ◽  
Three Dimensional Space

Consider the imperfectness of mass partition coefficient for a whole car in automotive theories, a vehicle physical model with fourteen degree of freedoms under vertical and lateral road excitations is adopted as research background in this paper. With the help of force analysis of sprung mass in three dimensional space and investigations on vertical, lateral, pitch, roll and yaw motions, the ration relations of dynamical coupling between a whole suspension and four quarter suspensions are deduced and achieved. The analytical results obtained in this paper develop the theoretical content of mass partition coefficient. It will be utilized to analyze, test and control among different car suspensions in the fields of vibration, handling and steering systems in future.

Moire´-Holographic Technique for Three-Dimensional Stress Analysis

1970 ◽  
Vol 37 (1) ◽  
pp. 180-185 ◽  
Author(s):  
C. A. Sciammarella ◽  
G. Di Chirico ◽  
T.-Y. Chang
Keyword(s):  
Dimensional Space ◽  
Three Dimensional ◽  
Reconstruction Process ◽  
Double Beam ◽  
Out Of Plane ◽  
Hologram Interferometry ◽  
Moire Method ◽  
Diffraction Patterns ◽  
Good Agreement ◽  
Three Dimensional Space

The moire´ method is combined with hologram interferometry to obtain the three displacements of an arbitrarily deformed plane in the three-dimensional space. Double beam interference patterns are utilized. The interfering beams are obtained from the diffraction patterns of a grating printed in the analyzed plane. The in-plane and the out-of-plane displacements are measured in separate steps and yield separate patterns. The patterns are generated by double exposure and observed by a wave front reconstruction process. The experimental results included in the paper show a good agreement with theoretical results, proving the feasibility of the proposed technique.

Elastic Fields in a Polyhedral Inclusion With Uniform Eigenstrains and Related Problems

2000 ◽  
Vol 68 (3) ◽  
pp. 441-452 ◽  
Author(s):  
H. Nozaki ◽  
M. Taya
Keyword(s):  
Stress Field ◽  
Strain Energy ◽  
Dimensional Space ◽  
Spherical Inclusion ◽  
Three Dimensional ◽  
Elastic Field ◽  
Bounded Region ◽  
Symmetrical Structure ◽  
Elastic Fields ◽  
Three Dimensional Space

In this paper, the elastic field in an infinite elastic body containing a polyhedral inclusion with uniform eigenstrains is investigated. Exact solutions are obtained for the stress field in and around a fully general polyhedron, i.e., an arbitrary bounded region of three-dimensional space with a piecewise planner boundary. Numerical results are presented for the stress field and the strain energy for several major polyhedra and the effective stiffness of a composite with regular polyhedral inhomogeneities. It is found that the stresses at the center of a polyhedral inclusion with uniaxial eigenstrain do not coincide with those for a spherical inclusion (Eshelby’s solution) except for dodecahedron and icosahedron which belong to icosidodeca family, i.e., highly symmetrical structure.

Deformation Modeling of a Flexible Instrument Using a Bézier Curve

2020 ◽  
Author(s):  
Gudala Rajesh ◽  
Jitendra P. Khatait
Keyword(s):  
Strain Energy ◽  
Dimensional Space ◽  
Three Dimensional ◽  
The Body ◽  
Geometric Constraints ◽  
Bézier Curve ◽  
Bezier Curve ◽  
Loop Formation ◽  
Surgical Interventions ◽  
Flexible Instrument

Abstract Flexible instruments are extensively used in medical applications. Manipulation of these instruments is challenging and troublesome. To study the behavior of these instruments, different modeling approaches like finite element, Cosserat rod, and differential geometry have been used. In this paper, an alternate modeling approach using Bézier curve is proposed to understand large deformation in a flexible instrument. The shape is represented by a Bézier curve. The deformation includes extension, flexure, and torsion in the instrument. Strain energy and geometric constraints are formulated using Bézier control points. The shape of the deformed instrument under the given constraints is obtained by minimizing the total strain energy. Nonlinear constrained optimization is used for minimization to find the deformed shape. The proposed method is applied for large elastic deformation in three-dimensional space. Loop formation is observed and validated with the experimental results. The proposed method will help in understanding the mechanics of a flexible instrument. Looping is a common problem during colonoscopy. The developed model will help in developing strategies for a safer introduction of these instruments inside the body for performing diagnostic and surgical interventions.

scholarly journals A New Perspective on Low-Cost MEMS-Based AHRS Determination

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1383
Author(s):  
Neda Navidi ◽  
Rene Landry
Keyword(s):  
Reference System ◽  
Dimensional Space ◽  
Low Cost ◽  
Three Dimensional ◽  
Navigation Systems ◽  
Adaptive Kalman Filter ◽  
Initial Attitude ◽  
New Perspective ◽  
And Control ◽  
Three Dimensional Space

Attitude and heading reference system (AHRS) is the term used to describe a rigid body’s angular orientation in three-dimensional space. This paper describes an AHRS determination and control system developed for navigation systems by integrating gyroscopes, accelerometers, and magnetometers signals from low-cost MEMS-based sensors in a complementary adaptive Kalman filter. AHRS estimation based on the iterative Kalman filtering process is required to be initialized first. A new method for AHRS initialization is proposed to improve the accuracy of the initial attitude estimates. Attitude estimates derived from the initialization and iterative adaptive filtering processes are compared with the orientation obtained from a high-end reference system. The improvement in the accuracy of the initial orientation as significant as 45% is obtained from the proposed method as compared with other selected techniques. Additionally, the computational process is reduced by 96%.

Estimating the accuracy of geodetic controlling bridge cranes’ tracks complex method

2019 ◽  
Vol 944 (2) ◽  
pp. 15-21
Author(s):  
G.A. Shekhovtsov
Keyword(s):  
Dimensional Space ◽  
Three Dimensional ◽  
Radius Vector ◽  
Complex Method ◽  
Simple Method ◽  
Track Width ◽  
Total Station ◽  
And Control ◽  
Mean Square Errors ◽  
Three Dimensional Space

The method of using the electronic total station for a complex method of geodetic controlling tracks of bridge cranes is explained. This technique provides for the direct determining the x, y, z coordinates of the crane rails axial points in the controlled section of the track from one point of the total station. The values of x and y can calculate the track width and control the straightness of the rails, and the values of z to find the excess between the rail points in the row and span. Estimating the accuracy of such control’s results by obtaining the covariance matrix of coordinate errors is shown. It is noted that this form of accuracy representation is not clear enough, depends on the orientation of the coordinate axes and is not informative. The article proposes a simple method of assessing the accuracy of survey points in the directions oriented relative to crane tracks. This technique is based on the geometric interpreting the error of the defined points’ position using the circles of mean square errors, which can be constructed in any plane of three-dimensional space. By the radius-vector of these circles the MSE point defined can be judged in any given direction. On the example of estimating the accuracy of the track crane’s track width the iconic modeling is made, which confirmed the simplicity, reliability, accessibility and meaningfulness of the proposed methodology.

Extension of the Spatial PDI Model to Three Dimensions

1997 ◽  
Vol 84 (1) ◽  
pp. 176-178
Author(s):  
Frank O'Brien
Keyword(s):  
Population Density ◽  
Dimensional Space ◽  
Finite Lattice ◽  
Three Dimensional ◽  
Upper Bounds ◽  
Three Dimensions ◽  
Lower And Upper Bounds ◽  
Density Index ◽  
Three Dimensional Space

The author's population density index ( PDI) model is extended to three-dimensional distributions. A derived formula is presented that allows for the calculation of the lower and upper bounds of density in three-dimensional space for any finite lattice.

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