Improved Force Transmission of a Flexible Surgical Instrument by Combining Input Motion

2015 ◽  
Vol 9 (1) ◽  
Author(s):  
Jitendra P. Khatait ◽  
Dannis M. Brouwer ◽  
Ronald G. K. M. Aarts ◽  
Just L. Herder
Keyword(s):  
Friction Force ◽  
Velocity Ratio ◽  
Translational Motion ◽  
Analytical Formula ◽  
Axial Direction ◽  
Force Transmission ◽  
Multibody Model ◽  
Combined Motion ◽  
Flexible Instrument ◽  
Input Motion

The force transmission of a flexible instrument through an endoscope is considerably deteriorated due to friction between the contacting surfaces. Friction force along the axial direction can be reduced by combining the translational motion input with rotation. A ratio ζ is defined to measure the reduction in the friction force along the axial direction due to the combined motion input at the proximal end of the instrument. An analytical formula is derived that shows the reduction in the friction force for the combined motion input. A flexible multibody model was setup and various simulations were performed with different motion inputs. The simulation result showed a reduction of 80% in the value of ζ in accordance with the analytical result for the given velocity ratio. Several experiments were performed with constant translational motion input combined with constant and sinusoidal rotational motion input. A maximum reduction of 84% is obtained in the value of ζ against a reduction of 89% calculated analytically. The knowledge of force transmission with a combination of motions can be used to increase the force fidelity of a flexible instrument in applications like robotic surgery with a flexible instrument.

Effect of Combined Motion on Force Transmission of a Flexible Instrument

2014 ◽  
Author(s):  
J. P. Khatait ◽  
D. M. Brouwer ◽  
R. G. K. M. Aarts ◽  
J. L. Herder
Keyword(s):  
Friction Force ◽  
Velocity Ratio ◽  
Axial Direction ◽  
Experimental Results ◽  
Force Transmission ◽  
Rigid Tube ◽  
Combined Motion ◽  
Flexible Instrument ◽  
Translation Motion ◽  
Analytical Result

The force transmission of a flexible instrument through an endoscope is deteriorated due to friction between the contacting surfaces. Friction force along the axial direction can be reduced by combining the translation motion input with rotational motion input at the proximal end of the instrument. The effect of the combined motion on the force transmission is studied for a flexible instrument through a curved rigid tube. A mathematical formula is derived for the reduction in friction force along the axial direction due to the combined motion input. The force transmission of a flexible instrument through a curved rigid tube is analysed using the capstan equation. The ratio of the input and output forces is compared for the combined motion with that of the translation motion only. A ratio ζ is defined to measure the reduction in the friction force along the axial direction due to the combined motion input. The analytical result shows the reduction in the friction force for the combined motion input. A flexible multibody model is set up and various simulations are performed with different motion inputs. The simulation result showed a reduction in the value of ζ in accordance with the analytical result for the given velocity ratio. The results are further validated with the experimental results. The simulation and experimental results show an agreement with the analytical solutions. The knowledge of force transmission with a combination of motions can be used to increase the force fidelity of a flexible instrument in applications like robotic surgery with a flexible instrument.

Flexible Multibody Modeling of a Surgical Instrument Inside an Endoscope

2013 ◽  
Vol 9 (1) ◽  
Author(s):  
Jitendra P. Khatait ◽  
Dannis M. Brouwer ◽  
J. P. Meijaard ◽  
Ronald G. K. M. Aarts ◽  
Just L. Herder
Keyword(s):  
Surgical Instrument ◽  
Force Transmission ◽  
Positional Accuracy ◽  
Multibody Modeling ◽  
Multibody Model ◽  
Beam Elements ◽  
Spatial Beam ◽  
Flexible Multibody ◽  
Input Motion ◽  
Flexible Instruments

The implementation of flexible instruments in surgery necessitates high motion and force fidelity and good controllability of the tip. However, the positional accuracy and the force transmission of these instruments are jeopardized by the friction, the clearance, and the inherent compliance of the instrument. The surgical instrument is modeled as a series of interconnected spatial beam elements. The endoscope is modeled as a rigid curved tube. The stiffness, damping, and friction are defined in order to calculate the interaction between the instrument and the tube. The effects of various parameters on the motion and force transmission behavior were studied for the axially-loaded and no-load cases. The simulation results showed a deviation of 1.8% in the estimation of input force compared with the analytical capstan equation. The experimental results showed a deviation on the order of 1.0%. The developed flexible multibody model is able to demonstrate the characteristic behavior of the flexible instrument for both the translational and rotational input motion for a given set of parameters. The developed model will help us to study the effects of various parameters on the motion and force transmission of the instrument.

Force Analysis of the Film in a COF Chip Mounter’s Loader

2004 ◽  
Author(s):  
Dein Shaw ◽  
H. C. Lin
Keyword(s):  
Friction Force ◽  
Relative Motion ◽  
Lower Layer ◽  
Axial Direction ◽  
Tension Force ◽  
Force Distribution ◽  
Force Analysis ◽  
Transportation Vehicle

In this study, the tension force distributions in the film of COF cartridge are studied. It is noted that if the tension force on the film is too high, the interface between chip and film cracked. If the force is too low, there is no enough friction force to keep the COF in fix position when the cartridge is on the transportation vehicle. The relative motion between the chips of lower layer and the film of upper layer will cause the fatigue of interface of chips and film. It is also important to note that due to the friction the tension force at any section of the film is different. To fine the force distribution, a method to determine the tension force is developed and only effect of axial direction is considered. The assumption makes the film behave like a string. The results show that the forces on the film are different whenever the film passes a chip underneath.

Force Transfer Behavior of Mechanically Fastened Structures in Light Weight Design

2008 ◽  
Author(s):  
C. Friedrich ◽  
D. Koch ◽  
G. Dinger
Keyword(s):  
Axial Direction ◽  
Light Weight ◽  
Force Transmission ◽  
Transmission Design ◽  
Component Systems ◽  
Mechanical Fastening ◽  
Mechanically Fastened ◽  
Transfer Behavior ◽  
Weight Design ◽  
Increased Sensitivity

Light weight design gets more and more important regarding mass inertia of moved component systems. By this reason new products are using more and more light materials which exhibit an increased sensitivity due to force transmission in component contact zones. This paper gives an overview about related criteria when designing fastened component systems with transverse loading. Numeric stress analysis with FEA calculates a detailed stress distribution with significant inhomogeneities. The reasons for increased sensitivity of light materials get obvious. Often bolted joints are used to realize friction-based transverse force transmission – design criteria which become important in light weight design are shown (e.g. self loosening). Forces can also be transmitted in axial direction; an example is proposed with an effective mechanical fastening system of long composite components without adhesives. Finally, conclusions for future engineering design are drawn.

Atomistics of Friction

2005 ◽  
Author(s):  
Motohisa Hirano
Keyword(s):  
Friction Force ◽  
Translational Motion ◽  
Static Friction ◽  
System Size ◽  
Dynamic Friction ◽  
Friction Forces ◽  
Internal Motions ◽  
Locking Mechanism ◽  
Roughness Model ◽  
Solid Bodies

The atomistic mechanisms are proposed for the origin of the static and the dynamic friction forces. The mechanism for the origin of the static friction force resembles the mechanical locking mechanism in a surface roughness model. The origin of the dynamic friction force is formulated as a problem of how the given translational kinetic energy dissipates into the internal relative motions of constituent atoms of bodies during sliding. From studying that the available phase space volume of the translational motion becomes negligible small for a large system size, compared with that of the internal motions, it is concluded that the energy dissipation occurs irreversibly from the translational motion to the internal motions. A phenomenon of superlubricity, where two solid bodies move relatively with no resistance, is discussed.

scholarly journals VERIFICATION OF THE CONTROL ALGORITHM FOR RESERVOIRS WITH LIQUID BASED ON THE COMPENSATION OF THE FORCE RESPONSE IN DIFFERENT RANGES OF MANIFESTATION OF NONLINEARITIES

2020 ◽  
pp. 51-56
Author(s):  
O. Limarchenko ◽  
O. Nefedov ◽  
O. Sirenko
Keyword(s):  
Free Surface ◽  
Translational Motion ◽  
Small Dimension ◽  
System Component ◽  
Force Response ◽  
Weakly Nonlinear ◽  
Nonlinear Properties ◽  
Combined Motion ◽  
Internal Forces ◽  
Controlling Actions

Problem about motion of a reservoir with liquid with a free surface is considered based on the compensation of a force response of the liquid on reservoir walls. Such an approach is selected since usual methods of control of mechanical system motion are mostly intended for linear systems of relatively small dimension. However, models of dynamics of the combined motion of reservoirs with liquid are described with relatively high-dimensional nonlinear systems ordinary differential equations. For obtaining the mathematical model of combined motion of a reservoir with liquid with a free surface we use the Hamilton–Ostrogradskiy variational principle, for which it is possible to determine analytically all internal forces of interaction of system component parts. Namely using this algorithm, we determine the main vector of forces of the liquid pressure on reservoir walls (force response of liquid). The algorithm of the motion control of the reservoir with liquid is based on the inclusion of the compensation of the liquid force response to controlling actions, this reduces the motion of the system reservoir–liquid, where the effect of forces from oscillating liquid on the reservoir motion is eliminated. This algorithm was tested for problems of impulse and vibration disturbance of the translational motion of the system in the horizontal plain. We consider the disturbance of the system motion by a force rectangular impulse applied to the reservoir wall, the duration of the impulse is lesser than a quarter of the period of a liquid free oscillations according to the first normal mode. Amplitudes of the impulse were selected with the purpose of analysis of the behavior of the controlled system in different ranges of manifestation of nonlinearities. We state the problem to verify the accuracy of this algorithm for three ranges of manifestation of nonlinear properties in the system, namely, for the linear range (amplitudes of waves on a free surface h do not exceed 0,1 of the radius of a free surface (  <0,1R); for the weakly nonlinear range (  <0,2R) and for the strongly nonlinear range with maximum amplitudes of waves about  =0,32R. Numerical modeling enables the determination of errors of developed algorithm, which does not exceed 0,5 %, although they insignificantly increase with the increase of amplitudes of oscillations on a free surface of liquid. At the same time perturbations on a free surface of liquid for the controlled motion are always greater than for the uncontrolled motion.

3-D Multibody Modeling of a Flexible Surgical Instrument Inside an Endoscope

2012 ◽  
Author(s):  
J. P. Khatait ◽  
D. M. Brouwer ◽  
J. P. Meijaard ◽  
R. G. K. M. Aarts ◽  
J. L. Herder
Keyword(s):  
Interaction Force ◽  
Tangential Direction ◽  
Rotational Behavior ◽  
Surgical Instrument ◽  
Force Transmission ◽  
Multibody Model ◽  
Wall Stiffness ◽  
Set Up ◽  
D Model ◽  
Flexible Instruments

Modern surgical procedures involve flexible instruments for both diagnostic and therapeutic purposes. The implementation of flexible instruments in surgery necessitates high motion and force fidelity, and good controllability of the tip. However, the positional accuracy and the force transmission of these instruments are jeopardized by the friction and clearance inside the endoscope, and the compliance of the instrument. The objective of this paper is to set up a 3-D flexible multibody model for a surgical instrument inside an endoscope to study its translational and rotational behavior. The 3-D model incorporates all the deformations—axial, torsion, and bending—due to its interaction with the surroundings. The interaction due to the contact is defined along the normal and tangential direction at the contact point. The wall stiffness and damping are defined in the normal direction. Friction is defined along the tangential direction. The calculation of the interaction force and moment is explained with an example. Various simulations were performed to study the behavior of the instrument inside a curved rigid tube. The simulations for the insertion into a 3-D tube defined in a plane were compared for both 2-D and 3-D model. The simulation results from the 3-D model give the same results as the 2-D model. A simulation was carried out for the insertion in a 3-D tube using the 3-D model and the total interaction force on the instrument was analyzed. A 3-D multibody model was set up for the simulation offline rotation. A motion hysteresis of 5° was observed for the chosen configuration. The 3-D multibody model is able to demonstrate the characteristic behavior of the flexible instrument under different scenarios. Both translational and rotational behavior of the instrument can be characterized for the given set of parameters. The developed model will help us to study the effect of various parameters on the motion and force transmission of the instrument.

Design of an Experimental Set-Up to Study the Behavior of a Flexible Surgical Instrument Inside an Endoscope

2013 ◽  
Vol 7 (3) ◽  
Author(s):  
Jitendra P. Khatait ◽  
Dannis M. Brouwer ◽  
Herman M. J. R. Soemers ◽  
Ronald G. K. M. Aarts ◽  
Just L. Herder
Keyword(s):  
Modular Design ◽  
Interaction Force ◽  
Surgical Instrument ◽  
Force Transmission ◽  
Multibody Model ◽  
Displacement Sensors ◽  
Flexible Multibody ◽  
Cell Modules ◽  
Set Up

The success of flexible instruments in surgery requires high motion and force fidelity and controllability of the tip. However, the friction and the limited stiffness of such instruments limit the motion and force transmission of the instrument. In a previous study, we developed a flexible multibody model of a surgical instrument inside an endoscope in order to study the effect of the friction, bending and rotational stiffness of the instrument and clearance on the motion hysteresis and the force transmission. In this paper, we present the design and evaluation of an experimental setup for the validation of the flexible multibody model and the characterization of the instruments. A modular design was conceived based on three key functionalities: the actuation from the proximal end, the displacement measurement of the distal end, and the measurement of the interaction force. The exactly constrained actuation module achieves independent translation and rotation of the proximal end. The axial displacement and the rotation of the distal end are measured contactless via a specifically designed air bearing guided cam through laser displacement sensors. The errors in the static measurement are 15 μm in translation and 0.15 deg in rotation. Six 1-DOF load cell modules using flexures measure the interaction forces and moments with an error of 0.8% and 2.5%, respectively. The achieved specifications allow for the measurement of the characteristic behavior of the instrument inside a curved rigid tube and the validation of the flexible multibody model.

SOLID FRICTION: SPINNING AT THE ONSET OF SLIDING

2007 ◽  
Vol 21 (23n24) ◽  
pp. 4158-4163 ◽  
Author(s):  
DIETRICH E. WOLF ◽  
SILVIO R. DAHMEN ◽  
HAYE HINRICHSEN
Keyword(s):  
Friction Force ◽  
Rotational Symmetry ◽  
Translational Motion ◽  
Coarse Grained ◽  
Dynamic Friction ◽  
Interface Elements ◽  
Rigid Objects ◽  
Solid Friction ◽  
The Difference

The majority of experimental and theoretical friction studies considers translational motion, where all coarse-grained interface elements are displaced alike. An additional rotation of the slider introduces a well controlled displacement inhomogeneity across the interface. The friction response now consists of a force and a torque that are generally coupled. Recent results for a cylindrical slider are reviewed and applied to rigid objects with rotational symmetry about an axis. It is predicted that the difference between static and dynamic friction force can be suppressed, if a certain torque is applied. Moreover, we study the dynamics of the transition from sticking to sliding.

scholarly journals Study of the influence of the oncoming flow of soil on the screw surface of a subsoiler

2020 ◽  
Vol 17 ◽  
pp. 00118
Author(s):  
Ilshat Mukhametshin ◽  
Ayrat Valiev ◽  
Alexey Aleshkin ◽  
Ravil Ibyatov ◽  
Farzutdin Muhamadyarov
Keyword(s):  
Friction Force ◽  
Sliding Friction ◽  
Translational Motion ◽  
Significant Proportion ◽  
External Action ◽  
Design Parameters ◽  
Screw Surface ◽  
Tangential Forces ◽  
Optimal Values ◽  
Soil Flow

Establishing optimal technological and design parameters of tillage tools is essential for ensuring tillage quality and lowest possible energy consumption by the tillage process. For simple plane soil looseners, used on the majority of tillage machines, this task is successfully achieved. In the meanwhile, significant proportion of tillage machines has relatively complex tools, which combine translational motion of the tool with rotation around its axis. This article studies the process of soil interaction with a screw conical subsoiler mounted on bearings. The subsoiler can freely rotate around its axis. The surface of the subsoiler is described by the screw surface equation bounded by a circular cone. External action on the subsoiler body is a resultant of normal and tangential forces applied to screw surface and friction force in the bearings. Theoretical dependencies have been obtained which determine the resultant force of soil on the screw surface of the subsoiler. This force is composed of the sliding friction force and the force appearing due to frontal soil flow after destruction of soil structural cohesion. The article also gives results of numerical calculations. The obtained dependencies allow studying the influence of technological and design parameters of the screw tool on the tillage process and substantiate parameters’ optimal values.

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