Steerability and Kinematics of Bevel-Tip Flexible Needle

2015 ◽  
Author(s):  
Dedong Gao ◽  
Yong Lei ◽  
Bin Yao ◽  
Qiang Li ◽  
Huiquan Bai
Keyword(s):  
Inverse Kinematics ◽  
Kinematic Model ◽  
Needle Insertion ◽  
The Body ◽  
Body Frame ◽  
Kinematic Equation ◽  
Solution Sets ◽  
Medical Diagnoses ◽  
Needle Deflection ◽  
Position And Orientation

Steerable flexible needles with bevel-tip are designed for many medical diagnoses and treatments. In this paper we present a new kinematic model for the bevel-tip flexible needle. Based on the analysis of needle deflection, the procedure of needle insertion can be decomposed of n sub-procedures, which are independent on the depth of insertion. In each sub-procedure, the tip is steered though the base to generate three motions with respect to the body-frame Oxiyizi: the rotation about zi, the translation along zi and the rotation about yi. The kinematics of flexible needle with bevel-tip is presented using the Denavit-Hartenberg method. The inverse kinematics of needle insertion is derived from the kinematic equation of flexible needle. The solution sets are discussed for the insertion consisting of consecutive rotation and insertion control actions. Furthermore, how to select suitable insertion position and orientation is discussed.

Mechanics-Based Interactive Modeling for Medical Flexible Needle Insertion in Consideration of Nonlinear Factors

2016 ◽  
Vol 11 (1) ◽  
Author(s):  
Shan Jiang ◽  
Xingji Wang
Keyword(s):  
Soft Tissue ◽  
Kinematic Model ◽  
Needle Insertion ◽  
Winkler Foundation ◽  
Nonlinear Characteristics ◽  
Deformation Control ◽  
Needle Deflection ◽  
Iteration Cycle ◽  
Foundation Model ◽  
Sensitivity Studies

A mechanics-based model of flexible needle insertion into soft tissue is presented in this paper. Different from the existing kinematic model, a new model has been established based on the quasi-static principle, which also incorporates the dynamics of needle motions. In order to increase the accuracy of the model, nonlinear characteristics of the flexible needle and the soft tissue are both taken into account. The nonlinear Winkler foundation model and the modified Euler–Bernoulli theory are applied in this study, providing a theoretical framework to study insertion and deformation of needles. Galerkin method and iteration cycle analysis are applied in solving a series of deformation control equations to obtain the needle deflection. The parameters used in the mechanics-based model are obtained from the needle force and needle insertion experiment. Sensitivity studies show that the model can respond reasonably to changes in response to variations in different parameters. A 50 mm needle insertion simulation and a 50 mm corresponding needle insertion experiment are conducted to prove the validity of the model. At last, a study on different needle tip bevel demonstrates that the mechanics-based model can precisely predict the needle deflection when more than one parameter is changed. The solution can also be used in optimizing trajectory of the needle tip, enabling the needle to reach the target without touching important physiological structures such as blood vessels with the help of dynamic trajectory planning.

A Model of the Human Spine: Forward and Inverse Kinematics

1992 ◽  
Author(s):  
Sunil Kumar Agrawal ◽  
Siyan Li ◽  
Glen Desmier
Keyword(s):  
Range Of Motion ◽  
Inverse Kinematics ◽  
Degrees Of Freedom ◽  
Kinematic Model ◽  
Joint Angles ◽  
Human Spine ◽  
Forward And Inverse Kinematics ◽  
Position And Orientation ◽  
Three Degrees Of Freedom ◽  
Adjacent Vertebra

Abstract The human spine is a sophisticated mechanism consisting of 24 vertebrae which are arranged in a series-chain between the pelvis and the skull. By careful articulation of these vertebrae, a human being achieves fine motion of the skull. The spine can be modeled as a series-chain with 24 rigid links, the vertebrae, where each vertebra has three degrees-of-freedom relative to an adjacent vertebra. From the studies in the literature, the vertebral geometry and the range of motion between adjacent vertebrae are well-known. The objectives of this paper are to present a kinematic model of the spine using the available data in the literature and an algorithm to compute the inter vertebral joint angles given the position and orientation of the skull. This algorithm is based on the observation that the backbone can be described analytically by a space curve which is used to find the joint solutions..

scholarly journals Aiming a Surgical Laser With an Active Cannula

2009 ◽  
Vol 3 (2) ◽  
Author(s):  
D. C. Rucker ◽  
J. M. Croom ◽  
R. J. Webster
Keyword(s):  
Inverse Kinematics ◽  
Kinematic Model ◽  
Inverse Kinematic ◽  
Outer Diameter ◽  
Laser Guidance ◽  
Wide Range ◽  
Surgical Device ◽  
Position And Orientation ◽  
Input Motion ◽  
Beam Mechanics

An active cannula is a surgical device capable of dynamically changing its curved shape in response to rotation and translation of the several precurved, concentric, superelastic tubes from which it is made. As the tubes move with respect to one another in response to input motion at their bases (outside the patient), they elastically interact, causing one another to bend. This bending can be harnessed to direct the cannula through winding trajectories within the human body. An active cannula has the potential to perform a wide range of surgical tasks, and it is especially well suited for guiding and aiming an optical fiber (e.g. BeamPath from OmniGuide, Inc.) for laser ablation. Controlling the trajectory of the laser requires control of the shape of the active cannula, and in particular the position and orientation of its tip. Prior work has shown that beam mechanics can be used to describe the shape of the cannula, given the translations and axial angles of each tube base. Here, in order to aim the laser, we invert this relationship (obtaining the “inverse kinematic”), solving for the translations and axial angles of each tube, given a desired position and orientation of the cannula tip. Experimental evaluation of inverse kinematics was carried out using a prototype consisting of three tubes. The outermost tube is straight and rigid (stainless steel), with an outer diameter (OD) of 2.4 mm. The 1.8 mm OD middle tube is superelastic Nitinol, with a preshaped circular tip. The 1.4 mm OD innermost tube is Nitinol and is not precurved, representing the straight trajectory of a laser emanating from the tip of the cannula. We assessed the accuracy of the inverse kinematics by computing the necessary tube translations and rotations needed to direct the beam of the “laser” to sequential locations along a desired trajectory consisting of two line segments that meet at a corner. These inputs were then applied at tube bases to direct the laser to thirty points along the trajectory on a flat surface 100 mm away the cannula base. The position of the tip of the simulated laser was measured using an optical tracker (Micron Tracker H3-60, Claron, Inc.). Mean error between desired and actual positions was 3.1 mm (maximum 5.5 mm). This experiment demonstrates proof of concept for laser guidance, and establishes the accuracy of the inverse kinematic model. We note that these results are applicable to guidance of a wide range of medical devices in addition to lasers. Relevant references, as well as images of our prototype and experimental data described here can be found in an online version of this abstract at http://research.vuse.vanderbilt.edu/MEDLab/. This work was supported by NSF grant #0651803, and NIH grant #1R44CA134169-01A1.

Development and analysis of a bio-inspired wire-driven variable stiffness double spring based tapered multi-section flexible robot

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Alok Ranjan Sahoo ◽  
Pavan Chakraborty
Keyword(s):  
Inverse Kinematics ◽  
Kinematic Model ◽  
Variable Stiffness ◽  
Radius Of Curvature ◽  
Flexible Robot ◽  
Content Type ◽  
Cluttered Environments ◽  
Collapsed Buildings ◽  
Practical Implications ◽  
Robot Body

Purpose The purpose of this paper is to develop a tendon actuated variable stiffness double spring based continuously tapered multi-section flexible robot and study its capability to achieve the desired bending and compression for inspection in cluttered environments. Design/methodology/approach Spring-based continuum manipulators get compressed while actuated for bending. This property can be used for the advantage in cluttered environments if one is able to control both bending and compression. Here, this paper uses a mechanics based model to achieve the desired bending and compression. Moreover, this study tries to incorporate the tapered design to help in independent actuation of the distal sections with minimal effects on proximal sections. This study is also trying to incorporate the double spring based design to minimize the number of spacers in the robot body. Findings The model was able to produce desired curvature at the tip section with less than 4.62% error. The positioning error of the manipulator is nearly 3.5% which is at par with the state-of-the-art manipulators for search and rescue operations. It was also found that the use of double spring can effectively reduce the number of spacers required. It can be helpful in smooth robot to outer world interaction without any kink. From the experiments, it has been found that the error of the kinematic model decreases as one moves from high radius of curvature to low radius of curvature. Error is maximum when the radius of curvature is infinity. Practical implications The proposed manipulator can be used for search operations in cluttered environments such as collapsed buildings and maintenance of heavy machineries in industries. Originality/value The novelty of this paper lies in the design and the proposed kinematics inverse kinematics for a spring-based continuously tapered multi-section manipulator.

scholarly journals Force-Sensor-Based Estimation of Needle Tip Deflection in Brachytherapy

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Thomas Lehmann ◽  
Mahdi Tavakoli ◽  
Nawaid Usmani ◽  
Ronald Sloboda
Keyword(s):  
Force Sensor ◽  
Needle Insertion ◽  
Interstitial Brachytherapy ◽  
Control Technique ◽  
Torque Sensor ◽  
Treatment Efficiency ◽  
Treatment Procedure ◽  
Virtual Sensor ◽  
Needle Deflection ◽  
Mechanical Models

A virtual sensor is developed for the online estimation of needle tip deflection during permanent interstitial brachytherapy needle insertion. Permanent interstitial brachytherapy is an effective, minimally invasive, and patient friendly cancer treatment procedure. The deflection of the needles used in the procedure, however, undermines the treatment efficiency and, therefore, needs to be minimized. Any feedback control technique to minimize the needle deflection will require feedback of this quantity, which is not easy to provide. The proposed virtual sensor for needle deflection incorporates a force/torque sensor, mounted at the base of the needle that always remains outside the patient. The measured forces/torques are used by a mathematical model, developed based on mechanical needle properties. The resulting estimation of tip deflection in real time during needle insertion is the main contribution of this paper. The proposed approach solely relies on the measured forces and torques without a need for any other invasive/noninvasive sensing devices. A few mechanical models have been introduced previously regarding the way the forces are composed along the needle during insertion; we will compare our model to those approaches in terms of accuracy. In order to conduct experiments to verify the deflection model, a custom-built, 2-DOF robotic system for needle insertion is developed and discussed. This system is a prototype of an intelligent, hand-held surgical assistant tool that incorporates the virtual sensor proposed in this paper.

Electric Bus Body Lightweight Design Based on Multiple Constrains

2012 ◽  
Vol 538-541 ◽  
pp. 3137-3144 ◽  
Author(s):  
Wen Wei Wang ◽  
Cheng Jun Zhou ◽  
Cheng Lin ◽  
Jiao Yang Chen
Keyword(s):  
Finite Element ◽  
Lightweight Design ◽  
Element Model ◽  
The Body ◽  
Body Frame ◽  
Electric Bus ◽  
Free Model ◽  
Bus Body ◽  
The Finite Element Model ◽  
Torsion Condition

The finite-element model of pure electric bus has been built and the free model analysis, displacement and stress analysis under bending condition and torsion condition have been conducted. Optimally design the pure electric bus frame based on multiple constrains. Reduce the body frame quality by 4.3% and meanwhile meet the modal and stress requirements.

Needle Insertion Control Method for Minimizing Both Deflection and Tissue Damage

2019 ◽  
Vol 04 (01) ◽  
pp. 1842005
Author(s):  
Ryosuke Tsumura ◽  
Yusuke Takishita ◽  
Hiroyasu Iwata
Keyword(s):  
Tissue Damage ◽  
Control Method ◽  
Axial Rotation ◽  
Needle Insertion ◽  
Experimental Results ◽  
Insertion Force ◽  
Tissue Sections ◽  
Needle Deflection ◽  
Hole Area ◽  
Insertion Method

Because fine needles can easily be deflected, accurate needle insertion is often difficult. Lower abdominal insertion is particularly difficult because of less imaging feedback; thus, an approach for allowing a straight insertion path by minimizing deflection is beneficial in cases of lower abdominal insertion. Although insertion with axial rotation can minimize deflection, the rotational insertion may cause tissue damage. Therefore, we established a novel insertion method for minimizing both deflection and tissue damage by combining rotation and vibration. Using layered tissues, we evaluated the effect of a combination of rotation and vibration in terms of deflection and tissue damage, which were measured by the insertion force and torque, and the area of the hole created by the needle using histological tissue sections to measure tissue damage. The experimental results demonstrated that insertion with unidirectional rotation is risky in terms of tissue wind-up, while insertion with bidirectional rotation can decrease deflection and avoid wind-up. We also found that insertion with vibration can decrease the insertion force and torque. Therefore, insertion with a combination of bidirectional rotation and vibration can minimize needle deflection and tissue damage, including the insertion force and torque and the hole area.

scholarly journals Three Wheeled Omnidirecional Mobile Robot - Design and Implementation

2021 ◽  
Author(s):  
Darci Luiz Tomasi Junior ◽  
Eduardo Todt
Keyword(s):  
Mobile Robot ◽  
Kinematic Model ◽  
Inverse Kinematic ◽  
Robot Design ◽  
Kinematic Equation ◽  
Design And Implementation ◽  
Validation Procedure ◽  
Functional Prototype ◽  
Detailed Presentation

This article presents a study of the resources necessary to providemovement and localization in three wheeled omnidirectionalrobots, through the detailed presentation of the mathematical proceduresapplicable in the construction of the inverse kinematic model,the presentation of the main hardware and software componentsused for the construction of a functional prototype, and the testprocedure used to validate the assembly.The results demonstrate that the developed prototype is functional,as well as the developed kinematic equation, given the smallerror presented at the end of the validation procedure.

Interlaced Attitude Estimation for Spacecraft Using Vector Observations

2021 ◽  
Vol 01 (03) ◽  
Author(s):  
Lubin Chang
Keyword(s):  
Prior Information ◽  
State Of The Art ◽  
Estimation Method ◽  
Attitude Estimation ◽  
The Body ◽  
Body Frame ◽  
Initial Value ◽  
Initial State ◽  
Initial Errors ◽  
Initial Attitude

This paper proposes an interlaced attitude estimation method for spacecraft using vector observations, which can simultaneously estimate the constant attitude at the very start and the attitude of the body frame relative to its initial state. The arbitrary initial attitude, described by constant attitude at the very start, is determined using quaternion estimator which requires no prior information. The multiplicative extended Kalman filter (EKF) is competent for estimating the attitude of the body frame relative to its initial state since the initial value of this attitude is exactly known. The simulation results show that the proposed algorithms could achieve better performance compared with the state-of-the-art algorithms even with extreme large initial errors. Meanwhile, the computational burden is also much less than that of the advanced nonlinear attitude estimators.

scholarly journals A Novel Neural Network-Based SINS/DVL Integrated Navigation Approach to Deal with DVL Malfunction for Underwater Vehicles

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Wanli Li ◽  
Mingjian Chen ◽  
Chao Zhang ◽  
Lundong Zhang ◽  
Rui Chen
Keyword(s):  
Neural Network ◽  
Autonomous Navigation ◽  
Underwater Vehicles ◽  
The Body ◽  
Doppler Velocity ◽  
Integrated Navigation ◽  
Body Frame ◽  
Short Term ◽  
The Neural Network ◽  
Nonlinear Autoregressive

A navigation grade Strapdown Inertial Navigation System (SINS) combined with a Doppler Velocity Log (DVL) is widely used for autonomous navigation of underwater vehicles. Whether the DVL is able to provide continuous velocity measurements is of crucial importance to the integrated navigation precision. Considering that the DVL may fail during the missions, a novel neural network-based SINS/DVL integrated navigation approach is proposed. The nonlinear autoregressive exogenous (NARX) neural network, which is able to provide reliable predictions, is employed. While the DVL is available, the neural network is trained by the body frame velocity and its increment from the SINS and the DVL measurements. Once the DVL fails, the well trained network is able to forecast the velocity which can be used for the subsequent navigation. From the experimental results, it is clearly shown that the neural network is able to provide reliable velocity predictions for about 200 s–300 s during DVL malfunction and hence maintain the short-term accuracy of the integrated navigation.

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