Foldable Surgical Stereo Microendoscope With Continuously Adjustable Convergence

2012 ◽  
Vol 6 (1) ◽  
Author(s):  
Matteo Zoppi ◽  
Paolo Trifiletti ◽  
Rezia Molfino
Keyword(s):  
Minimally Invasive Surgery ◽  
Minimally Invasive ◽  
Invasive Surgery ◽  
Compliant Mechanism ◽  
Outer Diameter ◽  
Single Camera ◽  
Convergence Angle ◽  
Optical Axes

The paper presents a new design of a stereo endoscope for minimally invasive surgery with: cameras positioned at the tip of the instrument (inside the patient), angle of convergence of the optical axes of the cameras variable continuously, and a foldable mechanism reducing the outer diameter of the endoscope to almost the diameter of the single camera in order to reduce the size of the insertion port. After the insertion the endoscope is deployed and the two cameras move side by side. A very simple compliant mechanism is used to drive the deployment and the adjustment of the convergence angle.

Size and Shape Optimization of a 1.0mm Multifunctional Forceps-Scissors Instrument for Minimally Invasive Surgery

2007 ◽  
Author(s):  
Milton E. Aguirre ◽  
Mary Frecker
Keyword(s):  
Minimally Invasive Surgery ◽  
Minimally Invasive ◽  
Shape Optimization ◽  
Invasive Surgery ◽  
Optimization Problems ◽  
Compliant Mechanism ◽  
Linear Deformation ◽  
Cross Sectional ◽  
Size And Shape ◽  
Grasping Forces

A size and shape optimization routine is developed and implemented on a 1 mm multifunctional instrument for minimally invasive surgery. The instrument is a compliant mechanism, without hinges, capable of both grasping and cutting. Multifunctional instruments have proven to be beneficial in the operating room because of their ability to perform multiple tasks, thereby decreasing the total number of instrument exchanges in a single procedure. In addition, with fewer exchanges the risk of inadvertent tissue trauma as well as overall surgical time and costs are reduced. The focus of the paper is to investigate the performance effects of allowing the cross-sectional area along the length of the device to vary. This is accomplished by defining various cross-sectional segments along the device in terms of parametric variables (Wi) and optimizing the dimensions to provide a sufficient forceps jaw opening while maintaining adequate cutting and grasping forces. Two optimization problems are considered. First, all parametric segments are set equal to one another permitting all cross-sections to vary uniformly and achieving size optimization. Second, each segment is defined as a separate design variable to allow segments to vary independently and thereby achieving shape optimization. Due to the device’s symmetry, one-half of the mechanism is modeled as a cantilever beam undergoing large deformation. ANSYS’ optimization module is employed using the first order method because it is capable of performing optimization considering non-linear deformation and multiple loading conditions. Finally, prototypes are fabricated using wire EDM and prototype evaluations are conducted to compare size versus shape optimization, and to validate ANSYS as the solution method.

Automatic synthesis of compliant forceps for robot-assisted minimally invasive surgery

2020 ◽  
Vol 68 (11) ◽  
pp. 922-932
Author(s):  
Yilun Sun ◽  
Lingji Xu ◽  
Dingzhi Zhang ◽  
Tim C. Lueth
Keyword(s):  
Minimally Invasive Surgery ◽  
Minimally Invasive ◽  
Invasive Surgery ◽  
Compliant Mechanism ◽  
Synthesis Method ◽  
Robot Assisted ◽  
Automatic Synthesis ◽  
Geometry Modeling ◽  
3D Printed ◽  
Monolithic Structure

AbstractDue to its monolithic structure and high dexterity, the compliant mechanism becomes an emerging solution to miniaturize surgical forceps for minimally invasive procedures. However, it is complicated and inefficient to use traditional rigid-link-based kinematic method to synthesize compliant forceps. In this paper, we present a topology-optimization-based method to automatically synthesize compliant forceps for robot-assisted minimally invasive surgery (RMIS). The basic geometry modeling tool and the automatic synthesis algorithm were both implemented in Matlab. Several synthesis examples were presented to show the performance of the proposed method. The realized forceps and a continuum manipulator have been constructed and 3D-printed, which demonstrated the application of the automatic synthesis method in RMIS.

Design of a Multifunctional Compliant Instrument for Minimally Invasive Surgery

2005 ◽  
Vol 127 (6) ◽  
pp. 990-993 ◽  
Author(s):  
Mary I. Frecker ◽  
Katherine M. Powell ◽  
Randy Haluck
Keyword(s):  
Minimally Invasive Surgery ◽  
Minimally Invasive ◽  
Invasive Surgery ◽  
Compliant Mechanism ◽  
Tissue Injury ◽  
Optimized Design ◽  
Jaw Opening ◽  
Multifunctional Device ◽  
Grasping Force ◽  
Length Width

A new multifunctional compliant instrument has been designed for use in minimally invasive surgery. The instrument combines scissors and forceps into a single multifunctional device. The main advantage of using multifunctional instruments for minimally invasive surgery is that instrument exchanges can be reduced, thus reducing procedure time and risk of inadvertent tissue injury during instrument exchanges. In this paper, the length, width, and thickness of the multifunctional compliant mechanism tool tip is optimized to maximize the jaw opening and the grasping force. The optimized design is then modeled to simulate the stresses encountered in the scissors mode. A 5.0mm diameter stainless steel prototype is fabricated using electro-discharge machining and is shown to grasp and cut successfully.

scholarly journals Inverted L-Arm Gripper Compliant Mechanism

2017 ◽  
Vol 11 (3) ◽  
Author(s):  
Jason Dearden ◽  
Clayton Grames ◽  
Brian D. Jensen ◽  
Spencer P. Magleby ◽  
Larry L. Howell
Keyword(s):  
Minimally Invasive Surgery ◽  
Minimally Invasive ◽  
Invasive Surgery ◽  
Compliant Mechanisms ◽  
Compliant Mechanism ◽  
Mechanical Advantage ◽  
Bending Stresses ◽  
Materials Used ◽  
Work First ◽  
Two Degree Of Freedom

This work exploits the advantages of compliant mechanisms (devices that achieve their motion through the deflection of flexible members) to enable the creation of small instruments for minimally invasive surgery (MIS). Using flexures to achieve motion presents challenges, three of which are considered in this work. First, compliant mechanisms generally perform inadequately in compression. Second, for a ±90deg range of motion desired for each jaw, the bending stresses in the flexures are prohibitive considering materials used in current instruments. Third, for cables attached at fixed points on the mechanism, the mechanical advantage will vary considerably during actuation. Research results are presented that address these challenges using compliant mechanism principles as demonstrated in a two-degree-of-freedom (2DoF) L-Arm gripper.

Design of a 1.0mm Multifunctional Forceps-Scissors Instrument for Minimally Invasive Surgery

2006 ◽  
Author(s):  
Milton E. Aguirre ◽  
Mary Frecker
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Minimally Invasive Surgery ◽  
Minimally Invasive ◽  
Invasive Surgery ◽  
Compliant Mechanism ◽  
Rectangular Cross Section ◽  
Geometric Constraints ◽  
Element Analysis ◽  
Performance Space

A multifunctional forceps-scissors instrument is designed for minimally invasive surgery. The device is a compliant mechanism capable of both grasping and cutting. The focus of the paper is on the design optimization and a detailed finite element analysis of the compliant mechanism. One-half of the symmetric compliant mechanism is modeled as a cantilever beam of rectangular cross-section undergoing large deformation. The optimization problem is solved graphically where all feasible designs (i.e., those that satisfy the stress and geometric constraints) are displayed on performance space plots. Using this method it is easy to visualize the performance space and to select a suitable design; however, it is found that it is not possible to simultaneously maximize free deflection and blocked force in the forceps or scissors modes. A detailed finite element analysis was conducted using ANSYS to model the multiple loading conditions. A prototype instrument, fabricated from stainless steel using wire EDM with the precision of +/- 2 μm, has been tested for comparison of actual and predicted results.

scholarly journals Design of a Flexible Wasp-Inspired Tissue Transport Mechanism

2021 ◽  
Vol 9 ◽  
Author(s):  
Esther P. de Kater ◽  
Aimée Sakes ◽  
Jette Bloemberg ◽  
David J. Jager ◽  
Paul Breedveld
Keyword(s):  
Minimally Invasive Surgery ◽  
Minimally Invasive ◽  
Invasive Surgery ◽  
Transport Mechanism ◽  
Rotational Velocity ◽  
Rotation Velocity ◽  
Transport Rate ◽  
Outer Diameter ◽  
Vertical Orientation ◽  
Tissue Phantoms

Tissue transport is a challenge during Minimally Invasive Surgery (MIS) with the current suction-based instruments as the increasing length and miniaturisation of the outer diameter requires a higher pressure. Inspired by the wasp ovipositor, a slender and bendable organ through which eggs can be transported, a flexible transport mechanism for tissue was developed that does not require a pressure gradient. The flexible shaft of the mechanism consists of ring magnets and cables that can translate in a similar manner as the valves in the wasp ovipositor. The designed transport mechanism was able to transport 10wt% gelatine tissue phantoms with the shaft in straight and curved positions and in vertical orientation against gravity. The transport rate can be increased by increasing the rotational velocity of the cam. A rotational velocity of 25 RPM resulted in a transport rate of 0.8 mm/s and increasing the rotation velocity of the cam to 80 RPM increased the transport rate to 2.3 mm/s though the stroke efficiency decreased by increasing the rotational velocity of the cam. The transport performance of the flexible transport mechanism is promising. This means of transportation could in the future be an alternative for tissue transport during MIS.

Kinematic Representations of Pop-Up Paper Mechanisms

2007 ◽  
Author(s):  
Brian G. Winder ◽  
Spencer P. Magleby ◽  
Larry L. Howell
Keyword(s):  
Minimally Invasive Surgery ◽  
Minimally Invasive ◽  
Invasive Surgery ◽  
Compliant Mechanism ◽  
Deployable Structures ◽  
Kinematic Chains ◽  
Paper Folding ◽  
The Creation ◽  
Complex Mechanisms ◽  
Double Slit

Pop-up paper mechanisms use techniques very similar to the well-studied paper folding techniques of origami. However, popups differ in both the manner of construction and the target uses, warranting further study. This paper outlines the use of planar and spherical kinematics to model commonly used pop-up paper mechanisms. A survey of common joint types is given, including folds, interlocking slots, bends, pivots, sliders and rotating sliders. Also included is an overview of common onepiece and layered mechanisms, including single-slit, double-slit, V-fold, tent, tube strap and arch mechanisms. Each mechanism or joint is described using a kinematic or compliant mechanism representation. In addition, it is shown that more complex mechanisms may be created by combining simple mechanisms in various ways. The principles presented are applied to the creation of new pop-up joints and mechanisms. The new mechanisms employ both spherical and spatial kinematic chains. Various other applications are also mentioned which could benefit from the use of pop-up mechanism principles. Possible applications include deployable structures, packaging and instruments for minimally invasive surgery.

V1695: Minimizing Minimally Invasive Surgery: the Three Port Robotic Pyeloplasty

2004 ◽  
Vol 171 (4S) ◽  
pp. 448-448
Author(s):  
Farjaad M. Siddiq ◽  
Patrick Villicana ◽  
Raymond J. Leveillee
Keyword(s):  
Minimally Invasive Surgery ◽  
Minimally Invasive ◽  
Invasive Surgery ◽  
Robotic Pyeloplasty
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