scholarly journals Comparison of Algorithms for Haptic Interaction With Isosurfaces Extracted From Volumetric Datasets

2012 ◽  
Vol 12 (2) ◽  
Author(s):  
Silvio H. Rizzi ◽  
Cristian J. Luciano ◽  
P. Pat Banerjee
Keyword(s):  
Force Feedback ◽  
Haptic Feedback ◽  
Frame Rate ◽  
Intermediate Representation ◽  
Polygonal Mesh ◽  
Tactile Interaction ◽  
Depth Buffer ◽  
3D Anatomy ◽  
Simultaneous Visualization

Combinations of graphics and haptics libraries are used in medical simulations for simultaneous visualization and tactile interaction with complex 3D anatomy models. The minimum frame rate of 1 kHz for haptics rendering makes it a nontrivial problem when dealing with complex and highly detailed polygonal models. Multiple haptics algorithms based on polygonal mesh rendering, volume haptics, and intermediate representation are evaluated in terms of their servoloop rendering time, client thread rendering time, and quality of force feedback. Algorithms include OpenHaptics’ Feedback Buffer and Depth Buffer, GodObject and Ruspini renderers in h3d, chai3d implementation in h3d, ScalarSurfaceFriction mode in Volume Haptics ToolKit (vhtk), and the authors’ intermediate representation algorithm based on volumetric data. The latter, in combination with surface graphics visualization, is found to deliver the best rendering time, to detect all collisions and to provide correct haptic feedback where other algorithms fail.

scholarly journals Influence of Force and Torque Feedback on Operator Performance in a VR-Based Suturing Task

2010 ◽  
Vol 7 (3) ◽  
pp. 217-230 ◽  
Author(s):  
L. Santos-Carreras ◽  
R. Beira ◽  
A. Sengül ◽  
R. Gassert ◽  
H. Bleuler
Keyword(s):  
Task Performance ◽  
Open Surgery ◽  
Force Feedback ◽  
Haptic Feedback ◽  
Surgical Care ◽  
Medical Background ◽  
Technological Advances ◽  
Robotic Surgical System ◽  
Surgical System

The introduction of Minimally Invasive Surgery (MIS) has revolutionised surgical care, considerably improving the quality of many surgical procedures. Technological advances, particularly in robotic surgery systems, have reduced the complexity of such an approach, paving the way for even less invasive surgical trends. However, the fact that haptic feedback has been progressively lost through this transition is an issue that to date has not been solved. Whereas traditional open surgery provides full haptic feedback, the introduction of MIS has eliminated the possibility of direct palpation and tactile exploration. Nevertheless, these procedures still provide a certain amount of force feedback through the rigid laparoscopic tool. Many of the current telemanipulated robotic surgical systems in return do not provide full haptic feedback, which to a certain extent can be explained by the requirement of force sensors integrated into the tools of the slave robot and actuators in the surgeon’s master console. In view of the increased complexity and cost, the benefit of haptic feedback is open to dispute. Nevertheless, studies have shown the importance of haptic feedback, especially when visual feedback is unreliable or absent. In order to explore the importance of haptic feedback for the surgeon’s master console of a novel teleoperated robotic surgical system, we have identified a typical surgical task where performance could potentially be improved by haptic feedback, and investigate performance with and without this feedback. Two rounds of experiments are performed with 10 subjects, six of them with a medical background. Results show that feedback conditions, including force feedback, significantly improve task performance independently of the operator’s suturing experience. There is, however, no further significant improvement when torque feedback is added. Consequently, it is deduced that force feedback in translations improves subject’s dexterity, while torque feedback might not further benefit such a task.

Effect of Frame Rate and Force Feedback on Virtual Object Manipulation

1996 ◽  
Vol 5 (1) ◽  
pp. 95-108 ◽  
Author(s):  
Paul Richard ◽  
Georges Birebent ◽  
Philippe Coiffet ◽  
Grigore Burdea ◽  
Daniel Gomez ◽  
...  
Keyword(s):  
Force Feedback ◽  
Haptic Feedback ◽  
Statistical Significance ◽  
Open Loop ◽  
Error Rates ◽  
Frame Rate ◽  
Computer Hardware ◽  
Virtual Object ◽  
Task Completion ◽  
Multimodal Feedback

Research on virtual environments (VE) produced significant advances in computer hardware (graphics boards and i/o tools) and software (real-time distributed simulations). However, fundamental questions remain about how user performance is affected by such factors as graphics refresh rate, resolution, control latencies, and multimodal feedback. This article reports on two experiments performed to examine dextrous manipulation of virtual objects. The first experiment studies the effect of graphics frame rate and viewing mode (monoscopic vs. stereoscopic) on the time required to grasp a moving target. The second experiment studies the effect of direct force feedback, pseudoforce feedback, and redundant force feedback on grasping force regulation. The trials were performed using a partially-immersive environment (graphics workstation and LCD glasses), a DataGlove, and the Rutgers Master with force feedback. Results of the first experiment indicate that stereoscopic viewing is beneficial for low refresh rates (it reduced task completion time by about 50% vs. monoscopic graphics). Results of the second experiment indicate that haptic feedback increases performance and reduces error rates, as compared to the open loop case (with no force feedback). The best performance was obtained when both direct haptic and redundant auditory feedback were provided to the user. The large number of subjects participating in these experiments (over 160 male and female) indicates good statistical significance for the above results.

Development and Testing of a Telemanipulation System With Arm and Hand Motion

2000 ◽  
Author(s):  
Michael L. Turner ◽  
Ryan P. Findley ◽  
Weston B. Griffin ◽  
Mark R. Cutkosky ◽  
Daniel H. Gomez
Keyword(s):  
Force Feedback ◽  
Haptic Feedback ◽  
Industrial Robot ◽  
Robot Hand ◽  
Robot Arm ◽  
Task Execution ◽  
Hand Motion ◽  
Instrumented Glove ◽  
Simple Manipulation ◽  
Dexterous Robot Hand

Abstract This paper describes the development of a system for dexterous telemanipulation and presents the results of tests involving simple manipulation tasks. The user wears an instrumented glove augmented with an arm-grounded haptic feedback apparatus. A linkage attached to the user’s wrist measures gross motions of the arm. The movements of the user are transferred to a two fingered dexterous robot hand mounted on the end of a 4-DOF industrial robot arm. Forces measured at the robot fingers can be transmitted back to the user via the haptic feedback apparatus. The results obtained in block-stacking and object-rolling experiments indicate that the addition of force feedback to the user did not improve the speed of task execution. In fact, in some cases the presence of incomplete force information is detrimental to performance speed compared to no force information. There are indications that the presence of force feedback did aid in task learning.

Semi-Immersive Virtual Turbine Engine Simulation System

2018 ◽  
Vol 35 (2) ◽  
pp. 149-160 ◽  
Author(s):  
Mustufa H. Abidi ◽  
Abdulrahman M. Al-Ahmari ◽  
Ali Ahmad ◽  
Saber Darmoul ◽  
Wadea Ameen
Keyword(s):  
Virtual Reality ◽  
Force Feedback ◽  
Haptic Feedback ◽  
Design System ◽  
Detection Mechanism ◽  
Turbine Engine ◽  
Surround Sound ◽  
Process Verification ◽  
Engine Simulation ◽  
Assembly Operations

AbstractThe design and verification of assembly operations is essential for planning product production operations. Recently, virtual prototyping has witnessed tremendous progress, and has reached a stage where current environments enable rich and multi-modal interaction between designers and models through stereoscopic visuals, surround sound, and haptic feedback. The benefits of building and using Virtual Reality (VR) models in assembly process verification are discussed in this paper. In this paper, we present the virtual assembly (VA) of an aircraft turbine engine. The assembly parts and sequences are explained using a virtual reality design system. The system enables stereoscopic visuals, surround sounds, and ample and intuitive interaction with developed models. A special software architecture is suggested to describe the assembly parts and assembly sequence in VR. A collision detection mechanism is employed that provides visual feedback to check the interference between components. The system is tested for virtual prototype and assembly sequencing of a turbine engine. We show that the developed system is comprehensive in terms of VR feedback mechanisms, which include visual, auditory, tactile, as well as force feedback. The system is shown to be effective and efficient for validating the design of assembly, part design, and operations planning.

Torque Control of Electrorheological Fluidic Resistive Actuators for Haptic Vehicular Instrument Controls

2005 ◽  
Vol 128 (2) ◽  
pp. 216-226 ◽  
Author(s):  
M. A. Vitrani ◽  
J. Nikitczuk ◽  
G. Morel ◽  
C. Mavroidis ◽  
B. Weinberg
Keyword(s):  
Electric Fields ◽  
Closed Loop ◽  
Force Feedback ◽  
Haptic Feedback ◽  
Control Device ◽  
Torque Control ◽  
Feedback Mechanisms ◽  
Feedforward Loop ◽  
Integral Controller ◽  
Proportional Integral Controller

Force-feedback mechanisms have been designed to simplify and enhance the human-vehicle interface. The increase in secondary controls within vehicle cockpits has created a desire for a simpler, more efficient human-vehicle interface. By consolidating various controls into a single, haptic feedback control device, information can be transmitted to the operator, without requiring the driver’s visual attention. In this paper, the experimental closed loop torque control of electro-rheological fluids (ERF) based resistive actuators for haptic applications is performed. ERFs are liquids that respond mechanically to electric fields by changing their properties, such as viscosity and shear stress electroactively. Using the electrically controlled rheological properties of ERFs, we developed resistive-actuators for haptic devices that can resist human operator forces in a controlled and tunable fashion. In this study, the ERF resistive-actuator analytical model is derived and experimentally verified and accurate closed loop torque control is experimentally achieved using a non-linear proportional integral controller with a feedforward loop.

scholarly journals Factors Affecting Spermatozoa Motility Analysis using CASA

2019 ◽  
Vol 29 (3) ◽  
pp. 145
Author(s):  
Dian Ratnawati ◽  
N Isnaini ◽  
T Susilawati
Keyword(s):  
Sample Preparation ◽  
Influencing Factors ◽  
Frame Rate ◽  
Analysis Time ◽  
Factors Affecting ◽  
Spermatozoa Motility ◽  
Fast Implementation ◽  
Concentration Chamber

Motility is a very important parameter to determine the quality of semen. Spermatozoa motility assessment can be done manually (subjectively) or with CASA. The superiority of motility assessment using CASA compared to manually is more objective, accurate, fast, efficient and able to provide detailed motility of spermatozoa. However, in implementation, assessments with CASA produce varied data. So far, there has not been a spermatozoa motility standard with CASA, except by minimizing variations in the factors that influence the results of analysis with CASA. The purpose of this paper is to describe factors that affecting spermatozoa motility analysis using CASA to reach optimal motility analysis. Some influencing factors include: CASA settings, semen diluent, spermatozoa concentration, chamber, analyst, sample preparation and analysis time. Recommendation standard motility assessments using CASA include: experienced and consistent analysts, sample preparation properly (mixing, pipeting and sampling), spermatozoa concentration of 20 million / ml, consistent in chamber type (conditioned 37°C), semen diluents and CASA settings (frame rate of 60 Hz and frame per field 30) and fast implementation of analysis (<2 minutes).

Shipboard Operations Room Layout Analysis Using Modeling and Simulation

2021 ◽  
Vol 65 (1) ◽  
pp. 1180-1184
Author(s):  
Wenbi Wang ◽  
Jimmy Le
Keyword(s):  
Spatial Layout ◽  
Face To Face ◽  
Low Profile ◽  
Room Design ◽  
Tactile Interaction ◽  
The Cost ◽  
Design Factors ◽  
Distance Interaction ◽  
Operator Interaction

The introduction of low-profile consoles into shipboard operations room opens new possibilities to design its spatial layout. A modeling study was conducted to examine six layout options by manipulating two design factors: console orientation and supervisor seat assignment. The quality of each option was evaluated algorithmically based on its support to operator interaction. The results revealed the strengths and weaknesses of each design: face-to-face was found to be superior for supporting visual and auditory communication, face-to-back was better at facilitating tactile interaction, whereas back-to-back was preferable for an operations room where extensive interaction involved operators moving to one another’s workstations. Benefits were also predicted for configurations where supervisors were assigned to a side seat, primarily for improving the cost scores of tactile and distance interaction links. Results from this study strongly support the inclusion of faceto-face setup and alternative supervisor seating assignment as options in future shipboard operations room design.

On Quality of Experience in Remote Visualization on Mobile Devices

2010 ◽  
Vol 2 (1) ◽  
pp. 1-20 ◽  
Author(s):  
Gianluca Paravati ◽  
Andrea Sanna ◽  
Fabrizio Lamberti ◽  
Luigi Ciminiera
Keyword(s):  
Mobile Devices ◽  
User Satisfaction ◽  
Network Performance ◽  
Quality Of Experience ◽  
Experimental Tests ◽  
User Preferences ◽  
Frame Rate ◽  
Remote Visualization ◽  
Server Side

Quality of Experience (QoE) is a relatively new concept which represents a way of measuring user satisfaction in the use of a certain kind of service. This work investigates issues related to the QoE in manipulating 3D scenes on mobile devices, by focusing on scenarios based on the remote visualization paradigm where a remote server is in charge of computing a flow of compressed images to be delivered to client devices. A novel approach able to dynamically set the encoding parameters at the server side is presented; the considered parameters are frame resolution, frame rate and image quality. The proposed solution is able to tune the above parameters according to both user preferences and network performance. Experimental tests are exploited to assess the relationship between the involved parameters and the QoE. Results obtained by considering low resource hardware (e.g. mobile devices) and unreliable connections (e.g. wireless networks) are presented. User feedback proves the effectiveness of the proposed approach.

scholarly journals Visual delay affects force scaling and weight perception during object lifting in virtual reality

2019 ◽  
Vol 121 (4) ◽  
pp. 1398-1409 ◽  
Author(s):  
Vonne van Polanen ◽  
Robert Tibold ◽  
Atsuo Nuruki ◽  
Marco Davare
Keyword(s):  
Virtual Reality ◽  
Multisensory Integration ◽  
Force Feedback ◽  
Haptic Feedback ◽  
Visual Signals ◽  
Visual Events ◽  
Object Lifting ◽  
Relative Weighting ◽  
The Brain ◽  
Visual Delay

Lifting an object requires precise scaling of fingertip forces based on a prediction of object weight. At object contact, a series of tactile and visual events arise that need to be rapidly processed online to fine-tune the planned motor commands for lifting the object. The brain mechanisms underlying multisensory integration serially at transient sensorimotor events, a general feature of actions requiring hand-object interactions, are not yet understood. In this study we tested the relative weighting between haptic and visual signals when they are integrated online into the motor command. We used a new virtual reality setup to desynchronize visual feedback from haptics, which allowed us to probe the relative contribution of haptics and vision in driving participants’ movements when they grasped virtual objects simulated by two force-feedback robots. We found that visual delay changed the profile of fingertip force generation and led participants to perceive objects as heavier than when lifts were performed without visual delay. We further modeled the effect of vision on motor output by manipulating the extent to which delayed visual events could bias the force profile, which allowed us to determine the specific weighting the brain assigns to haptics and vision. Our results show for the first time how visuo-haptic integration is processed at discrete sensorimotor events for controlling object-lifting dynamics and further highlight the organization of multisensory signals online for controlling action and perception. NEW & NOTEWORTHY Dexterous hand movements require rapid integration of information from different senses, in particular touch and vision, at different key time points as movement unfolds. The relative weighting between vision and haptics for object manipulation is unknown. We used object lifting in virtual reality to desynchronize visual and haptic feedback and find out their relative weightings. Our findings shed light on how rapid multisensory integration is processed over a series of discrete sensorimotor control points.

scholarly journals Smoothing Algorithm for Planar and Surface Mesh Based on Element Geometric Deformation

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Shuli Sun ◽  
Minglei Zhang ◽  
Zhihong Gou
Keyword(s):  
Weighted Average ◽  
Processing Unit ◽  
Smoothing Algorithm ◽  
Surface Mesh ◽  
Polygonal Mesh ◽  
Second Stage ◽  
Geometric Deformation ◽  
Error Metric ◽  
The Individual

Smoothing is one of the basic procedures for improvement of mesh quality. In this paper, a novel and efficient smoothing approach for planar and surface mesh based on element geometric deformation is developed. The presented approach involves two main stages. The first stage is geometric deformation of all the individual elements through a specially designed two-step stretching-shrinking operation (SSO), which is performed by moving the vertices of each element according to a certain rule in order to get better shape of the element. The second stage is to determine the position of each node of the mesh by a weighted average strategy according to quality changes of its adjacent elements. The suggested SSO-based smoothing algorithm works efficiently for triangular mesh and can be naturally expanded to quadrilateral mesh, arbitrary polygonal mesh, and mixed mesh. Combined with quadratic error metric (QEM), this approach may be also applied to improve the quality of surface mesh. The proposed method is simple to program and inherently very suitable for parallelization, especially on graphic processing unit (GPU). Results of numerical experiments demonstrate the effectiveness and potential of this method.

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