A miniature steerable end-effector for application in an integrated system for computer-assisted arthroscopy

2002 ◽  
Author(s):  
P. Dario ◽  
C. Paggetti ◽  
N. Troisfontaine ◽  
E. Papa ◽  
T. Ciucci ◽  
...  
Keyword(s):  
Integrated System ◽  
Computer Assisted ◽  
End Effector

Fuzzy Logic Control for an Integrated System of a Micro-Manipulator with a Single Flexible Beam

2004 ◽  
Vol 10 (5) ◽  
pp. 755-776 ◽  
Author(s):  
N. G. Chalhoub ◽  
B. A. Bazzi
Keyword(s):  
Fuzzy Logic ◽  
Fuzzy Logic Controller ◽  
Angular Displacement ◽  
Digital Simulation ◽  
Linear Quadratic Regulator ◽  
Integrated System ◽  
Flexible Beam ◽  
Linear Quadratic ◽  
End Effector ◽  
Micro Manipulator

The use of lightweight robotic manipulators in advanced assembly and manufacturing applications is hindered by the end-effector positional inaccuracies induced by the structural deformations of the arm. To address this problem, a macro- and micro-manipulator system is considered herein. Three rigid and flexible motion controllers, consisting of an integral plus state feedback controller (ISFC), linear quadratic regulator with an integral action (LQI) and a fuzzy logic controller (FLC), have been implemented in this study. The performances of these controllers are compared based on achieving zero steady-state error in the rigid body angular displacement of the beam, damping out the unwanted vibrations, rendering the end-effector insensitive to the vibrations of the arm, and avoiding excessive control torque requirements. The digital simulation results demonstrate the superiority of the FLC over the ISFC and LQI in damping out the vibrations of the beam and reducing the gripper positional inaccuracies while requiring relatively smaller control torques. Furthermore, the results clearly demonstrate the robustness of the FLC to significant variations in the payload mass.

scholarly journals Reconstruction of Complex Zygomatic Bone Defects Using Mirroring Coupled with EBM Fabrication of Titanium Implant

Metals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1250 ◽  
Author(s):  
Khaja Moiduddin ◽  
Syed Hammad Mian ◽  
Usama Umer ◽  
Naveed Ahmed ◽  
Hisham Alkhalefah ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Electron Beam ◽  
Titanium Implant ◽  
Integrated System ◽  
Implant Design ◽  
Computer Assisted ◽  
Biomechanical Behavior ◽  
Aesthetic Appearance ◽  
System Methodology ◽  
Zygomatic Implant

Reconstruction of zygomatic complex defects is a surgical challenge, owing to the accurate restoration of structural symmetry as well as facial projection. Generally, there are many available techniques for zygomatic reconstruction, but they hardly achieve aesthetic and functional properties. To our knowledge, there is no such study on zygomatic titanium bone reconstruction, which involves the complete steps from patient computed tomography scan to the fabrication of titanium zygomatic implant and evaluation of implant accuracy. The objective of this study is to propose an integrated system methodology for the reconstruction of complex zygomatic bony defects using titanium comprising several steps, right from the patient scan to implant fabrication while maintaining proper aesthetic and facial symmetry. The integrated system methodology involves computer-assisted implant design based on the patient computed tomography data, the implant fitting accuracy using three-dimensional comparison techniques, finite element analysis to investigate the biomechanical behavior under loading conditions, and finally titanium fabrication of the zygomatic implant using state-of-the-art electron beam melting technology. The resulting titanium implant has a superior aesthetic appearance and preferable biocompatibility. The customized mirrored implant accurately fit on the defective area and restored the tumor region with inconsequential inconsistency. Moreover, the outcome from the two-dimensional analysis provided a good accuracy within 2 mm as established through physical prototyping. Thus, the designed implant produced faultless fitting, favorable symmetry, and satisfying aesthetics. The simulation results also demonstrated the load resistant ability of the implant with max stress within 1.76 MPa. Certainly, the mirrored and electron beam melted titanium implant can be considered as the practical alternative for a bone substitute of complex zygomatic reconstruction.

A Translational-to-Rotational Continuously Variable Transmission Element for a Parallel Cobot

2000 ◽  
Author(s):  
Richard Emrich ◽  
Antony J. Hodgson
Keyword(s):  
Potential Application ◽  
Computer Assisted Surgery ◽  
Parallel Manipulators ◽  
Continuously Variable Transmission ◽  
Computer Assisted ◽  
End Effector ◽  
Passive Devices ◽  
Variable Transmission

Abstract Cobots are inherently passive devices which constrain the motions of an end-effector powered by external means (often a human user). Previous cobot designs have relied either on a wheel or a rotational continuously variable transmission (CVT) to couple joint velocities; these elements are best suited to planar or serial manipulator designs. In this paper, we describe the design of a new CVT mechanism which is well suited for parallel manipulators and outline a potential application in computer-assisted surgery.

Robotic handling and packaging of poultry products

Robotica ◽  
1990 ◽  
Vol 8 (4) ◽  
pp. 285-297 ◽  
Author(s):  
K. Khodabandehloo
Keyword(s):  
Machine Vision ◽  
Research Programme ◽  
Automatic Recognition ◽  
Robotic System ◽  
Integrated System ◽  
System Software ◽  
End Effector ◽  
Poultry Products ◽  
Industrial Use ◽  
Vision Module

SUMMARYThis paper presents the findings of a research programme leading to the development of a robotic system for packaging poultry portions. The results show that an integrated system, incorporating machine vision and robots, can be made feasible for industrial use. The elements of this system, including the end-effector, the vision module, the robot hardware and the system software are presented. Models and algorithms for automatic recognition and handling of poultry portions are discussed.

scholarly journals An objective structured biostatistics examination: a pilot study based on computer-assisted evaluation for undergraduates

2012 ◽  
Vol 9 ◽  
pp. 9
Author(s):  
Abdul Sattar Khan ◽  
Hamit Acemoglu ◽  
Zekeriya Akturk
Keyword(s):  
Undergraduate Education ◽  
Summative Assessment ◽  
Integrated System ◽  
Computer Assisted ◽  
Male And Female ◽  
Testing Method ◽  
Parallel Lines ◽  
Significant Difference ◽  
Trial Basis ◽  
To Receive

We designed and evaluated an objective structured biostatistics examination (OSBE) on a trial basis to determine whether it was feasible for formative or summative assessment. At Ataturk University, we have a seminar system for curriculum for every cohort of all five years undergraduate education. Each seminar consists of an integrated system for different subjects, every year three to six seminars that meet for six to eight weeks, and at the end of each seminar term we conduct an examination as a formative assessment. In 2010, 201 students took the OSBE, and in 2011, 211 students took the same examination at the end of a seminar that had biostatistics as one module. The examination was conducted in four groups and we examined two groups together. Each group had to complete 5 stations in each row therefore we had two parallel lines with different instructions to be followed, thus we simultaneously examined 10 students in these two parallel lines. The students were invited after the examination to receive feedback from the examiners and provide their reflections. There was a significant (P= 0.004) difference between male and female scores in the 2010 students, but no gender difference was found in 2011. The comparison among the parallel lines and among the four groups showed that two groups, A and B, did not show a significant difference (P> 0.05) in either class. Nonetheless, among the four groups, there was a significant difference in both 2010 (P= 0.001) and 2011 (P= 0.001). The inter-rater reliability coefficient was 0.60. Overall, the students were satisfied with the testing method; however, they felt some stress. The overall experience of the OSBE was useful in terms of learning, as well as for assessment.

Computer-assisted Fluoroscopic Targeting System for Pedicle Screw Insertion

Neurosurgery ◽  
2000 ◽  
Vol 47 (4) ◽  
pp. 872-878 ◽  
Author(s):  
William W. Choi ◽  
Barth A. Green ◽  
Allan D. O. Levi
Keyword(s):  
Pedicle Screw ◽  
Preclinical Study ◽  
Guidance System ◽  
Screw Placement ◽  
Computer Assisted ◽  
Pedicle Screw Placement ◽  
End Effector ◽  
Screw Insertion ◽  
Computed Tomographic ◽  
Fluoroscopic Imaging

Abstract OBJECTIVE Biplanar fluoroscopic imaging linked to a computer-driven mechanical end-effector is under development as a targeting system for spinal surgery. This technology has the potential to enhance standard intraoperative fluoroscopic information for localization of the pedicle entry point and trajectory, and it may be an effective alternative to the computed tomography-based image-guided system (IGS) in pedicle screw placement. A preclinical study to assess the accuracy and time efficiency of this system versus a conventional IGS was conducted. METHODS Pedicle screw placement was performed in six cadavers from T1 to S1 levels using the ViewPoint IGS (Picker International, Inc., Cleveland, OH) on one side versus the Fluorotactic guidance system (Z-Kat, Inc., Miami, FL) on the other side. Of 216 possible pedicles, 208 were instrumented; 8 pedicle diameters were too small or were not adequately imaged. Postinsertion, each pedicle was assessed for the presence and location of cortical perforation using computed tomographic scanning and direct visualization. RESULTS The number of successful screw placements was 89 (87.3%) of 102 for IGS and 87 (82.1%) of 106 for the Fluorotactic guidance system, respectively. The mean time to register and operate on one level using the Fluorotactic guidance system was 14:34 minutes (minutes:seconds), compared with 6:50 minutes using the IGS. The average fluoroscope time was 4.6 seconds per pedicle. CONCLUSION Our data indicate that this first-generation fluoroscopy-based targeting system can significantly assist the surgeon in pedicle screw placement. The overall accuracy is comparable to an IGS, especially in the region of T9–L5. A second-generation system with a faster end-effector and user-friendly interface should significantly reduce the operating and fluoroscope time.

scholarly journals Application of statistical simulation for avalanche-risk evaluation

2001 ◽  
Vol 32 ◽  
pp. 182-186 ◽  
Author(s):  
P. A. Chernouss ◽  
Yu. Fedorenko
Keyword(s):  
Risk Evaluation ◽  
Input Data ◽  
Risk Estimation ◽  
Probability Distributions ◽  
Statistical Simulation ◽  
Integrated System ◽  
Computer Assisted ◽  
Deterministic Models ◽  
Avalanche Dynamics ◽  
Avalanche Risk

AbstractAvalanche risk is considered as the probability of an avalanche event that could cause certain losses. A unified approach for avalanche-risk evaluation by statistical simulation is suggested. A chain of models, describing snow deposition, transformation, stability, avalanche dynamics and interaction with an obstacle, is used within such an approach. Each of the models evaluates a given situation in a deterministic manner, yielding a unique result value. Output data of each model can be the input for the next model in the chain. Uncertainty of input data is described in a probabilistic manner. Using the chain of the deterministic models and simulating the input data according to appropriate probability distributions with the Monte Carlo method, risk evaluations are obtained as the ratio of a number of certain types of outcome to the total number of tests. All kinds of information on weather, snow and avalanches can be used within this scheme. The simulation process can be started at any stage of the modelling. In this study it was started from the snow-cover stability simulation. Application of the statistical simulation in such a way gives an opportunity to reflect uncertainty of the initial data in the results obtained. The suggested scheme was used for producing a computer-assisted workplace for avalanche forecasting, “LAVINA”, which has been exploited at the Centre of Avalanche Safety of “Apatit”, Kirovsk, Russia, since the early 1990s. It is an integrated system that permits spatial and temporal estimations of snow stability and avalanche dynamics to be made. Assessments of the validity of the risk estimation made with LAVINA are presented.

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