scholarly journals 3-D simulation of posterior fossa reduction in Chiari I

2016 ◽  
Vol 74 (5) ◽  
pp. 405-408 ◽  
Author(s):  
Yvens Barbosa Fernandes ◽  
Pedro Fábio Mendonça Perestrelo ◽  
Pedro Yoshito Noritomi ◽  
Roger Neves Mathias ◽  
Jorge Vicente Lopes da Silva ◽  
...  

ABSTRACT We proposed a 3D model to evaluate the role of platybasia and clivus length in the development of Chiari I (CI). Using a computer aided design software, two DICOM files of a normal CT scan and MR were used to simulate different clivus lengths (CL) and also different basal angles (BA). The final posterior fossa volume (PFV) was obtained for each variation and the percentage of the volumetric change was acquired with the same method. The initial normal values of CL and BA were 35.65 mm and 112.66º respectively, with a total PFV of 209 ml. Ranging the CL from 34.65 to 29.65 – 24.65 – 19.65, there was a PFV decrease of 0.47% – 1.12% – 1.69%, respectively. Ranging the BA from 122.66º to 127.66º – 142.66º, the PFV decreased 0.69% – 3.23%, respectively. Our model highlights the importance of the basal angle and clivus length to the development of CI.

2016 ◽  
Vol 823 ◽  
pp. 396-401
Author(s):  
Adrian Cuzmoş ◽  
Dorian Nedelcu ◽  
Constantin Viorel Câmpian ◽  
Cristian Fănică ◽  
Ana Maria Budai

The paper presents a method developed and used by the CCHAPT researchers for the graphic plotting of the index tests results for hydraulic turbines, the comparison of the efficiency curves resulted from testing to those obtained by the model transposition [1] i.e. the determination and comparison of the existing combinatory cam with that obtained from tests.The method presented in the paper was born from the need for processing and presenting the results of index tests within the shortest delay and eliminating the errors that might occur in the results plotting.


PLoS ONE ◽  
2019 ◽  
Vol 14 (12) ◽  
pp. e0226322
Author(s):  
Nelson Massanobu Sakaguti ◽  
Mário Marques Fernandes ◽  
Luiz Eugênio Nigro Mazzilli ◽  
Juan Antonio Cobo Plana ◽  
Fernanda Capurucho Horta Bouchardet ◽  
...  

2002 ◽  
Vol 26 (10) ◽  
pp. 1329-1334 ◽  
Author(s):  
Borislav Kovačević ◽  
Zvonimir B. Maksić ◽  
Robert Vianello ◽  
Miljenko Primorac

2005 ◽  
Vol 127 (12) ◽  
pp. 32-34
Author(s):  
Jean Thilmany

This article discusses that how mechanical engineers will pair their already-familiar computer-aided design software with not-so-familiar three-dimensional (3D) displays for true 3D design. This is in accordance to a number of vendors' intent on supplying the newfangled computer monitors, within the next two decades. Although some of the devices are already on the market, affordable 3D monitors and displays seem to be more than a decade away, according to one university professor at work on such a project. Widespread adoption is still hindered by factors such as cost, software availability, and lack of a mouse-like device needed to interact with what’s on screen. Over the past 25 years, mechanical engineers have witnessed evolutionary change in design methods-from pen and paper to two-dimensional software and now to 3-D computer-aided design. While software makers have stepped up with sleeker and faster modeling capabilities, visualization lags. Computer users two decades out will carry out all business, web surfing, and gaming on 3-D displays. That next generation may well find the very idea of 2-D monitors to be as dated as record albums seem to teenagers today.


2014 ◽  
Vol 1036 ◽  
pp. 662-667
Author(s):  
Iulian Stǎnǎşel ◽  
Florin Blaga ◽  
Traian Buidoş

Geneva mechanism is used as a mechanism for transforming rotary motion into intermittent motion and is able to achieve a precise movement and its lock, which makes it usable in many areas, particularly in timer devices, measurement devices, feed mechanisms, positioning mechanisms, pick-up and transport machinery, textile machinery etc. The studied literature showed that, although it has long been known, this mechanism is still interesting for contemporary researchers. The present paper proposes a method of synthesis and a computer-aided kinematic and dynamic analysis for this mechanism. Based on input data, it was developed a computer program that computes the dimensions of components of Geneva mechanism and determines velocity acceleration and displacement of Geneva wheel. The dimensional calculated data were also used to obtain 3D model of the mechanism.


Author(s):  
Sean Peel ◽  
Dominic Eggbeer ◽  
Hanna Burton ◽  
Hayley Hanson ◽  
Peter L Evans

This article compared the accuracy of producing patient-specific cranioplasty implants using four different approaches. Benchmark geometry was designed to represent a cranium and a defect added simulating a craniectomy. An ‘ideal’ contour reconstruction was calculated and compared against reconstructions resulting from the four approaches –‘conventional’, ‘semi-digital’, ‘digital – non-automated’ and ‘digital – semi-automated’. The ‘conventional’ approach relied on hand carving a reconstruction, turning this into a press tool, and pressing titanium sheet. This approach is common in the UK National Health Service. The ‘semi-digital’ approach removed the hand-carving element. Both of the ‘digital’ approaches utilised additive manufacturing to produce the end-use implant. The geometries were designed using a non-specialised computer-aided design software and a semi-automated cranioplasty implant-specific computer-aided design software. It was found that all plates were clinically acceptable and that the digitally designed and additive manufacturing plates were as accurate as the conventional implants. There were no significant differences between the additive manufacturing plates designed using non-specialised computer-aided design software and those designed using the semi-automated tool. The semi-automated software and additive manufacturing production process were capable of producing cranioplasty implants of similar accuracy to multi-purpose software and additive manufacturing, and both were more accurate than handmade implants. The difference was not of clinical significance, demonstrating that the accuracy of additive manufacturing cranioplasty implants meets current best practice.


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