scholarly journals Prototype of Augmented Reality Technology for Orthodontic Bracket Positioning: An In Vivo Study

2021 ◽  
Vol 11 (5) ◽  
pp. 2315
Author(s):  
Yu-Cheng Lo ◽  
Guan-An Chen ◽  
Yin Chun Liu ◽  
Yuan-Hou Chen ◽  
Jui-Ting Hsu ◽  
...  

To improve the accuracy of bracket placement in vivo, a protocol and device were introduced, which consisted of operative procedures for accurate control, a computer-aided design, and an augmented reality–assisted bracket navigation system. The present study evaluated the accuracy of this protocol. Methods: Thirty-one incisor teeth were tested from four participators. The teeth were bonded by novice and expert orthodontists. Compared with the control group by Boone gauge and the experiment group by augmented reality-assisted bracket navigation system, our study used for brackets measurement. To evaluate the accuracy, deviations of positions for bracket placement were measured. Results: The augmented reality-assisted bracket navigation system and control group were used in the same 31 cases. The priority of bonding brackets between control group or experiment group was decided by tossing coins, and then the teeth were debonded and the other technique was used. The medium vertical (incisogingival) position deviation in the control and AR groups by the novice orthodontist was 0.90 ± 0.06 mm and 0.51 ± 0.24 mm, respectively (p < 0.05), and by the expert orthodontist was 0.40 ± 0.29 mm and 0.29 ± 0.08 mm, respectively (p < 0.05). No significant changes in the horizontal position deviation were noted regardless of the orthodontist experience or use of the augmented reality–assisted bracket navigation system. Conclusion: The augmented reality–assisted bracket navigation system increased the accuracy rate by the expert orthodontist in the incisogingival direction and helped the novice orthodontist guide the bracket position within an acceptable clinical error of approximately 0.5 mm.

2020 ◽  
pp. 155335062097800
Author(s):  
Ian A. Makey ◽  
Nitin A. Das ◽  
Samuel Jacob ◽  
Magdy M. El-Sayed Ahmed ◽  
Colleen M. Makey ◽  
...  

Background. Retained hemothorax (RH) is a common problem in cardiothoracic and trauma surgery. We aimed to determine the optimum agitation technique to enhance thrombus dissolution and drainage and to apply the technique to a porcine-retained hemothorax. Methods. Three agitation techniques were tested: flush irrigation, ultrasound, and vibration. We used the techniques in a benchtop model with tissue plasminogen activator (tPA) and pig hemothorax with tPA. We used the most promising technique vibration in a pig hemothorax without tPA. Statistics. We used 2-sample t tests for each comparison and Cohen d tests to calculate effect size (ES). Results. In the benchtop model, mean drainages in the agitation group and control group and the ES were flush irrigation, 42%, 28%, and 2.91 ( P = .10); ultrasound, 35%, 27%, and .76 ( P = .30); and vibration, 28%, 19%, and 1.14 ( P = .04). In the pig hemothorax with tPA, mean drainages and the ES of each agitation technique compared with control (58%) were flush irrigation, 80% and 1.14 ( P = .37); ultrasound, 80% and 2.11 ( P = .17); and vibration, 95% and 3.98 ( P = .06). In the pig hemothorax model without tPA, mean drainages of the vibration technique and control group were 50% and 43% (ES = .29; P = .65). Discussion. In vitro studies suggested flush irrigation had the greatest effect, whereas only vibration was significantly different vs the respective controls. In vivo with tPA, vibration showed promising but not statistically significant results. Results of in vivo experiments without tPA were negative. Conclusion. Agitation techniques, in combination with tPA, may enhance drainage of hemothorax.


Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 535
Author(s):  
Cătălin Alexandru

The article deals with the optimization of the azimuthal tracking mechanism for a photovoltaic (PV) platform, which uses linear actuators as actuation elements for both movements (diurnal and elevation). In the case of diurnal movement, where the platform’s angular field of orientation is large, a mechanism with a relatively simple structure is used for amplifying the actuator’s stroke and avoiding the risk of the system locking itself (by limiting the values of the transmission angle). The optimization study targets the mechanical device, the control device, and the bi-axial tracking program (embodied by the laws of motion in time for the platform’s diurnal and elevation angles) with the purpose of obtaining a high input of solar radiation, with a minimal energy consumption to achieve tracking. The study is carried out by using a virtual prototyping platform, which includes Computer Aided Design (CAD), Multi-Body Systems (MBS), and Design for Control (DFC) computer applications. The mechanical and control devices of the solar tracker are integrated and tested in mechatronic concept. The simulations’ results, which were performed for a set of representative days throughout the year, prove the effectiveness of the proposed design.


10.6036/9505 ◽  
2021 ◽  
Vol 96 (1) ◽  
pp. 145-149
Author(s):  
XABIER GARIKANO OSINAGA ◽  
MIKEL GARMENDIA MUJIKA ◽  
ANGEL PEREZ MANSO ◽  
ENEKO SOLABERRIETA MENDEZ

Computer-aided design competency is critical for an engineering graduate starting in the world of work. Therefore, the development of this competency must be in line with professional requirements and consider the design constraints. For example, in the case of modeling, a geometrically correct model may not be sufficient if it is unable to withstand the modifications required by design changes. Therefore, we consider that training must be based on the development of this knowledge, known as strategic knowledge, and encourage its acquisition. This article describes a CAD training proposal focused on the development of strategic knowledge. Starting from the contributions of researchers, the modeling process is broken down so that it can be reproduced in the different scenarios that may be presented at the time of modeling. In order to facilitate the acquisition of this knowledge, an active learning framework has been established and specific didactic strategies have been developed for this purpose. Finally, the results of an empirical test are presented after the implementation of this proposal in which the results show a notable improvement in the experimental group in relation to the control group. Keywords: CAD modeling, teaching-learning, strategic knowledge


2014 ◽  
Vol 614 ◽  
pp. 107-112
Author(s):  
Xiao Yu Yin ◽  
Xian Ping Xie ◽  
Zhen Li ◽  
Jian Gong Li ◽  
Ting Jun Wang ◽  
...  

Expert systems, or knowledge based systems, are programs in which the answer to a user-posed question is reached by logical or plausible inference rather than strictly by calculation, although calculation routines can form a major part of an expert system. Based on the integration of expert system technology and optimization technology, an intelligent computer aided design method for mine ventilation systems is proposed in this paper. Firstly, the structure and control algorithm of the intelligent design system are explored. Secondly, the knowledge types required for the mine ventilation expert system and the acquiring method of knowledge are discussed. Finally, the inference method of this expert system is put forward.


Author(s):  
Peyman Sadeghi ◽  
Yagoob Garedaghi ◽  
Mirhadi Khayatnouri ◽  
Hosein Hashemzade Farhang ◽  
Ramin Kaffash Elahi

Introduction: Hydatidosis is a global disease and one of the most dangerous zoonotic diseases which is found in areas where humans, dogs, and herbivores are in close contact with each other. Methods: In this study, a total of 64 rats were divided into control and case groups, and then 3000 protoscolices were injected into the peritoneal cavity. After 2 months, rats in the case group were given triclabendazole + levamisole at a dose of 6 mg + 4.41 mg/mL orally for 60 days, respectively. Then, after 6 months of infection, the rats of the control and case groups were killed by anesthesia and then an autopsy was performed and the viscera were carefully examined for hydatid cyst infection. Results: The results showed that in the control group, 3 cysts were observed in the liver, 10 in the kidney, and 88 in the lung. The mean number of hydatid cysts in this group was determined to be 33.6. In the case group, 2 cysts were observed in the liver, 6 in the kidney, and 64 in the lungs. The mean number of hydatid cysts in the viscera was 24 in the case group. Conclusions: Statistical analysis of the results obtained from the case and control groups showed that the therapeutic efficacy of triclabendazole + levamisole was 31%, which is not enough to treat cases of hydatid cyst.


2015 ◽  
Vol 764-765 ◽  
pp. 757-761 ◽  
Author(s):  
Yunn Lin Hwang ◽  
Jung Kuang Cheng ◽  
Van Thuan Truong

This paper presents simulation of multibody manufacturing systems with the support of numerical tools. The dynamic and cybernetic characteristics of driving system are discussed. Simple prototype models of robot arm and machine tool’s driving system are quickly established in Computer Aided Design (CAD) software inwhich the whole specification of material, inertia and so on are involved. The prototypes therefore are simulated in RecurDyn- a Computer Aided Engineering (CAE) software. The models are driven by controllers built in Matlab/Simulink via co-simulation. The results are suitable with theory and able to exploied for expansion of complexly effective factors. The research indicates that dynamic analysis and control could be done via numerical method instead of directly dynamic equation creation for multibody manufacturing systems.


2018 ◽  
Vol 224 ◽  
pp. 01078
Author(s):  
Nicolay V. Nosov ◽  
Andrey A. Cherepashkov

The article discusses the problems of computer aided design and technological preparation of production of complex shape parts on machines with numerical program control. An integrated technique for designing processes and control programs for CNC machines is proposed and described, using the technique of software-based referencing and modern electronic measuring tools.


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