Bioreactor Improvement Based on Design for Assembly in Virtual Environments

Author(s):  
Wen Li ◽  
Qingjin Peng ◽  
Malcolm Xing

A Bioreactor is a device used in tissue engineering to simulate the physiological environment required for cell growth, attachment, and immigration. The existing bioreactor is not user-friendly and difficult to operate. A great care has to be paid in the device application, such as assembly and disassembly in the operation. This research seeks to use design for assembly (DFA) methods to analyze and improve the design of the current bioreactor. Product difficulty levels are introduced to the DFA analysis. A new design is proposed to ease operation, save time and increase the application efficiency. The proposed solution is evaluated in a virtual environment using 3D assembly modeling and simulation.

Author(s):  
Rakesh Gupta ◽  
David Zeltzer

Abstract This work investigates whether estimates of ease of part handling and part insertion can be provided by multimodal simulation using virtual environment (VE) technology, rather than by using conventional table-based methods such as Boothroyd and Dewhurst Charts. To do this, a unified physically based model has been developed for modeling dynamic interactions among virtual objects and haptic interactions between the human designer and the virtual objects. This model is augmented with auditory events in a multimodal VE system called the “Virtual Environment for Design for Assembly” (VEDA). Currently these models are 2D in order to preserve interactive update rates, but we expect that these results will be generalizable to 3d models. VEDA has been used to evaluate the feasibility and advantages of using multimodal virtual environments as a design tool for manual assembly. The designer sees a visual representation of the objects and can interactively sense and manipulate virtual objects through haptic interface devices with force feedback. He/She can feel these objects and hear sounds when there are collisions among the objects. Objects can be interactively grasped and assembled with other parts of the assembly to prototype new designs and perform Design for Assembly analysis. Experiments have been conducted with human subjects to investigate whether Multimodal Virtual Environments are able to replicate experiments linking increases in assembly time with increase in task difficulty. In particular, the effect of clearance, friction, chamfers and distance of travel on handling and insertion time have been compared in real and virtual environments for peg-in-hole assembly task. In addition, the effects of degrading/removing the different modes (visual, auditory and haptic) on different phases of manual assembly have been examined.


2007 ◽  
Vol 97 (6) ◽  
pp. 1603-1616 ◽  
Author(s):  
C.A. Chung ◽  
C.W. Chen ◽  
C.P. Chen ◽  
C.S. Tseng

RSC Advances ◽  
2021 ◽  
Vol 11 (37) ◽  
pp. 22544-22555
Author(s):  
Atefeh Safaei-Yaraziz ◽  
Shiva Akbari-Birgani ◽  
Nasser Nikfarjam

The interlacing of biopolymers and synthetic polymers is a promising strategy to fabricate hydrogel-based tissue scaffolds to biomimic a natural extracellular matrix for cell growth.


2021 ◽  
Vol 11 (15) ◽  
pp. 6929
Author(s):  
Ewin Tanzli ◽  
Andrea Ehrmann

In biotechnology, the field of cell cultivation is highly relevant. Cultivated cells can be used, for example, for the development of biopharmaceuticals and in tissue engineering. Commonly, mammalian cells are grown in bioreactors, T-flasks, well plates, etc., without a specific substrate. Nanofibrous mats, however, have been reported to promote cell growth, adhesion, and proliferation. Here, we give an overview of the different attempts at cultivating mammalian cells on electrospun nanofiber mats for biotechnological and biomedical purposes. Starting with a brief overview of the different electrospinning methods, resulting in random or defined fiber orientations in the nanofiber mats, we describe the typical materials used in cell growth applications in biotechnology and tissue engineering. The influence of using different surface morphologies and polymers or polymer blends on the possible application of such nanofiber mats for tissue engineering and other biotechnological applications is discussed. Polymer blends, in particular, can often be used to reach the required combination of mechanical and biological properties, making such nanofiber mats highly suitable for tissue engineering and other biotechnological or biomedical cell growth applications.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Martin Giesel ◽  
Anna Nowakowska ◽  
Julie M. Harris ◽  
Constanze Hesse

AbstractWhen we use virtual and augmented reality (VR/AR) environments to investigate behaviour or train motor skills, we expect that the insights or skills acquired in VR/AR transfer to real-world settings. Motor behaviour is strongly influenced by perceptual uncertainty and the expected consequences of actions. VR/AR differ in both of these aspects from natural environments. Perceptual information in VR/AR is less reliable than in natural environments, and the knowledge of acting in a virtual environment might modulate our expectations of action consequences. Using mirror reflections to create a virtual environment free of perceptual artefacts, we show that hand movements in an obstacle avoidance task systematically differed between real and virtual obstacles and that these behavioural differences occurred independent of the quality of the available perceptual information. This suggests that even when perceptual correspondence between natural and virtual environments is achieved, action correspondence does not necessarily follow due to the disparity in the expected consequences of actions in the two environments.


Author(s):  
Kay M. Stanney ◽  
Kelly S. Kingdon ◽  
Robert S. Kennedy

Are current virtual environments (VEs) usable by the broad spectrum of people who may wish to utilize this technology? The current study, which examined over 1000 participants, indicates the answer to this question is a definitive ‘no’. Virtual environment exposure was found to cause people to vomit (1.1%), experience nausea (71%), disorientation (70%), and oculomotor disturbances (79%). Overall, 88% of participants reported some level of adverse symptomatology, ranging from a minor headache to vomiting and intense vertigo. These disturbances led 12% of those exposed to prematurely cease their interaction. Dropout rates as high as nearly 50% were found in exposures of 1 hr in length. In addition, long-term aftereffects were found, including headaches, drowsiness, nausea, and fatigue. These problems could substantially reduce the accessibility of VE technology by the general public and thus must be resolved if this technology is to be widely adopted.


2007 ◽  
Vol 330-332 ◽  
pp. 495-498
Author(s):  
Chao Zou ◽  
Wen Jian Weng ◽  
Xu Liang Deng ◽  
Kui Cheng ◽  
Pi Yi Du ◽  
...  

Two starting collagens, sponge and floc collagen, were used to prepare collagen/tricalcium phosphate (TCP) composites. The resulting composites were porous and had 200μm pore size. However, there was a difference in the microstructure of the pore walls for the composites derived from the two collagens, the pore walls in sponge collagen/TCP composite were still porous and had 200 nm micropores size, TCP particles were trapped in collagen matrices. While floc collagen/TCP composite had smooth and dense walls in which TCP particles were embedded. The difference could be attributed to the starting collagen with different status. Sponge collagen has a soft structure, which easily becomes disassembled fibrils during alkali treatment, the disassembled fibrils are integrated again to form a dense morphology for pore walls after freeze-drying. While floc collagen has already a low disassembly degree, the alkali treatment could not be able to separate the fibrils, this remains as micropores in pore walls after freeze-drying. Both porous composites are significant in bone tissue engineering or regeneration. MTT test results showed the two composites had good cytocompatibility, and sponge collagen/TCP composite was somewhat better than floc collagen/TCP composite, which could result from that micropores derived roughness in pore walls of sponge collagen/TCP composite is suitable for cell growth.


2012 ◽  
Vol 21 (1) ◽  
pp. 58-68 ◽  
Author(s):  
Sergio Moya ◽  
Dani Tost ◽  
Sergi Grau

We describe a graphical narrative editor that we have developed for the design of serious games for cognitive neurorehabilitation. The system is addressed to neuropsychologists. It is aimed at providing them an easy, user-friendly, and fast way of specifying the therapeutical contents of the rehabilitation tasks that constitute the serious games. The editor takes as input a description of the virtual task environment and the actions allowed inside. Therapists use it to describe the actions that they expect patients to do in order to fulfill the goals of the task and the behavior of the game if patients do not reach their goals. The output of the system is a complete description of the task logic. We have designed a 3D game platform that provides to the editor a description the 3D virtual environments, and that translates the task description created in the editor into the task logic. The main advantage of the system is that it is fully automatic, it allows therapists to interactively design the tasks and immediately validate them by realizing it virtually. We describe the design of the two applications and present the results of system testing.


1994 ◽  
Vol 3 (2) ◽  
pp. 111-129 ◽  
Author(s):  
William Bricken ◽  
Geoffrey Coco

The Virtual Environment Operating Shell (veos) was developed at University of Washington's Human Interface Technology Laboratory as software infrastructure for the lab's research in virtual environments. veos was designed from scratch to provide a comprehensive and unified management facility to support generation of, interaction with, and maintenance of virtual environments. VEOS emphasizes rapid prototyping, heterogeneous distributed computing, and portability. We discuss the design, philosophy and implementation of veos in depth. Within the Kernel, the shared database transformations are pattern-directed, communications are asynchronous, and the programmer's interface is LISP. An entity-based metaphor extends object-oriented programming to systems-oriented programming. Entities provide first-class environments and biological programming constructs such as perceive, react, and persist. The organization, structure, and programming of entities are discussed in detail. The article concludes with a description of the applications that have contributed to the iterative refinement of the VEOS software.


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