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BackgroundThe photoelastic effect is used for stress measurement during endovascular surgery simulation for quantitative evaluation of catheter trajectory in in vitro environments. By extending the capabilities of this sensing technology, its potential for intravascular tools evaluation will increase.
MethodsIn this research the error introduced by stress direction on magnitude measurements was studied,...
Vascular disease is a major cause of death, therefore it is desirable to develop robots and simulation tools for catheter trajectory evaluation. Until now trajectory completion duration, catheter tip location, wall deformation, morphology and stress applied to blood vessel phantom wall were identified as evaluation parameters during endovascular surgery simulation. For that purpose image processing...
Fluid-structure interaction analysis in Internal Carotid Artery(ICA) are carried out as preparation for validation between the result of numerical simulation and photoelastic stress analysis. In this work, we assume blood vessel as an isotropic elastic medium and the wall's Poisson ratio is 0.45 and Young's modulus is 3.0Mpa. Our study shows various parameter on fluid dynamics of blood flow, such...
Silicone vasculature phantoms built relying on medical imaging data and computer assisted designed were presented in 2005 as an in-vitro simulation environment for endovascular surgery simulation. Due to the realistic recreation of human vasculature morphology and mechanical characteristics, several simulation techniques were created relying on that modeling technology to satisfy different simulation...
It is desirable for endovascular surgery simulation to describe with quantitative data the interaction between the catheter and the blood vessel model wall to make an objective evaluation of the procedure. Photoelastic stress analysis in straight segments of multi-layered models was used for that purpose. In this research we study the error introduced by stress direction on the magnitude measurements,...
The profile of rf pulses that nuclear spins experience inside a resonator deviates from that of rf voltage signals generated by a NMR spectrometer according to users’ pulse programming, when change of the profile in time is comparable to or shorter than the time constant of the resonator. In our previous work [Takeda et al., J. Magn. Reson. 197 (2009) 242–244], we proposed active compensation of rf...
To reproduce blood vessel, we proposed new process for fabricating biodegradable scaffold by powder sintering process. In this process, model for molding scaffold was materialized by rapid prototyping. Biodegradable polymer powder and porogen were dusted to model and heated. So, arbitrary shape scaffold would be fabricated. Also, porosity that influences compliance of blood vessel scaffold would be...
Technologies to develop scaffolds with controlled diameter and high porosity have great significance in tissue engineering. We have fabricated biodegradable 2D and 3D scaffolds with ordered array of pores by casting polymer on self-assembled d-fructose (sugar) microspheres. First, ferrite microparticles were encapsulated in sugar spheres to make them become magnetized. After sieving magnetic sugar...
The development of a numerical criterion to evaluate the stress on models of vasculature has applications in evaluation of human skills, robots and medical tools. This criterion will enable better medical training for endovascular surgery and the development of better medical techniques and tools. We propose to use the stress produced by human blood pressure simulation in the wall of the model of...
We proposed a fabrication method for multiscale transparent arteriole and capillary vessel models and demonstrated the fabrication of microchannels with circular cross sections ??10 - 500 ??m. First, we demonstrated fabrication of ??10 - 500 ??m arteriole and capillary vessel block models using photolithography. The circularity of fabricated ??10, 50, and 500 ??m microchannels were 84.0%, 61.5%, and...
We made transparent arteriole membranous models by using grayscale lithography. We employed a sacrificial model made of WAX and PVA mixture as a novel molding material. Our goal is to complement previous surgical simulators for practice and rehearsal of medical treatments. Since block vessel models cannot recreate moderate compliance which is similar to that of the real blood vessel, here we propose...
Artery models and surgical simulators are required for safety surgery. We have proposed a novel method to produce biological models using polyurethane elastomer, which has high photoelastic coefficient. And a method is to analyze stress on the model by circular polarized light method. the quantitative stress is analyzed from rainbow-colored photoelastic pattern. But the measurement area is restricted...
In this study, we succeeded in fine construction of the PLCL (poly-L-lactide-cocaprolactone) scaffold with micrometer range resolution using photolithography. PLCL is a biodegradable polymer which is used as a material of the scaffold to reproduce the blood vessel. Photolithography known as a technique of microfabrication was used for the processing of PLCL. By this technique, we fabricated a sheet-like...
Technologies to develop scaffolds with controlled pore layout and porosity have great significance in tissue engineering. As one method of scaffold fabrication, porogen leaching has been commonly used to control pore size, pore structure and porosity in the scaffold. In this paper, we describe a novel approach to fabricate 2D and 3D porous biodegradable scaffolds made of poly(L-lactide-co-epsiv-caprolactone)...
In this paper, we propose a method to reproduce fluoroscopic image which is utilized during endovascular surgery process, without using x-raying by introducing augmented reality technique, for constructing an endovascular simulator comprised of an in vitro patient- specific blood vessel model. To reproduce the fluoroscopic image, proposed method firstly matches the refraction index of the blood vessel...
In this work, we propose a multi-layered scaffold made of elastic biodegradable polymer PLCL [1] by salt leaching method [2], which has high porosity at inner layer and high stiffness in outer layer. Before implanting to a damaged position of a patient, scaffolds should be coated with human umbilical vein endothelial cells (HUVECs). (Porous structure is also served as a pathway of sufficient nutrients...
In this paper, we propose a novel method to develop biomimetic models using polyurethane elastomer, which has high photoelastic coefficient, and a method to analyze stress states on the model by photoelastic effect. By using this method, stress condition on vascular wall is clearly visualized on vascular fringe as rainbow-colored photoelastic pattern, and stress can be quantitatively measured from...
Technologies to develop scaffolds with controlled diameter and high porosity have great significance in tissue engineering. We have fabricated biodegradable 2D and 3D scaffolds with ordered array of pores by casting polymer on self-assembled d-fructose (sugar) microspheres. First, ferrite microparticles were encapsulated in sugar spheres to make them become magnetized. After sieving magnetic sugar...
We have been developing scaffolds of three-dimensional (3D) synthetic vascular prosthesis in tailor-made. Human umbilical vein endothelial cells (HUVECs) attached on the inner surface of the scaffold have anticoagulant effects. Asperity structures of the inner surface are important to cell adhesion. It is important to quantify the inner surface asperity condition of the scaffold by observing HUVECs...
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