scholarly journals Plane-Based Sampling for Ray Casting Algorithm in Sequential Medical Images

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Lili Lin ◽  
Shengyong Chen ◽  
Yan Shao ◽  
Zichun Gu
Keyword(s):  
Sampling Method ◽  
Three Dimensional ◽  
Ray Casting ◽  
The Novel ◽  
Novel Method ◽  
Fast Reconstruction ◽  
Intersection Points ◽  
Sequential Images ◽  
Ray Casting Algorithm ◽  
Conventional Algorithm

This paper proposes a plane-based sampling method to improve the traditional Ray Casting Algorithm (RCA) for the fast reconstruction of a three-dimensional biomedical model from sequential images. In the novel method, the optical properties of all sampling points depend on the intersection points when a ray travels through an equidistant parallel plan cluster of the volume dataset. The results show that the method improves the rendering speed at over three times compared with the conventional algorithm and the image quality is well guaranteed.

Micromachined Ultrasonic Print-Head for Deposition of High-Viscosity Materials

2010 ◽  
Vol 132 (3) ◽  
Author(s):  
J. Mark Meacham ◽  
Amanda O’Rourke ◽  
Yong Yang ◽  
Andrei G. Fedorov ◽  
F. Levent Degertekin ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Three Dimensional ◽  
High Viscosity ◽  
The Novel ◽  
Glycerol Water ◽  
Print Head ◽  
Cavity Resonances ◽  
Allowable Range ◽  
Novel Method ◽  
Manufacturing Techniques

The recent application of inkjet printing to fabrication of three-dimensional, multilayer and multimaterial parts has tested the limits of conventional printing-based additive manufacturing techniques. The novel method presented here, termed as additive manufacturing via microarray deposition (AMMD), expands the allowable range of physical properties of printed fluids to include important, high-viscosity production materials (e.g., polyurethane resins). AMMD relies on a piezoelectrically driven ultrasonic print-head that generates continuous streams of droplets from 45 μm orifices while operating in the 0.5–3.0 MHz frequency range. The device is composed of a bulk ceramic piezoelectric transducer for ultrasound generation, a reservoir for the material to be printed, and a silicon micromachined array of liquid horn structures, which make up the ejection nozzles. Unique to this new printing technique are the high frequency of operation, use of fluid cavity resonances to assist ejection, and acoustic wave focusing to generate the pressure gradient required to form and eject droplets. We present the initial characterization of a micromachined print-head for deposition of fluids that cannot be used with conventional printing-based rapid prototyping techniques. Glycerol-water mixtures with a range of properties (surface tensions of ∼58–73 mN/m and viscosities of 0.7–380 mN s/m2) were used as representative printing fluids for most investigations. Sustained ejection was observed in all cases. In addition, successful ejection of a urethane-based photopolymer resin (surface tension of ∼25–30 mN/m and viscosity of 900–3000 mN s/m2) was achieved in short duration bursts. Peaks in the ejection quality were found to correspond to predicted device resonances. Based on these results, we have demonstrated the printing of fluids that fall well outside of the accepted range for the previously introduced printing indicator. The micromachined ultrasonic print-head achieves sustained printing of fluids up to 380 mN s/m2, far above the typical printable range.

scholarly journals Novel Method for the Manufacture of Complex CFRP Parts Using FDM-based Molds

Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2220
Author(s):  
Paul Bere ◽  
Calin Neamtu ◽  
Razvan Udroiu
Keyword(s):  
Fused Deposition Modeling ◽  
Three Dimensional ◽  
Acrylonitrile Butadiene Styrene ◽  
The Novel ◽  
Reinforced Polymers ◽  
Fused Deposition ◽  
Molded Parts ◽  
Deposition Modeling ◽  
Composite Tooling ◽  
Novel Method

Fibre-reinforced polymers (FRP) have attracted much interest within many industrial fields where the use of 3D printed molds can provide significant cost and time savings in the production of composite tooling. Within this paper, a novel method for the manufacture of complex-shaped FRP parts has been proposed. This paper features a new design of bike saddle, which was manufactured through the use of molds created by fused deposition modeling (FDM), of which two 3D printable materials were selected, polylactic acid (PLA) and acrylonitrile butadiene styrene (ABS), and these molds were then chemically and thermally treated. The novel bike saddles were fabricated using carbon fiber-reinforced polymer (CFRP), by vacuum bag technology and oven curing, utilizing additive manufactured (AM) molds. Following manufacture the molded parts were subjected to a quality inspection, using non-contact three-dimensional (3D) scanning techniques, where the results were then statistically analyzed. The statistically analyzed results state that the main deviations between the CAD model and the manufactured CFRP parts were within the range of ±1 mm. Additionally, the weight of the upper part of the saddles was found to be 42 grams. The novel method is primarily intended to be used for customized products using CFRPs.

Measurement of the International Normalized Ratio (INR) in Hemodialysis Patients with Heparin-Locked Central venous Catheters: Evaluation of a Novel Blood Sampling Method

2009 ◽  
Vol 10 (3) ◽  
pp. 180-182 ◽  
Author(s):  
Jean-Philippe Rioux ◽  
Bruno De Bortoli ◽  
Serge Quérin ◽  
Clément Déziel ◽  
Stéphan Troyanov ◽  
...  
Keyword(s):  
Sampling Method ◽  
Sampling Technique ◽  
International Normalized Ratio ◽  
The Novel ◽  
Blood Contamination ◽  
Simple Method ◽  
Heparin Administration ◽  
Novel Method ◽  
Clinically Significant ◽  
Central Catheters

Background Accurate measurement of the international normalized ratio (INR) may be difficult in hemodialysis (HD) patients with heparin-locked central catheters. Blood contamination with locking solutions may interfere with INR measurement when samples are collected directly from the catheter. Methods The aim of our study was to evaluate a novel sampling method for the measurement of INR in HD patients with heparin-locked central catheters. This novel method consists of measuring the INR directly from the dialysis circuit (arterial bloodline sample port) after 1 hr of treatment regardless of heparin administration during dialysis. We compared this method to the gold standard (peripheral venipuncture prior to dialysis) using the paired t-test. We included 30 patients (23 with warfarin therapy and 7 without). Results INRs obtained using the novel sampling method were only minimally overestimated compared to venipuncture values (mean INR overestimation: 0.2 +/- 0.2). This overestimation was not clinically significant and did not lead to changes in warfarin prescription for any of the patients. Correlation tests confirmed the influence of heparin administration on INR overestimation (R=0.4; p=0.05). This influence was present mostly among patients receiving more than 100 Units/kg of heparin during their treatment. Conclusion This novel sampling technique provides a convenient and simple method of monitoring INR among HD patients.

A novel method for determining the X-ray beam angulation of the supraspinatus outlet view

2021 ◽  
pp. 028418512110438
Author(s):  
Xiaoli Zheng ◽  
Jingying Hu ◽  
Jian Xu ◽  
Zhen Wang ◽  
Zhenyu Shu ◽  
...  
Keyword(s):  
Success Rate ◽  
Pearson Correlation ◽  
Three Dimensional ◽  
The Novel ◽  
Ct Reconstruction ◽  
Beam Angle ◽  
X Ray ◽  
Horizontal Angle ◽  
Novel Method ◽  
First Time

Background Rapid and accurate quantification of the supraspinatus outlet view (SOV) is a clinical challenge. Purpose To quantify the X-ray beam angle of the SOV using the horizontal angle of the subscapular spine line (SSSL) and to further verify the feasibility of this method. Material and Methods A total of 119 patients who underwent shoulder computed tomography (CT) examination were enrolled in the retrospective study. Three-dimensional (3D) CT reconstruction was performed and manually adjusted to provide the position similar to SOV. The rotation angle of the 3D image along the long axis of the human body (marked as β) was obtained. The horizontal angle of SSSL (marked as α) was measured on the anteroposterior localizer image of shoulder CT. Pearson correlation and linear regression correlation analysis were performed. In addition, the first-time success rate between the experience-based group and the measurement-based group were compared to verify the novel method. Results We found a linear correlation between α and β (r = 0.962; P = 0.000). There was no significant correlation between the experience-based group and the measurement-based group in terms of age ( P = 0.500), sex ( P = 0.397), and side ( P = 0.710), but there was a significant statistical difference in the first success rate between the two validation groups (χ2 = 5.808a, P = 0.016). Conclusion This novel quantitative measurement method for determining the X-ray beam angle of SOV using the horizontal angle of SSSL is feasible.

scholarly journals Fuzzy Mutual Information-Based Intraslice Grouped Ray Casting

2019 ◽  
Vol 28 (1) ◽  
pp. 77-86 ◽  
Author(s):  
R. Mehaboobathunnisa ◽  
A.A. Haseena Thasneem ◽  
M. Mohamed Sathik
Keyword(s):  
Image Quality ◽  
Mutual Information ◽  
Three Dimensional ◽  
Ray Casting ◽  
Two Dimensional ◽  
Volume Data ◽  
Grouping Strategy ◽  
Color Data ◽  
Ray Casting Algorithm ◽  
Data Group

Abstract The traditional ray casting algorithm has the capability to render three-dimensional volume data in the viewable two-dimensional form by sampling the color data along the rays. The speed of the technique relies on the computation incurred by the huge volume of rays. The objective of the paper is to reduce the computations made over the rays by eventually reducing the number of samples being processed throughout the volume data. The proposed algorithm incorporates the grouping strategy based on fuzzy mutual information (FMI) over a group of voxels in the conventional ray casting to achieve the reduction. For the data group, with FMI in a desirable range, a single primary ray is cast into the group as a whole. As data are grouped before casting rays, the proposed algorithm reduces the interpolation calculation and thereby runs with lesser complexity, preserving the image quality.

APPLICATION OF ABRASIVE-WATER JET TECHNOLOGY FOR MATERIAL SCULPTURING

2010 ◽  
Vol 34 (3-4) ◽  
pp. 389-400 ◽  
Author(s):  
Przemyslaw J. Borkowski
Keyword(s):  
Water Pressure ◽  
Three Dimensional ◽  
Water Jet ◽  
The Novel ◽  
Abrasive Water Jet ◽  
Two Dimensional Image ◽  
Novel Approach ◽  
Novel Method ◽  
Experimental Testbed ◽  
Different Levels

This paper presents a novel method for the 3D sculpturing of different materials using a high-pressure abrasive water jet. The approach involves scanning an image, such as a photograph, and relating the color values of each pixel in the resulting bitmap image to the feed rate of the water jet. Keeping all other parameters such as stand-off distance and water pressure constant, different water jet feed rates will causes different levels of erosion of material. As a result, a three-dimensional sculptured surface will be realized from a two-dimensional image. The paper describes a mathematical model for shaping the material, as well as the experimental testbed used to test the novel approach. Also presented are methodical and experimental erosion results as well as a particular example of bas-relief made of metal.

scholarly journals Three-Dimensional Cloud Volume Reconstruction from the Multi-angle Imaging SpectroRadiometer

2018 ◽  
Vol 10 (11) ◽  
pp. 1858 ◽  
Author(s):  
Byungsuk Lee ◽  
Larry Di Girolamo ◽  
Guangyu Zhao ◽  
Yizhe Zhan
Keyword(s):  
Three Dimensional ◽  
Correction Method ◽  
Heat Fluxes ◽  
Reconstruction Method ◽  
Ray Casting ◽  
Pixel Resolution ◽  
Reconstructed Volume ◽  
Ellipsoidal Surface ◽  
Cloud Mask ◽  
Ray Casting Algorithm

Characterizing 3-D structure of clouds is needed for a more complete understanding of the Earth’s radiative and latent heat fluxes. Here we develop and explore a ray casting algorithm applied to data from the Multi-angle Imaging SpectroRadiometer (MISR) onboard the Terra satellite, in order to reconstruct 3-D cloud volumes of observed clouds. The ray casting algorithm is first applied to geometrically simple synthetic clouds to show that, under the assumption of perfect, clear-conservative cloud masks, the reconstruction method yields overestimation in the volume whose magnitude depends on the cloud geometry and the resolution of the reconstruction grid relative to the image pixel resolution. The method is then applied to two hand-picked MISR scenes, fully accounting for MISR’s viewing geometry for reconstructions over the Earth’s ellipsoidal surface. The MISR Radiometric Camera-by-camera Cloud Mask (RCCM) at 1.1-km resolution and the custom cloud mask at 275-m resolution independently derived from MISR’s red, green, and blue channels are used as input cloud masks. A wind correction method, termed cloud spreading, is applied to the cloud masks to offset potential cloud movements over short time intervals between the camera views of a scene. The MISR cloud-top height product is used as a constraint to reduce the overestimation at the cloud top. The results for the two selected scenes show that the wind correction using the cloud spreading method increases the reconstructed volume up to 4.7 times greater than without the wind correction, and that the reconstructed volume generated from the RCCM is up to 3.5 times greater than that from the higher-resolution custom cloud mask. Recommendations for improving the presented cloud volume reconstructions, as well as possible future passive remote sensing satellite missions, are discussed.

scholarly journals Research on Improved Ray Casting Algorithm and Its Application in Three-Dimensional Reconstruction

2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
ZheShu Jia ◽  
DeYun Chen ◽  
Bo Wang
Keyword(s):  
Sampling Method ◽  
Transfer Functions ◽  
Three Dimensional ◽  
Projection Algorithm ◽  
Sampling Point ◽  
Ray Casting ◽  
Weighted Interpolation ◽  
Sampling Points ◽  
Trilinear Interpolation ◽  
Ct Data

Spinal pathology treatment has become an urgent issue to be solved. How to effectively prevent and treat spinal pathology has become a research hotspot in the field of surgery. Aiming at the problem of too long volume rendering time caused by the trilinear interpolation sampling method in the reconstruction and visualization of the vertebra 3D model, an improved ray projection algorithm is proposed to quickly reconstruct a 3D vertebra model from medical CT vertebra images. This method first classifies CT data, assigns corresponding color values and opacity transfer functions to different types of data, and then uses inverse distance-weighted interpolation (IDWI) sampling to replace the trilinear interpolation sampling method for the voxel where the sampling point is located to accelerate the interpolation operation. The color value and opacity of the sampling points are obtained, and finally, the attributes of all the sampling points are synthesized and calculated to obtain the final rendering effect, and the reconstruction of the three-dimensional vertebra model is completed. Experimental results show that the proposed method not only can obtain higher quality rendered images but also has a certain improvement in rendering speed compared with traditional algorithms.

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