Pintavirooj, Chuchart

Preferred name

Alternative Name

Pintavirooj, C.

Pintavirooj, Chuchat

Main Affiliation

School of Engineering

chuchart.pi@kmitl.ac.th

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Experimental investigation of arbitrary-orientation cone-beam X-ray tomography
(2007-01-01)
Chanwimalueang, T.
;
Sangworasil, M.
;
Pintavirooj, C.
X-ray Computed Tomography is a technique to reconstruct an image of trans-axial slab of the object from a series of x-ray radiographs taken at a prior-known angle. Sequences of x-ray radiographs are served as two-dimensional projection data for a 3D tomography. The most popular Feldkamp Algorithm which is based on Filtered Backprojection (FBP) approaches has shown to perform well for 3D reconstruction. In the case of limited view, however, Feldkamp Algorithm suffers from star artifact. In these scenarios, an algebraic reconstruction technique such as the Simultaneous Algebraic Reconstruction Technique (SART) is engaged for reconstructing tomograms. Conventional x-ray computed tomography was implemented on a c-arm x-ray apparatus where the x-ray source and detector is capable of rotating to capture radiograph at any specific angle. The implementation of conebeam - geometry reconstruction algorithm, however, requires that the center location of the detector is accurately identified. Any slightly-missed alignment of the x-ray source or the detector could result in the error of the position of the center and hence the error in reconstructed image. Consequently, x-ray radiography tomography is normally implemented on a c-arm x-ray apparatus where the correct orientation of x-ray tube with respect to x-ray detector is achievable. The aim of this paper is to implement the x-ray tomography on a non c-arm x-ray apparatus where the x-ray source can be in any orientation with respect to x-ray detector. To determine the orientation, we take the radiograph of the reference transparent object, say the plastic box, of which the coordinate of the landmark, say the corner point, is known. The shadowgram of the box is analyzed to extract the coordinate of landmark image and to determine the orientation matrix using classical direct linear transform method (DLT). Once the orientation is known, modified conebeam tomography is performed to derived 3D reconstruction volumetric data. The experimental results demonstrated the potential of such method.
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Improved-resolution x-ray array detector applied for SART fanbeam
(2006-12-01)
Angsuwatanakul, T.
;
Chanwimalueang, T.
;
Pintavirooj, C.
;
Sangworasil, M.
;
Lertprasert, P.
In this paper, we investigate the design and construction of improved-resolution x-ray detector. Our detector is an array of photo-transistors coated with gadolinium based phosphor similar that used in the x-ray cassettes and used in advanced medical CT detector. The x-ray array detector module consists of two main part: the detector frontend and data acquisition system. The detector frontend includes preamplifying, low-pass filter. The data acquisition system is served to convert the signal in to digital form and forward it to personnel computer. The application of the detector as a CT detector shows a promising result. © 2006 IEEE.
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3D modeling from multiple projections: Parallel-beam to helical cone-beam trajectory
(2005-12-01)
Narkbuakaew, W.
;
Pintavirooj, C.
;
Withayachumnankul, W.
;
Sangworasil, M.
;
Taertulakarn, S.
Tomographic imaging is a technique for exploration of a cross-section of an inspected object without destruction. Normally, the input data, known as the projections, are gathered by repeatedly radiating coherent waveform through the object in a number of viewpoints, and receiving by an array of corresponding detector in the opposite position. In this research, as a replacement of radiographs, the series of photographs taken around the opaque object under the ambient light is completely served as the projections. The purposed technique can be adopted with various beam geometry including parallel-beam, cone-beam and spiral cone-beam geometry. From the process of tomography, the outcome is the stack of pseudo cross-sectional image. Not the internal of cross section is authentic, but the edge or contour is valid. Copyright UNION Agency - Science Press.
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Non-linear image registration using perspective invariant and thin-plate spine
(2004-12-01)
Putjarupong, P.
;
Pintavirooj, C.
;
Nantivatana, P.
;
Withayachumnankul, W.
;
Sangworasil, M.
We introduce a non-iterative geometric-based method to register an image using a novel set of geometric landmarks residing on an extracted 2D contours from the image. These landmarks are intrinsic and computed from the differential geometry of the curve. We exploit the invariant properties of maximum-curvature points that are local and robust under the affine and some perspective transformation. Geometric invariant exploits five-point coplanar invariant constructed from 5 consecutive landmarks. This invariant is preserved not only in affine map but weak perspective map as well. The alignment is achieved by establishing correspondences between the landmarks after a conformal sorting based on derived absolute invariant and undoing non-linear transformation which is a Thin-Plate Spline (TPS). The experiments have shown that the purposed methods are robust and promising even in the presence of noise. © 2004IEEE.
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A computational model of magnetic fluid flow based on Maxwell's equation and Navier-Stokes equations
(2006-01-01)
Lohakan, Meechai
;
Janchaichanakun, Pisuit
;
Boonsang, S.
;
Pintavirooj, C.
;
Sangworasil, M.
The magnetic liquids such as ferrofluids, biocompatible magnetic nanocarrier, play an important role as drug carriers in the human body. Based on Maxwell's equation and Navier-Stokes equations, a time-dependent analysis of a two-dimensional computational model of magnetic fluid flow is purposed. The FEM is applied to solve Maxwell's equation for a static magnetic field, and Navier-Stokes equations for fluid dynamics. The result of magnetic field has some influences to ferrofluid dynamic flow in blood vessel. ©2006 IEEE.
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3D modeling from multiple projections with arbitrary-posed camera
(2006-12-01)
Gimjumpa, S.
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Narkbuekaew, W.
;
Sangworasil, M.
;
Pintavirooj, C.
Tomographic imaging is a technique for exploration of a cross-section of an inspected object without destruction. In this research, the series of photographs taken around the opaque object under the ambient light is completely served as the projections- the so-called photo-graphic tomography. From the process of tomography, the outcome is the stack of pseudo cross-sectional image. Not the internal of cross section is authentic, but the edge or contour is valid. In this paper, the concept for 3D modeling using photographic tomography was extended to the case where the camera pose can be varied arbitrary. In such case, camera pose is determined using general camera modeling technique. The extracted geometric transform matrix is used to reorient reconstructed data before implementing the traditional tomographic process. The simulation result is very promising. © 2006 IEEE.
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Directional filter bank: An enhancement for fingerprint feature detection
(2006-12-01)
Tantachun, S.
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Pintavirooj, C.
;
Sangworasil, M.
;
Kitjaidure, Y.
Fingerprints is the most popular biometric modality. Fingerprint features include core, delta, ridge bifurcation, ridge ending, enclosure and short edge. In order to increase the performance of fingerprint identification system, it is essential that these directional-related features are needed to be enhanced. In this paper, we purpose the directional filter bank to enhance the fingerprint features which later used in classification step. Our 2D FIR filter is designed using a 2D frequency-transform method which is easily implemented and easily imposed a zero phase response. Our proposed technique demonstrates the promising results. © 2006 IEEE.
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EMG signal feature extraction based on Wavelet transform
(2010-07-30)
Mahaphonchaikul, K.
;
Sueaseenak, D.
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Pintavirooj, C.
;
Sangworasil, M.
;
Tungjitkusolmun, S.
In this paper, a multi-channel electromyogram acquisition system using programmable system on chip (PSOC) microcontroller was used to obtain the surface of EMG signal. Two pairs of single-channel surface electrodes were used to measure and record the EMG signal on forearm muscles. Then, different levels of Daubechies Wavelet family were performed to analyze the EMG signal. Finally, features in terms of root mean square, logarithm of root mean square, centroid of frequency, and standard deviation were used to extract the EMG signal. The experimental results show that root mean square feature extraction method exhibits better performance for extracting the EMG signal compared to the other features. In the future, our method can be utilized to control a mechanical arm in real-time processing.
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Fabrication of QCM sensor array and PDMS micro chamber for biosensor applications
(2009-10-22)
Jaruwongrungsee, K.
;
Maturos, T.
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Wong-ek, K.
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Sangworasil, M.
;
Pintavirooj, C.
In this work, an array of quartz crystal microbalance (QCM) sensors is fabricated on a single quartz crystal substrate and attached with poly(dimethylsiloxane) (PDMS) micro chamber for using in flow-injection system. The Cr/Au electrode array is deposited on both side of quartz substrate by sputtering through electroplated microshadow mask. PDMS micro chamber was fabricated by mold casting technique with SU-8 mold. Fabricated PDMS micro chamber and QCM sensor array were attached together for using in flow-injection system. In our experiment, the QCM electrodes were coated with the carboxylic poly(vinyl chloride) (PVC-COOH) and then the carboxylic group was activated with carbodiimide hydrochloride (EDC) and N-hydroxylsuccinimide (NHS) for protein binding. The scanning electron micrograph shown the trapped protein on the modified sensing layer, it confirmed that our QCM sensor and PDMS micro chamber can be used as QCM biosensor array. This new QCM sensor array provide possibility of multiple detection in small amount of sample within a single quartz crystal substrate that avoid the error signal from the different properties of each sensor in an array. ©2009 IEEE.
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3D modeling from using spiral cone-beam trajectory
(2005-01-01)
Narkbuakaew, W.
;
Withayachumnankul, W.
;
Pintavirooj, C.
;
Sangworasil, M.
Tomographic imaging is a technique for exploration of a cross-section of an inspected object without destruction. Normally, the input data, known as the projections, are gathered by repeatedly radiating coherent waveform through the object in a number of viewpoints, and receiving by an array of corresponding detector in the opposite position. In this research, as a replacement of radiographs, the series of photographs taken around the opaque object under the ambient light is completely served as the projections. The process is called photographic tomograph. In this paper, we purpose the 3D shape extraction based on using photographic tomography with spiral cone-beam trajectory. We have demonstrated that the purposed technique can rectify the problem of perspective occlusion that occurs when using cone-beam trajectory.

Pintavirooj, Chuchart

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