Pintavirooj, Chuchart

Preferred name

Alternative Name

Pintavirooj, C.

Pintavirooj, Chuchat

Main Affiliation

School of Engineering

chuchart.pi@kmitl.ac.th

Now showing 1 - 10 of 46

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Combined medical imaging with CFD analysis for application of diagnostic and treatment planning: The case study of human nasal airflow simulation based on CT imaging
(2009-01-01)
Hemtiwakorn, Khaisang
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Phoocharoen, Niwat
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Tungjitkusolmun, Supan
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Mahasittiwat, Visan
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Sangworasil, Manas
The previous methods of human airflow measurement such as rhinomanometry or acoustic rhinometry could not visualize the airflow and calculated the velocity magnitude in specific region of nasal cavity. Thus, this study proposes the combination of CT and CFD analysis of nasal airflow simulation in normal human breathing. This method can demonstrate the airflow direction, and also calculate the velocity magnitude inside the nasal cavity. The processes of this study are segmentation, meshing, solving, and post-processing. Firstly, Mimic 10.01 software was used to segment the nasal cavity. Secondly, Pro-STAR/amm software was used to generate trimmed mesh of 338, 496 elements. Finally, computational grid model was imported to STAR-CD version 3.26 for numerical computation, and visualize the solution by post-processing. The result shows that velocity magnitude of airflow is greatest in nasal valve area which is the narrowest area of the human nose. Also, the flow commonly pass through the main nasal passage and middle meatus areas of nose. Experimental validation will be reported in the further publication. In conclusion, this study is the important begining of an applied CFD analysis with medical imaging. CT imaging combines with CFD analysis could be useful for rhinologist as a nose function evaluation technique. Moreover, the applications of this method could be utilized in a wide range of research topics, especially development of diagnostic and treatment planning techniques.
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Acclerate a DLT motion capture system with quad-tree searching scheme
(2006-12-01)
Chaichana, Thanapong
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Sangworasil, Manas
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Pintavirooj, Chuchart
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Aootaphao, Sorapong
This paper describes a 3D motion capture system to generate a skeleton model representing the human body. The system consists of a number of digital cameras placed at arbitrary position around the subject. The subject's joints to be measured are attached with illuminated landmarks. The 3D dynamic information of these landmarks is then detected using the Direct Linear Transform (DLT) technique. In order to establish corresponding point of the landmarks across individual camera as required in the DLT procedure, the quad-tree searching scheme has been adopted which can speed up the dynamic 3D modelling process of up to 70 percent. The 3D motion capture system has been performed to visualize the motion of various subjects. The result is very promising © 2006 IEEE.
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Experimental investigation of arbitrary-orientation cone-beam X-ray tomography
(2007-01-01)
Chanwimalueang, T.
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Sangworasil, M.
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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.
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Chanwimalueang, T.
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Pintavirooj, C.
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Sangworasil, M.
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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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Biometrics with Eigen-hand
(2006-12-01)
Tantachun, S.
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Pintavirooj, C.
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Lertprasart, Polsart
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Bunluechokchai, S.
Biometrics such as fingerprints, hand geometry, face and voice biometrics provide a reliable alternative for identity verification and are gaining industry and citizen acceptance. Among these, hand geometry verification has emerged as the most suitable biometric modality for medium and low security application due to its speed and unobtrusive nature. However, the applications of hand geometry have been limited due to its limited accuracy when compared to other modalities. The concept of the well-known Eigen face have been applied for palmprint image for person identification. The derived Eigen value and Eigen vector contributes to the important feature in the classification process. For training the classifiers, a library set of 50 patterns is used. The tested data consists of 100 samples and produced correct classification rate close to 95% © 2006 IEEE.
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X-ray -detector with CMOS sensor camera application of calcium denisty measurement
(2006-12-01)
Pititheerapab, Y.
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Chanmalueang, T.
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Rerksngaem, T.
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Kitipol, C.
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Pintavirooj, C.
This paper presented a design of an x-ray-detector using CMOS image sensor. The main components consist of CMOS sensor, taper fiber optic, and image intensifier screen, CMOS sensor offers various advantages including miniaturesized, low power consumption and cost effective. CMOS-based digital camera becomes hence very demanding due to its potential application in multimedia and information technology. To apply the CMOS sensor as x-ray detector, x-ray-to-visible light convector is required. Our key component of x-ray-tovisible light converter is an image intensifier screen mounted on the wider end of taper fiber optic. The narrow end of the taper fiber optic is coupled on the half-inch CMOS image sensor. In order to get higher image quality and system flexibility, more versatile CMOS image-sensor controller are preferable. Such complicate designs are made possible by the creation of entirely VHDL reconfiguration and programmable components- the socalled Field programmable Gate Array (FPGA). The designed x-ray-detector with CMOS sensor camera has been tested to capture a bony structure and ap-plied for calcium measurement. The result is very promising. © 2006 IEEE.
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3D modeling from multiple projections: Parallel-beam to helical cone-beam trajectory
(2005-12-01)
Narkbuakaew, W.
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Pintavirooj, C.
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Withayachumnankul, W.
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Sangworasil, M.
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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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Robotic arm controller using muscular contraction classification based on independent component analysis
(2008-10-06)
Chanwimalueang, T.
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Sueaseenak, D.
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Laoopugsin, N.
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Pintavirooj, C.
We develop a multi-channel electromyogram acquisition system base on the Programmable System On Chip (PSOC) microcontroller to control Robotic Arm. The array of 4 × 4 surface electrodes which invents from the low-cost EKG electrodes is used as the input sensor. B-spline interpolation technique has been utilized to map the EMG signal on the muscle surface. The topological mapping of the EMG is then analyzed to classify the pattern of muscle contraction. The proposed system was successfully demonstrated to record EMG data and its surface mapping. The muscular-contraction classification of mapping is then applied using independent component analysis. The classification result is then applied to control the movement of the robotic arm. © 2008 IEEE.
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Ultrasonic reflection mode tomography using frequency-shift method
(2006-12-01)
Tosranon, P.
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Onemanisone, T.
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Greesuradej, P.
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Pintavirooj, C.
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Jaruwongrungsee, K.
Tomogram of the soft tissue can be reconstructed by using its projections resolved from the ultrasonic broadband pulsed waves which are passed through the tissue. While a data from ultrasonic transmission mode tomography cannot be used to image the character of soft tissue where shadowed by a bone, an ultrasonic reflection mode tomography is realized to be a solution for this. There are many ways to extract the projections, in most case the integrated attenuation coefficients of the tissue from the pulsed wave. Almost all of these methods were proved to implement with the transmission mode signal, but however, some adaptation may takes benefit from those method to implement with the reflection mode. We choose the frequency-shift method to be analyzed because its advantage in a computational viewpoint. The simple filtered backprojection algorithm was implemented to reconstruct the tomographic images of the soft tissue suffered by bone. The results are shown the successful of this method over the transmission mode tomography. Also the simulations for noisy data were analyzed. © 2006 IEEE.
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Non-linear image registration using perspective invariant and thin-plate spine
(2004-12-01)
Putjarupong, P.
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Pintavirooj, C.
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Nantivatana, P.
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Withayachumnankul, W.
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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.

Pintavirooj, Chuchart

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