0 Agarwal, A. Rowberg, A. H. Kim, Y. 2003 IEEE Trans Inf Technol Biomed 7 184-90 1089-7771 (Print) 14518731 *Algorithms, Comparative Study, Hospital Information Systems/standards, Humans, *Hypermedia, Image Enhancement/*methods, Image Interpretation, Computer-Assisted/*methods, Information Storage and Retrieval/*methods/standards, Quality Control, *Radiology In Over the last decade, a picture archiving and communications system (PACS) has been accepted by an increasing number of clinical organizations. Today, PACS is considered as an essential image management and productivity enhancement tool. Image compression could further increase the attractiveness of PACS by reducing the time and cost in image transmission and storage as long as 1) image quality is not degraded and 2) compression and decompression can be done fast and inexpensively. Compared to JPEG, JPEG 2000 is a new image compression standard that has been designed to provide improved image quality at the expense of increased computation. Typically, the decompression time has a direct impact on the overall response time taken to display images after they are requested by the radiologist or referring clinician. In this paper, we present a fast JPEG 2000 decoder running on a low-cost programmable processor. It can decode a losslessly compressed 2048 x 2048 CR image in 1.51 s. Using this kind of a decoder, performing JPEG 2000 decompression at the PACS display workstation right before images are displayed becomes viable. A response time of 2 s can be met with an effective transmission throughput between the central short-term archive and the workstation of 4.48 Mb/s in case of CT studies and 20.2 Mb/s for CR studies. We have found that JPEG 2000 decompression at the workstation is advantageous in that the desired response time can be obtained with slower communication channels compared to transmission of uncompressed images. Evaluation StudiesJournal ArticleTwin StudyUnited Statesa publication of the IEEE Engineering in Medicine and Biology Society. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=14518731 31 Algorri, M. E. Haynor, D. R. Yongmin, Kim 1991 106-107 31 Ahmed, M. Blilie, D. E. Morgan, C. B. Lott, O. L. Greisen, M. V. Haynor, D. R. Kim, Y. 1991 776-777 31 Bae, U. Kim, Y. 2004 1 1345-1348 Vol.2 biomechanics, biomedical measurement, biomedical ultrasonics, cancer, elasticity, strain measurement, tumours, elastogram contrast to noise ratio, elastogram signal to noise ratio, lesion detectability, pathology, phase-based strain estimator, spatial cor Palpation has been widely used to detect hard tumorous tissues surrounded by softer normal tissues. The goal of ultrasound tissue elasticity imaging is to extract information regarding tissue stiffness that is closely related to pathology. For this tissue elasticity imaging, compression is applied first, and the amount of resulting tissue deformation or strain needs to be estimated. Traditionally, strain estimators aim to accurately derive tissue displacements between pre- and post-compression and compute strain from the displacements. However, the displacement can be as large as a thousand times of strain for typical compression levels used in ultrasound elasticity imaging. Error in displacement estimation leads to a large variance in strain, thus resulting in poor signal to noise ratio for the estimated strain. We have developed a novel strain estimator that directly estimates strain from the phase of temporal and spatial correlation instead of estimating small strain from large displacements. SNRe (signal to noise ratio of elastogram) and CNRe (contrast to noise ratio of elastogram) using the direct strain estimator are at least three times and six times larger than that using conventional displacement-based strain estimators, respectively. These results indicate that the direct strain estimator can significantly improve accuracy and lesion detectability in ultrasound elasticity imaging. In addition, the direct strain estimator is computationally efficient compared to conventional estimators, thus enabling the realtime implementation and clinical use of this new ultrasound imaging mode. 0 Bae, U. Shamdasani, V. Managuli, R. Kim, Y. 2003 J Digit Imaging 16 230-9 0897-1889 (Print) 14564661 Algorithms, Humans, Quality Assurance, Health Care, Radiographic Image Enhancement/*methods, *Signal Processing, Computer-Assisted, Software Unsharp masking is a widely used image-enhancement method in medical imaging. Hardware-based solutions can be developed to support high computational demand for unsharp masking, but they suffer from limited flexibility. Software solutions can easily incorporate new features and modify key parameters, such as filtering kernel size, but they have not been able to meet the fast computing requirement. Modern programmable mediaprocessors can meet both fast computing and flexibility requirements, which will benefit medical image computing. In this article, we present fast adaptive unsharp masking on two leading mediaprocessors or high-end digital signal processors, Hitachi/Equator Technologies MAP-CA and Texas Instruments TMS320C64x. For a 2k x 2k 16-bit image, our adaptive unsharp masking with a 201 x 201 boxcar kernel takes 225 ms on a 300-MHz MAP-CA and 74 ms on a 600-MHz TMS320C64x. This fast unsharp masking enables technologists and/or physicians to adjust parameters interactively for optimal quality assurance and image viewing. Journal ArticleUnited Statesthe official journal of the Society for Computer Applications in Radiology. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=14564661 31 Basoglu, C. Kim, Y. 1998 41 351 31 Bartoo, G. T. Kim, Y. Chang, D. 1995 1 31 Blilie, D. E. Kim, Y. Haynor, D. H. Guan, B. Chan, C. 1992 2 653-654 31 Bailey, T. Deffenbaugh, T. Kim, Y. 1992 4 1529-1530 31 Blilie, D. E. Fahy, J. B. Chan, C. Ahmed, M. Kim, Y. 1991 772-773 31 Blilie, D. E. Kim, Y. Morgan, C. Ahmed, M. 1990 1492-1493 31 Cho, P. S. Narayanan, S. Lam, S. T. Pathak, S. D. Tutar, I. B. Gong, L. Kim, Y. Wallner, K. E. 2004 10–3 31 Chung, C. Y. Managuli, R. A. Yongmin, Kim 2002 243-252 1063-6862 computer graphics, image texture, logic CAD, multimedia computing, parallel architectures, performance evaluation, pipeline processing, vector processor systems, video signal processing, 3D graphics pipeline, Imagine, VLIW architectures, Vector-IRAM, arch With the innovation and integration of media objects in multimedia applications, the importance of architectural support for different types of media objects, e.g., image, video and graphics, in one platform has significantly increased. While several approaches based on vector or VLIW (very long instruction word) architectures, e.g., Vector-IRAM and Imagine, have been pursued, they are not as effective as dedicated graphics pipelines for high-performance 3D graphics. We have explored a new programmable computing architecture based on a 3D graphics pipeline, which utilizes dedicated hardware resources in the 3D graphics pipeline for other types of multimedia computing. Adding programmable flexibility to a graphics pipeline for texture mapping has proven to be effective, e.g., pixel shader. However, due to the diversity of imaging and video processing applications, there are several challenges associated with converting a fixed graphics pipeline to a flexible multimedia computing engine. In this paper, we identify the additional architectural requirements, introduce the proposed architecture with extension details, and present the results of the performance evaluation. With cycle-accurate simulation of several benchmark functions, we have verified that the proposed architecture outperforms a modem powerful media processor in imaging and video processing by a factor of 1.3 to 7.5. The 3D graphics performance would not change much because the additional pipeline stages for the extension result in longer pipeline latency but similar throughout. 31 Czapski, P. Ramon, C. Huntsman, L. L. Bardy, G. H. Kim, Y. 1996 Institute of Physics Publishing 41 1247-1263 31 Czapski, P. Ramon, C. Huntsman, L. L. Bardy, G. H. Jorgenson, D. S. Kim, Y. 1993 897-898 31 Chan-Nui, C. Howard, M. Q. Nansel, R. L. Eiler, J. M. Kim, Y. 1991 1829-1830 31 Eung-Hun, Kim Modi, S. Fang, D. Soh, C. B. Herbaugh, A. Shinstrom, S. Lober, W. B. Zierler, B. Yongmin, Kim 2006 144-147 31 Eung-Hun, Kim Maisie, Wang Christopher, Lau Yongmin, Kim 2004 2 3159-3162 Internet, World Wide Web, patient-centered care, personal health record, referral, use statistics A web-based patient-centered personal health record (PHR), called the Personal Health Information Management System (PHIMS), has been developed and its usability has been evaluated in conjunction with a referral system, called the Facilitated Accurate Referral Management System (FARMS). To estimate the system requirements of PHIMS for wider clinical use, we have also studied PHIMS usage by analyzing server log files. A preliminary study showed 85% of survey respondents were satisfied with the usability and 94% were satisfied with the overall online referral process. The physicians were satisfied with the content of subjects' personal health information and found the information detailed enough to triage all requested referrals. 31 Fan, Zhang Yang Mo, Yoo Yongmin, Kim Lichen, Zhang Liang Mong, Koh 2006 2 1972-1977 1063-6919 A new noise reduction and edge enhancement method, i.e., Laplacian pyramid-based nonlinear diffusion and shock filter (LPNDSF), is proposed for medical ultrasound imaging. In the proposed LPNDSF, a coupled nonlinear diffusion and shock filter process is applied in Laplacian pyramid domain of an image, to remove speckle and enhance edges simultaneously. The performance of the proposed method was evaluated on a phantom and a real ultrasound image. In the phantom study, we obtained an average gain of 0.55 and 1.11 in contrast-to-noise ratio compared to the speckle reducing anisotropic diffusion (SRAD) and nonlinear coherent diffusion (NCD), respectively. Also, the proposed LPNDSF showed clearer boundaries on the phantom and the real ultrasound image. These preliminary results indicate that the proposed LPNDSF can effectively reduce speckle noise while enhancing image edges for retaining subtle features. 0 Flexman, J. A. Minoshima, S. Kim, Y. Miyoshi, S. Lewellen, B. L. Cross, D. J. 2006 IEEE Eng Med Biol Mag 25 70-5 0739-5175 (Print) 16898661 Animals, Drug Delivery Systems/*methods, Fluorine Radioisotopes/*administration , &, dosage/chemistry/*pharmacokinetics, Gene Targeting/*methods, Genetic Vectors/genetics, Male, Metabolic Clearance Rate, Organ Specificity, Radiopharmaceuticals/administrat P51 rr000166/rr/ncrrJournal ArticleUnited Statesthe quarterly magazine of the Engineering in Medicine & Biology Society. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=16898661 31 Flexman, J. A. Kim, Y. Miyoshi, S. Lewellen, B. L. Cross, D. J. Minoshima, S. 2005 793-796 Molecular imaging, biodistribution, positron emission tomography, viral envelope, Molecular imaging, biodistribution, positron emission tomography, viral envelope Viral envelopes can be used as an effective vehicle to deliver imaging tracers as well as therapeutic drugs and genes. However, the current methods for in vivo tracking of viral envelopes are limited. This purpose of this study is to investigate dynamically the in vivo biodistribution of viral envelopes using positron emission tomography (PET) imaging. The hemagglutinating virus of Japan envelope (HVJ-E) was labeled with radioactive fluorine (F-18) for tracking with PET imaging. Due to the low molecular weight of F-18, the encapsulation process by HVJ-E was optimized using the cationic agent poly-L-lysine (PLL, MW 66.7 kDa) and Feridex, a magnetic resonance imaging tracer. After labeling, HVJ-Es were injected intravenously into the normal rat and followed for 2 h using high resolution PET imaging. Region of interest analysis showed a significant increase in average liver accumulation based on radioactivity as compared to all control subjects. Average brain uptake showed a significant increase in radioactivity as compared to control subjects receiving F-18-PLL complexes or F-18 alone. Control subjects showed F-18 uptake primarily in the bones. These results demonstrate a molecular imaging technique that can be used to monitor drug and gene delivery and evaluate potential targeting mechanisms. 31 Flexman, J. A. Minoshima, S. Kim, Y. Miyoshi, S. Cross, D. J. Maravilla, K. Anzai, Y. 2004 2 5246-5249 Vol.7 biomedical MRI, biomembranes, cellular biophysics, iron compounds, magnetic particles, medical image processing, microorganisms, neurophysiology, patient treatment, FeO, Japan envelope, automated image analysis, cell membrane, contrast-enhanced cell track Stem cells represent a potentially revolutionary therapy for neurological pathologies but for which a thorough investigation of cell behavior in the living nervous system has yet to be performed. Contrast-enhanced cell tracking with magnetic resonance imaging can enable this investigation by introducing superparagmagnetic iron oxide (SPIO) particles within the cell membrane. Before magnetically labeled cells can be observed in vivo, it is essential to maximize SPIO transfer into the cell and to fully understand the localization of the contrast agent in mature neural cells. For practical applications, a quantitative evaluation of labeled cells before implantation will allow in vivo assertions. In this study, we present a comparison between two methods for magnetic transfection of neural progenitor cells: the hemmaglutinating virus of Japan envelope (HVJ-E) as a viral vector and a liposomal reagent. We show that HVJ-E is a more efficient vehicle of cell transfection using quantitative evaluation and that the iron content per cell can be predicted using a simple, automated image analysis of stained, labeled cells. Image analysis is also used in this study to show that the contrast agent is distributed in the axon after differentiation, an important aspect of understanding cell tracking in vivo. 31 Gong, L. Pathak, S. D. Haynor, D. R. Cho, P. S. Kim, Y. 2004 23 31 Gao, W. Mermer, C. Kim, Y. 2002 12 1150-1159 31 Guan, B. Haynor, D. R. Blilie, D. E. Chan, C. H. Kim, Y. 1992 2 651-652 31 Hilman, K. Park, H. W. Kim, Y. 2000 10 869-877 31 Huard, D. R. Eiler, J. M. Fleming, C. W. Nansel, R. L. Kim, Y. 1990 2303-2304 31 Jie, Liu Pagoulatos, N. Yongmin, Kim 2004 3 2189-2192 Vol.3 1051-0117 biological tissues, biomedical ultrasonics, deformation, image registration, image resolution, medical image processing, splines (mathematics), ultrasonic imaging, 2D slices, 3D ultrasound data, 3D volume, local deformation, multiresolution cubic B-spline Spatial compounding is very important for improving the quality of the 3D ultrasound data. The key to effective spatial compounding is accurate registration between the compounded data. In this paper, a new nonlinear deformable registration method for ultrasound spatial compounding is proposed. This novel method includes two steps. First, multiresolution cubic B-spline registration (MRBR) is applied to determine global and local nonlinear deformations following rigid registrations. Then 2D slice images are divided into partly overlapped sub-images to estimate the residual local deformations. Correlation ratio (CR) is used as the similarity metric. The results of in-vitro and in vivo trials demonstrated that we could get accurate registration using the new technique, which shows great promise for reducing tissue motion and local deformation in spatial compounding. 31 Jihong, Kim Yongmin, Kim 1996 76-83 circuit tuning, computer testing, digital signal processing chips, discrete cosine transforms, integrated circuit testing, multiprocessing systems, parallel architectures, performance evaluation, MVP Performance Monitor, Texas Instruments TMS320C80, block A new generation of high performance programmable digital signal processors (DSPs) has a highly-integrated parallel architecture, incorporating special-purpose hardware features, on-chip memory and multiple processors into a single chip. For such single-chip multiprocessor DSPs, however, a sophisticated performance monitoring tool is essential to achieve the maximum performance. The authors discuss the requirements and functionality of performance monitoring tools suitable for single-chip multiprocessor DSPs. As a specific example, they describe a performance monitoring tool developed for Texas Instruments' TMS320C80 (MVP), MVP Performance Monitor (MPM), which satisfies these requirements and functionality. The effectiveness of the MPM is demonstrated using an 8&times;8 block-based discrete cosine transform (DCT) implementation. An overall speed-up of 4.67 was achieved by using the MPM 31 Jihong, K. I. M. Yongmin, K. I. M. 31 Kim, E. Mayani, A. Modi, S. Kim, Y. Soh, C. B. 2005 593-596 Internet, PHIMS, World Wide Web, digital divide, housing authority, patient-centered care, personal health record, Internet, PHIMS, World Wide Web, digital divide, housing authority, patient-centered care, personal health record Advances and wide acceptance of information and communication technology (ICT) have made development and implementation of web-based electronic personal health records (PHRs) more feasible than ever before, and previous studies have demonstrated some of its potential and promises. However, this type of ICT-dependent approach inherits its own vulnerabilities of exposing the society to "digital divide", commonly described as the gap that exists among individuals and communities with regards to the 'haves' and 'have-nots' of information and modern communications technologies. To address these concerns and improve healthcare outcomes, we have developed and customized a web-based patient-centered electronic PHR, named the Personal Health Information Management System (PHIMS), and evaluated the system at the Everett Housing Authority, which provides housings for low-income families and elderly or disabled populations. A preliminary study demonstrates that 92% of the participating residents are satisfied with the PHIMS system in general. Some of the residents found PHIMS records very useful for their clinic visits. 31 Kim, Y. Fahy, J. B. DeSoto, L. A. Haynor, D. R. Loop, J. W. 2003 Springer 16 104-113 0 Karadayi, K. Markandey, V. Golston, J. Gove, R. J. Yongmin, Kim 2003 Micro, IEEE 23 58-70 computer architecture, multimedia computing, special purpose computers, mediaprocessing, mediaprocessors, multimedia, multimedia applications, peripheral interfaces, programmable processors For multimedia applications, mediaprocessors can achieve performance comparable to that of ASICs while remaining programmable and multifunctional. But a detailed understanding of the underlying architecture and algorithms is essential for developing efficient code. The authors present general strategies for mapping algorithms to mediaprocessors and discuss trends in mediaprocessing. 0272-1732 31 Kim, D. Managuli, R. Kim, Y. 2001 21 33-42 31 Kim, J. Kim, Y. Inc, T. I. Dallas, T. X. 1997 5 68-79 31 Kim, J. Kim, Y. 1993 10 6-15 31 Kim, Y. Park, H. W. Haynor, D. R. 1991 36-41 31 Kim, Y. Woo, H. W. Luedtke, A. E. 1989 8 46-49 31 Lau, C. Cabral, J. E. Rambhia, A. H. Kim, Y. 2003 SPIE 3976 573 31 Leotta, D. F. Kim, Y. 1993 12 62-69 31 Lixin Gong, M. S. E. Cho, P. S. Han, B. H. Wallner, K. E. Sutlief, S. G. Pathak, S. D. Haynor, D. R. Kim, Y. 500 90 31 Lau, C. Churchill, S. Kim, J. Matsen, F. A. Kim, Y. SPIE 693-698 0 Managuli, R. York, G. Kim, D. Kim, Y. 2006 Society of Photo-Optical Instrumentation Engineers 9 327-335 0 Michael, R. Neuman Yongmin, Kim 2006 Annals of Biomedical Engineering V34 226-231 10.1007/s10439-005-9036-x http://dx.doi.org/10.1007/s10439-005-9036-x 0 Minoshima, S. Wagner, H., Jr. Yongmin, Kim 2005 Proceedings of the IEEE 93 723-725 biological techniques, biomedical imaging, diseases, genetics, molecular biophysics, PET, biohybrid material, bioluminescence, cancer, genetics, in vivo human imaging, magnetic resonance imaging, molecular imaging, photonics, small animals Presents an introduction to a special issue on molecular imaging: emerging technology and biomedical applications. The paper illustrates the recent advances in molecular imaging, including aspects of basic molecular/genetic research up to in vivo human imaging. Developments of unique imaging technology to unveil molecular events are at the core of this research activity. In turn, such new techniques produce biomedical findings that could not be found by conventional imaging technology. The papers in this issue provide perspectives of this research field and the emergence of molecular imaging and applications. 0018-9219 31 Managuli, R. Yang Mo, Yoo Yongmin, Kim 2005 4 2046-2049 1051-0117 0 Miyoshi, S. Flexman, J. A. Cross, D. J. Maravilla, K. R. Kim, Y. Anzai, Y. Oshima, J. Minoshima, S. 2005 Mol Imaging Biol 7 286-95 1536-1632 (Print) 16080022 Animals, Biological Transport, Cell Death, *Cell Differentiation, Cell Division, Cell Survival, Cells, Cultured, Iron/*analysis/chemistry/isolation , &, purification/pharmacology, Magnetic Resonance Imaging/*methods, Nanostructures/*analysis/chemistry, N PURPOSE: Magnetic resonance imaging (MRI) can track labeled cells in the brain. The use of hemagglutinating virus of Japan envelopes (HVJ-Es) to effectively introduce the contrast agent to neural progenitor cells (NPCs) is limited to date despite their high NPC affinity. PROCEDURES: HVJ-Es and Lipofectamine 2000 were compared as transfection vehicles of superparamagnetic iron oxide (SPIO). Labeled NPCs were examined for iron content, MRI signal change, and fundamental cell characteristics. Prussian Blue staining was used after differentiation to determine SPIO localization. RESULTS: HVJ-Es transfected up to 12.5 +/- 8.8 times more SPIO into NPCs. HVJ-Es do not affect cell viability or differentiation capability. Superparamagnetic iron oxide was disseminated in both the soma and neurites. CONCLUSIONS: These findings indicate that HVJ-Es are an effective vehicle for SPIO transfection of NPCs. The intracellular localization after differentiation raises the question as to the capability of MRI to distinguish cell migration from axonal or dendritic growth in vivo. P51 rr000166/rr/ncrrJournal ArticleUnited StatesMIB : the official publication of the Academy of Molecular Imaging. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=16080022 31 Miyoshi, S. Flexman, J. A. Cross, D. J. Maravilla, K. R. Kim, Y. Anzai, Y. Oshima, J. Minoshima, S. 2005 Springer 7 286-295 31 Managuli, R. A. Kim, Y. 0 Neuman, M. R. Kim, Y. 2006 Springer 34 226-231 0 Park, H. W. Cheng, T. Kim, Y. 2006 Society of Photo-Optical Instrumentation Engineers 40 100-107 31 Park, H. W. Gopishankar, L. Kim, Y. 2002 Society of Photo-Optical Instrumentation Engineers 41 1232-1239 0 Pathak, S. D. Chalana, V. Haynor, D. R. Kim, Y. 2000 IEEE Trans Med Imaging 19 1211-9 0278-0062 (Print) 11212369 Algorithms, Humans, Image Enhancement, Male, Prostate/*ultrasonography Accurate detection of prostate boundaries is required in many diagnostic and treatment procedures for prostate disease. In this paper, a new paradigm for guided edge delineation is described, which involves presenting automatically detected prostate edges as a visual guide to the observer, followed by manual editing. This approach enables robust delineation of the prostate boundaries, making it suitable for routine clinical use. The edge-detection algorithm is comprised of three stages. An algorithm called sticks is used to enhance contrast and at the same time reduce speckle in the transrectal ultrasound prostate image. The resulting image is further smoothed using an anisotropic diffusion filter. In the third stage, some basic prior knowledge of the prostate, such as shape and echo pattern, is used to detect the most probable edges describing the prostate. Finally, patient-specific anatomic information is integrated during manual linking of the detected edges. The algorithm was tested on 125 images from 16 patients. The performance of the algorithm was statistically evaluated by employing five expert observers. Based on this study, we found that consistency in prostate delineation increases when automatically detected edges are used as visual guide during outlining, while the accuracy of the detected edges was found to be at least as good as those of the human observers. The use of edge guidance for boundary delineation can also be extended to other applications in medical imaging where poor contrast in the images and the complexity in the anatomy limit the clinical usability of fully automatic edge-detection techniques. Journal ArticleUnited States http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=11212369 31 Pathak, S. D. Chalana, V. Haynor, D. R. Kim, Y. 1999 2 1056 vol.2 biological organs, biomedical ultrasonics, edge detection, image enhancement, image segmentation, medical expert systems, medical image processing, surface fitting, Canny edge detector, contrast enhancement, deformable membrane fitting, deformable surface Prostate boundaries form the basis of many diagnosis/treatment procedures for prostate diseases. In this paper, a new paradigm of edge guidance is described that involves just-enough-interaction with the expert, leading to robust delineation of the prostate boundaries. We statistically show that an increase in the consistency and the accuracy of prostate delineation is achieved using the edges as visual guide 31 Pagoulatos, N. Haynor, D. R. Kim, Y. 1999 2 31 Pagoulatos, N. Edwards, W. S. Haynor, D. R. Kim, Y. 1999 3 31 Ramon, C. Czapski, P. Haueisen, J. Huntsman, L. L. Nowak, H. Bardy, G. H. Leder, U. Kim, Y. Nelson, J. A. 1998 45 1323 31 Ritchie, C. J. Yongmin, Kim Crawford, C. R. Godwin, J. D. 1992 5 1782-1783 31 Ritchie, C. J. Peterson, E. Yee, D. Kim, Y. Godwin, J. D. Crawford, C. R. 1989 487-488 31 Sikdar, S. Shamdasani, V. T. Lidstrom, M. S. Beach, K. W. Yongmin, Kim 2006 55-58 0 Schneider, F. K. Yoo, Y. M. Agarwal, A. Koh, L. M. Kim, Y. 2006 Ultrasonics 44 265-71 0041-624X (Print) 16563453 Humans, *Image Enhancement, Phantoms, Imaging, Research Support, Non-U.S. Gov, ', t, *Signal Processing, Computer-Assisted, Ultrasonography/*instrumentation In this paper, we present a new quadrature demodulation filter to reduce hardware complexity in digital phase rotation beamforming. Due to its low sensitivity to phase delay errors, digital quadrature demodulation is commonly used in ultrasound machines. However, since it requires two lowpass filters for each channel to remove harmonics, the direct use of conventional finite impulse response (FIR) filters in ultrasound machines is computationally expensive and burdensome. In our new method, an efficient multi-stage uniform coefficient (MSUC) filter is utilized to remove harmonic components in phase rotation beamforming. In comparison with the directly implemented FIR (DI-FIR) and the previously-proposed signed-power-of-two FIR (SPOT-FIR) lowpass filters, the proposed MSUC filter reduces the necessary hardware resources by 93.9% and 83.9%, respectively. In simulation, the MSUC filter shows a negligible degradation in image quality. The proposed method resulted in comparable spatial and contrast resolution to the DI-FIR approach in the phantom study. These preliminary results indicate that the proposed quadrature demodulation filtering method could significantly reduce the hardware complexity in phase rotation beamforming while maintaining comparable image quality. Journal ArticleNetherlands http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=16563453 0 Sikdar, S. Beach, K. W. Paun, M. Vaezy, S. Kim, Y. 2006 Ultrasound Med Biol 32 1203-14 0301-5629 (Print) 16875955 Animals, Femoral Artery/*injuries/*ultrasonography, Hemorrhage/ultrasonography, Liver/*injuries/*ultrasonography, Rabbits, Research Support, U.S. Gov, ', t, Non-P.H.S., *Signal Processing, Computer-Assisted, Swine, *Ultrasonography, Doppler, Color, Vibrat Soft tissues surrounding vascular injuries are known to vibrate at audible and palpable frequencies, producing bruits and thrills. We report the results of a feasibility study where Doppler ultrasound (US) was used to quantitatively estimate the tissue vibrations after induced trauma in an animal model. A software-programmable US system was used to acquire quadrature-demodulated ensembles of received US echoes bypassing clutter filtering and other conventional Doppler processing stages. The waveforms of tissue velocity surrounding the injury site were then estimated from the clutter data using autocorrelation and analyzed to determine vibration characteristics. Six New Zealand white rabbits and two juvenile pigs were used for the study. The femoral artery of the anesthetized animal was punctured with an 18-gauge needle to model a peripheral arterial trauma, and the liver was surgically exposed and incised to model organ trauma. Two types of oscillatory tissue motion were observed: "vibrations" with high frequency (>50 Hz) and low peak-peak amplitude (<1 microm) and "flutter" with low frequency (<50 Hz) and high peak-peak amplitude (>1 microm). Active bleeding in femoral artery punctures produced tissue vibrations at the frequency of 323 +/- 214 Hz (mean +/- standard deviation, pooled for both rabbits and pigs) and the amplitude of 0.24 +/- 0.15 microm. Active bleeding in liver incisions produced vibrations at the frequency of 120 +/- 47 Hz and the amplitude of 0.33 +/- 0.25 microm. Flutter was observed in punctured arteries at the frequency of 28 +/- 13 Hz the amplitude of 2.92 +/- 1.75 microm, and in incised livers at the frequency of 26 +/- 6 Hz and the amplitude of 1.53 +/- 0.76 microm. In a punctured artery, the vibration frequency and phase of tissue surrounding the artery were highly correlated between neighboring locations in tissue (correlation coefficient = 0.98), and with the flow oscillations in the lumen (correlation coefficient = 0.96). This preliminary study indicates that tissue vibrations could provide additional physiologic information for detecting, localizing and monitoring internal bleeding using US. Journal ArticleEngland http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=16875955 2 Sikdar, Siddhartha 2005 University of Washington, 2005. xi, 259 leaves Engr Stacks-Floors 3&4 T Ultrasonics in medicine., Acoustic imaging., Ultrasonic imaging., Tissues ultrasonography., Theses Electrical engineering. Siddhartha Sikdar.col. ill. ; 28 cm.Vita.Includes bibliographical references (leaves 237-256). 31 Sikdar, S. Beach, K. W. Goldberg, S. L. Zwink, T. R. Baughman, L. I. Kim, Y. 2005 1087-1090 Coronary artery disease, cardiac murmurs, myocardial vibrations, ultrasound, Coronary artery disease, cardiac murmurs, myocardial vibrations, ultrasound Coronary artery disease (CAD) is a major cause of mortality in the western world. Although progress has been made in recent years for the noninvasive diagnosis of CAD, a widely available, inexpensive and effective diagnostic solution remains elusive. We have developed a novel ultrasound-based technology to detect and analyze the myocardial vibrations associated with diastolic murmurs produced by CAD. Conventional ultrasound imaging systems suppress these vibrations. We have developed algorithms to process the raw ultrasound data and isolate these vibrations and integrated them into a programmable ultrasound system for real-time vibration imaging. In preliminary results from clinical studies of patients with CAD, we have observed localized areas of vibrations in the neighborhood of the stenosed coronary artery. The vibrations are narrowband with frequency &gt;200 Hz, and appear to have harmonic components, thus indicating reasonance phenomena potentially with nonlinear mechanisms involved. No such vibrations were observed in normal subjects. Analysis of myocardial vibrations could provide a noninvasive diagnostic test for CAD that overcomes many of the limitations of conventional noninvasive tests. Potentially, this technology could provide a new way of evaluating CAD and cardiac function. 0 Sikdar, S. Beach, K. W. Vaezy, S. Kim, Y. 2005 Ultrasound Med Biol 31 221-32 0301-5629 (Print) 15708462 *Algorithms, Arteriovenous Shunt, Surgical, Blood Vessels/*ultrasonography, Constriction, Pathologic/ultrasonography, Femoral Artery/ultrasonography, Femoral Vein/ultrasonography, Humans, Image Enhancement/methods, Phantoms, Imaging, Regional Blood Flow/p We propose an ultrasound (US)-based technique for imaging vibrations in the blood vessel walls and surrounding tissue caused by eddies produced during flow through narrowed or punctured arteries. Our approach is to utilize the clutter signal, normally suppressed in conventional color flow imaging, to detect and characterize local tissue vibrations. We demonstrate the feasibility of visualizing the origin and extent of vibrations relative to the underlying anatomy and blood flow in real-time and their quantitative assessment, including measurements of the amplitude, frequency and spatial distribution. We present two signal-processing algorithms, one based on phase decomposition and the other based on spectral estimation using eigen decomposition for isolating vibrations from clutter, blood flow and noise using an ensemble of US echoes. In simulation studies, the computationally efficient phase-decomposition method achieved 96% sensitivity and 98% specificity for vibration detection and was robust to broadband vibrations. Somewhat higher sensitivity (98%) and specificity (99%) could be achieved using the more computationally intensive eigen decomposition-based algorithm. Vibration amplitudes as low as 1 mum were measured accurately in phantom experiments. Real-time tissue vibration imaging at typical color-flow frame rates was implemented on a software-programmable US system. Vibrations were studied in vivo in a stenosed femoral bypass vein graft in a human subject and in a punctured femoral artery and incised spleen in an animal model. Journal ArticleEngland http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=15708462 31 Shamdasani, V. Kim, Y. 2004 1 1380-1383 Vol.2 biological tissues, biomechanics, biomedical measurement, biomedical ultrasonics, correlation methods, displacement measurement, gelatin, numerical analysis, phantoms, strain measurement, gelatin phantoms, signal-to-noise ratio, speckle, strain estimation Ultrasound strain imaging maps the tissue stiffness in the region of interest by estimating strain when the tissue is stressed. Prestress and poststress ultrasound echoes are processed to estimate the displacements, and the strain image is computed by a spatial derivative of the estimated displacement. Due to the nature of derivative operations, smaller errors in displacement estimation can cause large noise in the computed strain image. When tissue displacements are estimated using the phase of the autocorrelation between the prestress and poststress data (i.e., 1D autocorrelation method), it has been previously reported that local variations in ultrasonic center frequency due to speckle can introduce errors in the estimated displacement. We have developed a new method to compute strain based on two-dimensional autocorrelation. By estimating the local ultrasound frequency, we can improve the accuracy of displacement estimates and hence reduce the noise in strain images. We have analyzed the effect of local frequency changes on noise in strain images and the improvement in the strain signal-to-noise ratio with the 2D autocorrelation method. The simulation results are supported by experiments with homogenous gelatin phantoms and show that strain signal-to-noise ratio with 2D autocorrelation is consistently higher than that with 1D autocorrelation. The 2D autocorrelation can increase the strain signal-to-noise ratio by up to 200%, which leads us to believe that our estimation method can significantly improve the quality of strain images. 31 Sikdar, S. Kim, Y. Leotta, D. F. Primozich, J. F. Beach, K. W. 2004 1 1325-1328 Vol.2 Doppler effect, bioacoustics, biomechanics, biomedical ultrasonics, blood vessels, vibrations, audible bruits, carotid stenoses, color-Doppler ultrasound, post-stenotic jet, pulsed-wave Doppler ultrasound, quantitative analysis, residual lumen diameter, s Arterial stenoses are often associated with audible bruits. Quantitative analysis of the bruit spectrum has been successfully used to predict the residual lumen diameter in carotid stenoses. Arterial wall vibrations occurring due to turbulent pressure fluctuations in the post-stenotic jet are known to be the source of the bruits. We present novel signal processing techniques that enable the detailed noninvasive assessment of these vibrations in real time using color-Doppler and pulsed-wave Doppler ultrasound. A color-Doppler-based two-dimensional vibration imaging technique can be used to locate the source of the bruits relative to the underlying anatomy. Subsequently, a pulsed-wave Doppler-based technique can be used to analyze the bruit spectrum quantitatively. Experiments in ex vivo arteries indicate that these techniques can predict the location of the bruit as well as its spectral content. Case studies on human subjects with stenosed vein grafts are presented and the clinical applicability of this technique is discussed. 0 Shamdasani, V. Managuli, R. Sikdar, S. Kim, Y. 2004 IEEE Trans Inf Technol Biomed 8 191-9 1089-7771 (Print) 15217264 *Algorithms, Blood Flow Velocity, Comparative Study, Equipment Design, Equipment Failure Analysis, Image Enhancement/*instrumentation/*methods, Image Interpretation, Computer-Assisted/*instrumentation/*methods, Reproducibility of Results, Sensitivity and Color-flow imaging is a well-established ultrasound mode and very valuable for visualizing in real time the distribution of blood flow in a specific region of interest. However, it is computationally quite expensive. To meet the large computational need in color-flow imaging, most ultrasound systems have been designed using fixed-function hardware. In this paper, we present a system where all the color-flow processing is supported on a programmable platform. About 95% of the processing modules were programmed in C language. On a single processor, we were able to achieve 7.9 frames/s, when the input data consist of 192 x 512 x 8 (ensemble size) samples for color flow and 384 x 512 for B mode and the output image size is 600 x 420. Additional processors can be added to handle more input data and/or support higher frame rates. Our results demonstrate that a programmable ultrasound system can provide the same functionality for clinical use as conventional ultrasound systems. However, it is more flexible and efficient due to its programmability. Evaluation StudiesJournal ArticleValidation StudiesUnited Statesa publication of the IEEE Engineering in Medicine and Biology Society. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=15217264 31 Sun, S. Park, H. W. Haynor, D. R. Kim, Y. 2003 13 169-178 31 Sun, S. Haynor, D. R. Kim, Y. 2003 13 75-82 0 Sikdar, S. Managuli, R. Gong, L. Shamdasani, V. Mitake, T. Hayashi, T. Kim, Y. 2003 IEEE Trans Inf Technol Biomed 7 64-70 1089-7771 (Print) 12670020 Algorithms, Ultrasonography/*instrumentation We have developed a programmable ultrasound imaging system using a single commercially available mediaprocessor. We have efficiently mapped all of the necessary B-mode processing algorithms on the underlying processor architecture, including envelope detection, dynamic range compression, lateral and axial filtering, persistence processing, and scan conversion. Our system can handle varying specifications ranging from 128 vectors and 512 samples per vector to more than 256 vectors and 1024 samples per vector. For an image size of 330 vectors and 512 samples per vector, it can process 30 frames per second using a 300-MHz MAP-CA mediaprocessor from Hitachi/Equator Technologies. This programmable ultrasound machine will not only offer significant advantages in terms of low cost, portability, scalability, and reduced development time, but also provide a flexible platform for developing and deploying new clinical applications to aid the clinicians and improve the quality of healthcare to patients. LetterUnited Statesa publication of the IEEE Engineering in Medicine and Biology Society. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=12670020 31 Sikdar, S. Vaezy, S. Beach, K. W. Yongmin, Kim 2003 2 1820-1823 Vol.2 biomedical ultrasonics, blood vessels, ultrasonic imaging, vibration measurement, vibrations, 2D ultrasonic imaging, arterial bleeding, blood flow, pulsatile wall motion, tissue vibrations, transcutaneous localization Arterial bleeding into a free space is known to cause local vibrations in tissue. To study the effectiveness of utilizing these tissue vibrations in localizing the site of arterial bleeding, we have developed an algorithm for ultrasonically imaging these tissue vibrations. Simulation results indicate that our algorithm can correctly detect vibrations in the presence of pulsatile wall motion, blood flow and noise with the sensitivity of 96% and specificity of 99%. Preliminary results from an animal study indicate that our algorithm can detect vibrations from bleeding arteries as well as from organs such as liver and spleen. 31 Shijun, Sun Haynor, D. R. Yongmin, Kim 2002 2 II-741-II-744 vol.2 1522-4880 edge detection, image segmentation, tracking, video signal processing, VSnakes, contour segment, edge energy change ratio, local affine correction, local deformations, object boundary, object contour, segmentation, video object tracking An algorithm is introduced for video object tracking and segmentation that automatically detects local deformations of a video object and adjusts the object contour to match the real object boundary without breaking the object into several pieces during tracking. An edge energy change ratio is defined for local deformation detection. The corresponding contour segment is then adjusted to the real object boundary based on a local affine correction. Incorporating this method into VSnakes, our general algorithm for video object tracking, resulted in improved performance. 31 Schoepflin, T. Lau, C. Garg, R. Kim, D. Kim, Y. 2001 667-675 2 Sikdar, Siddhartha 2001 University of Washington, 2001. iii, 32 leaves Engr Stacks-Floors 3&4 T Ultrasonic imaging., Imaging systems Design and construction., Theses Electrical engineering. Siddhartha Sikdar.ill. ; 29 cm.Includes bibliographical references (leaves 30-32) 31 Shijun, Sun Haynor, D. Yongmin, Kim 2000 1 852-855 vol.1 adaptive signal processing, gradient methods, image sequences, motion estimation, Gauss-Seidel iterative method, adaptive gradients, backward image gradient, double-image artifacts elimination, forward image gradient, image occlusions, image sequences, mo Optical flow has been widely used in motion estimation. By initializing adaptive gradients, we have developed a technique to reduce the occlusion problem in computing optical flow with the Horn and Schunck (1981) method. The adaptive gradients are derived from the forward and backward image gradients based on the optical flow equation during iterations. Improved optical flow solutions with the elimination of `double-image' artifacts caused by occlusions have been obtained 31 Thomas, M. A. Rowberg, A. H. Langer, S. G. Kim, Y. 2004 Springer 17 189-195 0 Tutar, I. B. Managuli, R. Shamdasani, V. Cho, P. S. Pathak, S. D. Kim, Y. 2003 Med Phys 30 3135-42 0094-2405 (Print) 14713080 Brachytherapy/instrumentation/*methods, Comparative Study, Foreign Bodies/*radiography, Humans, Imaging, Three-Dimensional/*methods, Male, Phantoms, Imaging, Prostatic Neoplasms/*radiography/*radiotherapy, Radiographic Image Interpretation, Computer-Assis Accurately assessing the quality of prostate brachytherapy intraoperatively would be valuable for improved clinical outcome by ensuring the delivery of a prescribed tumoricidal radiation dose to the entire prostate gland. One necessary step towards this goal is the robust and rapid localization of implanted seeds. Several methods have been developed to locate seeds from x-ray projection images, but they fail to detect completely-overlapping seeds, thus necessitating manual intervention. To overcome this limitation, we have developed a new method where (1) a three-dimensional volume is reconstructed from x-ray projection images using a brachytherapy-specific tomosynthesis reconstruction algorithm with built-in blur compensation and (2) the seeds are located in this reconstructed volume. In contrast to other projection-based methods, our method can detect completely overlapping seeds. Our simulation results indicate that we can locate all implanted seeds in the prostate using a tomosynthesis angle of 30 degrees and seven projection images. The mean localization error is 1.27 mm for a case with 100 seeds. We have also tested our method using a prostate phantom with 61 implanted seeds and succeeded in locating all seeds automatically. We believe this new method can be useful for the intraoperative quality assessment of prostate brachytherapy in the future. Evaluation StudiesJournal ArticleValidation StudiesUnited States http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=14713080 31 White, C. C. Fang, D. Eung-Hun, Kim Lober, W. B. Yongmin, Kim 2006 168-172 0 Wang, P. Kim, Y. Soh, C. B. 2005 7572-7575 0 Wang, P. Kim, Y. Ling, L. H. Soh, C. B. 2005 5519-5522 31 Wang, M. Lau, C. Matsen Iii, F. A. Kim, Y. 2004 8 287-297 31 Wickes, B. T. Kim, Y. Castner, D. G. 2003 35 640-648 31 Wang, Y. Haynor, D. R. Kim, Y. 2001 48 1390-1401 31 Wang, Y. Haynor, D. R. Kim, Y. 2001 48 1377-1389 31 Wang, Y. Schimpf, P. H. Haynor, D. R. Kim, Y. 1998 45 877-884 31 Wang, X. Ritchie, C. J. Kim, Y. 1996 15 389-394 31 Wong, A. C. Lew, A. Nansel, R. L. Eiler, J. M. Kim, Y. 1991 1869-1870 31 Wang, M. Lau, C. Matsen Iii, F. A. Kim, Y. 31 Yongmin, Kim 2006 iii-iii 31 Yang Mo, Yoo Schneider, F. K. Agarwal, A. Fukuoka, T. Liang Mong, Koh Yongmin, Kim 2006 63-66 31 Yifan, Chen Gunawan, E. Yongmin, Kim Kaysoon, Low Cheongboon, Soh 2006 255-258 cancer, microwave imaging, microwave propagation, sensor fusion, time-of-arrival estimation, ultra wideband technology, CLEAN algorithm, IR component extraction, TOA data fusion, UWB microwave imaging, breast cancer detection, clutter identification, domi This paper proposed a novel scheme for early breast cancer detection using UWB microwave imaging. By applying the CLEAN algorithm to process the received signals at each sensor, the IR components can be successfully resolved. The locations and scattering strengths of dominant scatterers are then estimated based on the TOA data fusion concept. Simulation results have indicated the feasibility of detecting a tumor of 2 mm at depth of 2 cm. As compared to the existing techniques, the proposed approach is more computationally-efficient since the scanning process is localized at a few candidate locations. A number of issues that need to be addressed in future include: (i) effectiveness of the proposed approach for 3-D phantoms with realistic breast shapes and tissue compositions; (ii) extension of analysis to more complicated antenna array systems; (iii) other signal processing algorithms that may provide better IR component extraction and scatterer location estimation. 31 Yongmin, Kim 2004 119-130 31 Yongmin, Kim 2004 2 5216 Vol.7 Internet, biomedical equipment, controllers, diseases, health care, medical diagnostic computing, patient diagnosis, telemedicine, Web servers, arthritis, biomedical informatics, chronic disease, communications, databases, diabetes, distributed diagnosis, The traditional healthcare system is characterized by hospital or clinic-based face-to-face contacts between the patient and care provides, which frequently occur at times and locations that are inconvenient or difficult for the patient. The healthcare delivery in the future needs to be provided in a distributed, patient-centered manner. The distributed diagnosis and home healthcare (D2H2) will benefit patients, particularly those with chronic disease, e.g., diabetes, arthritis, and high blood pressure, by improving the quality, convenience and efficiency of care, reducing the healthcare cost, and preventing medical errors, thus leading to increasing access to affordable and effective healthcare. There are many important components to make the D2H2 vision a reality: (1) physiological measurement and point-of-care diagnostic devices that can be used at the place where the patient is, e.g., home and nursing home, (2) a home-based controller, (3) communications and networking, (4) databases, Web servers and services, (5) biomedical informatics, (6) intelligent agents, and (7) system integration, reliability and security. We believe that the paradigm change from central, hospital-based to distributed, patient-centered, home-based healthcare delivery is inevitable. There are many opportunities for engineers and scientists to innovate and contribute to this 21st century healthcare system. 31 Yongmin, Kim 2004 131-142 31 Yoo, Y. M. Kim, Y. 2004 1 1337-1340 Vol.2 biomedical ultrasonics, blood vessels, clutter, eigenvalues and eigenfunctions, image colour analysis, medical image processing, phantoms, spectral analysis, 3.4 dB, 4.1 dB, adaptive clutter rejection, clutter characteristics, clutter filter, clutter sign We have developed a new adaptive clutter rejection technique where an optimum clutter filter is dynamically selected according to the varying clutter characteristics in ultrasound color-flow imaging. The selection criteria have been established based on spectral analysis of an estimate of the temporal autocorrelation matrix of clutter signals. The performance of the clutter rejection techniques is quantified from a wall-less flow phantom and in vivo studies. The in vivo color-flow images obtained from hepatic veins are presented to illustrate the potential of the proposed adaptive clutter rejection technique. In hepatic vein in vivo studies, we obtained an average gain of 4.1 dB and 3.4 dB in flow signal-to-clutter-ratio compared to the conventional and down-mixing methods, respectively. 31 Yongmin, Kim 2004 2 5139 Vol.7 biomedical equipment, industrial property, technology transfer, academic labs, intellectual property management, medical devices, technology transfer Summary form only given. A wealth of innovation comes from the academic community. In order to make this innovation useful to the public, the technology is typically transferred to the industry sector where the ideas are developed into a product that can be robust, safe and effective. The workshop leaders shared their great experience in transferring technology from their academic labs and managing intellectual property. 0 Yoo, Y. M. Managuli, R. Kim, Y. 2003 Ultrasound Med Biol 29 1311-20 0301-5629 (Print) 14553809 Algorithms, Blood Flow Velocity, Blood Vessels/physiology/*ultrasonography, Computer Simulation, Humans, Image Processing, Computer-Assisted/*methods, Ultrasonography, Doppler, Color/*methods In this article, we present an adaptive clutter rejection method for selecting different clutter filters in ultrasound color flow imaging. A single clutter filter is typically used to reject the clutter. Because the clutter characteristics vary in both space and time, the single clutter filter approach has difficulty in providing optimum clutter rejection in ultrasound images. To achieve more accurate velocity estimation, we have developed a method to select a clutter filter adaptively at each location in an image from a set of predefined filters. Selection criteria have been developed based on the underlying clutter characteristics and the properties of various filters (e.g., minimum-phase finite impulse response, projection-initialized infinite impulse response and polynomial regression). We have incorporated our adaptive clutter rejection method in an ultrasound system. We have found that our adaptive method can reduce the mean absolute error between the estimated and true flow velocities significantly compared with the conventional methods, in which a single clutter filter is used throughout the entire image. With in vivo abdominal data, we obtained an average gain of 5.0 dB in signal-to-clutter ratio (SCR), compared with the conventional method. These preliminary results indicate that the proposed adaptive method could improve the accuracy of flow velocity estimation in ultrasound color flow imaging through the improvement in SCR and the reduction in bias. Evaluation StudiesJournal ArticleEngland http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=14553809 31 Yongmin, Kim Jaehong, Park 2003 1 475-479 Vol.1 0191-2216 eigenvalues and eigenfunctions, fault diagnosis, filters, invariance, linear systems, closed loop eigenvectors, detection filters, disturbance attenuation, eigenvalues, invariant zero vector, linear equations, one-to-one correspondence This paper investigates the response characteristics of detection filters and proposes a condition of disturbance attenuation by analyzing the distribution of the closed-loop eigenvectors with respect to the eigenvalues. As an invariant factor of the detection space, invariant zeros are selected. It is shown that the closed-loop eigenvectors are determined by the linear equations of eigenvalues utilizing the one-to-one correspondence between the eigenvectors and the invariant zero vectors. Based on this result, we present a condition of the eigenvalues associated with the disturbances to reduce their effect in the output space for the case of disturbance accommodation. 31 Yoochang, Jung Berg, S. G. Donglok, Kim Yongmin, Kim 2000 559-560 computer architecture, discrete cosine transforms, video signal processing, 2D convolution, 2D discrete cosine transform, 2D separable image, column-wise processing, partitioned instructions, register file architecture, transposed access mode, transpositi We introduce a new register file architecture that provides both row-wise and column-wise accesses, thus allowing partitioned instructions to be used in column-wise processing without transposition overhead. This feature can accelerate 2D separable image and video processing algorithms, such as 2D convolution and 2D discrete cosine transform (DCT), by eliminating the transposition steps 31 Yongmin, Kim Jaehong, Park 1999 6 3810-3814 vol.6 fault diagnosis, filtering theory, invariance, linear systems, matrix algebra, multivariable systems, observers, poles and zeros, detection filter, detection spaces, invariant zeros, observable canonical form, poles selection An algorithm for obtaining the detection generators is proposed in terms of the invariant zeros using the observable canonical form of multivariable systems. The result of the paper is more efficient than the former result, and can clearly explain the special property of the detection filter. It is shown that the invariant zeros can be used as an important criterion when selecting the poles of the detection filter 31 York, G. Kim, Y. 1999 1 559-588 31 Yongmin, Kim 1997 33-37 biomedical ultrasonics, digital signal processing chips, medical image processing, multimedia computing, real-time systems, MediaStation 5000, computer-based systems, cost/performance ratios, high-quality multi-channel audio, high-resolution images, highl Multimedia technology is gaining wide acceptance in desktop computing and commercial and consumer applications due to its high performance, lower cost, and higher level of integration. Multimedia allows computer-based systems to deliver information to the user in ways other than the traditional methods of text. The new forms of information delivery include high-resolution images, realistic 2D and 3D graphics, high-quality multi-channel audio, and real-time video. By taking advantage of this new information delivery mechanism, with a continuing improvement in cost/performance ratios, many new applications are emerging in various fields. Digital video, video teleconferencing, machine vision, digital consumer electronics, and education and training are a few such examples. During the past ten years, the author has been working on applying multimedia technologies to medical applications. The author developed a highly-integrated desktop multimedia system called MediaStation 5000 and explored various application areas in medicine. The author has also successfully designed, implemented, and commercialized the programmable ultrasound image processor (PUIP) to fit within an ultrasound machine. It provides a platform for rapid testing of new concepts in ultrasound processing and enables software upgrades for future technologies 31 Yongmin, Kim Haynor, D. R. 1991 111-116 31 Yongmin, Kim Haass, C. D. 1990 219-220