Dr. Raymond C. Chan Profile

Dr. Raymond C. Chan

Senior Member Research Staff at Philips Research North America

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Publications (15)

Proceedings Article | 24 February 2010 Paper

Absolute vs. relative error characterization of electromagnetic tracking accuracy

Mohammad Matinfar, Ganesh Narayanasamy, Luis Gutierrez, Raymond Chan, Ameet Jain

Proceedings Volume 7625, 762524 (2010) https://doi.org/10.1117/12.844326

KEYWORDS: Sensors, Calibration, Environmental sensing, Electromagnetism, Error analysis, Optical tracking, Visualization, X-rays, Navigation systems, Phase measurement

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Electromagnetic (EM) tracking systems are often used for real time navigation of medical tools in an Image Guided Therapy (IGT) system. They are specifically advantageous when the medical device requires tracking within the body of a patient where line of sight constraints prevent the use of conventional optical tracking. EM tracking systems are however very sensitive to electromagnetic field distortions. These distortions, arising from changes in the electromagnetic environment due to the presence of conductive ferromagnetic surgical tools or other medical equipment, limit the accuracy of EM tracking, in some cases potentially rendering tracking data unusable. We present a mapping method for the operating region over which EM tracking sensors are used, allowing for characterization of measurement errors, in turn providing physicians with visual feedback about measurement confidence or reliability of localization estimates. In this instance, we employ a calibration phantom to assess distortion within the operating field of the EM tracker and to display in real time the distribution of measurement errors, as well as the location and extent of the field associated with minimal spatial distortion. The accuracy is assessed relative to successive measurements. Error is computed for a reference point and consecutive measurement errors are displayed relative to the reference in order to characterize the accuracy in near-real-time. In an initial set-up phase, the phantom geometry is calibrated by registering the data from a multitude of EM sensors in a non-ferromagnetic ("clean") EM environment. The registration results in the locations of sensors with respect to each other and defines the geometry of the sensors in the phantom. In a measurement phase, the position and orientation data from all sensors are compared with the known geometry of the sensor spacing, and localization errors (displacement and orientation) are computed. Based on error thresholds provided by the operator, the spatial distribution of localization errors are clustered and dynamically displayed as separate confidence zones within the operating region of the EM tracker space.

Proceedings Article | 27 March 2009 Paper

A multi-modality segmentation framework: application to fully automatic heart segmentation

Carsten Meyer, Olivier Ecabert, Jochen Peters, Reinhard Kneser, Robert Manzke, Raymond Chan, Jürgen Weese

Proceedings Volume 7259, 72594L (2009) https://doi.org/10.1117/12.810919

KEYWORDS: Image segmentation, 3D image processing, Magnetic resonance imaging, X-ray computed tomography, 3D modeling, Heart, X-rays, Target detection, Data modeling, Calibration

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Proceedings Article | 6 March 2009 Paper

Novel echocardiographic prediction of non-response to cardiac resynchronization therapy

R. Chan, F. Tournoux, A. Tournoux, V. Nandigam, R. Manzke, S. Dalal, J. Solis-Martin, D. McCarty, J. Ruskin, M. Picard, A. Weyman, J. Singh

Proceedings Volume 7262, 726229 (2009) https://doi.org/10.1117/12.811875

KEYWORDS: CRTs, Heart, Tissues, Doppler effect, MATLAB, Medicine, Hemodynamics, Echocardiography, Atrial fibrillation, Imaging systems

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Proceedings Article | 17 March 2008 Paper

Epicardial ablation guidance using coronary arterial models and live fluoroscopic overlay registrations

R. Manzke, A. Thiagalingam, B. Movassaghi, A. d'Avila, V. Reddy, R. Chan

Proceedings Volume 6918, 69181S (2008) https://doi.org/10.1117/12.770271

KEYWORDS: 3D modeling, Arteries, Animal model studies, X-rays, Angiography, Motion models, Fluoroscopy, Visualization, 3D acquisition, Sensors

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Proceedings Article | 13 March 2008 Paper

Image-based speckle tracking for tissue motion characterization in a deformable cardiovascular phantom

R. Chan, R. Manzke, S. Dalal, D. Stanton, P. Chang, S. Settlemier, I. Salgo, F. Tournoux

Proceedings Volume 6920, 69200U (2008) https://doi.org/10.1117/12.770631

KEYWORDS: Tissues, Speckle, Computed tomography, Ultrasonography, Prototyping, Crystals, Medical research, Detection and tracking algorithms, Acoustics, Imaging systems

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Proceedings Article | 22 March 2007 Paper

Rapid fusion of 2D x-ray fluoroscopy with 3D multislice CT for image-guided electrophysiology procedures

Lyubomir Zagorchev, Robert Manzke, Ricardo Cury, Vivek Reddy, Raymond Chan

Proceedings Volume 6509, 65092B (2007) https://doi.org/10.1117/12.708180

KEYWORDS: X-rays, X-ray imaging, Fluoroscopy, Image registration, X-ray computed tomography, Visualization, Electrophysiology, Data modeling, 3D image processing, Radiography

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Proceedings Article | 21 March 2007 Paper

Rotational x-ray angiography: a method for intra-operative volume imaging of the left-atrium and pulmonary veins for atrial fibrillation ablation guidance

R. Manzke, L. Zagorchev, A. d'Avila, A. Thiagalingam, V. Reddy, R. Chan

Proceedings Volume 6509, 65090T (2007) https://doi.org/10.1117/12.708485

KEYWORDS: Image segmentation, Heart, Atrial fibrillation, Data modeling, Magnetic resonance imaging, 3D modeling, X-ray imaging, Veins, Data acquisition, 3D acquisition

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Proceedings Article | 21 March 2007 Paper

Multimodality image guidance system integrating x-ray fluoroscopy and ultrasound image streams with electromagnetic tracking

Luis Gutiérrez, Guy Shechter, Douglas Stanton, Sandeep Dalal, Daniel Elgort, Robert Manzke, Raymond Chan, Lyubomir Zagorchev

Proceedings Volume 6509, 65090K (2007) https://doi.org/10.1117/12.711527

KEYWORDS: X-rays, Ultrasonography, X-ray imaging, Imaging systems, Image registration, Electromagnetism, Computer programming, Sensors, 3D acquisition, 3D modeling

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Proceedings Article | 21 March 2007 Paper

Intraprocedural fusion of electroanatomical maps (EAM) with imaging data based on rapidly-sampled volumetric point clouds from continuous EAM catheter tracking

R. Chan, Z. Malchano, R. Vijaykumar, R. Manzke, L. Zagorchev, V. Reddy

Proceedings Volume 6509, 65090R (2007) https://doi.org/10.1117/12.709607

KEYWORDS: Image registration, Associative arrays, Image segmentation, Clouds, Imaging systems, Data fusion, Atrial fibrillation, Error analysis, Heart, Magnetic resonance imaging

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Image-guided therapy for electrophysiology applications requires integration of pre-procedural volumetric imaging data with intra-procedural electroanatomical mapping (EAM) information. Existing methods for fusion of EAM and imaging data are based on fiducial landmark identification or point-to-surface distance minimization algorithms, both of which require detailed EAM mapping. This mapping procedure requires specific selection of points on the endocardial surface and this point acquisition process is skill-dependent, time-consuming and labor-intensive. The mapping catheter tip must first be navigated to a landmark on the endocardium, tip contact must be verified, and finally the tip location must be explicitly annotated within the EAM data record. This process of individual landmark identification and annotation must be repeated carefully >50 times to define endocardial and other vascular surfaces with sufficient detail for iterated-closest-point (ICP)-based registration. To achieve this, 30-45 minutes of mapping just for the registration procedure can be necessary before the interventional component of the patient study begins. Any acquired EAM point location that is not in contact with the chamber surface can adversely impact the quality of registration. Significantly faster point acquisition can be achieved by recording catheter tip locations automatically and continuously without requiring explicit navigation to and annotation of fiducial landmarks. We present a novel registration framework in which EAM locations are rapidly acquired and recorded in a continuous, untriggered fashion while the electrophysiologist manipulates the catheter tip within the heart. Results from simulation indicate that mean registration errors are on the order of 3-4mm, comparable in magnitude to conventional registration procedures which take significantly longer to perform. Qualitative assessment in clinical data also reflects good agreement with physician expectations.

Proceedings Article | 13 March 2006 Paper

Integration of real-time x-ray fluoroscopy, rotational x-ray imaging, and real-time catheter tracking for improved navigation in interventional cardiac electrophysiology procedures

R. Manzke, R. Chan, G. Shechter, S. Sokka, D. Stanton, Z. Malchano, V. Rasche, V. Reddy

Proceedings Volume 6141, 614112 (2006) https://doi.org/10.1117/12.651715

KEYWORDS: X-rays, X-ray imaging, 3D image processing, Visualization, Fluoroscopy, 3D acquisition, Data acquisition, Electrophysiology, Sensors, Image registration

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Proceedings Article | 10 March 2006 Paper

Non-rigid registration for fusion of carotid vascular ultrasound and MRI volumetric datasets

R. Chan, S. Sokka, D. Hinton, R. Manzke, A. Hanekamp, V. Reddy, M. Kaazempur-Mofrad, V. Rasche

Proceedings Volume 6144, 61442E (2006) https://doi.org/10.1117/12.651786

KEYWORDS: Magnetic resonance imaging, Ultrasonography, Image registration, Arteries, 3D image processing, Imaging systems, Tissues, Spatial resolution, Transducers, Image segmentation

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Proceedings Article | 7 March 2006 Paper

Retinal nerve fiber layer thickness map

Mircea Mujat, Raymond Chan, Barry Cense, Hyle Park, Chulmin Joo, Teresa Chen, Johannes de Boer

Proceedings Volume 6138, 61380J (2006) https://doi.org/10.1117/12.649064

KEYWORDS: Optical coherence tomography, Reflectivity, Nerve, Image processing, Blood vessels, Binary data, Retina, Tissue optics, Edge detection, Biomedical optics

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Proceedings Article | 20 February 2006 Paper

Retinal nerve fiber layer thickness map and blood flow pulsation measured with SDOCT

Mircea Mujat, Raymond Chan, Barry Cense, Mark Pierce, Hyle Park, Chulmin Joo, Teresa Chen, Johannes de Boer

Proceedings Volume 6079, 607909 (2006) https://doi.org/10.1117/12.649095

KEYWORDS: Optical coherence tomography, Blood circulation, Reflectivity, Blood vessels, Nerve, Arteries, Veins, Doppler effect, Doppler tomography, Phase shifts

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Proceedings Article | 4 August 2000 Paper

Ultrasound analysis of vascular structure and deformation

Ray Chan, John Kaufhold, Robert Lees, William Karl

Proceedings Volume 4037, (2000) https://doi.org/10.1117/12.395046

KEYWORDS: Tissues, Ultrasonography, Image processing, Arteries, Motion estimation, Finite element methods, Optical flow, Injuries, Blood pressure, Matrices

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Proceedings Article | 13 July 1999 Paper

Ultrasound tissue analysis and characterization

John Kaufhold, Ray Chan, William Karl, David Castanon

Proceedings Volume 3712, (1999) https://doi.org/10.1117/12.353013

KEYWORDS: Ultrasonography, Image processing, Tissues, Biomedical optics, Image segmentation, Image enhancement, Speckle, Medical imaging, Matrices, Image quality

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Showing 5 of 15 publications

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