Patrick Wolf | Duke University (original) (raw)

Papers by Patrick Wolf

Research paper thumbnail of Substantial reduction in defibrillation thresholds in dogs using a one capacitor dual biphasic waveform and multielectrode nonthoracotomy lead configurations

Journal of the American College of Cardiology, 1991

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Research paper thumbnail of We need to go beyond ideological positions and find out what actually works for children. If something works for children, let's do it." Secretary of Education Arne Duncan

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Research paper thumbnail of Introduction to the Special section

ACM Transactions on Asian Language Information Processing, 2006

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Research paper thumbnail of Real-Time 3D Intracranial Ultrasound

We have described and fabricated 2D array transducers for many real-time volumetric imaging appli... more We have described and fabricated 2D array transducers for many real-time volumetric imaging applications. These applications include transducers operating up to 7 MHz for transthoracic imaging, up to 15 MHz for intracardiac echocardiography (ICE), 5 MHz for transesophageal echocardiography (TEE) and 7 MHz for laparoscopic ultrasound imaging (LUS). A transducer originally designed for TEE was recently adapted for real time volumetric endoscopic imaging of the brain. The transducer consists of a 36 x 36 array with an interelement spacing of 0.18 mm. There are 504 transmitting and 252 receive channels placed in a regular pattern in the array. The operating frequency is 4.5 MHz with a –6 dB bandwidth of 30%. The transducer is fabricated on a 10 layer flexible circuit from MicroConnex (Snoqualmie, WA). The Volumetrics Medical Imaging (Durham, NC) 3D scanner was used to obtain images in a canine model. A transcalvarial acoustic window was created under general anesthesia in the animal lab...

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Research paper thumbnail of Integrated circuit amplifiers for multi-electrode intracortical recording

Journal of Neural Engineering, 2009

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Research paper thumbnail of Excitation properties of the right cervical vagus nerve in adult dogs

Experimental Neurology, 2011

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Research paper thumbnail of Feasibility of Near Real-Time Lesion Assessment During Radiofrequency Catheter Ablation in Humans Using Acoustic Radiation Force Impulse Imaging

Background: Visual confirmation of radiofrequency ablation (RFA) lesions during clinical cardiac ... more Background: Visual confirmation of radiofrequency ablation (RFA) lesions during clinical cardiac ablation procedures could improve procedure efficacy, safety, and efficiency. It was previously shown that acoustic radiation force impulse (ARFI) imaging can identify RFA lesions in vitro and in vivo in an animal model. This is the " first-inhuman " feasibility demonstration of intracardiac ARFI imaging of RFA lesions in patients undergoing catheter ablation for atrial flutter (AFL) or atrial fibrillation (AF). Methods and Results: Patients scheduled for right atrial (RA) ablation for AFL or left atrial (LA) ablation for drug refractory AF were eligible for imaging. Diastole-gated intracardiac ARFI images were acquired using one of two equipment configurations: (1) a Siemens ACUSON S2000 TM ultrasound scanner and 8/10Fr AcuNav TM ultrasound catheter, or (2) a CARTO 3 TM integrated Siemens SC2000 TM and 10Fr SoundStar TM ultrasound catheter. A total of 11 patients (AFL = 3; AF = 8) were imaged. ARFI images were acquired of ablation target regions, including the RA cavotricuspid isthmus (CTI), and the LA roof, pulmonary vein ostia, posterior wall, posterior mitral valve annulus, and the ridge between the pulmonary vein and LA appendage. ARFI images revealed increased relative myocardial stiffness at ablation catheter contact sites after RFA and at anatomical mapping-tagged RFA treatment sites. Conclusions: ARFI images from a pilot group of patients undergoing catheter ablation for AFL and AF demonstrate the ability of this technique to identify intra-procedure RFA lesion formation. The results encourage further refinement of ARFI imaging clinical tools and continued investigation in larger clinical trials. (J Cardiovasc Electrophysiol, Vol. pp. 1-9) acoustic radiation force impulse imaging, atrial fibrillation, atrial flutter, electroanatomical mapping, intracardiac echocardiography, lesion assessment, transcatheter radiofrequency ablation

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Research paper thumbnail of Intracardiac acoustic radiation force impulse imaging: A novel imaging method for intraprocedural evaluation of radiofrequency ablation lesions

Heart Rhythm, Nov 2012

Background: Arrhythmia recurrence after cardiac radiofrequency ablation (RFA) for atrial fibrilla... more Background: Arrhythmia recurrence after cardiac radiofrequency ablation (RFA) for atrial fibrillation has been linked to conduction through discontinuous lesion lines. Intraprocedural visualization and corrective ablation of lesion line discontinuities could decrease postprocedure atrial fibrillation recurrence. Intracardiac acoustic radiation force impulse (ARFI) imaging is a new imaging technique that visualizes RFA lesions by mapping the relative elasticity contrast between compliant-unablated and stiff RFA-treated myocardium.

Objective: To determine whether intraprocedure ARFI images can identify RFA-treated myocardium in vivo.

Methods: In 8 canines, an electroanatomical mapping–guided intracardiac echo catheter was used to acquire 2-dimensional ARFI images along right atrial ablation lines before and after RFA. ARFI images were acquired during diastole with the myocardium positioned at the ARFI focus (1.5 cm) and parallel to the intracardiac echo transducer for maximal and uniform energy delivery to the tissue. Three reviewers categorized each ARFI image as depicting no lesion, noncontiguous lesion, or contiguous lesion. For comparison, 3 separate reviewers confirmed RFA lesion presence and contiguity on the basis of functional conduction block at the imaging plane location on electroanatomical mapping activation maps.

Results: Ten percent of ARFI images were discarded because of motion artifacts. Reviewers of the ARFI images detected RFA-treated sites with high sensitivity (95.7%) and specificity (91.5%). Reviewer identification of contiguous lesions had 75.3% specificity and 47.1% sensitivity.

Conclusions: Intracardiac ARFI imaging was successful in identifying endocardial RFA treatment when specific imaging conditions were maintained. Further advances in ARFI imaging technology would facilitate a wider range of imaging opportunities for clinical lesion evaluation.

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Research paper thumbnail of Near real time evaluation of cardiac radiofrequency ablation lesions with intracardiac echocardiography based acoustic radiation force impulse imaging.

The Journal of the …, Jan 1, 2011

[Cardiac radiofrequency (rf) ablation is used to treat cardiac arrhythmias. Multiple rf lesions a... more [Cardiac radiofrequency (rf) ablation is used to treat cardiac arrhythmias. Multiple rf lesions are created to form lines of electrical block to disrupt arrhythmic wavefronts. However, image based lesion evaluation is not performed and clinicians rely on changes in electrical propagation to evaluate lesion quality. A near real time lesion evaluation system was developed and tested in vitro and in canines using acoustic radiation force impulse imaging (ARFIi) combined with a catheter tracking system (CARTO, Biosense Webster). rf ablation ...

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Research paper thumbnail of Intracardiac measurements of elasticity using Acoustic Radiation Force Impulse (ARFI) methods: Temporal and spatial stability of shear wave velocimetry

… (IUS), Jan 1, 2010

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Research paper thumbnail of Intracardiac acoustic radiation force impulse imaging: A novel imaging method for intraprocedural evaluation of radiofrequency ablation lesions

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Research paper thumbnail of Intracardiac Acoustic Radiation Force Impulse (ARFI) and Shear Wave Imaging in Pigs With Focal Infarctions

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Research paper thumbnail of Direct in vivo myocardial infarct visualization using 3D ultrasound and passive strain contrast

I. INTRODUCTION In contrast to traditional methods of myocardial elastography that image active c... more I. INTRODUCTION In contrast to traditional methods of myocardial elastography that image active cardiac contraction [1], a passive alternative for inducing contrast in the myocardium is introduced. The proposed approach uses a passive “external” force to induce contrast. It will be shown that this force can be applied non-invasively by using a physiological stimulus— atrial contraction. Atrial contraction results in an additional bolus of blood injected into the ventricles during the period of atrial systole. The contrast in this new method comes from differences ...

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Research paper thumbnail of Radiofrequency Ablation Lesions Contrast in Intracardiac Acoustic Radiation Force Impulse Images of

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Research paper thumbnail of Parametric pressure-volume analysis and acoustic radiation force impulse imaging of left ventricular function

… (IUS), Jan 1, 2010

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Research paper thumbnail of The Evolution of Tissue Stiffness at Radiofrequency Ablation Sites during Lesion Formation and in the Peri-Ablation Period

Journal of cardiovascular electrophysiology, Jan 12, 2015

Elastography imaging can provide radiofrequency ablation (RFA) lesion assessment due to tissue st... more Elastography imaging can provide radiofrequency ablation (RFA) lesion assessment due to tissue stiffening at the ablation site. An important aspect of assessment is the spatial and temporal stability of the region of stiffness increase in the peri-ablation period. The aim of this study was to use two ultrasound-based elastography techniques, shear wave elasticity imaging (SWEI) and acoustic radiation force impulse (ARFI) imaging to monitor the evolution of tissue stiffness at ablation sites in the 30 minutes following lesion creation. In 6 canine subjects, SWEI measurements and 2-D ARFI images were acquired at six ventricular endocardial RFA sites before, during, and for 30 minutes post ablation. An immediate increase in tissue stiffness was detected during RFA, and the area of the post-ablation region of stiffness increase (RoSI) as well as the relative stiffness at the RoSI center were stable approximately 2 minutes after ablation. Of note is the observation that relative stiffnes...

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Research paper thumbnail of The feasibility of myocardial infarct visualization using atrial kick induced strain (AKIS) contrast

Ultrasound in medicine & biology, 2014

The most common mechanical measure of the heart integrates ventricular strain between end-diastol... more The most common mechanical measure of the heart integrates ventricular strain between end-diastole and end-systole in order to provide a measure of contraction. Here an approach is described for estimating a correlate to local passive mechanical properties. Passive strain is measured by estimating ventricular strain during atrial systole. During atrial systole the atria contract causing passive stretching in the ventricles from increased volume. This modification to traditional cardiac strain is here termed atrial kick induced strain (AKIS) imaging. AKIS imaging was evaluated in a canine ablation model of chronic infarct and a canine true chronic infarct model. AKIS images of ablation lesions were compared against acoustic radiation force impulse (ARFI) images and tissue blanching, and true chronic infarct AKIS images were compared against delayed enhanced-contrast magnetic resonance. AKIS images were made with 2-D and 3-D ultrasound data. In both studies, AKIS images and the compar...

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Research paper thumbnail of Design Methodology and CAD Tools for Prototyping Delta-Sigma Fractional-N Frequency Synthesizers

18th IEEE/IFIP International Workshop on Rapid System Prototyping (RSP '07), 2007

... Fractional-N Frequency Synthesizers Himanshu Arora Marvell Semiconductor Santa Clara Californ... more ... Fractional-N Frequency Synthesizers Himanshu Arora Marvell Semiconductor Santa Clara California, USA ha@ee.duke.edu Nikolaus Klemmer Ericsson Mobile Platforms Research Triangle Park Durham, NC nikolaus.klemmer@ericsson.com ...

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Research paper thumbnail of Phase-Noise Driven System Design of Fractional-N Frequency Synthesizers and Validation With Measured Results

IEEE Computer Society Annual Symposium on VLSI (ISVLSI '07), 2007

... Validation With Measured Results Himanshu Arora Marvell Semiconductor Santa Clara California,... more ... Validation With Measured Results Himanshu Arora Marvell Semiconductor Santa Clara California, USA ha@ee.duke.edu Nikolaus Klemmer Ericsson Mobile Platforms Research Triangle Park Durham, NC nikolaus.klemmer@ericsson.com ...

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Research paper thumbnail of Double Ring Array Catheter for In Vivo Real-Time 3D Ultrasound

Ultrasonic imaging, Jan 12, 2014

We developed new forward-viewing matrix transducers consisting of double ring arrays of 118 total... more We developed new forward-viewing matrix transducers consisting of double ring arrays of 118 total PZT elements integrated into catheters used to deploy medical interventional devices. Our goal is 3D ultrasound guidance of medical device implantation to reduce x-ray fluoroscopy exposure. The double ring arrays were fabricated on inner and outer custom polyimide flexible circuits with inter-element spacing of 0.20 mm and then wrapped around an 11 French (Fr) catheter to produce a 15 Fr catheter (outer diameter [O.D.]). We used a braided cabling technology to connect the elements to the Volumetrics Medical Imaging (VMI) real-time 3D ultrasound scanner. Transducer performance yielded an average -6 dB fractional bandwidth of 49% ± 11% centered at 4.4 MHz for 118 elements. Real-time 3D cardiac scans of the in vivo pig model yielded good image quality including en face views of the tricuspid valve and real-time 3D guidance of an endo-myocardial biopsy catheter introduced into the left vent...

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Research paper thumbnail of Substantial reduction in defibrillation thresholds in dogs using a one capacitor dual biphasic waveform and multielectrode nonthoracotomy lead configurations

Journal of the American College of Cardiology, 1991

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Research paper thumbnail of We need to go beyond ideological positions and find out what actually works for children. If something works for children, let's do it." Secretary of Education Arne Duncan

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Research paper thumbnail of Introduction to the Special section

ACM Transactions on Asian Language Information Processing, 2006

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Research paper thumbnail of Real-Time 3D Intracranial Ultrasound

We have described and fabricated 2D array transducers for many real-time volumetric imaging appli... more We have described and fabricated 2D array transducers for many real-time volumetric imaging applications. These applications include transducers operating up to 7 MHz for transthoracic imaging, up to 15 MHz for intracardiac echocardiography (ICE), 5 MHz for transesophageal echocardiography (TEE) and 7 MHz for laparoscopic ultrasound imaging (LUS). A transducer originally designed for TEE was recently adapted for real time volumetric endoscopic imaging of the brain. The transducer consists of a 36 x 36 array with an interelement spacing of 0.18 mm. There are 504 transmitting and 252 receive channels placed in a regular pattern in the array. The operating frequency is 4.5 MHz with a –6 dB bandwidth of 30%. The transducer is fabricated on a 10 layer flexible circuit from MicroConnex (Snoqualmie, WA). The Volumetrics Medical Imaging (Durham, NC) 3D scanner was used to obtain images in a canine model. A transcalvarial acoustic window was created under general anesthesia in the animal lab...

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Research paper thumbnail of Integrated circuit amplifiers for multi-electrode intracortical recording

Journal of Neural Engineering, 2009

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Research paper thumbnail of Excitation properties of the right cervical vagus nerve in adult dogs

Experimental Neurology, 2011

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Research paper thumbnail of Feasibility of Near Real-Time Lesion Assessment During Radiofrequency Catheter Ablation in Humans Using Acoustic Radiation Force Impulse Imaging

Background: Visual confirmation of radiofrequency ablation (RFA) lesions during clinical cardiac ... more Background: Visual confirmation of radiofrequency ablation (RFA) lesions during clinical cardiac ablation procedures could improve procedure efficacy, safety, and efficiency. It was previously shown that acoustic radiation force impulse (ARFI) imaging can identify RFA lesions in vitro and in vivo in an animal model. This is the " first-inhuman " feasibility demonstration of intracardiac ARFI imaging of RFA lesions in patients undergoing catheter ablation for atrial flutter (AFL) or atrial fibrillation (AF). Methods and Results: Patients scheduled for right atrial (RA) ablation for AFL or left atrial (LA) ablation for drug refractory AF were eligible for imaging. Diastole-gated intracardiac ARFI images were acquired using one of two equipment configurations: (1) a Siemens ACUSON S2000 TM ultrasound scanner and 8/10Fr AcuNav TM ultrasound catheter, or (2) a CARTO 3 TM integrated Siemens SC2000 TM and 10Fr SoundStar TM ultrasound catheter. A total of 11 patients (AFL = 3; AF = 8) were imaged. ARFI images were acquired of ablation target regions, including the RA cavotricuspid isthmus (CTI), and the LA roof, pulmonary vein ostia, posterior wall, posterior mitral valve annulus, and the ridge between the pulmonary vein and LA appendage. ARFI images revealed increased relative myocardial stiffness at ablation catheter contact sites after RFA and at anatomical mapping-tagged RFA treatment sites. Conclusions: ARFI images from a pilot group of patients undergoing catheter ablation for AFL and AF demonstrate the ability of this technique to identify intra-procedure RFA lesion formation. The results encourage further refinement of ARFI imaging clinical tools and continued investigation in larger clinical trials. (J Cardiovasc Electrophysiol, Vol. pp. 1-9) acoustic radiation force impulse imaging, atrial fibrillation, atrial flutter, electroanatomical mapping, intracardiac echocardiography, lesion assessment, transcatheter radiofrequency ablation

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Research paper thumbnail of Intracardiac acoustic radiation force impulse imaging: A novel imaging method for intraprocedural evaluation of radiofrequency ablation lesions

Heart Rhythm, Nov 2012

Background: Arrhythmia recurrence after cardiac radiofrequency ablation (RFA) for atrial fibrilla... more Background: Arrhythmia recurrence after cardiac radiofrequency ablation (RFA) for atrial fibrillation has been linked to conduction through discontinuous lesion lines. Intraprocedural visualization and corrective ablation of lesion line discontinuities could decrease postprocedure atrial fibrillation recurrence. Intracardiac acoustic radiation force impulse (ARFI) imaging is a new imaging technique that visualizes RFA lesions by mapping the relative elasticity contrast between compliant-unablated and stiff RFA-treated myocardium.

Objective: To determine whether intraprocedure ARFI images can identify RFA-treated myocardium in vivo.

Methods: In 8 canines, an electroanatomical mapping–guided intracardiac echo catheter was used to acquire 2-dimensional ARFI images along right atrial ablation lines before and after RFA. ARFI images were acquired during diastole with the myocardium positioned at the ARFI focus (1.5 cm) and parallel to the intracardiac echo transducer for maximal and uniform energy delivery to the tissue. Three reviewers categorized each ARFI image as depicting no lesion, noncontiguous lesion, or contiguous lesion. For comparison, 3 separate reviewers confirmed RFA lesion presence and contiguity on the basis of functional conduction block at the imaging plane location on electroanatomical mapping activation maps.

Results: Ten percent of ARFI images were discarded because of motion artifacts. Reviewers of the ARFI images detected RFA-treated sites with high sensitivity (95.7%) and specificity (91.5%). Reviewer identification of contiguous lesions had 75.3% specificity and 47.1% sensitivity.

Conclusions: Intracardiac ARFI imaging was successful in identifying endocardial RFA treatment when specific imaging conditions were maintained. Further advances in ARFI imaging technology would facilitate a wider range of imaging opportunities for clinical lesion evaluation.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Near real time evaluation of cardiac radiofrequency ablation lesions with intracardiac echocardiography based acoustic radiation force impulse imaging.

The Journal of the …, Jan 1, 2011

[Cardiac radiofrequency (rf) ablation is used to treat cardiac arrhythmias. Multiple rf lesions a... more [Cardiac radiofrequency (rf) ablation is used to treat cardiac arrhythmias. Multiple rf lesions are created to form lines of electrical block to disrupt arrhythmic wavefronts. However, image based lesion evaluation is not performed and clinicians rely on changes in electrical propagation to evaluate lesion quality. A near real time lesion evaluation system was developed and tested in vitro and in canines using acoustic radiation force impulse imaging (ARFIi) combined with a catheter tracking system (CARTO, Biosense Webster). rf ablation ...

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Research paper thumbnail of Intracardiac measurements of elasticity using Acoustic Radiation Force Impulse (ARFI) methods: Temporal and spatial stability of shear wave velocimetry

… (IUS), Jan 1, 2010

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Research paper thumbnail of Intracardiac acoustic radiation force impulse imaging: A novel imaging method for intraprocedural evaluation of radiofrequency ablation lesions

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Intracardiac Acoustic Radiation Force Impulse (ARFI) and Shear Wave Imaging in Pigs With Focal Infarctions

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Direct in vivo myocardial infarct visualization using 3D ultrasound and passive strain contrast

I. INTRODUCTION In contrast to traditional methods of myocardial elastography that image active c... more I. INTRODUCTION In contrast to traditional methods of myocardial elastography that image active cardiac contraction [1], a passive alternative for inducing contrast in the myocardium is introduced. The proposed approach uses a passive “external” force to induce contrast. It will be shown that this force can be applied non-invasively by using a physiological stimulus— atrial contraction. Atrial contraction results in an additional bolus of blood injected into the ventricles during the period of atrial systole. The contrast in this new method comes from differences ...

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Research paper thumbnail of Radiofrequency Ablation Lesions Contrast in Intracardiac Acoustic Radiation Force Impulse Images of

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Parametric pressure-volume analysis and acoustic radiation force impulse imaging of left ventricular function

… (IUS), Jan 1, 2010

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Research paper thumbnail of The Evolution of Tissue Stiffness at Radiofrequency Ablation Sites during Lesion Formation and in the Peri-Ablation Period

Journal of cardiovascular electrophysiology, Jan 12, 2015

Elastography imaging can provide radiofrequency ablation (RFA) lesion assessment due to tissue st... more Elastography imaging can provide radiofrequency ablation (RFA) lesion assessment due to tissue stiffening at the ablation site. An important aspect of assessment is the spatial and temporal stability of the region of stiffness increase in the peri-ablation period. The aim of this study was to use two ultrasound-based elastography techniques, shear wave elasticity imaging (SWEI) and acoustic radiation force impulse (ARFI) imaging to monitor the evolution of tissue stiffness at ablation sites in the 30 minutes following lesion creation. In 6 canine subjects, SWEI measurements and 2-D ARFI images were acquired at six ventricular endocardial RFA sites before, during, and for 30 minutes post ablation. An immediate increase in tissue stiffness was detected during RFA, and the area of the post-ablation region of stiffness increase (RoSI) as well as the relative stiffness at the RoSI center were stable approximately 2 minutes after ablation. Of note is the observation that relative stiffnes...

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Research paper thumbnail of The feasibility of myocardial infarct visualization using atrial kick induced strain (AKIS) contrast

Ultrasound in medicine & biology, 2014

The most common mechanical measure of the heart integrates ventricular strain between end-diastol... more The most common mechanical measure of the heart integrates ventricular strain between end-diastole and end-systole in order to provide a measure of contraction. Here an approach is described for estimating a correlate to local passive mechanical properties. Passive strain is measured by estimating ventricular strain during atrial systole. During atrial systole the atria contract causing passive stretching in the ventricles from increased volume. This modification to traditional cardiac strain is here termed atrial kick induced strain (AKIS) imaging. AKIS imaging was evaluated in a canine ablation model of chronic infarct and a canine true chronic infarct model. AKIS images of ablation lesions were compared against acoustic radiation force impulse (ARFI) images and tissue blanching, and true chronic infarct AKIS images were compared against delayed enhanced-contrast magnetic resonance. AKIS images were made with 2-D and 3-D ultrasound data. In both studies, AKIS images and the compar...

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Research paper thumbnail of Design Methodology and CAD Tools for Prototyping Delta-Sigma Fractional-N Frequency Synthesizers

18th IEEE/IFIP International Workshop on Rapid System Prototyping (RSP '07), 2007

... Fractional-N Frequency Synthesizers Himanshu Arora Marvell Semiconductor Santa Clara Californ... more ... Fractional-N Frequency Synthesizers Himanshu Arora Marvell Semiconductor Santa Clara California, USA ha@ee.duke.edu Nikolaus Klemmer Ericsson Mobile Platforms Research Triangle Park Durham, NC nikolaus.klemmer@ericsson.com ...

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Research paper thumbnail of Phase-Noise Driven System Design of Fractional-N Frequency Synthesizers and Validation With Measured Results

IEEE Computer Society Annual Symposium on VLSI (ISVLSI '07), 2007

... Validation With Measured Results Himanshu Arora Marvell Semiconductor Santa Clara California,... more ... Validation With Measured Results Himanshu Arora Marvell Semiconductor Santa Clara California, USA ha@ee.duke.edu Nikolaus Klemmer Ericsson Mobile Platforms Research Triangle Park Durham, NC nikolaus.klemmer@ericsson.com ...

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Research paper thumbnail of Double Ring Array Catheter for In Vivo Real-Time 3D Ultrasound

Ultrasonic imaging, Jan 12, 2014

We developed new forward-viewing matrix transducers consisting of double ring arrays of 118 total... more We developed new forward-viewing matrix transducers consisting of double ring arrays of 118 total PZT elements integrated into catheters used to deploy medical interventional devices. Our goal is 3D ultrasound guidance of medical device implantation to reduce x-ray fluoroscopy exposure. The double ring arrays were fabricated on inner and outer custom polyimide flexible circuits with inter-element spacing of 0.20 mm and then wrapped around an 11 French (Fr) catheter to produce a 15 Fr catheter (outer diameter [O.D.]). We used a braided cabling technology to connect the elements to the Volumetrics Medical Imaging (VMI) real-time 3D ultrasound scanner. Transducer performance yielded an average -6 dB fractional bandwidth of 49% ± 11% centered at 4.4 MHz for 118 elements. Real-time 3D cardiac scans of the in vivo pig model yielded good image quality including en face views of the tricuspid valve and real-time 3D guidance of an endo-myocardial biopsy catheter introduced into the left vent...

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Research paper thumbnail of Visualization of Convective Heat Transfer with a Thermal Camera in vivo during Cardiac Radiofrequency Ablation

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Research paper thumbnail of Feasibility of using a generalized-Gaussian Markov random field prior for Bayesian speckle tracking of small displacements

2014 IEEE International Ultrasonics Symposium, 2014

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