Bio

Clinical Focus


  • Consultative Medicine
  • Athletic Health
  • Internal Medicine
  • Chronic Care Management
  • Preventive Health
  • Syncope

Academic Appointments


Professional Education


  • Residency:Tufts-New England Medical Center (2005) MA
  • Fellowship:Stanford University Medical Center (2008) CA
  • Fellowship, Stanford University, Biodesign (2006)
  • Board Certification: Internal Medicine, American Board of Internal Medicine (2005)
  • Internship:Tufts-New England Medical Center (2003) MA
  • Medical Education:Tufts University (2002) MA
  • MEng, MIT, EECS (1997)
  • SB, MIT, EECS (1996)

Research & Scholarship

Current Research and Scholarly Interests


Medical device design, prototyping and testing.

Publications

Journal Articles


  • Visualizing ablation gaps in vitro using a deflectable fiber optic endocardial visualization catheter JOURNAL OF INTERVENTIONAL CARDIAC ELECTROPHYSIOLOGY Irani, A. R., Lin, B., Eversull, C., Hsia, H. H., Zei, P. C., Wang, P. J., Al-Ahmad, A. 2009; 25 (2): 107-110

    Abstract

    The efficacy of pulmonary vein isolation for the treatment of atrial fibrillation may be limited by the ability to make continuous and transmural lesions utilizing an ablation catheter. Gaps often persist between ablation lesions leading to failed electrical isolation and thus failed ablation. Recently, a deflectable fiberoptic endocardial visualization catheter has been introduced for use in imaging the coronary sinus using light in the visible spectrum. We utilize this catheter to visualize the endocardial surface and examine radiofrequency ablation lesions in porcine endocardium to determine the presence of gaps between radiofrequency lesions.Videos were taken of the lesions and shown to two readers who were asked to identify the gaps ranging from less than 0.1 mm-9.8 mm.Ninety-four lesion gaps were reviewed. The readers demonstrated a combined accuracy of 98.4% at identifying gaps.Gaps between ablation lesions can be accurately identified down to less than 1 mm distances in vitro using a direct visualization catheter. Further studies are warranted to confirm these finding in vivo.

    View details for DOI 10.1007/s10840-008-9338-7

    View details for Web of Science ID 000267683500004

    View details for PubMedID 19148727

  • Direct Visualization of Cardiac Radiofrequency Ablation Lesions JOURNAL OF CARDIOVASCULAR TRANSLATIONAL RESEARCH Eversull, C. S., Lin, B., Irani, A. R., Quigley, M. L., Mourlas, N. J., Hsia, H. H., Zei, P. C., Al-Ahmad, A., Wang, P. J. 2009; 2 (2): 198-201

    Abstract

    Effective ablation of atrial fibrillation and other cardiac arrhythmias requires precise catheter navigation and controlled delivery of energy to cardiac tissue. In this study, we summarize our initial experience using a fiber optic direct visualization catheter to evaluate and guide placement of endocardial radiofrequency (RF) ablation lesions. RF lesions were created in cadaveric porcine hearts and examined in a blood-filled field using a direct visualization catheter. Direct visualization of RF lesions was repeated in vivo using an ovine model. Lesions and interlesion gaps were clearly identifiable using the direct visualization catheter. It was possible to place lesions in proximity to anatomical landmarks and in relation to one another. Catheter-generated images correlated well with lesion appearance on gross examination. Direct catheter-based visualization is a feasible technique for guiding RF lesion placement, estimating lesion size, and identifying interlesion gaps. Future work is needed to correlate surface appearance with transmurality and electrical isolation.

    View details for DOI 10.1007/s12265-009-9094-9

    View details for Web of Science ID 000284690100010

    View details for PubMedID 20559988

  • A Covariance-Based Algorithm: A Novel Technique for Rhythm Discrimination in ICDs 2008 30TH ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY, VOLS 1-8 Kamousi, B., Lin, B., Al-Ahmad, A., Hsia, H., Zei, P., Natale, A., Moss, A., Daubert, J., Zareba, W., Wang, P. 2008: 5478-5481

    Abstract

    Inappropriate shocks due to misclassification of supraventricular and ventricular arrhythmias remain a major problem in the care of patients with Implantable Cardioverter defibrillators (ICDs). In this study we have investigated the ability of a new covariance-based algorithm, to distinguish Ventricular Tachycardia from other rhythms such as Supraventricular Tachycardia. The proposed algorithm has a low computational demand and with a small adjustment is applicable on both single-chamber and dual-chamber ICDs. The results are promising and suggest that the new covariance-based algorithm may be an effective method for ICD rhythm classification and may decrease inappropriate shocks.

    View details for Web of Science ID 000262404503170

    View details for PubMedID 19163957

  • Feasibility Testing of Novel Ablation Catheter-based Temperature Measurement Device Cardiostim 2008 Bryant Lin MD, Ronald Lo MD, Z Cheng MD, Manuela Kuehnel, Peter van der Sluis, Henry H. Hsia MD, Paul C. Zei MD PhD Paul J Wang MD, Amin Al-Ahmad MD 2008
  • Novel Method to Assess Gap Distance Between Ablation Lesions Featured Poster Heart Rhythm Society Lin BY, Eversull C, Chen H, Hsia H, Al-Ahmad A 2006
  • Extraction of buried P waves from printed electrocardiograms ANNALS OF NONINVASIVE ELECTROCARDIOLOGY Lin, B., Wang, P. J., Mahapatra, S., Homoud, M., Link, M., Estes, N. A., Al-Ahmad, A. 2005; 10 (2): 142-145

    Abstract

    Morphologic identification of ectopic P-waves from surface ECGs can be challenging, particularly when the P-wave is buried in the QRST wave complex. Because ECGs are often available on paper and not digitally, we developed a method of subtracting the T-wave from the buried P-wave complex on paper ECGs.To validate our system, an atrial extrastimulus was introduced during and following the T-wave. The ECGs were scanned and then transformed from an image format to a digital format. A computer algorithm digitally subtracted a QRST with no buried P-wave from one with a buried P-wave, thus resulting in an extracted P-wave. The extracted P-waves were compared to the nonburied P-wave by determining correlation coefficients and by visual grading by two independent reviewers.Visual grading comparing the buried P-wave with the exposed paced P-wave was 94%. The median correlation coefficient was 85%.An ectopic atrial P-wave obscured by a coincident QRST wave complex can be accurately derived from printed ECG using this PC-based system. Addition of this technique to the existing methods may aid in the localization and ablation of ectopic atrial foci.

    View details for Web of Science ID 000228826100004

    View details for PubMedID 15842425

  • Contractile actin expression in torn human menisci WOUND REPAIR AND REGENERATION Lin, B. Y., Richmond, J. C., Spector, M. 2002; 10 (4): 259-266

    Abstract

    The human meniscus is subject to injury that necessitates repair or removal. Many aspects of the cellular response to injury have not been well characterized. The purpose of this study was to describe the cellular distributions within the torn human meniscus. In addition to evaluating the cell density in selected regions, we investigated the cellular expression of a contractile actin isoform that has recently been found in the intact human meniscus. Included as a contemporaneous comparative group were torn human meniscal allografts. We hypothesized that a hypercellular surface zone would be found in the torn menisci, with a higher percentage of cells in this peripheral region expressing alpha-smooth muscle actin compared with other locations in the interior of the remnant. The rationale for this hypothesis was based on prior immunohistochemical investigations of the distribution of alpha-smooth muscle actin-containing cells in the torn human anterior cruciate ligament. Eighteen torn meniscal specimens were obtained from 17 patients, 0.5 to 84 months after injury, and four torn allograft meniscal samples were retrieved from three patients, 11 to 49 months after implantation. Microtomed sections of paraffin-embedded tissue were stained with hematoxylin and eosin and a monoclonal antibody to alpha-smooth muscle actin. The cell density and percentage of cells containing alpha-smooth muscle actin were determined in the following zones: synovial, vascular, hypercellular with loose collagen, hypocellular with dense collagen, and organized collagen. A cellular layer that resembled synovium was present on the surface of all but two of the specimens. Vascular regions were often continuous with the synovium abutting the more interior loose collagen zones. The total cell density was greatest in each of the zones closest to the periphery (synovium, vascular, and loose collagen; p < 0.001), when compared to the interior of the tissue. The synovium-like layer was found to have the highest percentage of alpha-smooth muscle actin-expressing cells and the highest alpha-smooth muscle actin-containing cell density (p < 0.05). Similar results were found for the torn allograft menisci. These findings confirm the working hypothesis and suggest that the torn human meniscus is capable of mounting a reparative response, including the proliferation of cells capable of contributing to wound closure. This underscores the importance of providing a bridging scaffold into which such cells can migrate.

    View details for Web of Science ID 000177543900010

    View details for PubMedID 12191009

  • Changes in Physical and Biochemical Properties of Cartilage in the Guinea Pig Spontaneous OA Model are Consistent with Hypertrophic Remodeling Transactions of the Orthopaedic Research Society Lin BY, Sebern EL, Frank EH, Dube N, Grodzinsky AJ 1998; 23: 130

Conference Proceedings


  • A New Approach for ICD Rhythm Classification based on Support Vector Machines Kamousi, B., Tewfik, A., Lin, B., Al-Ahmad, A., Hsia, H., Zei, P., Wang, P. IEEE. 2009: 2478-2481

    Abstract

    Inappropriate shocks due to misclassification of supraventricular and ventricular arrhythmias remain a major problem in the care of patients with Implantable Cardioverter Defibrillators (ICDs). The purpose of this study was to investigate the ability of a new covariance-based support vector machine classifier, to distinguish ventricular tachycardia from other rhythms such as supraventricular tachycardia. The proposed algorithm is applicable on both single and dual chamber ICDs and has a low computational demand. The results demonstrate that suggested algorithm has considerable promise and merits further investigation.

    View details for Web of Science ID 000280543601357

    View details for PubMedID 19964965

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