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Search Publications by: Tim Quinn (Fed)

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Displaying 1 - 25 of 36

Evaluation of 3D Curvature and Lead Stress of Transvenous Right Ventricular Leads: The Human Use Conditions Study (HUCS)

September 9, 2023
Author(s)
Jonathan Piccini, Tim Quinn, Lucas Koepke, James Dawson, Nicki Mara, Jason Santelli, Diane Muff, Jordan Savela, Alex Felber, Michael Friedrich, Jens Rump, Felix Tschentscher, Jake Benzing, Charles Swerdlow
Transvenous leads of cardiac implanted electronic device (CIED) systems are meant to last the life of the patient, but they are at risk for conductor fatigue fracture from applied alternating stress. This stress depends on lead design and use conditions

Multiple Changepoint Analysis of Noisy Nonlinear Data with an Application to Modeling Crack Growth in Additively Manufactured Titanium

December 5, 2019
Author(s)
Lucas N. Koepke, Jolene D. Splett, Timothy P. Quinn, Nikolas W. Hrabe, Jake T. Benzing, Michael R. Frey
Noisy measurement data pose a challenge for changepoint analysis, especially in the presence of multiple changepoints and when the model is nonlinear. We explore various approaches to estimating changepoints and their standard errors under these conditions

Hot isostatic pressing (HIP) to achieve isotropic microstructure and retain as-built strength in additive manufacturing titanium alloy (Ti-6Al-4V)

September 23, 2019
Author(s)
Jake T. Benzing, Nikolas W. Hrabe, Timothy P. Quinn, Ryan M. White, Ross A. Rentz, Magnus Ahlfors
Hot isostatic pressing (HIP) treatments are used to seal internal porosity because defects exist in as-built Ti-6Al-4V parts produced by electron beam melting powder bed fusion. Standard HIP treatment of Ti-6Al-4V parts reduces internal porosity but

The Reproducibility of a Proposed Standard Fatigue Test for Cardiac Device Leads

August 1, 2019
Author(s)
Timothy P. Quinn, Jolene D. Splett, Joseph D. McColskey, James Dawson, David Smith, Adam Himes, Daniel Cooke
The Transvenous Cardiac Leads Working Group of the Cardiac Rhythm Management Devices Committee of The Association for the Advancement of Medical Instrumentation (AAMI CRMD WG1) is developing a fatigue performance standard for cardiac device leads. The

Effects of Processing on Microstructure and Mechanical Properties of Ti-6Al-4V Fabricated using Electron Beam Melting (EBM), Part 2: Energy Input, Orientation, and Location

June 20, 2013
Author(s)
Nikolas W. Hrabe, Timothy P. Quinn, Ryan Kircher
Selective electron beam melting (EBM) is a layer-by-layer additive manufacturing technique that shows great promise for fabrication of medical devices and aerospace components. Before its potential can be fully realized, however, a deeper understanding of

Effects of Processing on Microstructure and Mechanical Properties of Ti-6Al-4V Fabricated using Electron Beam Melting (EBM), Part 1: Distance from Build Plate and Part Size

June 20, 2013
Author(s)
Nikolas W. Hrabe, Timothy P. Quinn, Ryan Kircher
Selective electron beam melting (EBM) is a layer-by-layer additive manufacturing technique that shows great promise for fabrication of medical devices and aerospace components. Before its potential can be fully realized, however, a deeper understanding of

Nonlinear acoustic effects in multilayer ceramic capacitors

January 25, 2013
Author(s)
Ward L. Johnson, Sudook A. Kim, Timothy P. Quinn, Grady S. White
Nonlinear resonant acoustics was explored as an approach for nondestructively evaluating the susceptibility of BaTiO3-based multilayer ceramic capacitors to electrical failure during service. The acoustic nonlinearity was characterized through measurements

An instrumented bioreactor for mechanical stimulation and real-time, nondestructive evaluation of engineered cartilage tissue

June 1, 2012
Author(s)
Jenni R. Popp, Justine Roberts, Douglas V. Gallagher, Kristi S. Anseth, Stephanie Bryant, Timothy P. Quinn
Mechanical stimulation is essential for chondrocyte metabolism and cartilage matrix deposition. In vitro, mechanical stimulation is accomplished via culture in a bioreactor. Traditional methods for evaluating the developing tissue are destructive, time

Prediction of Collagen and Glycosaminoglycan Content by Acoustic Microscopy

April 21, 2010
Author(s)
Jenni R. Popp, Colm Flannery, Tammy L. Oreskovic, Jennifer Recknor, Kristi S. Anseth, Timothy P. Quinn
Functional tissue engineering of articular cartilage is rapidly advancing as a technique to develop regenerative and reparative treatments for cartilage degeneration and osteoarthritis. Tissue engineered constructs are often developed using a combination

Tissue Engineered Scaffolds for Screening Nanoparticle - Cell Interactions

April 21, 2010
Author(s)
Kavita M. Jeerage, Elisabeth Mansfield, Tammy L. Oreskovic, Nikki S. Rentz, Timothy P. Quinn
Long-term studies of nanoparticle-cell interactions require an advanced tissue-like environment in which nanoparticles are encapsulated with a population of cells for real-time and end-point analysis. By using soft tissue-mimicking hydrogels, the cells are

An Instrumented Bioreactor for Cartilage Tissue Engineering

April 29, 2009
Author(s)
Timothy P. Quinn, Colm Flannery, Damian S. Lauria, Douglas V. Gallagher, Kristi S. Anseth
Bioreactors for in vitro growth of engineered tissue (ET) would ideally include sensors that would continuously measure the functional quality of the construct during incubation. Principles of feedback control could then be used to optimize properties of

Evaluation of Polydimethylsiloxane Modification Methods for Cell Response

February 20, 2009
Author(s)
Lisa Pakstis, Alan Zheng, Theodore V. Vorburger, Joy P. Dunkers, Timothy P. Quinn, Marcus T. Cicerone
Many methods exist in the literature to modify surfaces with extracellular matrix (ECM) proteins prior to cell attachment. However, there are few studies that systematically compare surface characterization and cell response results among different

Stiffening of the Extrapulmonary Arteries in Chronic Hypoxic Pulmonary Hypertension

July 1, 2008
Author(s)
Elizabeth S. Drexler, J. E. Bischoff, Christopher N. McCowan, Andrew Slifka, Timothy P. Quinn, R Shandas, Dunbar Ivy, K. R. Stenmark
It is increasingly appreciated that changes in the compliance properties of large blood vessels are critical determinants of ventricular afterload and ultimately dysfunction. Little is known of the mechanical properties of large vessels in the setting of

Investigations into the potential contribution of a thermal mechanism for pulsed-high intensity focused ultrasound mediated delivery

December 3, 2007
Author(s)
Brian E. O'Neill, Howard Vo, Mary Angstadt, Victor Frenkel, Bradford Wood, Timothy P. Quinn
The mechanism behind pulsed high intensity focused ultrasound (pHIFU) effects leading to increased drug delivery are currently poorly understood. In this work, the thermal dose and peak temperatures associated with a typical pHIFU treatment were measured

Dynamic Factors Contributing to Buckling and Birdnesting During GMAW Wire Feeding

June 1, 2005
Author(s)
Toby Padilla, Timothy P. Quinn, D. R. Munoz, R. A. Rorrer, John R. Berger
This study provides experimental data for determining the factors affecting wire feeding performance. Full-scale experiments show that feeding performance, in terms of wire feed speed and wire feeding force, varies with the material system and with the