Article
Engineering, Biomedical
Jordan A. Brown, Jae H. Lee, Margaret Anne Smith, David R. Wells, Aaron Barrett, Charles Puelz, John P. Vavalle, Boyce E. Griffith
Summary: Transcatheter aortic valve replacement (TAVR) is a commonly used technique for aortic valve replacement, and computer modeling and simulation (CM&S) can assist in the design and approval process of TAVR devices. This study presents a computational fluid-structure interaction (FSI) model of TAVR using the immersed finite element-difference (IFED) method.
ANNALS OF BIOMEDICAL ENGINEERING
(2023)
Article
Computer Science, Interdisciplinary Applications
Sara Barati, Nasser Fatouraee, Malikeh Nabaei, Lorenza Petrini, Francesco Migliavacca, Giulia Luraghi, Jose Felix Rodriguez Matas
Summary: The design and optimization of transcatheter heart valve replacement devices are of great importance for improving performance quality and reducing the risk of malfunction. In this study, optimal models with larger distal diameters were found to perform better in the selected objective functions.
COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE
(2022)
Article
Biotechnology & Applied Microbiology
Roberta Scuoppo, Stefano Cannata, Giovanni Gentile, Caterina Gandolfo, Salvatore Pasta
Summary: This study used finite-element analysis to quantify coronary flow in a patient who underwent TAVR-in-TAVR and found that high implantation depth and device undersize of the second THV can significantly reduce coronary flow. Additionally, a positive correlation was observed between coronary flow and the valve-to-coronary distance.
FRONTIERS IN BIOENGINEERING AND BIOTECHNOLOGY
(2023)
Article
Engineering, Biomedical
Ryan T. Helbock, Salwa B. Anam, Brandon J. Kovarovic, Marvin J. Slepian, Ashraf Hamdan, Rami Haj-Ali, Danny Bluestein
Summary: Bicuspid aortic valve (BAV) is the most common congenital heart malformation and often leads to early onset of calcific aortic stenosis (AS). Although transcatheter aortic valve replacement (TAVR) has been used to treat BAV patients, complications due to pathological BAV anatomy are common. To address these issues, a novel eccentric TAVR valve specifically designed for BAV anatomy was developed and optimized using computational modeling.
ANNALS OF BIOMEDICAL ENGINEERING
(2023)
Article
Biophysics
Tian-Yuan Xiong, Elisa Stoppani, Matthieu De Beule, Fei Chen, Yi-Jian Li, Yan-Biao Liao, Yuan Feng, Peter de Jaegere, Mao Chen
Summary: This study used patient-specific computer simulation to evaluate the force distribution on the valve frame after TAVR, finding the maximum force located at the plane of the nadir of the bioprosthetic leaflets. There were differences in the location of the maximum force and the valve frame area between patients with bicuspid aortic valve and tricuspid aortic valve.
JOURNAL OF BIOMECHANICS
(2021)
Article
Cardiac & Cardiovascular Systems
Cameron Dowling, Robert Gooley, Liam McCormick, Sami Firoozi, Stephen J. Brecker
Summary: A study found that patient-specific computer simulation can identify patients at risk for long-term adverse outcomes after transcatheter aortic valve replacement (TAVR). In this study, patients predicted to have significant paravalvular regurgitation (PVR) through computer simulation had a higher rate of death within 2 years.
JOURNAL OF CARDIOVASCULAR COMPUTED TOMOGRAPHY
(2022)
Article
Cardiac & Cardiovascular Systems
Andreas Schaefer, Till Joscha Demal, Oliver D. Bhadra, David Grundmann, Lisa Voigtlaender, Lara Waldschmidt, Johannes Schirmer, Simon Pecha, Yvonne Schneeberger, Niklas Schofer, Nils Soerensen, Stefan Blankenberg, Hermann Reichenspurner, Moritz Seiffert, Lenard Conradi
Summary: This study evaluated the hemodynamic outcomes of a latest-generation heart valve replacement device for patients with failing mitral valve or tricuspid valve through transfemoral transcatheter approach. The results showed satisfactory treatment outcomes within 30 days, with no mortality and other clinical endpoints.
FRONTIERS IN CARDIOVASCULAR MEDICINE
(2023)
Article
Biotechnology & Applied Microbiology
Guangming Zhang, Rong Liu, Min Pu, Xiaobo Zhou
Summary: This study utilized biomechanical stresses and machine learning methods to accurately predict the risk of AVB after TAVR, optimizing valve size and shape to improve clinical outcomes. The combination of biomechanical properties and machine learning significantly enhanced the prediction of surgical results.
FRONTIERS IN BIOENGINEERING AND BIOTECHNOLOGY
(2021)
Article
Biotechnology & Applied Microbiology
Salvatore Pasta, Stefano Cannata, Giovanni Gentile, Valentina Agnese, Giuseppe Maria Raffa, Michele Pilato, Caterina Gandolfo
Summary: This study conducted numerical simulations of TAVI in patients with bicuspid aortic valve (BAV) to evaluate the feasibility and risks of transcatheter heart valve (THV) implantation. Through structural mechanics and fluid-solid interaction analysis, it was found that THV exhibited slight asymmetric expansion and potential paravalvular leakage risk in BAV anatomy.
BIOENGINEERING-BASEL
(2021)
Article
Biology
Sara Barati, Nasser Fatouraee, Malikeh Nabaei, Francesca Berti, Lorenza Petrini, Francesco Migliavacca, Jose Felix Rodriguez Matas
Summary: The study developed a cost-effective optimization framework to find the optimal TAV stent design made of Ni-Ti alloy. The research showed that the number of cells and strut width of the stent play a crucial role in determining the maximum strain and stent design.
COMPUTERS IN BIOLOGY AND MEDICINE
(2021)
Review
Cardiac & Cardiovascular Systems
Paul Wong, Andrew D. Wisneski, Amitoj Sandhu, Zhongjie Wang, Vaikom S. Mahadevan, Tom C. Nguyen, Julius M. Guccione
Summary: Severe mitral valve regurgitation (MR) can lead to congestive heart failure and death if not treated. Surgical repair or replacement of the mitral valve is currently the standard treatment, but some patients may not be eligible for surgery. Transcatheter MV repair (TMVR) is emerging as an alternative, but its long-term effectiveness and comparison to surgery are still unknown. Computational modeling using techniques like finite element method and fluid structure interactions can provide insights and help guide clinicians in choosing the optimal intervention. This review discusses the relevance of computational modeling in MV repair and its future applications in treating MR.
FRONTIERS IN CARDIOVASCULAR MEDICINE
(2023)
Article
Biotechnology & Applied Microbiology
Francesco Nappi, Laura Mazzocchi, Cristiano Spadaccio, David Attias, Irina Timofeva, Laurent Macron, Adelaide Iervolino, Simone Morganti, Ferdinando Auricchio
Summary: Finite element analysis (FEA) was used to investigate the factors contributing to postoperative complications in transcatheter heart valves. The study found that calcifications persisting after device expansion could lead to geometric distortion and hemodynamic disturbances, potentially causing thrombosis. FEA may assist in patient selection, procedure planning, and detection and prevention of complications in TAVR.
BIOENGINEERING-BASEL
(2021)
Article
Cardiac & Cardiovascular Systems
Talal F. Aljabbary, Ikki Komatsu, Tomoki Ochiai, Stephen E. Fremes, Noman Ali, Lucas Burke, Mark D. Peterson, Neil P. Fam, Harindra C. Wijeysundera, Sam Radhakrishnan
Summary: This study compared the rates of new PPM implantation between patients undergoing TAVR with self-expanding valves using the conventional three-cusp technique and the cusp-overlap technique. The results showed that the cusp-overlap technique significantly reduced the rates of complete heart block and PPM implantation during hospitalization and at 30 days compared to the standard three-cusp technique.
CATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS
(2023)
Article
Engineering, Biomedical
Huang Chen, Breandan Yeats, Kevin Swamy, Milad Samaee, Sri Krishna Sivakumar, Fateme Esmailie, Atefeh Razavi, Pradeep Yadav, Vinod H. Thourani, Venkateshwar Polsani, Lakshmi Prasad Dasi
Summary: This method utilizes known device geometry and image registration-based reconstruction method to accurately recover the geometries of stent and leaflet from CT images. It has low geometric error, requires minimal human inputs, and is robust. It enables finite element analysis and reasonable estimation of stress distribution.
ANNALS OF BIOMEDICAL ENGINEERING
(2022)
Article
Cardiac & Cardiovascular Systems
Arif A. Khokhar, Francesco Ponticelli, Adriana Zlahoda-Huzior, Kailash Chandra, Rossella Ruggiero, Marco Toselli, Francesco Gallo, Alberto Cereda, Alessandro Sticchi, Alessandra Laricchia, Damiano Regazzoli, Antonio Mangieri, Bernhard Reimers, Simone Biscaglia, Carlo Tumscitz, Gianluca Campo, Ghada W. Mikhail, Won-Keun Kim, Antonio Colombo, Dariusz Dudek, Francesco Giannini
Summary: This study evaluated the feasibility and challenge of coronary access following ViV-TAVI with the supra-annular self-expandable ACURATE neo valve. The results showed that diagnostic angiography and PCI were feasible in almost all cases. Prophylactic coronary stenting, higher implantation, narrower aortic sinus dimensions, and commissural misalignment were associated with an increased challenge of coronary cannulation.
FRONTIERS IN CARDIOVASCULAR MEDICINE
(2022)
Article
Multidisciplinary Sciences
Mahdi Tavakol, Ted J. Vaughan
SCIENTIFIC REPORTS
(2020)
Article
Engineering, Biomedical
Katarzyna Polak-Krasna, Ali Reza Abaei, Reyhaneh Neghabat Shirazi, Eoin Parle, Oliver Carroll, William Ronan, Ted J. Vaughan
Summary: This study systematically evaluated the physical, thermal, and mechanical performance of medical-grade semi-crystalline PLLA undergoing thermally-accelerated degradation. The results showed a reduction in molecular weight and melting temperature, an increase in percent crystallinity, and an increase in brittleness and degradation rate over time. Despite maintaining elastic modulus and yield strength, a drastic reduction in tensile failure strain was observed beyond day 49, indicating a substantial deterioration in load-bearing capacity.
JOURNAL OF THE MECHANICAL BEHAVIOR OF BIOMEDICAL MATERIALS
(2021)
Article
Engineering, Biomedical
Ciara G. McKenna, Ted J. Vaughan
Summary: A computational framework was developed in this study to predict the functional performance of self-expanding wire braided stents, with braid angle identified as a key governing parameter for stent performance. The addition of a polymeric cover was found to cause a stiffer radial response for the wire braided stents.
JOURNAL OF THE MECHANICAL BEHAVIOR OF BIOMEDICAL MATERIALS
(2021)
Article
Materials Science, Biomaterials
Felix Benn, Nadja Kroger, Max Zinser, Kerstin van Gaalen, Ted J. Vaughan, Ming Yan, Ralf Smeets, Eric Bibiza, Savko Malinov, Fraser Buchanan, Alexander Kopp
Summary: The further development of future Magnesium based biodegradable implants needs to consider both design freedom and implant volume reduction, with laser powder bed fusion (LPBF) being introduced as a promising manufacturing method.
MATERIALS SCIENCE AND ENGINEERING C-MATERIALS FOR BIOLOGICAL APPLICATIONS
(2021)
Article
Multidisciplinary Sciences
Ivor P. Geoghegan, Laoise M. McNamara, David A. Hoey
Summary: Estrogen deficiency in post-menopausal osteoporosis leads to osteoclastogenesis and bone loss. Increased pro-osteoclastogenic signaling by osteocytes following estrogen withdrawal is associated with a disrupted actin cytoskeleton. Hedgehog signaling in osteocytes is involved in RANKL production, and the elongation of cilia is linked to a reduction in focal adhesions and actin contractility.
SCIENTIFIC REPORTS
(2021)
Review
Chemistry, Multidisciplinary
Gabriele Nasello, Mar Condor, Ted Vaughan, Jessica Schiavi
Summary: The recent development of bone-on-chips (BOCs) utilizes minimal cell and material quantity and incorporates hydrogels to create a three-dimensional culture environment. This technology allows for mimicking various cell growth environments and personalized therapy development.
APPLIED SCIENCES-BASEL
(2021)
Article
Biophysics
Mahdi Tavakol, Ted J. Vaughan
Summary: This study investigated the role of calcium ions on energy dissipation at the interface between osteopontin (OPN) and hydroxyapatite (HAp). It found that calcium ions greatly influenced the structure and energy dissipation performance of OPN proteins. Under small deformation, the compact OPN structure facilitated greater energy dissipation through mechanisms mediated by surface-bound calcium and sacrificial bond breaking. At larger deformation, the compact structure also enabled OPN to dissipate higher energy. Phosphorylation of OPN also played an important role in energy dissipation.
BIOPHYSICAL JOURNAL
(2022)
Article
Engineering, Biomedical
Constantino Fiuza, Katarzyna Polak-Krasna, Luca Antonini, Lorenza Petrini, Oliver Carroll, William Ronan, Ted J. Vaughan
Summary: The study evaluated the mechanical, micro-mechanical, and physical properties of Reva Medical Fantom Encore Bioresorbable Scaffolds subjected to thermally-accelerated degradation. Results showed an initial increase in radial strength and stiffness, followed by a decrease in ductility and load-bearing capacity with continued degradation. The scaffolds exhibited increased crystallinity throughout the degradation process, with minimal changes in nano-mechanical properties.
JOURNAL OF THE MECHANICAL BEHAVIOR OF BIOMEDICAL MATERIALS
(2022)
Review
Endocrinology & Metabolism
Laoise M. McNamara
Summary: Postmenopausal osteoporosis is not only characterized by bone loss due to decreased estrogen levels, but also by alterations in mechanosensitive osteocytes. Research shows that estrogen deficiency affects the osteocyte mechanical and microenvironment, leading to impaired mechanobiological responses and exacerbating osteocyte regulation of osteoclasts. Understanding these changes is crucial for developing targeted therapies to inhibit resorption and secondary mineralization in osteoporosis.
CURRENT OSTEOPOROSIS REPORTS
(2021)
Article
Cardiac & Cardiovascular Systems
Ciara G. McKenna, Ted J. Vaughan
Summary: This study found that stent covering increases initial axial stiffness and up to 60% greater radial resistive force at small crimp diameters. The use of a stiffer PET polymeric covering material significantly alters the radial and axial response of the stent.
CARDIOVASCULAR ENGINEERING AND TECHNOLOGY
(2022)
Article
Engineering, Biomedical
Kerstin van Gaalen, Felix Gremse, Felix Benn, Peter E. McHugh, Alexander Kopp, Ted J. Vaughan
Summary: This study develops an automated detection framework (PitScan) using Python-based algorithm to evaluate the severity and phenomenology of pitting corrosion. The framework analyzes microcomputer-tomography scans (mu CT) of corroded cylindrical specimens and identifies surface-based corrosion features, providing a spatial characterization of pitting parameters. The study also establishes relationships between key pitting parameters and mechanical performance in Rare Earth Magnesium alloy specimens. The results show that certain parameters described in ASTM G46-94 have little correlation with mechanical performance, while parameters directly linked to the reduction of cross-sectional area are more indicative of specimen's mechanical performance. The developed automated detection framework has the potential to standardize pitting corrosion measurements and predict mechanical strength degradation over time.
BIOACTIVE MATERIALS
(2022)
Article
Biology
Monika Colombo, Anna Corti, Diego Gallo, Andrea Colombo, Giacomo Antognoli, Martina Bernini, Ciara McKenna, Scott Berceli, Ted Vaughan, Francesco Migliavacca, Claudio Chiastra
Summary: This study analyzed the impact of stent design and stent overlapping on patient-specific SFA hemodynamics. The results showed that different stent designs and overlapping configurations significantly altered the hemodynamic parameters. Stent design type and overlapping length had a significant impact on the hemodynamics.
COMPUTERS IN BIOLOGY AND MEDICINE
(2022)
Article
Engineering, Biomedical
Hamid Alijani, Ted J. Vaughan
Summary: This study investigates the effects of intra- and extra-fibrillar mineralization on the elastic properties of lamellar bone tissue through a multiscale finite element analysis. The results demonstrate that the overall mineral content in the tissue is the biggest contributor to the effective elastic properties of lamellar bone, and the extra-fibrillar matrix plays a primary role in the elastic response of the tissue.
JOURNAL OF THE MECHANICAL BEHAVIOR OF BIOMEDICAL MATERIALS
(2022)
Proceedings Paper
Engineering, Biomedical
Georgia S. Karanasiou, Panagiota I. Tsobou, Nikolaos S. Tachos, Luca Antonini, Lorenza Petrini, Giancarlo Pennati, Frank Gijsen, Farhad Rikhtegar Nezami, Rami Tzafiri, Ted Vaughan, Martin Fawdry, Dimitrios I. Fotiadis
42ND ANNUAL INTERNATIONAL CONFERENCES OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY: ENABLING INNOVATIVE TECHNOLOGIES FOR GLOBAL HEALTHCARE EMBC'20
(2020)
Article
Multidisciplinary Sciences
Kimberly J. Curtis, Jessica Schiavi, Myles J. Mc Garrigle, Vatsal Kumar, Laoise M. McNamara, Glen L. Niebur
JOURNAL OF THE ROYAL SOCIETY INTERFACE
(2020)