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Holroyd NA, Walsh C, Gourmet L, Walker-Samuel S. Quantitative Image Processing for Three-Dimensional Episcopic Images of Biological Structures: Current State and Future Directions. Biomedicines 2023; 11:909. [PMID: 36979887 PMCID: PMC10045950 DOI: 10.3390/biomedicines11030909] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Revised: 03/03/2023] [Accepted: 03/10/2023] [Indexed: 03/17/2023] Open
Abstract
Episcopic imaging using techniques such as High Resolution Episcopic Microscopy (HREM) and its variants, allows biological samples to be visualized in three dimensions over a large field of view. Quantitative analysis of episcopic image data is undertaken using a range of methods. In this systematic review, we look at trends in quantitative analysis of episcopic images and discuss avenues for further research. Papers published between 2011 and 2022 were analyzed for details about quantitative analysis approaches, methods of image annotation and choice of image processing software. It is shown that quantitative processing is becoming more common in episcopic microscopy and that manual annotation is the predominant method of image analysis. Our meta-analysis highlights where tools and methods require further development in this field, and we discuss what this means for the future of quantitative episcopic imaging, as well as how annotation and quantification may be automated and standardized across the field.
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Affiliation(s)
| | - Claire Walsh
- Centre for Computational Medicine, University College London, London WC1E 6DD, UK
- Department of Mechanical Engineering, University College London, London WC1E 7JE, UK
| | - Lucie Gourmet
- Centre for Computational Medicine, University College London, London WC1E 6DD, UK
| | - Simon Walker-Samuel
- Centre for Computational Medicine, University College London, London WC1E 6DD, UK
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2
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Siddiqui HB, Dogru S, Lashkarinia SS, Pekkan K. Soft-Tissue Material Properties and Mechanogenetics during Cardiovascular Development. J Cardiovasc Dev Dis 2022; 9:jcdd9020064. [PMID: 35200717 PMCID: PMC8876703 DOI: 10.3390/jcdd9020064] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Revised: 01/22/2022] [Accepted: 01/28/2022] [Indexed: 12/17/2022] Open
Abstract
During embryonic development, changes in the cardiovascular microstructure and material properties are essential for an integrated biomechanical understanding. This knowledge also enables realistic predictive computational tools, specifically targeting the formation of congenital heart defects. Material characterization of cardiovascular embryonic tissue at consequent embryonic stages is critical to understand growth, remodeling, and hemodynamic functions. Two biomechanical loading modes, which are wall shear stress and blood pressure, are associated with distinct molecular pathways and govern vascular morphology through microstructural remodeling. Dynamic embryonic tissues have complex signaling networks integrated with mechanical factors such as stress, strain, and stiffness. While the multiscale interplay between the mechanical loading modes and microstructural changes has been studied in animal models, mechanical characterization of early embryonic cardiovascular tissue is challenging due to the miniature sample sizes and active/passive vascular components. Accordingly, this comparative review focuses on the embryonic material characterization of developing cardiovascular systems and attempts to classify it for different species and embryonic timepoints. Key cardiovascular components including the great vessels, ventricles, heart valves, and the umbilical cord arteries are covered. A state-of-the-art review of experimental techniques for embryonic material characterization is provided along with the two novel methods developed to measure the residual and von Mises stress distributions in avian embryonic vessels noninvasively, for the first time in the literature. As attempted in this review, the compilation of embryonic mechanical properties will also contribute to our understanding of the mature cardiovascular system and possibly lead to new microstructural and genetic interventions to correct abnormal development.
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Affiliation(s)
- Hummaira Banu Siddiqui
- Department of Mechanical Engineering, Koc University, Istanbul 34450, Turkey; (H.B.S.); (S.D.); (S.S.L.)
| | - Sedat Dogru
- Department of Mechanical Engineering, Koc University, Istanbul 34450, Turkey; (H.B.S.); (S.D.); (S.S.L.)
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
| | - Seyedeh Samaneh Lashkarinia
- Department of Mechanical Engineering, Koc University, Istanbul 34450, Turkey; (H.B.S.); (S.D.); (S.S.L.)
- Department of Bioengineering, Imperial College London, London SW7 2BX, UK
| | - Kerem Pekkan
- Department of Mechanical Engineering, Koc University, Istanbul 34450, Turkey; (H.B.S.); (S.D.); (S.S.L.)
- Correspondence: ; Tel.: +90-(533)-356-3595
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3
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Saw SN, Dai Y, Yap CH. A Review of Biomechanics Analysis of the Umbilical-Placenta System With Regards to Diseases. Front Physiol 2021; 12:587635. [PMID: 34475826 PMCID: PMC8406807 DOI: 10.3389/fphys.2021.587635] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 07/19/2021] [Indexed: 11/13/2022] Open
Abstract
Placenta is an important organ that is crucial for both fetal and maternal health. Abnormalities of the placenta, such as during intrauterine growth restriction (IUGR) and pre-eclampsia (PE) are common, and an improved understanding of these diseases is needed to improve medical care. Biomechanics analysis of the placenta is an under-explored area of investigation, which has demonstrated usefulness in contributing to our understanding of the placenta physiology. In this review, we introduce fundamental biomechanics concepts and discuss the findings of biomechanical analysis of the placenta and umbilical cord, including both tissue biomechanics and biofluid mechanics. The biomechanics of placenta ultrasound elastography and its potential in improving clinical detection of placenta diseases are also discussed. Finally, potential future work is listed.
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Affiliation(s)
- Shier Nee Saw
- Department of Biomedical Engineering, National University of Singapore, Singapore, Singapore
| | - Yichen Dai
- Department of Biomedical Engineering, National University of Singapore, Singapore, Singapore
| | - Choon Hwai Yap
- Department of Bioengineering, Imperial College London, London, United Kingdom
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4
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Bappoo N, Kelsey LJ, Tongpob Y, Wyrwoll C, Doyle BJ. Investigating the Upstream and Downstream Hemodynamic Boundary Conditions of Healthy and Growth-Restricted Rat Feto-Placental Arterial Networks. Ann Biomed Eng 2021; 49:2183-2195. [PMID: 33646497 DOI: 10.1007/s10439-021-02749-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Accepted: 02/05/2021] [Indexed: 11/30/2022]
Abstract
The placenta uniquely develops to orchestrate maternal adaptations and support fetal growth and development. The expansion of the feto-placental vascular network, in part, underpins function. However it is unclear how vascular development is synergistically influenced by hemodynamics and how impairment may lead to fetal growth restriction (FGR). Here, we present a robust framework consisting of ex vivo placental casting, imaging and computational fluid dynamics of rat feto-placental networks where we investigate inlet (steady and transient) and outlet (zero-pressure, Murray's Law, asymmetric fractal trees and porous blocks) boundary conditions in a model of growth-restriction. We show that the Murray's Law flow-split boundary condition is not always appropriate and that mean steady-state inlet conditions produce comparable results to transient flow. However, we conclude that transient simulations should be adopted as they provide a larger amount of valuable data, a necessity to bridge the current knowledge gap in placental biomechanics. We also show preliminary data on changes in flow, shear stress, and flow deceleration between control and growth-restricted feto-placental networks. Our proposed framework provides a standardized approach for structural and hemodynamic analysis of feto-placental vasculature and has the potential to enhance our understanding of placental function.
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Affiliation(s)
- Nikhilesh Bappoo
- Vascular Engineering Laboratory, Harry Perkins Institute of Medical Research, QEII Medical Centre and the UWA Centre for Medical Research, The University of Western Australia, Nedlands, WA, 6009, Australia.
- School of Engineering, The University of Western Australia, Perth, WA, 6009, Australia.
- School of Human Sciences, The University of Western Australia, Perth, WA, 6009, Australia.
| | - Lachlan J Kelsey
- Vascular Engineering Laboratory, Harry Perkins Institute of Medical Research, QEII Medical Centre and the UWA Centre for Medical Research, The University of Western Australia, Nedlands, WA, 6009, Australia
- School of Engineering, The University of Western Australia, Perth, WA, 6009, Australia
| | - Yutthapong Tongpob
- School of Human Sciences, The University of Western Australia, Perth, WA, 6009, Australia
- Faculty of Medical Science, Naresuan University, Phitsanulok, Thailand
| | - Caitlin Wyrwoll
- School of Human Sciences, The University of Western Australia, Perth, WA, 6009, Australia
| | - Barry J Doyle
- Vascular Engineering Laboratory, Harry Perkins Institute of Medical Research, QEII Medical Centre and the UWA Centre for Medical Research, The University of Western Australia, Nedlands, WA, 6009, Australia
- School of Engineering, The University of Western Australia, Perth, WA, 6009, Australia
- Australian Research Council Centre for Personalised Therapeutics Technologies, Melbourne, Australia
- BHF Centre of Cardiovascular Science, The University of Edinburgh, Edinburgh, EH9 3FD, UK
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Rodriguez D, Taketa DA, Madhu R, Kassmer S, Loerke D, Valentine MT, Tomaso AWD. Vascular Aging in the Invertebrate Chordate, Botryllus schlosseri. Front Mol Biosci 2021; 8:626827. [PMID: 33898513 PMCID: PMC8060491 DOI: 10.3389/fmolb.2021.626827] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Accepted: 03/03/2021] [Indexed: 12/13/2022] Open
Abstract
Vascular diseases affect over 1 billion people worldwide and are highly prevalent among the elderly, due to a progressive deterioration of the structure of vascular cells. Most of our understanding of these age-related cellular changes comes from in vitro studies on human cell lines. Further studies of the mechanisms underlying vascular aging in vivo are needed to provide insight into the pathobiology of age-associated vascular diseases, but are difficult to carry out on vertebrate model organisms. We are studying the effects of aging on the vasculature of the invertebrate chordate, Botryllus schlosseri. This extracorporeal vascular network of Botryllus is transparent and particularly amenable to imaging and manipulation. Here we use a combination of transcriptomics, immunostaining and live-imaging, as well as in vivo pharmacological treatments and regeneration assays to show that morphological, transcriptional, and functional age-associated changes within vascular cells are key hallmarks of aging in B. schlosseri, and occur independent of genotype. We show that age-associated changes in the cytoskeleton and the extracellular matrix reshape vascular cells into a flattened and elongated form and there are major changes in the structure of the basement membrane over time. The vessels narrow, reducing blood flow, and become less responsive to stimuli inducing vascular regression. The extracorporeal vasculature is highly regenerative following injury, and while age does not affect the regeneration potential, newly regenerated vascular cells maintain the same aged phenotype, suggesting that aging of the vasculature is a result of heritable epigenetic changes.
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Affiliation(s)
- Delany Rodriguez
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA, United States
| | - Daryl A. Taketa
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA, United States
| | - Roopa Madhu
- Department of Physics and Astronomy, University of Denver, Denver, CO, United States
| | - Susannah Kassmer
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA, United States
| | - Dinah Loerke
- Department of Physics and Astronomy, University of Denver, Denver, CO, United States
| | - Megan T. Valentine
- Department of Mechanical Engineering, University of California, Santa Barbara, Santa Barbara, CA, United States
| | - Anthony W. De Tomaso
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA, United States
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6
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Lee Y, Veerubhotla K, Jeong MH, Lee CH. Deep Learning in Personalization of Cardiovascular Stents. J Cardiovasc Pharmacol Ther 2020; 25:110-120. [DOI: 10.1177/1074248419878405] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 08/30/2023]
Abstract
Deep learning (DL) application has demonstrated its enormous potential in accomplishing biomedical tasks, such as vessel segmentation, brain visualization, and speech recognition. This review article has mainly covered recent advances in the principles of DL algorithms, existing DL software, and designing strategies of DL models. Latest progresses in cardiovascular devices, especially DL-based cardiovascular stent used for angioplasty, differential and advanced diagnostic means, and the treatment outcomes involved with coronary artery disease (CAD), are discussed. Also presented is DL-based discovery of new materials and future medical technologies that will facilitate the development of tailored and personalized treatment strategies by identifying and forecasting individual impending risks of cardiovascular diseases.
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Affiliation(s)
- Yugyung Lee
- School of Computing and Engineering, University of Missouri-Kansas City, MO, USA
| | - Krishna Veerubhotla
- Division of Pharmaceutical Sciences, School of Pharmacy, University of Missouri-Kansas City, MO, USA
| | - Myung Ho Jeong
- Department of Cardiovascular Medicine of Chonnam National University, Gwang-Ju, South Korea
| | - Chi H. Lee
- Division of Pharmaceutical Sciences, School of Pharmacy, University of Missouri-Kansas City, MO, USA
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Ho S, Chan WX, Rajesh S, Phan-Thien N, Yap CH. Fluid dynamics and forces in the HH25 avian embryonic outflow tract. Biomech Model Mechanobiol 2019; 18:1123-1137. [PMID: 30810888 DOI: 10.1007/s10237-019-01132-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Accepted: 02/11/2019] [Indexed: 11/26/2022]
Abstract
The embryonic outflow tract (OFT) eventually undergoes aorticopulmonary septation to form the aorta and pulmonary artery, and it is hypothesized that blood flow mechanical forces guide this process. We performed detailed studies of the geometry, wall motions, and fluid dynamics of the HH25 chick embryonic OFT just before septation, using noninvasive 4D high-frequency ultrasound and computational flow simulations. The OFT exhibited expansion and contraction waves propagating from proximal to distal end, with periods of luminal collapse at locations of the two endocardial cushions. This, combined with periods of reversed flow, resulted in the OFT cushions experiencing wall shear stresses (WSS or flow drag forces) with elevated oscillatory characteristics, which could be important to signal for further development of cushions into valves and septum. Furthermore, the OFT exhibits interesting double-helical flow during systole, where a pair of helical flow structures twisted about each other from the proximal to distal end. This coincided with the location of the future aorticopulmonary septum, which also twisted from the proximal to distal end, suggesting that this flow pattern may be guiding OFT septation.
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Affiliation(s)
- Sheldon Ho
- Department of Biomedical Engineering, National University of Singapore, Singapore, Singapore
| | - Wei Xuan Chan
- Department of Biomedical Engineering, National University of Singapore, Singapore, Singapore
| | - Shreyas Rajesh
- Department of Biomedical Engineering, National University of Singapore, Singapore, Singapore
| | - Nhan Phan-Thien
- Department of Mechanical Engineering, National University of Singapore, Singapore, Singapore
| | - Choon Hwai Yap
- Department of Biomedical Engineering, National University of Singapore, Singapore, Singapore.
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8
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Hatoum H, Dollery J, Lilly SM, Crestanello JA, Dasi LP. Sinus Hemodynamics Variation with Tilted Transcatheter Aortic Valve Deployments. Ann Biomed Eng 2019; 47:75-84. [PMID: 30151733 PMCID: PMC6376402 DOI: 10.1007/s10439-018-02120-0] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Accepted: 08/17/2018] [Indexed: 12/18/2022]
Abstract
Leaflet thrombosis is a complication associated with transcatheter aortic valve (TAV) replacement (TAVR) correlated with sinus flow stasis. Sinus hemodynamics are important because they dictate shear stress and washout necessary to avoid stasis on TAV leaflets. Sinus flow is controlled by TAV axial deployment position but little is known regarding TAV axis misalignment effect. This study aims to elucidate TAV angular misalignment with respect to aortic root axis effect on sinus flow stasis potentially leading to leaflet thrombosis. Sinus hemodynamics were assessed in vitro using particle-image velocimetry in three different angular misalignments with respect to aorta axis: untilted, tilted away from the sinus and tilted towards sinus. A 26 mm Edwards SAPIEN3 was implanted in a 3D printed model of an anatomically realistic aortic root. TAV hemodynamics, sinus vortex tracking, leaflet shear stress probability density functions, and sinus blood time to washout were calculated. While pressure gradients differed insignificantly, blood velocity and vorticity decreased significantly in both tilted cases sinuses. Shear stress probability near the leaflet decreases with tilt indicating stasis. TAV tilted away from the sinus is the most unfavorable scenario with poor washout. TAV axial misalignment adds to factors list that could influence leaflet thrombosis risk through modifying sinus hemodynamics and washout.
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Affiliation(s)
- Hoda Hatoum
- Department of Biomedical Engineering, The Ohio State University, 473 W 12th Ave., Columbus, OH, 43210, USA
| | - Jennifer Dollery
- Division of Cardiac Surgery, The Ohio State University, Columbus, OH, USA
| | - Scott M Lilly
- Division of Cardiovascular Medicine, The Ohio State University, Columbus, OH, USA
| | - Juan A Crestanello
- Division of Cardiac Surgery, The Ohio State University, Columbus, OH, USA
| | - Lakshmi Prasad Dasi
- Department of Biomedical Engineering, The Ohio State University, 473 W 12th Ave., Columbus, OH, 43210, USA.
- Division of Cardiac Surgery, The Ohio State University, Columbus, OH, USA.
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Craven BA, Aycock KI, Manning KB. Steady Flow in a Patient-Averaged Inferior Vena Cava—Part II: Computational Fluid Dynamics Verification and Validation. Cardiovasc Eng Technol 2018; 9:654-673. [DOI: 10.1007/s13239-018-00392-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Accepted: 10/27/2018] [Indexed: 12/31/2022]
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10
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Wiputra H, Chen CK, Talbi E, Lim GL, Soomar SM, Biswas A, Mattar CNZ, Bark D, Leo HL, Yap CH. Human fetal hearts with tetralogy of Fallot have altered fluid dynamics and forces. Am J Physiol Heart Circ Physiol 2018; 315:H1649-H1659. [PMID: 30216114 DOI: 10.1152/ajpheart.00235.2018] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Studies have suggested the effect of blood flow forces in pathogenesis and progression of some congenital heart malformations. It is therefore of interest to study the fluid mechanic environment of the malformed prenatal heart, such as the tetralogy of Fallot (TOF), especially when little is known about fetal TOF. In this study, we performed patient-specific ultrasound-based flow simulations of three TOF and seven normal human fetal hearts. TOF right ventricles (RVs) had smaller end-diastolic volumes (EDVs) but similar stroke volumes (SVs), whereas TOF left ventricles (LVs) had similar EDVs but slightly increased SVs compared with normal ventricles. Simulations showed that TOF ventricles had elevated systolic intraventricular pressure gradient (IVPG) and required additional energy for ejection but IVPG elevations were considered to be mild relative to arterial pressure. TOF RVs and LVs had similar pressures because of equalization via ventricular septal defect (VSD). Furthermore, relative to normal, TOF RVs had increased diastolic wall shear stresses (WSS) but TOF LVs were not. This was caused by high tricuspid inflow that exceeded RV SV, leading to right-to-left shunting and chaotic flow with enhanced vorticity interaction with the wall to elevate WSS. Two of the three TOF RVs but none of the LVs had increased thickness. As pressure elevations were mild, we hypothesized that pressure and WSS elevation could play a role in the RV thickening, among other causative factors. Finally, the endocardium surrounding the VSD consistently experienced high WSS because of RV-to-LV flow shunt and high flow rate through the over-riding aorta. NEW & NOTEWORTHY Blood flow forces are thought to cause congenital heart malformations and influence disease progression. We performed novel investigations of intracardiac fluid mechanics of tetralogy of Fallot (TOF) human fetal hearts and found essential differences from normal hearts. The TOF right ventricle (RV) and left ventricle had similar and elevated pressure but only the TOF RV had elevated wall shear stress because of elevated tricuspid inflow, and this may contribute to the observed RV thickening. TOF hearts also expended more energy for ejection.
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Affiliation(s)
- Hadi Wiputra
- Department of Biomedical Engineering, National University of Singapore , Singapore
| | - Ching Kit Chen
- Division of Cardiology, Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore, National University Health System , Singapore
| | - Elias Talbi
- Department of Biomedical Engineering, National University of Singapore , Singapore
| | - Guat Ling Lim
- Department of Obstetrics and Gynecology, Yong Loo Lin School of Medicine, National University of Singapore, National University Health System , Singapore
| | - Sanah Merchant Soomar
- Division of Cardiology, Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore, National University Health System , Singapore
| | - Arijit Biswas
- Department of Obstetrics and Gynecology, Yong Loo Lin School of Medicine, National University of Singapore, National University Health System , Singapore
| | - Citra Nurfarah Zaini Mattar
- Department of Obstetrics and Gynecology, Yong Loo Lin School of Medicine, National University of Singapore, National University Health System , Singapore
| | - David Bark
- Department of Mechanical Engineering, Colorado State University , Fort Collins, Colorado
| | - Hwa Liang Leo
- Department of Biomedical Engineering, National University of Singapore , Singapore
| | - Choon Hwai Yap
- Department of Biomedical Engineering, National University of Singapore , Singapore
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11
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Sinus Hemodynamics in Representative Stenotic Native Bicuspid and Tricuspid Aortic Valves: An In-Vitro Study. FLUIDS 2018. [DOI: 10.3390/fluids3030056] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
(1) The study’s objective is to assess sinus hemodynamics differences between stenotic native bicuspid aortic valve (BAV) and native tricuspid aortic valve (TrAV) sinuses in order to assess sinus flow shear and vorticity dynamics in these common pathological states of the aortic valve. (2) Representative patient-specific aortic roots with BAV and TrAV were selected, segmented, and 3D printed. The flow dynamics within the sinus were assessed in-vitro using particle image velocimetry in a left heart simulator at physiological pressure and flow conditions. Hemodynamic data calculations, vortex tracking, shear stress probability density functions and sinus washout calculations based on Lagrangian particle tracking were performed. (3) (a) At peak systole, velocity and vorticity in BAV reach 0.67 ± 0.02 m/s and 374 ± 5 s−1 versus 0.49 ± 0.03 m/s and 293 ± 3 s−1 in TrAV; (b) Aortic sinus vortex is slower to form but conserved in BAV sinus; (c) BAV shear stresses exceed those of TrAV (1.05 Pa versus 0.8 Pa); (d) Complete TrAV washout was achieved after 1.5 cycles while it was not for BAV. 4) In conclusion, sinus hemodynamics dependence on the different native aortic valve types and sinus morphologies was clearly highlighted in this study.
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12
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Ko ZYG, Mehta K, Jamil M, Yap CH, Chen N. A method to study the hemodynamics of chicken embryo's aortic arches using optical coherence tomography. JOURNAL OF BIOPHOTONICS 2017; 10:353-359. [PMID: 27813365 DOI: 10.1002/jbio.201600119] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Revised: 08/31/2016] [Accepted: 09/30/2016] [Indexed: 05/19/2023]
Abstract
Congenital cardiovascular defects are the leading cause of birth defect related death. It has been hypothesized that fluid mechanical forces of embryonic blood flow affect cardiovascular development and play a role in congenital malformations. Studies in small animal embryos can improve our understanding of congenital malformations and can lead to better treatment. We present a feasibility study in which high-resolution optical coherence tomography (OCT) and computational fluid dynamics (CFD) are combined to provide quantitative analysis of the embryonic flow mechanics and the associated anatomy in a small animal model.
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Affiliation(s)
- Zhen Yu Gordon Ko
- Department of Biomedical Engineering, National University of Singapore, Block E4 #04-08, 4 Engineering Drive 3, Singapore, 117583
| | - Kalpesh Mehta
- Department of Biomedical Engineering, National University of Singapore, Block E4 #04-08, 4 Engineering Drive 3, Singapore, 117583
| | - Muhammad Jamil
- Department of Biomedical Engineering, National University of Singapore, Block E4 #04-08, 4 Engineering Drive 3, Singapore, 117583
| | - Choon Hwai Yap
- Department of Biomedical Engineering, National University of Singapore, Block E4 #04-08, 4 Engineering Drive 3, Singapore, 117583
| | - Nanguang Chen
- Department of Biomedical Engineering, National University of Singapore, Block E4 #04-08, 4 Engineering Drive 3, Singapore, 117583
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13
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Subramaniam DR, Stoddard WA, Mortensen KH, Ringgaard S, Trolle C, Gravholt CH, Gutmark EJ, Mylavarapu G, Backeljauw PF, Gutmark-Little I. Continuous measurement of aortic dimensions in Turner syndrome: a cardiovascular magnetic resonance study. J Cardiovasc Magn Reson 2017; 19:20. [PMID: 28231838 PMCID: PMC5324249 DOI: 10.1186/s12968-017-0336-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2017] [Accepted: 02/02/2017] [Indexed: 01/15/2023] Open
Abstract
BACKGROUND Severity of thoracic aortic disease in Turner syndrome (TS) patients is currently described through measures of aorta size and geometry at discrete locations. The objective of this study is to develop an improved measurement tool that quantifies changes in size and geometry over time, continuously along the length of the thoracic aorta. METHODS Cardiovascular magnetic resonance (CMR) scans for 15 TS patients [41 ± 9 years (mean age ± standard deviation (SD))] were acquired over a 10-year period and compared with ten healthy gender and age-matched controls. Three-dimensional aortic geometries were reconstructed, smoothed and clipped, which was followed by identification of centerlines and planes normal to the centerlines. Geometric variables, including maximum diameter and cross-sectional area, were evaluated continuously along the thoracic aorta. Distance maps were computed for TS and compared to the corresponding maps for controls, to highlight any asymmetry and dimensional differences between diseased and normal aortae. Furthermore, a registration scheme was proposed to estimate localized changes in aorta geometry between visits. The estimated maximum diameter from the continuous method was then compared with corresponding manual measurements at 7 discrete locations for each visit and for changes between visits. RESULTS Manual measures at the seven positions and the corresponding continuous measurements of maximum diameter for all visits considered, correlated highly (R-value = 0.77, P < 0.01). There was good agreement between manual and continuous measurement methods for visit-to-visit changes in maximum diameter. The continuous method was less sensitive to inter-user variability [0.2 ± 2.3 mm (mean difference in diameters ± SD)] and choice of smoothing software [0.3 ± 1.3 mm]. Aortic diameters were larger in TS than controls in the ascending [TS: 13.4 ± 2.1 mm (mean distance ± SD), Controls: 12.6 ± 1 mm] and descending [TS: 10.2 ± 1.3 mm (mean distance ± SD), Controls: 9.5 ± 0.9 mm] thoracic aorta as observed from the distance maps. CONCLUSIONS An automated methodology is presented that enables rapid and precise three-dimensional measurement of thoracic aortic geometry, which can serve as an improved tool to define disease severity and monitor disease progression. TRIAL REGISTRATION ClinicalTrials.gov Identifier - NCT01678274 . Registered - 08.30.2012.
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Affiliation(s)
| | - William A. Stoddard
- Department of Aerospace Engineering and Engineering Mechanics, CEAS, University of Cincinnati, Cincinnati, OH USA
| | - Kristian H. Mortensen
- Cardio-respiratory Unit, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Steffen Ringgaard
- Institute for Clinical Medicine, Aarhus University, Aarhus N, Denmark
| | - Christian Trolle
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus C, Denmark
| | - Claus H. Gravholt
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus C, Denmark
- Department of Molecular Medicine, Aarhus University Hospital, Aarhus N, Denmark
| | - Ephraim J. Gutmark
- Department of Aerospace Engineering and Engineering Mechanics, CEAS, University of Cincinnati, Cincinnati, OH USA
- UC Department of Otolaryngology, Head and Neck Surgery, Cincinnati, OH USA
| | - Goutham Mylavarapu
- Division of Pulmonary Medicine, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH USA
| | - Philippe F. Backeljauw
- Division of Endocrinology, Department of Pediatrics, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229 USA
| | - Iris Gutmark-Little
- Division of Endocrinology, Department of Pediatrics, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229 USA
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Goktas S, Uslu FE, Kowalski WJ, Ermek E, Keller BB, Pekkan K. Time-Series Interactions of Gene Expression, Vascular Growth and Hemodynamics during Early Embryonic Arterial Development. PLoS One 2016; 11:e0161611. [PMID: 27552150 PMCID: PMC4994943 DOI: 10.1371/journal.pone.0161611] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Accepted: 08/09/2016] [Indexed: 11/18/2022] Open
Abstract
The role of hemodynamic forces within the embryo as biomechanical regulators for cardiovascular morphogenesis, growth, and remodeling is well supported through the experimental studies. Furthermore, clinical experience suggests that perturbed flow disrupts the normal vascular growth process as one etiology for congenital heart diseases (CHD) and for fetal adaptation to CHD. However, the relationships between hemodynamics, gene expression and embryonic vascular growth are poorly defined due to the lack of concurrent, sequential in vivo data. In this study, a long-term, time-lapse optical coherence tomography (OCT) imaging campaign was conducted to acquire simultaneous blood velocity, pulsatile micro-pressure and morphometric data for 3 consecutive early embryonic stages in the chick embryo. In conjunction with the in vivo growth and hemodynamics data, in vitro reverse transcription polymerase chain reaction (RT-PCR) analysis was performed to track changes in transcript expression relevant to histogenesis and remodeling of the embryonic arterial wall. Our non-invasive extended OCT imaging technique for the microstructural data showed continuous vessel growth. OCT data coupled with the PIV technique revealed significant but intermitted increases in wall shear stress (WSS) between first and second assigned stages and a noticeable decrease afterwards. Growth rate, however, did not vary significantly throughout the embryonic period. Among all the genes studied, only the MMP-2 and CASP-3 expression levels remained unchanged during the time course. Concurrent relationships were obtained among the transcriptional modulation of the genes, vascular growth and hemodynamics-related changes. Further studies are indicated to determine cause and effect relationships and reversibility between mechanical and molecular regulation of vasculogenesis.
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Affiliation(s)
- Selda Goktas
- Mechanical Engineering Department, Koc University, Istanbul, Turkey
| | - Fazil E. Uslu
- Mechanical Engineering Department, Koc University, Istanbul, Turkey
| | - William J. Kowalski
- Kosair Charities Pediatric Heart Research Program, Cardiovascular Innovation Institute, University of Louisville, Louisville, KY, United States of America
| | - Erhan Ermek
- Mechanical Engineering Department, Koc University, Istanbul, Turkey
| | - Bradley B. Keller
- Kosair Charities Pediatric Heart Research Program, Cardiovascular Innovation Institute, University of Louisville, Louisville, KY, United States of America
| | - Kerem Pekkan
- Mechanical Engineering Department, Koc University, Istanbul, Turkey
- * E-mail:
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15
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Saw SN, Dawn C, Biswas A, Mattar CNZ, Yap CH. Characterization of the in vivo wall shear stress environment of human fetus umbilical arteries and veins. Biomech Model Mechanobiol 2016; 16:197-211. [DOI: 10.1007/s10237-016-0810-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Accepted: 07/20/2016] [Indexed: 10/21/2022]
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16
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De Wilde D, Trachet B, De Meyer G, Segers P. The influence of anesthesia and fluid-structure interaction on simulated shear stress patterns in the carotid bifurcation of mice. J Biomech 2016; 49:2741-2747. [PMID: 27342001 DOI: 10.1016/j.jbiomech.2016.06.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Revised: 05/04/2016] [Accepted: 06/07/2016] [Indexed: 01/04/2023]
Abstract
BACKGROUND Low and oscillatory wall shear stresses (WSS) near aortic bifurcations have been linked to the onset of atherosclerosis. In previous work, we calculated detailed WSS patterns in the carotid bifurcation of mice using a Fluid-structure interaction (FSI) approach. We subsequently fed the animals a high-fat diet and linked the results of the FSI simulations to those of atherosclerotic plaque location on a within-subject basis. However, these simulations were based on boundary conditions measured under anesthesia, while active mice might experience different hemodynamics. Moreover, the FSI technique for mouse-specific simulations is both time- and labor-intensive, and might be replaced by simpler and easier Computational Fluid Dynamics (CFD) simulations. The goal of the current work was (i) to compare WSS patterns based on anesthesia conditions to those representing active resting and exercising conditions; and (ii) to compare WSS patterns based on FSI simulations to those based on steady-state and transient CFD simulations. METHODS For each of the 3 computational techniques (steady state CFD, transient CFD, FSI) we performed 5 simulations: 1 for anesthesia, 2 for conscious resting conditions and 2 more for conscious active conditions. The inflow, pressure and heart rate were scaled according to representative in vivo measurements obtained from literature. RESULTS When normalized by the maximal shear stress value, shear stress patterns were similar for the 3 computational techniques. For all activity levels, steady state CFD led to an overestimation of WSS values, while FSI simulations yielded a clear increase in WSS reversal at the outer side of the sinus of the external carotid artery that was not visible in transient CFD-simulations. Furthermore, the FSI simulations in the highest locomotor activity state showed a flow recirculation zone in the external carotid artery that was not present under anesthesia. This recirculation went hand in hand with locally increased WSS reversal. CONCLUSIONS Our data show that FSI simulations are not necessary to obtain normalized WSS patterns, but indispensable to assess the oscillatory behavior of the WSS in mice. Flow recirculation and WSS reversal at the external carotid artery may occur during high locomotor activity while they are not present under anesthesia. These phenomena might thus influence plaque formation to a larger extent than what was previously assumed.
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Affiliation(s)
- David De Wilde
- IBiTech-bioMMeda, Ghent University-IMinds Medical IT, Ghent, Belgium
| | - Bram Trachet
- IBiTech-bioMMeda, Ghent University-IMinds Medical IT, Ghent, Belgium; Institute of Bioengineering, EPFL, Lausanne, Switzerland.
| | - Guido De Meyer
- Division of Physiopharmacology, University of Antwerp, Antwerp, Belgium
| | - Patrick Segers
- IBiTech-bioMMeda, Ghent University-IMinds Medical IT, Ghent, Belgium
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17
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Characterization of Hemodynamics in Great Arteries of Wild-Type Mouse Using Computational Fluid Dynamics Based on Ultrasound Images. Ultrasound Q 2016; 32:51-7. [PMID: 26938034 DOI: 10.1097/ruq.0000000000000164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Hemodynamic factors in cardiovascular system are hypothesized to play a significant role in causing structural heart development. It is thus important to improve our understanding of velocity characteristics and parameters. We present such a study on wild-type mouse to characterize the vessel geometry, flow pattern, and wall shear stress in great arteries. Microultrasound imaging for small animals was used to measure blood boundary and velocity of the great arteries. Subsequently, specimens' flow boundary conditions were used for 3-dimensional reconstructions of the great artery and aortic arch dimensions, and blood flow velocity data were input into subject-specific computational fluid dynamics for modeling hemodynamics. Measurement by microultrasound imaging showed that blood velocities in the great artery and aortic arch had strong correlations with vascular sizes, whereas blood pressure had a weak trend in relation to vascular size. Wall shear stress magnitude increased when closer to arterial branches and reduced proximally in the aortic root and distally in the descending aorta, and the parameters were related to the fluid mechanics in branches in some degree. We developed a method to investigate fluid mechanics in mouse arteries, using a combination of microultrasound and computational fluid dynamics, and demonstrated its ability to reveal detailed geometric, kinematic, and fluid mechanics parameters.
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WIPUTRA H, LIM GL, CHIA DAK, MATTAR CNZ, BISWAS A, YAP CH. Methods for fluid dynamics simulations of human fetal cardiac chambers based on patient-specific 4D ultrasound scans. ACTA ACUST UNITED AC 2016. [DOI: 10.1299/jbse.15-00608] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Hadi WIPUTRA
- Department of Biomedical Engineering, National University of Singapore
| | - Guat Ling LIM
- Department of Obstetrics and Gynecology, Yong Loo Lin School of Medicine, National University of Singapore, National University Health Systems
| | - Dawn Ah Kiow CHIA
- Department of Obstetrics and Gynecology, Yong Loo Lin School of Medicine, National University of Singapore, National University Health Systems
| | - Citra Nurfarah Zaini MATTAR
- Department of Obstetrics and Gynecology, Yong Loo Lin School of Medicine, National University of Singapore, National University Health Systems
| | - Arijit BISWAS
- Department of Obstetrics and Gynecology, Yong Loo Lin School of Medicine, National University of Singapore, National University Health Systems
| | - Choon Hwai YAP
- Department of Biomedical Engineering, National University of Singapore
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19
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Lai CQ, Lim GL, Jamil M, Mattar CNZ, Biswas A, Yap CH. Fluid mechanics of blood flow in human fetal left ventricles based on patient-specific 4D ultrasound scans. Biomech Model Mechanobiol 2015; 15:1159-72. [DOI: 10.1007/s10237-015-0750-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2015] [Accepted: 12/01/2015] [Indexed: 11/28/2022]
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20
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3D Reconstruction of Chick Embryo Vascular Geometries Using Non-invasive High-Frequency Ultrasound for Computational Fluid Dynamics Studies. Ann Biomed Eng 2015; 43:2780-93. [PMID: 26014359 DOI: 10.1007/s10439-015-1339-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2015] [Accepted: 05/13/2015] [Indexed: 12/17/2022]
Abstract
Recent animal studies have provided evidence that prenatal blood flow fluid mechanics may play a role in the pathogenesis of congenital cardiovascular malformations. To further these researches, it is important to have an imaging technique for small animal embryos with sufficient resolution to support computational fluid dynamics studies, and that is also non-invasive and non-destructive to allow for subject-specific, longitudinal studies. In the current study, we developed such a technique, based on ultrasound biomicroscopy scans on chick embryos. Our technique included a motion cancelation algorithm to negate embryonic body motion, a temporal averaging algorithm to differentiate blood spaces from tissue spaces, and 3D reconstruction of blood volumes in the embryo. The accuracy of the reconstructed models was validated with direct stereoscopic measurements. A computational fluid dynamics simulation was performed to model fluid flow in the generated construct of a Hamburger-Hamilton (HH) stage 27 embryo. Simulation results showed that there were divergent streamlines and a low shear region at the carotid duct, which may be linked to the carotid duct's eventual regression and disappearance by HH stage 34. We show that our technique has sufficient resolution to produce accurate geometries for computational fluid dynamics simulations to quantify embryonic cardiovascular fluid mechanics.
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Kowalski WJ, Pekkan K, Tinney JP, Keller BB. Investigating developmental cardiovascular biomechanics and the origins of congenital heart defects. Front Physiol 2014; 5:408. [PMID: 25374544 PMCID: PMC4204442 DOI: 10.3389/fphys.2014.00408] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2014] [Accepted: 10/02/2014] [Indexed: 11/24/2022] Open
Abstract
Innovative research on the interactions between biomechanical load and cardiovascular (CV) morphogenesis by multiple investigators over the past 3 decades, including the application of bioengineering approaches, has shown that the embryonic heart adapts both structure and function in order to maintain cardiac output to the rapidly growing embryo. Acute adaptive hemodynamic mechanisms in the embryo include the redistribution of blood flow within the heart, dynamic adjustments in heart rate and developed pressure, and beat to beat variations in blood flow and vascular resistance. These biomechanically relevant events occur coincident with adaptive changes in gene expression and trigger adaptive mechanisms that include alterations in myocardial cell growth and death, regional and global changes in myocardial architecture, and alterations in central vascular morphogenesis and remodeling. These adaptive mechanisms allow the embryo to survive these biomechanical stresses (environmental, maternal) and to compensate for developmental errors (genetic). Recent work from numerous laboratories shows that a subset of these adaptive mechanisms is present in every developing multicellular organism with a “heart” equivalent structure. This chapter will provide the reader with an overview of some of the approaches used to quantify embryonic CV functional maturation and performance, provide several illustrations of experimental interventions that explore the role of biomechanics in the regulation of CV morphogenesis including the role of computational modeling, and identify several critical areas for future investigation as available experimental models and methods expand.
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Affiliation(s)
- William J Kowalski
- Cardiovascular Innovation Institute, University of Louisville Louisville, KY, USA ; Department of Pediatrics, University of Louisville Louisville, KY, USA
| | - Kerem Pekkan
- Department of Biomedical Engineering, Carnegie Mellon University Pittsburgh, PA, USA
| | - Joseph P Tinney
- Cardiovascular Innovation Institute, University of Louisville Louisville, KY, USA ; Department of Pediatrics, University of Louisville Louisville, KY, USA
| | - Bradley B Keller
- Cardiovascular Innovation Institute, University of Louisville Louisville, KY, USA ; Department of Pediatrics, University of Louisville Louisville, KY, USA ; Department of Biomedical Engineering, Carnegie Mellon University Pittsburgh, PA, USA
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