In this paper,we investigate the impact of coronary artery dynamics on the wall shear stress(WSS)vector field topology by comparing fluid–structure interaction(FSI)and computational fluid dynamics(CFD)techniques.As o...In this paper,we investigate the impact of coronary artery dynamics on the wall shear stress(WSS)vector field topology by comparing fluid–structure interaction(FSI)and computational fluid dynamics(CFD)techniques.As one of the most common causes of death globally,coronary artery disease(CAD)is a significant economic burden;however,novel approaches are still needed to improve our ability to predict its progression.FSI can include the unique dynamical factors present in the coronary vasculature.To investigate the impact of these dynamical factors,we study an idealized artery model with sequential stenosis.The transient simulations made use of the hyperelastic artery and lipid constitutive equations,non‐Newtonian blood viscosity,and the characteristic out‐of‐phase pressure and velocity distribution of the left anterior descending coronary artery.We compare changes to established metrics of time‐averaged WSS(TAWSS)and the oscillatory shear index(OSI)to changes in the emerging WSS divergence,calculated here in a modified version to handle the deforming mesh of FSI simulations.Results suggest that the motion of the artery can impact downstream patterns in both divergence and OSI.WSS magnitude is also decreased by up to 57%due to motion in some regions.WSS divergence patterns varied most significantly between simulations over the systolic period,the time of the largest displacements.This investigation highlights that coronary dynamics could impact markers of potential CAD progression and warrants further detailed investigations in more diverse geometries and patient cases.展开更多
A fundamental challenge in endoscopy is how to fabricate a small fiber-optic probe that can achieve comparable function to devices with large,complicated optics.To achieve high resolution over an extended depth of foc...A fundamental challenge in endoscopy is how to fabricate a small fiber-optic probe that can achieve comparable function to devices with large,complicated optics.To achieve high resolution over an extended depth of focus(DOF),the application of needle-like beams has been proposed.However,existing methods for miniaturized needle-beam designs fail to adequately correct astigmatism and other monochromatic aberrations,limiting the resolution of at least one axis.Here,we describe an approach to realize freeform beam-shaping endoscopic probes via two-photon polymerization three-dimensional(3D)printing.We present a design achieving<8μm lateral resolution with a DOF of∼800μm.The probe has a diameter of<260μm(without the torque coil and catheters)and is fabricated using a single printing step directly on the optical fiber.The probe was successfully utilized for intravascular imaging in living diabetic swine at multiple time points,as well as human atherosclerotic plaques ex vivo.To the best of our knowledge,this is the first report of a 3D-printed micro-optic for in vivo imaging of the coronary arteries.These results are a substantial step to enable the clinical adoption of both 3D-printed micro-optics and beam-tailoring devices.展开更多
基金Westpac Scholars Trust,Grant/Award Number:FL19518National Heart Foundation of Australia,Grant/Award Number:FLF102056National Health and Medical Research Council(NHMRC),Grant/Award Number:CDF1161506。
文摘In this paper,we investigate the impact of coronary artery dynamics on the wall shear stress(WSS)vector field topology by comparing fluid–structure interaction(FSI)and computational fluid dynamics(CFD)techniques.As one of the most common causes of death globally,coronary artery disease(CAD)is a significant economic burden;however,novel approaches are still needed to improve our ability to predict its progression.FSI can include the unique dynamical factors present in the coronary vasculature.To investigate the impact of these dynamical factors,we study an idealized artery model with sequential stenosis.The transient simulations made use of the hyperelastic artery and lipid constitutive equations,non‐Newtonian blood viscosity,and the characteristic out‐of‐phase pressure and velocity distribution of the left anterior descending coronary artery.We compare changes to established metrics of time‐averaged WSS(TAWSS)and the oscillatory shear index(OSI)to changes in the emerging WSS divergence,calculated here in a modified version to handle the deforming mesh of FSI simulations.Results suggest that the motion of the artery can impact downstream patterns in both divergence and OSI.WSS magnitude is also decreased by up to 57%due to motion in some regions.WSS divergence patterns varied most significantly between simulations over the systolic period,the time of the largest displacements.This investigation highlights that coronary dynamics could impact markers of potential CAD progression and warrants further detailed investigations in more diverse geometries and patient cases.
基金supported by the National Health and Medical Research Council Development(Grant No.2022337)the Ideas Grant(Grant No.2001646),the Investigator Grant(Grant No.2008462)+9 种基金the Heart Foundation Future Leader Fellowship(Grant Nos.105608 and 106656)the Hospital Research Foundation Project(Grant No.2022-CP-IDMH-014-83100)Australia-Germany Joint Research Co-operation Scheme(UA-DAAD)Baden-Wuerttemberg-Stiftung(Opterial)European Research Council(Advanced Grant Complexplas,PoC Grant 3DPrintedOptics)Bundesministerium für Bildung und Forschung(3DPrintedOptics,Integrated3Dprint,QR.X,QR.N)Deutsche Forschungsgemeinschaft(German Research Foundation)(Grant No.431314977/GRK2642)HORIZON EUROPE European Innovation Council(Grant No.IV-Lab 101115545)Carl-Zeiss Foundation(EndoPrint3D,QPhoton)University of Stuttgart(Terra Incognita).
文摘A fundamental challenge in endoscopy is how to fabricate a small fiber-optic probe that can achieve comparable function to devices with large,complicated optics.To achieve high resolution over an extended depth of focus(DOF),the application of needle-like beams has been proposed.However,existing methods for miniaturized needle-beam designs fail to adequately correct astigmatism and other monochromatic aberrations,limiting the resolution of at least one axis.Here,we describe an approach to realize freeform beam-shaping endoscopic probes via two-photon polymerization three-dimensional(3D)printing.We present a design achieving<8μm lateral resolution with a DOF of∼800μm.The probe has a diameter of<260μm(without the torque coil and catheters)and is fabricated using a single printing step directly on the optical fiber.The probe was successfully utilized for intravascular imaging in living diabetic swine at multiple time points,as well as human atherosclerotic plaques ex vivo.To the best of our knowledge,this is the first report of a 3D-printed micro-optic for in vivo imaging of the coronary arteries.These results are a substantial step to enable the clinical adoption of both 3D-printed micro-optics and beam-tailoring devices.
